[Results of nine years of the clinical and epidemiological survey on cryptococcosis in Colombia, 1997-2005].

PubMed

Lizarazo, Jairo; Linares, Melva; de Bedout, Catalina; Restrepo, Angela; Agudelo, Clara Inés; Castañeda, Elizabeth

2007-03-01

A national survey on cryptococcosis has been conducted in Colombia since 1997. The survey data recorded over a 9-year period, 1997 to 2005, was summarized. The format provided by the European Confederation of Medical Mycology was adapted with the correspondent permission. Over the 9 year period, 931 surveys were received from 76 centers. The associated disease syndromes were as follows: 891 (95.7%) were neurocryptococosis cases, 27 (2.9%) pulmonary disease, 5 (0.5%) cutaneous lesions, 2 (0.2%) ganglionar forms, 2 (0.2%) oropharyngeal lesions and one case (0.1%) each from peritonitis, liver lesion, cellulitis and urinary tract infection. Demographic data indicated 82.7% of the subjects were males, and 59.4% were between 20-39 years old; 25 children less than 16 years old were reported. The prevalent risk factor was HIV infection (78.1%). The mean annual incidence rate of cryptococcosis in the general population was 2.4 X 106 inhabitants, but in AIDS patients the rate rose to one in 3 X 103. The most frequent clinical features were headache (85.2%), nausea and vomiting (59.1%), fever (59.0%), mental changes (46.2%), meningeal signs (33.4%), cough (23.6%) and visual alterations or loss of vision (20.9%). Laboratory data showed that direct examination of cerebrospinal fluid (CSF) was positive in 92.8% cases and Cryptococcus was recovered in 90.3% of the cases. Cryptococcal antigen reactivity was 98.9% in CSF and 93.7% in serum samples. From 788 isolates submitted, 95.9% were C. neoformans var. grubii serotype A, 0.3% var. neoformans serotype D, 3.3% C. gattii serotype B and 0.5% C. gattii serotype C. The majority of patients were treated initially with amphotericin B. Cryptococcosis incidence has increased dramatically in Colombia with the AIDS pandemic and it can be considered as a sentinel marker for HIV infection.

MLST-Based Population Genetic Analysis in a Global Context Reveals Clonality amongst Cryptococcus neoformans var. grubii VNI Isolates from HIV Patients in Southeastern Brazil

PubMed Central

Ferreira-Paim, Kennio; Andrade-Silva, Leonardo; Fonseca, Fernanda M.; Ferreira, Thatiana B.; Mora, Delio J.; Andrade-Silva, Juliana; Khan, Aziza; Dao, Aiken; Reis, Eduardo C.; Almeida, Margarete T. G.; Maltos, Andre; Junior, Virmondes R.; Trilles, Luciana; Rickerts, Volker; Chindamporn, Ariya; Sykes, Jane E.; Cogliati, Massimo; Nielsen, Kirsten; Boekhout, Teun; Fisher, Matthew; Kwon-Chung, June; Engelthaler, David M.; Lazéra, Marcia; Meyer, Wieland; Silva-Vergara, Mario L.

2017-01-01

Cryptococcosis is an important fungal infection in immunocompromised individuals, especially those infected with HIV. In Brazil, despite the free availability of antiretroviral therapy (ART) in the public health system, the mortality rate due to Cryptococcus neoformans meningitis is still high. To obtain a more detailed picture of the population genetic structure of this species in southeast Brazil, we studied 108 clinical isolates from 101 patients and 35 environmental isolates. Among the patients, 59% had a fatal outcome mainly in HIV-positive male patients. All the isolates were found to be C. neoformans var. grubii major molecular type VNI and mating type locus alpha. Twelve were identified as diploid by flow cytometry, being homozygous (AαAα) for the mating type and by PCR screening of the STE20, GPA1, and PAK1 genes. Using the ISHAM consensus multilocus sequence typing (MLST) scheme, 13 sequence types (ST) were identified, with one being newly described. ST93 was identified from 81 (75%) of the clinical isolates, while ST77 and ST93 were identified from 19 (54%) and 10 (29%) environmental isolates, respectively. The southeastern Brazilian isolates had an overwhelming clonal population structure. When compared with populations from different continents based on data extracted from the ISHAM-MLST database (mlst.mycologylab.org) they showed less genetic variability. Two main clusters within C. neoformans var. grubii VNI were identified that diverged from VNB around 0.58 to 4.8 million years ago. PMID:28099434

[Cyptococcus gattii isolated from a cheetah (Acinonyx jubatus) in the National Zoo of Cuba].

PubMed

Polo Leal, Jorge Luis; Fernández Andreu, Carlos Manuel; Martínez Machín, Gerardo; Illnait Zaragozi, María Teresa; Perurena Lancha, Mayda Rosa

2010-01-01

Cryptoccosis--systemic mycosis caused by Cryptococcus species--has considerably raised its incidence in the last years, mainly associated with the human immunodeficiency virus infection. It has also been described in animals, but rare cases. a case of a female cheetah (Acinonyx jubatus) kept in the Nacional Zoo of Havana was presented. The animal came from South Africa. She began losing weight, and suffering asthenia, anorexia and breathing problems with abundant nasal secretion. mycological testing of these secretions disclosed the presence of serotype B Cryptococcus gattii. Because of the origin and captive condition of the animal, it was believed that the infection had been latent for 16 months at least. up to the present, in Cuba, all clinical Cryptococcus isolates were C. neoformans var. grubii, so it is considered that the infection was caught in the country of origin of the female cheetah. This is the first C. gattii isolate in Cuba from an animal coming from South Africa where this fungus is endemic.

CRYPTOCOCCUS NEOFORMANS VAR. GRUBII-ASSOCIATED RENAL AMYLOIDOSIS CAUSING PROTEIN-LOSING NEPHROPATHY IN A RED KANGAROO (MACROPUS RUFUS).

PubMed

Thurber, Mary Irene; Gjeltema, Jenessa; Sheley, Matthew; Wack, Ray F

2017-09-01

A 10-year-old male castrated red kangaroo (Macropus rufus) presented with mandibular swelling. Examination findings included pitting edema with no dental disease evident on examination or radiographs. The results of blood work were moderate azotemia, hypoalbuminemia, and severely elevated urine protein:creatinine ratio (9.9). Radiographs showed an interstitial pattern of the caudal right lung, and an abdominal ultrasound demonstrated scant effusion. Symptomatic and empirical therapy with antibiotics, anti-inflammatory drugs, and an angiotensin-converting enzyme (ACE) inhibitor did not resolve clinical signs. Due to poor prognosis and declining quality of life, euthanasia was elected. Necropsy revealed chronic granulomatous pneumonia of the caudal right lung lobe with intralesional Cryptococcus, identified as C. neoformans var. grubii by DNA sequencing. Severe bilateral glomerular and tubulointerstitial amyloidosis induced protein-losing nephropathy, leading to tri-cavitary effusion, subcutaneous edema, and cachexia. The authors speculate that renal amyloidosis was associated with chronic cryptococcal pneumonia in this red kangaroo.

Cryptococcosis Serotypes Impact Outcome and Provide Evidence of Cryptococcus neoformans Speciation.

PubMed

Desnos-Ollivier, Marie; Patel, Sweta; Raoux-Barbot, Dorothée; Heitman, Joseph; Dromer, Françoise

2015-06-09

Cryptococcus neoformans is a human opportunistic fungal pathogen causing severe disseminated meningoencephalitis, mostly in patients with cellular immune defects. This species is divided into three serotypes: A, D, and the AD hybrid. Our objectives were to compare population structures of serotype A and D clinical isolates and to assess whether infections with AD hybrids differ from infections with the other serotypes. For this purpose, we analyzed 483 isolates and the corresponding clinical data from 234 patients enrolled during the CryptoA/D study or the nationwide survey on cryptococcosis in France. Isolates were characterized in terms of ploidy, serotype, mating type, and genotype, utilizing flow cytometry, serotype- and mating type-specific PCR amplifications, and multilocus sequence typing (MLST) methods. Our results suggest that C. neoformans serotypes A and D have different routes of multiplication (primarily clonal expansion versus recombination events for serotype A and serotype D, respectively) and important genomic differences. Cryptococcosis includes a high proportion of proven or probable infections (21.5%) due to a mixture of genotypes, serotypes, and/or ploidies. Multivariate analysis showed that parameters independently associated with failure to achieve cerebrospinal fluid (CSF) sterilization by week 2 were a high serum antigen titer, the lack of flucytosine during induction therapy, and the occurrence of mixed infection, while infections caused by AD hybrids were more likely to be associated with CSF sterilization. Our study provides additional evidence for the possible speciation of C. neoformans var. neoformans and grubii and highlights the importance of careful characterization of causative isolates. Cryptococcus neoformans is an environmental fungus causing severe disease, estimated to be responsible for 600,000 deaths per year worldwide. This species is divided into serotypes A and D and an AD hybrid, and these could be considered two different species and an interspecies hybrid. The objectives of our study were to compare population structures of serotype A and serotype D and to assess whether infections with AD hybrids differ from infections with serotype A or D isolates in terms of clinical presentation and outcome. For this purpose, we used clinical data and strains from patients diagnosed with cryptococcosis in France. Our results suggest that, according to the serotype, isolates have different routes of multiplication and high genomic differences, confirming the possible speciation of serotypes A and D. Furthermore, we observed a better prognosis for infections caused by AD hybrid than those caused by serotype A or D, at least for those diagnosed in France. Copyright © 2015 Desnos-Ollivier et al.

Isolates of Cryptococcus neoformans from Infected Animals Reveal Genetic Exchange in Unisexual, α Mating Type Populations▿ †

PubMed Central

Bui, Tien; Lin, Xiaorong; Malik, Richard; Heitman, Joseph; Carter, Dee

2008-01-01

Sexual reproduction and genetic exchange are important for the evolution of fungal pathogens and for producing potentially infective spores. Studies to determine whether sex occurs in the pathogenic yeast Cryptococcus neoformans var. grubii have produced enigmatic results, however: basidiospores are the most likely infective propagules, and clinical isolates are fertile and genetically diverse, consistent with a sexual species, but almost all populations examined consist of a single mating type and have little evidence for genetic recombination. The choice of population is critical when looking for recombination, particularly when significant asexual propagation is likely and when latency may complicate assessing the origin of an isolate. We therefore selected isolates from infected animals living in the region of Sydney, Australia, with the assumption that the relatively short life spans and limited travels of the animal hosts would provide a very defined population. All isolates were mating type α and were of molecular genotype VNI or VNII. A lack of linkage disequilibrium among loci suggested that genetic exchange occurred within both genotype groups. Four diploid VNII isolates that produced filaments and basidium-like structures when cultured in proximity to an a mating type strain were found. Recent studies suggest that compatible α-α unions can occur in C. neoformans var. neoformans populations and in populations of the sibling species Cryptococcus gattii. As a mating type strains of C. neoformans var. grubii have never been found in Australia, or in the VNII molecular type globally, the potential for α-α unions is evidence that α-α unisexual mating maintains sexual recombination and diversity in this pathogen and may produce infectious propagules. PMID:18552280

Cryptococcemia. An analysis of 28 cases with emphasis on the clinical outcome and its etiologic agent.

PubMed

Pasqualotto, Alessandro Comarú; Bittencourt Severo, Cecília; de Mattos Oliveira, Flávio; Severo, Luiz Carlos

2004-09-01

Clinical protocols of 28 cases of cryptococcemia studied between April 1995 and November 2002 were reviewed. The varieties of Cryptococcus neorformans, the underlying disease, and the severity and outcome of the disease were emphasized. Most patients were immunossupressed (89.3% with AIDS) and Cryptococcus neoformans var. grubii was the main recovered variety (92.8%). Regardless of antifungal treatment, in-hospital mortality was 41% strongly associated with APACHE II score, >14 (p<0.01).

First case of disseminated cryptococcosis in a Gorilla gorilla.

PubMed

Mischnik, Alexander; Stockklausner, Julia; Hohneder, Nicole; Jensen, Henrik E; Zimmermann, Stefan; Reuss, David E; Rickerts, Volker; Tintelnot, Kathrin; Stockklausner, Clemens

2014-11-01

In humans, Cryptococcus mainly infects individuals with HIV infection or other types of immunosuppression. Here, we report the first case of disseminated cryptococcosis in a simian immunodeficiency virus-negative 27-year-old female Gorilla gorilla presenting with lethargy, progressive weight loss and productive cough. The diagnosis was confirmed by positive lung biopsy culture, serum cryptococcal antigen, and cerebral histopathology demonstrating encapsulated yeasts. Molecular characterisation of lung culture isolate yielded Cryptococcus neoformans var. grubii. An immune-deficiency could not be demonstrated. © 2014 Blackwell Verlag GmbH.

Shigella from humans in Thailand during 1993 to 2006: spatial-time trends in species and serotype distribution.

PubMed

Bangtrakulnonth, Aroon; Vieira, Antonio R; Lo Fo Wong, Danilo M A; Pornreongwong, Srirat; Pulsrikarn, Chaiwat; Sawanpanyalert, Pathom; Hendriksen, Rene S; Aarestrup, Frank M

2008-12-01

In Thailand during 1993-2006, a total of 9063 Shigella isolates from different medical centers were serotyped and trends over time and spatial clustering analyzed. Of 3583 cases with age information, 1315 (37%) cases were from children between 0 and 4 years and 684 (19%) from children between 5 and 8 years. Most infections were recorded during 1993-1994 (> 1500 per year), decreasing to < 200 in 2006. The relative species distribution also changed. During 1993-1994, Shigella flexneri accounted for 2241 (65%) of 3474 isolations. This proportion decreased to 64 (36%) of 176 infections in 2006. Most infections occurred during July and August, and fewest in December. S. flexneri clustered around Bangkok, and Shigella sonnei in southern Thailand. Most S. flexneri infections were caused by serotype 2a (1590 of 4035) followed by serotype var X (1249). For both serotypes, a pronounced decrease in the number of isolates occurred over time. A much smaller decrease was observed for serotype 3a isolates. Phase I S. sonnei was initially most common, but shifted gradually over phase I, II, to only phase II. No differences in spatial distribution were found. The three most common S. flexneri serotypes all clustered in, around, and west of Bangkok. Serotypes 2a and 3a also clustered in southern Thailand, whereas var X clustered north and northeast of Bangkok. In conclusion, looking at Shigella species, Thailand changed from being a developing country to a developed country between 1995 and 1996. In addition, major shifts in the types of S. sonnei were observed as were differences in spatial clustering of S. flexneri and S. sonnei and S. flexneri serotypes.

Ecological surveys of the Cryptococcus species complex in China.

PubMed

Li, An-Sheng; Pan, Wei-Hua; Wu, Shao-Xi; Hideaki, Taguchi; Guo, Ning-Ru; Shen, Yong-Nian; Lu, Gui-Xia; Pan, Ru-Gui; Zhu, Miao-Chang; Chen, Min; Shi, Wei-Ming; Liao, Wan-Qing

2012-02-01

Despite recent reports on the molecular epidemiology of cryptococcal infections in China, clinical isolates have been mostly reported from human immunodeficiency virus (HIV)-negative patients, and environmental isolates from China have rarely been included. The aim of this study was to investigate the ecological profile of Cryptococcus (C.) neoformans and C. gattii in China. A survey was performed in 10 cities from 20°N (North latitude) to 50°N and in a Eucalyptus (E.) camaldulensis forestry farm at the Guixi forestry center, China. Six hundred and twenty samples of pigeon droppings from 10 cities and 819 E. camaldulensis tree samples were collected and inoculated on caffeic acid cornmeal agar (CACA). The brown-colored colonies were recultured to observe their morphology, growth on canavanine-glycine-bromothymol-blue (CGB) medium, phenol oxidase and urease activities, serotype and mating type. There were obvious differences in the positive sample rates of C. neoformans in pigeon droppings collected from the different cities, ranging from 50% in the cities located at latitudes from 30°N - 40°N, 29% at 20°N - 30°N and 13% at 40°N - 50°N. There were no differences in positive bevy rates (approximately 80%) among the three grouped cities. Mycological tests of 101 isolates purified from pigeon droppings revealed that they were C. neoformans var. grubii. We also observed variable capsular size around the C. neoformans cells in colonies with variable melanin production and the bio-adhesion of the natural C. neoformans cells with other microorganisms. One urease-negative C. neoformans isolate was isolated from pigeon droppings in Jinan city. No C. gattii was isolated in this study.

Inhibition of the calcineurin pathway by two tannins, chebulagic acid and chebulanin, isolated from Harrisonia abyssinica Oliv.

PubMed

Lee, Won Jeong; Moon, Jae Sun; Kim, Sung In; Kim, Young Tae; Nash, Oyekanmi; Bahn, Yong-Sun; Kim, Sung Uk

2014-10-01

In order to discover and develop novel signaling inhibitors from plants, a screening system was established targeting the two-component system of Cryptococcus neoformans by using the wild type and a calcineurin mutant of C. neoformans, based on the counter-regulatory action of high-osmolarity glycerol (Hog1) mitogen-activated protein kinase and the calcineurin pathways in C. neoformans. Among 10,000 plant extracts, that from Harrisonia abyssinica Oliv. exhibited the most potent inhibitory activity against C. neoformans var. grubii H99 with fludioxonil. Bioassay-guided fractionation was used to isolate two bioactive compounds from H. abyssinica, and these compounds were identified as chebulagic acid and chebulanin using spectroscopic methods. These compounds specifically inhibited the calcineurin pathway in C. neoformans. Moreover, they exhibited potent antifungal activities against various human pathogenic fungi with minimum inhibitory concentrations ranging from 0.25 to over 64 µg/ml.

Fundamental niche prediction of the pathogenic yeasts Cryptococcus neoformans and Cryptococcus gattii in Europe.

PubMed

Cogliati, Massimo; Puccianti, Erika; Montagna, Maria T; De Donno, Antonella; Susever, Serdar; Ergin, Cagri; Velegraki, Aristea; Ellabib, Mohamed S; Nardoni, Simona; Macci, Cristina; Trovato, Laura; Dipineto, Ludovico; Rickerts, Volker; Akcaglar, Sevim; Mlinaric-Missoni, Emilija; Bertout, Sebastien; Vencà, Ana C F; Sampaio, Ana C; Criseo, Giuseppe; Ranque, Stéphane; Çerikçioğlu, Nilgün; Marchese, Anna; Vezzulli, Luigi; Ilkit, Macit; Desnos-Ollivier, Marie; Pasquale, Vincenzo; Polacheck, Itzhack; Scopa, Antonio; Meyer, Wieland; Ferreira-Paim, Kennio; Hagen, Ferry; Boekhout, Teun; Dromer, Françoise; Varma, Ashok; Kwon-Chung, Kyung J; Inácio, Joäo; Colom, Maria F

2017-10-01

Fundamental niche prediction of Cryptococcus neoformans and Cryptococcus gattii in Europe is an important tool to understand where these pathogenic yeasts have a high probability to survive in the environment and therefore to identify the areas with high risk of infection. In this study, occurrence data for C. neoformans and C. gattii were compared by MaxEnt software with several bioclimatic conditions as well as with soil characteristics and land use. The results showed that C. gattii distribution can be predicted with high probability along the Mediterranean coast. The analysis of variables showed that its distribution is limited by low temperatures during the coldest season, and by heavy precipitations in the driest season. C. neoformans var. grubii is able to colonize the same areas of C. gattii but is more tolerant to cold winter temperatures and summer precipitations. In contrast, the C. neoformans var. neoformans map was completely different. The best conditions for its survival were displayed in sub-continental areas and not along the Mediterranean coasts. In conclusion, we produced for the first time detailed prediction maps of the species and varieties of the C. neoformans and C. gattii species complex in Europe and Mediterranean area. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Antimicrobial Octapeptin C4 Analogues Active against Cryptococcus Species.

PubMed

Chitty, Jessica L; Butler, Mark S; Suboh, Azzah; Edwards, David J; Cooper, Matthew A; Fraser, James A; Robertson, Avril A B

2018-02-01

Resistance to antimicrobials is a growing problem in both developed and developing countries. In nations where AIDS is most prevalent, the human fungal pathogen Cryptococcus neoformans is a significant contributor to mortality, and its growing resistance to current antifungals is an ever-expanding threat. We investigated octapeptin C4, from the cationic cyclic lipopeptide class of antimicrobials, as a potential new antifungal. Octapeptin C4 was a potent, selective inhibitor of this fungal pathogen with an MIC of 1.56 μg/ml. Further testing of octapeptin C4 against 40 clinical isolates of C. neoformans var. grubii or neoformans showed an MIC of 1.56 to 3.13 μg/ml, while 20 clinical isolates of C. neoformans var. gattii had an MIC of 0.78 to 12.5 μg/ml. In each case, the MIC values for octapeptin C4 were equivalent to, or better than, current antifungal drugs fluconazole and amphotericin B. The negatively charged polysaccharide capsule of C. neoformans influences the pathogen's sensitivity to octapeptin C4, whereas the degree of melanization had little effect. Testing synthetic octapeptin C4 derivatives provided insight into the structure activity relationships, revealing that the lipophilic amino acid moieties are more important to the activity than the cationic diaminobutyric acid groups. Octapeptins have promising potential for development as anticryptococcal therapeutic agents. Copyright © 2018 Chitty et al.

Antimicrobial Octapeptin C4 Analogues Active against Cryptococcus Species

PubMed Central

Chitty, Jessica L.; Butler, Mark S.; Suboh, Azzah; Edwards, David J.; Cooper, Matthew A.; Fraser, James A.

2017-01-01

ABSTRACT Resistance to antimicrobials is a growing problem in both developed and developing countries. In nations where AIDS is most prevalent, the human fungal pathogen Cryptococcus neoformans is a significant contributor to mortality, and its growing resistance to current antifungals is an ever-expanding threat. We investigated octapeptin C4, from the cationic cyclic lipopeptide class of antimicrobials, as a potential new antifungal. Octapeptin C4 was a potent, selective inhibitor of this fungal pathogen with an MIC of 1.56 μg/ml. Further testing of octapeptin C4 against 40 clinical isolates of C. neoformans var. grubii or neoformans showed an MIC of 1.56 to 3.13 μg/ml, while 20 clinical isolates of C. neoformans var. gattii had an MIC of 0.78 to 12.5 μg/ml. In each case, the MIC values for octapeptin C4 were equivalent to, or better than, current antifungal drugs fluconazole and amphotericin B. The negatively charged polysaccharide capsule of C. neoformans influences the pathogen's sensitivity to octapeptin C4, whereas the degree of melanization had little effect. Testing synthetic octapeptin C4 derivatives provided insight into the structure activity relationships, revealing that the lipophilic amino acid moieties are more important to the activity than the cationic diaminobutyric acid groups. Octapeptins have promising potential for development as anticryptococcal therapeutic agents. PMID:29158283

The isolation of Cryptococcus neoformans from pigeon droppings and serotyping of naturally and clinically sourced isolates in China.

PubMed

Li, A; Nishimura, K; Taguchi, H; Tanaka, R; Wu, S; Miyaji, M

1993-10-01

This is the first report on the isolation of Cryptococcus neoformans from pigeon droppings in China and their serotypes. C. neoformans colonies which produced brown colonies on caffeic acid-cornmeal agar were found in Twenty-five out of thirty-six samples of pigeon droppings. Fifty-one colonies randomly picked from the positive samples were identified as C. neoformans by a commercially available kit for carbon source assimilation test and Christensen's urea agar. Forty (78%) out of the 51 strains were serotyped as A and 11 (22%) as AD. At the same time, seventeen out of nineteen clinical isolates were serotyped as A and 2 as B. There are three findings in our results. One is that only C. neoformans var. neoformans strains could be isolated from pigeon droppings, although the variety gattii strains were found in the clinical isolates obtained in the same geographic site in China. The second is that serotype A strains were most frequently seen in natural and clinical materials in the southeast part of China, and serotype AD strains were isolated in pigeon droppings but not in clinical materials. The third is that the coexistence of serotype A and AD cells of C. neoformans strains in same samples of pigeon droppings were observed.

Isolation, Identification and Molecular Typing of Cryptococcus neoformans from Pigeon Droppings and Other Environmental Sources in Tripoli, Libya.

PubMed

Ellabib, Mohamed S; Aboshkiwa, Mohamed A; Husien, Walid M; D'Amicis, Roberta; Cogliati, Massimo

2016-08-01

Cryptococcus neoformans and C. gattii are the major cause of fungal meningitis, a potentially lethal mycosis. Since pigeon excreta and other environmental sources can be considered a significant environmental reservoir of this species in urban areas, 100 samples of pigeon excreta and 420 samples from Eucalyptus camaldulensis and Olea europaea (olive tree) around the city of Tripoli, Libya, were collected. C. neoformans was isolated and identified using standard biochemical assays from 46 samples: 34 from pigeon droppings, 3 from Eucalyptus trees and 9 from olive trees. Molecular typing revealed that all isolates from pigeon droppings belonged to molecular type VNI (C. neoformans var. grubii) and mating type αA, whereas those from trees included also the molecular type VNII and VNIII (AD hybrids). The present study reports, for the first time, information about the distribution of species, mating types and molecular types of C. neoformans/C. gattii species complex in Libya.

Cryptococcus neoformans mates on pigeon guano: implications for the realized ecological niche and globalization.

PubMed

Nielsen, Kirsten; De Obaldia, Anna L; Heitman, Joseph

2007-06-01

The ecological niche that a species can occupy is determined by its resource requirements and the physical conditions necessary for survival. The niche to which an organism is most highly adapted is the realized niche, whereas the complete range of habitats that an organism can occupy represents the fundamental niche. The growth and development of Cryptococcus neoformans and Cryptococcus gattii on pigeon guano were examined to determine whether these two species occupy the same or different ecological niches. C. neoformans is a cosmopolitan pathogenic yeast that infects predominantly immunocompromised individuals, exists in two varieties (grubii [serotype A] and neoformans [serotype D]), and is commonly isolated from pigeon guano worldwide. By contrast, C. gattii often infects immunocompetent individuals and is associated with geographically restricted environments, most notably, eucalyptus trees. Pigeon guano supported the growth of both species, and a brown pigment related to melanin, a key virulence factor, was produced. C. neoformans exhibited prolific mating on pigeon guano, whereas C. gattii did not. The observations that C. neoformans completes the life cycle on pigeon guano but that C. gattii does not indicates that pigeon guano could represent the realized ecological niche for C. neoformans. Because C. gattii grows on pigeon guano but cannot sexually reproduce, pigeon guano represents a fundamental but not a realized niche for C. gattii. Based on these studies, we hypothesize that an ancestral Cryptococcus strain gained the ability to sexually reproduce in pigeon guano and then swept the globe.

Cryptococcus neoformans Mates on Pigeon Guano: Implications for the Realized Ecological Niche and Globalization▿

PubMed Central

Nielsen, Kirsten; De Obaldia, Anna L.; Heitman, Joseph

2007-01-01

The ecological niche that a species can occupy is determined by its resource requirements and the physical conditions necessary for survival. The niche to which an organism is most highly adapted is the realized niche, whereas the complete range of habitats that an organism can occupy represents the fundamental niche. The growth and development of Cryptococcus neoformans and Cryptococcus gattii on pigeon guano were examined to determine whether these two species occupy the same or different ecological niches. C. neoformans is a cosmopolitan pathogenic yeast that infects predominantly immunocompromised individuals, exists in two varieties (grubii [serotype A] and neoformans [serotype D]), and is commonly isolated from pigeon guano worldwide. By contrast, C. gattii often infects immunocompetent individuals and is associated with geographically restricted environments, most notably, eucalyptus trees. Pigeon guano supported the growth of both species, and a brown pigment related to melanin, a key virulence factor, was produced. C. neoformans exhibited prolific mating on pigeon guano, whereas C. gattii did not. The observations that C. neoformans completes the life cycle on pigeon guano but that C. gattii does not indicates that pigeon guano could represent the realized ecological niche for C. neoformans. Because C. gattii grows on pigeon guano but cannot sexually reproduce, pigeon guano represents a fundamental but not a realized niche for C. gattii. Based on these studies, we hypothesize that an ancestral Cryptococcus strain gained the ability to sexually reproduce in pigeon guano and then swept the globe. PMID:17449657

Salmonella serotype distribution in the Dutch broiler supply chain.

PubMed

van Asselt, E D; Thissen, J T N M; van der Fels-Klerx, H J

2009-12-01

Salmonella serotype distribution can give insight in contamination routes and persistence along a production chain. Therefore, it is important to determine not only Salmonella prevalence but also to specify the serotypes involved at the different stages of the supply chain. For this purpose, data from a national monitoring program in the Netherlands were used to estimate the serotype distribution and to determine whether this distribution differs for the available sampling points in the broiler supply chain. Data covered the period from 2002 to 2005, all slaughterhouses (n = 22), and the following 6 sampling points: departure from hatchery, arrival at the farm, departure from the farm, arrival at the slaughterhouse, departure from the slaughterhouse, and end of processing. Furthermore, retail data for 2005 were used for comparison with slaughterhouse data. The following serotypes were followed throughout the chain: Salmonella Enteritidis, Salmonella Typhimurium, Salmonella Paratyphi B var. Java (Salmonella Java), Salmonella Infantis, Salmonella Virchow, and Salmonella Mbandaka. Results showed that serotype distribution varied significantly throughout the supply chain (P < 0.05). Main differences were found at the farm and at the slaughterhouse (within one stage), and least differences were found between departure from one stage and arrival at the next stage. The most prominent result was the increase of Salmonella Java at farm level. This serotype remained the most prominent pathogen throughout the broiler supply chain up to the retail phase.

Low Diversity Cryptococcus neoformans Variety grubii Multilocus Sequence Types from Thailand Are Consistent with an Ancestral African Origin

PubMed Central

Simwami, Sitali P.; Khayhan, Kantarawee; Henk, Daniel A.; Aanensen, David M.; Boekhout, Teun; Hagen, Ferry; Brouwer, Annemarie E.; Harrison, Thomas S.; Donnelly, Christl A.; Fisher, Matthew C.

2011-01-01

The global burden of HIV-associated cryptococcal meningitis is estimated at nearly one million cases per year, causing up to a third of all AIDS-related deaths. Molecular epidemiology constitutes the main methodology for understanding the factors underpinning the emergence of this understudied, yet increasingly important, group of pathogenic fungi. Cryptococcus species are notable in the degree that virulence differs amongst lineages, and highly-virulent emerging lineages are changing patterns of human disease both temporally and spatially. Cryptococcus neoformans variety grubii (Cng, serotype A) constitutes the most ubiquitous cause of cryptococcal meningitis worldwide, however patterns of molecular diversity are understudied across some regions experiencing significant burdens of disease. We compared 183 clinical and environmental isolates of Cng from one such region, Thailand, Southeast Asia, against a global MLST database of 77 Cng isolates. Population genetic analyses showed that Thailand isolates from 11 provinces were highly homogenous, consisting of the same genetic background (globally known as VNI) and exhibiting only ten nearly identical sequence types (STs), with three (STs 44, 45 and 46) dominating our sample. This population contains significantly less diversity when compared against the global population of Cng, specifically Africa. Genetic diversity in Cng was significantly subdivided at the continental level with nearly half (47%) of the global STs unique to a genetically diverse and recombining population in Botswana. These patterns of diversity, when combined with evidence from haplotypic networks and coalescent analyses of global populations, are highly suggestive of an expansion of the Cng VNI clade out of Africa, leading to a limited number of genotypes founding the Asian populations. Divergence time testing estimates the time to the most common ancestor between the African and Asian populations to be 6,920 years ago (95% HPD 122.96 - 27,177.76). Further high-density sampling of global Cng STs is now necessary to resolve the temporal sequence underlying the global emergence of this human pathogen. PMID:21573144

Low diversity Cryptococcus neoformans variety grubii multilocus sequence types from Thailand are consistent with an ancestral African origin.

PubMed

Simwami, Sitali P; Khayhan, Kantarawee; Henk, Daniel A; Aanensen, David M; Boekhout, Teun; Hagen, Ferry; Brouwer, Annemarie E; Harrison, Thomas S; Donnelly, Christl A; Fisher, Matthew C

2011-04-01

The global burden of HIV-associated cryptococcal meningitis is estimated at nearly one million cases per year, causing up to a third of all AIDS-related deaths. Molecular epidemiology constitutes the main methodology for understanding the factors underpinning the emergence of this understudied, yet increasingly important, group of pathogenic fungi. Cryptococcus species are notable in the degree that virulence differs amongst lineages, and highly-virulent emerging lineages are changing patterns of human disease both temporally and spatially. Cryptococcus neoformans variety grubii (Cng, serotype A) constitutes the most ubiquitous cause of cryptococcal meningitis worldwide, however patterns of molecular diversity are understudied across some regions experiencing significant burdens of disease. We compared 183 clinical and environmental isolates of Cng from one such region, Thailand, Southeast Asia, against a global MLST database of 77 Cng isolates. Population genetic analyses showed that Thailand isolates from 11 provinces were highly homogenous, consisting of the same genetic background (globally known as VNI) and exhibiting only ten nearly identical sequence types (STs), with three (STs 44, 45 and 46) dominating our sample. This population contains significantly less diversity when compared against the global population of Cng, specifically Africa. Genetic diversity in Cng was significantly subdivided at the continental level with nearly half (47%) of the global STs unique to a genetically diverse and recombining population in Botswana. These patterns of diversity, when combined with evidence from haplotypic networks and coalescent analyses of global populations, are highly suggestive of an expansion of the Cng VNI clade out of Africa, leading to a limited number of genotypes founding the Asian populations. Divergence time testing estimates the time to the most common ancestor between the African and Asian populations to be 6,920 years ago (95% HPD 122.96 - 27,177.76). Further high-density sampling of global Cng STs is now necessary to resolve the temporal sequence underlying the global emergence of this human pathogen.

Refractory and/or Relapsing Cryptococcosis Associated with Acquired Immune Deficiency Syndrome: Clinical Features, Genotype, and Virulence Factors of Cryptococcus spp. Isolates.

PubMed

Nascimento, Erika; Vitali, Lucia H; Tonani, Ludmilla; Kress, Marcia R Von Zeska; Takayanagui, Osvaldo M; Martinez, Roberto

2016-05-04

Refractory and relapsing crytocococcosis in acquired immune deficiency syndrome (AIDS) patients have a poor prognosis. The risk factors for this complicated infection course were evaluated by comparing refractory and/or relapsing cryptococcosis in human immunodeficiency virus-coinfected patients (cohort 1) with another group of AIDS patients who adequately responded to antifungals (cohort 2). Except for one isolate of Cryptococcus gattii from a cohort 2 case, all other isolates were identified as Cryptococcus neoformans var. grubii, sex type α, genotype VNI, including Cryptococcus reisolated from the relapse or in the refractory state. No differences were observed with respect to Cryptococcus capsule size and in the melanin and phospholipase production. The cohort 1 patients presented higher prevalence of cryptococcemia, cerebral dissemination, chronic liver disease, and leucopenia, and have increased death rate. Apparently, the refractory and/or relapsing cryptococcosis in the AIDS patients were more related to the host and the extent of the infection than to the fungal characteristics. © The American Society of Tropical Medicine and Hygiene.

Literature-Based Gene Curation and Proposed Genetic Nomenclature for Cryptococcus

PubMed Central

Inglis, Diane O.; Skrzypek, Marek S.; Liaw, Edward; Moktali, Venkatesh; Sherlock, Gavin

2014-01-01

Cryptococcus, a major cause of disseminated infections in immunocompromised patients, kills over 600,000 people per year worldwide. Genes involved in the virulence of the meningitis-causing fungus are being characterized at an increasing rate, and to date, at least 648 Cryptococcus gene names have been published. However, these data are scattered throughout the literature and are challenging to find. Furthermore, conflicts in locus identification exist, so that named genes have been subsequently published under new names or names associated with one locus have been used for another locus. To avoid these conflicts and to provide a central source of Cryptococcus gene information, we have collected all published Cryptococcus gene names from the scientific literature and associated them with standard Cryptococcus locus identifiers and have incorporated them into FungiDB (www.fungidb.org). FungiDB is a panfungal genome database that collects gene information and functional data and provides search tools for 61 species of fungi and oomycetes. We applied these published names to a manually curated ortholog set of all Cryptococcus species currently in FungiDB, including Cryptococcus neoformans var. neoformans strains JEC21 and B-3501A, C. neoformans var. grubii strain H99, and Cryptococcus gattii strains R265 and WM276, and have written brief descriptions of their functions. We also compiled a protocol for gene naming that summarizes guidelines proposed by members of the Cryptococcus research community. The centralization of genomic and literature-based information for Cryptococcus at FungiDB will help researchers communicate about genes of interest, such as those related to virulence, and will further facilitate research on the pathogen. PMID:24813190

Literature-based gene curation and proposed genetic nomenclature for cryptococcus.

PubMed

Inglis, Diane O; Skrzypek, Marek S; Liaw, Edward; Moktali, Venkatesh; Sherlock, Gavin; Stajich, Jason E

2014-07-01

Cryptococcus, a major cause of disseminated infections in immunocompromised patients, kills over 600,000 people per year worldwide. Genes involved in the virulence of the meningitis-causing fungus are being characterized at an increasing rate, and to date, at least 648 Cryptococcus gene names have been published. However, these data are scattered throughout the literature and are challenging to find. Furthermore, conflicts in locus identification exist, so that named genes have been subsequently published under new names or names associated with one locus have been used for another locus. To avoid these conflicts and to provide a central source of Cryptococcus gene information, we have collected all published Cryptococcus gene names from the scientific literature and associated them with standard Cryptococcus locus identifiers and have incorporated them into FungiDB (www.fungidb.org). FungiDB is a panfungal genome database that collects gene information and functional data and provides search tools for 61 species of fungi and oomycetes. We applied these published names to a manually curated ortholog set of all Cryptococcus species currently in FungiDB, including Cryptococcus neoformans var. neoformans strains JEC21 and B-3501A, C. neoformans var. grubii strain H99, and Cryptococcus gattii strains R265 and WM276, and have written brief descriptions of their functions. We also compiled a protocol for gene naming that summarizes guidelines proposed by members of the Cryptococcus research community. The centralization of genomic and literature-based information for Cryptococcus at FungiDB will help researchers communicate about genes of interest, such as those related to virulence, and will further facilitate research on the pathogen. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Copper complexes containing thiosemicarbazones derived from 6-nitropiperonal: Antimicrobial and biophysical properties

NASA Astrophysics Data System (ADS)

Beckford, Floyd A.; Webb, Kelsey R.

2017-08-01

A series of four thiosemicarbazones from 6-nitropiperonal along with the corresponding copper complexes were synthesized. The biophysical characteristics of the complexes were investigated by the binding to DNA and human serum albumin. The binding to DNA is moderate; the binding constants run from (0.49-7.50) × 104 M- 1. In relation to HSA, the complexes interact strongly with binding constants on the order of 105 M- 1. The complexes also display antioxidant behavior as determined by the ability to scavenge diphenylpicrylhydrazyl (dpph) and nitric oxide radicals. The antimicrobial profiles of the compounds, tested against a panel of microbes including five of the ESKAPE pathogens (Staphylococcus aureus, MRSA, Escherichia coli, Klebsiella pneumoniae, MDR, Acinetobacter baumannii, Pseudomonas aeruginosa) and two yeasts (Candida albicans and Cryptococcus neoformans var. grubii), are also described. The compounds contain a core moiety that is similar to oxolinic acid, a quinolone antibiotic that targets DNA gyrase and topoisomerase (IV). The binding interaction between the complexes and these important antibacterial targets were studied by computational methods, chiefly docking studies. The calculated dissociation constants for the interaction with DNA gyrase B (from Staphylococcus aureus) range from 4.32 to 24.65 μM; the binding was much stronger to topoisomerase IV, with dissociation constants ranging from 0.37 to 1.27 μM.

Diversity and Antifungal Drug Susceptibility of Cryptococcus Isolates in Thailand.

PubMed

Worasilchai, Navaporn; Tangwattanachuleeporn, Marut; Meesilpavikkai, Kornvalee; Folba, Claudia; Kangogo, Mourine; Groß, Uwe; Weig, Michael; Bader, Oliver; Chindamporn, Ariya

2017-08-01

Yeasts of the Cryptococcus species complex are the causative agent of cryptococcosis, especially in human immunodeficiency virus (HIV) positive individuals. Cerebral or disseminated cryptococcosis has a very high mortality rate worldwide, including in Thailand. Additionally, an increasing rate of antifungal drug resistant cryptococcal isolates has been reported in several neighboring countries, complicating therapeutic approaches. To understand the situation of this infection in Thailand, we retrospectively investigated the molecular epidemiology and antifungal drug resistance in a collection of 74 clinical, 52 environmental and two veterinary isolates using the URA5-RFLP for typing and the EUCAST guideline for susceptibility testing. Where no EUCAST breakpoints (AMB and 5FC) were available, CLSI epidemiologic cutoff values were used for interpretation. Cryptococcal molecular type diversity showed most isolates were C. grubii, molecular type VNI. One clinical isolate was C. deuterogattii (mol. type VGII) and another C. grubii (mol. type VNII). One strain from environment was classified as C. grubii (mol. type VNII). No resistant strains were detected in this retrospective study for either of the antimycotics tested; however, monitoring of the epidemiology of Cryptococcus species in infected patients in Thailand needs to be continued to detect emergence of resistance. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

[1st environmental isolation of Cryptococcus neoformans var. gattii in Argentina].

PubMed

Davel, G; Abrantes, R; Brudny, M; Córdoba, S; Rodero, L; Canteros, C E; Perrotta, D

2003-01-01

Two strains of C. neoformans var. gattii serotype B were isolated from a park in Buenos Aires city, Argentina. Samples were collected in spring, rubbing with swabs on the inner hollow of Eucalyptus spp. and other trees, which were not identified at the collection moment. Samples were swabbed directly onto cafeic acid with antibiotic agar, then incubated at 28 degrees C and observed daily for a week. Isolates were recovered from cafeic acid medium showing characteristic colonies of the species that allowed differentiation from other microorganisms of the sample. Identification was performed using carbohydrate fermentation, assimilation of nitrogen and carbon sources, and urease and phenoloxidase detection. Strain variety was determined with canavanine-glicine-bromotimol blue agar medium (CGB). Genotypic characterization using AP-PCR with (GACA)4 aleatory primer showed that both band profiles could be differentiated by only one band. These two strains were isolated from tree species different from Eucalyptus spp. These isolates from natural sources demonstrate that C. neoformans var. gattii efosts in Buenos Aires city environment and that it is not necessarily associated with Eucalyptus spp. The presence of C. neoformansvar. gattii in the environment, detected for the first time in Argentina, may explain its sporadic association with human infections in the local population.

Microevolution of Serial Clinical Isolates of Cryptococcus neoformans var. grubii and C. gattii

PubMed Central

Farrer, Rhys A.; Giamberardino, Charles; Sakthikumar, Sharadha; Jones, Alexander; Yang, Timothy; Tenor, Jennifer L.; Wagih, Omar; Van Wyk, Marelize; Govender, Nelesh P.; Mitchell, Thomas G.; Litvintseva, Anastasia P.

2017-01-01

ABSTRACT The pathogenic species of Cryptococcus are a major cause of mortality owing to severe infections in immunocompromised as well as immunocompetent individuals. Although antifungal treatment is usually effective, many patients relapse after treatment, and in such cases, comparative analyses of the genomes of incident and relapse isolates may reveal evidence of determinative, microevolutionary changes within the host. Here, we analyzed serial isolates cultured from cerebrospinal fluid specimens of 18 South African patients with recurrent cryptococcal meningitis. The time between collection of the incident isolates and collection of the relapse isolates ranged from 124 days to 290 days, and the analyses revealed that, during this period within the patients, the isolates underwent several genetic and phenotypic changes. Considering the vast genetic diversity of cryptococcal isolates in sub-Saharan Africa, it was not surprising to find that the relapse isolates had acquired different genetic and correlative phenotypic changes. They exhibited various mechanisms for enhancing virulence, such as growth at 39°C, adaptation to stress, and capsule production; a remarkable amplification of ERG11 at the native and unlinked locus may provide stable resistance to fluconazole. Our data provide a deeper understanding of the microevolution of Cryptococcus species under pressure from antifungal chemotherapy and host immune responses. This investigation clearly suggests a promising strategy to identify novel targets for improved diagnosis, therapy, and prognosis. PMID:28270580

Neural Network Model for Survival and Growth of Salmonella enterica Serotype 8,20:-:z6 in Ground Chicken Thigh Meat during Cold Storage: Extrapolation to Other Serotypes.

PubMed

Oscar, T P

2015-10-01

Mathematical models that predict the behavior of human bacterial pathogens in food are valuable tools for assessing and managing this risk to public health. A study was undertaken to develop a model for predicting the behavior of Salmonella enterica serotype 8,20:-:z6 in chicken meat during cold storage and to determine how well the model would predict the behavior of other serotypes of Salmonella stored under the same conditions. To develop the model, ground chicken thigh meat (0.75 cm(3)) was inoculated with 1.7 log Salmonella 8,20:-:z6 and then stored for 0 to 8 -8 to 16°C. An automated miniaturized most-probable-number (MPN) method was developed and used for the enumeration of Salmonella. Commercial software (Excel and the add-in program NeuralTools) was used to develop a multilayer feedforward neural network model with one hidden layer of two nodes. The performance of the model was evaluated using the acceptable prediction zone (APZ) method. The number of Salmonella in ground chicken thigh meat stayed the same (P > 0.05) during 8 days of storage at -8 to 8°C but increased (P < 0.05) during storage at 9°C (+0.6 log) to 16°C (+5.1 log). The proportion of residual values (observed minus predicted values) in an APZ (pAPZ) from -1 log (fail-safe) to 0.5 log (fail-dangerous) was 0.939 for the data (n = 426 log MPN values) used in the development of the model. The model had a pAPZ of 0.944 or 0.954 when it was extrapolated to test data (n = 108 log MPN per serotype) for other serotypes (S. enterica serotype Typhimurium var 5-, Kentucky, Typhimurium, and Thompson) of Salmonella in ground chicken thigh meat stored for 0 to 8 days at -4, 4, 12, or 16°C under the same experimental conditions. A pAPZ of ≥0.7 indicates that a model provides predictions with acceptable bias and accuracy. Thus, the results indicated that the model provided valid predictions of the survival and growth of Salmonella 8,20:-:z6 in ground chicken thigh meat stored for 0 to 8 days at -8 to 16°C and that the model was validated for extrapolation to four other serotypes of Salmonella.

Horizontal Dissemination of Antimicrobial Resistance Determinants in Multiple Salmonella Serotypes following Isolation from the Commercial Swine Operation Environment after Manure Application.

PubMed

Pornsukarom, Suchawan; Thakur, Siddhartha

2017-10-15

The aim of this study was to characterize the plasmids carrying antimicrobial resistance (AMR) determinants in multiple Salmonella serotypes recovered from the commercial swine farm environment after manure application on land. Manure and soil samples were collected on day 0 before and after manure application on six farms in North Carolina, and sequential soil samples were recollected on days 7, 14, and 21 from the same plots. All environmental samples were processed for Salmonella , and their plasmid contents were further characterized. A total of 14 isolates including Salmonella enterica serotypes Johannesburg ( n = 2), Ohio ( n = 2), Rissen ( n = 1), Typhimurium var5- ( n = 5), Worthington ( n = 3), and 4,12:i:- ( n = 1), representing different farms, were selected for plasmid analysis. Antimicrobial susceptibility testing was done by broth microdilution against a panel of 14 antimicrobials on the 14 confirmed transconjugants after conjugation assays. The plasmids were isolated by modified alkaline lysis, and PCRs were performed on purified plasmid DNA to identify the AMR determinants and the plasmid replicon types. The plasmids were sequenced for further analysis and to compare profiles and create phylogenetic trees. A class 1 integron with an ANT(2″)-Ia- aadA2 cassette was detected in the 50-kb IncN plasmids identified in S Worthington isolates. We identified 100-kb and 90-kb IncI1 plasmids in S Johannesburg and S Rissen isolates carrying the bla CMY-2 and tet (A) genes, respectively. An identical 95-kb IncF plasmid was widely disseminated among the different serotypes and across different farms. Our study provides evidence on the importance of horizontal dissemination of resistance determinants through plasmids of multiple Salmonella serotypes distributed across commercial swine farms after manure application. IMPORTANCE The horizontal gene transfer of antimicrobial resistance (AMR) determinants located on plasmids is considered to be the main reason for the rapid proliferation and spread of drug resistance. The deposition of manure generated in swine production systems into the environment is identified as a potential source of AMR dissemination. In this study, AMR gene-carrying plasmids were detected in multiple Salmonella serotypes across different commercial swine farms in North Carolina. The plasmid profiles were characterized based on Salmonella serotype donors and incompatibility (Inc) groups. We found that different Inc plasmids showed evidence of AMR gene transfer in multiple Salmonella serotypes. We detected an identical 95-kb plasmid that was widely distributed across swine farms in North Carolina. These conjugable resistance plasmids were able to persist on land after swine manure application. Our study provides strong evidence of AMR determinant dissemination present in plasmids of multiple Salmonella serotypes in the environment after manure application. Copyright © 2017 American Society for Microbiology.

Disseminated, histologically confirmed Cryptococcus spp infection in a domestic ferret.

PubMed

Eshar, David; Mayer, Jörg; Parry, Nicola M; Williams-Fritze, Misty J; Bradway, Daniel S

2010-04-01

A 4-year-old castrated male domestic ferret from central Massachusetts was evaluated for weight loss over a 1.5-month period and for 2 days of retching, diarrhea, and signs of lethargy. It had been housed indoors, with 2 other ferrets, 2 cats, and humans that lacked signs or symptoms of disease. Physical examination revealed a thin body condition, tachypnea, an increase in respiratory effort, and retching. Splenomegaly was detected during abdominal palpation. Clinicopathologic analysis revealed lymphopenia, lactic acidosis, hypoglycemia, hypocalcemia, hypoalbuminemia, and hyperglobulinemia. A pulmonary bronchointerstitial pattern was evident on radiographs, and abdominal ultrasonography revealed a suspected pancreatic mass and mesenteric lymphadenopathy. After 2 weeks of medical treatment and once clinical signs resolved, an exploratory laparotomy was performed and a lymph node biopsy specimen was collected. Histologic evaluation of the specimen revealed Cryptococcus-like organisms. Antifungal treatment was initiated with itraconazole (PO) and amphotericin B (IV). The ferret died after 2 days of treatment. A full necropsy was performed, revealing multicentric cryptococcosis affecting the lungs, brain, spleen, and multiple lymph nodes. Paraffin-embedded, formalin-fixed lung tissue was submitted for DNA extraction, and the organism was identified as Cryptococcus neoformans var grubii. To the authors' knowledge, this is the first report of disseminated cryptococcosis in a North American ferret. This case is unique in that the ferret lived indoors, in a geographic region in which reports of cryptococcosis are rare. The genotyping technique used to identify the Cryptococcus strain can aid in better understanding the epidemiology of cryptococcosis.

Multilocus Sequence Typing of Serially Collected Isolates of Cryptococcus from HIV-Infected Patients in South Africa

PubMed Central

Van Wyk, Marelize; Govender, Nelesh P.; Litvintseva, Anastasia P.

2014-01-01

Patients with cryptococcal meningitis in sub-Saharan Africa frequently relapse following treatment. The natural history and etiology of these recurrent episodes warrant investigation. Here, we used multilocus sequence typing (MLST) to compare the molecular genotypes of strains of Cryptococcus neoformans and Cryptococcus gattii isolated from serial episodes of cryptococcal meningitis that were separated by at least 110 days. The most common MLST genotypes among the isolates were the dominant global clinical genotypes (M5 and M4) of molecular type VNI, as well as the VNI genotypes apparently restricted to southern Africa. In addition, there was considerable genetic diversity among these South African isolates, as 15% of the patients had unique genotypes. Eleven percent of the patients were reinfected with a genetically different strain following their initial diagnosis and treatment. However, the majority of serial episodes (89%) were caused by strains with the same genotype as the original strain. These results indicate that serial episodes of cryptococcosis in South Africa are frequently associated with persistence or relapse of the original infection. Using a reference broth microdilution method, we found that the serial isolates of 11% of the patients infected with strains of C. neoformans var. grubii with identical genotypes exhibited ≥4-fold increases in the MICs to fluconazole. Therefore, these recurrent episodes may have been precipitated by inadequate induction or consolidation of antifungal treatment and occasionally may have been due to increased resistance to fluconazole, which may have developed during the chronic infection. PMID:24648562

Illuminating choices for library prep: a comparison of library preparation methods for whole genome sequencing of Cryptococcus neoformans using Illumina HiSeq.

PubMed

Rhodes, Johanna; Beale, Mathew A; Fisher, Matthew C

2014-01-01

The industry of next-generation sequencing is constantly evolving, with novel library preparation methods and new sequencing machines being released by the major sequencing technology companies annually. The Illumina TruSeq v2 library preparation method was the most widely used kit and the market leader; however, it has now been discontinued, and in 2013 was replaced by the TruSeq Nano and TruSeq PCR-free methods, leaving a gap in knowledge regarding which is the most appropriate library preparation method to use. Here, we used isolates from the pathogenic fungi Cryptococcus neoformans var. grubii and sequenced them using the existing TruSeq DNA v2 kit (Illumina), along with two new kits: the TruSeq Nano DNA kit (Illumina) and the NEBNext Ultra DNA kit (New England Biolabs) to provide a comparison. Compared to the original TruSeq DNA v2 kit, both newer kits gave equivalent or better sequencing data, with increased coverage. When comparing the two newer kits, we found little difference in cost and workflow, with the NEBNext Ultra both slightly cheaper and faster than the TruSeq Nano. However, the quality of data generated using the TruSeq Nano DNA kit was superior due to higher coverage at regions of low GC content, and more SNPs identified. Researchers should therefore evaluate their resources and the type of application (and hence data quality) being considered when ultimately deciding on which library prep method to use.

Cryptococcal transmigration across a model brain blood-barrier: evidence of the Trojan horse mechanism and differences between Cryptococcus neoformans var. grubii strain H99 and Cryptococcus gattii strain R265.

PubMed

Sorrell, Tania C; Juillard, Pierre-Georges; Djordjevic, Julianne T; Kaufman-Francis, Keren; Dietmann, Anelia; Milonig, Alban; Combes, Valery; Grau, Georges E R

2016-01-01

Cryptococcus neoformans (Cn) and Cryptococcus gattii (Cg) cause neurological disease and cross the BBB as free cells or in mononuclear phagocytes via the Trojan horse mechanism, although evidence for the latter is indirect. There is emerging evidence that Cn and the North American outbreak Cg strain (R265) more commonly cause neurological and lung disease, respectively. We have employed a widely validated in vitro model of the BBB, which utilizes the hCMEC/D3 cell line derived from human brain endothelial cells (HBEC) and the human macrophage-like cell line, THP-1, to investigate whether transport of dual fluorescence-labelled Cn and Cg across the BBB occurs within macrophages. We showed that phagocytosis of Cn by non-interferon (IFN)-γ stimulated THP-1 cells was higher than that of Cg. Although Cn and Cg-loaded THP-1 bound similarly to TNF-activated HBECs under shear stress, more Cn-loaded macrophages were transported across an intact HBEC monolayer, consistent with the predilection of Cn for CNS infection. Furthermore, Cn exhibited a higher rate of expulsion from transmigrated THP-1 compared with Cg. Our results therefore provide further evidence for transmigration of both Cn and Cg via the Trojan horse mechanism and a potential explanation for the predilection of Cn to cause CNS infection. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

The Cryptococcus neoformans Transcriptome at the Site of Human Meningitis

PubMed Central

Chen, Yuan; Toffaletti, Dena L.; Tenor, Jennifer L.; Litvintseva, Anastasia P.; Fang, Charles; Mitchell, Thomas G.; McDonald, Tami R.; Nielsen, Kirsten; Boulware, David R.; Bicanic, Tihana; Perfect, John R.

2014-01-01

ABSTRACT Cryptococcus neoformans is the leading cause of fungal meningitis worldwide. Previous studies have characterized the cryptococcal transcriptome under various stress conditions, but a comprehensive profile of the C. neoformans transcriptome in the human host has not been attempted. Here, we extracted RNA from yeast cells taken directly from the cerebrospinal fluid (CSF) of two AIDS patients with cryptococcal meningitis prior to antifungal therapy. The patients were infected with strains of C. neoformans var. grubii of molecular type VNI and VNII. Using RNA-seq, we compared the transcriptional profiles of these strains under three environmental conditions (in vivo CSF, ex vivo CSF, and yeast extract-peptone-dextrose [YPD]). Although we identified a number of differentially expressed genes, single nucleotide variants, and novel genes that were unique to each strain, the overall expression patterns of the two strains were similar under the same environmental conditions. Specifically, yeast cells obtained directly from each patient’s CSF were more metabolically active than cells that were incubated ex vivo in CSF. Compared with growth in YPD, some genes were identified as significantly upregulated in both in vivo and ex vivo CSF, and they were associated with genes previously recognized for contributing to pathogenicity. For example, genes with known stress response functions, such as RIM101, ENA1, and CFO1, were regulated similarly in the two clinical strains. Conversely, many genes that were differentially regulated between the two strains appeared to be transporters. These findings establish a platform for further studies of how this yeast survives and produces disease. PMID:24496797

First report of two cases of cryptococcosis in Tripoli, Libya, infected with Cryptococcus neoformans isolates present in the urban area.

PubMed

Ellabib, M S; Krema, Z A; Allafi, A A; Cogliati, M

2017-09-01

Cryptococcosis is a potentially fatal fungal disease caused by the basidiomycetes yeasts Cryptococcus neoformans and C. gattii with high predilection to invade the central nervous system mainly in immunocompromised hosts. Skin can be secondarily involved in disseminated infection or be exceptionally involved as primary cutaneous infection by inoculation with contaminated materials. We report the first two Libyan cases of cryptococcal meningitis in HIV patients, in which one of them presented a secondary cutaneous involvement due to systemic dissemination. The first patient was a 17-year-old female, had fever, cough, headache and intractable vomiting as well as itchy water bumps on her skin and upper limbs. The cutaneous eruption prompted the accurate diagnosis. Cultures were positive for C. neoformans in both cerebrospinal fluid and skin specimens, as well as cryptococcal antigen was detected in serum. The isolate was identified, by molecular analysis, as C. neoformans AD-hybrid belonging to molecular type VNIII and mating type αAAα, the same genotype found for some environmental isolates recovered from olive trees in Tripoli. The second patient was a 36-years-old male with a long history of HIV on irregular treatment. Cryptococcal antigen in serum was positive and cultures yielded the growth of C. neoformans var. grubii, molecular type VNI and mating type αA. Both patients did not respond adequately to treatment and died of impaired central nervous system function and respiratory failure, respectively. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Cryptococcus gattii in North American Pacific Northwest: Whole-Population Genome Analysis Provides Insights into Species Evolution and Dispersal

PubMed Central

Engelthaler, David M.; Hicks, Nathan D.; Gillece, John D.; Roe, Chandler C.; Schupp, James M.; Driebe, Elizabeth M.; Gilgado, Felix; Carriconde, Fabian; Trilles, Luciana; Firacative, Carolina; Ngamskulrungroj, Popchai; Castañeda, Elizabeth; Lazera, Marcia dos Santos; Melhem, Marcia S. C.; Pérez-Bercoff, Åsa; Huttley, Gavin; Sorrell, Tania C.; Voelz, Kerstin; May, Robin C.; Fisher, Matthew C.; Thompson, George R.; Lockhart, Shawn R.

2014-01-01

ABSTRACT The emergence of distinct populations of Cryptococcus gattii in the temperate North American Pacific Northwest (PNW) was surprising, as this species was previously thought to be confined to tropical and semitropical regions. Beyond a new habitat niche, the dominant emergent population displayed increased virulence and caused primary pulmonary disease, as opposed to the predominantly neurologic disease seen previously elsewhere. Whole-genome sequencing was performed on 118 C. gattii isolates, including the PNW subtypes and the global diversity of molecular type VGII, to better ascertain the natural source and genomic adaptations leading to the emergence of infection in the PNW. Overall, the VGII population was highly diverse, demonstrating large numbers of mutational and recombinational events; however, the three dominant subtypes from the PNW were of low diversity and were completely clonal. Although strains of VGII were found on at least five continents, all genetic subpopulations were represented or were most closely related to strains from South America. The phylogenetic data are consistent with multiple dispersal events from South America to North America and elsewhere. Numerous gene content differences were identified between the emergent clones and other VGII lineages, including genes potentially related to habitat adaptation, virulence, and pathology. Evidence was also found for possible gene introgression from Cryptococcus neoformans var. grubii that is rarely seen in global C. gattii but that was present in all PNW populations. These findings provide greater understanding of C. gattii evolution in North America and support extensive evolution in, and dispersal from, South America. PMID:25028429

Light parameters influence cell viability in antifungal photodynamic therapy in a fluence and rate fluence-dependent manner

NASA Astrophysics Data System (ADS)

Prates, Renato A.; da Silva, Eriques G.; Yamada, Aécio M.; Suzuki, Luis C.; Paula, Claudete R.; Ribeiro, Martha S.

2009-05-01

The aim of this study was to investigate the influence of light parameters on yeast cells. It has been proposed for many years that photodynamic therapy (PDT) can inactivate microbial cells. A number of photosensitizer and light sources were reported in different light parameters and in a range of dye concentrations. However, much more knowledge concerning the importance of fluence, fluence rate and exposure time are required for a better understanding of the photodynamic efficiency. Suspensions (106 CFU/mL) of Candida albicans, Candida krusei, and Cryptococcus neoformans var. grubii were used. Two fluence rates, 100 and 300 mW/cm2 were compared at 3, 6, and 9 min of irradiation, resulting fluences from 18 to 162 J/cm2. The light source was a laser emitting at λ = 660 nm with output power adjusted at 30 and 90 mW. As photosensitizer, one hundred-μM methylene blue was used. Temperature was monitored to verify possible heat effect and reactive oxygen species (ROS) formation was evaluated. The same fluence in different fluence rates showed dissimilar levels of inactivation on yeast cells as well as in ROS formation. In addition, the increase of the fluence rate showed an improvement on cell photoinactivation. PDT was efficient against yeast cells (6 log reduction), and no significant temperature increase was observed. Fluence per se should not be used as an isolate parameter to compare photoinactivation effects on yeast cells. The higher fluence rate was more effective than the lower one. Furthermore, an adequate duration of light exposure cannot be discarded.

Synergy and antagonism between iron chelators and antifungal drugs in Cryptococcus.

PubMed

Lai, Yu-Wen; Campbell, Leona T; Wilkins, Marc R; Pang, Chi Nam Ignatius; Chen, Sharon; Carter, Dee A

2016-10-01

Fungal infections remain very difficult to treat, and developing new antifungal drugs is difficult and expensive. Recent approaches therefore seek to augment existing antifungals with synergistic agents that can lower the therapeutic dose, increase efficacy and prevent resistance from developing. Iron limitation can inhibit microbial growth, and iron chelators have been employed to treat fungal infections. In this study, chequerboard testing was used to explore combinations of iron chelators with antifungal agents against pathogenic Cryptococcus spp. with the aim of determining how disruption to iron homeostasis affects antifungal susceptibility. The iron chelators ethylenediaminetetraacetic acid (EDTA), deferoxamine (DFO), deferiprone (DFP), deferasirox (DSX), ciclopirox olamine and lactoferrin (LF) were paired with the antifungal agents amphotericin B (AmB), fluconazole, itraconazole, voriconazole and caspofungin. All chelators except for DFO increased the efficacy of AmB, and significant synergy was seen between AmB and LF for all Cryptococcus strains. Addition of exogenous iron rescued cells from the antifungal effect of LF alone but could not prevent inhibition by AmB + LF, indicating that synergy was not due primarily to iron chelation but to other properties of LF that were potentiated in the presence of AmB. Significant synergy was not seen consistently for other antifungal-chelator combinations, and EDTA, DSX and DFP antagonised the activity of azole drugs in strains of Cryptococcus neoformans var. grubii. This study highlights the range of interactions that can be induced by chelators and indicates that most antifungal drugs are not enhanced by iron limitation in Cryptococcus. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Anti-cryptococcal activity of ethanol crude extract and hexane fraction from Ocimum basilicum var. Maria bonita: mechanisms of action and synergism with amphotericin B and Ocimum basilicum essential oil.

PubMed

Cardoso, Nathalia N R; Alviano, Celuta S; Blank, Arie F; Arrigoni-Blank, Maria de Fátima; Romanos, Maria Teresa V; Cunha, Marcel M L; da Silva, Antonio Jorge R; Alviano, Daniela S

2017-12-01

Ocimum basilicum L. (Lamiaceae) has been used in folk medicine to treat headaches, kidney disorders, and intestinal worms. This study evaluates the anti-cryptococcal activity of ethanol crude extract and hexane fraction obtained from O. basilicum var. Maria Bonita leaves. The MIC values for Cryptococcus sp. were obtained according to Clinical and Laboratory Standards Institute in a range of 0.3-2500 μg/mL. The checkerboard assay evaluated the association of the substances tested (in a range of 0.099-2500 μg/mL) with amphotericin B and O. basilicum essential oil for 48 h. The ethanol extract, hexane fraction and associations in a range of 0.3-2500 μg/mL were tested for pigmentation inhibition after 7 days of treatment. The inhibition of ergosterol synthesis and reduction of capsule size were evaluated after the treatment with ethanol extract (312 μg/mL), hexane fraction (78 μg/mL) and the combinations of essential oil + ethanol extract (78 μg/mL + 19.5 μg/mL, respectively) and essential oil + hexane fraction (39.36 μg/mL + 10 μg/mL, respectively) for 24 and 48 h, respectively. The hexane fraction presented better results than the ethanol extract, with a low MIC (156 μg/mL against C. neoformans T 444 and 312 μg/mL against C. neoformans H99 serotype A and C. gattii WM779 serotype C). The combination of the ethanol extract and hexane fraction with amphotericin B and essential oil enhanced their antifungal activity, reducing the concentration of each substance needed to kill 100% of the inoculum. The substances tested were able to reduce the pigmentation, capsule size and ergosterol synthesis, which suggest they have important mechanisms of action. These results provide further support for the use of ethanol extracts of O. basilicum as a potential source of antifungal agents.

Seroprevalence of paramyxoviruses in synanthropic and semi-free-range birds.

PubMed

Esperón, Fernando; Vázquez, Belén; Sánchez, Azucena; Fernández-Piñero, Jovita; Yuste, María; Neves, Elena; Nogal, Verónica; Muñoz, María Jesús

2014-06-01

Avian paramyxoviruses (APMVs) are classified into nine different serotypes (APMV 1-9). Virulent strains of APMV-1 are already well characterized as the etiologic agent of Newcastle disease (ND), an important disease in poultry that is potentially capable of infecting all orders of avian species. However, very little is known about the other eight serotypes, the majority of which can cause disease in domestic birds. The role of synanthropic and semi-free-range birds as reservoirs of avian paramyxoviruses is not well understood and the main objective of this work was to evaluate the seroprevalence of APMV 1-9 in these kind of birds. A total of 296 sera, oropharyngeal swabs, and cloacal enemas were collected from semi-free-range birds belonging to four different species: feral pigeons (Columba livia var. domestica), hybrid ducks (Anas sp.), domestic geese (Anser anser domesticus), and white storks (Ciconia ciconia). Antibodies against NDV were found in 56.3% of domestic geese, 42.9% of feral pigeons, and 30.4% of hybrid ducks. Antibodies for other APMVs (-3, -4, -6, -7, -8, -9) were also found. Seven positive individuals were positive to real-time RT-PCR detection, all of them feral pigeons captured in 2006 and 2007. The results obtained reinforce the idea that semi-free-range birds may be good sentinels for the detection of NDV and other avian paramyxoviruses.

E-NTPDase and E-ADA activities in rats experimental infected by Cryptococcus neoformans.

PubMed

de Azevedo, Maria Isabel; Ferreiro, Laerte; Da Silva, Aleksandro S; Tonin, Alexandre A; Ruchel, Jader B; Rezer, João F P; França, Raqueli T; Zimmermann, Carine E P; Leal, Daniela B R; Duarte, Marta M M F; Lopes, Sonia T A; Flores, Mariana M; Fighera, Rafael; Santurio, Janio M

2014-11-07

Cryptococcus neoformans, the etiological agent of cryptococcosis, is an opportunistic fungal pathogen of immunocompromised individuals. The aim of this study was to evaluate the activities of E-NTPDase and E-ADA in rats experimentally infected by C. neoformans var. grubii. Adult rats (35) were divided in two groups: 18 for the control group (uninfected) (A), and 17 for the infected group (B). Each group was separated into three sub-groups (A1, A2, A3-B1, B2, B3), and samples were collected on 10, 20, and 30 days post-infection (PI). Leukocyte counts, IFN-γ, TNF-α, IgM, IgG levels, and E-NTPDase and E-ADA activities were analyzed. It was possible to observe that IgG and IgM seric levels of infected rats were significantly elevated (P<0.01) on days 10, 20 and 30 PI, as well as the levels of TNF-α and INF-γ when compared to uninfected rodents. Regarding E-NTPDase activity in lymphocytes, it was possible to observe that the ATP hydrolysis was significantly decreased on days 20 (P<0.01) and 30 PI (P<0.05), while ADP hydrolysis was significantly reduced only on day 20 PI (P<0.01) when compared with uninfected group. Seric E-ADA activity had a significant reduction (P<0.01) during all three evaluated periods when compared to the control group, while E-ADA activity in lymphocytes increased significantly (P<0.01) when compared to the group A on day 10 PI; however on days 20 and 30 PI, its activity was considerable reduced in lymphocytes of infected animals (P<0.01). Therefore, it is possible to conclude that the infection caused by C. neoformans in immunocompetent rats leads to changes in the purinergic signaling (NTPDase and E-ADA), concomitantly with an inflammatory response (increased levels of cytokines and immunoglobulins) associated with inflammatory infiltrates and histological lesions in the lung. Copyright © 2014 Elsevier B.V. All rights reserved.

Use of enrichment real-time PCR to enumerate salmonella on chicken parts.

PubMed

Oscar, T P

2014-07-01

Salmonella bacteria that survive cooking or that cross-contaminate other food during meal preparation and serving represent primary routes of consumer exposure to this pathogen from chicken. In the present study, enrichment real-time PCR (qPCR) was used to enumerate Salmonella bacteria that contaminate raw chicken parts at retail or that cross-contaminate cooked chicken during simulated meal preparation and serving. Whole raw chickens obtained at retail were partitioned into wings, breasts, thighs, and drumsticks using a sterilized knife and cutting board, which were then used to partition a cooked chicken breast to assess cross-contamination. After enrichment in buffered peptone water (400 ml, 8 h, 40°C, 80 rpm), subsamples were used for qPCR and cultural isolation of Salmonella. In some experiments, chicken parts were spiked with 0 to 3.6 log of Salmonella Typhimurium var. 5- to generate a standard curve for enumeration by qPCR. Of 10 raw chickens examined, 7 (70%) had one or more parts contaminated with Salmonella. Of 80 raw parts examined, 15 (19%) were contaminated with Salmonella. Of 20 cooked chicken parts examined, 2 (10%) were cross-contaminated with Salmonella. Predominant serotypes identified were Typhimurium (71%) and its variants (var. 5-, monophasic, and nonmotile) and Kentucky (18%). The number of Salmonella bacteria on contaminated parts ranged from one to two per part. Results of this study indicated that retail chicken parts examined were contaminated with low levels of Salmonella, which resulted in low levels of cross-contamination during simulated meal preparation and serving. Thus, if consumers properly handle and prepare the chicken, it should pose no or very low risk of consumer exposure to Salmonella.

Analysis of loci required for determination of serotype antigenicity in Streptococcus mutans and its clinical utilization.

PubMed

Shibata, Yukie; Ozaki, Kazuhisa; Seki, Mitsuko; Kawato, Takayuki; Tanaka, Hideki; Nakano, Yoshio; Yamashita, Yoshihisa

2003-09-01

We recently identified the genes responsible for the serotype c-specific glucose side chain formation of rhamnose-glucose polysaccharide (RGP) in Streptococcus mutans. These genes were located downstream from the rgpA through rgpF locus that is involved in the synthesis of RGP. In the present study, the corresponding chromosomal regions were isolated from serotype e and f strains and characterized. The rgpA through rgpF homologs were well conserved among the three serotypes. By contrast, the regions downstream from the rgpF homolog differed considerably among the three serotypes. Replacement of these regions in the different serotype strains converted their serotypic phenotypes, suggesting that these regions participated in serotype-specific glucose side chain formation in each serotype strain. Based on the differences among the DNA sequences of these regions, a PCR method was developed to determine serotypes. S. mutans was isolated from 198 of 432 preschool children (3 to 4 years old). The serotypes of all but one S. mutans isolate were identified by serotyping PCR. Serotype c predominated (84.8%), serotype e was the next most common (13.3%), and serotype f occured rarely (1.9%) in Japanese preschool children. Caries experience in the group with a mixed infection by multiple serotypes of S. mutans was significantly higher than that in the group with a monoinfection by a single serotype.

Serotyping of Streptococcus pneumoniae Based on Capsular Genes Polymorphisms

PubMed Central

Raymond, Frédéric; Boucher, Nancy; Allary, Robin; Robitaille, Lynda; Lefebvre, Brigitte; Tremblay, Cécile

2013-01-01

Streptococcus pneumoniae serotype epidemiology is essential since serotype replacement is a concern when introducing new polysaccharide-conjugate vaccines. A novel PCR-based automated microarray assay was developed to assist in the tracking of the serotypes. Autolysin, pneumolysin and eight genes located in the capsular operon were amplified using multiplex PCR. This step was followed by a tagged fluorescent primer extension step targeting serotype-specific polymorphisms. The tagged primers were then hybridized to a microarray. Results were exported to an expert system to identify capsular serotypes. The assay was validated on 166 cultured S. pneumoniae samples from 63 different serotypes as determined by the Quellung method. We show that typing only 12 polymorphisms located in the capsular operon allows the identification at the serotype level of 22 serotypes and the assignation of 24 other serotypes to a subgroup of serotypes. Overall, 126 samples (75.9%) were correctly serotyped, 14 were assigned to a member of the same serogroup, 8 rare serotypes were erroneously serotyped, and 18 gave negative serotyping results. Most of the discrepancies involved rare serotypes or serotypes that are difficult to discriminate using a DNA-based approach, for example 6A and 6B. The assay was also tested on clinical specimens including 43 cerebrospinal fluid samples from patients with meningitis and 59 nasopharyngeal aspirates from bacterial pneumonia patients. Overall, 89% of specimens positive for pneumolysin were serotyped, demonstrating that this method does not require culture to serotype clinical specimens. The assay showed no cross-reactivity for 24 relevant bacterial species found in these types of samples. The limit of detection for serotyping and S. pneumoniae detection was 100 genome equivalent per reaction. This automated assay is amenable to clinical testing and does not require any culturing of the samples. The assay will be useful for the evaluation of serotype prevalence changes after new conjugate vaccines introduction. PMID:24086706

Characterization of Chinese Haemophilus parasuis Isolates by Traditional Serotyping and Molecular Serotyping Methods

PubMed Central

Ma, Lina; Wang, Liyan; Chu, Yuefeng; Li, Xuerui; Cui, Yujun; Chen, Shengli; Zhou, Jianhua; Li, Chunling; Lu, Zhongxin; Liu, Jixing; Liu, Yongsheng

2016-01-01

Haemophilus parasuis is classified mainly through serotyping, but traditional serotyping always yields non-typable (NT) strains and unreliable results via cross-reactions. Here, we surveyed the serotype prevalence of Chinese H. parasuis isolates using traditional serotyping (gel immuno-diffusion test, GID) and molecular serotyping (multiplex PCR, mPCR). We also investigated why discrepant results between these methods were obtained, and investigated mPCR failure through whole-genome sequencing. Of the 100 isolate tested, 73 (73%) and 93 (93%) were serotyped by the GID test and mPCR, respectively, with a concordance rate of 66% (66/100). Additionally, mPCR reduced the number of NT isolates from 27 (27%) for the GID testing, to seven (7%). Eleven isolates were sequenced, including nine serotype-discrepant isolates from mPCR and GID typing (excluding strains that were NT by GID only) and two NT isolates from both methods, and their in silico serotypes were obtained from genome sequencing based on their capsule loci. The mPCR results were supported by the in silico serotyping of the seven serotype-discrepant isolates. The discrepant results and NT isolates determined by mPCR were attributed to deletions and unknown sequences in the serotype-specific region of each capsule locus. Compared with previous investigations, this study found a similar predominant serotype profile, but a different prevalence frequency for H. parasuis, and the five most prevalent serotypes or strain groups were serotypes 5, 4, NT, 7 and 13 for mPCR, and serotypes 5, NT, 4, 7 and 13/10/14 for GID. Additionally, serotype 7 was recognized as a principal serotype in this work. PMID:28005999

Chromosome numbers of populations of three varieties of Bidens pilosa in Taiwan.

PubMed

Huang, Ya-Lun; Kao, Wen-Yuan

2015-12-01

Hairy beggar-ticks (Bidens pilosa L.) is a common invasive plant in tropical and subtropical regions. The Flora of Taiwan listed three varieties of B. pilosa in Taiwan, var. minor, var. pilosa and var. radiata. Among the three varieties, var. radiata was the most recently, in 1970s, introduced into Taiwan. However, after its introduction into Taiwan, var. radiata has become dominant over the other two varieties and is considered a serious invasive plant in lowland of Taiwan. Our previous study showed that var. radiata is self-incompatible and the other two varieties are self-fertile. Could it be possible that different chromosome numbers contribute to the different breeding systems of these three varieties? In addition, the heterogeneities of traits of var. radiata were found higher than those of var. minor and var. pilosa. Is the phenomenon resulting from the hybridization between var. radiata with other varieties? We counted chromosome numbers of populations of these three varieties distributed in Taiwan and conducted hand pollination treatment between var. radiata (as pollen receiver) and var. minor or var. pilosa (as pollen donor) to provide answer for the aforementioned questions. No difference was found in chromosome numbers among populations of the same variety. Forty-eight chromosomes (2n = 48) were counted for var. radiata while 72 (2n = 72) chromosomes for var. minor and var. pilosa. Therefore, var. radiata is tetraploid and var. minor and var. pilosa are hexaploid. No successful hybridization was found between var. radiata and var. minor or between var. radiata and var. pilosa. This study provided the evidence that the invasive plant (B. pilosa var. radiata) has different chromosome numbers from the other two varieties and is unlikely to hybridize with the other two varieties.

Molecular analysis of the genes involved in the biosynthesis of serotype specific polysaccharide in the novel serotype k strains of Streptococcus mutans.

PubMed

Nomura, R; Nakano, K; Ooshima, T

2005-10-01

We previously reported the new serotype k of Streptococcus mutans, which, compared to serotypes c, e, and f, features a drastic reduction in the length of the glucose side chain linked to the rhamnose backbone of the serotype specific polysaccharide. The 5' region of the rgpF gene of serotype k strains contains a distinctive nucleotide sequence, which suggests that an alteration of the rgpF gene in serotype k strains may explain the shortened glucose side chain. However, in the present study, expression of the rgpF gene of MT8148 (serotype c) in serotype k isolates was not found to lead to serotype conversion. Furthermore, mRNA expression of rgpE, known to be associated with glucose side chain formation, was not detected in any of the tested serotype k isolates with an RT-PCR method. The nucleotide alignment of all genes known to be involved in the biosynthesis of serotype specific polysaccharide in serotype k strains was shown to be quite similar to that of serotype c strains, as compared to serotype e and f strains, especially in the region downstream of rgpF. Our results indicate that the common characteristics of serotype k isolates may be caused by a lack of expression of the gene involved in glucose side chain formation.

Age-Specific Cluster of Cases of Serotype 1 Streptococcus pneumoniae Carriage in Remote Indigenous Communities in Australia ▿

PubMed Central

Smith-Vaughan, H.; Marsh, R.; Mackenzie, G.; Fisher, J.; Morris, P. S.; Hare, K.; McCallum, G.; Binks, M.; Murphy, D.; Lum, G.; Cook, H.; Krause, V.; Jacups, S.; Leach, A. J.

2009-01-01

Seven-valent pneumococcal conjugate vaccination commenced in 2001 for Australian indigenous infants. Pneumococcal carriage surveillance detected substantial replacement with nonvaccine serotypes and a cluster of serotype 1 carriage. Our aim was to review Streptococcus pneumoniae serotype 1 carriage and invasive pneumococcal disease (IPD) data for this population and to analyze serotype 1 isolates. Carriage data were collected between 1992 and 2004 in the Darwin region, one of the five regions in the Northern Territory. Carriage data were also collected in 2003 and 2005 from four regions in the Northern Territory. Twenty-six cases of serotype 1 IPD were reported from 1994 to 2007 in the Northern Territory. Forty-four isolates were analyzed by BOX typing and 11 by multilocus sequence typing. In the Darwin region, 26 children were reported carrying serotype 1 (ST227) in 2002 but not during later surveillance. Scattered cases of serotype 1 carriage were noted in two other regions. Cocolonization of serotype 1 with other pneumococcal serotypes was common (34% serotype 1-positive swabs). In conclusion, pneumococcal carriage studies detected intermittent serotype 1 carriage and an ST227 cluster in children in indigenous communities in the Northern Territory of Australia. There was no apparent increase in serotype 1 IPD during this time. The rate of serotype 1 cocolonization with other pneumococcal serotypes suggests that carriage of this serotype may be underestimated. PMID:19091995

Comparison of Capsular Genes of Streptococcus pneumoniae Serotype 6A, 6B, 6C, and 6D Isolates▿

PubMed Central

Song, Jae-Hoon; Baek, Jin Yang; Ko, Kwan Soo

2011-01-01

Recently, Streptococcus pneumoniae serotypes 6C and 6D have been identified. It is thought that they emerged by the replacement of wciNβ in the capsular loci of serotypes 6A and 6B, respectively. However, their evolution has not been unveiled yet. To investigate the evolution of four serotypes of S. pneumoniae serogroup 6, four genes of the capsular polysaccharide synthesis (cps) locus, wchA, wciN, wciO, and wciP, of isolates of S. pneumoniae serotypes 6A, 6B, 6C, and 6D were sequenced. Multilocus sequence typing (MLST) was performed to investigate their genetic backgrounds. The wchA gene of serotype 6C and 6D isolates was distinct from that of serotype 6A and 6B isolates, which may suggest cotransfer of wchA with wciNβ. Otherwise, serotypes 6C and 6D displayed different genetic backgrounds from serotypes 6A and 6B, which was suggested by MLST analysis. In addition, serotype 6C isolates showed distinct wciP polymorphisms from other serotypes, which also indicated that serotype 6C had not recently originated from serotype 6A. Although serotype 6D shared the same amino acid polymorphisms of wciO with serotype 6B, wciP of serotype 6D differed from that of serotype 6B. The data indicate the implausibility of the scenario of a recent emergence of the cps locus of serotype 6D by genetic recombination between serotypes 6B and 6C. In addition, five serotype 6A and 6B isolates (6X group) displayed cps loci distinct from those of other isolates. The cps locus homogeneity and similar sequence types in MLST analysis suggest that most of the 6X group of isolates originated from the same ancestor and that the entire cps locus might have recently been transferred from an unknown origin. Serotype 6B isolates showed two or more cps locus subtypes, indicating a recombination-mediated mosaic structure of the cps locus of serotype 6B. The collective data favor the emergence of cps loci of serotypes 6A, 6B, 6C, and 6D by complicated recombination. PMID:21411593

Rapid Multiplex Assay for Serotyping Pneumococci with Monoclonal and Polyclonal Antibodies

PubMed Central

Yu, Jigui; Lin, Jisheng; Benjamin, William H.; Waites, Ken B.; Lee, Che-hung; Nahm, Moon H.

2005-01-01

We have developed and characterized a rapid semiautomated pneumococcal serotyping system incorporating a pneumococcal lysate preparation protocol and a multiplex serotyping assay. The lysate preparation incorporates a bile solubility test to confirm pneumococcal identification that also enhances assay specificity. The multiplex serotyping assay consists of 24 assays specific for 36 serotypes: serotypes 1, 2, 3, 4, 5, 6A, 6B, 7A/7F, 8, 9L/9N, 9V, 10A/10B/39/(33C), 11A/11D/11F, 12A/12B/12F, 14, 15B/(15C), 17F, 18C, 19A, 19F, 20, 22A/22F, 23F, and 33A/33F. The multiplex assay requires a flow cytometer, two sets of latex particles coated with pneumococcal polysaccharides, and serotype-specific antibodies. Fourteen newly developed monoclonal antibodies specific for common serotypes and a pool of polyclonal rabbit sera for some of the less-common serotypes are used. The two monoclonal antibodies specific for serotypes 18C and 23F recognize serotype-specific epitopes that have not been previously described. These monoclonal antibodies make the identification of the 14 common serotypes invariant. The specificity of the serotyping assay is fully characterized with pneumococci of all known (i.e., 90) serotypes. The assay is sensitive enough to use bacterial lysates diluted 20 fold. Our serotyping system can identify not only all the serotypes in pneumococcal vaccines but also most (>90%) of clinical isolates. This system should be very useful in serotyping clinical isolates for evaluating pneumococcal vaccine efficacy. PMID:15634965

PCR deduction of invasive and colonizing pneumococcal serotypes from Venezuela: a critical appraisal.

PubMed

Bello Gonzalez, Teresita; Rivera-Olivero, Ismar Alejandra; Sisco, María Carolina; Spadola, Enza; Hermans, Peter W; de Waard, Jacobus H

2014-04-15

Serotype surveillance of Streptococcus pneumoniae is indispensable for evaluating the potential impact of pneumococcal conjugate vaccines. Serotyping by the standard Quellung reaction is technically demanding, time consuming, and expensive. A simple and economical strategy is multiplex PCR-based serotyping. We evaluated the cost effectiveness of a modified serial multiplex PCR (mPCR), resolving 24 serotypes in four PCR reactions and optimally targeting the most prevalent invasive and colonizing pneumococcal serotypes found in Venezuela. A total of 223 pneumococcal isolates, 140 invasive and 83 carriage isolates, previously serotyped by the Quellung reaction and representing the 18 most common serotypes/groups identified in Venezuela, were serotyped with the adapted mPCR. The mPCR serotyped 76% of all the strains in the first two PCR reactions and 91% after four reactions, correctly identifying 17 serotypes/groups. An isolate could be serotyped with mPCR in less than 2 minutes versus 15 minutes for the Quellung reaction, considerably lowering labor costs. A restrictive weakness of mPCR was found for the detection of 19F strains. Most Venezuelan 19F strains were not typeable using the mPCR, and two 19F cps serotype variants were identified. The mPCR assay is an accurate, rapid, and economical method for the identification of the vast majority of the serotypes from Venezuela and can be used in place of the standard Quellung reaction. An exception is the identification of serotype 19F. In this setting, most 19F strains were not detectable with mPCR, demonstrating a need of serology-based quality control for PCR-based serotyping.

[A new zoonosis--investigation of Gardnerella vaginalis disease of fox. V. Studies serotype of Gardnerella vaginalis in fox].

PubMed

Yan, X; Yan, Z; Yan, X; Luan, F; Wang, C

1996-10-01

145 strains Gardnerella vaginalis isolated in foxes were isolated from 13 main farms raising foxes in six provinces (regions), China, after antigenicity and immunogenicity of the strains were measured, 1-3 appropriate strains were selected from each farm raising foxes for serotype studies. Cross agglutinin absorption test confirmed that selected 26 strains Gardnerella vaginalis were divided into three serotypes and then the representing strains were used to produce typing serum. Among remaining 119 strain, 108 strains were typable with the typing sera, and 11 strains can't be set. Among three serotypes, serotype I made up 79.1% of the strains. It was shown that serotype I was the principal serotype of Gardnerella vaginalis of fox in China. The test also confirmed that 5 strains of Gardnerella vaginalis isolated from racoon dog, 4 strain Gardnerella vaginalis from mink and 2 strains Gardnerella vaginalis from canine also belonged to serotype I. Supersonic antigben was produced with three serotypes, representative strains. By agar immuno-diffusion test, it confirmed that the antigens of three serotypes formed a obvious blending precipitating line with the homologous or heterologous serotype antiserum. It indicated common antigen existed among all serotypes. The agar immuno-diffusion test results revealed that the precipitating line of the homologous serotype completely blended. It is our opinion that the method of serotyping is reliable.

A serotype-specific polymerase chain reaction for identification of Pasteurella multocida serotype 1

USGS Publications Warehouse

Rocke, T.E.; Smith, S.R.; Miyamoto, A.; Shadduck, D.J.

2002-01-01

A serotype-specific polymerase chain reaction (PCR) assay was developed for detection and identification of Pasteurella multocida serotype 1, the causative agent of avian cholera in wild waterfowl. Arbitrarily primed PCR was used to detect DNA fragments that distinguish serotype 1 from the other 15 serotypes of P. multocida (with the exception of serotype 14). Oligonucleotide primers were constructed from these sequences, and a PCR assay was optimized and evaluated. PCR reactions consistently resulted in amplification products with reference strains 1 and 14 and all other serotype 1 strains tested, with cell numbers as low as 2.3 cells/ml. No amplification products were produced with other P. multocida serotypes or any other bacterial species tested. To compare the sensitivity and further test the specificity of this PCR assay with traditional culturing and serotyping techniques, tissue samples from 84 Pekin ducks inoculated with field strains of P. multocida and 54 wild lesser snow geese collected during an avian cholera outbreak were provided by other investigators working on avian cholera. PCR was as sensitive (58/64) as routine isolation (52/64) in detecting and identifying P. multocida serotype 1 from the livers of inoculated Pekins that became sick or died from avian cholera. No product was amplified from tissues of 20 other Pekin ducks that received serotypes other than type 1 (serotype 3, 12 × 3, or 10) or 12 control birds. Of the 54 snow geese necropsied and tested for P. multocida, our PCR detected and identified the bacteria from 44 compared with 45 by direct isolation. The serotype-specific PCR we developed was much faster and less labor intensive than traditional culturing and serotyping procedures and could result in diagnosis of serotype 1 pasteurellosis within 24 hr of specimen submission.

Detection of serotype k Streptococcus mutans in Thai subjects.

PubMed

Lapirattanakul, J; Nakano, K; Nomura, R; Nemoto, H; Kojima, A; Senawongse, P; Srisatjaluk, R; Ooshima, T

2009-10-01

Streptococcus mutans, known to be a pathogen of dental caries as well as bacteremia and infective endocarditis, is classified into four serotypes, c, e, f and k, based on the structures of serotype-specific polysaccharides. Serotype k was recently designated using blood isolates from Japanese subjects and such strains are considered to be virulent in the bloodstream. The purpose of the present study was to analyse the serotype distribution of strains isolated from Thai subjects and determine whether serotype k strains were present. A total of 250 S. mutans strains were isolated from 50 Thai subjects, and serotypes of all strains were determined. Then, molecular and biological analyses were carried out for serotype k strains. Immunodiffusion and polymerase chain reaction analyses showed that serotype c was the most prevalent (70%), followed by serotypes e (22.8%), f (4.4%) and k (2.8%), which indicated that serotype k S. mutans strains occurred in Thai individuals at a similar rate to that previously reported for Japanese and Finnish populations. Molecular analyses of the seven serotype k strains showed extremely low expression of rgpE, which is related to glucose side-chain formation in serotype-specific rhamnose-glucose polymers, similar to previous reports for those other populations. In addition, analysis of the biological properties of the seven serotype k strains demonstrated low levels of sucrose-dependent adhesion, cellular hydrophobicity, dextran-binding activity and phagocytosis susceptibility by human polymorphonuclear leukocytes, which are characteristics similar to those of serotype k strains previously isolated in Japan. Our results indicate the possibility of a worldwide prevalence of serotype k strains with properties in common with those of previously reported strains.

The Relevance of a Novel Quantitative Assay to Detect up to 40 Major Streptococcus pneumoniae Serotypes Directly in Clinical Nasopharyngeal and Blood Specimens

PubMed Central

Albrich, Werner C.; van der Linden, Mark P. G.; Bénet, Thomas; Chou, Monidarin; Sylla, Mariam; Barreto Costa, Patricia; Richard, Nathalie; Klugman, Keith P.; Endtz, Hubert P.; Paranhos-Baccalà, Gláucia; Telles, Jean-Noël

2016-01-01

For epidemiological and surveillance purposes, it is relevant to monitor the distribution and dynamics of Streptococcus pneumoniae serotypes. Conventional serotyping methods do not provide rapid or quantitative information on serotype loads. Quantitative serotyping may enable prediction of the invasiveness of a specific serotype compared to other serotypes carried. Here, we describe a novel, rapid multiplex real-time PCR assay for identification and quantification of the 40 most prevalent pneumococcal serotypes and the assay impacts in pneumonia specimens from emerging and developing countries. Eleven multiplex PCR to detect 40 serotypes or serogroups were optimized. Quantification was enabled by reference to standard dilutions of known bacterial load. Performance of the assay was evaluated to specifically type and quantify S. pneumoniae in nasopharyngeal and blood samples from adult and pediatric patients hospitalized with pneumonia (n = 664) from five different countries. Serogroup 6 was widely represented in nasopharyngeal specimens from all five cohorts. The most frequent serotypes in the French, South African, and Brazilian cohorts were 1 and 7A/F, 3 and 19F, and 14, respectively. When both samples were available, the serotype in blood was always present as carriage with other serotypes in the nasopharynx. Moreover, the ability of a serotype to invade the bloodstream may be linked to its nasopharyngeal load. The mean nasopharyngeal concentration of the serotypes that moved to the blood was 3 log-fold higher than the ones only found in the nasopharynx. This novel, rapid, quantitative assay may potentially predict some of the S. pneumoniae serotypes invasiveness and assessment of pneumococcal serotype distribution. PMID:26986831

Redistribution of Streptococcus pneumoniae Serotypes After Nationwide 13-valent Pneumococcal Conjugate Vaccine Program in Children in Northern Taiwan.

PubMed

Cho, Ying-Chun; Chiu, Nan-Chang; Lu, Chun-Yi; Huang, Daniel Tsung-Ning; Huang, Fu-Yuan; Chang, Luan-Yin; Huang, Li-Min; Chi, Hsin

2017-12-01

After the introduction of 13-valent pneumococcal conjugate vaccine (PCV13) against Streptococcus pneumoniae, public health officials in Taiwan monitored a decline in circulating vaccine serotypes and the emergence of nonvaccine serotypes in children with invasive pneumococcal disease. A gradually expanded PCV13 national immunization program was launched in 2013 in Taiwan. Here, we evaluate the changes in the distribution of pneumococcal serotypes and antimicrobial nonsusceptibility in children during the evolution of vaccination policy. S. pneumoniae isolates from children with pneumococcal disease were collected and serotyped from 2010 to 2015 in northern Taiwan. PCVs were administered at the recipients' expense between 2010 and 2012, and then PCV13 was partially reimbursed by the government beginning in 2013. The distribution and diversity of serotypes were analyzed along with their antimicrobial susceptibilities. Among a total of 498 isolates, the proportion of invasive pneumococcal disease isolates declined (47.1%-10.6%) during the study period, and serotype diversity increased after 2011. Between 2010 and 2012, the dominant serotypes were 19A, 19F, 3, 6B and 14, and serotype 19A rose from 44.1% to 57.5%. Serotypes 19A, 15A, 19F and 15B were more prevalent from 2013 to 2015, and serotype 19A decreased from 42.1% to 4.5%. Serotypes 19F and 15A became the most commonly detected serotypes in 2015. Overall, PCV13 additional serotypes were reduced by 80% (P < 0.0001) but nonvaccine serotypes increased from 8.8% to 51.5% (P < 0.0001). The step-by-step PCV13 national immunization program is effective against pneumococcal disease in Taiwanese children, mainly by reducing PCV13 additional serotypes.

Spatial pattern of foot-and-mouth disease virus serotypes in North Central Nigeria

PubMed Central

Wungak, Yiltawe Simwal; Ishola, Olayinka O.; Olugasa, Babasola O.; Lazarus, David D.; Ehizibolo, David O.; Ularamu, Hussaini G.

2017-01-01

Aim: This study aimed to determine the foot-and-mouth disease virus (FMDV) serotypes circulating, the prevalence of FMDV serotypes, and the spatial distribution of FMDV among sedentary and pastoral cattle herds in the North-Central Nigeria. Materials and Methods: A cross-sectional study was undertaken, during which a total of 155 sera that tested positive for foot-and-mouth disease (FMD) 3ABC non-structural protein antibodies were selected and screened for FMD structural protein serotypes, A, O, SAT 1, and SAT 2 using a solid-phase competitive enzyme-linked immunosorbent assay (ELISA). Epithelial tissue specimens were collected during outbreak investigations which were tested for FMD using an antigen capture ELISA for serotype A, O, SAT 1, and SAT 2. Results: An overall serotype-specific prevalence of 79.35 (95% confidence interval [CI]: 72.4-85.18) was recorded for serotype O, 65.2% (95% CI: 57.41-72.3) for serotype A, 52.9% (95% CI: 45.03-60.67) for SAT 2, and 33.55% (95% CI: 26.45-41.26) for SAT 1. Evidence of exposure to multiple FMDV serotypes showed that 12.26% of the sera samples had antibodies against four serotypes circulating, 30.97% had antibodies against three serotypes circulating, 22.58% had antibodies against two serotypes, and 17% showed exposure to only one serotype. Clinical specimens (epithelial tissue) collected during outbreak investigations showed that serotype O has the highest proportion of 50% with serotype A - 25%; SAT 2 - 20.8%; and SAT 1 - 4.1%. Conclusion: The study detected diffuse and co-circulation of serotypes A, O, SAT 1, and SAT 2 within the study area, and hence the need for the appropriately matched multivalent vaccine is strongly advocated for FMD control in Nigeria. PMID:28507418

Around the World in 1,475 Salmonella Geo-serotypes

PubMed Central

Le Hello, Simon; de Jong, Birgitta; Rolfhamre, Per; Faensen, Daniel; Weill, François-Xavier; Giesecke, Johan

2016-01-01

It’s easy to remember Salmonella serotypes names, isn’t it? Surely, this is because the naming system of Salmonella serotypes is by far the most scientist friendly. Traditionally, most Salmonella serotypes have been named after geographic locations. We decided to explore the geographic locations to which Salmonella serotypes refer and describe some unexpected twists in the naming scheme. We found that 93% (n = 1,475) of the 1,585 serotypes could be categorized as geo-serotypes; that is, the name refers to a geographic location. The 3 countries with the most geo-serotypes are Germany, the United Kingdom, and the United States. Other serotype names refer to the name of a person, animal, tribe, or food item or are a composite of symptoms and host. The Salmonella serotypes naming scheme has had a valuable effect on public health microbiology, and in the current era of fast development of whole-genome sequencing, it should remain a reference.

Novel PCR-Restriction Fragment Length Polymorphism Method for Determining Serotypes or Serogroups of Streptococcus pneumoniae Isolates

PubMed Central

Batt, Sarah L.; Charalambous, Bambos M.; McHugh, Timothy D.; Martin, Siobhan; Gillespie, Stephen H.

2005-01-01

Serotyping Streptococcus pneumoniae is a technique generally confined to reference laboratories, as purchasing pneumococcal antisera is a huge investment. Many attempts have been made to modify serological agglutination techniques to make them more accessible, and more recently developments in serotyping have focused on molecular techniques. This paper describes a PCR assay which amplifies the entire capsulation locus between dexB and aliA. Amplicons are digested to produce serotype-specific patterns. We have shown, using 81 epidemiologically unrelated strains representing 46 different serotypes, that the patterns correlate with a 90 to 100% similarity range for the same serotype or serogroup. Prospective testing of 73 isolates of unknown serotype confirmed reliable serotype attribution, and serotype profiles are reproducible on repeated testing. Once our database contains all 90 serotypes, this technique should be fully portable, cost-effective, and useful in any laboratory with sufficient molecular experience. PMID:15956380

Serotypes of Streptococcus suis isolated from healthy pigs in Phayao Province, Thailand.

PubMed

Thongkamkoon, P; Kiatyingangsulee, T; Gottschalk, M

2017-01-19

Streptococcus suis (S. suis) is an important swine and human pathogen. There are 33 serotypes that have been described. Zoonotic cases are very common the Northern part of Thailand, especially in Phayao Province. However, the prevalence of S. suis and, more particularly the different serotypes, in pigs in this region is poorly known and needed to be addressed. Distribution of S. suis serotypes varies depending on the geographical area. Knowledge of the serotype distribution is important for epidemiological studies. Consequently, 180 tonsil samples from slaughterhouse pigs in Phayao Province had been collected for surveillance, from which 196 S. suis isolates were recovered. Each isolate was subcultured and its serotype identified using multiplex PCR. Slide agglutination combined with precipitation tests were used following multiplex PCR to differentiate the isolates showing similar sizes of amplified products specific to either serotype 1 or 14 and 2 or 1/2. Non-typable isolates by multiplex PCR were serotyped by the coagglutination test. Of the 196 isolates, 123 (62.8%) were typable and 73 (37.2%) were non-typable. This study revealed the presence of serotypes 1, 1/2, 2, 3, 4, 5, 7, 9, 11, 12, 13, 14, 21, 22, 23, 24, 25, 29, and 30. Serotype 23 was the most prevalent (20/196, 10.2%), followed by serotype 9 (16/196, 8.2%), serotype 7 (16/196, 8.2%), and serotype 2 (11/196, 5.6%). The latter is the serotype responsible for most human cases. Almost all serotypes previously described are present in Northern Thailand. Therefore, this report provides useful data for future bacteriological studies.

Effects of local immunization with glucosyltransferase fractions from Streptococcus mutans on dental caries in hamsters caused by homologous and heterologous serotypes of Streptococcus mutans.

PubMed

Smith, D J; Taubman, M A; Ebersole, J L

1978-09-01

Seven serotypes of Streptococcus mutans have been identified. The biochemical, genetic, and serological characteristics of these serotypes have indicated that certain serotypes are quite similar, whereas others are quite distinct. The effect of local immunization with glucosyltransferase (GTF) enzymes from serotypes a, c, or g on infection and disease caused by homologous or heterologous cariogenic S. mutans is reported. Organisms with either similar (a and g) or different (c and g) biochemical and serological characteristics were selected for heterologous challenge. NIH white hamsters were injected four times at weekly intervals with GTF prepared by 6 M guanidine-hydrochloride elution from water-insoluble glucan of serotypes a, c, or g, which resulted in enzyme (homologous) inhibitory activity in sera and salivas. After infection of GTF-immunized and sham-immunized groups of hamsters with cariogenic S. mutans of the same serotype as the injected antigen (homologous infection) or with S. mutans of a different serotype from the injected antigen (heterologous infection), the numbers of streptomycin-labeled S. mutans, caries, and lesions were determined. Immunization with GTF preparations from each of the three serotypes resulted in statistically significant reductions in the extent of infection and disease and number of lesions caused by infections with homologous cariogenic S. mutans. Statistically significant reductions in these three parameters were also observed in groups immunized with enzyme from serotype a (strain E49) and challenged with cariogenic serotype g (strain 6715) organisms; or immunized with enzyme from serotype c (strain Ingbritt) and challenged with cariogenic serotype g (strain 6715) organisms; or immunized with enzyme from serotype g (strain 6715) and challenged with cariogenic serotype c (strain Ingbritt) organisms. These studies suggest that soluble antigen preparations containing GTF from one serotype may elicit a protective immune response against infection with cariogenic S. mutans from many or possibly all serotypes.

Seroprevalence of Chlamydia trachomatis types in children with clinical trachoma in New Delhi, India.

PubMed

Kumar, V N; Sujata, M; Satpathy, G

1991-01-01

Micro-immunofluorescence test with type specific antigens of ocular Chlamydial infection types A-D was used for serotyping the causative C. trachomatis serotypes in 32 inclusion positive school children suffering from trachoma. Single serotype associated infection was seen in six of the patients. The rest of them had antibodies against more than one serotype indicating simultaneous or previous infection by more than one serotype. By geometric mean titre determination, type C appeared to be the most prevalent serotype. However the highest antibody titres in individual cases were most frequently observed for serotype A. The use of geometric mean titre versus highest titre against specific serotype observed in individual cases for population survey is discussed. Isolation of organism for absolute determination of causative serotype from each patient is emphasised.

Pathogenesis of Salmonellosis: Salmonella Exotoxins

DTIC Science & Technology

1982-03-08

of Salmonella enteritidis , which included 9630 serotype newport, 9136 serotype newport, 10016 serotype javiana, and 8832, serotype javiana were also...supplied by Dr. T. Huber. Additionally, four clinical isolates of Salmonella enteritidis , which included 986 serotype typhimurium, 2000 serotype...77Z7I AD _ REPORT NUMBER 3 0 Pathogenesis of Salmonellosis: Salmonella Exotoxins Annual Progress Report (9/1/79-8/31/80) M Johnny W. Peterson, Ph.D

Establishment and localization of mixtures of Streptococcus mutans serotypes in the oral cavity of the rat.

PubMed

Huis in 't Veld, J H; Drost, J S; Havenaar, R

1982-10-01

The colonization of S. mutans serotypes on different tooth surfaces of the rat was investigated. Fissures appeared to be the main habitat. In the presence of a serotype c strain, S. mutans serotype d could only be established when sucrose-containing diets were supplied. However, the serotype c strain was always present in higher proportions. The production of a bacteriocin for which the serotype d strain was sensitive appeared to be responsible for the observed predominance of the serotype c strain.

Genetic studies on reference strains of mutans streptococci.

PubMed

Ota, Fusao; Yamato, Masayuki; Hayashi, Mie; Ota, Masayuki; Koga, Tetsuro; Sherin, Ahmed; Mukai, Chiharu; Sakai, Kentaro; Yamamoto, Shigeru

2002-01-01

Twenty four reference strains (serotype a-h) belonging to the mutans group of streptococci were compared for DNA fragment patterns of rDNA after treatment with Hind III. It was shown that Streptococcus cricetus (serotype a), S. rattus (serotype b), and S. downei (serotype h) reveals comparatively homogeneous patterns while S. mutans (serotype c, e and f) exhibits differences between the different serotypes as well as within single serotypes. S. sobrinus had an intermediary diversity. These data support the previous findings that S. mutans is heterogeneous at the serological, biochemical and genetical level.

Serotypes in Saccharomyces telluris: Their relation to source of isolation

USGS Publications Warehouse

Hasenclever, H.F.; Kocan, R.M.

1973-01-01

Three serotypes have been characterized with three reference strains of Saccharomyces telluris and designated as A, B, and C. One reference strain of Torpulopsis bovina, the imperfect form of S. telluris, belonged to serotype B. Strains of S. telluris isolated from four columbid species were serotyped. All 98 strains of this yeast isolated from Columba livia belonged to serotype B. Three other columbid species, C. leucocephala, C. fasciata, and Zenaidura macroura harbored strains of serotype C only. Serotype A was not isolated from any of the avian species.

Increase in serotype 19A prevalence and amoxicillin non-susceptibility among paediatric Streptococcus pneumoniae isolates from middle ear fluid in a passive laboratory-based surveillance in Spain, 1997-2009

PubMed Central

2011-01-01

Background Conjugate vaccines, such as the 7-valent conjugate vaccine (PCV7), alter serotype nasopharyngeal carriage, potentially increasing cases of otitis media by non-vaccine serotypes. Methods All paediatric middle ear fluid (MEF) isolates received in the Spanish Reference Laboratory for Pneumococci through a passive, laboratory-based surveillance system from January 1997 to June 2009 were analysed. Data from 1997 to 2000 were pooled as pre-vaccination period. Trends over time were explored by linear regression analysis. Results A total of 2,077 isolates were analysed: 855 belonging to PCV7 serotypes, 466 to serotype 19A, 215 to serotype 3, 89 to serotype 6A and 452 to other serotypes (< 40 isolates each). Over time, there has been a decreasing trend for PCV7 serotypes (R2 = 0.944; p < 0.001, with significant decreasing trends for serotypes 19F, 14, 23F and 9V), and increasing trends for serotype 19A (R2 = 0.901; p < 0.001), serotype 3 (R2 = 0.463; p = 0.030) and other non-PCV7 serotypes (R2 = 0.877; p < 0.001), but not for serotype 6A (R2 = 0.311; p = 0.094). Considering all isolates, amoxicillin non-susceptibility showed an increasing trend (R2 = 0.528; p = 0.017). Regarding serotype 19A, increasing trends in non-susceptibility to penicillin (R2 = 0.726; p = 0.001), amoxicillin (R2 = 0.804; p < 0.001), cefotaxime (R2 = 0.546; p = 0.005) and erythromycin (R2 = 0.546; p = 0.009) were found, with amoxicillin non-susceptibility firstly detected in 2003 (7.4%) and increasing up to 38.0% in 2009. In PCV7 serotypes (which prevalence decreased from 70.7% during 1997-2000 to 10.6% in 2009) amoxicillin non-susceptibility rates showed an increasing trend (R2 = 0.702; p = 0.002). However, overall, amoxicillin non-susceptibility (≈25% in 2008-9) could be mainly attributed to serotype 19A (> 35% isolates) since PCV7 strains represented < 11% of total clinical isolates. Conclusions In contrast to reports on invasive pneumococcal strains, in MEF isolates the reduction in the prevalence of PCV7 serotypes was not associated with decreases in penicillin/erythromycin non-susceptibility. The high prevalence of serotype 19A among paediatric MEF isolates and the amoxicillin non-susceptibility found in this serotype are worrisome since amoxicillin is the most common antibiotic used in the treatment of acute otitis media. These data suggest that non-PCV7 serotypes (mainly serotype 19A followed by serotypes 3 and 6A) are important etiological agents of acute otitis media and support the added value of the broader coverage of the new 13-valent conjugate vaccine. PMID:21910891

Sequetyping: Serotyping Streptococcus pneumoniae by a Single PCR Sequencing Strategy

PubMed Central

Leung, Marcus H.; Bryson, Kevin; Freystatter, Kathrin; Pichon, Bruno; Edwards, Giles; Gillespie, Stephen H.

2012-01-01

The introduction of pneumococcal conjugate vaccines necessitates continued monitoring of circulating strains to assess vaccine efficacy and replacement serotypes. Conventional serological methods are costly, labor-intensive, and prone to misidentification, while current DNA-based methods have limited serotype coverage requiring multiple PCR primers. In this study, a computer algorithm was developed to interrogate the capsulation locus (cps) of vaccine serotypes to locate primer pairs in conserved regions that border variable regions and could differentiate between serotypes. In silico analysis of cps from 92 serotypes indicated that a primer pair spanning the regulatory gene cpsB could putatively amplify 84 serotypes and differentiate 46. This primer set was specific to Streptococcus pneumoniae, with no amplification observed for other species, including S. mitis, S. oralis, and S. pseudopneumoniae. One hundred thirty-eight pneumococcal strains covering 48 serotypes were tested. Of 23 vaccine serotypes included in the study, most (19/22, 86%) were identified correctly at least to the serogroup level, including all of the 13-valent conjugate vaccine and other replacement serotypes. Reproducibility was demonstrated by the correct sequetyping of different strains of a serotype. This novel sequence-based method employing a single PCR primer pair is cost-effective and simple. Furthermore, it has the potential to identify new serotypes that may evolve in the future. PMID:22553238

A serotype-specific polymerase chain reaction for identification of Pasteurella multocida serotype 1

USGS Publications Warehouse

Rocke, Tonie E.; Smith, Susan R.; Miyamoto, Amy; Shadduck, Daniel J.

2002-01-01

A serotype-specific polymerase chain reaction (PCR) assay was developed for detection and identification of Pasteurella multocida serotype 1, the causative agent of avian cholera in wild waterfowl. Arbitrarily primed PCR was used to detect DNA fragments that distinguish serotype 1 from the other 15 serotypes of P. multocida (with the exception of serotype 14). Oligonucleotide primers were constructed from these sequences, and a PCR assay was optimized and evaluated. PCR reactions consistently resulted in amplification products with reference strains 1 and 14 and all other serotype 1 strains tested, with cell numbers as low as 2.3 cells/ml. No amplification products were produced with other P. multocida serotypes or any other bacterial species tested. To compare the sensitivity and further test the specificity of this PCR assay with traditional culturing and serotyping techniques, tissue samples from 84 Pekin ducks inoculated with field strains of P. multocida and 54 wild lesser snow geese collected during an avian cholera outbreak were provided by other investigators working on avian cholera. PCR was as sensitive (58/64) as routine isolation (52/64) in detecting and identifying P. multocida serotype 1 from the livers of inoculated Pekins that became sick or died from avian cholera. No product was amplified from tissues of 20 other Pekin ducks that received serotypes other than type 1 (serotype 3, 12 × 3, or 10) or 12 control birds. Of the 54 snow geese necropsied and tested for P. multocida, our PCR detected and identified the bacteria from 44 compared with 45 by direct isolation. The serotype-specific PCR we developed was much faster and less labor intensive than traditional culturing and serotyping procedures and could result in diagnosis of serotype 1 pasteurellosis within 24 hr of specimen submission.

Development of a rapid serotyping method for Salmonella enterica using serotype-specific single-nucleotide polymorphisms

USDA-ARS?s Scientific Manuscript database

Salmonella enterica subsp. enterica serotype Enteriditis (S. Enteriditis) is the leading cause of salmonellosis worldwide, including the USA. Many S. enterica serotypes known to cause foodborne disease are associated with broiler meat contamination. While some serotypes are specific to birds (S. e...

Epidemiological survey of Streptococcus mutans among Japanese children. Identification and serological typing of the isolated strains.

PubMed

Hamada, S; Masuda, N; Ooshima, T; Sobue, S; Kotani, S

1976-02-01

An epidemiological investigation was carried out to identify and determine the serotypes of Streptococcus mutans from carious lesions of young Japanese children. For this purpose, a direct fluorescent antibody technique was mainly used. Fluorescein isothiocyanate-conjugated antibodies were prepared for the five known serotypes of S. mutans. Cross reactions and nonspecific reactions were eliminated by adsorption, counterstaining, or DEAE-cellulosecolumn chromatography. Agar-gel immunodiffusion was used to distinguish between serotypes a and d. The epidemiological survey suggested that serotype c strains were most prevalent in dental plaques of Japanese children. The d and e serotypes were rare and serotypes a and b were not detected. It was also noted that more than one serotype of S. mutans could be found in the same locus of a carious lesion and that there might be no relationship between the degree of caries and the causative serotype(s) of S. mutans.

Assessment of Strain Relatedness among Salmonella Serotypes Salinatis, Duisburg, and Sandiego by Biotyping, Ribotyping, IS200 Fingerprinting, and Pulsed-Field Gel Electrophoresis

PubMed Central

Old, David C.; Rankin, Shelley C.; Crichton, Pamela B.

1999-01-01

Salinatis (antigenic formula, 4,12:d:eh:enz15) is a rare Salmonella serotype currently designated a triphasic variant of the diphasic serotype Duisburg (1,4,12,27:d:enz15) (underlining indicates that the O antigen is determined by phage lysogenization). Salinatis could also be related to serotype Sandiego (4,[5],12:eh:enz15), from which it might have been derived by loss of H-d flagellin genes. Nineteen Salmonella strains of serotypes Salinatis, Duisburg, and Sandiego were examined by biotyping, PvuII and SmaI ribotyping, IS200 fingerprinting, and pulsed-field gel electrophoretic profiling. Results from these methods, used alone or together, indicate that serotype Salinatis is more likely to be related to serotype Sandiego than to serotype Duisburg. For future lists of serotype names, it is recommended that Salinatis be considered a variant of Sandiego. PMID:10325308

Blood invasiveness of Salmonella enterica as a function of age and serotype.

PubMed Central

Weinberger, M.; Andorn, N.; Agmon, V.; Cohen, D.; Shohat, T.; Pitlik, S. D.

2004-01-01

We explored the dual influence of the patient's age and the infecting serotype on the blood invasiveness patterns of non-Typhi Salmonella enterica (NTS). Blood invasiveness ratio (BIR) was calculated as the ratio between the number of blood and blood + stool isolates. Analysis of 14,951 NTS isolates showed that the BIR increased drastically above the age of 60 years, reaching levels 3.5-7 times higher compared to age group < 2 years. Different patterns of age-related invasiveness were observed for the five most common NTS serotypes (Enteritidis, Typhimurium, Virchow, Hadar, Infantis). Among children < 2 years, the BIR was highest for serotype Virchow and lowest for serotype Hadar, while in persons > or = 60 years it was highest for serotypes Enteritidis and lowest for serotype Infantis. The tendency of NTS serotypes to invade the bloodstream was significantly influenced by the patient's age, however the impact of age differed for various NTS serotypes. PMID:15635958

Serotypic characterization of rotaviruses derived from asymptomatic human neonatal infections.

PubMed Central

Hoshino, Y; Wyatt, R G; Flores, J; Midthun, K; Kapikian, A Z

1985-01-01

Nineteen rotavirus strains derived from asymptomatic neonates (seven from England, five from Australia, two from Venezuela, and five from Sweden) were successfully cultivated in primary African green monkey kidney cell cultures, serotyped by plaque reduction neutralization tests, subgrouped by indirect enzyme-linked immunosorbent assay, and electropherotyped by polyacrylamide gel electrophoresis. All 19 strains were shown to fall into one of the four known human serotypes; serotype 1 (all Venezuelan strains), serotype 2 (all Swedish strains), serotype 3 (all Australian strains), or serotype 4 (all English strains). Hyperimmune guinea pig serum raised against the Venezuelan strain (M37) neutralized not only serotype 1 (strain Wa) but also serotype 4 (strain St. Thomas no. 3) viruses to a similar degree. The English, Australian, and Venezuelan isolates were found to belong to subgroup 2, and the Swedish strains were subgroup 1 viruses. The potential importance of these rotaviruses obtained from neonates as possible vaccine candidates is discussed. Images PMID:2984247

Opsonophagocytic Antibodies to Serotype Ia, Ib, and III Group B Streptococcus among Korean Infants and in Intravenous Immunoglobulin Products.

PubMed

Kim, Han Wool; Lee, Ji Hyen; Cho, Hye Kyung; Lee, Hyunju; Seo, Ho Seong; Lee, Soyoung; Kim, Kyung Hyo

2017-05-01

Group B streptococcus (GBS) infection is a leading cause of sepsis and meningitis among infants, and is associated with high rates of morbidity and mortality in many countries. Protection against GBS typically involves antibody-mediated opsonization by phagocytes and complement components. The present study evaluated serotype-specific functional antibodies to GBS among Korean infants and in intravenous immunoglobulin (IVIG) products. An opsonophagocytic killing assay (OPA) was used to calculate the opsonization indices (OIs) of functional antibodies to serotypes Ia, Ib, and III in 19 IVIG products from 5 international manufacturers and among 98 Korean infants (age: 0-11 months). The GBS Ia, Ib, and III serotypes were selected because they are included in a trivalent GBS vaccine formulation that is being developed. The OI values for the IVIG products were 635-5,706 (serotype Ia), 488-1,421 (serotype Ib), and 962-3,315 (serotype III), and none of the IVIG lots exhibited undetectable OI values (< 4). The geometric mean OI values were similar for all 3 serotypes when we compared the Korean manufacturers. The seropositive rate among infants was significantly lower for serotype Ia (18.4%), compared to serotype Ib and serotype III (both, 38.8%). Infant age of ≥ 3 months was positively correlated with the seropositive rates for each serotype. Therefore, only a limited proportion of infants exhibited protective immunity against serotype Ia, Ib, and III GBS infections. IVIG products that exhibit high antibody titers may be a useful therapeutic or preventive measure for infants. Further studies are needed to evaluate additional serotypes and age groups. © 2017 The Korean Academy of Medical Sciences.

Opsonophagocytic Antibodies to Serotype Ia, Ib, and III Group B Streptococcus among Korean Infants and in Intravenous Immunoglobulin Products

PubMed Central

2017-01-01

Group B streptococcus (GBS) infection is a leading cause of sepsis and meningitis among infants, and is associated with high rates of morbidity and mortality in many countries. Protection against GBS typically involves antibody-mediated opsonization by phagocytes and complement components. The present study evaluated serotype-specific functional antibodies to GBS among Korean infants and in intravenous immunoglobulin (IVIG) products. An opsonophagocytic killing assay (OPA) was used to calculate the opsonization indices (OIs) of functional antibodies to serotypes Ia, Ib, and III in 19 IVIG products from 5 international manufacturers and among 98 Korean infants (age: 0–11 months). The GBS Ia, Ib, and III serotypes were selected because they are included in a trivalent GBS vaccine formulation that is being developed. The OI values for the IVIG products were 635–5,706 (serotype Ia), 488–1,421 (serotype Ib), and 962–3,315 (serotype III), and none of the IVIG lots exhibited undetectable OI values (< 4). The geometric mean OI values were similar for all 3 serotypes when we compared the Korean manufacturers. The seropositive rate among infants was significantly lower for serotype Ia (18.4%), compared to serotype Ib and serotype III (both, 38.8%). Infant age of ≥ 3 months was positively correlated with the seropositive rates for each serotype. Therefore, only a limited proportion of infants exhibited protective immunity against serotype Ia, Ib, and III GBS infections. IVIG products that exhibit high antibody titers may be a useful therapeutic or preventive measure for infants. Further studies are needed to evaluate additional serotypes and age groups. PMID:28378545

The Pneumococcal Serotype 15C Capsule Is Partially O-Acetylated and Allows for Limited Evasion of 23-Valent Pneumococcal Polysaccharide Vaccine-Elicited Anti-Serotype 15B Antibodies

PubMed Central

Spencer, Brady L.; Shenoy, Anukul T.; Orihuela, Carlos J.

2017-01-01

ABSTRACT As a species, Streptococcus pneumoniae (the pneumococcus) utilizes a diverse array of capsular polysaccharides to evade the host. In contrast to large variations in sugar composition and linkage formation, O-acetylation is a subtle capsular modification that nonetheless has a large impact on capsular shielding and recognition of the capsule by vaccine-elicited antibodies. Serotype 15B, which is included in the 23-valent pneumococcal polysaccharide vaccine (PPV23), carries the putative O-acetyltransferase gene wciZ. The coding sequence of wciZ contains eight consecutive TA repeats [(TA)8]. Replication slippage is thought to result in the addition or loss of TA repeats, subsequently causing frameshift and truncation of WciZ to yield a nonacetylated serotype, 15C. Using sensitive serological tools, we show that serotype 15C isolates whose wciZ contains seven or nine TA repeats retain partial O-acetylation, while serotype 15C isolates whose wciZ contains six TA repeats have barely detectable O-acetylation. We confirmed by inhibition enzyme-linked immunosorbent assay that (TA)7 serotype 15C is ∼0.1% as acetylated as serotype 15B, while serotype 15X is nonacetylated. To eliminate the impact of genetic background, we created isogenic serotype 15B, (TA)7 serotype 15C, and 15BΔwciZ (15X) strains and found that reduction or absence of WciZ-mediated O-acetylation did not affect capsular shielding from phagocytes, biofilm formation, adhesion to nasopharyngeal cells, desiccation tolerance, or murine colonization. Sera from PPV23-immunized persons opsonized serotype 15B significantly but only slightly better than serotypes 15C and 15X; thus, PPV23 may not result in expansion of serotype 15C. PMID:28637806

An Evaluation of Voluntary Varicella Vaccination Coverage in Zhejiang Province, East China.

PubMed

Hu, Yu; Chen, Yaping; Zhang, Bing; Li, Qian

2016-06-03

In 2014 a 2-doses varicella vaccine (VarV) schedule was recommended by the Zhejiang Provincial Center for Disease Control and Prevention. We aimed to assess the coverage of the 1st dose of VarV (VarV₁) and the 2nd dose of VarV (VarV₂) among children aged 2-6 years through the Zhejiang Provincial Immunization Information System (ZJIIS) and to explore the determinants associated with the VarV coverage. Children aged 2-6 years (born from 1 January 2009 to 31 December 2013) registered in ZJIIS were enrolled. Anonymized individual records of target children were extracted from the ZJIIS database on 1 January 2016, including their VarV and (measles-containing vaccine) MCV vaccination information. The VarV₁ and VarV₂ coverage rates were evaluated for each birth cohorts. The coverage of VarV also was estimated among strata defined by cities, gender and immigration status. We also evaluated the difference in coverage between VarV and MCV. A total of 3,028,222 children aged 2-6 years were enrolled. The coverage of VarV₁ ranged from 84.8% to 87.9% in the 2009-2013 birth cohorts, while the coverage of VarV₂ increased from 31.8% for the 2009 birth cohort to 48.7% for the 2011 birth cohort. Higher coverage rates for both VarV₁ and VarV₂ were observed among resident children in relevant birth cohorts. The coverage rates of VarV₁ and VarV₂ were lower than those for the 1st and 2nd dose of MCV, which were above 95%. The proportion of children who were vaccinated with VarV₁ at the recommended age increased from 34.6% for the 2009 birth cohort to 75.2% for the 2013 birth cohort, while the proportion of children who were vaccinated with VarV₂ at the recommended age increased from 19.7% for the 2009 birth cohort to 48.7% for the 2011 birth cohort. Our study showed a rapid increasing VarV₂ coverage of children, indicating a growing acceptance of the 2-doses VarV schedule among children's caregivers and physicians after the new recommendation released. We highlighted the necessity for a 2-doses VarV vaccination school-entry requirement to achieve the high coverage of >90% and to eliminate disparities in coverage among sub-populations. We also recommended continuous monitoring of the VarV coverage via ZJIIS over time.

Draft Genome Sequences of Clinical Isolates of Serotype 6E Streptococcus pneumoniae from Five Asian Countries.

PubMed

Park, In Ho; Baek, Jin Yang; Song, Jae-Hoon; Ko, Kwan Soo; Kim, Kyung-Hyo

2017-03-09

Although serotype 6E Streptococcus pneumoniae consistently expresses capsules of either vaccine-serotype 6A or 6B, certain genetic variants of serotype 6E may evade vaccine induced immunity. Thus, draft genome sequences from five clinical isolates of serotype 6E from each of five different Asian countries have been generated to provide insight into the genomic diversity in serotype 6E strains. Copyright © 2017 Park et al.

Rotavirus Diarrhea Severity Is Related to the VP4 Type in Mexican Children

PubMed Central

Mota-Hernández, Felipe; José Calva, Juan; Gutiérrez-Camacho, Claudia; Villa-Contreras, Sofía; Arias, Carlos F.; Padilla-Noriega, Luis; Guiscafré-Gallardo, Héctor; Guerrero, María de Lourdes; López, Susana; Muñoz, Onofre; Contreras, Juan F.; Cedillo, Roberto; Herrera, Ismael; Puerto, Fernando I.

2003-01-01

This report is of a community-based case control study to assess whether the severity of acute diarrhea by rotavirus (RV) in young children is associated with a particular VP7 (G) or VP4 (P) RV serotype. Five hundred twenty children younger than 2 years of age with diarrhea lasting less than 3 days were age and gender matched with 520 children with no diarrhea. The G and P serotypes were determined with specific monoclonal antibodies, and the VP4 serotype specificity in a subgroup was confirmed by genotyping. Infection with a G3 serotype led to a higher risk of diarrhea than infection with a G1 serotype. Infection with a G3-nontypeable-P serotype was associated with more severe gastroenteritis than infection with a G3 (or G1) P1A[8] serotype. A child with diarrhea-associated dehydration was almost five times more likely to be infected with a G3-nontypeable-P serotype than a child without dehydration (P < 0.001). Moreover, the two predominant monotypes within serotype P1A[8] had significantly different clinical manifestations. In this study, the severity of RV-associated diarrhea was related to different P serotypes rather than to G serotypes. The relationship between serotype and clinical outcomes seems to be complex and to vary among different geographic areas. PMID:12843057

Rotavirus diarrhea severity is related to the VP4 type in Mexican children.

PubMed

Mota-Hernández, Felipe; Calva, Juan José; Gutiérrez-Camacho, Claudia; Villa-Contreras, Sofía; Arias, Carlos F; Padilla-Noriega, Luis; Guiscafré-Gallardo, Héctor; de Lourdes Guerrero, María; López, Susana; Muñoz, Onofre; Contreras, Juan F; Cedillo, Roberto; Herrera, Ismael; Puerto, Fernando I

2003-07-01

This report is of a community-based case control study to assess whether the severity of acute diarrhea by rotavirus (RV) in young children is associated with a particular VP7 (G) or VP4 (P) RV serotype. Five hundred twenty children younger than 2 years of age with diarrhea lasting less than 3 days were age and gender matched with 520 children with no diarrhea. The G and P serotypes were determined with specific monoclonal antibodies, and the VP4 serotype specificity in a subgroup was confirmed by genotyping. Infection with a G3 serotype led to a higher risk of diarrhea than infection with a G1 serotype. Infection with a G3-nontypeable-P serotype was associated with more severe gastroenteritis than infection with a G3 (or G1) P1A[8] serotype. A child with diarrhea-associated dehydration was almost five times more likely to be infected with a G3-nontypeable-P serotype than a child without dehydration (P < 0.001). Moreover, the two predominant monotypes within serotype P1A[8] had significantly different clinical manifestations. In this study, the severity of RV-associated diarrhea was related to different P serotypes rather than to G serotypes. The relationship between serotype and clinical outcomes seems to be complex and to vary among different geographic areas.

Application of bluetongue Disabled Infectious Single Animal (DISA) vaccine for different serotypes by VP2 exchange or incorporation of chimeric VP2.

PubMed

Feenstra, Femke; Pap, Janny S; van Rijn, Piet A

2015-02-04

Bluetongue is a disease of ruminants caused by the bluetongue virus (BTV). Bluetongue outbreaks can be controlled by vaccination, however, currently available vaccines have several drawbacks. Further, there are at least 26 BTV serotypes, with low cross protection. A next-generation vaccine based on live-attenuated BTV without expression of non-structural proteins NS3/NS3a, named Disabled Infectious Single Animal (DISA) vaccine, was recently developed for serotype 8 by exchange of the serotype determining outer capsid protein VP2. DISA vaccines are replicating vaccines but do not cause detectable viremia, and induce serotype specific protection. Here, we exchanged VP2 of laboratory strain BTV1 for VP2 of European serotypes 2, 4, 8 and 9 using reverse genetics, without observing large effects on virus growth. Exchange of VP2 from serotype 16 and 25 was however not possible. Therefore, chimeric VP2 proteins of BTV1 containing possible immunogenic regions of these serotypes were studied. BTV1, expressing 1/16 chimeric VP2 proteins was functional in virus replication in vitro and contained neutralizing epitopes of both serotype 1 and 16. For serotype 25 this approach failed. We combined VP2 exchange with the NS3/NS3a negative phenotype in BTV1 as previously described for serotype 8 DISA vaccine. DISA vaccine with 1/16 chimeric VP2 containing amino acid region 249-398 of serotype 16 raised antibodies in sheep neutralizing both BTV1 and BTV16. This suggests that DISA vaccine could be protective for both parental serotypes present in chimeric VP2. We here demonstrate the application of the BT DISA vaccine platform for several serotypes and further extend the application for serotypes that are unsuccessful in single VP2 exchange. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inter-serotype comparison of polysaccharides produced by extracellular enzymes from Streptococcus mutans.

PubMed

Yakushiji, T; Inoue, M; Koga, T

1984-04-15

The biochemical and morphological characteristics of polysaccharides synthesized from sucrose by extracellular enzymes from D-glucose-grown Streptococcus mutans representing serotypes a-g were compared. The polysaccharides synthesized by the enzymes from serotypes a, d, and g formed visible aggregates and firmly adhered to glass surfaces, whereas those formed by the enzymes from serotypes b, c, e, and f floated homogeneously and were poorly adherent. The enzymes of serotypes a, d, and g produced large amounts of water-insoluble polysaccharides (IPs, D-glucans), and those of serotypes b, c, e, and f water-soluble polysaccharides (SPs, D-glucans and D- fructans ). As compared with the IPs of serotypes b, c, e, and f, the IPs of serotypes a, d, and g (a) contained a higher proportion of (1----3)-alpha-D-glucosidic linkages and alpha-D-(1----3,6) branch linkages; (b) showed higher susceptibility to (1----3)-alpha-D-glucanase (serotype a excepted) and lower (1----6)-alpha-D-glucanase sensitivity; (c) contained larger amounts of high-molecular-weight fractions; (d) showed higher intrinsic viscosities (serotype b excepted); and (e) had lower S. mutans cell-agglutination activities. On electron-microscope observation, the IPs of all serotypes showed two fibrillar components; a double-stranded fibril, with short, fluffy protrusions extending out of its periphery, and a fine, single-stranded fibril. Thus, the serotypes could be divided into two major groups: a, d, and g; and b, c, e, and f. No similar grouping of serotypes was indicated by the chemical and morphological properties of SPs.

Prevention of Streptococcus mutans colonization by salivary IgA antibodies.

PubMed

Gregory, R L; Michalek, S M; Filler, S J; Mestecky, J; McGhee, J R

1985-01-01

The levels of salivary and serum IgA, IgG, and IgM antibodies to the seven serotypes (a-g) of Streptococcus mutans were established in 12 laboratory volunteers using a sensitive enzyme-linked immunosorbent assay. Salivary IgA antibody levels to the serotype c organism were significantly lower (P less than 0.005) than antibody levels to the other six serotypes of S. mutans. Similar results were found with a purified S. mutans serotype c carbohydrate. Serum IgG and IgM antibody titers to the serotype c whole cells were significantly higher (P less than 0.05) than to four other S. mutans serotypes (a, e-g). The abilities of S. mutans serotypes c and d to colonize molar tooth surfaces were examined in eight volunteers. S. mutans serotype d was cleared from the tooth surfaces within 24 hr of challenge, whereas S. mutans serotype c was detected in six of the eight volunteers after 2 weeks and in three of eight after 3 weeks. These results provide additional evidence for the role of salivary IgA antibodies in regulating S. mutans infection and suggest that the low levels of salivary IgA antibodies to S. mutans serotype c may contribute to the predominance of this serotype in the U.S. population.

Structural and Genetic Analyses of O Polysaccharide from Actinobacillus actinomycetemcomitans Serotype f

PubMed Central

Kaplan, Jeffrey B.; Perry, Malcolm B.; MacLean, Leann L.; Furgang, David; Wilson, Mark E.; Fine, Daniel H.

2001-01-01

The oral bacterium Actinobacillus actinomycetemcomitans is implicated as a causative agent of localized juvenile periodontitis (LJP). A. actinomycetemcomitans is classified into five serotypes (a to e) corresponding to five structurally and antigenically distinct O polysaccharide (O-PS) components of their respective lipopolysaccharide molecules. Serotype b has been reported to be the dominant serotype isolated from LJP patients. We determined the lipopolysaccharide O-PS structure from A. actinomycetemcomitans CU1000, a strain isolated from a 13-year-old African-American female with LJP which had previously been classified as serotype b. The O-PS of strain CU1000 consisted of a trisaccharide repeating unit composed of l-rhamnose and 2-acetamido-2-deoxy-d-galactose (molar ratio, 2:1) with the structure →2)-α-l-Rhap-(1–3)-2-O-(β-d-GalpNAc)-α-l-Rhap-(1→. O-PS from strain CU1000 was structurally and antigenically distinct from the O-PS molecules of the five known A. actinomycetemcomitans serotypes. Strain CU1000 was mutagenized with transposon IS903φkan, and three mutants that were deficient in O-PS synthesis were isolated. All three transposon insertions mapped to a single 1-kb region on the chromosome. The DNA sequence of a 13.1-kb region surrounding these transposon insertions contained a cluster of 14 open reading frames that was homologous to gene clusters responsible for the synthesis of A. actinomycetemcomitans serotype b, c, and e O-PS antigens. The CU1000 gene cluster contained two genes that were not present in serotype-specific O-PS antigen clusters of the other five known A. actinomycetemcomitans serotypes. These data indicate that strain CU1000 should be assigned to a new A. actinomycetemcomitans serotype, designated serotype f. A PCR assay using serotype-specific PCR primers showed that 3 out of 20 LJP patients surveyed (15%) harbored A. actinomycetemcomitans strains carrying the serotype f gene cluster. The finding of an A. actinomycetemcomitans serotype showing serological cross-reactivity with anti-serotype b-specific antiserum suggests that a reevaluation of strains previously classified as serotype b may be warranted. PMID:11500407

Serotype classification of Streptococcus mutans and its detection outside the oral cavity.

PubMed

Nakano, Kazuhiko; Ooshima, Takashi

2009-09-01

Streptococcus mutans, generally known as a major pathogen of dental caries, is also a possible causative agent of bacteremia and infective endocarditis. S. mutans is classified into serotypes c, e, f and k based on the chemical composition of serotype-specific polysaccharides, with approximately 70-80% of strains found in the oral cavity classified as serotype c, followed by e (approximately 20%), and f and k (less than 5% each). Serotype k was recently designated as a novel serotype and shown to possess unique features, the most prominent being a defect of the glucose side chain in serotype-specific rhamnose-glucose polymers, which is related to a higher incidence of detection in cardiovascular specimens, owing to phagocytosis resistance. Molecular analyses of cardiovascular specimens showed a high detection frequency for S. mutans DNA, among which the detection rate for serotype k was quite high. These findings suggest that serotype k S. mutans possibly has a high level of virulence for systemic diseases.

The serotype-specific glucose side chain of rhamnose-glucose polysaccharides is essential for adsorption of bacteriophage M102 to Streptococcus mutans.

PubMed

Shibata, Yukie; Yamashita, Yoshihisa; van der Ploeg, Jan R

2009-05-01

Bacteriophage M102 is a virulent siphophage that propagates in some serotype c Streptococcus mutans strains, but not in S. mutans of serotype e, f or k. The serotype of S. mutans is determined by the glucose side chain of rhamnose-glucose polysaccharide (RGP). Because the first step in the bacteriophage infection process is adsorption of the phage, it was investigated whether the serotype specificity of phage M102 was determined by adsorption. M102 adsorbed to all tested serotype c strains, but not to strains of different serotypes. Streptococcus mutans serotype c mutants defective in the synthesis of the glucose side chain of RGP failed to adsorb phage M102. These results suggest that the glucose side chain of RGP acts as a receptor for phage M102.

Evaluation of cross-protection of bluetongue virus serotype 4 with other serotypes in sheep.

PubMed

Zulu, Gcwalisile B; Venter, Estelle H

2014-10-16

Bluetongue (BT) is a non-contagious disease of sheep and other domestic and wild ruminants caused by the bluetongue virus (BTV). Currently 26 serotypes of the virus have been identified. In South Africa, 22 serotypes have been identified and BT is controlled mainly by annual vaccinations using a freeze-dried live attenuated polyvalent BTV vaccine. The vaccine is constituted of 15 BTV serotypes divided into three separate bottles and the aim is to develop a vaccine using fewer serotypes without compromising the immunity against the disease. This study is based on previously reported cross-neutralisation of specific BTV serotypes in in vitro studies. Bluetongue virus serotype 4 was selected for this trial and was tested for cross-protection against serotype 4 (control), 1 (unrelated serotype), 9, 10 and 11 in sheep using the serum neutralisation test. The purpose of the study was to determine possible cross-protection of different serotypes in sheep. Of those vaccinated with BTV-4 and challenged with BTV-1, which is not directly related to BTV-4, 20% were completely protected and 80% showed clinical signs, but the reaction was not as severe as amongst the unvaccinated animals. In the group challenged with BTV-10, some showed good protection and some became very sick. Those challenged with BTV-9 and BTV-11 had good protection. The results showed that BTV-4 does not only elicit a specific immune response but can also protect against other serotypes.

Cytotaxonomic study of the Chilean endemic complex Alstroemeria magnifica Herb. (Alstroemeriaceae).

PubMed

Baeza, Carlos M; Finot, Víctor; Ruiz, Eduardo; Carrasco, Pedro; Novoa, Patricio; Rosas, Marcelo; Toro-Núñez, Oscar

2018-05-14

Alstroemeria L. (Alstroemeriaceae) represents one of the most diverse genera of vascular plants in Chile. It contains approximately 54 taxa, 40 of which are endemic. The "complex" Alstroemeria magnifica is endemic to Chile, and it comprises four varieties: A. magnifica var. magenta, A. magnifica var. magnifica, A. magnifica var. sierrae, and A. magnifica var. tofoensis. It is distributed from Coquimbo to the Valparaíso Region. We analyzed karyotypes of 10 populations along its natural distribution. All the populations presented an asymmetric karyotype, with 2n = 16 chromosomes but with three different karyotypic formulae. Alstroemeria magnifica var. magnifica and A. magnifica var. sierrae presented the same karyotypic fomula, and A. magnifica var. magenta, and A. magnifica var. tofoensis each had a different formula. The scatter plot among CVCL vs. MCA shows different groupings between populations of the four varieties. Based on the results, it is possible to consider raising Alstroemeria magnifica var. magenta to species level (A. magenta) and A. magnifica var. tofoensis to subspecies level (A. magnifica subsp. tofoensis); A. magnifica var. magnifica and A. magnifica var. sierrae should each remain as varieties. Nevertheless, these taxonomic changes should be considered tentative, as additional sources of evidence become available.

Serotype specific polymerase chain reaction identifies a higher prevalence of streptococcus mutans serotype k and e in a random group of children with dental caries from the Southern region of India

PubMed Central

Rao, Arun Prasad; Austin, Ravi David

2014-01-01

Background: The development of dental caries has been associated with the oral prevalence of Streptococcus mutans. Four serotypes of S. mutans have been reported, namely serotype c, e, f, and k that are classified based on the composition and linkages of cell wall polysaccharides, response to physiological reactions, sero-specificity and 16s rRNA homology. Although the oral prevalence of S. mutans serotype c in Indian subjects with or without caries is known, the prevalence of the other three serotypes, e, f, and k are not known. Hence in this study, we have investigated the occurrence of the e, f, and k serotypes in children with or without caries within the age group of 6-12 years. Materials and Methods: Genomic DNA isolated from whole saliva of caries active (CA) and caries free (CF) groups were first screened for the presence of S. mutans by strain specific polymerase chain reaction (PCR). Those samples that tested positive for the presence of S. mutans were further analyzed by serotype specific PCR to identify the prevalence of the serotypes. Results: Strain specific PCR indicated a higher prevalence of S. mutans in CA group (80%) relative to CF group (43%). Further analysis of the S. mutans positive samples in both groups indicated a higher prevalence of serotype k and e, followed by serotype f in CA group. Conclusion: The present data clearly establishes a novel S. mutans serotype prevalence hierarchy in children from this region, compared with those that have been reported elsewhere. Besides, the data are also clinically significant as the occurrence of serotype k has been associated with infective endocarditis. PMID:25191062

Genetic diversity and comparison of diagnostic tests for characterization of foot-and-mouth disease virus strains from Pakistan 2008-2012.

PubMed

Ahmed, Z; Pauszek, S J; Ludi, A; LaRocco, M; Khan, E-U-H; Afzal, M; Arshed, M J; Farooq, U; Arzt, J; Bertram, M; Brito, B; Naeem, K; Abubakar, M; Rodriguez, L L

2018-04-01

We report the laboratory analysis of 125 clinical samples from suspected cases of foot-and-mouth disease (FMD) in cattle and Asian buffalo collected in Pakistan between 2008 and 2012. Of these samples, 89 were found to contain viral RNA by rRT-PCR, of which 88 were also found to contain infectious FMD virus (FMDV) by virus isolation (VI), with strong correlation between these tests (κ = 0.96). Samples that were VI-positive were serotyped by antigen detection ELISA (Ag-ELISA) and VP1 sequence acquisition and analysis. Sequence data identified FMDV serotypes A (n = 13), O (n = 36) and Asia-1 (n = 41), including three samples from which both serotypes Asia-1 and O were detected. Serotype A viruses were classified within three different Iran-05 sublineages: HER-10, FAR-11 and ESF-10. All serotype Asia-1 were within Group VII (Sindh-08 lineage), in a genetic clade that differs from viruses isolated prior to 2010. All serotypes O were classified as PanAsia-2 within two different sublineages: ANT-10 and BAL-09. Using VP1 sequencing as the gold standard for serotype determination, the overall sensitivity of Ag-ELISA to correctly determine serotype was 74%, and serotype-specific sensitivity was 8% for serotype A, 88% for Asia-1 and 89% for O. Serotype-specific specificity was 100% for serotype A, 93% for Asia-1 and 94% for O. Interestingly, 12 of 13 serotype A viruses were not detected by Ag-ELISA. This study confirms earlier accounts of regional genetic diversity of FMDV in Pakistan and highlights the importance of continued validation of diagnostic tests for rapidly evolving pathogens such as FMDV. © 2017 Blackwell Verlag GmbH.

Serotype specific polymerase chain reaction identifies a higher prevalence of streptococcus mutans serotype k and e in a random group of children with dental caries from the Southern region of India.

PubMed

Rao, Arun Prasad; Austin, Ravi David

2014-07-01

The development of dental caries has been associated with the oral prevalence of Streptococcus mutans. Four serotypes of S. mutans have been reported, namely serotype c, e, f, and k that are classified based on the composition and linkages of cell wall polysaccharides, response to physiological reactions, sero-specificity and 16s rRNA homology. Although the oral prevalence of S. mutans serotype c in Indian subjects with or without caries is known, the prevalence of the other three serotypes, e, f, and k are not known. Hence in this study, we have investigated the occurrence of the e, f, and k serotypes in children with or without caries within the age group of 6-12 years. Genomic DNA isolated from whole saliva of caries active (CA) and caries free (CF) groups were first screened for the presence of S. mutans by strain specific polymerase chain reaction (PCR). Those samples that tested positive for the presence of S. mutans were further analyzed by serotype specific PCR to identify the prevalence of the serotypes. Strain specific PCR indicated a higher prevalence of S. mutans in CA group (80%) relative to CF group (43%). Further analysis of the S. mutans positive samples in both groups indicated a higher prevalence of serotype k and e, followed by serotype f in CA group. The present data clearly establishes a novel S. mutans serotype prevalence hierarchy in children from this region, compared with those that have been reported elsewhere. Besides, the data are also clinically significant as the occurrence of serotype k has been associated with infective endocarditis.

[Homology analysis of the extended-V region of the surface proteins in different serotype Streptococcus mutans].

PubMed

He, Kui-Fang; Liu, Jian-Guo; Liu, Tian-Jia; Yang, De-Qin; Zhuang, Heng; Li, Song

2006-08-01

To analysis the homology among the extended-V region of the surface proteins in different serotype Streptococcus mutans (c, f, d, g) and to find out it's significance in anti-caries vaccine. The DNA of the bacteria (standarded serotype c, d, f, g and partial serotype c clinicals) was extracted and the extended-V region (SrV+, 1 384-2 514 bp) was amplified using polymerase chain reaction (PCR). Then the products were assessed using restriction fragment length polymorphism (RFLP) by endonuclease Dde I. The genotypings were sequenced and analysised using the program of BLAST on NCBI Gene Bank database. About 1.13 kb fragments were produced both in serotype c and f, the serotype d and g were failed. The RFLP results showed that five different patterns(A, B, C, D, E) among the 117 PCR products were reveled by Dde I. The ration of the genotypings A and B were the most among the strains, the C was lower, the D and E respectively was 1 and 3 strains per genotype. OMZ175 (serotype f) was belong to B genotype. Selected one of the A, B, C genotypings to sequenced and blasted. Then the results of the blastn showed that the identities of the gene sequence were 92%-98% between the serotype c and serotype f, part sequence of the serotype g was homology with the SrV+ of the serotype c, the protein sequence among serotype c, d, f, g were 77%-82%. It is reasonable to use some putative pipetides to study the anti-caries vaccine among the extended-V regions of the surface proteins in different serotype (c, d, f, g) in S. mutans.

Pasteurella multocida serotype 1 isolated from a lesser snow goose

USGS Publications Warehouse

Samuel, M.D.; Goldberg, Diana R.; Shadduck, D.J.; Price, J.I.; Cooch, E.G.

1997-01-01

Pharyngeal swabs were collected from 298 lesser snow geese (Chen caerulescens caerulescens) at Banks Island (Northwest Territories. Canada) in the summer of 1994. Pasteurella multocida serotype 1 was isolated from an adult male bird and P. multocida serotype 3 was isolated from an adult female goose. Pathogenicity of the serotype 1 isolate was confirmed by inoculation in Pekin ducks (Anas platyrhynchos). The serotype 3 isolate was non-pathogenic in Pekin ducks. This is the first documented isolation of pathogenic P. multocida serotype 1 from apparently healthy wild snow geese.

The Pneumococcal Serotype 15C Capsule Is Partially O-Acetylated and Allows for Limited Evasion of 23-Valent Pneumococcal Polysaccharide Vaccine-Elicited Anti-Serotype 15B Antibodies.

PubMed

Spencer, Brady L; Shenoy, Anukul T; Orihuela, Carlos J; Nahm, Moon H

2017-08-01

As a species, Streptococcus pneumoniae (the pneumococcus) utilizes a diverse array of capsular polysaccharides to evade the host. In contrast to large variations in sugar composition and linkage formation, O-acetylation is a subtle capsular modification that nonetheless has a large impact on capsular shielding and recognition of the capsule by vaccine-elicited antibodies. Serotype 15B, which is included in the 23-valent pneumococcal polysaccharide vaccine (PPV23), carries the putative O-acetyltransferase gene wciZ The coding sequence of wciZ contains eight consecutive TA repeats [(TA) 8 ]. Replication slippage is thought to result in the addition or loss of TA repeats, subsequently causing frameshift and truncation of WciZ to yield a nonacetylated serotype, 15C. Using sensitive serological tools, we show that serotype 15C isolates whose wciZ contains seven or nine TA repeats retain partial O-acetylation, while serotype 15C isolates whose wciZ contains six TA repeats have barely detectable O-acetylation. We confirmed by inhibition enzyme-linked immunosorbent assay that (TA) 7 serotype 15C is ∼0.1% as acetylated as serotype 15B, while serotype 15X is nonacetylated. To eliminate the impact of genetic background, we created isogenic serotype 15B, (TA) 7 serotype 15C, and 15BΔ wciZ (15X) strains and found that reduction or absence of WciZ-mediated O-acetylation did not affect capsular shielding from phagocytes, biofilm formation, adhesion to nasopharyngeal cells, desiccation tolerance, or murine colonization. Sera from PPV23-immunized persons opsonized serotype 15B significantly but only slightly better than serotypes 15C and 15X; thus, PPV23 may not result in expansion of serotype 15C. Copyright © 2017 American Society for Microbiology.

Induction of Broad-Spectrum Protective Immunity against Disparate Cryptococcus Serotypes

PubMed Central

Van Dyke, Marley C. Caballero; Chaturvedi, Ashok K.; Hardison, Sarah E.; Leopold Wager, Chrissy M.; Castro-Lopez, Natalia; Hole, Camaron R.; Wozniak, Karen L.; Wormley, Floyd L.

2017-01-01

Cryptococcosis is a fungal disease caused by multiple Cryptococcus serotypes; particularly C. neoformans (serotypes A and D) and C. gattii (serotypes B and C). To date, there is no clinically available vaccine to prevent cryptococcosis. Mice given an experimental pulmonary vaccination with a C. neoformans serotype A strain engineered to produce interferon-γ, denoted H99γ, are protected against a subsequent otherwise lethal experimental infection with C. neoformans serotype A. Thus, we determined the efficacy of immunization with C. neoformans strain H99γ to elicit broad-spectrum protection in BALB/c mice against multiple disparate Cryptococcus serotypes. We observed significantly increased survival rates and significantly decreased pulmonary fungal burden in H99γ immunized mice challenged with Cryptococcus serotypes A, B, or D compared to heat-killed H99γ (HKH99γ) immunized mice. Results indicated that prolonged protection against Cryptococcus serotypes B or D in H99γ immunized mice was CD4+ T cell dependent and associated with the induction of predominantly Th1-type cytokine responses. Interestingly, immunization with H99γ did not elicit greater protection against challenge with the Cryptococcus serotype C tested either due to low overall virulence of this strain or enhanced capacity of this strain to evade host immunity. Altogether, these studies provide “proof-of-concept” for the development of a cryptococcal vaccine that provides cross-protection against multiple disparate serotypes of Cryptococcus. PMID:29163469

Serotype Distribution of Salmonella Isolates from Turkey Ground Meat and Meat Parts

PubMed Central

Erol, Irfan; Goncuoglu, Muammer; Ayaz, Naim Deniz; Ellerbroek, Lüppo; Bilir Ormanci, Fatma Seda; Iseri Kangal, Ozlem

2013-01-01

The aim of the study was to find out the serotype distribution of 169 Salmonella colonies recovered from 112 Salmonella positive ground turkey (115 colonies) and 52 turkey meat parts (54 colonies). Out of 15 Salmonella serotypes: S. Corvallis, S. Kentucky, S. Bredeney, S. Virchow, S. Saintpaul and S. Agona were identified as the predominant serovars at the rates of 27%, 13%, 12%, 12%, 11%, and 10%, respectively. Other serotypes were below 6% of the total isolates. All S. Kentucky and S. Virchow and most of the S. Corvallis (39/46) and S. Heidelberg (9/9) serotypes were recovered from ground turkey. The results indicate that turkey ground meat and meat parts were contaminated with quite distinct Salmonella serotypes. This is the first study reporting Salmonella serotype distribution in turkey meat and S. Corvallis as predominant serotype in poultry meat in Turkey. PMID:23936785

Serotype Distribution and Drug Resistance in Streptococcus pneumoniae, Palestinian Territories

PubMed Central

Kattan, Randa; Abu Rayyan, Amal; Zheiman, Inas; Idkeidek, Suzan; Baraghithi, Sabri; Rishmawi, Nabeel; Turkuman, Sultan; Abu-Diab, Afaf; Ghneim, Riyad; Zoughbi, Madeleine; Dauodi, Rula; Ghneim, Raed; Issa, Abed-El-Razeq; Siryani, Issa; Al Qas, Randa; Liddawi, Rawan; Khamash, Hatem; Kanaan, Moein; Marzouqa, Hiyam

2011-01-01

To determine antimicrobial drug resistance of Streptococcus pneumoniae serotypes, we analyzed isolates from blood cultures of sick children residing in the West Bank before initiation of pneumococcal vaccination. Of 120 serotypes isolated, 50.8%, 73.3%, and 80.8% of the bacteremia cases could have been prevented by pneumococcal conjugate vaccines. Serotype 14 was the most drug-resistant serotype isolated. PMID:21192863

The effect of pneumococcal conjugate vaccines on the incidence of invasive pneumococcal disease caused by ten non-vaccine serotypes in Denmark.

PubMed

Slotved, Hans-Christian; Dalby, Tine; Hoffmann, Steen

2016-02-03

Surveillance data on invasive pneumococcal disease (IPD) in Denmark (1999-2014) was analysed regarding the incidence and age-distribution due to ten selected non-PCV serotypes (10-Non-PCV). The effect of PCV-7 and PCV-13 vaccines on the 10-Non-PCV IPD incidence was examined. IPD cases caused by serotypes included in PCV-7, the additional six serotypes included in PCV-13 and 10-Non-PCV serotypes were identified (8, 9N, 11A, 12F, 15A, 22F, 24F, 20, 23B, 33F). The IPD incidence was stratified by three age groups: 0-4 years, 5-64 years and 65+ years. The predominant IPD cases were caused by serotypes that are not included in PCV-13 (71%), followed by the six additional PCV-13 serotypes. The IPD incidence of serotypes included in the PCV-7 decreased markedly after PCV-7 introduction but are still diagnosed at a low level. The IPD incidence for the 10-Non-PCV serotypes was low for age groups 0-4 years and 5-64 years but high for 65+ years. Future vaccinations of the young age group alone with a vaccine targeting some of the 10-Non-PCV serotypes may not elicit the desired effect on herd protection since these serotypes are primarily causing IPD among the elderly. Future pneumococcal vaccination strategies in Denmark may therefore need carriage studies in order to identify among whom the pneumococcal serotypes causing IPD are carried. Copyright © 2016 Elsevier Ltd. All rights reserved.

Novel chimeric foot-and-mouth disease virus-like particles harboring serotype O VP1 protect guinea pigs against challenge.

PubMed

Li, Haitao; Li, Zhiyong; Xie, Yinli; Qin, Xiaodong; Qi, Xingcai; Sun, Peng; Bai, Xingwen; Ma, Youji; Zhang, Zhidong

2016-02-01

Foot-and-mouth disease is a highly contagious, acute viral disease of cloven-hoofed animal species causing severe economic losses worldwide. Among the seven serotypes of foot-and-mouth disease virus (FMDV), serotype O is predominant, but its viral capsid is more acid sensitive than other serotypes, making it more difficult to produce empty serotype O VLPs in the low pH insect hemolymph. Therefore, a novel chimeric virus-like particle (VLP)-based candidate vaccine for serotype O FMDV was developed and characterized in the present study. The chimeric VLPs were composed of antigenic VP1 from serotype O and segments of viral capsid proteins from serotype Asia1. These VLPs elicited significantly higher FMDV-specific antibody levels in immunized mice than did the inactivated vaccine. Furthermore, the chimeric VLPs protected guinea pigs from FMDV challenge with an efficacy similar to that of the inactivated vaccine. These results suggest that chimeric VLPs have the potential for use in vaccines against serotype O FMDV infection. Copyright © 2015 Elsevier B.V. All rights reserved.

Surgery

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Understanding Pneumonia

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Oxygen Therapy

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Clinical and Prognostic Importance of Serotyping Mycobacterium avium-Mycobacterium intracellulare Complex Isolates in Human Immunodeficiency Virus-Negative Patients

PubMed Central

Maekura, Ryoji; Okuda, Yoshinari; Hirotani, Atsusi; Kitada, Seigo; Hiraga, Touru; Yoshimura, Kenji; Yano, Ikuya; Kobayashi, Kazuo; Ito, Masami

2005-01-01

We studied whether the serotypes of Mycobacterium avium-Mycobacterium intracellulare complex (MAC) isolates determine the prognosis for pulmonary MAC disease. We prospectively monitored a cohort of 68 patients with pulmonary MAC disease for whom the serotype-specific glycopeptidolipids in isolates were identified using thin-layer chromatography and fast atom bombardment mass-spectrometry in 1990 and 1995. Serovar 4 Mycobacterium avium was detected in 40/68 patients (58.8%). Other serotypes were serotypes 1 (five cases), 6 (three cases), 8 (seven cases), 9 (three cases), 14 (four cases), and 16 (six cases). Patients with serovar 4 were significantly (P < 0.01) younger (63.0 ± 9.8 years) than patients with other serotypes (71.8 ± 10.3). Patients who failed treatment had a significantly poorer prognosis than other patients. There were no cases of MAC-related death in the cured group. Chest radiographic findings progressively worsened in 36 (90%) of patients with serotype 4, and 14/36 died from respiratory failure caused by pulmonary Mycobacterium avium disease. The patients with serotype 4 had a significantly poorer prognosis than patients with other serotypes. These results show that both the outcome of chemotherapy and the serotypes of MAC isolates are important for assessing the prognosis of pulmonary MAC disease. PMID:16000428

Living with Tuberculosis

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Learn About Sarcoidosis

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

How Lungs Work

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Understand Your Medication

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Learn About Silicosis

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Learn About Tuberculosis

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Localization of a variational particle smoother

NASA Astrophysics Data System (ADS)

Morzfeld, M.; Hodyss, D.; Poterjoy, J.

2017-12-01

Given the success of 4D-variational methods (4D-Var) in numerical weather prediction,and recent efforts to merge ensemble Kalman filters with 4D-Var,we consider a method to merge particle methods and 4D-Var.This leads us to revisit variational particle smoothers (varPS).We study the collapse of varPS in high-dimensional problemsand show how it can be prevented by weight-localization.We test varPS on the Lorenz'96 model of dimensionsn=40, n=400, and n=2000.In our numerical experiments, weight localization prevents the collapse of the varPS,and we note that the varPS yields results comparable to ensemble formulations of 4D-variational methods,while it outperforms EnKF with tuned localization and inflation,and the localized standard particle filter.Additional numerical experiments suggest that using localized weights in varPS may not yield significant advantages over unweighted or linearizedsolutions in near-Gaussian problems.

Surface fatigue life of M50NiL and AISI 9310 spur gears and R C bars

NASA Technical Reports Server (NTRS)

Townsend, Dennis P.; Bamberger, Eric N.

1991-01-01

Spur gear endurance tests and rolling element surface fatigue tests were conducted to study vacuum induction melted, vacuum arc remelted (VIM-VAR) M50NiL steel for use as a gear steel in advanced aircraft applications, to determine its endurance characteristics, and to compare the results with those for standard VAR and VIM-VAR AISI 9310 gear material. Tests were conducted with spur gears and rolling contact bars manufactured from VIM-VAR M50NiL and VAR and VIM-VAR AISI 9310. The gear pitch diameter was 8.9 cm. Gear test conditions were an inlet oil temperature of 320 K, and outlet oil temperature of 350 K, a maximum Hertz stress of 1.71 GPa, and a speed of 10000 rpm. Bench rolling element fatigue tests were conducted at ambient temperatures with a bar speed of 12,500 rpm and a maximum Hertz stress of 4.83 GPa. The VIM-VAR M50NiL gears had a surface fatigue life that was 4.5 and 11.5 times that for VIM-VAR and VAR AISI 9310 gears, respectively. The surface fatigue life of the VIM-VAR M50NiL rolling contact bars was 13.2 and 21.6 times that for the VIM-VAR and VAR AISI 9310, respectively. The VIM-VAR M50NiL material was shown to have good resistance to fracture through a fatigue spall and superior fatigue life to both other gears.

What's in a Cigarette?

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Managing Your COPD Medications

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Group B streptococcus serotype prevalence in reproductive-age women at a tertiary care military medical center relative to global serotype distribution.

PubMed

Ippolito, Danielle L; James, Wesley A; Tinnemore, Deborah; Huang, Raywin R; Dehart, Mary J; Williams, Julie; Wingerd, Mark A; Demons, Samandra T

2010-11-24

Group B Streptococcus (GBS) serotype (Ia, Ib, II-IX) correlates with pathogen virulence and clinical prognosis. Epidemiological studies of seroprevalence are an important metric for determining the proportion of serotypes in a given population. The purpose of this study was to evaluate the prevalence of individual GBS serotypes at Madigan Healthcare System (Madigan), the largest military tertiary healthcare facility in the Pacific Northwestern United States, and to compare seroprevalences with international locations. To determine serotype distribution at Madigan, we obtained GBS isolates from standard-of-care anogenital swabs from 207 women of indeterminate gravidity between ages 18-40 during a five month interval. Serotype was determined using a recently described molecular method of polymerase chain reaction by capsular polysaccharide synthesis (cps) genes associated with pathogen virulence. Serotypes Ia, III, and V were the most prevalent (28%, 27%, and 17%, respectively). A systematic review of global GBS seroprevalence, meta-analysis, and statistical comparison revealed strikingly similar serodistibution at Madigan relative to civilian-sector populations in Canada and the United States. Serotype Ia was the only serotype consistently higher in North American populations relative to other geographic regions (p < 0.005). The number of non-typeable isolates was significantly lower in the study (p < 0.005). This study establishes PCR-based serotyping as a viable strategy for GBS epidemiological surveillance. Our results suggest that GBS seroprevalence remains stable in North America over the past two decades.

Group B streptococcus serotype prevalence in reproductive-age women at a tertiary care military medical center relative to global serotype distribution

PubMed Central

2010-01-01

Background Group B Streptococcus (GBS) serotype (Ia, Ib, II-IX) correlates with pathogen virulence and clinical prognosis. Epidemiological studies of seroprevalence are an important metric for determining the proportion of serotypes in a given population. The purpose of this study was to evaluate the prevalence of individual GBS serotypes at Madigan Healthcare System (Madigan), the largest military tertiary healthcare facility in the Pacific Northwestern United States, and to compare seroprevalences with international locations. Methods To determine serotype distribution at Madigan, we obtained GBS isolates from standard-of-care anogenital swabs from 207 women of indeterminate gravidity between ages 18-40 during a five month interval. Serotype was determined using a recently described molecular method of polymerase chain reaction by capsular polysaccharide synthesis (cps) genes associated with pathogen virulence. Results Serotypes Ia, III, and V were the most prevalent (28%, 27%, and 17%, respectively). A systematic review of global GBS seroprevalence, meta-analysis, and statistical comparison revealed strikingly similar serodistibution at Madigan relative to civilian-sector populations in Canada and the United States. Serotype Ia was the only serotype consistently higher in North American populations relative to other geographic regions (p < 0.005). The number of non-typeable isolates was significantly lower in the study (p < 0.005). Conclusion This study establishes PCR-based serotyping as a viable strategy for GBS epidemiological surveillance. Our results suggest that GBS seroprevalence remains stable in North America over the past two decades. PMID:21106080

[Serotype and phage type distribution of human Salmonella strains isolated in Spain, 1997-2001].

PubMed

Echeita, María Aurora; Aladueña, Ana María; Díez, Rosa; Arroyo, Margarita; Cerdán, Francisca; Gutiérrez, Rafaela; de la Fuente, Manuela; González-Sanz, Rubén; Herrera-León, Silvia; Usera, Miguel Angel

2005-03-01

Salmonellosis is one of the most frequent causes of gastroenteritis in Spain. Serotyping is the gold standard epidemiological marker for subdividing Salmonella spp. strains. A small number of serotypes are very frequently isolated, reducing the discriminatory power of serotyping. Thus, to increase our knowledge of Salmonella spp. epidemiology, additional epidemiological markers, such as phage typing, should be used for this purpose. Salmonella spp. strains of human origin sent to the Laboratorio Nacional de Referencia de Salmonella y Shigella (LNRSSE, Spanish Reference Laboratory for Salmonella and Shigella) between 1997 and 2001 were serotyped using conventional agglutination methods, and Enteritidis, Typhimurium, Hadar, Virchow and Typhi serotypes were additionally phage typed according to internationally-developed schemes. A total of 30,856 Salmonella spp. strains, isolated in the majority of Spanish Autonomous Communities, were analyzed. Enteritidis (51%) and Typhimurium (24%) were the most frequently isolated serotypes. The following were the most frequent serotype/phage type combinations: Enteritidis/PT1 (18%), Enteritidis/PT4 (15%), Enteritidis/PT6a (5%), Typhimurium/DT104 (5%) and Enteritidis/PT6 (3%). The serotype Enteritidis/PT1 showed the greatest increase over the period studied, from 11.61% in 1997 to 24.74% in 2001. A hierarchical typing approach for Salmonella spp., using serotyping coupled with phage typing allowed a higher level of discrimination among Salmonella serotypes. Application of this approach in epidemiological studies could be highly useful for early characterization of related strains.

Comparison of traditional culture and molecular qPCR for detection of simultaneous carriage of multiple pneumococcal serotypes in African children.

PubMed

Olwagen, Courtney P; Adrian, Peter V; Madhi, Shabir A

2017-07-05

S. pneumoniae is a common colonizer of the human nasopharynx in high income and low-middle income countries. Due to limitations of standard culture methods, the prevalence of concurrent colonization with multiple serotypes is unclear. We evaluated the use of multiplex quantitative PCR (qPCR) to detect multiple pneumococcal serotypes/group colonization in archived nasopharyngeal swabs of pneumococcal conjugate vaccine naive children who had previously been investigated by traditional culture methods. Overall the detection of pneumococcal colonization was higher by qPCR (82%) compared to standard culture (71%; p < 0.001), with a high concordance (kappa = 0.73) of serotypes/groups identified by culture also being identified by qPCR. Also, qPCR was more sensitive in detecting multiple serotype/groups among colonized cases (28.7%) compared to culture (4.5%; p < 0.001). Of the additional serotypes detected only by qPCR, the majority were of lower density (<10 4 CFU/ml) than the dominant colonizing serotype, with serotype/group 6A/B, 19B/F and 23F being the highest density colonizers, followed by serotype 5 and serogroup 9A/L/N/V being the most common second and third colonizers respectively. The ability of qPCR to detect multiple pneumococcal serotypes at a low carriage density might provide better insight into underlying mechanism for changes in serotype colonization in PCV vaccinated children.

A DNA microarray-based assay to detect dual infection with two dengue virus serotypes.

PubMed

Díaz-Badillo, Alvaro; Muñoz, María de Lourdes; Perez-Ramirez, Gerardo; Altuzar, Victor; Burgueño, Juan; Mendoza-Alvarez, Julio G; Martínez-Muñoz, Jorge P; Cisneros, Alejandro; Navarrete-Espinosa, Joel; Sanchez-Sinencio, Feliciano

2014-04-25

Here; we have described and tested a microarray based-method for the screening of dengue virus (DENV) serotypes. This DNA microarray assay is specific and sensitive and can detect dual infections with two dengue virus serotypes and single-serotype infections. Other methodologies may underestimate samples containing more than one serotype. This technology can be used to discriminate between the four DENV serotypes. Single-stranded DNA targets were covalently attached to glass slides and hybridised with specific labelled probes. DENV isolates and dengue samples were used to evaluate microarray performance. Our results demonstrate that the probes hybridized specifically to DENV serotypes; with no detection of unspecific signals. This finding provides evidence that specific probes can effectively identify single and double infections in DENV samples.

A DNA Microarray-Based Assay to Detect Dual Infection with Two Dengue Virus Serotypes

PubMed Central

Díaz-Badillo, Alvaro; de Lourdes Muñoz, María; Perez-Ramirez, Gerardo; Altuzar, Victor; Burgueño, Juan; Mendoza-Alvarez, Julio G.; Martínez-Muñoz, Jorge P.; Cisneros, Alejandro; Navarrete-Espinosa, Joel; Sanchez-Sinencio, Feliciano

2014-01-01

Here; we have described and tested a microarray based-method for the screening of dengue virus (DENV) serotypes. This DNA microarray assay is specific and sensitive and can detect dual infections with two dengue virus serotypes and single-serotype infections. Other methodologies may underestimate samples containing more than one serotype. This technology can be used to discriminate between the four DENV serotypes. Single-stranded DNA targets were covalently attached to glass slides and hybridised with specific labelled probes. DENV isolates and dengue samples were used to evaluate microarray performance. Our results demonstrate that the probes hybridized specifically to DENV serotypes; with no detection of unspecific signals. This finding provides evidence that specific probes can effectively identify single and double infections in DENV samples. PMID:24776933

Facts about the Common Cold

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Diagnosing and Treating Acute Bronchitis

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Warning Signs of Lung Disease

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Antigenic relatedness of glucosyltransferase enzymes from streptococcus mutans.

PubMed

Smith, D J; Taubman, M A

1977-01-01

The antigenic relationship of glucosyltransferases (GTF) produced by different serotypes of Streptococcus mutans was studied by using a functional inhibition assay. Rat, rabbit, or hamster immune fluids, directed to cell-associated or supernatant-derived GTF, were tested against ammonium sulfate-precipitated culture supernatants containing GTF from seven strains of S. mutans representing six different serotypes. An antigenic relationship was shown to exist among GTF from serotypes a, d, and g, since both rat and rabbit antisera directed to serotype a or g GTF inhibited GTF of serotypes d and g similarly and both antisera also inhibited serotype a GTF. Furthermore, serum inhibition patterns indicated that GTF of serotypes c and e, and possibly b, are antigenically related to each other, but are antigenically distinct from GTF of serotype a, d, or g. Serum antibody directed to antigens other than enzyme (e.g., serotype-specific antigen or teichoic acid) had little effect on the inhibition assay. Salivas from rats immunized with cell-associated or supernatant-derived GTF exhibited low but consistent inhibition of GTF activity, which generally corresponded to the serum patterns. The sera of two groups of hamsters immunized with GTF (serotype g), enriched either in water-insoluble or water-soluble glucan synthetic activity, gave patterns of inhibition quite similar to those seen with sera from more heterogenous cell-associated or crude supernatant-derived GTF preparations. Both groups of hamster sera also gave virtually identical patterns, suggesting that the two enzyme forms used as antigen share common antigenic determinants. The results from the three animal models suggest that among the cariogenic organisms tested, two (serotypes a, d, g and b, c, e), or perhaps three (serotypes a, d, g; b; and c, e), different subsets of GTF exist that have distinct antigenic determinants within a subset.

Comparative study of invertases of Streptococcus mutans.

PubMed

Tanzer, J M; Brown, A T; McInerney, M F; Woodiel, F N

1977-04-01

Sucrase activity was studied in 13 strains of Streptococcus mutans representing the five Bratthall serotypes. Sucrose-adapted cells have sucrase activity in the 37,000 x g-soluble fraction of all strains. The enzyme was identified as invertase (beta-d-fructofuranoside fructohydrolase; EC 3.2.1.26) because it hydrolyzed the beta-fructofuranoside trisaccharide raffinose, giving fructose and melibiose as its products, and because it hydrolyzed the beta-fructofuranoside dissacharide sucrose, giving equimolar glucose and fructose as its products. Invertases of c and e strains exhibit two activity peaks by molecular exclusion chromatography with molecular weights of 45,000 to 50,000 and about 180,000; those of serotypes a, b, and d strains exhibit only a single component of 45,000 to 50,000 molecular weight. The electrophoretic mobility of invertases is different between the serotypes and the same within them. Inorganic orthophosphate (P(i)) has a weak positive effect on the V(max) of invertases of serotypes c and e cells but a strong positive effect on the invertases of serotype b cells; P(i) has a strong positive effect on the apparent K(m) of the invertases of serotype d cells, but has no effect on the V(max); P(i) has a strong positive effect on both the apparent K(m) and V(max) of the invertases of serotype a cells. Thus, the invertases were different between all of the serotypes but similar within the serotypes. These findings support the taxonomic schemes of Coykendall and of Bratthall. It was additionally noted that 37,000 x g-soluble fractions of only serotypes b and c but not serotypes a, d, and e cells have melibiase activity, and it could be deduced that serotype d cells lack an intact raffinose permease system.

Clinical and microbiological characterization of serotype 6D pneumococcal infections in South Korea.

PubMed

Cheong, Hee Jin; Song, Joon Young; Choi, Min Joo; Jeon, Ji Ho; Kang, Seong Hee; Jeong, Eun Joo; Noh, Ji Yun; Kim, Woo Joo

2016-08-01

The prevalence of Serotype 6D Streptococcus pneumoniae was reported relatively high in South Korea. Since the introduction of 7-valent pneumococcal conjugate vaccine (PCV7), serotype replacement was observed. This study was designed to better clarify genetic diversity of pneumococcal serotype 6D and its clinical characteristics after introduction of PCV7 in 2000. We performed serotyping analysis with 1298 pneumococcal isolates from clinical specimens in South Korea from 2004 to 2011. Multilocus sequence typing was performed, and minimal inhibitory concentration was determined for the available serotype 6D and nontypeable (NT) pneumococcal isolates during the 2006-2007 period. The proportion of serotype 6D pneumococci increased from 0.8% (2004-2007) to 2.9% (2008-2011) of all clinical pneumococcal isolates, accounting for 14.9% of serogroup 6 pneumococci in South Korea. NT pneumococci markedly increased to 13.3% during 2006-2007 in advance of the increase in serotype 6D. Among the 26 available serotype 6D pneumococcal isolates, ST282 was predominant (23 isolates, 88.5%). The STs of NT pneumococci (26 isolates) were diverse, but clonal complex 271 was the dominant clone. The oral penicillin non-susceptibility rate was 92.3% (24 among 26 isolates) for both serotype 6D and NT pneumococci. The ceftriaxone non-susceptibility rates of serotype 6D and NT pneumococci were 7.7% and 3.8%, respectively. ST228(6D) strain expanded, particularly among old adults with comorbidities in South Korea. Both antibiotic and PCV7 pressure might have contributed to the selective increase of NT and serotype 6D pneumococci. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Group B streptococci causing neonatal infections in barcelona are a stable clonal population: 18-year surveillance.

PubMed

Martins, E R; Andreu, A; Correia, P; Juncosa, T; Bosch, J; Ramirez, M; Melo-Cristino, J

2011-08-01

We analyzed 212 group B streptococci (GBS) from newborns with invasive infections in the area of Barcelona, Spain, between 1992 and 2009, with the aim of documenting changes in the prevalences of serotypes, antimicrobial resistance, and genetic lineages and evaluating their associations with either early-onset disease (EOD) or late-onset disease (LOD). Serotypes III (n = 118) and Ia (n = 47) together accounted for nearly 78% of the isolates. All isolates carried an alpha or alpha-like protein gene, and specific associations between genes and serotypes, such as serotype Ib and bca, serotype II and bca, serotype III and rib, and serotype V and alp3, reflected the presence of particular genetic lineages. Macrolide resistance (14.2%) was significantly associated with serotype V. Pulsed-field gel electrophoresis (PFGE) clustering was an excellent predictor of serotype and antibiotic resistance. The combination of PFGE and multilocus sequence typing revealed a large number of genetically distinct lineages. Still, specific lineages were dominant in our collection, particularly the serotype III/ST17/rib lineage, which had enhanced potential to cause LOD. Serotype Ia was concentrated in a single PFGE cluster composed of two genetic lineages: ST23/eps and ST24/bca. The ST24/bca sublineage of serotype Ia, which is found infrequently elsewhere, may be emerging as an important cause of neonatal invasive infections in the Mediterranean region. In spite of the introduction of prophylaxis, resulting in a pronounced decline in the frequency of EOD, the study revealed a remarkably stable clonal structure of GBS causing neonatal infections in Barcelona over a period of 18 years.

Group B Streptococci Causing Neonatal Infections in Barcelona Are a Stable Clonal Population: 18-Year Surveillance▿

PubMed Central

Martins, E. R.; Andreu, A.; Correia, P.; Juncosa, T.; Bosch, J.; Ramirez, M.; Melo-Cristino, J.

2011-01-01

We analyzed 212 group B streptococci (GBS) from newborns with invasive infections in the area of Barcelona, Spain, between 1992 and 2009, with the aim of documenting changes in the prevalences of serotypes, antimicrobial resistance, and genetic lineages and evaluating their associations with either early-onset disease (EOD) or late-onset disease (LOD). Serotypes III (n = 118) and Ia (n = 47) together accounted for nearly 78% of the isolates. All isolates carried an alpha or alpha-like protein gene, and specific associations between genes and serotypes, such as serotype Ib and bca, serotype II and bca, serotype III and rib, and serotype V and alp3, reflected the presence of particular genetic lineages. Macrolide resistance (14.2%) was significantly associated with serotype V. Pulsed-field gel electrophoresis (PFGE) clustering was an excellent predictor of serotype and antibiotic resistance. The combination of PFGE and multilocus sequence typing revealed a large number of genetically distinct lineages. Still, specific lineages were dominant in our collection, particularly the serotype III/ST17/rib lineage, which had enhanced potential to cause LOD. Serotype Ia was concentrated in a single PFGE cluster composed of two genetic lineages: ST23/eps and ST24/bca. The ST24/bca sublineage of serotype Ia, which is found infrequently elsewhere, may be emerging as an important cause of neonatal invasive infections in the Mediterranean region. In spite of the introduction of prophylaxis, resulting in a pronounced decline in the frequency of EOD, the study revealed a remarkably stable clonal structure of GBS causing neonatal infections in Barcelona over a period of 18 years. PMID:21697333

Streptococcus pneumoniae serotype 19A in Latin America and the Caribbean: a systematic review and meta-analysis, 1990–2010

PubMed Central

2012-01-01

Background Pneumococcal conjugate vaccines (PCVs) are in the process of implementation in Latin America. Experience in developed countries has shown that they reduce the incidence of invasive and non-invasive disease. However, there is evidence that the introduction of PCVs in universal mass vaccination programs, combined with inappropriate and extensive use of antibiotics, could be associated to changes in non-PCV serotypes, including serotype 19A. We conducted a systematic review to determine the distribution of serotype 19A, burden of pneumococcal disease and antibiotic resistance in the region. Methods We performed a systematic review of serotype 19A data from observational and randomized clinical studies in the region, conducted between 1990 and 2010, for children under 6 years. Pooled prevalence estimates from surveillance activities with confidence intervals were calculated. Results We included 100 studies in 22 countries and extracted data from 63. These data reported 19733 serotyped invasive pneumococcal isolates, 3.8% of which were serotype 19A. Serotype 19A isolates were responsible for 2.4% acute otitis media episodes, and accounted for 4.1% and 4.4% of 4,380 nasopharyngeal isolates from healthy children and in hospital-based/sick children, respectively. This serotype was stable over the twenty years of surveillance in the region. A total of 53.7% Spn19A isolates from meningitis cases and only 14% from non meningitis were resistant to penicillin. Conclusions Before widespread PCV implementation in this region, serotype 19A was responsible for a relatively small number of pneumococcal disease cases. With increased use of PCVs and a greater number of serotypes included, monitoring S. pneumoniae serotype distribution will be essential for understanding the epidemiology of pneumococcal disease. PMID:22639955

Serotypes and Clonal Diversity of Streptococcus pneumoniae Causing Invasive Disease in the Era of PCV13 in Catalonia, Spain

PubMed Central

del Amo, Eva; Esteva, Cristina; Hernandez-Bou, Susanna; Galles, Carmen; Navarro, Marian; Sauca, Goretti; Diaz, Alvaro; Gassiot, Paula; Marti, Carmina; Larrosa, Nieves; Ciruela, Pilar; Jane, Mireia; Sá-Leão, Raquel; Muñoz-Almagro, Carmen

2016-01-01

The aim of this study was to study the serotypes and clonal diversity of pneumococci causing invasive pneumococcal disease in Catalonia, Spain, in the era of 13-valent pneumococcal conjugate vaccine (PCV13). In our region, this vaccine is only available in the private market and it is estimated a PCV13 vaccine coverage around 55% in children. A total of 1551 pneumococcal invasive isolates received between 2010 and 2013 in the Molecular Microbiology Department at Hospital Sant Joan de Déu, Barcelona, were included. Fifty-two serotypes and 249 clonal types—defined by MLST—were identified. The most common serotypes were serotype 1 (n = 182; 11.7%), 3 (n = 145; 9.3%), 19A (n = 137; 8.8%) and 7F (n = 122; 7.9%). Serotype 14 was the third most frequent serotype in children < 2 years (15 of 159 isolates). PCV7 serotypes maintained their proportion along the period of study, 16.6% in 2010 to 13.4% in 2013, whereas there was a significant proportional decrease in PCV13 serotypes, 65.3% in 2010 to 48.9% in 2013 (p<0.01). This decrease was mainly attributable to serotypes 19A and 7F. Serotype 12F achieved the third position in 2013 (n = 22, 6.4%). The most frequent clonal types found were ST306 (n = 154, 9.9%), ST191 (n = 111, 7.2%), ST989 (n = 85, 5.5%) and ST180 (n = 80, 5.2%). Despite their decrease, PCV13 serotypes continue to be a major cause of disease in Spain. These results emphasize the need for complete PCV13 vaccination. PMID:26953887

A comparison of machine learning and Bayesian modelling for molecular serotyping.

PubMed

Newton, Richard; Wernisch, Lorenz

2017-08-11

Streptococcus pneumoniae is a human pathogen that is a major cause of infant mortality. Identifying the pneumococcal serotype is an important step in monitoring the impact of vaccines used to protect against disease. Genomic microarrays provide an effective method for molecular serotyping. Previously we developed an empirical Bayesian model for the classification of serotypes from a molecular serotyping array. With only few samples available, a model driven approach was the only option. In the meanwhile, several thousand samples have been made available to us, providing an opportunity to investigate serotype classification by machine learning methods, which could complement the Bayesian model. We compare the performance of the original Bayesian model with two machine learning algorithms: Gradient Boosting Machines and Random Forests. We present our results as an example of a generic strategy whereby a preliminary probabilistic model is complemented or replaced by a machine learning classifier once enough data are available. Despite the availability of thousands of serotyping arrays, a problem encountered when applying machine learning methods is the lack of training data containing mixtures of serotypes; due to the large number of possible combinations. Most of the available training data comprises samples with only a single serotype. To overcome the lack of training data we implemented an iterative analysis, creating artificial training data of serotype mixtures by combining raw data from single serotype arrays. With the enhanced training set the machine learning algorithms out perform the original Bayesian model. However, for serotypes currently lacking sufficient training data the best performing implementation was a combination of the results of the Bayesian Model and the Gradient Boosting Machine. As well as being an effective method for classifying biological data, machine learning can also be used as an efficient method for revealing subtle biological insights, which we illustrate with an example.

Learn about Respiratory Syncytial Virus (RSV)

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Symptoms, Diagnosis and Treatment of Pneumonia

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

75 FR 78932 - Federal Seed Act Regulations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-17

....'', ``Broccoli-- Brassica oleracea L. var. botrytis L.'', ``Brussels sprouts--Brassica oleracea L. var. gemmifera...--Vicia faba L. var. faba'', ``Broccoli-- Brassica oleracea L. var. italica Plenck'', ``Brussels sprouts...

40 CFR 80.170 - Volumetric additive reconciliation (VAR), equipment calibration, and recordkeeping requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., the preceding twelve months of VAR formula records plus the preceding two months of VAR supporting... request, the preceding two months of VAR formula records and VAR supporting documentation. (3) Facilities... accurately and separately measured, either through the use of a separate storage tank, a separate meter, or...

40 CFR 80.170 - Volumetric additive reconciliation (VAR), equipment calibration, and recordkeeping requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., the preceding twelve months of VAR formula records plus the preceding two months of VAR supporting... request, the preceding two months of VAR formula records and VAR supporting documentation. (3) Facilities... accurately and separately measured, either through the use of a separate storage tank, a separate meter, or...

40 CFR 80.170 - Volumetric additive reconciliation (VAR), equipment calibration, and recordkeeping requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., the preceding twelve months of VAR formula records plus the preceding two months of VAR supporting... request, the preceding two months of VAR formula records and VAR supporting documentation. (3) Facilities... accurately and separately measured, either through the use of a separate storage tank, a separate meter, or...

40 CFR 80.170 - Volumetric additive reconciliation (VAR), equipment calibration, and recordkeeping requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., the preceding twelve months of VAR formula records plus the preceding two months of VAR supporting... request, the preceding two months of VAR formula records and VAR supporting documentation. (3) Facilities... accurately and separately measured, either through the use of a separate storage tank, a separate meter, or...

40 CFR 80.170 - Volumetric additive reconciliation (VAR), equipment calibration, and recordkeeping requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., the preceding twelve months of VAR formula records plus the preceding two months of VAR supporting... request, the preceding two months of VAR formula records and VAR supporting documentation. (3) Facilities... accurately and separately measured, either through the use of a separate storage tank, a separate meter, or...

The genetic organization of the capsular polysaccharide biosynthesis region of Actinobacillus pleuropneumoniae serotype 14

PubMed Central

ITO, Hiroya

2015-01-01

The genetic organization of the gene involved in the capsular polysaccharide (CPS) biosynthesis of Actinobacillus pleuropneumoniae serotype 14 has been determined. The DNA region for the CPS biosynthesis of serotype 14 (cps14) comprised 9 open reading frames, designated as cps14AB1B2B3CDEFG genes, encoding Cps14A to Cps14G protein, respectively. Cps14A was similar to CpsA of A. pleuropneumoniae serotypes 1, 4 and 12; the Cps14B1 and Cps14B2 were similar to CpsB of A. pleuropneumoniae serotypes 1, 4 and 12, suggesting that CPS structure of A. pleuropneumoniae serotype 14 would belong to Group I including A. pleuropneumoniae serotypes 1, 4, 12 and 15. Surprisingly, the overall nucleotide sequence, deduced amino acid sequence, and the genetic organization of the cps14 were nearly identical to those of Actinobacillus suis. This study will provide the molecular basic knowledge for development of diagnostics and vaccine of A. pleuropneumoniae serotype 14. PMID:25648373

Nontuberculous Mycobacterium Infections: Symptoms, Causes & Risk Factors

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

The PneuCarriage Project: A Multi-Centre Comparative Study to Identify the Best Serotyping Methods for Examining Pneumococcal Carriage in Vaccine Evaluation Studies.

PubMed

Satzke, Catherine; Dunne, Eileen M; Porter, Barbara D; Klugman, Keith P; Mulholland, E Kim

2015-11-01

The pneumococcus is a diverse pathogen whose primary niche is the nasopharynx. Over 90 different serotypes exist, and nasopharyngeal carriage of multiple serotypes is common. Understanding pneumococcal carriage is essential for evaluating the impact of pneumococcal vaccines. Traditional serotyping methods are cumbersome and insufficient for detecting multiple serotype carriage, and there are few data comparing the new methods that have been developed over the past decade. We established the PneuCarriage project, a large, international multi-centre study dedicated to the identification of the best pneumococcal serotyping methods for carriage studies. Reference sample sets were distributed to 15 research groups for blinded testing. Twenty pneumococcal serotyping methods were used to test 81 laboratory-prepared (spiked) samples. The five top-performing methods were used to test 260 nasopharyngeal (field) samples collected from children in six high-burden countries. Sensitivity and positive predictive value (PPV) were determined for the test methods and the reference method (traditional serotyping of >100 colonies from each sample). For the alternate serotyping methods, the overall sensitivity ranged from 1% to 99% (reference method 98%), and PPV from 8% to 100% (reference method 100%), when testing the spiked samples. Fifteen methods had ≥70% sensitivity to detect the dominant (major) serotype, whilst only eight methods had ≥70% sensitivity to detect minor serotypes. For the field samples, the overall sensitivity ranged from 74.2% to 95.8% (reference method 93.8%), and PPV from 82.2% to 96.4% (reference method 99.6%). The microarray had the highest sensitivity (95.8%) and high PPV (93.7%). The major limitation of this study is that not all of the available alternative serotyping methods were included. Most methods were able to detect the dominant serotype in a sample, but many performed poorly in detecting the minor serotype populations. Microarray with a culture amplification step was the top-performing method. Results from this comprehensive evaluation will inform future vaccine evaluation and impact studies, particularly in low-income settings, where pneumococcal disease burden remains high.

The PneuCarriage Project: A Multi-Centre Comparative Study to Identify the Best Serotyping Methods for Examining Pneumococcal Carriage in Vaccine Evaluation Studies

PubMed Central

Satzke, Catherine; Dunne, Eileen M.; Porter, Barbara D.; Klugman, Keith P.; Mulholland, E. Kim

2015-01-01

Background The pneumococcus is a diverse pathogen whose primary niche is the nasopharynx. Over 90 different serotypes exist, and nasopharyngeal carriage of multiple serotypes is common. Understanding pneumococcal carriage is essential for evaluating the impact of pneumococcal vaccines. Traditional serotyping methods are cumbersome and insufficient for detecting multiple serotype carriage, and there are few data comparing the new methods that have been developed over the past decade. We established the PneuCarriage project, a large, international multi-centre study dedicated to the identification of the best pneumococcal serotyping methods for carriage studies. Methods and Findings Reference sample sets were distributed to 15 research groups for blinded testing. Twenty pneumococcal serotyping methods were used to test 81 laboratory-prepared (spiked) samples. The five top-performing methods were used to test 260 nasopharyngeal (field) samples collected from children in six high-burden countries. Sensitivity and positive predictive value (PPV) were determined for the test methods and the reference method (traditional serotyping of >100 colonies from each sample). For the alternate serotyping methods, the overall sensitivity ranged from 1% to 99% (reference method 98%), and PPV from 8% to 100% (reference method 100%), when testing the spiked samples. Fifteen methods had ≥70% sensitivity to detect the dominant (major) serotype, whilst only eight methods had ≥70% sensitivity to detect minor serotypes. For the field samples, the overall sensitivity ranged from 74.2% to 95.8% (reference method 93.8%), and PPV from 82.2% to 96.4% (reference method 99.6%). The microarray had the highest sensitivity (95.8%) and high PPV (93.7%). The major limitation of this study is that not all of the available alternative serotyping methods were included. Conclusions Most methods were able to detect the dominant serotype in a sample, but many performed poorly in detecting the minor serotype populations. Microarray with a culture amplification step was the top-performing method. Results from this comprehensive evaluation will inform future vaccine evaluation and impact studies, particularly in low-income settings, where pneumococcal disease burden remains high. PMID:26575033

Impact of Ten-Valent Pneumococcal Conjugate Vaccine Introduction on Serotype Distribution Trends in Colombia: An Interrupted Time-Series Analysis

PubMed Central

Leal, Aura Lucia; Montañez, Anita Maria; Buitrago, Giancarlo; Patiño, Jaime; Camacho, German; Moreno, Vivian Marcela; Colombia, Red Neumo

2017-01-01

Abstract Background Trends in distribution of S. pneumoniae capsular serotypes are associated with the introduction of pneumococcal conjugate vaccines (PCV) among population. In Colombia, 10-valent PCV (PCV10) has been included in the national vaccination program since 2011. As a part of the pneumococcal surveillance network (SIREVA), Colombia has gathered data of serotype distribution since 1993. The aim of this work is to determine the effect of PCV10 introduction on non-coverage serotypes by PCV10 in Colombia, specifically, the effect on 6A, 19A and 3 serotypes. Methods Information was obtained from the national surveillance program since 1993 to 2016 in children under 5 years. The isolates came from sterile sites (blood, cerebrospinal fluid, pleural fluid, articular and peritoneal fluids). All the isolates were serotyping by National Institute of Health. An interrupted time series analysis was performed to determine the effect of the PCV10 introduction on the 6A, 19A and 3 serotypes (ARIMA model). Results Serotyping was performed in 4683 isolates. The annual proportion trend of the 6A, 19A and 3 serotypes remained constant until 2012. An increase of double in the serotype proportion trends was observed after 2012 (Figure). The interrupted time-series analysis showed a positive effect of the PCV10 introduction on trends of 19A and 3 serotypes, with coefficients 20.92 (P = 0.00, ARIMA(2,0,1)) and 6.32 (P = 0.00, ARIMA(2,1,1), respectively. There was no significant effect on 6A serotype trend. Conclusion The introduction of PCV10 in the national vaccination program in Colombia, affected the distribution of PVC 13 capsular types non included in the PCV 7 and PCV 10 in children under 5 years. This information emphasizes the importance to surveillance the changes in serotype distributions to guide prevention strategies in children under 5 years in Colombia. Figure. 1 Trends in distribution of serotypes 19A, 3 and 6A in children under 5 years. Colombia. Disclosures All authors: No reported disclosures.

Murine Model for Preclinical Studies of Var2CSA-Mediated Pathology Associated with Malaria in Pregnancy

PubMed Central

Dechavanne, Sebastien; Sousa, Patrícia M.; Barateiro, André; Cunha, Sónia F.; Nunes-Silva, Sofia; Lima, Flávia A.; Murillo, Oscar; Marinho, Claudio R. F.; Gangnard, Stephane; Srivastava, Anand; Braks, Joanna A.; Janse, Chris J.; Gamain, Benoit; Penha-Gonçalves, Carlos

2016-01-01

Plasmodium falciparum infection during pregnancy leads to abortions, stillbirth, low birth weight, and maternal mortality. Infected erythrocytes (IEs) accumulate in the placenta by adhering to chondroitin sulfate A (CSA) via var2CSA protein exposed on the P. falciparum IE membrane. Plasmodium berghei IE infection in pregnant BALB/c mice is a model for severe placental malaria (PM). Here, we describe a transgenic P. berghei parasite expressing the full-length var2CSA extracellular region (domains DBL1X to DBL6ε) fused to a P. berghei exported protein (EMAP1) and characterize a var2CSA-based mouse model of PM. BALB/c mice were infected at midgestation with different doses of P. berghei-var2CSA (P. berghei-VAR) or P. berghei wild-type IEs. Infection with 104 P. berghei-VAR IEs induced a higher incidence of stillbirth and lower fetal weight than P. berghei. At doses of 105 and 106 IEs, P. berghei-VAR-infected mice showed increased maternal mortality during pregnancy and fetal loss, respectively. Parasite loads in infected placentas were similar between parasite lines despite differences in maternal outcomes. Fetal weight loss normalized for parasitemia was higher in P. berghei-VAR-infected mice than in P. berghei-infected mice. In vitro assays showed that higher numbers of P. berghei-VAR IEs than P. berghei IEs adhered to placental tissue. Immunization of mice with P. berghei-VAR elicited IgG antibodies reactive to DBL1-6 recombinant protein, indicating that the topology of immunogenic epitopes is maintained between DBL1-6–EMAP1 on P. berghei-VAR and recombinant DBL1-6 (recDBL1-6). Our data suggested that impairments in pregnancy caused by P. berghei-VAR infection were attributable to var2CSA expression. This model provides a tool for preclinical evaluation of protection against PM induced by approaches that target var2CSA. PMID:27045035

PCR-Restriction Fragment Length Polymorphism Analysis of the Phospholipase B (PLB1) Gene for Subtyping of Cryptococcus neoformans Isolates

PubMed Central

Latouche, G. Nicolas; Huynh, Matthew; Sorrell, Tania C.; Meyer, Wieland

2003-01-01

Cryptococcus neoformans is a pathogenic yeast that is currently divided into three varieties, five serotypes, and eight molecular types. The following report describes the use of PCR-restriction fragment length polymorphism (RFLP) analysis of the phospholipase B gene (PLB1) as a simple tool to differentiate between C. neoformans subgroups. A PLB1 fragment, 1,970 bp, was amplified and digested with either AvaI or HindIII. Both sets of profiles grouped the isolates into their respective varieties, but only the AvaI profiles allowed for the identification of the eight molecular types via the corresponding RFLP profiles A1 to A8. Digestion of the same fragments with HindIII resulted in RFLP profiles H1 to H5, which distinguished only between serotype A, AD, D, and B/C. Neither enzyme distinguished serotype B from serotype C. The serotype AD profile was a composite of the serotype A and D profiles. Further investigation showed that the serotype AD isolates used in this study are heterozygous, with one allele of PLB1 originating from a serotype A parent and the other from a serotype D parent. PMID:12676686

Genetic relationships and clonal population structure of serotype 2 strains of Neisseria meningitidis.

PubMed Central

Caugant, D A; Zollinger, W D; Mocca, L F; Frasch, C E; Whittam, T S; Frøholm, L O; Selander, R K

1987-01-01

Two hundred and thirty-four strains of Neisseria meningitidis, including 94 serotype 2a, 111 serotype 2b, and 19 serotype 2c isolates, together with 10 isolates that were serotyped as 2 with polyvalent antiserum but did not react with monoclonal antibodies, were characterized by the electrophoretic mobilities of 15 metabolic enzymes. Of these enzymes, 14 were polymorphic, and 56 distinctive combinations of alleles at the enzyme loci (electrophoretic types) were identified, among which the mean genetic diversity per locus was 0.413, or about 75% of that recorded for the species N. meningitidis as a whole. Mean genetic diversity among electrophoretic types of the same serotype (2a, 2b, or 2c) was, however, on average, less than half the total species diversity, and no multilocus genotypes were shared between isolates of the different serotypes, which belong to distinctive clonal lineages. Recent temporal changes in the frequencies of recovery of pathogenic strains of serotypes 2a and 2b in South Africa and North America resulted from clone replacement in these populations rather than evolutionary modification of the serotype protein of the initially dominant clones. PMID:3106223

Molecular serotyping, virulence gene profiling and pathogenicity of Streptococcus agalactiae isolated from tilapia farms in Thailand by multiplex PCR.

PubMed

Kannika, K; Pisuttharachai, D; Srisapoome, P; Wongtavatchai, J; Kondo, H; Hirono, I; Unajak, S; Areechon, N

2017-06-01

This study aimed to biotype Streptococcus agalactiae isolated from tilapia farms in Thailand based on molecular biotyping methods and to determine the correlation between the serotype and virulence of bacteria. In addition to a biotyping (serotyping) technique based on multiplex PCR of cps genes, in this study, we developed multiplex PCR typing of Group B streptococcus (GBS) virulence genes to examine three clusters of virulence genes and their correlation with the pathogenicity of S. agalactiae. The epidemiology of S. agalactiae in Thailand was analysed to provide bacterial genetic information towards a future rational vaccine strategy for tilapia culture systems. Streptococcus agalactiae were isolated from diseased tilapia from different areas of Thailand. A total of 124 S. agalactiae isolates were identified by phenotypic analysis and confirmed by 16S rRNA PCR. Bacterial genotyping was conducted based on (i) molecular serotyping of the capsular polysaccharide (cps) gene cluster and (ii) virulence gene profiling using multiplex PCR analysis of 14 virulence genes (lmb, scpB, pavA, cspA, spb1, cyl, bca, rib, fbsA, fbsB, cfb, hylB, bac and pbp1A/ponA). Only serotypes Ia and III were found in this study; serotype Ia lacks the lmb, scpB and spb1 genes, whereas serotype III lacks only the bac gene. Virulence tests in juvenile Nile tilapia demonstrated a correlation between the pathogenicity of the bacteria and their virulence gene profile, with serotype III showing higher virulence than serotype Ia. Epidemiological analysis showed an almost equal distribution in all regions of Thailand, except serotype III was found predominantly in the southern areas. Only two serotypes of S. agalactiae were isolated from diseased tilapia in Thailand. Serotype Ia showed fewer virulence genes and lower virulence than serotype III. Both serotypes showed a similar distribution throughout Thailand. We identified two major serotypes of S. agalactiae isolates associated with the outbreak in tilapia culture in Thailand. We developed multiplex PCR assays for 14 virulence genes, which may be used to predict the pathogenicity of the isolates and track future infections. Multiplex PCR typing of the GBS virulence genes was developed and might be further used to predict the pathogenicity of S. agalactiae. © 2017 The Society for Applied Microbiology.

What is Multidrug and Extensively Drug Resistant TB?

MedlinePlus

... each(function(i){ var city = $(this).find('city').text(); var state = $(this).find('state').text(); var date = $(this).find('date').text(); if ((city != "") && (state != "")){ var citystate = ' | ' + city + ', ' + state; } else ...

Detoxification of Benzoxazolinone Allelochemicals from Wheat by Gaeumannomyces graminis var. tritici, G. graminis var. graminis, G. graminis var. avenae, and Fusarium culmorum

PubMed Central

Friebe, A.; Vilich, V.; Hennig, L.; Kluge, M.; Sicker, D.

1998-01-01

The ability of phytopathogenic fungi to overcome the chemical defense barriers of their host plants is of great importance for fungal pathogenicity. We studied the role of cyclic hydroxamic acids and their related benzoxazolinones in plant interactions with pathogenic fungi. We identified species-dependent differences in the abilities of Gaeumannomyces graminis var. tritici, Gaeumannomyces graminis var. graminis, Gaeumannomyces graminis var. avenae, and Fusarium culmorum to detoxify these allelochemicals of gramineous plants. The G. graminis var. graminis isolate degraded benzoxazolin-2(3H)-one (BOA) and 6-methoxy-benzoxazolin-2(3H)-one (MBOA) more efficiently than did G. graminis var. tritici and G. graminis var. avenae. F. culmorum degraded BOA but not MBOA. N-(2-Hydroxyphenyl)-malonamic acid and N-(2-hydroxy-4-methoxyphenyl)-malonamic acid were the primary G. graminis var. graminis and G. graminis var. tritici metabolites of BOA and MBOA, respectively, as well as of the related cyclic hydroxamic acids. 2-Amino-3H-phenoxazin-3-one was identified as an additional G. graminis var. tritici metabolite of BOA. No metabolite accumulation was detected for G. graminis var. avenae and F. culmorum by high-pressure liquid chromatography. The mycelial growth of the pathogenic fungi was inhibited more by BOA and MBOA than by their related fungal metabolites. The tolerance of Gaeumannomyces spp. for benzoxazolinone compounds is correlated with their detoxification ability. The ability of Gaeumannomyces isolates to cause root rot symptoms in wheat (cultivars Rektor and Astron) parallels their potential to degrade wheat allelochemicals to nontoxic compounds. PMID:9647804

Molecular detection assay of five Salmonella serotypes of public interest: Typhimurium, Enteritidis, Newport, Heidelberg, and Hadar.

PubMed

Bugarel, M; Tudor, A; Loneragan, G H; Nightingale, K K

2017-03-01

Foodborne illnesses due to Salmonella represent an important public-health concern worldwide. In the United States, a majority of Salmonella infections are associated with a small number of serotypes. Furthermore, some serotypes that are overrepresented among human disease are also associated with multi-drug resistance phenotypes. Rapid detection of serotypes of public-health concern might help reduce the burden of salmonellosis cases and limit exposure to multi-drug resistant Salmonella. We developed a two-step real-time PCR-based rapid method for the identification and detection of five Salmonella serotypes that are either overrepresented in human disease or frequently associated with multi-drug resistance, including serotypes Enteritidis, Typhimurium, Newport, Hadar, and Heidelberg. Two sets of four markers were developed to detect and differentiate the five serotypes. The first set of markers was developed as a screening step to detect the five serotypes; whereas, the second set was used to further distinguish serotypes Heidelberg, Newport and Hadar. The utilization of these markers on a two-step investigation strategy provides a diagnostic specificity of 97% for the detection of Typhimurium, Enteritidis, Heidelberg, Infantis, Newport and Hadar. The diagnostic sensitivity of the detection makers is >96%. The availability of this two-step rapid method will facilitate specific detection of Salmonella serotypes that contribute to a significant proportion of human disease and carry antimicrobial resistance. Published by Elsevier B.V.

Serotype Distribution and Antimicrobial Resistance of Streptococcus pneumoniae Isolates from Pediatric Patients in Singapore

PubMed Central

Soh, Shirlena Wee-Ling; Poh, Chit Laa; Lin, Raymond V. Tzer Pin

2000-01-01

One hundred eighty Streptococcus pneumoniae strains isolated from children at a pediatric hospital in Singapore from 1997 to 1999 were serotyped and their antimicrobial susceptibility patterns were determined. Sixty-three percent of the isolates were resistant to penicillin. Significantly large numbers of the strains investigated were resistant to trimethoprim-sulfamethoxazole (87.8%), tetracycline (71.7%), erythromycin (67.8%), and chloramphenicol (40%). Penicillin and multidrug resistance was mostly associated with the frequently isolated S. pneumoniae isolates of serotypes (serotypes 19F, 23F, 6B, and 14). Isolates of serotype 19F, the serotype most commonly encountered in Singapore (41.1%), had the highest prevalence of penicillin (78.4%) and multidrug resistance (94.6%). Most of the invasive S. pneumoniae isolates (8 of 17; 47.1%) were of serotype 14. PMID:10898701

Serotype 3 is a common serotype causing invasive pneumococcal disease in children less than 5 years old, as identified by real-time PCR.

PubMed

Selva, L; Ciruela, P; Esteva, C; de Sevilla, M F; Codina, G; Hernandez, S; Moraga, F; García-García, J J; Planes, A; Coll, F; Jordan, I; Cardeñosa, N; Batalla, J; Salleras, L; Dominguez, A; Muñoz-Almagro, C

2012-07-01

Serotype 3 is one of the most often detected pneumococcal serotypes in adults and it is associated with serious disease. In contrast, the isolation of serotype 3 by bacterial culture is unusual in children with invasive pneumococcal disease (IPD). The purpose of this study was to learn the serotype distribution of IPD, including culture-negative episodes, by using molecular methods in normal sterile samples. We studied all children<5 years of age with IPD admitted to two paediatric hospitals in Catalonia, Spain, from 2007 to 2009. A sequential real-time polymerase chain reaction (PCR) approach was added to routine methods for the detection and serotyping of pneumococcal infection. Among 257 episodes (219 pneumonia, 27 meningitis, six bacteraemia and five others), 33.5% were identified by culture and the rest, 66.5%, were detected exclusively by real-time PCR. The most common serotypes detected by culture were serotypes 1 (26.7%) and 19A (25.6%), and by real-time PCR, serotypes 1 (19.8%) and 3 (18.1%). Theoretical coverage rates by the PCV7, PCV10 and PCV13 vaccines were 10.5, 52.3 and 87.2%, respectively, for those episodes identified by culture, compared to 5.3, 31.6 and 60.2% for those identified only by real-time PCR. Multiplex real-time PCR has been shown to be useful for surveillance studies of IPD. Serotype 3 is underdiagnosed by culture and is important in paediatric IPD.

Antigenic variation in malaria: in situ switching, relaxed and mutually exclusive transcription of var genes during intra-erythrocytic development in Plasmodium falciparum.

PubMed Central

Scherf, A; Hernandez-Rivas, R; Buffet, P; Bottius, E; Benatar, C; Pouvelle, B; Gysin, J; Lanzer, M

1998-01-01

Members of the Plasmodium falciparum var gene family encode clonally variant adhesins, which play an important role in the pathogenicity of tropical malaria. Here we employ a selective panning protocol to generate isogenic P.falciparum populations with defined adhesive phenotypes for CD36, ICAM-1 and CSA, expressing single and distinct var gene variants. This technique has established the framework for examining var gene expression, its regulation and switching. It was found that var gene switching occurs in situ. Ubiquitous transcription of all var gene variants appears to occur in early ring stages. However, var gene expression is tightly regulated in trophozoites and is exerted through a silencing mechanism. Transcriptional control is mutually exclusive in parasites that express defined adhesive phenotypes. In situ var gene switching is apparently mediated at the level of transcriptional initiation, as demonstrated by nuclear run-on analyses. Our results suggest that an epigenetic mechanism(s) is involved in var gene regulation. PMID:9736619

A comparison between EDA-EnVar and ETKF-EnVar data assimilation techniques using radar observations at convective scales through a case study of Hurricane Ike (2008)

NASA Astrophysics Data System (ADS)

Shen, Feifei; Xu, Dongmei; Xue, Ming; Min, Jinzhong

2017-07-01

This study examines the impacts of assimilating radar radial velocity (Vr) data for the simulation of hurricane Ike (2008) with two different ensemble generation techniques in the framework of the hybrid ensemble-variational (EnVar) data assimilation system of Weather Research and Forecasting model. For the generation of ensemble perturbations we apply two techniques, the ensemble transform Kalman filter (ETKF) and the ensemble of data assimilation (EDA). For the ETKF-EnVar, the forecast ensemble perturbations are updated by the ETKF, while for the EDA-EnVar, the hybrid is employed to update each ensemble member with perturbed observations. The ensemble mean is analyzed by the hybrid method with flow-dependent ensemble covariance for both EnVar. The sensitivity of analyses and forecasts to the two applied ensemble generation techniques is investigated in our current study. It is found that the EnVar system is rather stable with different ensemble update techniques in terms of its skill on improving the analyses and forecasts. The EDA-EnVar-based ensemble perturbations are likely to include slightly less organized spatial structures than those in ETKF-EnVar, and the perturbations of the latter are constructed more dynamically. Detailed diagnostics reveal that both of the EnVar schemes not only produce positive temperature increments around the hurricane center but also systematically adjust the hurricane location with the hurricane-specific error covariance. On average, the analysis and forecast from the ETKF-EnVar have slightly smaller errors than that from the EDA-EnVar in terms of track, intensity, and precipitation forecast. Moreover, ETKF-EnVar yields better forecasts when verified against conventional observations.

IkeNet: Social Network Analysis of E-mail Traffic in the Eisenhower Leadership Development Program

DTIC Science & Technology

2007-11-01

8217Create the recipients TO TempArray = Sphit(strTo,") For Each varArrayltem In TemnpArray hextGuy = Chr(34) & CStr (Trim(varArrayltem)) & Chr(34) MsgBox...34next guy = " & nextGuy ’Set oRecipient = Recipients.Add(nextGuy) Set oRecipient = Recipients.Add( CStr (Trim(varArrayItem))) oRecipient.Type = olTo...TempArray = Split(strAttachments, "" For Each varArrayltern In TempArray .Attachments.Add CStr (Trim(varArrayItem)) Next varArrayltern .Send No return value

Protein antigen in serotype k Streptococcus mutans clinical isolates.

PubMed

Nakano, K; Nomura, R; Nemoto, H; Lapirattanakul, J; Taniguchi, N; Grönroos, L; Alaluusua, S; Ooshima, T

2008-10-01

Streptococcus mutans, a major pathogen of dental caries and infective endocarditis, is classified into serotypes c, e, f, and k, with serotype k strains recently reported to be frequently detected in persons with infective endocarditis. Thus, we hypothesized that common properties associated with infective endocarditis are present in those strains. Fifty-six oral S. mutans strains, including 11 serotype k strains, were analyzed. Western blotting analysis revealed expression of the 3 types of glucosyltransferases in all strains, while expression of the approximately 190-kDa cell-surface protein (PA) was absent in 12 strains, among which the prevalence of serotype k (7/12) was significantly high. Furthermore, cellular hydrophobicity and phagocytosis susceptibility were lower in the group of serotype k strains. These results indicate that the absence of PA expression, low cellular hydrophobicity, and phagocytosis susceptibility are common bacterial properties associated with serotype k strains, which may be associated with virulence for infective endocarditis.

The genetic organization of the capsular polysaccharide biosynthesis region of Actinobacillus pleuropneumoniae serotype 15

PubMed Central

ITO, Hiroya; SUEYOSHI, Masuo

2014-01-01

Nucleotide sequence determination and analysis of the cps gene involved in the capsular polysaccharide biosynthesis of Actinobacillus pleuropneumoniae serotype 15 revealed the presence of three open reading frames, designated as cps15ABC genes. At the protein level, Cps15A and Cps15B showed considerably high homology to CpsA (67.0 to 68.7%) and CpsB (31.7 to 36.8%), respectively, of A. pleuropneumoniae serotypes 1, 4 and 12, revealing the common genetic organization of the cps among serotypes 1, 4, 12 and 15. However, Cps15C showed no homology to any proteins of A. pleuropneumoniae serotypes, indicating that cps15C may be specific to serotype 15. This study will provide the basic molecular knowledge necessary for the development of diagnostics and a vaccine for A. pleuropneumoniae serotype 15. PMID:25502540

Molecular diagnosis of non-serotypeable Shigella spp.: problems and prospects.

PubMed

Muthuirulandi Sethuvel, Dhiviya Prabaa; Devanga Ragupathi, Naveen Kumar; Anandan, Shalini; Walia, Kamini; Veeraraghavan, Balaji

2017-02-01

It is not always possible to identify Shigella serogroups/serotypes by biochemical properties alone. Specific identification requires serotyping. Occasionally, isolates that resemble Shigella spp. biochemically, but are non-agglutinable with available antisera, have been observed. Several mechanisms have been reported to limit the efficiency of the serotyping assay. Serotype conversion is a major mechanism in Shigella spp. to escape protective host immune responses. This easy conversion through significant modification of the O-antigen backbone results in different serotypes, which makes laboratory identification difficult. Furthermore, members of the family Enterobacteriaceae are closely related and there is antigenic cross-over (intra- and inter-specific cross-reaction) which affects the agglutination reaction. The performance of the available methods for identification of non-serotypeable Shigella is discussed here, and reveals them to be non-reliable. This shows a need for an alternative method for identification and typing of Shigella spp.

[Identification of rotavirus associated to serotype G2 in Yucatan, Mexico].

PubMed

Gonzales-Loza, M del R; Polanco-Marín, G G; Puerto-Solis, M

2000-01-01

In the present study, rotavirus G2 serotype was identified from fecal samples of children with gastroenteritis from the city of Merida, Yucatan, Mexico. Virological diagnosis of disease was performed using polycrylamide gel electrophoresis and immunoenzymatic assay. Out of 149 analyzed samples 25 (16.7%) gave positive reaction to rotavirus groups A, of these 23 (92%) were identified as serotype g2, subgroup i and electrophoretic short pattern, whereas 2 (8%) were identified as subgroups II and electrophoretic long pattern, however, the G serotype was not possible to determine. Rotavirus G serotype has not been detected in more than 90% of samples since 1985. This indicates that the number of people susceptible to G2 serotype within the population has increased over recent years, which perhaps indicates that an important outbreak of acute infectious diarrhea caused by the rotavirus G2 serotype may be forthcoming.

Definition of human rotavirus serotypes by plaque reduction assay.

PubMed Central

Wyatt, R G; Greenberg, H B; James, W D; Pittman, A L; Kalica, A R; Flores, J; Chanock, R M; Kapikian, A Z

1982-01-01

Twenty different human rotavirus reassortants were characterized serologically by a plaque reduction assay as belonging to one of three distinct serotypes. Fourteen were similar if not identical to our prototype Wa strain; two were like the prototype DS-1 strain, and four belonged to a third serotype for which a prototype has not yet been selected. Hyperimmune sera raised against the three serotypes were required to distinguish among them, since postinfection sera had lower titers and were more cross-reactive than hyperimmune sera. These results confirmed the ability of a qualitative cytopathic neutralization test to predict correctly the Wa or DS-1 serotype. A strain of rhesus rotavirus (MMU 18006) was identified as belonging to the newly defined third serotype. Finally, an attempt was made to correlate previously published serotype analysis by neutralization of fluorescent cell-forming units with the results determined by the plaque reduction neutralization assay. PMID:6286487

Rapid molecular pathotyping of major salmonella enterica serotypes based on single-nucleotide polymorphisms (SNPs) in the adenylate cyclase (cyaA) gene

USDA-ARS?s Scientific Manuscript database

Introduction: Salmonella enterica subsp. enterica serotype Enteriditis (S. Enteriditis) is the leading cause of salmonellosis worldwide, including the USA. Many S. enterica serotypes known to cause foodborne disease are associated with broiler meat contamination. While some serotypes are specific...

Haemophilus influenzae serotype a meningitis.

PubMed

de Pádua, Rubia Andreia Falleiros; de Lima Scodro, Regiane Bertin; Ghiraldi, Luciana Dias; Siqueira, Vera Lúcia Dias; Yamashita, Yandara Keiko; Helbel, César; Cardoso, Rosilene Fressatti

2009-01-01

This work describes a case of Haemophilus influenzae serotype a meningitis in Brazil, after almost a decade since the introduction of Haemophilus influenzae serotype b conjugate vaccine. Uncertainty about the replacement of H. influenzae serotypes as a cause of invasive diseases justifies continuous surveillance, coupled with investigations of carriage rates and requirements of chemoprophylaxis in contact persons.

Serotype changes in adult invasive pneumococcal infections in Portugal did not reduce the high fraction of potentially vaccine preventable infections.

PubMed

Horácio, Andreia N; Diamantino-Miranda, Jorge; Aguiar, Sandra I; Ramirez, Mário; Melo-Cristino, José

2012-01-05

We determined the serotype and antimicrobial susceptibility of 1100 isolates responsible for adult invasive pneumococcal infections (IPD) in Portugal between 2006 and 2008. Serotypes 3 (13%), 1 (12%), 7F (11%), 19A (10%) and 14 (7%) were the most frequent causes of IPD and the two later serotypes accounted for the majority of erythromycin and penicillin nonsusceptible isolates. Serotype 1 was associated with younger adults whereas serotype 3 was associated with older adults. Despite the availability of the 23-valent polysaccharide vaccine (PPV23) in Portugal since 1996, the proportion of PPV23 preventable IPD remained stable and above 80%. Comparing with previous data from Portugal, we showed a continued decline of the serotypes included in the 7-valent conjugate vaccine (PCV7) in adult IPD and a rise of serotypes included in the 13-valent conjugate vaccine, increasing its potential coverage of adult IPD to 70% in 2008. Penicillin non-susceptibility remained stable (17%) whereas erythromycin resistance (18%) has continued to rise in the post-PCV7 years. Copyright © 2011 Elsevier Ltd. All rights reserved.

Update on: Shigella new serogroups/serotypes and their antimicrobial resistance.

PubMed

Muthuirulandi Sethuvel, D P; Devanga Ragupathi, N K; Anandan, S; Veeraraghavan, B

2017-01-01

Shigellosis represents a major burden of disease in developing countries. A low infectious dose allows the disease to be spread effectively. Although shigellosis is mostly a self-limiting disease, antibiotics are recommended to reduce deaths, disease symptoms and organism-shedding time. However, in India, antimicrobial resistance among the genus Shigella is more common than among any other enteric bacteria. Notably, new serotypes or subserotypes in Shigella are reported from various parts of the world. Identification of new subserotypes of Shigella spp. is becoming a major issue as these strains are nontypeable by conventional serotyping. The commercially available antisera may not cover all possible epitopes of the O lipopolysaccharide antigen of Shigella serotypes. Therefore, molecular methods which most closely approach the resolution of full serotyping are necessary to identify such strains. In addition, the knowledge of a prevalent serotype in various geographic regions may assist in formulating strategies such as the development of a vaccine to prevent infection especially when the immunity to disease is serotype specific, and to understand the disease burden caused by new Shigella serotypes. © 2016 The Society for Applied Microbiology.

Taxonomic study on Japanese Salvia (Lamiaceae): Phylogenetic position of S. akiensis, and polyphyletic nature of S. lutescens var. intermedia.

PubMed

Takano, Atsuko

2017-01-01

Both Salvia akiensis and S. lutescens (Lamiaceae) are endemic to Japan. Salvia akiensis was recently described in 2014 in the Chugoku (= SW Honshu) region, and each four varieties of S. lutescens distributed allopatrically. Among varieties in S. lutescens , var. intermedia show a disjunctive distribution in the Kanto (=E Honshu) and Kinki (= W Honshu) regions. Recent field studies of S. lutescens var. intermedia revealed several morphological differences between the Kanto and Kinki populations. Here, I evaluated these differences among Salvia lutescens var. intermedia and its allies with morphological analysis and molecular phylogenetic analyses of nuclear ribosomal DNA (internal and external transcribed spacer regions) and plastid DNA ( ycf1-rps15 spacer, rbcL , and trnL-F ) sequences. Both morphological analysis and molecular phylogenetic analyses showed that S. lutescens var. intermedia from the Kinki region and var. lutescens were closely related to each other. However, var. intermedia from the Kanto region exhibited an association with S. lutescens var. crenata and var. stolonifera, which also grew in eastern Japan, rather than var. intermedia in the Kinki region. These results indicated that S. lutescens var. intermedia is not a taxon with a disjunctive distribution, but a combination of two or more allopatric taxa. Present study also suggested that S. akiensis was most closely related to S. omerocalyx .

Capsular serotypes, virulence-associated genes and antimicrobial susceptibility of Streptococcus suis isolates from pigs in Korea.

PubMed

Oh, Sang-Ik; Jeon, Albert Byungyun; Jung, Byeong-Yeal; Byun, Jae-Won; Gottschalk, Marcelo; Kim, Aeran; Kim, Jong Wan; Kim, Ha-Young

2017-04-20

Streptococcus suis is an important pig pathogen with potential for human transmission. The serotype distributions and phenotypic characteristics vary over time and among regions; however, little is known about the characteristics of S. suis isolates in Korea. In this study, 240 S. suis isolates collected from pigs in Korea in 2009-2010 were serotyped by coagglutination tests, subsequently screened for three virulence-associated genes (mrp, epf and sly) and tested for antimicrobial susceptibility. As for 80 isolates, the serotypes of which were relevant to human infections, clonal complexes (CCs) were further identified by PCR. Serotype 3 was the most prevalent (15.8%), followed by serotype 2 (15.0%), with geographical variation for each serotype. Overall, 55.4% of the isolates carried mrp, whereas only 3.8% carried epf. CC25 was the most prevalent (41.3%) and was related to serotypes 2 and 9. The isolates showed higher susceptibility to ampicillin (93.4%) and ceftiofur (90.8%) than to the other antimicrobial agents tested. The highest resistance rate was observed to tetracycline (98.0%), followed by erythromycin (88.8%). In addition, the resistance to certain antimicrobials was significantly associated, in part, with virulence-associated genes or serotypes. Therefore, continuous characterization of S. suis is essential for the benefit of veterinary and human medicine.

Analysis of group B streptococcal isolates from infants and pregnant women in Portugal revealing two lineages with enhanced invasiveness.

PubMed

Martins, E R; Pessanha, M A; Ramirez, M; Melo-Cristino, J

2007-10-01

The populations of group B streptococcus (GBS) associated with vaginal carriage in pregnant women and invasive neonatal infections in Portugal were compared. GBS isolates were characterized by serotyping, pulsed-field gel electrophoresis (PFGE) profiling, and multilocus sequence typing (MLST). Serotypes III and V accounted for 44% of all colonization isolates (n = 269), whereas serotypes III and Ia amounted to 69% of all invasive isolates (n = 64). Whereas serotype Ia was associated with early-onset disease (EOD), serotype III was associated with late-onset disease (LOD). Characterization by PFGE and MLST identified very diverse populations in carriage and invasive disease. Serotype Ia was represented mainly by a single PFGE cluster defined by sequence type 23 (ST23) and the infrequent ST24. In contrast, serotype III was found in a large number of PFGE clusters and STs, but a single PFGE cluster defined by ST17 was found to be associated with invasive disease. Although serotype III was associated only with LOD, ST17 showed an enhanced capacity to cause both EOD and LOD. Our data reinforce the evidence for enhanced invasiveness of ST17 and identify a lineage expressing serotype Ia capsule and represented by ST23 and ST24 as having enhanced potential to cause EOD.

Comprehensive analysis of Salmonella sequence polymorphisms and development of a LDR-UA assay for the detection and characterization of selected serotypes.

PubMed

Lauri, Andrea; Castiglioni, Bianca; Mariani, Paola

2011-07-01

Salmonella is a major cause of food-borne disease, and Salmonella enterica subspecies I includes the most clinically relevant serotypes. Salmonella serotype determination is important for the disease etiology assessment and contamination source tracking. This task will be facilitated by the disclosure of Salmonella serotype sequence polymorphisms, here annotated in seven genes (sefA, safA, safC, bigA, invA, fimA, and phsB) from 139 S. enterica strains, of which 109 belonging to 44 serotypes of subsp. I. One hundred nineteen polymorphic sites were scored and associated to single serotypes or to serotype groups belonging to S. enterica subsp. I. A diagnostic tool was constructed based on the Ligation Detection Reaction-Universal Array (LDR-UA) for the detection of polymorphic sites uniquely associated to serotypes of primary interest (Salmonella Hadar, Salmonella Infantis, Salmonella Enteritidis, Salmonella Typhimurium, Salmonella Gallinarum, Salmonella Virchow, and Salmonella Paratyphi B). The implementation of promiscuous probes allowed the diagnosis of ten further serotypes that could be associated to a unique hybridization pattern. Finally, the sensitivity and applicability of the tool was tested on target DNA dilutions and with controlled meat contamination, allowing the detection of one Salmonella CFU in 25 g of meat.

Arabidopsis VARIEGATED 3 encodes a chloroplast-targeted, zinc-finger protein required for chloroplast and palisade cell development.

PubMed

Naested, Henrik; Holm, Agnethe; Jenkins, Tom; Nielsen, H Bjørn; Harris, Cassandra A; Beale, Michael H; Andersen, Mathias; Mant, Alexandra; Scheller, Henrik; Camara, Bilal; Mattsson, Ole; Mundy, John

2004-09-15

The stable, recessive Arabidopsis variegated 3 (var3) mutant exhibits a variegated phenotype due to somatic areas lacking or containing developmentally retarded chloroplasts and greatly reduced numbers of palisade cells. The VAR3 gene, isolated by transposon tagging, encodes the 85.9 kDa VAR3 protein containing novel repeats and zinc fingers described as protein interaction domains. VAR3 interacts specifically in yeast and in vitro with NCED4, a putative polyene chain or carotenoid dioxygenase, and both VAR3 and NCED4 accumulate in the chloroplast stroma. Metabolic profiling demonstrates that pigment profiles are qualitatively similar in wild type and var3, although var3 accumulates lower levels of chlorophylls and carotenoids. These results indicate that VAR3 is a part of a protein complex required for normal chloroplast and palisade cell development.

Pyrazinamidase, CR-MOX agar, salicin fermentation-esculin hydrolysis, and D-xylose fermentation for identifying pathogenic serotypes of Yersinia enterocolitica.

PubMed Central

Farmer, J J; Carter, G P; Miller, V L; Falkow, S; Wachsmuth, I K

1992-01-01

We evaluated several simple laboratory tests that have been used to identify pathogenic serotypes of Yersinia enterocolitica or to indicate the pathogenic potential of individual strains. A total of 100 strains of Y. enterocolitica were studied, including 25 isolated during five outbreak investigations, 63 from sporadic cases, and 12 from stock cultures. The pyrazinamidase test, which does not depend on the Yersinia virulence plasmid, correctly identified 60 of 63 (95% sensitivity) strains of pathogenic serotypes and 34 of 37 (92% specificity) strains of nonpathogenic serotypes. Salicin fermentation-esculin hydrolysis (25 degrees C, 48 h) correctly identified all 63 (100% sensitivity) strains of the pathogenic serotypes and 34 of 37 (92% specificity) strains of the nonpathogenic serotypes. The results of the pyrazinamidase and salicin-esculin tests disagreed for only 7 of the 100 strains of Y. enterocolitica, and these would require additional testing. Congo red-magnesium oxalate (CR-MOX) agar determines Congo red dye uptake and calcium-dependent growth at 36 degrees C, and small red colonies are present only if the strain contains the Yersinia virulence plasmid. This test has proven to be extremely useful for freshly isolated cultures, but only 15 of 62 strains of pathogenic serotypes that had been stored for 1 to 10 years were CR-MOX positive. None of the 16 strains of Y. enterocolitica serotype O3 fermented D-xylose, so this test easily differentiated strains of this serotype, which now appears to be the most common in the United States. Although antisera that can actually be used to serotype strains of Y. enterocolitica are not readily available, the four simple tests described above can be used to screen for pathogenic serotypes. Images PMID:1400958

CRISPR Is an Optimal Target for the Design of Specific PCR Assays for Salmonella enterica Serotypes Typhi and Paratyphi A

PubMed Central

Fabre, Laetitia; Le Hello, Simon; Roux, Chrystelle; Issenhuth-Jeanjean, Sylvie; Weill, François-Xavier

2014-01-01

Background Serotype-specific PCR assays targeting Salmonella enterica serotypes Typhi and Paratyphi A, the causal agents of typhoid and paratyphoid fevers, are required to accelerate formal diagnosis and to overcome the lack of typing sera and, in some situations, the need for culture. However, the sensitivity and specificity of such assays must be demonstrated on large collections of strains representative of the targeted serotypes and all other bacterial populations producing similar clinical symptoms. Methodology Using a new family of repeated DNA sequences, CRISPR (clustered regularly interspaced short palindromic repeats), as a serotype-specific target, we developed a conventional multiplex PCR assay for the detection and differentiation of serotypes Typhi and Paratyphi A from cultured isolates. We also developed EvaGreen-based real-time singleplex PCR assays with the same two sets of primers. Principal findings We achieved 100% sensitivity and specificity for each protocol after validation of the assays on 188 serotype Typhi and 74 serotype Paratyphi A strains from diverse genetic groups, geographic origins and time periods and on 70 strains of bacteria frequently encountered in bloodstream infections, including 29 other Salmonella serotypes and 42 strains from 38 other bacterial species. Conclusions The performance and convenience of our serotype-specific PCR assays should facilitate the rapid and accurate identification of these two major serotypes in a large range of clinical and public health laboratories with access to PCR technology. These assays were developed for use with DNA from cultured isolates, but with modifications to the assay, the CRISPR targets could be used in the development of assays for use with clinical and other samples. PMID:24498453

Development and evaluation of tailored specific real-time RT-PCR assays for detection of foot-and-mouth disease virus serotypes circulating in East Africa.

PubMed

Bachanek-Bankowska, Katarzyna; Mero, Herieth R; Wadsworth, Jemma; Mioulet, Valerie; Sallu, Raphael; Belsham, Graham J; Kasanga, Christopher J; Knowles, Nick J; King, Donald P

2016-11-01

Rapid, reliable and accurate diagnostic methods provide essential support to programmes that monitor and control foot-and-mouth disease (FMD). While pan-specific molecular tests for FMD virus (FMDV) detection are well established and widely used in endemic and FMD-free countries, current serotyping methods mainly rely either on antigen detection ELISAs or nucleotide sequencing approaches. This report describes the development of a panel of serotype-specific real-time RT-PCR assays (rRT-PCR) tailored to detect FMDV lineages currently circulating in East Africa. These assays target sequences within the VP1-coding region that share high intra-lineage identity, but do not cross-react with FMD viruses from other serotypes that circulate in the region. These serotype-specific assays operate with the same thermal profile as the pan-diagnostic tests making it possible to run them in parallel to produce C T values comparable to the pan-diagnostic test detecting the 3D-coding region. These assays were evaluated alongside the established pan-specific molecular test using field samples and virus isolates collected from Tanzania, Kenya and Ethiopia that had been previously characterised by nucleotide sequencing. Samples (n=71) representing serotype A (topotype AFRICA, lineage G-I), serotype O (topotypes EA-2 and EA-4), serotype SAT 1 (topotype I (NWZ)) and serotype SAT2 (topotype IV) were correctly identified with these rRT-PCR assays. Furthermore, FMDV RNA from samples that did not contain infectious virus could still be serotyped using these assays. These serotype-specific real-time RT-PCR assays can detect and characterise FMDVs currently circulating in East Africa and hence improve disease control in this region. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Use of biochemical kinetic data to determine strain relatedness among Salmonella enterica subsp. enterica isolates.

PubMed

de la Torre, E; Tello, M; Mateu, E M; Torre, E

2005-11-01

Classical biotyping characterizes strains by creating biotype profiles that consider only positive and negative results for a predefined set of biochemical tests. This method allows Salmonella subspecies to be distinguished but does not allow serotypes and phage types to be distinguished. The objective of this study was to determine the relatedness of isolates belonging to distinct Salmonella enterica subsp. enterica serotypes by using a refined biotyping process that considers the kinetics at which biochemical reactions take place. Using a Vitek GNI+ card for the identification of gram-negative organisms, we determined the biochemical kinetic reactions (28 biochemical tests) of 135 Salmonella enterica subsp. enterica strains of pig origin collected in Spain from 1997 to 2002 (59 Salmonella serotype Typhimurium strains, 25 Salmonella serotype Typhimurium monophasic variant strains, 25 Salmonella serotype Anatum strains, 12 Salmonella serotype Tilburg strains, 7 Salmonella serotype Virchow strains, 6 Salmonella serotype Choleraesuis strains, and 1 Salmonella enterica serotype 4,5,12:-:- strain). The results were expressed as the colorimetric and turbidimetric changes (in percent) and were used to enhance the classical biotype profile by adding kinetic categories. A hierarchical cluster analysis was performed by using the enhanced profiles and resulted in 14 clusters. Six major clusters grouped 94% of all isolates with a similarity of > or =95% within any given cluster, and eight clusters contained a single isolate. The six major clusters grouped not only serotypes of the same type but also phenotypic serotype variations into individual clusters. This suggests that metabolic kinetic reaction data from the biochemical tests commonly used for classic Salmonella enterica subsp. enterica biotyping can possibly be used to determine the relatedness between isolates in an easy and timely manner.

Serotype distribution of Streptococcus pneumoniae in children with invasive diseases in Turkey: 2008-2014.

PubMed

Ceyhan, Mehmet; Ozsurekci, Yasemin; Gürler, Nezahat; Öksüz, Lütfiye; Aydemir, Sohret; Ozkan, Sengul; Yuksekkaya, Serife; Keser Emiroglu, Melike; Gültekin, Meral; Yaman, Akgün; Kiremitci, Abdurrahman; Yanık, Keramettin; Karli, Arzu; Ozcinar, Hatice; Aydin, Faruk; Bayramoglu, Gulcin; Zer, Yasemin; Gulay, Zeynep; Gayyurhan, Efgan Dogan; Gül, Mustafa; Özakın, Cüneyt; Güdücüoğlu, Hüseyin; Perçin, Duygu; Akpolat, Nezahat; Ozturk, Candan; Camcıoğlu, Yıldız; Karadağ Öncel, Eda; Çelik, Melda; Şanal, Laser; Uslu, Hakan

2016-01-01

Successful vaccination policies for protection from invasive pneumococcal diseases (IPD) dependent on determination of the exact serotype distribution in each country. We aimed to identify serotypes of pneumococcal strains causing IPD in children in Turkey and emphasize the change in the serotypes before and after vaccination with 7-valent pneumococcal conjugate vaccine (PCV-7) was included and PCV-13 was newly changed in Turkish National Immunization Program. Streptococcus pneumoniae strains were isolated at 22 different hospitals of Turkey, which provide healthcare services to approximately 65% of the Turkish population. Of the 335 diagnosed cases with S. pneumoniae over the whole period of 2008-2014, the most common vaccine serotypes were 19F (15.8%), 6B (5.9%), 14 (5.9%), and 3 (5.9%). During the first 5 y of age, which is the target population for vaccination, the potential serotype coverage ranged from 57.5 % to 36.8%, from 65.0% to 44.7%, and from 77.4% to 60.5% for PCV-7, PCV-10, and PCV-13 in 2008-2014, respectively. The ratio of non-vaccine serotypes was 27.2% in 2008-2010 whereas was 37.6% in 2011-2014 (p=0.045). S. penumoniae serotypes was less non-susceptible to penicillin as compared to our previous results (33.7 vs 16.5 %, p=0.001). The reduction of those serotype coverage in years may be attributed to increasing vaccinated children in Turkey and the increasing non-vaccine serotype may be explained by serotype replacement. Our ongoing IPD surveillance is a significant source of information for the decision-making processes on pneumococcal vaccination.

Immunogenicity of a 7-valent pneumococcal conjugate vaccine (PCV7) and impact on carriage in Venezuelan children at risk of invasive pneumococcal diseases.

PubMed

Rivera-Olivero, Ismar A; Del Nogal, Berenice; Fuentes, Mariana; Cortez, Rossana; Bogaert, Debby; Hermans, Peter W M; Waard, Jacobus H de

2014-06-30

We evaluated the immunogenicity of the 7-valent pneumococcal conjugate vaccine (PCV7), and its impact on pneumococcal carriage in Venezuelan children at high risk for invasive pneumococcal disease (IPD). 82 children (age 2-59 months) with sickle cell anemia (n=22), chronic heart disease (n=19), HIV infection (n=12), immune-suppressive therapy (n=11) and other IPD-predisposing conditions (n=18) were vaccinated with PCV7 according to CDC-recommended age-related immunization schedules. Blood samples were taken to determine the concentration of IgG antibody, and nasopharyngeal swabs were obtained to isolate Streptococcus pneumoniae, before the first vaccine dose and 1 month after completion of the vaccination schedule. Pneumococcal carriage prior to the first immunization was 27% (n=22), with the most frequently carried serotypes being vaccine serotypes 6B (22%) and 14 (13%). One month after completion of the vaccination scheme pneumococcal carriage was 22% (n=17), dominated by non-vaccine serotypes 19A (24%) and 7F (12%). Before immunization, 65% of the subjects had IgG antibody titers >0.35 μg/mL for five serotypes tested. Post-vaccination, 100% of the subjects showed titers >1.0 μg/mL for all PCV7 serotypes with geometric mean concentrations (GMC) ranging from 1.75 μg/mL (serotype 23F) to 17.16 μg/mL (serotype 14). Children previously colonized with serotype 6B had a significantly lower GMC to this serotype following immunization than children not carrying 6B prior to the first PCV dose (p<0.05). PCV7 is highly immunogenic in Venezuelan children at high-risk for IPD. Vaccination was associated with an immediate shift in nasopharyngeal carriage toward non-PCV7 serotypes. Finally, we observed serotype-specific hyporesponsiveness to immunization after natural carriage with the same serotype in high-risk children. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of a multiplex lateral flow strip test for foot-and-mouth disease virus detection using monoclonal antibodies.

PubMed

Yang, Ming; Caterer, Nigel R; Xu, Wanhong; Goolia, Melissa

2015-09-01

Foot-and-mouth disease (FMD) is one of the world's most highly contagious animal diseases with tremendous economic consequences. A rapid and specific test for FMD diagnosis at the site of a suspected outbreak is crucial for the implementation of control measures. This project developed a multiplex lateral flow immunochromatographic strip test (multiplex-LFI) for the rapid detection and serotyping of FMD viruses. The monoclonal antibodies (mAbs) against serotypes O, A, and Asia 1 were used as capture mAbs. The mAbs were conjugated with fluorescein, rhodamine or biotin for serotype O, A and Asia 1, respectively. The detection mAbs which consisted of a serotype-independent mAb in combination with one serotype A-specific mAb and one Asia 1-specific mAb, were each colloidal gold-conjugated. The strips used in this study contained one control line and three test lines, which corresponded to one of the three serotypes, O, A or Asia 1. The newly developed multiplex-LFI strip test specifically identified serotype O (n=46), A (n=45) and Asia 1 (n=17) in all tested field isolates. The sensitivity of this strip test was comparable to the double antibody sandwich ELISA for serotypes O and A, but lower than the ELISA for serotype Asia 1. The multiplex-LFI strip test identified all tissue suspensions from animals that were experimentally inoculated with serotypes O, A or Asia 1. FMD viruses were detected in 38% and 50% of the swab samples from the lesion areas of experimentally inoculated sheep for serotypes O and A, respectively. The capability of the multiplex-LFI strip tests to produce rapid results with high specificity for FMD viruses of multiple serotypes makes this test a valuable tool to detect FMD viruses at outbreak sites. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Genetic Characterization of Serotypes A and Asia-1 Foot-and-mouth Disease Viruses in Balochistan, Pakistan, in 2011.

PubMed

Ullah, A; Jamal, S M; Romey, A; Gorna, K; Kakar, M A; Abbas, F; Ahmad, J; Zientara, S; Bakkali Kassimi, L

2017-10-01

This study reports characterization of foot-and-mouth disease virus (FMDV) in samples collected from Balochistan, Pakistan. FMDV was detected by pan-FMDV real-time RT-PCR in 31 samples (epithelial and oral swabs) collected in 2011 from clinical suspect cases. Of these, 29 samples were serotyped by serotype-specific real-time RT-PCR assays and were confirmed by sequencing the VP1 coding region. Sixteen samples were found positive for serotype A and eight for serotype Asia-1, whereas five samples were found positive for both serotypes A and Asia-1. Two serotype A positive samples were found positive for two different strains of serotype A FMDV each. Phylogenetic analyses of serotype A FMDVs showed circulation of at least three different sublineages within the A-Iran05 lineage. These included two earlier reported sublineages, A-Iran05 HER -10 and A-Iran05 FAR -11 , and a new sublineage, designated here as A-Iran05 BAL -11 . This shows that viruses belonging to the A-Iran05 lineage are continuously evolving in the region. Viruses belonging to the A-Iran05 FAR -11 sublineage showed close identity with the viruses circulating in 2009 in Pakistan and Afghanistan. However, viruses belonging to the A-Iran05 HER -10 detected in Balochistan, Pakistan, showed close identity with the viruses circulating in Kyrgyzstan, Iran and Kazakhstan in 2011 and 2012, showing that viruses responsible for outbreak in these countries have a common origin. Serotype Asia-1 FMDVs reported in this study all belonged to the earlier reported Group-VII (Sindh-08), which is currently a dominant strain in the West Eurasian region. Detection of two different serotypes of FMDV or/and two different strains of the same serotype in one animal/sample shows complexity in occurrence of FMD in the region. © 2016 Blackwell Verlag GmbH.

Resistance to Southern Root-knot Nematode (Meloidogyne incognita) in Wild Watermelon (Citrullus lanatus var. citroides)

PubMed Central

Thies, Judy A.; Ariss, Jennifer J.; Kousik, Chandrasekar S.; Hassell, Richard L.; Levi, Amnon

2016-01-01

Southern root-knot nematode (RKN, Meloidogyne incognita) is a serious pest of cultivated watermelon (Citrullus lanatus var. lanatus) in southern regions of the United States and no resistance is known to exist in commercial watermelon cultivars. Wild watermelon relatives (Citrullus lanatus var. citroides) have been shown in greenhouse studies to possess varying degrees of resistance to RKN species. Experiments were conducted over 2 yr to assess resistance of southern RKN in C. lanatus var. citroides accessions from the U.S. Watermelon Plant Introduction Collection in an artificially infested field site at the U.S. Vegetable Laboratory in Charleston, SC. In the first study (2006), 19 accessions of C. lanatus var. citroides were compared with reference entries of Citrullus colocynthis and C. lanatus var. lanatus. Of the wild watermelon accessions, two entries exhibited significantly less galling than all other entries. Five of the best performing C. lanatus var. citroides accessions were evaluated with and without nematicide at the same field site in 2007. Citrullus lanatus var. citroides accessions performed better than C. lanatus var. lanatus and C. colocynthis. Overall, most entries of C. lanatus var. citroides performed similarly with and without nematicide treatment in regard to root galling, visible egg masses, vine vigor, and root mass. In both years of field evaluations, most C. lanatus var. citroides accessions showed lesser degrees of nematode reproduction and higher vigor and root mass than C. colocynthis and C. lanatus var. lanatus. The results of these two field evaluations suggest that wild watermelon populations may be useful sources of resistance to southern RKN. PMID:27168648

Resistance to Southern Root-knot Nematode (Meloidogyne incognita) in Wild Watermelon (Citrullus lanatus var. citroides).

PubMed

Thies, Judy A; Ariss, Jennifer J; Kousik, Chandrasekar S; Hassell, Richard L; Levi, Amnon

2016-03-01

Southern root-knot nematode (RKN, Meloidogyne incognita) is a serious pest of cultivated watermelon (Citrullus lanatus var. lanatus) in southern regions of the United States and no resistance is known to exist in commercial watermelon cultivars. Wild watermelon relatives (Citrullus lanatus var. citroides) have been shown in greenhouse studies to possess varying degrees of resistance to RKN species. Experiments were conducted over 2 yr to assess resistance of southern RKN in C. lanatus var. citroides accessions from the U.S. Watermelon Plant Introduction Collection in an artificially infested field site at the U.S. Vegetable Laboratory in Charleston, SC. In the first study (2006), 19 accessions of C. lanatus var. citroides were compared with reference entries of Citrullus colocynthis and C. lanatus var. lanatus. Of the wild watermelon accessions, two entries exhibited significantly less galling than all other entries. Five of the best performing C. lanatus var. citroides accessions were evaluated with and without nematicide at the same field site in 2007. Citrullus lanatus var. citroides accessions performed better than C. lanatus var. lanatus and C. colocynthis. Overall, most entries of C. lanatus var. citroides performed similarly with and without nematicide treatment in regard to root galling, visible egg masses, vine vigor, and root mass. In both years of field evaluations, most C. lanatus var. citroides accessions showed lesser degrees of nematode reproduction and higher vigor and root mass than C. colocynthis and C. lanatus var. lanatus. The results of these two field evaluations suggest that wild watermelon populations may be useful sources of resistance to southern RKN.

Using ClinVar as a Resource to Support Variant Interpretations

PubMed Central

Harrison, Steven M.; Riggs, Erin R.; Maglott, Donna R.; Lee, Jennifer M.; Azzariti, Danielle R.; Niehaus, Annie; Ramos, Erin M.; Martin, Christa L.; Landrum, Melissa J.; Rehm, Heidi L.

2016-01-01

ClinVar is a freely accessible, public archive of reports of the relationships among genomic variants and phenotypes. To facilitate evaluation of the clinical significance of each variant, ClinVar aggregates submissions of the same variant, displays supporting data from each submission, and determines if the submitted clinical interpretations are conflicting or concordant. The unit describes how to (1) identify sequence and structural variants of interest in ClinVar with by multiple searching approaches, including Variation Viewer and (2) understand the display of submissions to ClinVar and the evidence supporting each interpretation. By following this protocol, ClinVar users will be able to learn how to incorporate the wealth of resources and knowledge in ClinVar into variant curation and interpretation. PMID:27037489

Comparison of Toxicological Properties of Botulinum Neurotoxin Serotypes A and B in Mice

USDA-ARS?s Scientific Manuscript database

Botulinum neurotoxins (BoNTs) are among the most toxic biological toxins for humans. Of the seven known serotypes (A-G) of BoNT, serotypes A, B and E cause most of the human foodborne intoxications. In this study, we compared the toxicological properties of BoNT serotype A and B holotoxins and compl...

Rescue and serotypic characterization of noncultivable human rotavirus by gene reassortment.

PubMed Central

Greenberg, H B; Wyatt, R G; Kapikian, A Z; Kalica, A R; Flores, J; Jones, R

1982-01-01

Thirty-three of 50 noncultivable human rotavirus strains from a variety of locations were successfully rescued by gene reassortment. The serotype of each of the 33 strains was investigated by a qualitative cytopathic effect neutralization assay. Nineteen strains resembled the previously characterized human rotavirus serotype Wa, whereas three strains were serologically related to the DS-1 strain. Eleven strains appeared to be serotypically distinct from the Wa and DS-1 strains and thus apparently represent one or more new human rotavirus serotypes. Images PMID:6286486

Comparison of dkgB-linked intergenic sequence ribotyping to DNA microarray hybridization for assigning serotype to Salmonella enterica

PubMed Central

Guard, Jean; Sanchez-Ingunza, Roxana; Morales, Cesar; Stewart, Tod; Liljebjelke, Karen; Kessel, JoAnn; Ingram, Kim; Jones, Deana; Jackson, Charlene; Fedorka-Cray, Paula; Frye, Jonathan; Gast, Richard; Hinton, Arthur

2012-01-01

Two DNA-based methods were compared for the ability to assign serotype to 139 isolates of Salmonella enterica ssp. I. Intergenic sequence ribotyping (ISR) evaluated single nucleotide polymorphisms occurring in a 5S ribosomal gene region and flanking sequences bordering the gene dkgB. A DNA microarray hybridization method that assessed the presence and the absence of sets of genes was the second method. Serotype was assigned for 128 (92.1%) of submissions by the two DNA methods. ISR detected mixtures of serotypes within single colonies and it cost substantially less than Kauffmann–White serotyping and DNA microarray hybridization. Decreasing the cost of serotyping S. enterica while maintaining reliability may encourage routine testing and research. PMID:22998607

Simultaneous Rapid Detection and Serotyping of Cronobacter sakazakii Serotypes O1, O2, and O3 by Using Specific Monoclonal Antibodies

PubMed Central

Scharinger, Eva J.; Dietrich, Richard; Kleinsteuber, Ina; Märtlbauer, Erwin

2016-01-01

Cronobacter sakazakii is a foodborne pathogen associated with rare but often lethal infections in neonates. Powdered infant formula (PIF) represents the most frequent source of infection. Out of the identified serotypes (O1 to O7), O1, O2, and O3 are often isolated from clinical and PIF samples. Serotype-specific monoclonal antibodies (MAbs) suitable for application in enzyme immunoassays (EIAs) for the rapid detection of C. sakazakii have not yet been developed. In this study, we created specific MAbs with the ability to bind to C. sakazakii of serotypes O1, O2, and O3. Characterization by indirect EIAs, immunofluorescence, motility assays, and immunoblotting identified lipopolysaccharide (LPS) and exopolysaccharide (EPS) as the antigenic determinants of the MAbs. The established sandwich EIAs were highly sensitive and were able to detect between 2 × 103 and 9 × 106 CFU/ml. Inclusivity tests confirmed that 93% of serotype O1 strains, 100% of O2 strains, and 87% of O3 strains were detected at low cell counts. No cross-reactivity with >100 strains of Cronobacter spp. and other Enterobacteriaceae was observed, except for that with C. sakazakii serotype O3 and Cronobacter muytjensii serotype O1. Moreover, the sandwich EIAs detected C. sakazakii in PIF samples artificially contaminated with 1 to 10 bacterial cells per 10 g of sample after 15 h of preenrichment. The use of these serotype-specific MAbs not only allows the reliable detection of C. sakazakii strains but also enables simultaneous serotyping in a simple sandwich EIA method. PMID:26850303

Roles of oral bacteria in cardiovascular diseases--from molecular mechanisms to clinical cases: Cell-surface structures of novel serotype k Streptococcus mutans strains and their correlation to virulence.

PubMed

Nakano, Kazuhiko; Nomura, Ryota; Matsumoto, Michiyo; Ooshima, Takashi

2010-01-01

Streptococcus mutans is generally known as a pathogen of dental caries, and it is also considered to cause bacteremia and infective endocarditis (IE). S. mutans was previously classified into 3 serotypes, c, e, and f, due to the different chemical compositions of the serotype-specific polysaccharides, which are composed of a rhamnose backbone and glucose side chains. We recently designated non-c/e/f serotype S. mutans strains as novel serotype k, which is characterized by a drastic reduction in the amount of the glucose side chain. A common biological feature of novel serotype-k strains is a lower level of cariogenicity due to alterations of several major cell surface protein antigens. As for virulence in blood, these strains survive in blood for a longer duration due to lower antigenicity, while the detection rate of all strains carrying the gene encoding collagen-binding adhesin has been shown to be high. Furthermore, molecular biological analyses of infected heart valve specimens obtained from IE patients revealed a high detection rate of serotype-k S. mutans. Together, these findings suggest that serotype-k S. mutans strains show low cariogenicity but high virulence in blood as compared to the other serotypes, due to alterations of several cell surface structures.

Capsular serotypes, virulence-associated genes and antimicrobial susceptibility of Streptococcus suis isolates from pigs in Korea

PubMed Central

OH, Sang-Ik; JEON, Albert Byungyun; JUNG, Byeong-Yeal; BYUN, Jae-Won; GOTTSCHALK, Marcelo; KIM, Aeran; KIM, Jong Wan; KIM, Ha-Young

2017-01-01

Streptococcus suis is an important pig pathogen with potential for human transmission. The serotype distributions and phenotypic characteristics vary over time and among regions; however, little is known about the characteristics of S. suis isolates in Korea. In this study, 240 S. suis isolates collected from pigs in Korea in 2009–2010 were serotyped by coagglutination tests, subsequently screened for three virulence-associated genes (mrp, epf and sly) and tested for antimicrobial susceptibility. As for 80 isolates, the serotypes of which were relevant to human infections, clonal complexes (CCs) were further identified by PCR. Serotype 3 was the most prevalent (15.8%), followed by serotype 2 (15.0%), with geographical variation for each serotype. Overall, 55.4% of the isolates carried mrp, whereas only 3.8% carried epf. CC25 was the most prevalent (41.3%) and was related to serotypes 2 and 9. The isolates showed higher susceptibility to ampicillin (93.4%) and ceftiofur (90.8%) than to the other antimicrobial agents tested. The highest resistance rate was observed to tetracycline (98.0%), followed by erythromycin (88.8%). In addition, the resistance to certain antimicrobials was significantly associated, in part, with virulence-associated genes or serotypes. Therefore, continuous characterization of S. suis is essential for the benefit of veterinary and human medicine. PMID:28250312

Disinfectant susceptibility of different Salmonella serotypes isolated from chicken and egg production chains.

PubMed

Long, M; Lai, H; Deng, W; Zhou, K; Li, B; Liu, S; Fan, L; Wang, H; Zou, L

2016-09-01

The study aimed to serotype the Salmonella isolates recovered from chicken and egg production chains, and to investigate the disinfectant resistance phenotypes and genotypes of these isolates. The Salmonella isolates were serotyped, and the minimal inhibitory concentrations (MICs) of disinfectants were determined. Results showed that the Salmonella isolates recovered from both chains were diverse, and the serotypes in each part of the production chain and between the two production chains were significantly different. In the chicken production chain, 19 different serotypes were recovered, while only five serotypes were found in the egg production chain. The isolates showed a high susceptibility to didecyldimethylammonium bromide (DDAB) but a low susceptibility to benzalkonium chloride (BC), benzalkonium bromide (BAB) and chlorhexidine (CHX). Salmonella Enteritidis and Salmonella Typhimurium were more resistant to BC and BAB. The qacEΔ1 and qacF resistance genes were detected in 26·7 and 7·7% of the isolates respectively. The qacEΔ1 gene was frequently found in Salmonella Derby and Salm. Enteritidis (P < 0·05). Our findings indicated that Salmonella was commonly present in both chains, and could serve as a critical vector in spreading disinfectant resistance associated with different serotypes. This study first demonstrated disinfectant resistance phenotypes and genotypes of serotyped Salmonella. The study highlights the need for monitoring the disinfectant resistance varied in different Salmonella serotypes. © 2016 The Society for Applied Microbiology.

Serotype-Specific Protection Against Treponema hyodysenteriae Infection in Ligated Colonic Loops of Pigs Recovered from Swine Dysentery

PubMed Central

Joens, L. A.; Whipp, S. C.; Glock, R. D.; Neussen, Mary E.

1983-01-01

Resistance to Treponema hyodysenteriae (serotypes 1, 2, 3, and 4) infection was evaluated in ligated colonic loops in pigs recovered from swine dysentery. Lesions were present in most loops from recovered swine inoculated with heterologous serotypes; however, lesions were not present in loops of recovered swine inoculated with homologous serotypes. PMID:6822429

Other age groups than children need to be considered as carriers of Streptococcal pneumoniae serotypes.

PubMed

Slotved, Hans-Christian

2016-10-02

We need to raise the issue that focus on children as the only carriage group for pneumococci is not optimal; we need to consider that other age groups might also be carriers of pneumococcal serotypes causing invasive pneumococcal diseases (IPD) in unvaccinated age groups. The pneumococcal conjugate vaccines (PCV) have successfully removed IPD from vaccinated children. Studies have shown an effect of PCV reducing the pneumococcal carriage of PCV serotypes in children. The status for several countries having used PCV for many years is that they do not see PCV serotypes neither carried nor as a cause of IPD in children. PCV vaccination of children has shown a herd protection effect in unvaccinated groups as a reduction in IPD cases caused by PCV serotypes. However, not all PCV serotypes have disappeared as the cause of IPD in the unvaccinated age groups. The author therefore believes that if we are to see PCV serotypes disappear as a cause of IPD in unvaccinated age groups, we need to perform further carriage studies to examine carriage in other age groups. Alternatively, all age groups should be vaccinated against pneumococci to eliminate IPD caused by PCV serotypes from possible hidden carriers.

Capsular Serotype and Antibiotic Resistance of Streptococcus pneumoniae Isolates in Two Chilean Cities

PubMed Central

Inostroza, Jaime; Trucco, Olivia; Prado, Valeria; Vinet, Ana Maria; Retamal, Gloria; Ossa, Gonzalo; Facklam, Richard R.; Sorensen, Ricardo U.

1998-01-01

We compared the incidence of nasopharyngeal colonization by Streptococcus pneumoniae, the serotypes causing mucosal and invasive diseases, and the antibiotic resistance of these strains in patients admitted to three large hospitals and children attending day care centers in two Chilean cities (Santiago and Temuco). The populations in both cities were similar in ethnic background, socioeconomic status, family size, and access to medical care. Significant differences in nasopharyngeal colonization rates, in serotypes causing infections, and in antibiotic resistance were found between the two cities. In children 0 to 2 years of age, 42% were colonized with S. pneumoniae in Santiago compared to 14% in Temuco. A total of 41 serotypes were identified in both Chilean cities studied. Six serotypes were found only in Santiago; 14 serotypes were found only in Temuco. Antibiotic-resistant serotypes 6A, 6B, 14, 19F, and 23F were detected only in Santiago. We show that important differences in the incidence of nasopharyngeal carriage, infection, and S. pneumoniae serotypes can exist in similar populations in different areas of the same country. Our findings are relevant for prevention strategies, antibiotic usage, and vaccine design. PMID:9521139

Granulocyte phagocytosis and killing virulent and avirulent serotypes of Streptococcus pneumoniae.

PubMed

Braconier, J H; Odeberg, H

1982-08-01

Five commonly isolated Streptococcus pneumoniae serotypes (3, 6, 14, 19, and 23) and five rarely found serotypes (31, 35, 36, 42, and 43) were compared to elucidate whether increased resistance against granulocyte phagocytosis and killing could explain the restricted number of pneumococcal serotypes found in infections. There was a great variation in sensitivity among the serotypes to granulocyte killing. No consistent pattern was found when pathogenicity and resistance to granulocytes were compared. The results do not indicate that the increased tendency of pathogenic pneumococcal serotypes to cause infections is due to increased resistance to granulocytes. Monocyte killing of some pneumococal serotypes (6, 19, 23, 35, and 43) was also studied and found very similar to granulocyte killing. Defective granulocyte kiling of encapsulated pneumococci was due to impaired phagocytosis. Moreover, no correlation was found between the sensitivity of the serotypes to isolated intragranulocytic microbial systems (i.e., MPO, hydrogen peroxide, or CCP) and the sensitivity to killing by intact granulocytes or pathogenicity. The significance of both the classical and alternative complement pathways for pneumococcal opsonization was indicated by reduced, the residual phagocytosis in C2-deficient and MgEGTA-chelated serum.

Molecular characterization of Orientia tsutsugamushi serotypes causing scrub typhus outbreak in southern region of Andhra Pradesh, India.

PubMed

Usha, K; Kumar, E; Kalawat, Usha; Kumar, B Siddhartha; Chaudhury, A; Gopal, D V R Sai

2016-10-01

Scrub typhus is a vector-borne zoonotic infection caused by Orientiatsutsugamushi. Local epidemiology of the circulating serotypes of scrub typhus is not available from most parts of India. We conducted this study for the diagnosis of scrub typhus using IgM ELISA and to detect O. tsutsugamushi serotypes circulating in southern Andhra Pradesh, India. Samples were collected from patients clinically suspected to have scrub typhus and were subjected to IgM ELISA to measure IgM antibodies against O. tsutsugamushi. Nested polymerase chain reaction (PCR) was performed targeting strain-specific regions in ELISA-positive samples. Of a total of 663 samples, 258 (38.91%) were found to be positive by IgM ELISA. Serotypes could be detected in 230 (34.69%) samples only. Only two serotypes, Karp and Kawasaki, were found in the serum samples, with the former being predominant. The dual infection of Karp and Kawasaki serotypes was found in seven patients. Other serotypes such as Gilliam, Kuroki and Kato were not detected in the samples. The nested PCR products proved useful in presumptively identifying the endemic O. tsutsugamushi serotypes. The present study could be significant in understanding scrub typhus epidemiology in this region.

Pneumococcal Capsules and Their Types: Past, Present, and Future

PubMed Central

Geno, K. Aaron; Gilbert, Gwendolyn L.; Song, Joon Young; Skovsted, Ian C.; Klugman, Keith P.; Jones, Christopher; Konradsen, Helle B.

2015-01-01

SUMMARY Streptococcus pneumoniae (the pneumococcus) is an important human pathogen. Its virulence is largely due to its polysaccharide capsule, which shields it from the host immune system, and because of this, the capsule has been extensively studied. Studies of the capsule led to the identification of DNA as the genetic material, identification of many different capsular serotypes, and identification of the serotype-specific nature of protection by adaptive immunity. Recent studies have led to the determination of capsular polysaccharide structures for many serotypes using advanced analytical technologies, complete elucidation of genetic basis for the capsular types, and the development of highly effective pneumococcal conjugate vaccines. Conjugate vaccine use has altered the serotype distribution by either serotype replacement or switching, and this has increased the need to serotype pneumococci. Due to great advances in molecular technologies and our understanding of the pneumococcal genome, molecular approaches have become powerful tools to predict pneumococcal serotypes. In addition, more-precise and -efficient serotyping methods that directly detect polysaccharide structures are emerging. These improvements in our capabilities will greatly enhance future investigations of pneumococcal epidemiology and diseases and the biology of colonization and innate immunity to pneumococcal capsules. PMID:26085553

Bivalent vaccination against pneumonic pasteurellosis in domestic sheep and goats with modified-live in-frame lktA deletion mutants of Mannheimia haemolytica.

PubMed

Briggs, Robert E; Hauglund, Melissa J; Maheswaran, Samuel K; Tatum, Fred M

2013-11-01

A temperature-sensitive shuttle vector, pBB80C, was utilized to generate in-frame deletion mutants of the leukotoxin structural gene (lktA) of Mannheimia haemolytica serotypes 1, 2, 5, 6, 7, 8, 9, and 12. Culture supernatants from the mutants contained a truncated protein with an approximate molecular weight of 66 kDa which was reactive to anti-leukotoxin monoclonal antibody. No protein reactive to anti-LktA monoclonal antibody was detected at the molecular weight 100-105 kDa of native LktA. Sheep and goats vaccinated intramuscularly with a mixture of serotypes 5 and 6 mutants were resistant to virulent challenge with a mixture of the wild-type parent strains. These vaccinates responded serologically to both vaccine serotypes and exhibited markedly-reduced lung lesion volume and pulmonary infectious load compared to control animals. Control animals yielded a mixture of serotypes from lung lobes, but the proportion even within an individual animal varied widely from 95% serotype 5-95% serotype 6. Cultures recovered from liver were homogeneous, but two animals yielded serotype 5 and the other two yielded serotype 6 in pure culture. Published by Elsevier Ltd.

Pneumococcal Capsules and Their Types: Past, Present, and Future.

PubMed

Geno, K Aaron; Gilbert, Gwendolyn L; Song, Joon Young; Skovsted, Ian C; Klugman, Keith P; Jones, Christopher; Konradsen, Helle B; Nahm, Moon H

2015-07-01

Streptococcus pneumoniae (the pneumococcus) is an important human pathogen. Its virulence is largely due to its polysaccharide capsule, which shields it from the host immune system, and because of this, the capsule has been extensively studied. Studies of the capsule led to the identification of DNA as the genetic material, identification of many different capsular serotypes, and identification of the serotype-specific nature of protection by adaptive immunity. Recent studies have led to the determination of capsular polysaccharide structures for many serotypes using advanced analytical technologies, complete elucidation of genetic basis for the capsular types, and the development of highly effective pneumococcal conjugate vaccines. Conjugate vaccine use has altered the serotype distribution by either serotype replacement or switching, and this has increased the need to serotype pneumococci. Due to great advances in molecular technologies and our understanding of the pneumococcal genome, molecular approaches have become powerful tools to predict pneumococcal serotypes. In addition, more-precise and -efficient serotyping methods that directly detect polysaccharide structures are emerging. These improvements in our capabilities will greatly enhance future investigations of pneumococcal epidemiology and diseases and the biology of colonization and innate immunity to pneumococcal capsules. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Serotyping of Actinobacillus pleuropneumoniae serotype 5 strains using a monoclonal-based polystyrene agglutination test.

PubMed Central

Dubreuil, J D; Letellier, A; Stenbaek, E; Gottschalk, M

1996-01-01

A polystyrene agglutination test has been developed for serotyping Actinobacillus pleuropneumoniae serotype 5a and 5b strains. Protein A-coated polystyrene microparticles were sensitized with a murine monoclonal antibody recognizing an epitope on serotype 5 LPS-O chain as shown by SDS-PAGE and Western blotting. A total of 205 A. pleuropneumoniae, strains including all 12 serotype reference strains and 13 strains representing 8 common bacterial species associated with swine or related to A. pleuropneumoniae, were tested by mixing 25 microL of polystyrene reagent with the same volume of a dense suspension of bacterial cells grown for 18 h. All A. pleuropneumoniae strains had been previously serotyped using standard procedures. The polystyrene agglutination test was rapid (less than 3 min) and easy to perform. Overall a very good correlation (97.3%) with the standard techniques was found. The sensitized polystyrene particles were stable for at least 6 mo. Images Figure 1. PMID:8825998

Pediatric Complicated Pneumonia Caused by Streptococcus pneumoniae Serotype 3 in 13-Valent Pneumococcal Conjugate Vaccinees, Portugal, 2010-2015.

PubMed

Silva-Costa, Catarina; Brito, Maria João; Pinho, Marcos D; Friães, Ana; Aguiar, Sandra I; Ramirez, M; Melo-Cristino, Jose

2018-07-01

Despite use of 7-valent pneumococcal conjugate vaccine, incidence of pleural effusion and empyema (pediatric complicated pneumococcal pneumonia [PCPP]) is reportedly increasing globally. We cultured and performed PCR on 152 pleural fluid samples recovered from pediatric patients in Portugal during 2010-2015 to identify and serotype Streptococcus pneumoniae. We identified only 17 cases by culture, but molecular methods identified S. pneumoniae in 68% (92/135) of culture-negative samples. The most frequent serotypes were 3, 1, and 19A, together accounting for 62% (68/109) of cases. Nineteen cases attributable to 13-valent pneumococcal conjugate vaccine (PCV13) serotypes (mostly serotype 3) were detected among 22 children age-appropriately vaccinated with PCV13. The dominance of the additional serotypes included in PCV13 among PCPP cases in Portugal continues, even with PCV13 available on the private market (without reimbursement) since 2010 and with average annual coverage of 61% among age-eligible children. Our data suggest reduced effectiveness of PCV13 against serotype 3 PCPP.

Prevalence of GBS serotype III and identification of a ST 17-like genotype from neonates with invasive diseases in Guangzhou, China.

PubMed

Liu, Junyan; Xu, Ruiru; Zhong, Huamin; Zhong, Yukui; Xie, Yongqiang; Li, Lin; Li, Bing; Chen, Dingqiang; Xu, Zhenbo

2018-05-03

The aim of this study is to understand the surveillance of Streptococcus agalactiae (GBS) serotype and genotype which help developing specific vaccine for GBS infection. The GBS serotype was determined by strep-B-Latex rapid agglutination method and multiplex PCR assay based on the differences among serotypes. Alleles and multilocus sequence types (MLST) were determined using the GBS MLST Web site. Four GBS serotypes (Ia, Ib, III, and V) were identified, with serotype III which was intimately associated with purulent meningitis and sepsis, as the dominance. In EOD cases, sepsis and pneumonia showed dominance, but purulent meningitis was dominant in LOD cases. Also, a new ST-17 like type which might be a clone derive from ST-17 and emerge among neonatal disease cases was identified. The prevalence of GBS serotype and genotype and their relation with GBS diseases guide the development of capsular polysaccharide vaccine. Copyright © 2018. Published by Elsevier Ltd.

iVAR: a program for imputing missing data in multivariate time series using vector autoregressive models.

PubMed

Liu, Siwei; Molenaar, Peter C M

2014-12-01

This article introduces iVAR, an R program for imputing missing data in multivariate time series on the basis of vector autoregressive (VAR) models. We conducted a simulation study to compare iVAR with three methods for handling missing data: listwise deletion, imputation with sample means and variances, and multiple imputation ignoring time dependency. The results showed that iVAR produces better estimates for the cross-lagged coefficients than do the other three methods. We demonstrate the use of iVAR with an empirical example of time series electrodermal activity data and discuss the advantages and limitations of the program.

Positive Selection of Plasmodium falciparum Parasites With Multiple var2csa-Type PfEMP1 Genes During the Course of Infection in Pregnant Women

PubMed Central

Salanti, Ali; Lavstsen, Thomas; Nielsen, Morten A.; Theander, Thor G.; Leke, Rose G. F.; Lo, Yeung Y.; Bobbili, Naveen; Arnot, David E.; Taylor, Diane W.

2011-01-01

Placental malaria infections are caused by Plasmodium falciparum–infected red blood cells sequestering in the placenta by binding to chondroitin sulfate A, mediated by VAR2CSA, a variant of the PfEMP1 family of adhesion antigens. Recent studies have shown that many P. falciparum genomes have multiple genes coding for different VAR2CSA proteins, and parasites with >1 var2csa gene appear to be more common in pregnant women with placental malaria than in nonpregnant individuals. We present evidence that, in pregnant women, parasites containing multiple var2csa-type genes possess a selective advantage over parasites with a single var2csa gene. Accumulation of parasites with multiple copies of the var2csa gene during the course of pregnancy was also correlated with the development of antibodies involved in blocking VAR2CSA adhesion. The data suggest that multiplicity of var2csa-type genes enables P. falciparum parasites to persist for a longer period of time during placental infections, probably because of their greater capacity for antigenic variation and evasion of variant-specific immune responses. PMID:21592998

Antimicrobial susceptibility and serotypes of Actinobacillus (Haemophilus) pleuropneumoniae recovered from Missouri swine.

PubMed

Fales, W H; Morehouse, L G; Mittal, K R; Bean-Knudsen, C; Nelson, S L; Kintner, L D; Turk, J R; Turk, M A; Brown, T P; Shaw, D P

1989-01-01

The antimicrobial susceptibility of 73 Actinobacillus (Haemophilus) pleuropneumoniae isolates from swine in Missouri was determined with a microdilution minimal inhibitory concentration test system. Serotyping was accomplished by means of co-agglutination. Serotype 1 (39/73) and serotype 5 (30/73) were commonly found, whereas serotype 7 (4/73) was infrequently encountered. Most isolates (MIC90) were found susceptible to ampicillin (amoxicillin), cephalothin, penicillin, erythromycin, gentamicin, and kanamycin. Marked resistance was found with oxytetracycline, tylosin, and sulfadimethoxine. The data indicate that use of ampicillin (amoxicillin) or penicillin may correlate well with the favorable outcome of treatment.

Multilocus variable-number tandem repeat analysis for molecular typing and phylogenetic analysis of Shigella flexneri

PubMed Central

2009-01-01

Background Shigella flexneri is one of the causative agents of shigellosis, a major cause of childhood mortality in developing countries. Multilocus variable-number tandem repeat (VNTR) analysis (MLVA) is a prominent subtyping method to resolve closely related bacterial isolates for investigation of disease outbreaks and provide information for establishing phylogenetic patterns among isolates. The present study aimed to develop an MLVA method for S. flexneri and the VNTR loci identified were tested on 242 S. flexneri isolates to evaluate their variability in various serotypes. The isolates were also analyzed by pulsed-field gel electrophoresis (PFGE) to compare the discriminatory power and to evaluate the usefulness of MLVA as a tool for phylogenetic analysis of S. flexneri. Results Thirty-six VNTR loci were identified by exploring the repeat sequence loci in genomic sequences of Shigella species and by testing the loci on nine isolates of different subserotypes. The VNTR loci in different serotype groups differed greatly in their variability. The discriminatory power of an MLVA assay based on four most variable VNTR loci was higher, though not significantly, than PFGE for the total isolates, a panel of 2a isolates, which were relatively diverse, and a panel of 4a/Y isolates, which were closely-related. Phylogenetic groupings based on PFGE patterns and MLVA profiles were considerably concordant. The genetic relationships among the isolates were correlated with serotypes. The phylogenetic trees constructed using PFGE patterns and MLVA profiles presented two distinct clusters for the isolates of serotype 3 and one distinct cluster for each of the serotype groups, 1a/1b/NT, 2a/2b/X/NT, 4a/Y, and 6. Isolates that had different serotypes but had closer genetic relatedness than those with the same serotype were observed between serotype Y and subserotype 4a, serotype X and subserotype 2b, subserotype 1a and 1b, and subserotype 3a and 3b. Conclusions The 36 VNTR loci identified exhibited considerably different degrees of variability among S. flexneri serotype groups. VNTR locus could be highly variable in a serotype but invariable in others. MLVA assay based on four highly variable loci could display a comparable resolving power to PFGE in discriminating isolates. MLVA is also a prominent molecular tool for phylogenetic analysis of S. flexneri; the resulting data are beneficial to establish clear clonal patterns among different serotype groups and to discern clonal groups among isolates within the same serotype. As highly variable VNTR loci could be serotype-specific, a common MLVA protocol that consists of only a small set of loci, for example four to eight loci, and that provides high resolving power to all S. flexneri serotypes may not be obtainable. PMID:20042119

AFLP Phylogeny of 36 Erythroxylum species- genetic relationships among Erythroxylum species inferred by AFLP analysis

USDA-ARS?s Scientific Manuscript database

The plant genus Erythroxylum is known for four cultivated taxa, Erythroxylum coca var. coca (Ecc), Erythroxylum coca var. ipadu (Eci), Erythroxylum novogranatense var. novogranatense (Enn) and Erythroxylum novogranatense var. truxillense (Ent) that are cultivated primarily for the illicit extraction...

Trends of invasive pneumococcal disease and its serotypes in the Autonomous Community of Madrid.

PubMed

Latasa Zamalloa, Pello; Sanz Moreno, Juan Carlos; Ordobás Gavín, María; Barranco Ordoñez, María Dolores; Insúa Marisquerena, Esther; Gil de Miguel, Ángel; Fernández Chávez, Abelardo Claudio; García-Comas, Luis

2017-12-05

Streptococcus pneumoniae is an important cause of morbidity. Vaccination is the most effective measure to prevent it. The aim of this study is to analyse the evolution of invasive pneumococcal disease (IPD). Observational study of IPD cases notified to the Epidemiological Surveillance Network of the Autonomous Community of Madrid between 2008 and 2015. The IPD case was defined as the disease caused by Streptococcus pneumoniae, with isolation and DNA or antigen detection, in samples from normally sterile sites. The isolated strains were sent to the Regional Public Health Laboratory for identification of the serotype. Serotypes were classified according to their inclusion in the 7-valent conjugate vaccine (PCV7), in the 13-valent vaccine, but not in the 7-valent vaccine (PCV13-additional) and not included in the 13-valent vaccine (non-PCV). The Incidence Rate Ratios (IRRs) were calculated comparing the 2011-2012 and 2013-2015 periods with the 2008-2010 period. 4,307 cases were reported. 86.6% were serotyped. The IRR of IPD was 0.67 and 0.67 for all serotypes; 0.43 and 0.45 for PCV7 serotypes; 0.46 and 0.25 for PCV13-additional serotypes, and 1.01 and 1.32 for non-PCV13 serotypes in the 2011-2012 and 2013-2015 periods. The incidence of serotypes 8, 9N, 10A, 23B, 24F and serogroup 33 increased significantly in the 2013-2015 period. Serotypes 15B and 24F accounted for 24% of non-PCV13 cases in children under 5years, serotypes 8 and 9N for 51% in the population aged 5 to 59years and serotypes 8 and 22F for 25% in the population aged over 59years. The incidence of serotypes not included in conjugate vaccines has increased, especially in children under 5years, but the total incidence of IPD has decreased. It is important to continue with the epidemiological and microbiological surveillance programmes to assess the effect of vaccination on the incidence of IPD. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

CRISPR/Cas9 Genome Editing Reveals That the Intron Is Not Essential for var2csa Gene Activation or Silencing in Plasmodium falciparum.

PubMed

Bryant, Jessica M; Regnault, Clément; Scheidig-Benatar, Christine; Baumgarten, Sebastian; Guizetti, Julien; Scherf, Artur

2017-07-11

Plasmodium falciparum relies on monoallelic expression of 1 of 60 var virulence genes for antigenic variation and host immune evasion. Each var gene contains a conserved intron which has been implicated in previous studies in both activation and repression of transcription via several epigenetic mechanisms, including interaction with the var promoter, production of long noncoding RNAs (lncRNAs), and localization to repressive perinuclear sites. However, functional studies have relied primarily on artificial expression constructs. Using the recently developed P. falciparum clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system, we directly deleted the var2csa P. falciparum 3D7_1200600 (Pf3D7_1200600) endogenous intron, resulting in an intronless var gene in a natural, marker-free chromosomal context. Deletion of the var2csa intron resulted in an upregulation of transcription of the var2csa gene in ring-stage parasites and subsequent expression of the PfEMP1 protein in late-stage parasites. Intron deletion did not affect the normal temporal regulation and subsequent transcriptional silencing of the var gene in trophozoites but did result in increased rates of var gene switching in some mutant clones. Transcriptional repression of the intronless var2csa gene could be achieved via long-term culture or panning with the CD36 receptor, after which reactivation was possible with chondroitin sulfate A (CSA) panning. These data suggest that the var2csa intron is not required for silencing or activation in ring-stage parasites but point to a subtle role in regulation of switching within the var gene family. IMPORTANCE Plasmodium falciparum is the most virulent species of malaria parasite, causing high rates of morbidity and mortality in those infected. Chronic infection depends on an immune evasion mechanism termed antigenic variation, which in turn relies on monoallelic expression of 1 of ~60 var genes. Understanding antigenic variation and the transcriptional regulation of monoallelic expression is important for developing drugs and/or vaccines. The var gene family encodes the antigenic surface proteins that decorate infected erythrocytes. Until recently, studying the underlying genetic elements that regulate monoallelic expression in P. falciparum was difficult, and most studies relied on artificial systems such as episomal reporter genes. Our study was the first to use CRISPR/Cas9 genome editing for the functional study of an important, conserved genetic element of var genes-the intron-in an endogenous, episome-free manner. Our findings shed light on the role of the var gene intron in transcriptional regulation of monoallelic expression. Copyright © 2017 Bryant et al.

Complicated meningitis caused by a rare serotype of Haemophilus influenzae in Portugal.

PubMed

Calado, Rita; Betencourt, Célia; Gonçalves, Helder; Cristino, Nuno; Calhau, Paulo; Lavado, Paula Bajanca

2011-01-01

We report a case of meningitis due to Haemophilus influenzae serotype d strain in an infant. As far as we know, this is the first report of a serotype d strain, responsible for childhood invasive disease in Europe, demonstrating an emerging of H. influenzae non-b serotype, in the post-vaccination era. Copyright © 2011 Elsevier Inc. All rights reserved.

Salmonellae in Rhodesia: sources and serotypes of some isolates from abattoirs, domestic animals, birds and man.

PubMed

Chambers, P G

1977-12-01

Sources and serotypes of some salmonellae isolated from abattoirs, domestic animals, birds and man are given. At least 72 serotypes have been identified from 1273 isolations from abattoirs, animals and birds, and from 7 137 isolations from man. The sources and serotypes of these isolations are discussed and some suggestions concerning the epidemiology of Salmonella in Rhodesia are made.

The differential impact of oral poliovirus vaccine formulation choices on serotype-specific population immunity to poliovirus transmission.

PubMed

Thompson, Kimberly M; Duintjer Tebbens, Radboud J

2015-09-17

Prior analyses demonstrated the need for some countries and the Global Polio Eradication Initiative (GPEI) to conduct additional supplemental immunization activities (SIAs) with trivalent oral poliovirus vaccine (tOPV) prior to globally-coordinated cessation of all serotype 2-containing OPV (OPV2 cessation) to prevent the creation of serotype 2 circulating vaccine-derived poliovirus (cVDPV2) outbreaks after OPV2 cessation. The GPEI continues to focus on achieving and ensuring interruption of wild poliovirus serotype 1 (WPV1) and making vaccine choices that prioritize bivalent OPV (bOPV) for SIAs, nominally to increase population immunity to serotype 1, despite an aggressive timeline for OPV2 cessation. We use an existing dynamic poliovirus transmission model of northwest Nigeria and an integrated global model for long-term poliovirus risk management to explore the impact of tOPV vs. bOPV vaccine choices on population immunity and cVDPV2 risks. Using tOPV instead of bOPV for SIAs leads to a minimal decrease in population immunity to transmission of serotypes 1 and 3 polioviruses, but a significantly higher population immunity to transmission of serotype 2 polioviruses. Failure to use tOPV in enough SIAs results in cVDPV2 emergence after OPV2 cessation in both the northwest Nigeria model and the global model. Despite perceptions to the contrary, prioritizing the use of bOPV over tOPV prior to OPV2 cessation does not significantly improve serotype 1 population immunity to transmission. Immunization leaders need to focus on all three poliovirus serotypes to appropriately manage the risks of OPV cessation in the polio endgame. Focusing on population immunity to transmission to interrupt WPV1 transmission and manage pre-OPV cessation risks of cVDPVs, all countries performing poliovirus SIAs should use tOPV up until the time of OPV2 cessation, after which time they should continue to use the OPV vaccine formulation with all remaining serotypes until coordinated global cessation of those serotypes.

Fluoroquinolone-Resistant Pneumococci: Dynamics of Serotypes and Clones in Spain in 2012 Compared with Those from 2002 and 2006

PubMed Central

Domenech, Arnau; Tirado-Vélez, Jose M.; Fenoll, Asunción; Ardanuy, Carmen; Yuste, Jose; Liñares, Josefina

2014-01-01

In Spain, rates of ciprofloxacin resistance in pneumococci were low during the last decade (2.6% in 2002 and 2.3% in 2006). In 2012, the rate remained at 2.3%, equivalent to 83 of 3,621 isolates. Of the 83 resistant isolates, 15 showed a low level (MIC of 4 to 8 μg/ml) and 68 a high level (MIC of 16 to 128 μg/ml) of ciprofloxacin resistance. Thirteen low-level-resistant isolates had single changes in ParC, one had a single ParE change, and one did not present any mutations. High-level-resistant isolates had GyrA changes plus additional ParC and/or ParE changes: 51, 15, and 2 isolates had 2, 3, or 4 mutations, respectively. Although 24 different serotypes were observed, 6 serotypes accounted for 51.8% of ciprofloxacin-resistant isolates: 8 (14.5%), 19A (10.8%), 11A (7.2%), 23A (7.2%), 15A (6.0%), and 6B (6.0%). A decrease in pneumococcal 7-valent conjugate vaccine (PCV7) serotypes was observed from 2006 (35.7%) to 2012 (16.9%), especially of serotype 14 (from 16.3% to 2.4%; P < 0.001). In comparison with findings in 2006, multidrug resistance was greater in 2012 (P = 0.296), mainly due to the increased presence and/or emergence of clonal complexes associated with non-PCV7 serotypes: CC63 expressing serotypes 8, 15A, and 19A; CC320 (with serotype 19A); and CC42 (with serotype 23A). Although rates of ciprofloxacin resistance remained low and stable throughout the last decade, changes in serotype and genotype distributions were observed in 2012, notably the expansion of a preexisting multidrug-resistant clone, CC63, and the emergence of the CC156 clone expressing serotype 11A. PMID:24514095

Virulence and Draft Genome Sequence Overview of Multiple Strains of the Swine Pathogen Haemophilus parasuis

PubMed Central

Brockmeier, Susan L.; Register, Karen B.; Kuehn, Joanna S.; Nicholson, Tracy L.; Loving, Crystal L.; Bayles, Darrell O.; Shore, Sarah M.; Phillips, Gregory J.

2014-01-01

Haemophilus parasuis is the cause of Glässer's disease in swine, which is characterized by systemic infection resulting in polyserositis, meningitis, and arthritis. Investigation of this animal disease is complicated by the enormous differences in the severity of disease caused by H. parasuis strains, ranging from lethal systemic disease to subclinical carriage. To identify differences in genotype that could account for virulence phenotypes, we established the virulence of, and performed whole genome sequence analysis on, 11 H. parasuis strains. Virulence was assessed by evaluating morbidity and mortality following intranasal challenge of Caesarean-derived, colostrum-deprived (CDCD) pigs. Genomic DNA from strains Nagasaki (serotype 5), 12939 (serotype 1), SW140 (serotype 2), 29755 (serotype 5), MN-H (serotype 13), 84-15995 (serotype 15), SW114 (serotype 3), H465 (serotype 11), D74 (serotype 9), and 174 (serotype 7) was used to generate Illumina paired-end libraries for genomic sequencing and de novo assembly. H. parasuis strains Nagasaki, 12939, SH0165 (serotype 5), SW140, 29755, and MN-H exhibited a high level of virulence. Despite minor differences in expression of disease among these groups, all pigs challenged with these strains developed clinical signs consistent with Glässer's disease between 1–7 days post-challenge. H. parasuis strains 84-15995 and SW114 were moderately virulent, in that approximately half of the pigs infected with each developed Glässer's disease. H. parasuis strains H465, D74, and 174 were minimally virulent or avirulent in the CDCD pig model. Comparative genomic analysis among strains identified several noteworthy differences in coding regions. These coding regions include predicted outer membrane, metabolism, and pilin or adhesin related genes, some of which likely contributed to the differences in virulence and systemic disease observed following challenge. These data will be useful for identifying H. parasuis virulence factors and vaccine targets. PMID:25137096

Are risk factors associated with invasive pneumococcal disease according to different serotypes?

PubMed Central

Ciruela, Pilar; Soldevila, Núria; Selva, Laura; Hernández, Sergi; Garcia-Garcia, Juan Jose; Moraga, Fernando; de Sevilla, Mariona F.; Codina, Gemma; Planes, Ana Maria; Esteva, Cristina; Coll, Francis; Cardeñosa, Neus; Jordan, Iolanda; Batalla, Joan; Salleras, Luis; Muñoz-Almagro, Carmen; Domínguez, Angela

2013-01-01

The aim of this study was to investigate risk factors for the most common serotypes of invasive pneumococcal disease (IPD). A total of 293 IPD cases were analyzed in children aged 3–59 mo in a community with intermediate vaccination coverage with the 7-valent pneumococcal vaccine (PCV7). IPD cases were reviewed during 2007–2009 in two pediatric hospitals in Catalonia (Spain). A multivariate analysis using unconditional logistic regression was performed to estimate the adjusted odds ratio. PCV7 coverage was 45.4%. Pneumonia with empyema (64.5%) was the most frequent clinical manifestation. The most common serotypes were: serotype 1 (21.2%), 19A (16.0%), 3 (12.6%) and 7F/A (6.8%). 70.0% of serotypes found were included in the 13-valent conjugate vaccine (PCV13), 39.2% in the 10-valent conjugate vaccine and 8.1% in the PCV7. PCV7 was protective in IPD cases due to PCV7-serotypes (aOR: 0.15, 95% CI:0.04–0.55). Serotype 1 was positively associated with attending day care or school (aOR: 3.55, 95% CI: 1.21–10.38) and age 24–59 mo (aOR: 7.70, 95% CI:2.70–21.98). Serotype 19A was positively associated with respiratory infection in the previous month (aOR: 2.26, 95% CI: 1.03–4.94), non-penicillin susceptible IPD (aOR: 1.89, 95% CI:1.13–3.16) and negatively associated with age 24–59 mo (aOR: 0.19, 95% CI:0.09–0.41). Serotype 3 was positively associated with vaccination (aOR: 4.87, 95% CI:2.05–11.59). No factors were associated with serotype 7F/A. Vaccination with pneumococcal vaccines including more serotypes may reduce the risk of disease in our setting. PMID:23295982

Are risk factors associated with invasive pneumococcal disease according to different serotypes?

PubMed

Ciruela, Pilar; Soldevila, Núria; Selva, Laura; Hernández, Sergi; Garcia-Garcia, Juan Jose; Moraga, Fernando; de Sevilla, Mariona F; Codina, Gemma; Planes, Ana Maria; Esteva, Cristina; Coll, Francis; Cardeñosa, Neus; Jordan, Iolanda; Batalla, Joan; Salleras, Luis; Muñoz-Almagro, Carmen; Domínguez, Angela

2013-03-01

The aim of this study was to investigate risk factors for the most common serotypes of invasive pneumococcal disease (IPD). A total of 293 IPD cases were analyzed in children aged 3-59 mo in a community with intermediate vaccination coverage with the 7-valent pneumococcal vaccine (PCV7). IPD cases were reviewed during 2007-2009 in two pediatric hospitals in Catalonia (Spain). A multivariate analysis using unconditional logistic regression was performed to estimate the adjusted odds ratio. PCV7 coverage was 45.4%. Pneumonia with empyema (64.5%) was the most frequent clinical manifestation. The most common serotypes were: serotype 1 (21.2%), 19A (16.0%), 3 (12.6%) and 7F/A (6.8%). 70.0% of serotypes found were included in the 13-valent conjugate vaccine (PCV13), 39.2% in the 10-valent conjugate vaccine and 8.1% in the PCV7. PCV7 was protective in IPD cases due to PCV7-serotypes (aOR: 0.15, 95% CI:0.04-0.55). Serotype 1 was positively associated with attending day care or school (aOR: 3.55, 95% CI: 1.21-10.38) and age 24-59 mo (aOR: 7.70, 95% CI:2.70-21.98). Serotype 19A was positively associated with respiratory infection in the previous month (aOR: 2.26, 95% CI: 1.03-4.94), non-penicillin susceptible IPD (aOR: 1.89, 95% CI:1.13-3.16) and negatively associated with age 24-59 mo (aOR: 0.19, 95% CI:0.09-0.41). Serotype 3 was positively associated with vaccination (aOR: 4.87, 95% CI:2.05-11.59). No factors were associated with serotype 7F/A. Vaccination with pneumococcal vaccines including more serotypes may reduce the risk of disease in our setting.

Molecular Phylogeny of the Psittacid Herpesviruses Causing Pacheco's Disease: Correlation of Genotype with Phenotypic Expression

PubMed Central

Tomaszewski, Elizabeth K.; Kaleta, Erhard F.; Phalen, David N.

2003-01-01

Fragments of 419 bp of the UL16 open reading frame from 73 psittacid herpesviruses (PsHVs) from the United States and Europe were sequenced. All viruses caused Pacheco's disease, and serotypes of the European isolates were known. A phylogenetic tree derived from these sequences demonstrated that the PsHVs that cause Pacheco's disease comprised four major genotypes, with each genotype including between two and four variants. With the exception of two viruses, the serotypes of the virus isolates could be predicted by the genotypes. Genotypes 1 and 4 corresponded to serotype 1 isolates, genotype 2 corresponded to serotype 2 isolates, and genotype 3 corresponded to serotype 3 isolates. The single serotype 4 virus mapped to genotype 4. DNA from a virus with a unique serotype could not be amplified with primers that amplified DNA from all other PsHVs, and its classification remains unknown. Viruses representing all four genotypes were found in both the United States and Europe, and it was therefore predicted that serotypes 1, 2, and 3 were present in the United States. Serotype 4 was represented by a single European isolate that could not be genetically distinguished from serotype 1 viruses; therefore, the presence of serotype 4 in the United States could not be predicted. Viruses of genotype 4 were found to be the most commonly associated with Pacheco's disease in macaws and conures and were least likely to be isolated in chicken embryo fibroblasts in the United States. All four genotypes caused deaths in Amazon parrots, but genotype 4 was associated with Pacheco's disease only in Amazons in Europe. Genotypes 2, 3, and 4, but not 1, were found in African grey parrots. Although parrots from the Pacific distribution represent a relatively small percentage of the total number of birds with Pacheco's disease, all four genotypes were found to cause disease in these species. PMID:14512573

Virulence and draft genome sequence overview of multiple strains of the swine pathogen Haemophilus parasuis.

PubMed

Brockmeier, Susan L; Register, Karen B; Kuehn, Joanna S; Nicholson, Tracy L; Loving, Crystal L; Bayles, Darrell O; Shore, Sarah M; Phillips, Gregory J

2014-01-01

Haemophilus parasuis is the cause of Glässer's disease in swine, which is characterized by systemic infection resulting in polyserositis, meningitis, and arthritis. Investigation of this animal disease is complicated by the enormous differences in the severity of disease caused by H. parasuis strains, ranging from lethal systemic disease to subclinical carriage. To identify differences in genotype that could account for virulence phenotypes, we established the virulence of, and performed whole genome sequence analysis on, 11 H. parasuis strains. Virulence was assessed by evaluating morbidity and mortality following intranasal challenge of Caesarean-derived, colostrum-deprived (CDCD) pigs. Genomic DNA from strains Nagasaki (serotype 5), 12939 (serotype 1), SW140 (serotype 2), 29755 (serotype 5), MN-H (serotype 13), 84-15995 (serotype 15), SW114 (serotype 3), H465 (serotype 11), D74 (serotype 9), and 174 (serotype 7) was used to generate Illumina paired-end libraries for genomic sequencing and de novo assembly. H. parasuis strains Nagasaki, 12939, SH0165 (serotype 5), SW140, 29755, and MN-H exhibited a high level of virulence. Despite minor differences in expression of disease among these groups, all pigs challenged with these strains developed clinical signs consistent with Glässer's disease between 1-7 days post-challenge. H. parasuis strains 84-15995 and SW114 were moderately virulent, in that approximately half of the pigs infected with each developed Glässer's disease. H. parasuis strains H465, D74, and 174 were minimally virulent or avirulent in the CDCD pig model. Comparative genomic analysis among strains identified several noteworthy differences in coding regions. These coding regions include predicted outer membrane, metabolism, and pilin or adhesin related genes, some of which likely contributed to the differences in virulence and systemic disease observed following challenge. These data will be useful for identifying H. parasuis virulence factors and vaccine targets.

Serotype distribution and antimicrobial resistance of Streptococcus pneumoniae in children with acute bacterial meningitis in Mozambique: implications for a national immunization strategy.

PubMed

Nhantumbo, Aquino Albino; Gudo, Eduardo Samo; Caierão, Juliana; Munguambe, Alcides Moniz; Comé, Charlotte Elizabeth; Zimba, Tomás Francisco; Moraes, Milton Ozório; Dias, Cícero; Cantarelli, Vlademir Vicente

2016-06-29

S. pneumoniae is the leading cause of acute bacterial meningitis (ABM) in children. Vaccination using the 10-valent conjugate vaccine (PCV-10) was recently introduced into the National Immunization Program in Mozambique, but data on serotype coverage of this vaccine formulation are scarce. In this study, we investigated the serotype distribution and antimicrobial resistance of isolates of S. pneumoniae causing ABM in children < 5 years at the two largest hospitals in Mozambique. Between March 2013 and March 2014, a total of 352 cerebrospinal fluid (CSF) samples were collected from eligible children, of which 119 (33.8 %) were positive for S. pneumoniae. Of these, only 50 samples met the criteria for serotyping and were subsequently serotyped using sequential multiplex PCR (SM-PCR), but 15 samples were non-typable. The most common serotypes of S. pneumoniae were 1 (18.2 %), 5 (15.2 %), 14 (12.1 %), 9 V (12.1 %), 23 F (9.1 %), 6A (9.1 %), 4 (9.1 %) and 6B (6.1 %). Serotypes 1, 5, 9 V, 6A and 12 were mostly prevalent in Northern Mozambique, while serotypes 23 F, 4, 6B, 3 and 15B were predominant in Southern. Serotype coverage of PCV-10 and PCV-13 vaccine formulations were 81.8 % and 93.9 %, respectively. Serotypes 1, 3, 4, 6B, 14, 23 F were resistant to penicillin and sensitive to ceftriaxone. Our findings shows that changing the current in use PCV-10 vaccine formulation to PCV-13 formulation might increase substantially the protection against invasive strains of S. pneumoniae as the PCV-10 vaccine formulation does not cover the serotypes 3 and 6A, which are prevalent in Mozambique.

Changing epidemiology of group B streptococcal infections among adults in Iceland: 1975-2014.

PubMed

Björnsdóttir, E S; Martins, E R; Erlendsdóttir, H; Haraldsson, G; Melo-Cristino, J; Kristinsson, K G; Ramirez, M

2016-04-01

We studied the bacterial characteristics and incidence of invasive infections caused by group B streptococci (GBS) in adults in Iceland in 1975-2014. A total of 145 isolates were characterized by serotyping, antimicrobial susceptibility, multilocus sequence typing and surface protein gene profiling. Disease incidence increased during the studied period (p <0.001), reaching 2.17 cases/100 000 person-years in 2013-14. Overall, serotype Ia was the most frequently found (23%), but serotypes Ib, II, III and V showed similar prevalence (14%-17%). Although there were notable changes in the proportion of most serotypes during the study period, only the decline of serotype III was statistically supported (p = 0.003) and was reflected in a decrease of clonal complexes CC17 and CC19 that included most serotype III isolates (p <0.04). On the other hand, the increase in frequency of CC1 was caused by two lineages expressing distinct serotypes: ST1/V/alp3 and ST196/IV/eps. Underlying the relative stability of serotype Ia were major changes in the lineages expressing this serotype, with an increase in the relative importance of CC23, including both ST23/Ia/eps and ST24/Ia/bca lineages, and a decrease in CC7. Nine cases of invasive GBS disease were caused by ST7, of possible zoonotic origin. All isolates were susceptible to penicillin. Rates of erythromycin and clindamycin resistance were 8.3% and 9.7%, respectively. An over-representation of resistance solely to clindamycin was associated with the unusual lsaC gene and serotype III ST19/rib lineage (p <0.001). Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

The novel Lyme borreliosis vaccine VLA15 shows broad protection against Borrelia species expressing six different OspA serotypes.

PubMed

Comstedt, Pär; Schüler, Wolfgang; Meinke, Andreas; Lundberg, Urban

2017-01-01

We have previously shown that the Outer surface protein A (OspA) based Lyme borreliosis vaccine VLA15 induces protective immunity in mice. Herein, we report the induction of protective immunity by VLA15 with mouse models using ticks infected with B. burgdorferi (OspA serotype 1), B. afzelii (OspA serotype 2) and B. bavariensis (OspA serotype 4) or with in vitro grown B. garinii (OspA serotype 5 and 6) for challenge. For B. garinii (OspA serotype 3), we have developed a growth inhibition assay using chicken complement and functional antibodies targeting B. garinii (OspA serotype 3) could be demonstrated after immunization with VLA15. Furthermore, following three priming immunizations, a booster dose was administered five months later and the induction of immunological memory could be confirmed. Thus, the antibody titers after the booster dose were increased considerably compared to those after primary immunization. In addition, the half-lives of anti-OspA serotype specific antibodies after administration of the booster immunization were longer than after primary immunization. Taken together, we could show that VLA15 induced protection in mice against challenge with four different clinically relevant Borrelia species (B. burgdorferi, B. afzelii, B. garinii and B. bavariensis) expressing five of the six OspA serotypes included in the vaccine. The protection data is supported by functional assays showing efficacy against spirochetes expressing any of the six OspA serotypes (1 to 6). To our knowledge, this is the first time a Lyme borreliosis vaccine has been able to demonstrate such broad protection in preclinical studies. These new data provide further promise for the clinical development of VLA15 and supports our efforts to provide a new Lyme borreliosis vaccine available for global use.

Simultaneous Rapid Detection and Serotyping of Cronobacter sakazakii Serotypes O1, O2, and O3 by Using Specific Monoclonal Antibodies.

PubMed

Scharinger, Eva J; Dietrich, Richard; Kleinsteuber, Ina; Märtlbauer, Erwin; Schauer, Kristina

2016-04-01

Cronobacter sakazakii is a foodborne pathogen associated with rare but often lethal infections in neonates. Powdered infant formula (PIF) represents the most frequent source of infection. Out of the identified serotypes (O1 to O7), O1, O2, and O3 are often isolated from clinical and PIF samples. Serotype-specific monoclonal antibodies (MAbs) suitable for application in enzyme immunoassays (EIAs) for the rapid detection of C. sakazakii have not yet been developed. In this study, we created specific MAbs with the ability to bind toC. sakazakii of serotypes O1, O2, and O3. Characterization by indirect EIAs, immunofluorescence, motility assays, and immunoblotting identified lipopolysaccharide (LPS) and exopolysaccharide (EPS) as the antigenic determinants of the MAbs. The established sandwich EIAs were highly sensitive and were able to detect between 2 × 10(3)and 9 × 10(6)CFU/ml. Inclusivity tests confirmed that 93% of serotype O1 strains, 100% of O2 strains, and 87% of O3 strains were detected at low cell counts. No cross-reactivity with >100 strains of Cronobacter spp. and other Enterobacter iaceae was observed, except for that with C. sakazakii serotype O3 and Cronobacter muytjensii serotype O1. Moreover, the sandwich EIAs detected C. sakazakii in PIF samples artificially contaminated with 1 to 10 bacterial cells per 10 g of sample after 15 h of preenrichment. The use of these serotype-specific MAbs not only allows the reliable detection of C. sakazakii strains but also enables simultaneous serotyping in a simple sandwich EIA method. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Changing trends in serotypes of S. pneumoniae isolates causing invasive and non-invasive diseases in unvaccinated population in Mexico (2000-2014).

PubMed

Carnalla-Barajas, María Noemí; Soto-Noguerón, Araceli; Sánchez-Alemán, Miguel Angel; Solórzano-Santos, Fortino; Velazquez-Meza, María Elena; Echániz-Aviles, Gabriela

2017-05-01

Introduction of pneumococcal conjugate vaccines (PCV) targeted against a limited number of serotypes substantially decreased invasive (IPD) and non-invasive pneumococcal diseases (NIPD) but it was accompanied by non-vaccine type replacement disease. After 9 years of introduction of PCV in Mexico, we analyze the evidence of the indirect effects on IPD and NIPD serotype distribution among groups not targeted to receive the vaccine. From January 2000 to December 2014, pneumococcal strains isolated from IPD and NIPD cases from patients ≥5 years of age from participant hospitals of the SIREVA II (Sistema Regional de Vacunas) network were serotyped. A regression analysis was performed considering year and proportion of serotypes included in the different vaccine formulations (PCV7, PCV10 and PCV13). The slope was obtained for each regression line and their correspondent p-value. The proportion of each serotype in the pre-PCV7 and post-PCV7 periods was evaluated by χ2 test. From a total of 1147 pneumococcal strains recovered, 570 corresponded to the pre-PCV7 and 577 to the post-PCV7 periods. The proportion of vaccine serotypes included in the three PCV formulations decreased by 2.4, 2.6 and 1.3%, respectively per year during the study period. A significant increase of serotype 19A was observed in the post-vaccine period in all age groups. A percentage of annual decline of serotypes causing IPD and NIPD included in PCV was detected among groups not targeted to receive the vaccine, probably due to herd effect. Considering pneumococcal serotype distribution is a dynamic process, we highlight the importance of surveillance programs. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Microevolution of Serial Clinical Isolates of Cryptococcus neoformans var. grubii and C. gattii.

PubMed

Chen, Yuan; Farrer, Rhys A; Giamberardino, Charles; Sakthikumar, Sharadha; Jones, Alexander; Yang, Timothy; Tenor, Jennifer L; Wagih, Omar; Van Wyk, Marelize; Govender, Nelesh P; Mitchell, Thomas G; Litvintseva, Anastasia P; Cuomo, Christina A; Perfect, John R

2017-03-07

The pathogenic species of Cryptococcus are a major cause of mortality owing to severe infections in immunocompromised as well as immunocompetent individuals. Although antifungal treatment is usually effective, many patients relapse after treatment, and in such cases, comparative analyses of the genomes of incident and relapse isolates may reveal evidence of determinative, microevolutionary changes within the host. Here, we analyzed serial isolates cultured from cerebrospinal fluid specimens of 18 South African patients with recurrent cryptococcal meningitis. The time between collection of the incident isolates and collection of the relapse isolates ranged from 124 days to 290 days, and the analyses revealed that, during this period within the patients, the isolates underwent several genetic and phenotypic changes. Considering the vast genetic diversity of cryptococcal isolates in sub-Saharan Africa, it was not surprising to find that the relapse isolates had acquired different genetic and correlative phenotypic changes. They exhibited various mechanisms for enhancing virulence, such as growth at 39°C, adaptation to stress, and capsule production; a remarkable amplification of ERG11 at the native and unlinked locus may provide stable resistance to fluconazole. Our data provide a deeper understanding of the microevolution of Cryptococcus species under pressure from antifungal chemotherapy and host immune responses. This investigation clearly suggests a promising strategy to identify novel targets for improved diagnosis, therapy, and prognosis. IMPORTANCE Opportunistic infections caused by species of the pathogenic yeast Cryptococcus lead to chronic meningoencephalitis and continue to ravage thousands of patients with HIV/AIDS. Despite receiving antifungal treatment, over 10% of patients develop recurrent disease. In this study, we collected isolates of Cryptococcus from cerebrospinal fluid specimens of 18 patients at the time of their diagnosis and when they relapsed several months later. We then sequenced and compared the genomic DNAs of each pair of initial and relapse isolates. We also tested the isolates for several key properties related to cryptococcal virulence as well as for their susceptibility to the antifungal drug fluconazole. These analyses revealed that the relapsing isolates manifested multiple genetic and chromosomal changes that affected a variety of genes implicated in the pathogenicity of Cryptococcus or resistance to fluconazole. This application of comparative genomics to serial clinical isolates provides a blueprint for identifying the mechanisms whereby pathogenic microbes adapt within patients to prolong disease. Copyright © 2017 Chen et al.

Improved PCR assay for the specific detection and quantitation of Escherichia coli serotype O157 in water.

PubMed

Cho, Min Seok; Joh, Kiseong; Ahn, Tae-Young; Park, Dong Suk

2014-09-01

Escherichia coli serotype O157 is still a major global healthcare problem. However, only limited information is now available on the molecular and serological detection of pathogenic bacteria. Therefore, the development of appropriate strategies for their rapid identification and monitoring is still needed. In general, the sequence analysis based on stx, slt, eae, hlyA, rfb, and fliCh7 genes is widely employed for the identification of E. coli serotype O157; but there have been critical defects in the diagnosis and identification of E. coli serotype O157, in that they are also present in other E. coli serogroups. In this study, NCBI-BLAST searches using the nucleotide sequences of the putative regulatory protein gene from E. coli O157:H7 str. Sakai found sequence difference at the serotype level. The specific primers from the putative regulatory protein gene were designed and investigated for their sensitivity and specificity for detecting the pathogen in environment water samples. The specificity of the primer set was evaluated using genomic DNA from 8 isolates of E. coli serotype O157 and 32 other reference strains. In addition, the sensitivity and specificity of this assay were confirmed by successful identification of E. coli serotype O157 in environmental water samples. In conclusion, this study showed that the newly developed quantitative serotype-specific PCR method is a highly specific and efficient tool for the surveillance and rapid detection of high-risk E. coli serotype O157.

Pathogenesis of Salmonellosis: Salmonella Exotoxins

DTIC Science & Technology

1982-03-08

Newport; Sal. 9633 - serotype Newport; and Sal. 9186 - serotype Newport. Salmonella enteritidis serotype typhimurium strain 2000 was obtained from...7054 Table 1I CULTURE MEDIA SURVEY Salmonella enteritidis Salmonella typhimurium serotype Javiana #10016 SRlI Culture Media C H 0 Cell Factor C H 0 Cell...C r AD REPORT NUMBER 2 0 Pathogenesis of Salmonellosis: Salmonella Exotoxins Annual Progress Report (9/1/78-9/1/79) Johnny W. Peterson, Ph.D. March 8

El Niño-Southern Oscillation, local weather and occurrences of dengue virus serotypes

NASA Astrophysics Data System (ADS)

Huang, Xiaodong; Clements, Archie C. A.; Williams, Gail; Devine, Gregor; Tong, Shilu; Hu, Wenbiao

2015-11-01

Severe dengue fever is usually associated with secondary infection by a dengue virus (DENV) serotype (1 to 4) that is different to the serotype of the primary infection. Dengue outbreaks only occur following importations of DENV in Cairns, Australia. However, the majority of imported cases do not result in autochthonous transmission in Cairns. Although DENV transmission is strongly associated with the El Niño-Southern Oscillation (ENSO) climate cycle and local weather conditions, the frequency and potential risk factors of infections with the different DENV serotypes, including whether or not they differ, is unknown. This study used a classification tree model to identify the hierarchical interactions between Southern Oscillation Index (SOI), local weather factors, the presence of imported serotypes and the occurrence of the four autochthonous DENV serotypes from January 2000-December 2009 in Cairns. We found that the 12-week moving average of SOI and the 2-week moving average of maximum temperature were the most important factors influencing the variation in the weekly occurrence of the four DENV serotypes, the likelihoods of the occurrence of the four DENV serotypes may be unequal under the same environmental conditions, and occurrence may be influenced by changes in global and local environmental conditions in Cairns.

Serotype diversity of Streptococcus mutans and caries activity in children in Argentina.

PubMed

Carletto-Körber, F P; González-Ittig, R E; Jimenez, M G; Cornejo, L S

2015-09-01

The purpose of this study was to analyse the serotype distribution of S. mutans and their association with caries activity in school children from Córdoba, Argentina. Clinical examination was performed in 133 children. The dmft+DMFT and Significant Caries (SiC) indices were calculated to identify individuals with high caries activity. After DNA extractions of S. mutans strains, serotypes were determined by PCR amplifications. The median caries activity of each serotype group was compared using a non-parametric Kruskall-Wallis test. We obtained S. mutans strains from stimulated saliva of 94 children. The mean dmft+DMFT was 4.14 and the mean SiC index was 8.65. Serotype c was the most frequent (53.2%), followed by e (31.9%), f (8.5%) and k (6.4%). The comparison between the SiC and Non-Sic groups showed significant differences in the frequency of serotypes c and k. The median caries activity was non-significant in the different serotypes. The difference between the serotype frequencies detected in Argentina compared to those of other countries could be related with contrasting dietary habits. The results obtained in the present study would increase the knowledge about the epidemiology of dental caries in children from Argentina.

Toxoplasma serotype is associated with development of ocular toxoplasmosis.

PubMed

Shobab, Leila; Pleyer, Uwe; Johnsen, Joerdis; Metzner, Sylvia; James, Erick R; Torun, N; Fay, Michael P; Liesenfeld, Oliver; Grigg, Michael E

2013-11-01

Worldwide, ocular toxoplasmosis (OT) is the principal cause of posterior uveitis, a severe, life-altering disease. A Toxoplasma gondii enzyme-linked immunoassay that detects strain-specific antibodies present in serum was used to correlate serotype with disease. Toxoplasma serotypes in consecutive serum samples from German uveitis patients with OT were compared with non-OT seropositive patients with noninfectious autoimmune posterior uveitis. OT patients were tested for association of parasite serotype with age, gender, location, clinical onset, size, visual acuity, or number of lesions (mean follow-up, 3.8 years) to determine association with recurrences. A novel, nonreactive (NR) serotype was detected more frequently in serum samples of OT patients (50/114, 44%) than in non-OT patients (4/56, 7%) (odds ratio, 10.0; 95% confidence interval 3.4-40.8; P < .0001). Non-OT patients were predominantly infected with Type II strains (39/56; 70%), consistent with expected frequencies in Central Europe. Among OT patients, those with NR serotypes experienced more frequent recurrences (P = .037). Polymerase chain reaction detected parasite DNA in 8/60 OT aqueous humor specimens but failed to identify Type II strain alleles. Toxoplasma NR and Type II serotypes predominate in German OT patients. The NR serotype is associated with OT recurrences, underscoring the value of screening for management of disease.

[The occurrence of Streptococcus mutans variants in man and laboratory animals].

PubMed

Gehring, F; Karle, E J; Patz, J; Felfe, W; Bradatsch, U

1976-01-01

Numerous S. mutans strains isolated from human dental plaque and from that of rats and hamsters were classified by a well-known biochemical differentiation system for the separation of the serotypes "a to e", and by seven different biotypes (I-VII). 182 S. mutans strains from human plaque were assigned to the following serotypes: "c" = 68%, "d" = 19%, and "b" and "e" = 4% each. Serotype "a" was not found at all and 10 strains could not be classified. Out of 60 S. mutans strains from the oral cavity of rats, 85% belonged to serotype "c", while in 25 strains from hamsters serotypes "e" and "d" predominated.

Antigen analyses of serotypes of streptococcus mutans using a monoclonal antibody elaborated against serotype g polysaccharide antigen.

PubMed

Okahashi, N; Nishida, Y; Futakami, K; Hamada, S

1985-04-01

A hybridoma (F4B) which produced a monoclonal antibody (mAb) specific for serotype g carbohydrate antigen (RRg) of Streptococcus mutans 6715 was obtained. The F4B mAb cross-reacted with purified carbohydrate antigens of serotype d (RRd) and serotype h (TCAh). In immunodiffusion tests, F4B mAb produced a stable precipitin band with RRg, while the band developed between the mAb and RRd/TCAh in the cold disappeared when incubated at room temperature. The immunoprecipitin reaction between F4B mAb and RRg was strongly inhibited upon addition of lactose.

[Isolation of Haemophilus influenzae serotypes from deep sites in sick children].

PubMed

Gatti, B M; Ramirez Gronda, G A; Etchevarría, M; Vescina, C M; Varea, A M; González Ayala, S E

2004-01-01

Haemophilus influenzae (Hi) is the causative agent of several human diseases such as sepsis, meningitis, celulitis, and osteoarthritis. We investigated the isolation of Hi serotypes from sterile sites in sick children. One hundred and seventy nine strains from 146 patients were studied, period 1996-2002, at the Microbiology Laboratory, Hospital de Niños Superiora Sor María Ludovica, Argentina. The serotype distribution was:1 a, 112 b,1 c,1 d, 4 e, 3 f y 24 no typable. Since the beginning of universal Hi b vaccination in 1998, we have observed the fast decrease of serotype b and a relative increase of other serotypes.

Meningitis due to Haemophilus influenzae type f.

PubMed

Cardoso, Marta Pessoa; Pasternak, Jacyr; Giglio, Alfredo Elias; Casagrande, Rejane Rimazza Dalberto; Troster, Eduardo Juan

2013-12-01

With the decline in the rate of infections caused by Haemophilus influenzae serotype b since the widespread vaccination, non-b serotypes should be considered as potential pathogenic agents in children with invasive disease younger than 5 years old. We report the case of an immunocompetent 1-year-old boy with Haemophilus influenzae type f meningitis. The agent was identified in cerebrospinal fluid and blood cultures. Serotyping was performed by tests using polyclonal sera and confirmed by polymerase chain reaction. All Haemophilus influenzae isolates associated with invasive disease should be serotyped and notified as a way to evaluate the changes and trends in serotype distribution of this disease.

A novel strain of sacbrood virus of interest to world apiculture.

PubMed

Roberts, J M K; Anderson, D L

2014-05-01

This study has characterised a novel serotype of Sacbrood virus (SBV) infecting Apis mellifera in New Guinea that has emerged in the presence of the introduced European and Asian serotypes, which infect A. mellifera and Apis cerana, respectively. The New Guinea serotype appears to have evolved through mutation of the European serotype with no evidence of recombination between known strains, although recombination was detected in other SBV isolates from Asia. SBV was also confirmed for the first time causing disease in Apis dorsata (giant Asian honeybee) in Indonesia and found to be infected by the Asian serotype. Copyright © 2014 Elsevier Inc. All rights reserved.

Vector autoregressive model approach for forecasting outflow cash in Central Java

NASA Astrophysics Data System (ADS)

hoyyi, Abdul; Tarno; Maruddani, Di Asih I.; Rahmawati, Rita

2018-05-01

Multivariate time series model is more applied in economic and business problems as well as in other fields. Applications in economic problems one of them is the forecasting of outflow cash. This problem can be viewed globally in the sense that there is no spatial effect between regions, so the model used is the Vector Autoregressive (VAR) model. The data used in this research is data on the money supply in Bank Indonesia Semarang, Solo, Purwokerto and Tegal. The model used in this research is VAR (1), VAR (2) and VAR (3) models. Ordinary Least Square (OLS) is used to estimate parameters. The best model selection criteria use the smallest Akaike Information Criterion (AIC). The result of data analysis shows that the AIC value of VAR (1) model is equal to 42.72292, VAR (2) equals 42.69119 and VAR (3) equals 42.87662. The difference in AIC values is not significant. Based on the smallest AIC value criteria, the best model is the VAR (2) model. This model has satisfied the white noise assumption.

Systematics of Juniperus section Juniperus based on leaf essential oils and random amplified polymorphic DNAs (RAPDs).

PubMed

Adams

2000-07-01

The composition of the leaf essential oils of all the species of Juniperus in sect. Juniperus (=sect. Oxycedrus) are reported and compared (J. brevifolia, J. cedrus, J. communis, J. c. var. saxatilis, J. c. var. oblonga, J. formosana, J. oxycedrus, J. o. subsp. badia, J. o. subsp. macrocarpa, J. o. subsp. transtagana, J. rigida, J. r. subsp. conferta, J. sibirica, J. taxifolia and J. t. var. lutchuensis). In addition, DNA fingerprinting by RAPDs was utilized. Based on these data, several taxa remained at the same taxonomic level: J. brevifolia, J. cedrus, J. communis, J. c. var. saxatilis, J. formosana, J. oxycedrus, J. rigida, J. r. var. conferta, and J. taxifolia. However, several taxa exhibited considerable differentiation that warranted their recognition at the specific level: J. oblonga M.-Bieb. (=J. communis var. oblonga), J. badia H. Gay (=J. oxycedrus subsp. badia), J. macrocarpa Sibth. and Sm. (=J. oxycedrus subsp. macrocarpa), J. navicularis Gand. (=J. oxycedrus subsp. transtagana), J. sibirica Brugsd. (=J. communis var. saxatilis in part), and J. lutchuensis Koidz. (= J. taxifolia var. lutchuensis).

A Two-Dimensional Variational Analysis Method for NSCAT Ambiguity Removal: Methodology, Sensitivity, and Tuning

NASA Technical Reports Server (NTRS)

Hoffman, R. N.; Leidner, S. M.; Henderson, J. M.; Atlas, R.; Ardizzone, J. V.; Bloom, S. C.; Atlas, Robert (Technical Monitor)

2001-01-01

In this study, we apply a two-dimensional variational analysis method (2d-VAR) to select a wind solution from NASA Scatterometer (NSCAT) ambiguous winds. 2d-VAR determines a "best" gridded surface wind analysis by minimizing a cost function. The cost function measures the misfit to the observations, the background, and the filtering and dynamical constraints. The ambiguity closest in direction to the minimizing analysis is selected. 2d-VAR method, sensitivity and numerical behavior are described. 2d-VAR is compared to statistical interpolation (OI) by examining the response of both systems to a single ship observation and to a swath of unique scatterometer winds. 2d-VAR is used with both NSCAT ambiguities and NSCAT backscatter values. Results are roughly comparable. When the background field is poor, 2d-VAR ambiguity removal often selects low probability ambiguities. To avoid this behavior, an initial 2d-VAR analysis, using only the two most likely ambiguities, provides the first guess for an analysis using all the ambiguities or the backscatter data. 2d-VAR and median filter selected ambiguities usually agree. Both methods require horizontal consistency, so disagreements occur in clumps, or as linear features. In these cases, 2d-VAR ambiguities are often more meteorologically reasonable and more consistent with satellite imagery.

[Effect of Water Extracts from Rhizosphere Soil of Cultivated Astragalus membranaceus var. mongholicus on It's Seed Germination and Physiological Characteristics].

PubMed

Lang, Duo-yong; Fu, Xue-yan; Rong, Jia-wang; Zhang, Xin-hui

2015-01-01

To explore the relationship between continuous cropping obstacle and autotoxicity of Astragalus membranaceus var. mongholicus. Distilled water(CK), water extracts of rhizosphere soil(50, 100, 200 and 400 mg/mL) were applied to test their effect on early growth and physiological characteristics of Astragalus membranaceus var. mongholicus. The water extracts from rhizospher soil of cultivated Astragalus membranaceus var. mongholicus significantly increased seedling emergence rate, root length and vigor index of Astragalus membranaceus var. mongholicus seedling when at the concentration of 100 mg/mL or below, however,there was no significant effect at 200 mg/mL or higher. The water extracts from rhizosphere soil of cultivated Astragalus membranaceus var. mongholicus significantly reduced the SOD activity in Astragalus membranaceus var. mongholicus seedling at 400 mg/mL and POD activity at 200 mg/mL and 400 mg/mL,while significantly increased the MDA content. Water extracts from Astragalus membranaceus var. mongholicus rhizosphere soil significantly affected Astragalus membranaceus var. mongholicus germination and seedling growth in a concentration-dependent manner, generally, low concentrations increased the SOD and POD activity which improved seed germination and seedling growth, while high concentrations caused cell membrane damage of the seedling.

Immunological properties of the primer-independent glucosyltransferase of Streptococcus mutans serotypes d and g.

PubMed

Yamashita, Y; Shigeoka, T; Hanada, N; Takehara, T

1988-05-01

Streptococcus mutans serotype g secretes at least three kinds of glucosyltransferase with different enzymological and immunological properties. One of them is a primer-independent enzyme and seems to be the source of primer for the others, both of which are primer-dependent enzymes. Recently, we purified the primer-independent enzyme, the third glucosyltransferase in this group from S. mutans strain AHT-k serotype g. In the present study, we examined the specificity of the antiserum against the primer-independent glucosyltransferase using extracellular culture-conditioned fluids of many strains of the various serotypes of S. mutans. The antiserum cross-reacted with the extracellular culture fluids from strains of serotypes d and a, in addition to serotype g, but not with those of other serotypes, indicating that the primer-independent glucosyltransferase is secreted by the S. sobrinus and S. cricetus, but not by S. mutans and S. rattus. The antiserum did not completely inhibit the activity of the enzyme, even at more than twofold antibody excess, determined by indirect precipitation with immobilized staphylococcal protein A.

Imported dengue from 2013 Angola outbreak: Not just serotype 1 was detected.

PubMed

Abreu, Cândida; Silva-Pinto, André; Lazzara, Daniela; Sobrinho-Simões, Joana; Guimarães, João Tiago; Sarmento, António

2016-06-01

All the reports from Angola's 2013 dengue outbreak revealed serotype 1. However, previously dengue serotypes 1-4 have been reported in Africa and in 2014 serotype 4 was reported in Angola. To report dengue serotypes in patients returning from Angola during 2013 outbreak. Retrospective, cross-sectional study. We serotyped the dengue by an in house Polymerase Chain Reaction technique in randomly selected cases. From the 2013 Angola's dengue outbreak we treated 47 adult patients. None had history of past dengue. A combo kit test for dengue revealed positive NS1 antigen in 39 and IgM antibodies in 8. From 17 randomly patients tested by RNA Real Time-PCR, 11 were positive: 7 for DENV-1, 2 for DENV-2, 1 for DENV-3 (co-infected with DENV-1) and 1 for DENV-4. None had a complicated or fatal evolution. Unlike previous reports the 4 serotypes were detected, and this resulted in a different epidemiological situation, raising the risk of future outbreaks of severe dengue. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of sex, parity, and sequence variation on seroreactivity to candidate pregnancy malaria vaccine antigens.

PubMed

Oleinikov, Andrew V; Rossnagle, Eddie; Francis, Susan; Mutabingwa, Theonest K; Fried, Michal; Duffy, Patrick E

2007-07-01

Plasmodium falciparum-infected erythrocytes adhere to chondroitin sulfate A (CSA) to sequester in the human placenta, and pregnancy malaria (PM) is associated with the development of disease in and the death of both mother and child. A PM vaccine appears to be feasible, because women become protected as they develop antibodies against placental infected erythrocytes (IEs). Two IE surface molecules, VAR1CSA and VAR2CSA, bind CSA in vitro and are potential vaccine candidates. We expressed all domains of VAR1CSA and VAR2CSA as mammalian cell surface proteins, using a novel approach that allows rapid purification, immobilization, and quantification of target antigen. For serum samples from East Africa, we measured reactivity to all domains, and we examined the effects of host sex and parity, as well as the effects of parasite antigenic variation. Serum samples obtained from multigravid women had a higher reactivity to all VAR2CSA domains than did those obtained from primigravid women or from men. Conversely, serum samples obtained from men had consistently higher reactivity to VAR1CSA domains than did those obtained from gravid women. Seroreactivity was strongly influenced by antigenic variation of VAR2CSA Duffy binding-like domains. Women acquire antibodies to VAR2CSA over successive pregnancies, but they lose reactivity to VAR1CSA. Serum reactivity to VAR2CSA is variant specific, and future studies should examine the degree to which functional antibodies, such as binding-inhibition antibodies, are variant specific.

Optimizing expression of the pregnancy malaria vaccine candidate, VAR2CSA in Pichia pastoris.

PubMed

Avril, Marion; Hathaway, Marianne J; Cartwright, Megan M; Gose, Severin O; Narum, David L; Smith, Joseph D

2009-06-29

VAR2CSA is the main candidate for a vaccine against pregnancy-associated malaria, but vaccine development is complicated by the large size and complex disulfide bonding pattern of the protein. Recent X-ray crystallographic information suggests that domain boundaries of VAR2CSA Duffy binding-like (DBL) domains may be larger than previously predicted and include two additional cysteine residues. This study investigated whether longer constructs would improve VAR2CSA recombinant protein secretion from Pichia pastoris and if domain boundaries were applicable across different VAR2CSA alleles. VAR2CSA sequences were bioinformatically analysed to identify the predicted C11 and C12 cysteine residues at the C-termini of DBL domains and revised N- and C-termimal domain boundaries were predicted in VAR2CSA. Multiple construct boundaries were systematically evaluated for protein secretion in P. pastoris and secreted proteins were tested as immunogens. From a total of 42 different VAR2CSA constructs, 15 proteins (36%) were secreted. Longer construct boundaries, including the predicted C11 and C12 cysteine residues, generally improved expression of poorly or non-secreted domains and permitted expression of all six VAR2CSA DBL domains. However, protein secretion was still highly empiric and affected by subtle differences in domain boundaries and allelic variation between VAR2CSA sequences. Eleven of the secreted proteins were used to immunize rabbits. Antibodies reacted with CSA-binding infected erythrocytes, indicating that P. pastoris recombinant proteins possessed native protein epitopes. These findings strengthen emerging data for a revision of DBL domain boundaries in var-encoded proteins and may facilitate pregnancy malaria vaccine development.

Optimizing expression of the pregnancy malaria vaccine candidate, VAR2CSA in Pichia pastoris

PubMed Central

Avril, Marion; Hathaway, Marianne J; Cartwright, Megan M; Gose, Severin O; Narum, David L; Smith, Joseph D

2009-01-01

Background VAR2CSA is the main candidate for a vaccine against pregnancy-associated malaria, but vaccine development is complicated by the large size and complex disulfide bonding pattern of the protein. Recent X-ray crystallographic information suggests that domain boundaries of VAR2CSA Duffy binding-like (DBL) domains may be larger than previously predicted and include two additional cysteine residues. This study investigated whether longer constructs would improve VAR2CSA recombinant protein secretion from Pichia pastoris and if domain boundaries were applicable across different VAR2CSA alleles. Methods VAR2CSA sequences were bioinformatically analysed to identify the predicted C11 and C12 cysteine residues at the C-termini of DBL domains and revised N- and C-termimal domain boundaries were predicted in VAR2CSA. Multiple construct boundaries were systematically evaluated for protein secretion in P. pastoris and secreted proteins were tested as immunogens. Results From a total of 42 different VAR2CSA constructs, 15 proteins (36%) were secreted. Longer construct boundaries, including the predicted C11 and C12 cysteine residues, generally improved expression of poorly or non-secreted domains and permitted expression of all six VAR2CSA DBL domains. However, protein secretion was still highly empiric and affected by subtle differences in domain boundaries and allelic variation between VAR2CSA sequences. Eleven of the secreted proteins were used to immunize rabbits. Antibodies reacted with CSA-binding infected erythrocytes, indicating that P. pastoris recombinant proteins possessed native protein epitopes. Conclusion These findings strengthen emerging data for a revision of DBL domain boundaries in var-encoded proteins and may facilitate pregnancy malaria vaccine development. PMID:19563628

Knowledge, Attitude and Practice of Pregnant Women towards Varicella and Their Children’s Varicella Vaccination: Evidence from Three Distrcits in Zhejiang Province, China

PubMed Central

Hu, Yu; Chen, Yaping; Wang, Ying; Liang, Hui

2017-01-01

Background: The objectives of this study were to examine the knowledge, attitudes and practice (KAP) towards varicella and varicella vaccine (VarV) vaccination among pregnant women in three distrcits in Zhejiang Province, China. Methods: From 1 January to 31 March 2014, pregnant women with ≥12 gestational weeks were recruited and received a self-administrated questionnaire. The first dose of VarV (VarV1) vaccination status of children from present pregnancy was extracted at 24 months of age from Zhejiang provincial immunization information system (ZJIIS). Three variables was defined as the main outcomes, which included: (1) knowing about both the availability of VarV and the number of doses required; (2) positive attitude towards the utility of varicella vaccination; (3) the vaccination coverage of VarV1, which meant the proportion of children having received the VarV1. Counts and proportions were used to describe the socio-demographic characteristics of study participants, and their relationship with study outcomes were tested using chi-square tests in univariate analysis and logistic regression in multivariable analysis. Results: A total of 629 pregnant women participated in this study. The majority of the participants (68.0%) answered correctly about the transmission route of varicella. The proportion of participants who heard about varicella vaccination was 76.5% and 66.8% knew that VarV was currently available. Only 13.5% of the participants answered correctly that the complete VarV series needed two doses. Age, immigration status, education level, household income, and number of children of the pregnant women were significant predictors of the KAP regarding the VarV vaccination. Conclusions: The current survey indicated that optimal KAP levels and coverage on VarV vaccination were observed in three districts of Zhejiang Province. Health education programs on varicella and VarV vaccination directed towards both pre-natal and post-natal women are needed, which will result in a better attitude on vaccination of VarV and in a high coverage of VarV. PMID:28946647

Streptococcus mutans levels in saliva and distribution of serotypes among 9-year-old Icelandic children.

PubMed

Holbrook, W P; Beighton, D

1987-02-01

Streptococcus mutans levels in saliva were determined in 9-yr-old children from five towns in Iceland. In four towns the mean counts were greater than 10(5)/ml. Serotype c was predominant but types e and d/g were also found. The proportion of children harbouring serotype d/g alone or in combination with other serotypes was higher than that reported in most other studies.

Complete genome sequence of Streptococcus mutans GS-5, a serotype c strain.

PubMed

Biswas, Saswati; Biswas, Indranil

2012-09-01

Streptococcus mutans, a principal causative agent of dental caries, is considered to be the most cariogenic among all oral streptococci. Of the four S. mutans serotypes (c, e, f, and k), serotype c strains predominate in the oral cavity. Here, we present the complete genome sequence of S. mutans GS-5, a serotype c strain originally isolated from human carious lesions, which is extensively used as a laboratory strain worldwide.

CRISPR Typing and Subtyping for Improved Laboratory Surveillance of Salmonella Infections

PubMed Central

Fabre, Laëtitia; Zhang, Jian; Guigon, Ghislaine; Le Hello, Simon; Guibert, Véronique; Accou-Demartin, Marie; de Romans, Saïana; Lim, Catherine; Roux, Chrystelle; Passet, Virginie; Diancourt, Laure; Guibourdenche, Martine; Issenhuth-Jeanjean, Sylvie; Achtman, Mark; Brisse, Sylvain; Sola, Christophe; Weill, François-Xavier

2012-01-01

Laboratory surveillance systems for salmonellosis should ideally be based on the rapid serotyping and subtyping of isolates. However, current typing methods are limited in both speed and precision. Using 783 strains and isolates belonging to 130 serotypes, we show here that a new family of DNA repeats named CRISPR (clustered regularly interspaced short palindromic repeats) is highly polymorphic in Salmonella. We found that CRISPR polymorphism was strongly correlated with both serotype and multilocus sequence type. Furthermore, spacer microevolution discriminated between subtypes within prevalent serotypes, making it possible to carry out typing and subtyping in a single step. We developed a high-throughput subtyping assay for the most prevalent serotype, Typhimurium. An open web-accessible database was set up, providing a serotype/spacer dictionary and an international tool for strain tracking based on this innovative, powerful typing and subtyping tool. PMID:22623967

Antibody persistence and immunologic memory after sequential pneumococcal conjugate and polysaccharide vaccination in HIV-infected children on highly active antiretroviral therapy.

PubMed

Abzug, Mark J; Song, Lin Ye; Levin, Myron J; Nachman, Sharon A; Borkowsky, William; Pelton, Stephen I

2013-10-01

The capacity of pneumococcal vaccination to confer memory in HIV-infected children is critical for durable protection. HIV-infected children 2-<19 years administered two doses of pneumococcal conjugate vaccine (PCV7) and one dose of polysaccharide vaccine (PPV) on HAART were randomized 4-5 years later to receive a PCV7 or PPV booster. Total and high avidity antibodies to serotypes 1 (PPV) and 6B and 14 (PCV7 and PPV) were determined by ELISA. Memory was defined as persistence of ≥ 0.5 mcg/mL of serotype-specific antibody on day 0 or change from <0.5 mcg/mL to ≥ 0.5 mcg/mL between day 0 and week 1, or, ≥ 4-fold antibody rise between day 0 and week 1. Prior to boosting, 4-5 years after the previous PCV7-PCV7-PPV series, geometric mean concentrations (GMCs) were 0.46 mcg/mL (serotype 1), 1.31 mcg/mL (serotype 6B), and 1.47 mcg/mL (serotype 14), with concentrations ≥ 0.5 mcg/mL in 41% (serotype 1) to 82% (serotypes 6B and 14). Memory based on antibody concentration ≥ 0.5 mcg/mL before or 1 week after boosting with PCV7 or PPV was demonstrated in 42-61% for serotype 1 and 87-94% for serotypes 6B and 14, with lower rates based on day 0 to week 1 ≥ 4-fold antibody rise (serotype 1, 3-13%; serotype 6B, 13-31%; serotype 14, 29-53%). Antibody concentrations post-boosting were greater following PCV7 than PPV for serotypes 6B and 14. Ratios of highly avid to total antibody pre- and post-boosting were 0.5-0.8. Predictors of memory included higher CD4% (nadir before HAART and at P1024 and P1061s entry), CD19% (at P1024 and P1061s entry), and antibody response after the PCV7-PCV7-PPV primary series and lower viral load (at P1024 and P1061s entry) and age. Protective antibody concentrations, high avidity, and booster responses to PCV7 or PPV indicative of memory were present 4-5 years after PCV7-PCV7-PPV in HIV-infected children on HAART. Copyright © 2013 Elsevier Ltd. All rights reserved.

Antibody Persistence and Immunologic Memory after Sequential Pneumococcal Conjugate and Polysaccharide Vaccination in HIV-Infected Children on Highly Active Antiretroviral Therapy

PubMed Central

Abzug, Mark J.; Song, Lin Ye; Levin, Myron J.; Nachman, Sharon A.; Borkowsky, William; Pelton, Stephen I.

2013-01-01

Background The capacity of pneumococcal vaccination to confer memory in HIV-infected children is critical for durable protection. Methods HIV-infected children 2–<19 years administered two doses of pneumococcal conjugate vaccine (PCV7) and one dose of polysaccharide vaccine (PPV) on HAART were randomized four-five years later to receive a PCV7 or PPV booster. Total and high avidity antibodies to serotypes 1 (PPV) and 6B and 14 (PCV7 and PPV) were determined by ELISA. Memory was defined as persistence of ≥0.5 mcg/mL of serotype-specific antibody on day 0 or change from <0.5 mcg/mL to ≥0.5 mcg/mL between day 0 and week 1, or, ≥4-fold antibody rise between day 0 and week 1. Results Prior to boosting, four to five years after the previous PCV7-PCV7-PPV series, geometric mean concentrations (GMCs) were 0.46 mcg/mL (serotype 1), 1.31 mcg/mL (serotype 6B), and 1.47 mcg/mL (serotype 14), with concentrations ≥0.5 mcg/mL in 41% (serotype 1) to 82% (serotypes 6B and 14). Memory based on antibody concentration ≥0.5 mcg/mL before or 1 week after boosting with PCV7 or PPV was demonstrated in 42–61% for serotype 1 and 87–94% for serotypes 6B and 14, with lower rates based on day 0 to week 1 ≥4-fold antibody rise (serotype 1, 3–13%; serotype 6B, 13–31%; serotype 14, 29–53%). Antibody concentrations post-boosting were greater following PCV7 than PPV for serotypes 6B and 14. Ratios of highly avid to total antibody pre- and post-boosting were 0.5–0.8. Predictors of memory included higher CD4% (nadir before HAART and at P1024 and P1061s entry), CD19% (at P1024 and P1061s entry), and antibody response after the PCV7-PCV7-PPV primary series and lower viral load (at P1024 and P1061s entry) and age. Conclusions Protective antibody concentrations, high avidity, and booster responses to PCV7 or PPV indicative of memory were present four-five years after PCV7-PCV7-PPV in HIV-infected children on HAART. PMID:23954381

Surface antigens contribute differently to the pathophysiological features in serotype K1 and K2 Klebsiella pneumoniae strains isolated from liver abscesses.

PubMed

Yeh, Kuo-Ming; Chiu, Sheng-Kung; Lin, Chii-Lan; Huang, Li-Yueh; Tsai, Yu-Kuo; Chang, Jen-Chang; Lin, Jung-Chung; Chang, Feng-Yee; Siu, Leung-Kei

2016-01-01

The virulence role of surface antigens in a single serotype of Klebsiella pneumoniae strain have been studied, but little is known about whether their contribution will vary with serotype. To investigate the role of K and O antigen in hyper-virulent strains, we constructed O and K antigen deficient mutants from serotype K1 STL43 and K2 TSGH strains from patients with liver abscess, and characterized their virulence in according to the abscess formation and resistance to neutrophil phagocytosis, serum, and bacterial clearance in liver. Both of K1 and K2-antigen mutants lost their wildtype resistance to neutrophil phagocytosis and hepatic clearance, and failed to cause abscess formation. K2-antigen mutant became serum susceptible while K1-antigen mutant maintained its resistance to serum killing. The amount of glucuronic acid, indicating the amount of capsular polysaccharide (CPS, K antigen), was inversed proportional to the rate of phagocytosis. O-antigen mutant of serotype K1 strains had significantly more amount of CPS, and more resistant to neutrophil phagocytosis than its wildtype counterpart. O-antigen mutants of serotype K1 and K2 strains lost their wildtype serum resistance, and kept resistant to neutrophil phagocytosis. While both mutants lacked the same O1 antigen, O-antigen mutant of serotype K1 became susceptible to liver clearance and cause mild abscess formation, but its serotype K2 counterpart maintained these wildtype virulence. We conclude that the contribution of surface antigens to virulence of K. pneumoniae strains varies with serotypes.

Evaluation of Infectivity, Virulence and Transmission of FDMV Field Strains of Serotypes O and A Isolated In 2010 from Outbreaks in the Republic of Korea

PubMed Central

Pacheco, Juan M.; Lee, Kwang-Nyeong; Eschbaumer, Michael; Bishop, Elizabeth A.; Hartwig, Ethan J.; Pauszek, Steven J.; Smoliga, George R.; Kim, Su-Mi; Park, Jong-Hyeon; Ko, Young-Joon; Lee, Hyang-Sim; Tark, Dongseob; Cho, In-Soo; Kim, Byounghan; Rodriguez, Luis L.; Arzt, Jonathan

2016-01-01

Since the early 2000s outbreaks of foot-and-mouth disease (FMD) have been described in several previously FMD-free Asian nations, including the Republic of Korea (South Korea). One outbreak with FMD virus (FDMV) serotype A and two with serotype O occurred in South Korea in 2010/2011. The causative viruses belonged to lineages that had been spreading in South East Asia, far East and East Asia since 2009 and presented a great threat to the countries in that region. Most FMDV strains infect ruminants and pigs, as it happened during the outbreaks of FMDV serotype O in South Korea. Contrastingly, the strain of serotype A affected only ruminants. Based upon these findings, the intention of the work described in the current report was to characterize and compare the infectivity, virulence and transmission of both strains under laboratory conditions in cattle and pigs, by direct inoculation and contact exposure. As expected, FMDV serotype O was highly virulent in both cattle and swine by contact exposure and direct inoculation. Surprisingly, FMDV serotype A was highly virulent in swine, but was less infectious in cattle by contact exposure to infected swine or cattle. Interestingly, similar quantities of aerosolized FMDV RNA were detected during experiments with viruses of serotypes O and A. Specific virus-host interaction of A/SKR/2010 could affect the transmission of this strain to cattle, and this may explain in part the limited spread of the serotype A epizootic. PMID:26735130

Evaluation of Infectivity, Virulence and Transmission of FDMV Field Strains of Serotypes O and A Isolated In 2010 from Outbreaks in the Republic of Korea

DOE PAGES

Pacheco, Juan M.; Lee, Kwang -Nyeong; Eschbaumer, Michael; ...

2016-01-06

Since the early 2000s outbreaks of foot-and-mouth disease (FMD) have been described in several previously FMD-free Asian nations, including the Republic of Korea (South Korea). One outbreak with FMD virus (FDMV) serotype A and two with serotype O occurred in South Korea in 2010/2011. The causative viruses belonged to lineages that had been spreading in South East Asia, far East and East Asia since 2009 and presented a great threat to the countries in that region. Most FMDV strains infect ruminants and pigs, as it happened during the outbreaks of FMDV serotype O in South Korea. Contrastingly, the strain ofmore » serotype A affected only ruminants. Based upon these findings, the intention of the work described in the current report was to characterize and compare the infectivity, virulence and transmission of both strains under laboratory conditions in cattle and pigs, by direct inoculation and contact exposure. As expected, FMDV serotype O was highly virulent in both cattle and swine by contact exposure and direct inoculation. Surprisingly, FMDV serotype A was highly virulent in swine, but was less infectious in cattle by contact exposure to infected swine or cattle. Interestingly, similar quantities of aerosolized FMDV RNA were detected during experiments with viruses of serotypes O and A. Here, specific virus-host interaction of A/SKR/2010 could affect the transmission of this strain to cattle, and this may explain in part the limited spread of the serotype A epizootic« less

Salmonella enterica Infections in the United States and Assessment of Coefficients of Variation: A Novel Approach to Identify Epidemiologic Characteristics of Individual Serotypes, 1996-2011.

PubMed

Boore, Amy L; Hoekstra, R Michael; Iwamoto, Martha; Fields, Patricia I; Bishop, Richard D; Swerdlow, David L

2015-01-01

Despite control efforts, salmonellosis continues to cause an estimated 1.2 million infections in the United States (US) annually. We describe the incidence of salmonellosis in the US and introduce a novel approach to examine the epidemiologic similarities and differences of individual serotypes. Cases of salmonellosis in humans reported to the laboratory-based National Salmonella Surveillance System during 1996-2011 from US states were included. Coefficients of variation were used to describe distribution of incidence rates of common Salmonella serotypes by geographic region, age group and sex of patient, and month of sample isolation. During 1996-2011, more than 600,000 Salmonella isolates from humans were reported, with an average annual incidence of 13.1 cases/100,000 persons. The annual reported rate of Salmonella infections did not decrease during the study period. The top five most commonly reported serotypes, Typhimurium, Enteritidis, Newport, Heidelberg, and Javiana, accounted for 62% of fully serotyped isolates. Coefficients of variation showed the most geographically concentrated serotypes were often clustered in Gulf Coast states and were also more frequently found to be increasing in incidence. Serotypes clustered in particular months, age groups, and sex were also identified and described. Although overall incidence rates of Salmonella did not change over time, trends and epidemiological factors differed remarkably by serotype. A better understanding of Salmonella, facilitated by this comprehensive description of overall trends and unique characteristics of individual serotypes, will assist in responding to this disease and in planning and implementing prevention activities.

Decreasing incidence and changes in serotype distribution of invasive pneumococcal disease in persons aged under 18 years since introduction of 10-valent and 13-valent conjugate vaccines in Portugal, July 2008 to June 2012.

PubMed

Aguiar, S I; Brito, M J; Horacio, A N; Lopes, J P; Ramirez, M; Melo-Cristino, J

2014-03-27

The 10-valent pneumococcal conjugate vaccine (PCV10) became available in Portugal in mid-2009 and the 13-valent vaccine (PCV13) in early 2010. The incidence of invasive pneumococcal disease (IPD) in patients aged under 18 years decreased from 8.19 cases per 100,000 in 2008–09 to 4.52/100,000 in 2011–12. However, IPD incidence due to the serotypes included in the 7-valent conjugate vaccine (PCV7) in children aged under two years remained constant. This fall resulted from significant decreases in the number of cases due to: (i) the additional serotypes included in PCV10 and PCV13 (1, 5, 7F; from 37.6% to 20.6%), particularly serotype 1 in older children; and (ii) the additional serotypes included in PCV13 (3, 6A, 19A; from 31.6% to 16.2%), particularly serotype 19A in younger children. The decrease in serotype 19A before vaccination indicates that it was not triggered by PCV13 administration. The decrease of serotype 1 in all groups, concomitant with the introduction of PCV10, is also unlikely to have been triggered by vaccination, although PCVs may have intensified and supported these trends. PCV13 serotypes remain major causes of IPD, accounting for 63.2% of isolates recovered in Portugal in 2011–12, highlighting the potential role of enhanced vaccination in reducing paediatric IPD in Portugal.

Antimicrobial resistance and serotype prevalence of Salmonella isolated from dairy cattle in the southwestern United States.

PubMed

Edrington, T S; Schultz, C L; Bischoff, K M; Callaway, T R; Looper, M L; Genovese, K J; Jung, Y S; McReynolds, J L; Anderson, R C; Nisbet, D J

2004-01-01

Mature dairy cattle were sampled over a 2-year period (2001-2002) on six farms in New Mexico and Texas. Fecal samples (n = 1560) were collected via rectal palpation and cultured for Salmonella, and one isolate from each positive sample was serotyped. Three isolates of each serotype, with the exception of Salmonella Newport (n = 12), were examined for susceptibility to 17 antimicrobial agents. Twenty-two different serotypes were identified from a total of 393 Salmonella isolates. Montevideo was the predominant serotype (27%) followed by Mbandaka (15%), Senftenberg (11.4%), Newport (6.4%), Anatum (4.8%), and Give (4.8%). Salmonella Typhimurium and Dublin, two frequently reported serotypes, accounted for only 1% of the observed serotypes in this study. Sixty-four percent of the serotypes were susceptible to all 17 antimicrobials, 14% were resistant to a single agent, and 22% were multiresistant (2-11 types of resistance). All isolates tested were susceptible to amikacin, apramycin, imipenem, ceftriaxone, nalidixic acid, and ciprofloxacin. The most frequent types of resistance were to sulfamethoxazole, tetracycline, streptomycin, kanamycin, chloramphenicol, and ampicillin (ranging from 8.9 to 22.4%). Serotypes demonstrating multiple resistance included Dublin and Give (resistant to three or more antibiotics), Typhimurium (resistant to five antibiotics), and Newport (four and two isolates resistant to six and nine antibiotics, respectively). Class 1 integrons were present in only two Salmonella Dublin isolates and one Salmonella Newport isolate. The most prevalent resistance patterns observed in this study were toward antimicrobial agents commonly used in cattle, while all Salmonella isolates were susceptible to ceftriaxone and ciprofloxacin, antibiotics used in human medicine.

Evaluation of Infectivity, Virulence and Transmission of FDMV Field Strains of Serotypes O and A Isolated In 2010 from Outbreaks in the Republic of Korea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pacheco, Juan M.; Lee, Kwang -Nyeong; Eschbaumer, Michael

Since the early 2000s outbreaks of foot-and-mouth disease (FMD) have been described in several previously FMD-free Asian nations, including the Republic of Korea (South Korea). One outbreak with FMD virus (FDMV) serotype A and two with serotype O occurred in South Korea in 2010/2011. The causative viruses belonged to lineages that had been spreading in South East Asia, far East and East Asia since 2009 and presented a great threat to the countries in that region. Most FMDV strains infect ruminants and pigs, as it happened during the outbreaks of FMDV serotype O in South Korea. Contrastingly, the strain ofmore » serotype A affected only ruminants. Based upon these findings, the intention of the work described in the current report was to characterize and compare the infectivity, virulence and transmission of both strains under laboratory conditions in cattle and pigs, by direct inoculation and contact exposure. As expected, FMDV serotype O was highly virulent in both cattle and swine by contact exposure and direct inoculation. Surprisingly, FMDV serotype A was highly virulent in swine, but was less infectious in cattle by contact exposure to infected swine or cattle. Interestingly, similar quantities of aerosolized FMDV RNA were detected during experiments with viruses of serotypes O and A. Here, specific virus-host interaction of A/SKR/2010 could affect the transmission of this strain to cattle, and this may explain in part the limited spread of the serotype A epizootic« less

[Prevalence of Candida albican serotypes in blood isolates in Chile, and first report of Candida dubliniensis candidemia].

PubMed

Silva, Víctor; Cabrera, Macarena; Díaz, María Cristina; Abarca, Claudia; Hermosilla, Germán

2003-06-01

Our main goal was to determine the prevalence of C. albicans serotypes isolates from blood cultures and identify the presence of C. dubliniensis. We studied 47 strains identified as C. albicans by conventional methods, 28 were isolated from children and 19 from adult patients. The strains were re-identified by standard methods and phenotypic screening as xylose assimilation and growth at 42 degrees C. API ID 32C (bioMérieux) was employed with the C. dubliniensis suspected strains and confirmation was made by molecular fingerprinting using random amplified polymorphic DNA (RAPD). The C. albicans serotype was determined by agglutination with antiserum anti-antigen 6 from cell wall (Candida Check, Iatron Inc., Japan) and the in vitro susceptibilities were evaluated by a microdilution method. From 47 strains, 46 were confirmed as C. albicans, 31 of them (67%) were serotype A. Adult patients presented a high prevalence of serotype A (95%) and children presented a frequency of 52% of the serotype B (p<0.05). We confirmed the identification of C. dubliniensis in one strain isolated from an infant. All serotype B strains were susceptible to fluconazole, itraconazole and amphotericin B. On the other hand, 3% and 6% of serotype A strains were "susceptible dose dependent" to fluconazole and itraconazole, respectively. C. albicans serotype A was predominant in adult candidemia and its distribution was homogenous in children patients. All strains were highly susceptible to antifungals. We report here the first case of C. dubliniensis candidemia in South America.

Molecular diagnostics and ITS-based phylogenic analysis of Streptococcus suis serotype 2 in central Vietnam.

PubMed

Nguyen, Bach Hoang; Phan, Dieu Hong Nu; Nguyen, Hien Xuan; Le, An Van; Alberti, Alberto

2015-07-04

Streptococcus suis (S. suis) serotype 2 has recently become the most prevalent cause of meningitis in adults in many areas of Vietnam. This study provides data on S. suis molecular diagnosis in central Vietnam using a real-time polymerase chain reaction (PCR) assay targeting the S. suis serotype 2 cps2J gene. Additionally, 16S-23S rDNA intragenic spacer (ITS)-based phylogenic analysis of strains isolated from cerebrospinal fluid (CSF) in Thua Thien Hue Province, Vietnam, is presented and discussed. Pathogenic bacteria were isolated from 40 CSF samples, and 18 were identified as S. suis by culture-dependent methods. Capsular serotyping was assessed by real-time PCR. ITS sequences were obtained after traditional PCR and were used in phylogenic analyses. Pathogenic bacteria were isolated from 36 out of 40 CSF samples. A total of 18 S. suis strains were isolated and assigned to serotype 2 by real-time PCR. One CSF sample, negative when tested by culture-dependent methods, was positive to S. suis serotype 2 by real-time PCR. Pairwise alignments of the 18 ITS sequences did not reveal any variable nucleotide position, and resulted in a single sequence type. Sequences were similar to S. suis serotype 2 reference ITS sequences (> 98.1%), and there was no lack of an ITS spacer region in the isolates. S. suis serotype 2 is the most prevalent serotype in central Vietnam. Real-time PCR assay proved to be a reliable diagnostic method for early detection of S. suis 2 in CSF samples.

Application of the thermofluor PaSTRy technique for improving foot-and-mouth disease virus vaccine formulation.

PubMed

Kotecha, Abhay; Zhang, Fuquan; Juleff, Nicholas; Jackson, Terry; Perez, Eva; Stuart, Dave; Fry, Elizabeth; Charleston, Bryan; Seago, Julian

2016-07-01

Foot-and-mouth disease (FMD) has a major economic impact throughout the world and is a considerable threat to food security. Current FMD virus (FMDV) vaccines are made from chemically inactivated virus and need to contain intact viral capsids to maximize efficacy. FMDV exists as seven serotypes, each made up by a number of constantly evolving subtypes. A lack of immunological cross-reactivity between serotypes and between some strains within a serotype greatly complicates efforts to control FMD by vaccination. Thus, vaccines for one serotype do not afford protection against the others, and multiple-serotype-specific vaccines are required for effective control. The FMDV serotypes exhibit variation in their thermostability, and the capsids of inactivated preparations of the O, C and SAT serotypes are particularly susceptible to dissociation at elevated temperature. Methods to quantify capsid stability are currently limited, lack sensitivity and cannot accurately reflect differences in thermostability. Thus, new, more sensitive approaches to quantify capsid stability would be of great value for the production of more stable vaccines and to assess the effect of production conditions on vaccine preparations. Here we have investigated the application of a novel methodology (termed PaSTRy) that utilizes an RNA-binding fluorescent dye and a quantitative (q)PCR machine to monitor viral genome release and hence dissociation of the FMDV capsid during a slow incremental increase in temperature. PaSTRy was used to characterize capsid stability of all FMDV serotypes. Furthermore, we have used this approach to identify stabilizing factors for the most labile FMDV serotypes.

Application of the thermofluor PaSTRy technique for improving foot-and-mouth disease virus vaccine formulation

PubMed Central

Kotecha, Abhay; Zhang, Fuquan; Juleff, Nicholas; Jackson, Terry; Perez, Eva; Stuart, Dave; Fry, Elizabeth; Charleston, Bryan

2016-01-01

Foot-and-mouth disease (FMD) has a major economic impact throughout the world and is a considerable threat to food security. Current FMD virus (FMDV) vaccines are made from chemically inactivated virus and need to contain intact viral capsids to maximize efficacy. FMDV exists as seven serotypes, each made up by a number of constantly evolving subtypes. A lack of immunological cross-reactivity between serotypes and between some strains within a serotype greatly complicates efforts to control FMD by vaccination. Thus, vaccines for one serotype do not afford protection against the others, and multiple-serotype-specific vaccines are required for effective control. The FMDV serotypes exhibit variation in their thermostability, and the capsids of inactivated preparations of the O, C and SAT serotypes are particularly susceptible to dissociation at elevated temperature. Methods to quantify capsid stability are currently limited, lack sensitivity and cannot accurately reflect differences in thermostability. Thus, new, more sensitive approaches to quantify capsid stability would be of great value for the production of more stable vaccines and to assess the effect of production conditions on vaccine preparations. Here we have investigated the application of a novel methodology (termed PaSTRy) that utilizes an RNA-binding fluorescent dye and a quantitative (q)PCR machine to monitor viral genome release and hence dissociation of the FMDV capsid during a slow incremental increase in temperature. PaSTRy was used to characterize capsid stability of all FMDV serotypes. Furthermore, we have used this approach to identify stabilizing factors for the most labile FMDV serotypes. PMID:27002540

Outbreak-associated Salmonella enterica Serotypes and Food Commodities, United States, 1998–2008

PubMed Central

Griffin, Patricia M.; Cole, Dana; Walsh, Kelly A.; Chai, Shua J.

2013-01-01

Salmonella enterica infections are transmitted not only by animal-derived foods but also by vegetables, fruits, and other plant products. To clarify links between Salmonella serotypes and specific foods, we examined the diversity and predominance of food commodities implicated in outbreaks of salmonellosis during 1998–2008. More than 80% of outbreaks caused by serotypes Enteritidis, Heidelberg, and Hadar were attributed to eggs or poultry, whereas >50% of outbreaks caused by serotypes Javiana, Litchfield, Mbandaka, Muenchen, Poona, and Senftenberg were attributed to plant commodities. Serotypes Typhimurium and Newport were associated with a wide variety of food commodities. Knowledge about these associations can help guide outbreak investigations and control measures. PMID:23876503

Genetic and serological identification of three Vibrio parahaemolyticus strains as candidates for novel provisional O serotypes.

PubMed

Guo, Xi; Liu, Bin; Chen, Min; Wang, Yuanyuan; Wang, Lu; Chen, Hongyou; Wang, Yao; Tu, Lihong; Zhang, Xi; Feng, Lu

2017-03-20

Vibrio parahaemolyticus is a Gram-negative, halophilic Vibrio that naturally inhabits marine and estuarine environments worldwide and has recently been recognized as one of the most important foodborne pathogens. To date, 13 O serotypes and 71 K serotypes of V. parahaemolyticus have been identified. However, untypeable V. parahaemolyticus strains are frequently found during routine detection, indicating that other forms of serotypes exist and suggesting the necessity for extension of the antigenic scheme. In this work, through the genetic analysis of the O serotype genetic determinants (OGDs) and the production of antisera and serological tests, we identified three novel O serotypes of V. parahaemolyticus. Further analyses showed that recombination and gene-set deletions/insertions within OGDs may play key roles in the generation of V. parahaemolyticus O serotype diversity. A PCR method was developed for the identification of these novel O serotypes, and specificity and sensitivity were evaluated. A double-blind test including 283 clinical isolates was performed, giving perfect correlation with the agglutination test results. Generally, our study expanded the O-antigenic scheme of V. parahaemolyticus from 13 to 16 and provided a tool with the potential for the detection and identification of V. parahaemolyticus strains (especially untypeable strains) isolated from both the clinic and the environment. Copyright © 2017 Elsevier B.V. All rights reserved.

Incidence and duration of group B Streptococcus by serotype among male and female college students living in a single dormitory.

PubMed

Foxman, Betsy; Gillespie, Brenda; Manning, Shannon D; Howard, Laura J; Tallman, Patricia; Zhang, Lixin; Marrs, Carl F

2006-03-15

Group B Streptococcus causes a variety of morbid and sometimes fatal conditions affecting individuals of all age groups. There are nine known serotypes of this Gram-positive coccus but few estimates of the incidence and duration of its colonization and none by serotype in the literature. In 2001, the authors conducted a prospective cohort study among 257 men and women living in a single dormitory in Ann Arbor, Michigan. The 3-week incidence with any serotype was 11.3% (+/-3.9%) among women and 8.8% (+/-3.0%) among men; 3-week incidence rates were highest for serotype V (4.7% for women and 3.5% for men) and type Ia (2.3% for women and 2.4% for men), with no significant differences by gender. The estimated average duration of any group B Streptococcus colonization was longer for women (13.7 weeks) than men (8.5 weeks); serotype Ia was carried an average of 6.5 weeks longer in women, and serotype III was carried 4.9 weeks longer. Colonization with more than one serotype occurred significantly less than would be expected by chance (p < 0.001). Based on the overall incidence, transmission occurred between roommate pairs at the rate expected. Group B Streptococcus colonization is frequent and dynamic, but it is not transmitted by casual contact.

Rise of multidrug-resistant non-vaccine serotype 15A Streptococcus pneumoniae in the United Kingdom, 2001 to 2014

PubMed Central

Sheppard, Carmen; Fry, Norman K.; Mushtaq, Shazad; Woodford, Neil; Reynolds, Rosy; Janes, Regina; Pike, Rachel; Hill, Robert; Kimuli, Maimuna; Staves, Peter; Doumith, Michel; Harrison, Timothy; Livermore, David M

2016-01-01

Conjugate vaccines have reduced pneumococcal disease in vaccinated children and unvaccinated adults, but non-vaccine serotypes are of concern, particularly if antibiotic resistant. We reviewed Streptococcus pneumoniae collected via: (i) the British Society for Antimicrobial Chemotherapy (BSAC) surveillances from 2001–2014; (ii) Public Health England’s (PHE) invasive isolate surveillance from 2005–2014 and (iii) referral to PHE for resistance investigation from 2005–2014. Serotype 15A increased in all series, with many representatives showing triple resistance to macrolides, tetracyclines and penicillin. 15A was consistently among the 10 most prevalent serotypes from 2011 in PHE and BSAC invasive isolate/bacteraemia surveillance but never previously; 26–33% of these invasive 15A isolates had triple resistance. BSAC respiratory isolates were only serotyped in 2013/14 and 2014/15 (October to September); 15A was most prevalent serotype in both periods, comprising 9–11% of isolates, 38–48% of them with triple resistance. Serotype 15A represented 0–4% of S. pneumoniae referred to PHE for reference investigation annually until 2008 but rose to 29% (2013) and 32% (2014). Almost all multidrug-resistant 15A isolates were sequence type (ST) 63 variants, whereas susceptible 15A isolates were clonally diverse. The rise of serotype 15A suggests that pneumococcal conjugate vaccines will need ongoing adaptation. PMID:28006650

Superinfection interference between dengue-2 and dengue-4 viruses in Aedes aegypti mosquitoes.

PubMed

Muturi, Ephantus J; Buckner, Eva; Bara, Jeffrey

2017-04-01

Dengue virus consists of four antigenically distinct serotypes (DENV 1-4) that are transmitted to humans by Aedes aegypti and Aedes albopictus mosquitoes. In many dengue-endemic regions, co-circulation of two or more DENV serotypes is fairly common increasing the likelihood for exposure of the two vectors to multiple serotypes. We used a model system of DENV-2 and DENV-4 to investigate how prior exposure of Aedes aegypti to one DENV serotype affects its susceptibility to another serotype. Aedes aegypti mosquitoes were sequentially infected with DENV-2 and DENV-4 and the infection and dissemination rates for each virus determined. We found that prior infection of Ae. aegypti mosquitoes with DENV-4 rendered them significantly less susceptible to secondary infection with DENV-2. Although the results were not statistically significant, mosquitoes infected with DENV-2 were also less susceptible to secondary infection with DENV-4. The midgut dissemination and population dissemination rates for DENV-2 were significantly higher than those of DENV-4 when either virus was administered 7 days after administration of either a non-infectious blood meal or a blood meal containing a heterologous dengue serotype. These results demonstrate that superinfection interference between DENV serotypes is possible within Ae. aegypti mosquitoes, but its effect on DENV epidemiology may be dependent on the fitness of interacting serotypes. © 2017 John Wiley & Sons Ltd.

Serotypes, antibiotic susceptibilities, and multi-locus sequence type profiles of Streptococcus agalactiae isolates circulating in Beijing, China.

PubMed

Wang, Ping; Tong, Jing-jing; Ma, Xiu-hua; Song, Feng-li; Fan, Ling; Guo, Cui-mei; Shi, Wei; Yu, Sang-jie; Yao, Kai-hu; Yang, Yong-hong

2015-01-01

To investigate the serotypes, antibiotic susceptibilities, and multi-locus sequence type (MLST) profiles of Streptococcus agalactiae (S. agalactiae) in Beijing to provide references for the prevention and treatment of S. agalactiae infections. All isolates were identified using the CAMP test and the latex-agglutination assay and serotyped using a Strep-B-Latex kit, after which they were assessed for antibiotic susceptibility, macrolide-resistance genes, and MLST profiles. In total, 56 S. agalactiae isolates were identified in 863 pregnant women (6.5%). Serotypes Ia, Ib, II, III, and V were identified, among which types III (32.1%), Ia (17.9%), Ib (16.1%), and V (14.3%) were the predominant serotypes. All isolates were susceptible to penicillin and ceftriaxone. The nonsusceptiblity rates measured for erythromycin, clarithromycin, azithromycin, telithromycin, clindamycin, tetracycline, and levofloxacin were 85.7%, 92.9%, 98.2%, 30.4%, 73.2%, 91%, and 39.3%, respectively. We identified 14 sequence types (STs) for the 56 isolates, among which ST19 (30.4%) was predominant. The rate of fluoroquinolone resistance was higher in serotype III than in the other serotypes. Among the 44 erythromycin-resistant isolates, 32 (72.7%) carried ermB. S. agalactiae isolates of the serotypes Ia, Ib, III, and V are common in Beijing. Among the S. agalactiae isolates, the macrolide and clindamycin resistance rates are extremely high. Most of the erythromycin-resistant isolates carry ermB.

Toxoplasma Serotype Is Associated With Development of Ocular Toxoplasmosis

PubMed Central

Shobab, Leila; Pleyer, Uwe; Johnsen, Joerdis; Metzner, Sylvia; James, Erick R.; Torun, N.; Fay, Michael P.; Liesenfeld, Oliver; Grigg, Michael E.

2013-01-01

Background. Worldwide, ocular toxoplasmosis (OT) is the principal cause of posterior uveitis, a severe, life-altering disease. A Toxoplasma gondii enzyme-linked immunoassay that detects strain-specific antibodies present in serum was used to correlate serotype with disease. Methods. Toxoplasma serotypes in consecutive serum samples from German uveitis patients with OT were compared with non-OT seropositive patients with noninfectious autoimmune posterior uveitis. OT patients were tested for association of parasite serotype with age, gender, location, clinical onset, size, visual acuity, or number of lesions (mean follow-up, 3.8 years) to determine association with recurrences. Results. A novel, nonreactive (NR) serotype was detected more frequently in serum samples of OT patients (50/114, 44%) than in non-OT patients (4/56, 7%) (odds ratio, 10.0; 95% confidence interval 3.4–40.8; P < .0001). Non-OT patients were predominantly infected with Type II strains (39/56; 70%), consistent with expected frequencies in Central Europe. Among OT patients, those with NR serotypes experienced more frequent recurrences (P = .037). Polymerase chain reaction detected parasite DNA in 8/60 OT aqueous humor specimens but failed to identify Type II strain alleles. Conclusions. Toxoplasma NR and Type II serotypes predominate in German OT patients. The NR serotype is associated with OT recurrences, underscoring the value of screening for management of disease. PMID:23878321

The Drosophila Su(var)3-7 gene is required for oogenesis and female fertility, genetically interacts with piwi and aubergine, but impacts only weakly transposon silencing.

PubMed

Basquin, Denis; Spierer, Anne; Begeot, Flora; Koryakov, Dmitry E; Todeschini, Anne-Laure; Ronsseray, Stéphane; Vieira, Cristina; Spierer, Pierre; Delattre, Marion

2014-01-01

Heterochromatin is made of repetitive sequences, mainly transposable elements (TEs), the regulation of which is critical for genome stability. We have analyzed the role of the heterochromatin-associated Su(var)3-7 protein in Drosophila ovaries. We present evidences that Su(var)3-7 is required for correct oogenesis and female fertility. It accumulates in heterochromatic domains of ovarian germline and somatic cells nuclei, where it co-localizes with HP1. Homozygous mutant females display ovaries with frequent degenerating egg-chambers. Absence of Su(var)3-7 in embryos leads to defects in meiosis and first mitotic divisions due to chromatin fragmentation or chromosome loss, showing that Su(var)3-7 is required for genome integrity. Females homozygous for Su(var)3-7 mutations strongly impair repression of P-transposable element induced gonadal dysgenesis but have minor effects on other TEs. Su(var)3-7 mutations reduce piRNA cluster transcription and slightly impact ovarian piRNA production. However, this modest piRNA reduction does not correlate with transposon de-silencing, suggesting that the moderate effect of Su(var)3-7 on some TE repression is not linked to piRNA production. Strikingly, Su(var)3-7 genetically interacts with the piwi and aubergine genes, key components of the piRNA pathway, by strongly impacting female fertility without impairing transposon silencing. These results lead us to propose that the interaction between Su(var)3-7 and piwi or aubergine controls important developmental processes independently of transposon silencing.

National Survey of Shiga Toxin-Producing Escherichia coli Serotypes O26, O45, O103, O111, O121, O145, and O157 in Australian Beef Cattle Feces.

PubMed

Mellor, Glen E; Fegan, Narelle; Duffy, Lesley L; McMILLAN, Kate E; Jordan, David; Barlow, Robert S

2016-11-01

Escherichia coli O157 and six non-O157 Shiga toxin-producing E. coli (STEC) serotypes (O26, O45, O103, O111, O121, and O145, colloquially referred to as the "big 6") have been classified as adulterants of raw nonintact beef products in the United States. While beef cattle are a known reservoir for the prototype STEC serotype, E. coli O157, less is known about the dissemination of non-O157 STEC serotypes in Australian cattle. In the present study, 1,500 fecal samples were collected at slaughter from adult (n =628) and young (n =286) beef cattle, adult (n =128) and young (n =143) dairy cattle, and veal calves (n = 315) across 31 Australian export-registered processing establishments. Fecal samples were enriched and tested for E. coli O157 and the big 6 STEC serotypes using BAX System PCR and immunomagnetic separation methods. Pathogenic STEC (pSTEC; isolates that possess stx, eae, and an O antigen marker for O157 or a big 6 serotype) were isolated from 115 samples (7.7%), of which 100 (6.7%) contained E. coli O157 and 19 (1.3%) contained a big 6 serotype. Four of the 115 samples contained multiple pSTEC serotypes. Among samples confirmed for big 6 pSTEC, 15 (1%) contained E. coli O26 and 4 (0.3%) contained E. coli O111. pSTEC of serotypes O45, O103, O121, and O145 were not isolated from any sample, even though genes indicative of E. coli belonging to these serotypes were detected by PCR. Analysis of animal classes revealed a higher pSTEC prevalence in younger animals, including veal (12.7%), young beef (9.8%), and young dairy (7.0%), than in adult animals, including adult beef (5.1%) and adult dairy (3.9%). This study is the largest of its kind undertaken in Australia. In contrast to E. coli O157 and consistent with previous findings, this study reports a relatively low prevalence of big 6 pSTEC serotypes in Australian cattle populations.

Nucleotide substitutions in dengue virus serotypes from Asian and American countries: insights into intracodon recombination and purifying selection

PubMed Central

2013-01-01

Background Dengue virus (DENV) infection represents a significant public health problem in many subtropical and tropical countries. Although genetically closely related, the four serotypes of DENV differ in antigenicity for which cross protection among serotypes is limited. It is also believed that both multi-serotype infection as well as the evolution of viral antigenicity may have confounding effects in increased dengue epidemics. Numerous studies have been performed that investigated genetic diversity of DENV, but the precise mechanism(s) of dengue virus evolution are not well understood. Results We investigated genome-wide genetic diversity and nucleotide substitution patterns in the four serotypes among samples collected from different countries in Asia and Central and South America and sequenced as part of the Genome Sequencing Center for Infectious Diseases at the Broad Institute. We applied bioinformatics, statistical and coalescent simulation methods to investigate diversity of codon sequences of DENV samples representing the four serotypes. We show that fixation of nucleotide substitutions is more prominent among the inter-continental isolates (Asian and American) of serotypes 1, 2 and 3 compared to serotype 4 isolates (South and Central America) and are distributed in a non-random manner among the genes encoded by the virus. Nearly one third of the negatively selected sites are associated with fixed mutation sites within serotypes. Our results further show that of all the sites showing evidence of recombination, the majority (~84%) correspond to sites under purifying selection in the four serotypes. The analysis further shows that genetic recombination occurs within specific codons, albeit with low frequency (< 5% of all recombination sites) throughout the DENV genome of the four serotypes and reveals significant enrichment (p < 0.05) among sites under purifying selection in the virus. Conclusion The study provides the first evidence for intracodon recombination in DENV and suggests that within codons, genetic recombination has a significant role in maintaining extensive purifying selection of DENV in natural populations. Our study also suggests that fixation of beneficial mutations may lead to virus evolution via translational selection of specific sites in the DENV genome. PMID:23410119

Detection of dengue virus serotypes 1, 2 and 3 in selected regions of Kenya: 2011-2014.

PubMed

Konongoi, Limbaso; Ofula, Victor; Nyunja, Albert; Owaka, Samuel; Koka, Hellen; Makio, Albina; Koskei, Edith; Eyase, Fredrick; Langat, Daniel; Schoepp, Randal J; Rossi, Cynthia Ann; Njeru, Ian; Coldren, Rodney; Sang, Rosemary

2016-11-04

Dengue fever, a mosquito-borne disease, is associated with illness of varying severity in countries in the tropics and sub tropics. Dengue cases continue to be detected more frequently and its geographic range continues to expand. We report the largest documented laboratory confirmed circulation of dengue virus in parts of Kenya since 1982. From September 2011 to December 2014, 868 samples from febrile patients were received from hospitals in Nairobi, northern and coastal Kenya. The immunoglobulin M enzyme linked immunosorbent assay (IgM ELISA) was used to test for the presence of IgM antibodies against dengue, yellow fever, West Nile and Zika. Reverse transcription polymerase chain reaction (RT-PCR) utilizing flavivirus family, yellow fever, West Nile, consensus and sero type dengue primers were used to detect acute arbovirus infections and determine the infecting serotypes. Representative samples of PCR positive samples for each of the three dengue serotypes detected were sequenced to confirm circulation of the various dengue serotypes. Forty percent (345/868) of the samples tested positive for dengue by either IgM ELISA (14.6 %) or by RT-PCR (25.1 %). Three dengue serotypes 1-3 (DENV1-3) were detected by serotype specific RT-PCR and sequencing with their numbers varying from year to year and by region. The overall predominant serotype detected from 2011-2014 was DENV1 accounting for 44 % (96/218) of all the serotypes detected, followed by DENV2 accounting for 38.5 % (84/218) and then DENV3 which accounted for 17.4 % (38/218). Yellow fever, West Nile and Zika was not detected in any of the samples tested. From 2011-2014 serotypes 1, 2 and 3 were detected in the Northern and Coastal parts of Kenya. This confirmed the occurrence of cases and active circulation of dengue in parts of Kenya. These results have documented three circulating serotypes and highlight the need for the establishment of active dengue surveillance to continuously detect cases, circulating serotypes, and determine dengue fever disease burden in the country and region.

Assessing risk profiles for Salmonella serotypes in breeding pig operations in Portugal using a Bayesian hierarchical model.

PubMed

Correia-Gomes, Carla; Economou, Theodoros; Mendonça, Denisa; Vieira-Pinto, Madalena; Niza-Ribeiro, João

2012-11-21

The EU Regulation No 2160/2003 imposes a reduction in the prevalence of Salmonella in pigs. The efficiency of control programmes for Salmonella in pigs, reported among the EU Member States, varies and definitive eradication seems very difficult. Control measures currently recommended for Salmonella are not serotype-specific. Is it possible that the risk factors for different Salmonella serotypes are different? The aim of this study was to investigate potential risk factors for two groups of Salmonella sp serotypes using pen faecal samples from breeding pig holdings representative of the Portuguese pig sector. The data used come from the Baseline Survey for the Prevalence of Salmonella in breeding pigs in Portugal. A total of 1670 pen faecal samples from 167 herds were tested, and 170 samples were positive for Salmonella. The presence of Salmonella in each sample (outcome variable) was classified in three categories: i) no Salmonella, ii) Salmonella Typhimurium or S. Typhimurium-like strains with the antigenic formula: 1,4,5,12:i:-, , and iii) other serotypes. Along with the sample collection, a questionnaire concerning herd management and potential risk factors was utilised. The data have a "natural" hierarchical structure so a categorical multilevel analysis of the dataset was carried out using a Bayesian hierarchical model. The model was estimated using Markov Chain Monte Carlo methods, implemented in the software WinBUGS. The significant associations found (when compared to category "no Salmonella"), for category "serotype Typhimurium or S. Typhimurium-like strains with the antigenic formula: 1,4,5,12:i:-" were: age of breeding sows, size of the herd, number of pigs/pen and source of semen. For the category "other serotypes" the significant associations found were: control of rodents, region of the country, source of semen, breeding sector room and source of feed. The risk factors significantly associated with Salmonella shedding from the category "serotype Typhimurium or serotype 1,4,5,12:i:-" were more related to animal factors, whereas those associated with "other serotypes" were more related to environmental factors. Our findings suggest that different control measures could be used to control different Salmonella serotypes in breeding pigs.

Genetic relatedness among human rotavirus genes coding for VP7, a major neutralization protein, and its application to serotype identification.

PubMed Central

Midthun, K; Flores, J; Taniguchi, K; Urasawa, S; Kapikian, A Z; Chanock, R M

1987-01-01

Antigenic characterization of human rotaviruses by plaque reduction neutralization assay has revealed four distinct serotypes. The outer capsid protein VP7, coded for by gene 8 or 9, is a major neutralization protein; however, studies of rotaviruses derived from genetic reassortment between two strains have confirmed that another outer capsid protein, VP3, is in some cases equally important in neutralization. In this study, the genetic relatedness of the genes coding for VP7 of human rotaviruses belonging to serotypes 1 through 4 was examined by hybridization of their denatured double-stranded genomic RNAs to labeled single-stranded mRNA probes derived from human-animal rotavirus reassortants containing only the VP7 gene of their human rotavirus parent. A high degree of homology was demonstrated between the VP7 genes of strain D and other serotype 1 human rotaviruses, strain DS-1 and other serotype 2 human rotaviruses, strain P and other serotype 3 human rotaviruses, and strain ST3 and other serotype 4 human rotaviruses. Hybrid bands could not be demonstrated between the VP7 gene of D, DS-1, P, or ST3 and the corresponding gene of human rotaviruses belonging to a different serotype. RNA specimens extracted from the stools of 15 Venezuelan children hospitalized with rotavirus diarrhea were hybridized to each of the reassortant probes representing the four human serotypes. All five viruses with short RNA patterns showed homology with the DS-1 strain VP7 gene; two of these were previously adapted to tissue culture and shown to be serotype 2 strains by tissue culture neutralization. Of the remaining 10 viruses with long RNA patterns, 2 hybridized only to the D strain VP7 gene, 6 hybridized only to the P strain VP7 gene, and 2 hybridized only to the ST3 strain VP7 gene. Hybridization using single human rotavirus gene substitution reassortants as probes may provide an alternative method for identifying the VP7 serotype of field isolates that would circumvent the need for tissue culture adaptation. Images PMID:3038948

Antibody levels to recombinant VAR2CSA domains vary with Plasmodium falciparum parasitaemia, gestational age, and gravidity, but do not predict pregnancy outcomes.

PubMed

Fried, Michal; Kurtis, Jonathan D; Swihart, Bruce; Morrison, Robert; Pond-Tor, Sunthorn; Barry, Amadou; Sidibe, Youssoufa; Keita, Sekouba; Mahamar, Almahamoudou; Andemel, Naissem; Attaher, Oumar; Dembele, Adama B; Cisse, Kadidia B; Diarra, Bacary S; Kanoute, Moussa B; Narum, David L; Dicko, Alassane; Duffy, Patrick E

2018-03-09

Maternal malaria is a tropical scourge associated with poor pregnancy outcomes. Women become resistant to Plasmodium falciparum pregnancy malaria as they acquire antibodies to the variant surface antigen VAR2CSA, a leading vaccine candidate. Because malaria infection may increase VAR2CSA antibody levels and thereby confound analyses of immune protection, gravidity-dependent changes in antibody levels during and after infection, and the effect of VAR2CSA antibodies on pregnancy outcomes were evaluated. Pregnant women enrolled in a longitudinal cohort study of mother-infant pairs in Ouelessebougou, Mali provided plasma samples at enrollment, gestational week 30-32, and delivery. Antibody levels to VAR2CSA domains were measured using a multiplex bead-based assay. Antibody levels to VAR2CSA were higher in multigravidae than primigravidae. Malaria infection was associated with increased antibody levels to VAR2CSA domains. In primigravidae but not in secundigravidae or multigravidae, antibodies levels sharply declined after an infection. A relationship between any VAR2CSA antibody specificity and protection from adverse pregnancy outcomes was not detected. During malaria infection, primigravidae acquire short-lived antibodies. The lack of an association between VAR2CSA domain antibody reactivity and improved pregnancy outcomes suggests that the recombinant proteins may not present native epitopes targeted by protective antibodies.

VarDict: a novel and versatile variant caller for next-generation sequencing in cancer research

PubMed Central

Lai, Zhongwu; Markovets, Aleksandra; Ahdesmaki, Miika; Chapman, Brad; Hofmann, Oliver; McEwen, Robert; Johnson, Justin; Dougherty, Brian; Barrett, J. Carl; Dry, Jonathan R.

2016-01-01

Abstract Accurate variant calling in next generation sequencing (NGS) is critical to understand cancer genomes better. Here we present VarDict, a novel and versatile variant caller for both DNA- and RNA-sequencing data. VarDict simultaneously calls SNV, MNV, InDels, complex and structural variants, expanding the detected genetic driver landscape of tumors. It performs local realignments on the fly for more accurate allele frequency estimation. VarDict performance scales linearly to sequencing depth, enabling ultra-deep sequencing used to explore tumor evolution or detect tumor DNA circulating in blood. In addition, VarDict performs amplicon aware variant calling for polymerase chain reaction (PCR)-based targeted sequencing often used in diagnostic settings, and is able to detect PCR artifacts. Finally, VarDict also detects differences in somatic and loss of heterozygosity variants between paired samples. VarDict reprocessing of The Cancer Genome Atlas (TCGA) Lung Adenocarcinoma dataset called known driver mutations in KRAS, EGFR, BRAF, PIK3CA and MET in 16% more patients than previously published variant calls. We believe VarDict will greatly facilitate application of NGS in clinical cancer research. PMID:27060149

[Soluble and insoluble dietary fiber in cereals and legumes cultivated in Chile].

PubMed

Pak, N; Ayala, C; Vera, G; Pennacchiotti, I; Araya, H

1990-03-01

Insoluble, soluble and total dietary fiber (DF) were determined in 35 varieties of certified whole seeds (without processing) of cereals (rice, oat, rye, and wheat) and legumes (pea, cowpea, beans, chikpea, lentil and lupine). The enzymatic method of Asp, Johansson and Siljestrom was used, with modifications in relation to time of incubation with alpha amylase, filtration system and volumes of the filtrates. Results were expressed as g/100 g dry weight. Total DF for cereals showed a range from 10.1 (wheat var. Chasqui) to 22.2 (rice var Quella). Rye, var. Tetra Baer and oats var. Pony Baer presented the highest soluble fiber content (3.3 and 3.9, respectively). In legumes, total DF fluctuated between 12.7 (pea, var. yellow) and 36.6 (lupine, var. Multolupa). Bean, var. Pinto INIA and lupine var. Multolupa presented the highest soluble fiber values (5.8 for both). Based on the results of this research work, it might be concluded that great variation exists in regard to the amount of total soluble and insoluble DF in cereals and legumes, a fact which impedes generalization as to its content in each food item.

4D-Var Developement at GMAO

NASA Technical Reports Server (NTRS)

Pelc, Joanna S.; Todling, Ricardo; Akkraoui, Amal El

2014-01-01

The Global Modeling and Assimilation Offce (GMAO) is currently using an IAU-based 3D-Var data assimilation system. GMAO has been experimenting with a 3D-Var-hybrid version of its data assimilation system (DAS) for over a year now, which will soon become operational and it will rapidly progress toward a 4D-EnVar. Concurrently, the machinery to exercise traditional 4DVar is in place and it is desirable to have a comparison of the traditional 4D approach with the other available options, and evaluate their performance in the Goddard Earth Observing System (GEOS) DAS. This work will also explore the possibility for constructing a reduced order model (ROM) to make traditional 4D-Var computationally attractive for increasing model resolutions. Part of the research on ROM will be to search for a suitably acceptable space to carry on the corresponding reduction. This poster illustrates how the IAU-based 4D-Var assimilation compares with our currently used IAU-based 3D-Var.

Isolation of Cryptococcus neoformans var. gattii from Eucalyptus camaldulensis in India.

PubMed Central

Chakrabarti, A; Jatana, M; Kumar, P; Chatha, L; Kaushal, A; Padhye, A A

1997-01-01

Cryptococcus neoformans var. gattii has an ecological association with five Eucalyptus species: E. blakelyi, E. camaldulensis, E. gomphocephala, E. rudis, and E. tereticornis. After human infections due to C. neoformans var. gattii were diagnosed in the states of Punjab, Himachal Pradesh, and Karnataka, India, a study was undertaken to investigate the association of C. neoformans var. gattii with Indian eucalypts, especially in the state of Punjab. A total of 696 specimens collected from E. camaldulensis, E. citriodora and E. tereticornis (hybrid) trees were examined for the presence of C. neoformans var. gattii. Flowers from two trees of E. camaldulensis in the Chak Sarkar forest and one from the village of Periana near the Ferozepur area yielded five isolates of C. neoformans var. gattii. The origin of the trees could be traced to Australia, thus providing evidence that the distribution of E. camaldulensis correlated with the distribution of human cryptococcosis cases caused by C. neoformans var. gattii in northern India. PMID:9399553

Arundina graminifolia var. revoluta (Arethuseae, Orchidaceae) has fern-type rheophyte characteristics in the leaves.

PubMed

Yorifuji, Eri; Ishikawa, Naoko; Okada, Hiroshi; Tsukaya, Hirokazu

2015-03-01

Morphological and molecular variation between Arundina graminifolia var. graminifolia and the dwarf variety, A. graminifolia var. revoluta, was examined to assess the validity of their taxonomic characteristics and genetic background for identification. Morphological analysis in combination with field observations indicated that A. graminifolia var. revoluta is a rheophyte form of A. graminifolia characterized by narrow leaves, whereas the other morphological characteristics described for A. graminifolia var. revoluta, such as smaller flowers and short stems, were not always accompanied by the narrower leaf phenotype. Molecular analysis based on matK sequences indicated that only partial differentiation has occurred between A. graminifolia var. graminifolia and A. graminifolia var. revoluta. Therefore, we should consider the rheophyte form an ecotype rather than a variety. Anatomical observations of the leaves revealed that the rheophyte form of A. graminifolia possessed characteristics of the rheophytes of both ferns and angiosperms, such as narrower palisade tissue cells and thinner spongy tissue cells, as well as fewer cells in the leaf-width direction and fewer mesophyll cell layers.

Empirical analysis on future-cash arbitrage risk with portfolio VaR

NASA Astrophysics Data System (ADS)

Chen, Rongda; Li, Cong; Wang, Weijin; Wang, Ze

2014-03-01

This paper constructs the positive arbitrage position by alternating the spot index with Chinese Exchange Traded Fund (ETF) portfolio and estimating the arbitrage-free interval of futures with the latest trade data. Then, an improved Delta-normal method was used, which replaces the simple linear correlation coefficient with tail dependence correlation coefficient, to measure VaR (Value-at-risk) of the arbitrage position. Analysis of VaR implies that the risk of future-cash arbitrage is less than that of investing completely in either futures or spot market. Then according to the compositional VaR and the marginal VaR, we should increase the futures position and decrease the spot position appropriately to minimize the VaR, which can minimize risk subject to certain revenues.

Development of tailored real-time RT-PCR assays for the detection and differentiation of serotype O, A and Asia-1 foot-and-mouth disease virus lineages circulating in the Middle East.

PubMed

Reid, Scott M; Mioulet, Valerie; Knowles, Nick J; Shirazi, Nazeem; Belsham, Graham J; King, Donald P

2014-10-01

Rapid and accurate diagnosis is essential for effective control of foot-and-mouth disease (FMD). In countries where FMD is endemic, identification of the serotypes of the causative virus strains is important for vaccine selection and tracing the source of outbreaks. In this study, real-time reverse transcription polymerase chain reaction (rRT-PCR) assays using primer/probe sets designed from the VP1 coding region of the virus genomes were developed for the specific detection of serotype O, A and Asia-1 FMD viruses (FMDVs) circulating in the Middle East. These assays were evaluated using representative field samples of serotype O strains belonging exclusively to the PanAsia-2 lineage, serotype A strains of the Iran-05 lineage and serotype Asia-1 viruses from three relevant sub-groups. When RNA extracted from archival and contemporary field strains was tested using one- or two-step rRT-PCR assays, all three primer/probe sets detected the RNA from homotypic viruses and no cross-reactivity was observed with heterotypic viruses. Similar results were obtained using both single- and multiplex assay formats. Using plasmid standards, the minimum detection level of these tests was found to be lower than two copies. The results illustrate the potential of tailored rRT-PCR tools for the detection and categorization of viruses circulating in the Middle East belonging to distinct subgroups of serotypes O, A and Asia-1. These assays can also overcome the problem of serotyping samples which are found positive by the generic rRT-PCR diagnostic assays but negative by virus isolation and antigen-detection ELISA which would otherwise have to be serotyped by nucleotide sequencing. A similar approach could be used to develop serotyping assays for FMDV strains circulating in other regions of the world. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Major tdh(+)Vibrio parahaemolyticus serotype changes temporally in the Bay of Bengal estuary of Bangladesh.

PubMed

Akther, Farhana; Neogi, Sucharit Basu; Chowdhury, Wasimul B; Sadique, Abdus; Islam, Atiqul; Akhter, Marufa Zerin; Johura, Fatema-Tuz; Ohnishi, Makoto; Watanabe, Haruo; Boucher, Yan; Alam, Munirul

2016-07-01

Vibrio parahaemolyticus is responsible for seafood-related gastroenteritis worldwide. In Bangladesh, diarrhea is endemic and diarrheagenic V. parahaemolyticus serotypes occur naturally in the coastal and estuarine aquatic environment. V. parahaemolyticus strains, isolated from estuarine surface water of the Bay of Bengal villages of Bangladesh during 2006-2008, were tested for the presence of virulence and pandemic-marker genes, serodiversity, and phylogenetic relatedness. PCR analysis of V. parahaemolyticus (n=175) showed 53 (30.3%) strains to possess tdh, the major virulence gene encoding thermostable direct hemolysin. Serotyping results revealed the tdh(+)V. parahaemolyticus strains to belong to 10 different serotypes, of which the O8:K21 (30.2%) and O3:K6 (24.5%) were predominantly non-pandemic and pandemic serotypes, respectively; while O5:K30 and O9:KUT were new. The pandemic markers, orf8 and toxRS(variant), were present only in the pandemic serotype O3:K6 (n=13) and its serovariant O4:K68 (n=2). Temporal distribution of the tdh(+) serotypes revealed the O8:K21 to be predominant in 2006 and 2007, while O3:K6 was the predominant tdh(+) serotype in 2008. Pulsed-field gel electrophoresis (PFGE) of SfiI-digested genomic DNA revealed high genetic diversity among the V. parahaemolyticus strains, while dendrogram constructed with the PFGE patterns formed two major clusters separating the tdh(+) O3:K6 and its pandemic serovariants from the tdh(+) non-pandemic (O8:K21) strains, suggesting different lineages for them. The potential health risk related to the prevalent tdh(+) strains, including the observed temporal change of the predominant tdh(+) serotype, from O8:K21 to the pandemic serotype O3:K6 in estuarine surface waters serving as the major source of drinking water suggests the need for routine environmental monitoring to prevent V. parahaemolyticus infection in Bangladesh. Copyright © 2016. Published by Elsevier B.V.

Competitive advantage of a dengue 4 virus when co-infecting the mosquito Aedes aegypti with a dengue 1 virus.

PubMed

Vazeille, Marie; Gaborit, Pascal; Mousson, Laurence; Girod, Romain; Failloux, Anna-Bella

2016-07-08

Dengue viruses (DENV) are comprised in four related serotypes (DENV-1 to 4) and are critically important arboviral pathogens affecting human populations in the tropics. South American countries have seen the reemergence of DENV since the 1970's associated with the progressive re-infestation by the mosquito vector, Aedes aegypti. In French Guiana, DENV is now endemic with the co-circulation of different serotypes resulting in viral epidemics. Between 2009 and 2010, a predominant serotype change occurred from DENV-1 to DENV-4 suggesting a competitive displacement. The aim of the present study was to evaluate the potential role of the mosquito in the selection of the new epidemic serotype. To test this hypothesis of competitive displacement of one serotype by another in the mosquito vector, we performed mono- and co-infections of local Ae. aegypti collected during the inter-epidemic period with both viral autochthonous epidemic serotypes and compared infection, dissemination and transmission rates. We performed oral artificial infections of F1 populations in BSL-3 conditions and analyzed infection, dissemination and transmission rates. When two populations of Ae. aegypti from French Guiana were infected with either serotype, no significant differences in dissemination and transmission were observed between DENV-1 and DENV-4. However, in co-infection experiments, a strong competitive advantage for DENV-4 was seen at the midgut level leading to a much higher dissemination of this serotype. Furthermore only DENV-4 was present in Ae. aegypti saliva and therefore able to be transmitted. In an endemic context, mosquito vectors may be infected by several DENV serotypes. Our results suggest a possible competition between serotypes at the midgut level in co-infected mosquitoes leading to a drastically different transmission potential and, in this case, favoring the competitive displacement of DENV-1 by DENV-4. This phenomenon was observed despite a similar replicative fitness in mono-infections conditions.

Epidemiology of Bluetongue in India.

PubMed

Rao, P P; Hegde, N R; Reddy, Y N; Krishnajyothi, Y; Reddy, Y V; Susmitha, B; Gollapalli, S R; Putty, K; Reddy, G H

2016-04-01

Bluetongue (BT) is an insectborne endemic disease in India. Although infections are observed in domestic and wild ruminants, the clinical disease and mortality are observed only in sheep, especially in the southern states of the country. The difference in disease patterns in different parts of the country could be due to varied climatic conditions, sheep population density and susceptibility of the sheep breeds to BT. Over the five decades after the first report of BT in 1964, most of the known serotypes of bluetongue virus (BTV) have been reported from India either by virus isolation or by detection of serotype-specific antibodies. There have been no structured longitudinal studies to identify the circulating serotypes throughout the country. At least ten serotypes were isolated between 1967 and 2000 (BTV-1-4, 6, 9, 16-18, 23). Since 2001, the All-India Network Programme on Bluetongue and other laboratories have isolated eight different serotypes (BTV-1-3, 9, 10, 12, 16, 21). Genetic analysis of these viruses has revealed that some of them vary substantially from reference viruses, and some show high sequence identity with modified live virus vaccines used in different parts of the world. These observations have highlighted the need to develop diagnostic capabilities, especially as BT outbreaks are still declared based on clinical signs. Although virus isolation and serotyping are the gold standards, rapid methods based on the detection of viral nucleic acid may be more suitable for India. The epidemiological investigations also have implications for vaccine design. Although only a handful serotypes may be involved in causing outbreaks every year, the combination of serotypes may change from year to year. For effective control of BT in India, it may be pertinent to introduce sentinel and vector traps systems for identification of the circulating serotypes and to evaluate herd immunity against different serotypes, so that relevant strains can be included in vaccine formulations. © 2014 Blackwell Verlag GmbH.

Serotype distribution and antimicrobial susceptibility pattern in children≤5years with invasive pneumococcal disease in India - A systematic review.

PubMed

Singh, Jyotsana; Sundaresan, Suba; Manoharan, Anand; Shet, Anita

2017-08-16

Streptococcus pneumoniae is a leading cause of childhood diseases that result in significant morbidity and mortality in India. Commercially licensed and available pneumococcal conjugate vaccines (PCVs) include ten (PCV-10) and 13 (PCV-13) pneumococcal serotypes. Vaccines with other serotype combinations are under development. Reviewing and reporting trends and distribution of pneumococcal serotypes causing invasive pneumococcal disease in India will be useful for policy making as PCV is being introduced into India's universal immunization program. We conducted a systematic literature review of hospital based observational studies (both peer reviewed and gray literature published in English) from India available from January 1990 to December 2016. Studies that documented data on the prevalence of serotype distribution and the antimicrobial resistance pattern of S. pneumoniae in children≤5years of age were included. We screened a total number of 116 studies, of which 109 studies were excluded. Final analysis included seven studies. The most frequent pneumococcal serotypes causing invasive disease among children≤5years were 14, 1, 19F, 6B, 5, 6A, 9V and 23F. Serotype 14 and 19A were represented in most of the geographical regions studied in the reviewed articles. Currently available PCV formulations included 67.3-78.4% of all serotypes contributing to IPD among Indian children≤5years. Pneumococcal resistance to trimethoprim/sulfamethoxazole, erythromycin, penicillin, chloramphenicol, levofloxacin and cefotaxime was seen in 81%, 37%, 10%, 8%, 6% and 4% of all pneumococcal isolates respectively, while vancomycin resistance was not reported. The present review demonstrates that up to 78.4% of reported invasive pneumococcal disease in children≤5years in India are currently caused by serotypes that are included in the available licensed PCVs. However, sentinel surveillance must be continued in representative parts of the country to assess the changing trends in distribution of pneumococcal serotypes and their implication for vaccine selection and rollout in India. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isolation of serotype-specific antibodies against dengue virus non-structural protein 1 using phage display and application in a multiplexed serotyping assay.

PubMed

Lebani, Kebaneilwe; Jones, Martina L; Watterson, Daniel; Ranzoni, Andrea; Traves, Renee J; Young, Paul R; Mahler, Stephen M

2017-01-01

The multidimensional nature of dengue virus (DENV) infections, which can be caused by four distinct serotypes of the virus, complicates the sensitivity of assays designed for the diagnosis of infection. Different viral markers can be optimally detected at different stages of infection. Of particular clinical importance is the early identification of infection, which is pivotal for disease management and the development of blood screening assays. Non-structural protein 1 (NS1) is an early surrogate marker of infection and its detection in serum coincides with detectable viraemia. The aim of this work was to isolate and characterise serotype-specific monoclonal antibodies that bind to NS1 for each of the four DENV serotypes. This was achieved using phage display and a subtractive biopanning strategy to direct the antibody selection towards serotype-specific epitopes. This antibody isolation strategy has advantages over immunisation techniques where it is difficult to avoid antibody responses to cross-reactive, immunodominant epitopes. Serotype specificity to recombinant antigen for each of the antibodies was confirmed by Enzyme Linked Immunosorbent Assay (ELISA) and Surface Plasmon Resonance. Confirmation of binding to native DENV NS1 was achieved using ELISA and immunofluorescence assay on DENV infected Vero cells. No cross-reactivity with Zika or Kunjin viruses was observed. A previously isolated pan-reactive antibody that binds to an immunodominant epitope was able to pair with each of the serotype-specific antibodies in a sandwich ELISA, indicating that the serotype specific antibodies bind to epitopes which are all spatially distinct from the immunodominant epitope. These antibodies were suitable for use in a multiplexed assay for simultaneous detection and serotyping of DENV NS1 in human serum. This work demonstrates that phage display coupled with novel biopanning strategies is a valuable in vitro methodology for isolation of binders that can discern amongst antigens with high homology for diagnostic applicability.

Rapid Engineering of Foot-and-Mouth Disease Vaccine and Challenge Viruses

PubMed Central

Lee, Seo-Yong; Lee, Yeo-Joo; Kim, Rae-Hyung; Park, Jeong-Nam; Park, Min-Eun; Ko, Mi-Kyeong; Choi, Joo-Hyung; Chu, Jia-Qi; Lee, Kwang-Nyeong; Kim, Su-Mi; Tark, Dongseob; Lee, Hyang-Sim; Ko, Young-Joon; Seo, Min-Goo; Park, Jung-Won; Kim, Byounghan; Lee, Myoung-Heon

2017-01-01

ABSTRACT There are seven antigenically distinct serotypes of foot-and-mouth disease virus (FMDV), each of which has intratypic variants. In the present study, we have developed methods to efficiently generate promising vaccines against seven serotypes or subtypes. The capsid-encoding gene (P1) of the vaccine strain O1/Manisa/Turkey/69 was replaced with the amplified or synthetic genes from the O, A, Asia1, C, SAT1, SAT2, and SAT3 serotypes. Viruses of the seven serotype were rescued successfully. Each chimeric FMDV with a replacement of P1 showed serotype-specific antigenicity and varied in terms of pathogenesis in pigs and mice. Vaccination of pigs with an experimental trivalent vaccine containing the inactivated recombinants based on the main serotypes O, A, and Asia1 effectively protected them from virus challenge. This technology could be a potential strategy for a customized vaccine with challenge tools to protect against epizootic disease caused by specific serotypes or subtypes of FMDV. IMPORTANCE Foot-and-mouth disease (FMD) virus (FMDV) causes significant economic losses. For vaccine preparation, the selection of vaccine strains was complicated by high antigenic variation. In the present study, we suggested an effective strategy to rapidly prepare and evaluate mass-produced customized vaccines against epidemic strains. The P1 gene encoding the structural proteins of the well-known vaccine virus was replaced by the synthetic or amplified genes of viruses of seven representative serotypes. These chimeric viruses generally replicated readily in cell culture and had a particle size similar to that of the original vaccine strain. Their antigenicity mirrored that of the original serotype from which their P1 gene was derived. Animal infection experiments revealed that the recombinants varied in terms of pathogenicity. This strategy will be a useful tool for rapidly generating customized FMD vaccines or challenge viruses for all serotypes, especially for FMD-free countries, which have prohibited the import of FMDVs. PMID:28566375

Characterization of Foot-And-Mouth Disease Viruses (FMDVs) from Ugandan Cattle Outbreaks during 2012-2013: Evidence for Circulation of Multiple Serotypes

PubMed Central

Namatovu, Alice; Tjørnehøj, Kirsten; Belsham, Graham J.; Dhikusooka, Moses T.; Wekesa, Sabenzia N.; Muwanika, Vincent B.; Siegismund, Hans R.; Ayebazibwe, Chrisostom

2015-01-01

To investigate the foot-and-mouth disease virus (FMDV) serotypes circulating in Uganda’s cattle population, both serological and virological analyses of samples from outbreaks that occurred during 2012–2013 were performed. Altogether, 79 sera and 60 oropharyngeal fluid (OP)/tissue/oral swab samples were collected from herds with reported FMD outbreaks in seven different Ugandan districts. Overall, 61/79 (77%) of the cattle sera were positive for antibodies against FMDV by PrioCHECK FMDV NS ELISA and solid phase blocking ELISA detected titres ≥ 80 for serotypes O, SAT 1, SAT 2 and SAT 3 in 41, 45, 30 and 45 of these 61 seropositive samples, respectively. Virus neutralisation tests detected the highest levels of neutralising antibodies (titres ≥ 45) against serotype O in the herds from Kween and Rakai districts, against SAT 1 in the herd from Nwoya district and against SAT 2 in the herds from Kiruhura, Isingiro and Ntungamo districts. The isolation of a SAT 2 FMDV from Isingiro was consistent with the detection of high levels of neutralising antibodies against SAT 2; sequencing (for the VP1 coding region) indicated that this virus belonged to lineage I within this serotype, like the currently used vaccine strain. From the Wakiso district 11 tissue/swab samples were collected; serotype A FMDV, genotype Africa (G-I), was isolated from the epithelial samples. This study shows that within a period of less than one year, FMD outbreaks in Uganda were caused by four different serotypes namely O, A, SAT 1 and SAT 2. Therefore, to enhance the control of FMD in Uganda, there is need for efficient and timely determination of outbreak virus strains/serotypes and vaccine matching. The value of incorporating serotype A antigen into the imported vaccines along with the current serotype O, SAT 1 and SAT 2 strains should be considered. PMID:25664876

Rapid Engineering of Foot-and-Mouth Disease Vaccine and Challenge Viruses.

PubMed

Lee, Seo-Yong; Lee, Yeo-Joo; Kim, Rae-Hyung; Park, Jeong-Nam; Park, Min-Eun; Ko, Mi-Kyeong; Choi, Joo-Hyung; Chu, Jia-Qi; Lee, Kwang-Nyeong; Kim, Su-Mi; Tark, Dongseob; Lee, Hyang-Sim; Ko, Young-Joon; Seo, Min-Goo; Park, Jung-Won; Kim, Byounghan; Lee, Myoung-Heon; Lee, Jong-Soo; Park, Jong-Hyeon

2017-08-15

There are seven antigenically distinct serotypes of foot-and-mouth disease virus (FMDV), each of which has intratypic variants. In the present study, we have developed methods to efficiently generate promising vaccines against seven serotypes or subtypes. The capsid-encoding gene (P1) of the vaccine strain O1/Manisa/Turkey/69 was replaced with the amplified or synthetic genes from the O, A, Asia1, C, SAT1, SAT2, and SAT3 serotypes. Viruses of the seven serotype were rescued successfully. Each chimeric FMDV with a replacement of P1 showed serotype-specific antigenicity and varied in terms of pathogenesis in pigs and mice. Vaccination of pigs with an experimental trivalent vaccine containing the inactivated recombinants based on the main serotypes O, A, and Asia1 effectively protected them from virus challenge. This technology could be a potential strategy for a customized vaccine with challenge tools to protect against epizootic disease caused by specific serotypes or subtypes of FMDV. IMPORTANCE Foot-and-mouth disease (FMD) virus (FMDV) causes significant economic losses. For vaccine preparation, the selection of vaccine strains was complicated by high antigenic variation. In the present study, we suggested an effective strategy to rapidly prepare and evaluate mass-produced customized vaccines against epidemic strains. The P1 gene encoding the structural proteins of the well-known vaccine virus was replaced by the synthetic or amplified genes of viruses of seven representative serotypes. These chimeric viruses generally replicated readily in cell culture and had a particle size similar to that of the original vaccine strain. Their antigenicity mirrored that of the original serotype from which their P1 gene was derived. Animal infection experiments revealed that the recombinants varied in terms of pathogenicity. This strategy will be a useful tool for rapidly generating customized FMD vaccines or challenge viruses for all serotypes, especially for FMD-free countries, which have prohibited the import of FMDVs. Copyright © 2017 Lee et al.

Biofilm formation by Shiga toxin-producing Escherichia coli O157:H7 and Non-O157 strains and their tolerance to sanitizers commonly used in the food processing environment.

PubMed

Wang, Rong; Bono, James L; Kalchayanand, Norasak; Shackelford, Steven; Harhay, Dayna M

2012-08-01

Shiga toxin-producing Escherichia coli (STEC) strains are important foodborne pathogens. Among these, E. coli O157:H7 is the most frequently isolated STEC serotype responsible for foodborne diseases. However, the non-O157 serotypes have been associated with serious outbreaks and sporadic diseases as well. It has been shown that various STEC serotypes are capable of forming biofilms on different food or food contact surfaces that, when detached, may lead to cross-contamination. Bacterial cells at biofilm stage also are more tolerant to sanitizers compared with their planktonic counterparts, which makes STEC biofilms a serious food safety concern. In the present study, we evaluated the potency of biofilm formation by a variety of STEC strains from serotypes O157:H7, O26:H11, and O111:H8; we also compared biofilm tolerance with two types of common sanitizers, a quaternary ammonium chloride-based sanitizer and chlorine. Our results demonstrated that biofilm formation by various STEC serotypes on a polystyrene surface was highly strain-dependent, whereas the two non-O157 serotypes showed a higher potency of pellicle formation at air-liquid interfaces on a glass surface compared with serotype O157:H7. Significant reductions of viable biofilm cells were achieved with sanitizer treatments. STEC biofilm tolerance to sanitization was strain-dependent regardless of the serotypes. Curli expression appeared to play a critical role in STEC biofilm formation and tolerance to sanitizers. Our data indicated that multiple factors, including bacterial serotype and strain, surface materials, and other environmental conditions, could significantly affect STEC biofilm formation. The high potential for biofilm formation by various STEC serotypes, especially the strong potency of pellicle formation by the curli-positive non-O157 strains with high sanitization tolerance, might contribute to bacterial colonization on food contact surfaces, which may result in downstream product contamination.

MLST and Whole-Genome-Based Population Analysis of Cryptococcus gattii VGIII Links Clinical, Veterinary and Environmental Strains, and Reveals Divergent Serotype Specific Sub-populations and Distant Ancestors

PubMed Central

Firacative, Carolina; Roe, Chandler C.; Malik, Richard; Ferreira-Paim, Kennio; Escandón, Patricia; Sykes, Jane E.; Castañón-Olivares, Laura Rocío; Contreras-Peres, Cudberto; Samayoa, Blanca; Sorrell, Tania C.; Castañeda, Elizabeth; Lockhart, Shawn R.; Engelthaler, David M.; Meyer, Wieland

2016-01-01

The emerging pathogen Cryptococcus gattii causes life-threatening disease in immunocompetent and immunocompromised hosts. Of the four major molecular types (VGI-VGIV), the molecular type VGIII has recently emerged as cause of disease in otherwise healthy individuals, prompting a need to investigate its population genetic structure to understand if there are potential genotype-dependent characteristics in its epidemiology, environmental niche(s), host range and clinical features of disease. Multilocus sequence typing (MLST) of 122 clinical, environmental and veterinary C. gattii VGIII isolates from Australia, Colombia, Guatemala, Mexico, New Zealand, Paraguay, USA and Venezuela, and whole genome sequencing (WGS) of 60 isolates representing all established MLST types identified four divergent sub-populations. The majority of the isolates belong to two main clades, corresponding either to serotype B or C, indicating an ongoing species evolution. Both major clades included clinical, environmental and veterinary isolates. The C. gattii VGIII population was genetically highly diverse, with minor differences between countries, isolation source, serotype and mating type. Little to no recombination was found between the two major groups, serotype B and C, at the whole and mitochondrial genome level. C. gattii VGIII is widespread in the Americas, with sporadic cases occurring elsewhere, WGS revealed Mexico and USA as a likely origin of the serotype B VGIII population and Colombia as a possible origin of the serotype C VGIII population. Serotype B isolates are more virulent than serotype C isolates in a murine model of infection, causing predominantly pulmonary cryptococcosis. No specific link between genotype and virulence was observed. Antifungal susceptibility testing against six antifungal drugs revealed that serotype B isolates are more susceptible to azoles than serotype C isolates, highlighting the importance of strain typing to guide effective treatment to improve the disease outcome. PMID:27494185

Bluetongue Viruses Based on Modified-Live Vaccine Serotype 6 with Exchanged Outer Shell Proteins Confer Full Protection in Sheep against Virulent BTV8

PubMed Central

van Gennip, René G. P.; van de Water, Sandra G. P.; Maris-Veldhuis, Mieke; van Rijn, Piet A.

2012-01-01

Since 1998, Bluetongue virus (BTV)-serotypes 1, 2, 4, 9, and 16 have invaded European countries around the Mediterranean Basin. In 2006, a huge BT outbreak started after incursion of BTV serotype 8 (BTV8) in North-Western Europe. IN 2008, BTV6 and BTV11 were reported in the Netherlands and Germany, and in Belgium, respectively. In addition, Toggenburg orbivirus (TOV) was detected in 2008 in Swiss goats, which was recognized as a new serotype of BTV (BTV25). The (re-)emergency of BTV serotypes needs a rapid response to supply effective vaccines. Reverse genetics has been developed for BTV1 and more recently also for BTV6. This latter strain, BTV6/net08, is closely related to live-attenuated vaccine for serotype 6 as determined by full genome sequencing. Here, we used this strain as backbone and exchanged segment 2 and 6, respectively Seg-2 (VP2) and Seg-6 (VP5), for those of BTV serotype 1 and 8 using reverse genetics. These so-called ‘serotyped’ vaccine viruses, as mono-serotype and multi-serotype vaccine, were compared for their protective capacity in sheep. In general, all vaccinated animals developed a neutralizing antibody response against their respective serotype. After challenge at three weeks post vaccination with cell-passaged, virulent BTV8/net07 (BTV8/net07/e1/bhkp3) the vaccinated animals showed nearly no clinical reaction. Even more, challenge virus could not be detected, and seroconversion or boostering after challenge was negligible. These data demonstrate that all sheep were protected from a challenge with BTV8/net07, since sheep of the control group showed viremia, seroconversion and clinical signs that are specific for Bluetongue. The high level of cross-protection is discussed. PMID:23049753

Longitudinal survey of the distribution of various serotypes of Streptococcus mutans in infants.

PubMed

Masuda, N; Tsutsumi, N; Sobue, S; Hamada, S

1979-10-01

The establishment of various serotypes of Streptococcus mutans was studied serologically in plaque samples collected from label surfaces of upper primary incisors of 22 infants (starting age, 5 to 13 months) over a period fo 30 months. Clinical examinations were also performed. No clear-cut association between the initiation of dental caries and previous detection of S. mutans was noted. However, all 12 of the infants with caries had S. mutans isolated at some time during the course of this study. The most common serotype isolated at the initial establishment of S. mutans on the tooth surfaces was serotype c, whereas types d, e, and g became established in a few cases. During the test period, changes in the distribution of serotypes of S. mutans were observed in some cases. The initiation of carious lesions could be found in a few cases even when S. mutans comprised about 1% or less of the total streptococcal count of the specimen from the tooth surfaces. Serotype d/g strains tended to develop carious lesions on smooth surfaces, although serotype c was isolated from almost all individuals who developed caries.

Probability of identifying different salmonella serotypes in poultry samples

USDA-ARS?s Scientific Manuscript database

Recent work has called attention to the unequal competitive abilities of different Salmonella serotypes in standard broth culture and plating media. Such serotypes include Enteritidis and Typhimurium that are specifically targeted in some regulatory and certification programs because they cause a l...

Salmonella enterica Infections in the United States and Assessment of Coefficients of Variation: A Novel Approach to Identify Epidemiologic Characteristics of Individual Serotypes, 1996–2011

PubMed Central

Boore, Amy L.; Hoekstra, R. Michael; Iwamoto, Martha; Fields, Patricia I.; Bishop, Richard D.; Swerdlow, David L.

2015-01-01

Background Despite control efforts, salmonellosis continues to cause an estimated 1.2 million infections in the United States (US) annually. We describe the incidence of salmonellosis in the US and introduce a novel approach to examine the epidemiologic similarities and differences of individual serotypes. Methods Cases of salmonellosis in humans reported to the laboratory-based National Salmonella Surveillance System during 1996–2011 from US states were included. Coefficients of variation were used to describe distribution of incidence rates of common Salmonella serotypes by geographic region, age group and sex of patient, and month of sample isolation. Results During 1996–2011, more than 600,000 Salmonella isolates from humans were reported, with an average annual incidence of 13.1 cases/100,000 persons. The annual reported rate of Salmonella infections did not decrease during the study period. The top five most commonly reported serotypes, Typhimurium, Enteritidis, Newport, Heidelberg, and Javiana, accounted for 62% of fully serotyped isolates. Coefficients of variation showed the most geographically concentrated serotypes were often clustered in Gulf Coast states and were also more frequently found to be increasing in incidence. Serotypes clustered in particular months, age groups, and sex were also identified and described. Conclusions Although overall incidence rates of Salmonella did not change over time, trends and epidemiological factors differed remarkably by serotype. A better understanding of Salmonella, facilitated by this comprehensive description of overall trends and unique characteristics of individual serotypes, will assist in responding to this disease and in planning and implementing prevention activities. PMID:26701276

Clinical significance of serotype V among infants with invasive group B streptococcal infections in South Korea.

PubMed

Yoon, In Ae; Jo, Dae Sun; Cho, Eun Young; Choi, Eun Hwa; Lee, Hoan Jong; Lee, Hyunju

2015-09-01

Group B Streptococcus (GBS) strains are classified by the polysaccharide capsule, which is an important virulence factor and stimulator of antibody-associated immunity. As GBS infections in neonates may be life-threatening, GBS screening and intrapartum antibiotic prophylaxis have been implemented for prevention. In Korea, there are few reports on the GBS serotype distribution and antibiotic resistance patterns because GBS screening and intrapartum prophylaxis are not done routinely. The serotype distribution and antibiotic resistance of GBS in infants in Korea with invasive bacterial infections were examined for the 19-year period 1995-2013. Isolates obtained previously from hospitals located in three different regions were analyzed for capsular serotype by PCR and sequencing and for antimicrobial susceptibility. Among 56 isolates serotyped, the most common serotypes were III (44.6%) and V (28.6%), followed by Ia (14.3%), Ib (10.7%), and VI (1.8%). No penicillin-resistant strains were detected, however 51.8% of the strains had resistance to erythromycin and 55.4% showed clindamycin resistance. Resistance was highest (93.8%) to both erythromycin and clindamycin for serotype V; all 15 isolates resistant to erythromycin were cMLSB phenotype and had a high level of resistance to both erythromycin and clindamycin with MIC levels >256μg/ml, and all but one were positive for ermB. In this study in Korea, serotype V was identified in a relatively large proportion of GBS isolates and this serotype showed a high level of resistance to erythromycin and clindamycin in a statistically significant majority. Continuous monitoring of changes in clinical disease and molecular characteristics is important for the treatment and prevention of invasive GBS disease in infants. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Vibrio parahaemolyticus Strains of Pandemic Serotypes Identified from Clinical and Environmental Samples from Jiangsu, China

PubMed Central

Li, Jingjiao; Xue, Feng; Yang, Zhenquan; Zhang, Xiaoping; Zeng, Dexin; Chao, Guoxiang; Jiang, Yuan; Li, Baoguang

2016-01-01

Vibrio parahaemolyticus has emerged as a major foodborne pathogen in China, Japan, Thailand, and other Asian countries. In this study, 72 strains of V. parahaemolyticus were isolated from clinical and environmental samples between 2006 and 2014 in Jiangsu, China. The serotypes and six virulence genes including thermostable direct hemolysin (TDR) and TDR-related hemolysin (TRH) genes were assessed among the isolates. Twenty five serotypes were identified and O3:K6 was one of the dominant serotypes. The genetic diversity was assessed by multilocus sequence typing (MLST) analysis, and 48 sequence types (STs) were found, suggesting this V. parahaemolyticus group is widely dispersed and undergoing rapid evolution. A total of 25 strains of pandemic serotypes such as O3:K6, O5:K17, and O1:KUT were identified. It is worth noting that the pandemic serotypes were not exclusively identified from clinical samples, rather, nine strains were also isolated from environmental samples; and some of these strains harbored several virulence genes, which may render those strains pathogenicity potential. Therefore, the emergence of these “environmental” pandemic V. parahaemolyticus strains may poses a new threat to the public health in China. Furthermore, six novel serotypes and 34 novel STs were identified among the 72 isolates, indicating that V. parahaemolyticus were widely distributed and fast evolving in the environment in Jiangsu, China. The findings of this study provide new insight into the phylogenic relationship between V. parahaemolyticus strains of pandemic serotypes from clinical and environmental sources and enhance the MLST database; and our proposed possible O- and K- antigen evolving paths of V. parahaemolyticus may help understand how the serotypes of this dispersed bacterial population evolve. PMID:27303379

Group B Streptococci serotype distribution in pregnant women in Ghana: assessment of potential coverage through future vaccines.

PubMed

Vinnemeier, C D; Brust, P; Owusu-Dabo, E; Sarpong, N; Sarfo, E Y; Bio, Y; Rolling, T; Dekker, D; Adu-Sarkodie, Y; Eberhardt, K A; May, J; Cramer, J P

2015-11-01

Group B streptococcal (GBS) colonization of pregnant women can lead to subsequent infection of the new-born and potentially fatal invasive disease. Data on GBS colonization prevalence and serotype distribution from Africa are scarce, although GBS-related infections are estimated to contribute substantially to infant mortality. In recent years, GBS vaccine candidates provided promising results in phase I and II clinical trials. We aimed to assess the prevalence and serotype distribution of GBS in Ghana since this knowledge is a prerequisite for future evaluation of vaccine trials. This double-centre study was conducted in one rural and one urban hospital in central Ghana, West Africa. Women in late pregnancy (≥35 weeks of gestation) attending the antenatal care clinic (ANC) provided recto-vaginal swabs for GBS testing. GBS isolates were analysed for serotype and antibiotic susceptibility. GBS-positive women were treated with intrapartum antibiotic prophylaxis (IAP) according to current guidelines of the Center for Disease Control and Prevention (CDC). In total, 519 women were recruited at both study sites, recto-vaginal swabs were taken from 509. The overall prevalence of GBS was 19.1% (18.1% in rural Pramso and 23.1% in urban Kumasi, restrospectively). Capsular polysaccharide serotype (CPS) Ia accounted for the most frequent serotype beyond all isolates (28.1%), followed by serotype V (27.1%) and III (21.9%). No resistance to Penicillin was found, resistances to second line antibiotics clindamycin and erythromycin were 3.1% and 1%, respectively. Group B Streptococcus serotype distribution in Ghana is similar to that worldwide, but variations in prevalence of certain serotypes between the urban and rural study site were high. Antibiotic resistance of GBS strains was surprisingly low in this study. © 2015 John Wiley & Sons Ltd.

The Effect of Formulation on Spray Dried Sabin Inactivated Polio Vaccine.

PubMed

Kanojia, Gaurav; Ten Have, Rimko; Brugmans, Debbie; Soema, Peter C; Frijlink, Henderik W; Amorij, Jean-Pierre; Kersten, Gideon

2018-05-19

The objective of this study was to develop a stable spray dried formulation, containing the three serotypes of Sabin inactivated polio vaccine (sIPV), aiming for minimal loss of native conformation (D-antigen) during drying and subsequent storage. The influence of atomization and drying stress during spray drying on trivalent sIPV was investigated. This was followed by excipient screening, in which monovalent sIPV was formulated and spray dried. Excipient combinations and concentrations were tailored to maximize both the antigen recovery of respective sIPV serotypes after spray drying and storage (T= 40°C and t= 7 days). Furthermore, a fractional factorial design was developed around the most promising formulations to elucidate the contribution of each excipient in stabilizing D-antigen during drying. Serotype 1 and 2 could be dried with 98 % and 97 % recovery, respectively. When subsequently stored at 40°C for 7 days, the D-antigenicity of serotype 1 was fully retained. For serotype 2 the D-antigenicity dropped to 71 %. Serotype 3 was more challenging to stabilize and a recovery of 56 % was attained after drying, followed by a further loss of 37 % after storage at 40°C for 7 days. Further studies using a design of experiments approach demonstrated that trehalose/monosodium glutamate and maltodextrin/arginine combinations were crucial for stabilizing serotype 1 and 2, respectively. For sIPV serotype 3, the best formulation contained Medium199, glutathione and maltodextrin. For the trivalent vaccine it is therefore probably necessary to spray dry the different serotypes separately and mix the dry powders afterwards to obtain the trivalent vaccine. Copyright © 2018. Published by Elsevier B.V.

Genetic and structural elucidation of capsular polysaccharides from Streptococcus pneumoniae serotype 23A and 23B, and comparison to serotype 23F.

PubMed

Ravenscroft, Neil; Omar, Aneesa; Hlozek, Jason; Edmonds-Smith, Cesarina; Follador, Rainer; Serventi, Fabio; Lipowsky, Gerd; Kuttel, Michelle M; Cescutti, Paola; Faridmoayer, Amirreza

2017-10-10

Streptococcus pneumoniae is a globally important encapsulated human pathogen with approximately 100 different serotypes recognized. Serogroup 23 consists of serotype 23F, present in licensed vaccines, and emerging serotypes 23A and 23B. Here, we report the previously unknown structures of the pneumococcal capsular polysaccharides serotype 23A and 23B determined using genetic analysis, NMR spectroscopy, composition and linkage analysis and Smith degradation (of polysaccharide 23A). The structure of the serotype 23A capsular polysaccharide is: →4)-β-D-Glcp-(1→3)-[[α-L-Rhap-(1→2)]-[Gro-(2→P→3)]-β-D-Galp-(1→4)]-β-L-Rhap-(1→. This structure differs from polysaccharide 23F as it features a disaccharide backbone and the di-substituted β-Gal is linked to β-Rha as a side chain. This is due to the different polymerization position catalysed by the unusually divergent repeat unit polymerase Wzy in the 23A cps biosynthesis locus. Steric crowding in 23A, confirmed by molecular models, causes the NMR signal for H-1 of the di-substituted 2,3-β-Gal to resonate in the α-anomeric region. The structure of the serotype 23B capsular polysaccharide is the same as 23F, but without the terminal α-Rha: →4)-β-D-Glcp-(1→4)-[Gro-(2→P→3)]-β-D-Galp-(1→4)-β-L-Rhap-(1→. The immunodominant terminal α-Rha of 23F is more sterically crowded in 23A and absent in 23B. This may explain the reported typing cross reactions for serotype 23F: slight with 23A and none with 23B. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dynamics of Colonization of Streptococcus pneumoniae Strains in Healthy Peruvian Children

PubMed Central

Nelson, Kristin N; Grijalva, Carlos G; Chochua, Sopio; Hawkins, Paulina A; Gil, Ana I; Lanata, Claudio F; Griffin, Marie R; Edwards, Kathryn M; Klugman, Keith P; Vidal, Jorge E

2018-01-01

Abstract Background Although asymptomatic carriage of Streptococcus pneumoniae (Spn) is common, acquisition of the bacteria is the first step in disease pathogenesis. We examined the effect of introduction of the 7-valent pneumococcal vaccine on Spn carriage patterns in a cohort of Peruvian children. Methods We used data from a prospective cohort study that collected monthly nasopharyngeal samples from children under 3 years of age. Spn isolates were serotyped using Quellung reactions, and bacterial density was determined by quantitative polymerase chain reaction. Changes in Spn carriage patterns, including the rate of carriage and number and density of serotypes carried over time, were evaluated before (2009) and after widespread vaccination with PCV7 (2011). Using all pneumococcal detections from each child and year, we identified serotypes that were present both at first and last detection as “persisters” and serotypes that replaced a different earlier type and were detected last as “recolonizers.” Results Ninety-two percent (467/506) of children in 2009 and 89% (451/509) in 2011 carried Spn at least once. In 2009 and 2011, rates of carriage were 9.03 and 9.04 Spn detections per person-year, respectively. In 2009, 23F, a serotype included in PCV7, was the only type identified as a persister and 6A, 15B, and 19A were identified as recolonizer serotypes. In 2011, 6B and 7C were persister serotypes and 13 was a frequent recolonizer serotype. Conclusions Overall Spn carriage among children under 3 in Peru was similar before and after introduction of PCV7; however, serotype-specific rates and longitudinal carriage patterns have shifted. PMID:29588913

Streptococcus suis Bacterin and Subunit Vaccine Immunogenicities and Protective Efficacies against Serotypes 2 and 9▿†

PubMed Central

Baums, Christoph Georg; Kock, Christoph; Beineke, Andreas; Bennecke, Katharina; Goethe, Ralph; Schröder, Charlotte; Waldmann, Karl-Heinz; Valentin-Weigand, Peter

2009-01-01

Streptococcus suis causes numerous diseases in pigs, most importantly, meningitis, arthritis, septicemia, and bronchopneumonia. One of the major problems in modern swine production is the lack of a vaccine protecting against more than one S. suis serotype. The objective of this study was to determine the protective efficacy of a serotype 2 murein-associated protein (MAP) fraction subunit vaccine in comparison to that of a bacterin against experimental challenge with serotype 2 (containing muramidase-released protein [MRP], extracellular factor, and suilysin [SLY]) and serotype 9 (containing MRP variant MRP* and SLY) strains. MAP was shown to include different surface-associated proteins, such as the MRP and surface antigen one (SAO) expressed by both pathotypes used for challenge. The results of this study demonstrated that the serotype 2 bacterin induced protective immunity against homologous challenge. In contrast, the protective efficacy of the MAP subunit vaccine was low, though MAP immunization resulted in high serum immunoglobulin G2 titers against MRP and SAO. Importantly, immunization with bacterin but not with MAP induced opsonizing antibody titers against the serotype 2 strain, and these antibody titers were found to correlate with protection. However, after absorption with a nonencapsulated isogenic mutant, the sera from bacterin-immunized piglets failed to facilitate neutrophil killing, indicating that antibodies directed against capsule may not have been essential for opsonophagocytosis. Furthermore, induction of opsonizing antibodies against serotype 9 was not detectable in the group receiving bacterin or in the group receiving the MAP vaccine. In agreement, protection against the heterologous serotype 9 strain was low in both groups. Thus, identification of an antigen protecting against these two important S. suis pathotypes remains an important goal of future studies. PMID:19109449

Two complex, adenovirus-based vaccines that together induce immune responses to all four dengue virus serotypes.

PubMed

Holman, David H; Wang, Danher; Raviprakash, Kanakatte; Raja, Nicholas U; Luo, Min; Zhang, Jianghui; Porter, Kevin R; Dong, John Y

2007-02-01

Dengue virus infections can cause hemorrhagic fever, shock, encephalitis, and even death. Worldwide, approximately 2.5 billion people live in dengue-infested regions with about 100 million new cases each year, although many of these infections are believed to be silent. There are four antigenically distinct serotypes of dengue virus; thus, immunity from one serotype will not cross-protect from infection with the other three. The difficulties that hamper vaccine development include requirements of the natural conformation of the envelope glycoprotein to induce neutralizing immune responses and the necessity of presenting antigens of all four serotypes. Currently, the only way to meet these requirements is to use a mixture of four serotypes of live attenuated dengue viruses, but safety remains a major problem. In this study, we have developed the basis for a tetravalent dengue vaccine using a novel complex adenovirus platform that is capable of expressing multiple antigens de novo. This dengue vaccine is constructed as a pair of vectors that each expresses the premembrane and envelope genes of two different dengue virus serotypes. Upon vaccination, the vaccine expressed high levels of the dengue virus antigens in cells to mimic a natural infection and induced both humoral and cellular immune responses against multiple serotypes of dengue virus in an animal model. Further analyses show the humoral responses were indeed neutralizing against all four serotypes. Our studies demonstrate the concept of mimicking infections to induce immune responses by synthesizing dengue virus membrane antigens de novo and the feasibility of developing an effective tetravalent dengue vaccine by vector-mediated expression of glycoproteins of the four serotypes.

Emergence of antibiotic-resistant non-vaccine serotype pneumococci in nasopharyngeal carriage in children after the use of extended-valency pneumococcal conjugate vaccines in Korea.

PubMed

Choe, Young June; Lee, Hoan Jong; Lee, Hyunju; Oh, Chi Eun; Cho, Eun Young; Choi, Jae Hong; Kang, Hyun Mi; Yoon, In Ae; Jung, Hyun Joo; Choi, Eun Hwa

2016-09-14

This study was performed to assess the serotype distribution and antibiotic nonsusceptibility of pneumococcal carriage isolates from children in Korea following the introduction of extended-valency pneumococcal conjugate vaccines (PCVs). From April to June 2014, nasopharyngeal swabs were collected from children who were attending daycare centers in Korea. The collection was conducted in accordance with the World Health Organization Pneumococcal Carriage Working Group standards. Isolates were identified based on colony morphology, the presence of alpha-hemolysis, and inhibition by optochin test. Serotype was determined by Quellung reaction and sequencing analysis (for serogroup 6). The E-test was performed to determine antibiotic susceptibility. A total of 267 pneumococcal isolates were collected from 734 children. Non-PCV13 serotypes accounted for 88.3% and 23A (12.6%), 15B (10.4%), and 15C (9.5%) were most common. Younger age was associated with higher carriage (65.6% vs. 31.2%, P<0.001), while completion of PCV vaccination was associated with lower carriage caused by PCV13 serotypes (7.4% vs. 20.8%, P=0.007). Overall, nonsusceptibility rates were 86.0% to penicillin and 90.5% to erythromycin, with a multidrug resistance rate of 81.5%. Among penicillin-nonsusceptible isolates, those caused by PCV13 serotypes were 11% and non-PCV13 serotypes were 89%. Frequent non-PCV13 serotypes (23A, 15B, and 15C) were all nonsusceptible to both penicillin and erythromycin except one. High rates of carriage caused by non-PCV13 serotypes such as 23A, 15B, and 15C that show nonsusceptibilities to penicillin and erythromycin were noted following the introduction of extended-valency PCVs in Korea. Copyright © 2016 Elsevier Ltd. All rights reserved.

A proposed harmonized LPS molecular-subtyping scheme for Cronobacter species.

PubMed

Yan, Qiongqiong; Jarvis, Karen G; Chase, Hannah R; Hébert, Karine; Trach, Larisa H; Lee, Chloe; Sadowski, Jennifer; Lee, Boram; Hwang, Seongeun; Sathyamoorthy, Venugopal; Mullane, Niall; Pava-Ripoll, Monica; Iversen, Carol; Pagotto, Franco; Fanning, Séamus; Tall, Ben D

2015-09-01

Cronobacter are opportunistic pathogens, which cause infections in all age groups. To aid the characterization of Cronobacter in foods and environments a harmonized LPS identification scheme for molecular serotyping is needed. To this end, we studied 409 Cronobacter isolates representing the seven Cronobacter species using two previously reported molecular serotyping schemes, described here as Mullane-Jarvis (M-J) and Sun schemes. PCR analysis revealed many overlapping results that were obtained when independently applying the two serotyping schemes. There were complete agreements between the two PCR schemes for Cronobacter sakazakii (Csak) O:1, Csak O:3, and Csak O:7 serotypes. However, only thirty-five of 41 Csak O:4 strains, identified using the M-J scheme, were PCR-positive with the Sun scheme primers. Also the Sun scheme Csak O:5 primers failed to identify this serotype in any of the C. sakazakii strains tested, but did recognize seven Cronobacter turicensis strains, which were identified as Ctur O:3 using the M-J scheme. Similarly, the Sun scheme Csak O:6 primers recognized 30 Cronobacter malonaticus O:2 strains identified with the M-J scheme, but failed to identify this serotype in any C. sakazakii strain investigated. In this report, these findings are summarized and a harmonized molecular-serotyping scheme is proposed which is predicated on the correct identification of Cronobacter species, prior to serotype determination. In summary, fourteen serotypes were identified using the combined protocol, which consists of Csak O:1-O:4, and Csak O:7; Cmal O:1-O:2; Cdub O:1-O:2, Cmuy O:1-O:2, Cuni O:1, as well as Ctur O:1 and Ctur O:3. Published by Elsevier Ltd.

Trigger factor of Streptococcus suis is involved in stress tolerance and virulence.

PubMed

Wu, Tao; Zhao, Zhanqin; Zhang, Lin; Ma, Hongwei; Lu, Ka; Ren, Wen; Liu, Zhengya; Chang, Haitao; Bei, Weicheng; Qiu, Yinsheng; Chen, Huanchun

2011-01-01

Streptococcus suis serotype 2 is an important zoonotic pathogen that causes serious diseases such as meningitis, septicemia, endocarditis, arthritis and septic shock in pigs and humans. Little is known about the regulation of virulence gene expression in S. suis serotype 2. In this study, we cloned and deleted the entire tig gene from the chromosome of S. suis serotype 2 SC21 strain, and constructed a mutant strain (Δtig) and a complementation strain (CΔtig). The results demonstrated that the tig gene, encoding trigger factor from S. suis serotype 2 SC21, affects the stress tolerance and the expression of a few virulence genes of S. suis serotype 2. Deletion of the tig gene of S. suis serotype 2 resulted in mutant strain, ΔTig, which exhibited a significant decrease in adherence to cell line HEp-2, and lacked hemolytic activity. Tig deficiency diminishes stresses tolerance of S. suis serotype 2 such as survive thermal, oxidative and acid stresses. Quantification of expression levels of known S. suis serotype 2 SC21 virulence genes by real-time polymerase chain reaction in vitro revealed that trigger factor influences the expression of epf, cps, adh, rpob, fbps, hyl, sly, mrp and hrcA virulence-associated genes. ΔTig was shown to be attenuated in a LD50 assay and bacteriology, indicating that trigger factor plays an important part in the pathogenesis and stress tolerance of. S. suis serotype 2 infection. Mutant ΔTig was 100% defective in virulence in CD1 mice at up to 107 CFU, and provided 100% protection when challenged with 107 CFU of the SC21 strain. Copyright © 2010. Published by Elsevier India Pvt Ltd.

A var gene promoter implicated in severe malaria nucleates silencing and is regulated by 3’ untranslated region and intronic cis-elements

PubMed Central

Muhle, Rebecca A.; Adjalley, Sophie; Falkard, Brie; Nkrumah, Louis J.; Muhle, Michael E.; Fidock, David A.

2009-01-01

Questions surround the mechanism of mutually exclusive expression by which Plasmodium falciparum mediates activation and silencing of var genes. These encode PfEMP1 proteins, which function as cytoadherent and immunomodulatory molecules at the surface of parasitized erythrocytes. Current evidence suggests that promoter silencing by var introns might play a key role in var gene regulation. To evaluate the impact of cis-acting regulatory regions on var silencing, we generated P. falciparum lines in which luciferase was placed under the control of an UpsA var promoter. By utilizing the Bxb1 integrase system, these reporter cassettes were targeted to a genomic region that was not in apposition to var sub-telomeric domains. This eliminated possible effects from surrounding telomeric elements and removed the variability inherent in episomal systems. Studies with highly synchronized parasites revealed that the UpsA element possessed minimal activity in comparison with a heterologous (hrp3) promoter. This may well result from the integrated UpsA promoter being largely silenced by the neighboring cg6 promoter. Our analyses also revealed that the DownsA 3’ untranslated region further decreased the luciferase activity from both cassettes, whereas the var A intron repressed the UpsA promoter specifically. By applying multivariate analysis over the entire cell cycle, we confirmed the significance of these cis-elements and found the parasite stage to be the major factor regulating UpsA promoter activity. Additionally, we observed that the UpsA promoter was capable of nucleating reversible silencing that spread to a downstream promoter. We believe these studies are the first to analyze promoter activity of Group A var genes which have been implicated in severe malaria, and support the model that var introns can further suppress var expression. These data also suggest an important suppressive role for the DownsA terminator. Our findings imply the existence of multiple levels of var gene regulation in addition to intrinsic promoter-dependent silencing. PMID:19463825

Prevalence, bioserotyping and antibiotic resistance of pathogenic Yersinia enterocolitica detected in pigs at slaughter in Sardinia.

PubMed

Fois, Federica; Piras, Francesca; Torpdahl, Mia; Mazza, Roberta; Ladu, Daniela; Consolati, Simonetta G; Spanu, Carlo; Scarano, Christian; De Santis, Enrico P L

2018-06-13

The aims of the present study were to determine Yersinia enterocolitica prevalence in finishing pigs and piglets at slaughter and to characterize the isolates in terms of bioserotype, virulence profile, antimicrobial susceptibility and genetic diversity. During the years 2013-2014, nine pig slaughterhouses placed in Sardinia (Italy) were visited twice, in order to collect animal samples and scalding water. Overall, 609 samples respectively of tonsils (126), colon content (161), mesenteric lymph nodes (161) and carcass surfaces (161) were collected from 126 finishing pigs and 35 piglets. Moreover, 18 scalding water samples were collected. Samples were analyzed for the detection of Y. enterocolitica according to ISO 10273-2003 standard (with some modifications). With regard to finishing pigs, Y. enterocolitica was detected in 11.9% of colon content samples, 3.2% of tonsils and 2.4% of lymph nodes. In piglets, Y. enterocolitica prevalence was 8.6% in colon content and 2.8% lymph nodes samples. Y. enterocolitica was not detected from carcass surface samples of both finishing pigs and piglets and from scalding water samples. Isolates were bio- and serotyped, tested for the presence of four virulence genes by PCR (ail, ystA, ystB and inv) and for antimicrobial resistance by disc-diffusion method. Among 47 confirmed isolates, 33 (70.2%) belonged to bio-serotype 4:O3, 7 (14.9%) to bio-serotype 2/O:5 and 7 (14.9%) to bio-serotype 1A. Bio-serotype 1A was detected only in isolates of piglets' samples. In bio-serotype 4/O:3 isolates the most common virulence genes were ystA (97.0%), ail (84.8%) and inv (78.8%). In bio-serotype 2/O:5, ail, inv and ystA genes were detected in all of the isolates. All bio-serotype 1A isolates were ystB positive (lacking ail, inv and ystA). All isolates were susceptible to cefotaxime, ceftazidime, chloramphenicol, ciprofloxacin, enrofloxacin, gentamicin, nalidixic acid, sulphonamide, tetracycline and trimethoprim-sulphametoxazole. Resistances to ampicillin and cefalothin were the most common (100%), followed by amoxicillin/clavulanic acid (83.0%) and streptomycin (4.3%). Resistance to amoxicillin/clavulanic acid was detected in 57% of bio-serotype 4/O:3 isolates, 71% of bio-serotype 1A and 100% of bio-serotype 2/O:5 isolates. Two bio-serotype 4/O:3 isolates (6%) were resistant to streptomycin. Thirty-two pathogenic Y. enterocolitica isolates were tested by NotI-PFGE, which identified 5 patterns among bio-serotype 4/O:3 isolates and 2 patterns among bio-serotype 2/O:5 isolates. This study provides epidemiological data about human pathogenic Y. enterocolitica and highlight the role of pigs as a potential source of infection for the consumers in Sardinia. Copyright © 2018. Published by Elsevier B.V.

Animal Salmonella surveillance in Peninsular Malaysia, 1981-1985.

PubMed Central

Joseph, P. G.; Sivanandan, S. P.; Yee, H. T.

1988-01-01

During the 5-year (1981-5) surveillance period, 2322 salmonella isolations were recorded from animals and other non-human sources in Peninsular Malaysia. This was an increase of 356% over the preceding 5-year period. The 83 serotypes isolated were recovered from 41 sources. Of these 34 were new serotypes bringing the total number of serotypes isolated from non-human sources to date up 97. Food animals and edible animal products accounted for 92.2% of the total isolations, with cattle and beef accounting for 70% of the total. Salmonella dublin was the most frequently isolated serotype, whereas S. typhimurium had the widest zoological distribution. More than 80% of the non-human salmonella serotypes have also been reported in man in this country. PMID:3378581

Serotype IV and invasive group B Streptococcus disease in neonates, Minnesota, USA, 2000-2010.

PubMed

Ferrieri, Patricia; Lynfield, Ruth; Creti, Roberta; Flores, Aurea E

2013-04-01

Group B Streptococcus (GBS) is a major cause of invasive disease in neonates in the United States. Surveillance of invasive GBS disease in Minnesota, USA, during 2000-2010 yielded 449 isolates from 449 infants; 257 had early-onset (EO) disease (by age 6 days) and 192 late-onset (LO) disease (180 at age 7-89 days, 12 at age 90-180 days). Isolates were characterized by capsular polysaccharide serotype and surface-protein profile; types III and Ia predominated. However, because previously uncommon serotype IV constitutes 5/31 EO isolates in 2010, twelve type IV isolates collected during 2000-2010 were studied further. By pulsed-field gel electrophoresis, they were classified into 3 profiles; by multilocus sequence typing, representative isolates included new sequence type 468. Resistance to clindamycin or erythromycin was detected in 4/5 serotype IV isolates. Emergence of serotype IV GBS in Minnesota highlights the need for serotype prevalence monitoring to detect trends that could affect prevention strategies.

Seroprevalence study of Equine rhinitis B virus (ERBV) in Australian weanling horses using serotype-specific ERBV enzyme-linked immunosorbent assays.

PubMed

Horsington, Jacquelyn; Hartley, Carol A; Gilkerson, James R

2013-09-01

Respiratory infections are a major burden in the performance horse industry. Equine rhinitis B virus (ERBV) has been isolated from horses displaying clinical respiratory disease, and ERBV-neutralizing antibodies have been detected in 50-80% of horses in reported surveys. Current ERBV isolation and detection methods may underestimate the number of ERBV-positive animals and do not identify multiple serotype infections. The aim of the current study was to develop a serotyping ERBV antibody-detection enzyme-linked immunosorbent assay (ELISA) and examine the seroprevalence of ERBV in a group of Australian weanling horses. ELISAs with high sensitivity and specificity were developed. The seroprevalence of ERBV in the weanling horses was high (74-86%); ERBV-3 antibodies were most prevalent (58-62%) and ERBV-2 antibodies were least prevalent (10-16%). Many horses were seropositive to 2 or more serotypes. All 3 serotypes of ERBV were detected, and concurrent positivity to multiple serotypes was common.

Salmonella serotypes in reptiles and humans, French Guiana.

PubMed

Gay, Noellie; Le Hello, Simon; Weill, François-Xavier; de Thoisy, Benoit; Berger, Franck

2014-05-14

In French Guiana, a French overseas territory located in the South American northern coast, nearly 50% of Salmonella serotypes isolated from human infections belong to serotypes rarely encountered in metropolitan France. A reptilian source of contamination has been investigated. Between April and June 2011, in the area around Cayenne, 151 reptiles were collected: 38 lizards, 37 snakes, 32 turtles, 23 green iguanas and 21 caimans. Cloacal swab samples were collected and cultured. Isolated Salmonella strains were identified biochemically and serotyped. The overall carriage frequency of carriage was 23.2% (95% confidence interval: 16.7-30.4) with 23 serotyped strains. The frequency of Salmonella carriage was significantly higher for wild reptiles. Near two-thirds of the Salmonella serotypes isolated from reptiles were also isolated from patients in French Guiana. Our results highlight the risk associated with the handling and consumption of reptiles and their role in the spread of Salmonella in the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Botulinum neurotoxin serotypes detected by electrochemical impedance spectroscopy.

PubMed

Savage, Alison C; Buckley, Nicholas; Halliwell, Jennifer; Gwenin, Christopher

2015-05-06

Botulinum neurotoxin is one of the deadliest biological toxins known to mankind and is able to cause the debilitating disease botulism. The rapid detection of the different serotypes of botulinum neurotoxin is essential for both diagnosis of botulism and identifying the presence of toxin in potential cases of terrorism and food contamination. The modes of action of botulinum neurotoxins are well-established in literature and differ for each serotype. The toxins are known to specifically cleave portions of the SNARE proteins SNAP-25 or VAMP; an interaction that can be monitored by electrochemical impedance spectroscopy. This study presents a SNAP-25 and a VAMP biosensors for detecting the activity of five botulinum neurotoxin serotypes (A-E) using electrochemical impedance spectroscopy. The biosensors are able to detect concentrations of toxins as low as 25 fg/mL, in a short time-frame compared with the current standard methods of detection. Both biosensors show greater specificity for their compatible serotypes compared with incompatible serotypes and denatured toxins.

Botulinum Neurotoxin Serotypes Detected by Electrochemical Impedance Spectroscopy

PubMed Central

Savage, Alison C.; Buckley, Nicholas; Halliwell, Jennifer; Gwenin, Christopher

2015-01-01

Botulinum neurotoxin is one of the deadliest biological toxins known to mankind and is able to cause the debilitating disease botulism. The rapid detection of the different serotypes of botulinum neurotoxin is essential for both diagnosis of botulism and identifying the presence of toxin in potential cases of terrorism and food contamination. The modes of action of botulinum neurotoxins are well-established in literature and differ for each serotype. The toxins are known to specifically cleave portions of the SNARE proteins SNAP-25 or VAMP; an interaction that can be monitored by electrochemical impedance spectroscopy. This study presents a SNAP-25 and a VAMP biosensors for detecting the activity of five botulinum neurotoxin serotypes (A–E) using electrochemical impedance spectroscopy. The biosensors are able to detect concentrations of toxins as low as 25 fg/mL, in a short time-frame compared with the current standard methods of detection. Both biosensors show greater specificity for their compatible serotypes compared with incompatible serotypes and denatured toxins. PMID:25954998

Phytochemical characterization of several hawthorn (Crataegus spp.) species sampled from the Eastern Mediterranean region of Turkey.

PubMed

Calişkan, Oğuzhan; Gündüz, Kazim; Serçe, Sedat; Toplu, Celil; Kamiloğlu, Onder; Sengül, Memnune; Ercişli, Sezai

2012-01-01

We evaluated the total phenolic content, antioxidant capacity as well as antioxidant activity of five Crataegus species (A1, A2, Y1, Y2, Y4 accessions of Crataegus aronia var. aronia; B2, B3, B5, B6, B7, B9, Y5 accessions of C. aronia var. dentata; B10 accession of C. aronia var. minuta; Y3 accession of Crataegus orientalis var. orientalis and A3 accession of Crataegus monogyna subsp. azarella). Antioxidant activity and total phenolic content of fruits were determined by β-carotene bleaching and Folin-Ciocalteu assays. Antioxidant capacity was determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. C. monogyna subsp. azarella had the highest total phenol, antioxidant activity and antioxidant capacity of 55.2 mg gallic acid equivalents (GAE)/g dry weight (DW), 81.9% and 31.2%, respectively. C. aronia var. aronia was found to have the lowest total phenolic content (35.7 mg GAE/g DW). The antioxidant activities of fruit extracts increased in the order of C. orientalis var. orientalis < C. aronia var. minuta < C. aronia var. dentata < C. aronia var. aronia < C. monogyna subsp. azarella according to β-carotene/linoleic acid assay. In recent years, C. aronia var. dentata has gained importance as a commercial species in this region. B3 and B7 accessions had fruit weight more than 14 g, and considerable total phenol content, antioxidant activity and antioxidant capacity. This investigation shows the potential value of hawthorn fruit species as a good source of natural antioxidants and that consumption of hawthorn fruit or its products may contribute substantial amounts of antioxidants to the diet.

Phytochemical characterization of several hawthorn (Crataegus spp.) species sampled from the Eastern Mediterranean region of Turkey

PubMed Central

Çalişkan, Oğuzhan; Gündüz, Kazim; Serçe, Sedat; Toplu, Celil; Kamiloğlu, Önder; Şengül, Memnune; Ercişli, Sezai

2012-01-01

Background: We evaluated the total phenolic content, antioxidant capacity as well as antioxidant activity of five Crataegus species (A1, A2, Y1, Y2, Y4 accessions of Crataegus aronia var. aronia; B2, B3, B5, B6, B7, B9, Y5 accessions of C. aronia var. dentata; B10 accession of C. aronia var. minuta; Y3 accession of Crataegus orientalis var. orientalis and A3 accession of Crataegus monogyna subsp. azarella). Materials and Methods: Antioxidant activity and total phenolic content of fruits were determined by β-carotene bleaching and Folin–Ciocalteu assays. Antioxidant capacity was determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Results: C. monogyna subsp. azarella had the highest total phenol, antioxidant activity and antioxidant capacity of 55.2 mg gallic acid equivalents (GAE)/g dry weight (DW), 81.9% and 31.2%, respectively. C. aronia var. aronia was found to have the lowest total phenolic content (35.7 mg GAE/g DW). The antioxidant activities of fruit extracts increased in the order of C. orientalis var. orientalis < C. aronia var. minuta < C. aronia var. dentata < C. aronia var. aronia < C. monogyna subsp. azarella according to β-carotene/linoleic acid assay. In recent years, C. aronia var. dentata has gained importance as a commercial species in this region. B3 and B7 accessions had fruit weight more than 14 g, and considerable total phenol content, antioxidant activity and antioxidant capacity. Conclusion: This investigation shows the potential value of hawthorn fruit species as a good source of natural antioxidants and that consumption of hawthorn fruit or its products may contribute substantial amounts of antioxidants to the diet. PMID:22438658

Mapping the Human Memory B Cell and Serum Neutralizing Antibody Responses to Dengue Virus Serotype 4 Infection and Vaccination

PubMed Central

Nivarthi, Usha K.; Kose, Nurgun; Sapparapu, Gopal; Widman, Douglas; Gallichotte, Emily; Pfaff, Jennifer M.; Doranz, Benjamin J.; Weiskopf, Daniela; Sette, Alessandro; Durbin, Anna P.; Whitehead, Steve S.; Baric, Ralph

2016-01-01

ABSTRACT The four dengue virus (DENV) serotypes are mosquito-borne flaviviruses responsible for dengue fever and dengue hemorrhagic fever. People exposed to DENV develop antibodies (Abs) that strongly neutralize the serotype responsible for infection. Historically, infection with DENV serotype 4 (DENV4) has been less common and less studied than infections with the other three serotypes. However, DENV4 has been responsible for recent large and sustained epidemics in Asia and Latin America. The neutralizing antibody responses and the epitopes targeted against DENV4 have not been characterized in human infection. In this study, we mapped and characterized epitopes on DENV4 recognized by neutralizing antibodies in people previously exposed to DENV4 infections or to a live attenuated DENV4 vaccine. To study the fine specificity of DENV4 neutralizing human antibodies, B cells from two people exposed to DENV4 were immortalized and screened to identify DENV-specific clones. Two human monoclonal antibodies (MAbs) that neutralized DENV4 were isolated, and their epitopes were finely mapped using recombinant viruses and alanine scan mutation array techniques. Both antibodies bound to quaternary structure epitopes near the hinge region between envelope protein domain I (EDI) and EDII. In parallel, to characterize the serum neutralizing antibody responses, convalescence-phase serum samples from people previously exposed to primary DENV4 natural infections or a monovalent DENV4 vaccine were analyzed. Natural infection and vaccination also induced serum-neutralizing antibodies that targeted similar epitope domains at the EDI/II hinge region. These studies defined a target of neutralizing antigenic site on DENV4 targeted by human antibodies following natural infection or vaccination. IMPORTANCE The four serotypes of dengue virus are the causative agents of dengue fever and dengue hemorrhagic fever. People exposed to primary DENV infections develop long-term neutralizing antibody responses, but these principally recognize only the infecting serotype. An effective vaccine against dengue should elicit long-lasting protective antibody responses to all four serotypes simultaneously. We and others have defined antigenic sites on the envelope (E) protein of viruses of dengue virus serotypes 1, 2, and 3 targeted by human neutralizing antibodies. The epitopes on DENV4 E protein targeted by the human neutralizing antibodies and the mechanisms of serotype 4 neutralization are poorly understood. Here, we report the properties of human antibodies that neutralize dengue virus serotype 4. People exposed to serotype 4 infections or a live attenuated serotype 4 vaccine developed neutralizing antibodies that bound to similar sites on the viral E protein. These studies have provided a foundation for developing and evaluating DENV4 vaccines. PMID:28031369

Evaluation of a 15-valent Pneumococcal Conjugate Vaccine in an Adult Rhesus Macaque Immunogenicity Model

PubMed Central

Xie, Jinfu; Kaufhold, Robin; Mcguinness, Debra; Zhang, Yuhua; Smith, William; Giovarelli, Cecelia; Winters, Michael; Musey, Luwy; Kosinski, Michael; Skinner, Julie

2017-01-01

Abstract Background Streptococcus pneumoniae (pneumococcus) is a leading cause of a variety of diseases, including bacteremia, meningitis, and pneumonia, among older adults in the United States. Immunization with pneumococcal vaccines is an effective way to prevent these diseases. In this study, we evaluated the immunogenicity of 15-valent pneumococcal conjugate vaccine (PCV15) in adult rhesus macaques. Methods Animals were intramuscularly immunized with PNEUMOVAX® 23 and PCV15 vaccine (5 animals/group) and sera were collected before immunization and 30, 60, and 90 days after the immunization. Sera were assayed using multiplexed electrochemiluminescent (ECL) assays to measure serotype-specific IgG antibodies to all vaccine serotypes and multiplexed opsonophagocytic killing assays (MOPA) to measure functional antibody responses to 15 vaccine serotypes. Results At day 30 post immunization, 16 out of the 23 serotypes in PNEUMOVAX 23 groups induced statistically significant higher ECL titers compared with pre bleed, ranging from 1.6-fold (19A) to 28.3-fold (15B). Compared with PNEUMOVAX 23, PCV15 induced much higher ECL titers. Thirteen out of the 15 serotypes in PCV15 groups induced statistically significant higher ECL titers compared with pre bleed, ranging from 7.4-fold (14) to 47.3-fold (4). The ECL antibody titers gradually decreased from day 30 to day 90 for both groups. We also compared the functional MOPA titers of the day 30 sera compared with pre bleed for 15 vaccine serotypes. Out of the 14 common vaccine serotypes, 7 serotypes in the PNEUMOVAX 23 immunized macaques had a >4 fold increase in MOPA titer, ranging from 4-fold (22F) to 3902-fold (33F) and 11 serotypes in the PCV15 immunized macaques had a >4-fold increase in MOPA titer, ranging from 6.3-fold (23F) to 4445-fold (7F). Twelve out of the 14 common serotypes in PCV15 group had higher MOPA titers compared with the PNEUMOVAX 23 group, although they didn’t reach statistical significance due to high variability. Conclusion These data demonstrate that a single dose of PCV15 is highly immunogenic in adult rhesus macaques and has better immunogenicity for most common serotypes compared with PNEUMOVAX 23. However, PNEUMOVAX 23 offers broader serotype coverage with 9 additional serotypes contained in the vaccine. Disclosures J. Xie, Merck & Co. Inc: Employee, Salary; R. Kaufhold, Merck & Co. Inc: Employee, Salary; D. Mcguinness, Merck & Co. Inc: Employee, Salary; Y. Zhang, Merck & Co. Inc.: Employee, Salary; W. Smith, Merck & Co. Inc.: Employee, Salary; C. Giovarelli, Merck & Co. Inc.: Employee, Salary; M. Winters, Merck & Co. Inc: Employee, Salary; L. Musey, Merck & Co. Inc: Employee, Salary; M. Kosinski, Merck & Co. Inc: Employee, Salary; J. Skinner, Merck & Co. Inc: Employee, Salary

Comparative Analysis of VaR Estimation of Double Long-Memory GARCH Models: Empirical Analysis of China's Stock Market

NASA Astrophysics Data System (ADS)

Cao, Guangxi; Guo, Jianping; Xu, Lin

GARCH models are widely used to model the volatility of financial assets and measure VaR. Based on the characteristics of long-memory and lepkurtosis and fat tail of stock market return series, we compared the ability of double long-memory GARCH models with skewed student-t-distribution to compute VaR, through the empirical analysis of Shanghai Composite Index (SHCI) and Shenzhen Component Index (SZCI). The results show that the ARFIMA-HYGARCH model performance better than others, and at less than or equal to 2.5 percent of the level of VaR, double long-memory GARCH models have stronger ability to evaluate in-sample VaRs in long position than in short position while there is a diametrically opposite conclusion for ability of out-of-sample VaR forecast.

Influence ofArtemisia princeps var.orientalis components on callus induction and growth.

PubMed

Kil, B S; Yun, K W; Lee, S Y

1992-08-01

An in vitro study was performed to determine the potential application of tissue culture in determining allelopathic potentialof Artemisia princeps var.Orientalis (wormwood). Aqueous extracts and volatile substances ofA. princeps var.Orientalis were tested to determine their effects on callus induction and growth of several tested species. Extracts of 5%A. princeps var.Orientalis caused some reduction in concentration, induction, and growth of callus, although they looked normal, whereas the expiants of most receptor plants did not develop callus at higher concentration. Lettuce andEclipta prostrata were the most sensitive species, andA. princeps var.Orientalis was affected by its own extracts. The growth of calluses in MS 121 medium treated with essential oil ofA. princeps var.Orientalis was inhibited, and the degree of inhibition was proportional to the concentration of the essential oil.

The B Cell Response to Foot-and-Mouth Disease Virus in Cattle following Sequential Vaccination with Multiple Serotypes.

PubMed

Grant, Clare F J; Carr, B Veronica; Kotecha, Abhay; van den Born, Erwin; Stuart, David I; Hammond, John A; Charleston, Bryan

2017-05-01

Foot-and-mouth disease virus (FMDV) is a highly contagious viral disease. Antibodies are pivotal in providing protection against FMDV infection. Serological protection against one FMDV serotype does not confer interserotype protection. However, some historical data have shown that interserotype protection can be induced following sequential FMDV challenge with multiple FMDV serotypes. In this study, we have investigated the kinetics of the FMDV-specific antibody-secreting cell (ASC) response following homologous and heterologous inactivated FMDV vaccination regimes. We have demonstrated that the kinetics of the B cell response are similar for all four FMDV serotypes tested following a homologous FMDV vaccination regime. When a heterologous vaccination regime was used with the sequential inoculation of three different inactivated FMDV serotypes (O, A, and Asia1 serotypes) a B cell response to FMDV SAT1 and serotype C was induced. The studies also revealed that the local lymphoid tissue had detectable FMDV-specific ASCs in the absence of circulating FMDV-specific ASCs, indicating the presence of short-lived ASCs, a hallmark of a T-independent 2 (TI-2) antigenic response to inactivated FMDV capsid. IMPORTANCE We have demonstrated the development of intraserotype response following a sequential vaccination regime of four different FMDV serotypes. We have found indication of short-lived ASCs in the local lymphoid tissue, further evidence of a TI-2 response to FMDV. Copyright © 2017 American Society for Microbiology.

Structural elucidation of the O-antigen of the Shigella flexneri provisional serotype 88-893: structural and serological similarities with S. flexneri provisional serotype Y394 (1c).

PubMed

Foster, R A; Carlin, N I A; Majcher, M; Tabor, H; Ng, L-K; Widmalm, G

2011-05-01

The structure of the repeating unit of the O-antigen polysaccharide from Shigella flexneri provisional serotype 88-893 has been determined. (1)H and (13)C NMR spectroscopy as well as 2D NMR experiments were employed to elucidate the structure. The carbohydrate part of the hexasaccharide repeating unit is identical to the previously elucidated structure of the O-polysaccharide from S. flexneri prov. serotype Y394. The O-antigen of S. flexneri prov. serotype 88-893 carries 0.7 mol O-acetyl group per repeating unit located at O-2 of the 3-substituted rhamnosyl residue, as identified by H2BC and BS-CT-HMBC NMR experiments. The O-antigen polysaccharide is composed of hexasaccharide repeating units with the following structure: →2)-α-L-Rhap-(1→2)-α-L-Rhap-(1→3)-α-L-Rhap2Ac-(1→3)[α-D-Glcp-(1→2)-α-D-Glcp-(1→4)]-β-D-GlcpNAc-(1→. Serological studies showed that type antigens for the two provisional serotypes are identical; in addition 88-893 expresses S. flexneri group factor 6 antigen. We propose that provisional serotypes Y394 and 88-893 be designated as two new serotypes 7a and 7b, respectively, in the S. flexneri typing scheme. Copyright © 2011 Elsevier Ltd. All rights reserved.

Serotypes, Antibiotic Susceptibilities, and Multi-Locus Sequence Type Profiles of Streptococcus agalactiae Isolates Circulating in Beijing, China

PubMed Central

Ma, Xiu-hua; Song, Feng-li; Fan, Ling; Guo, Cui-mei; Shi, Wei; Yu, Sang-jie; Yao, Kai-hu; Yang, Yong-hong

2015-01-01

Background To investigate the serotypes, antibiotic susceptibilities, and multi-locus sequence type (MLST) profiles of Streptococcus agalactiae (S. agalactiae) in Beijing to provide references for the prevention and treatment of S. agalactiae infections. Methods All isolates were identified using the CAMP test and the latex-agglutination assay and serotyped using a Strep-B-Latex kit, after which they were assessed for antibiotic susceptibility, macrolide-resistance genes, and MLST profiles. Results In total, 56 S. agalactiae isolates were identified in 863 pregnant women (6.5%). Serotypes Ia, Ib, II, III, and V were identified, among which types III (32.1%), Ia (17.9%), Ib (16.1%), and V (14.3%) were the predominant serotypes. All isolates were susceptible to penicillin and ceftriaxone. The nonsusceptiblity rates measured for erythromycin, clarithromycin, azithromycin, telithromycin, clindamycin, tetracycline, and levofloxacin were 85.7%, 92.9%, 98.2%, 30.4%, 73.2%, 91%, and 39.3%, respectively. We identified 14 sequence types (STs) for the 56 isolates, among which ST19 (30.4%) was predominant. The rate of fluoroquinolone resistance was higher in serotype III than in the other serotypes. Among the 44 erythromycin-resistant isolates, 32 (72.7%) carried ermB. Conclusion S. agalactiae isolates of the serotypes Ia, Ib, III, and V are common in Beijing. Among the S. agalactiae isolates, the macrolide and clindamycin resistance rates are extremely high. Most of the erythromycin-resistant isolates carry ermB. PMID:25781346

Antibody-Mediated Complement C3b/iC3b Binding to Group B Streptococcus in Paired Mother and Baby Serum Samples in a Refugee Population on the Thailand-Myanmar Border

PubMed Central

Herbert, Jenny; Thomas, Stephen; Brookes, Charlotte; Turner, Claudia; Turner, Paul; Nosten, Francois; Le Doare, Kirsty; Hudson, Michael; Heath, Paul T.; Gorringe, Andrew

2015-01-01

Streptococcus agalactiae (group B streptococcus [GBS]) is the leading cause of neonatal sepsis and meningitis. In this study, we determined antibody-mediated deposition of complement C3b/iC3b onto the bacterial cell surface of GBS serotypes Ia, Ib, II, III, and V. This was determined for 520 mother and umbilical cord serum sample pairs obtained at the time of birth from a population on the Thailand-Myanmar border. Antibody-mediated deposition of complement C3b/iC3b was detected to at least one serotype in 91% of mothers, despite a known carriage rate in this population of only 12%. Antibody-mediated C3b/iC3b deposition corresponded to known carriage rates, with the highest levels of complement deposition observed onto the most prevalent serotype (serotype II) followed by serotypes Ia, III, V, and Ib. Finally, neonates born to mothers carrying serotype II GBS at the time of birth showed higher antibody-mediated C3b/iC3b deposition against serotype II GBS than neonates born to mothers with no serotype II carriage. Assessment of antibody-mediated C3b/iC3b deposition against GBS may provide insights into the seroepidemiology of anti-GBS antibodies in mothers and infants in different populations. PMID:25589553

Survey of poliovirus antibodies in Borno and Yobe States, North-Eastern Nigeria.

PubMed

Gofama, Mustapha Modu; Verma, Harish; Abdullahi, Hamisu; Molodecky, Natalie A; Craig, Kehinde T; Urua, Utibe-Abasi; Garba, Mohammed Ashir; Alhaji, Mohammed Arab; Weldon, William C; Oberste, M Steven; Braka, Fiona; Muhammad, Ado J G; Sutter, Roland W

2017-01-01

Nigeria remains one of only three polio-endemic countries in the world. In 2016, after an absence of 2 years, wild poliovirus serotype 1 was again detected in North-Eastern Nigeria. To better guide programmatic action, we assessed the immunity status of infants and children in Borno and Yobe states, and evaluated the impact of recently introduced inactivated poliovirus vaccine (IPV) on antibody seroprevalence. We conducted a facility-based study of seroprevalence to poliovirus serotypes 1, 2 and 3 among health-seeking patients in two sites each of Borno and Yobe States. Enrolment was conducted amongst children 6-9 and 36-47 months of age attending the paediatrics outpatient department of the selected hospitals in the two states between 11 January and 5 February 2016. Detailed demographic and immunization history of the child was taken and an assessment of the child's health and nutritional state was conducted via physical examination. Blood was collected to test for levels of neutralizing antibody titres against the three poliovirus serotypes. The seroprevalence in the two age groups, potential determinants of seropositivity and the impact of one dose of IPV on humoral immunity were assessed. A total of 583 subjects were enrolled and provided sufficient quantities of serum for testing. Among 6-9-month-old infants, the seroprevalence was 81% (74-87%), 86% (79-91%), and 72% (65-79%) in Borno State, and 75% (67-81%), 74% (66-81%) and 69% (61-76%) in Yobe States, for serotypes-1, 2 and 3, respectively. Among children aged 36-47 months, the seroprevalence was >90% in both states for all three serotypes, with the exception of type 3 seroprevalence in Borno [87% (80-91%)]. Median reciprocal anti-polio neutralizing antibody titers were consistently >900 for serotypes 1 and 2 across age groups and states; with lower estimates for serotype 3, particularly in Borno. IPV received in routine immunization was found to be a significant determinant of seropositivity and anti-polio neutralizing antibodies among 6-9-month-old infants for serotypes 1 and 3, but demonstrated a non-significant positive association for serotype 2. Children receiving IPV through SIAs demonstrated significantly higher anti-polio neutralizing antibodies for serotypes 1 and 3. The seroprevalence to poliovirus remains suboptimal in both Borno and Yobe States in Nigeria. The low seroprevalence facilitated the continued transmission of both wild serotype 1 and serotype 2 circulating vaccine-derived poliovirus detected in Borno State in 2016. Further efforts are necessary to improve the immunity status of these populations to ensure sufficient population immunity to interrupt transmission.

Semi-nonparametric VaR forecasts for hedge funds during the recent crisis

NASA Astrophysics Data System (ADS)

Del Brio, Esther B.; Mora-Valencia, Andrés; Perote, Javier

2014-05-01

The need to provide accurate value-at-risk (VaR) forecasting measures has triggered an important literature in econophysics. Although these accurate VaR models and methodologies are particularly demanded for hedge fund managers, there exist few articles specifically devoted to implement new techniques in hedge fund returns VaR forecasting. This article advances in these issues by comparing the performance of risk measures based on parametric distributions (the normal, Student’s t and skewed-t), semi-nonparametric (SNP) methodologies based on Gram-Charlier (GC) series and the extreme value theory (EVT) approach. Our results show that normal-, Student’s t- and Skewed t- based methodologies fail to forecast hedge fund VaR, whilst SNP and EVT approaches accurately success on it. We extend these results to the multivariate framework by providing an explicit formula for the GC copula and its density that encompasses the Gaussian copula and accounts for non-linear dependences. We show that the VaR obtained by the meta GC accurately captures portfolio risk and outperforms regulatory VaR estimates obtained through the meta Gaussian and Student’s t distributions.

Protective Antibodies against Placental Malaria and Poor Outcomes during Pregnancy, Benin

PubMed Central

Denoeud-Ndam, Lise; Doritchamou, Justin; Viwami, Firmine; Salanti, Ali; Nielsen, Morten A.; Fievet, Nadine; Massougbodji, Achille; Luty, Adrian J.F.; Deloron, Philippe

2015-01-01

Placental malaria is caused by Plasmodium falciparum–infected erythrocytes that bind to placental tissue. Binding is mediated by VAR2CSA, a parasite antigen coded by the var gene, which interacts with chondroitin sulfate A (CSA). Consequences include maternal anemia and fetal growth retardation. Antibody-mediated immunity to placental malaria is acquired during successive pregnancies, but the target of VAR2CSA-specific protective antibodies is unclear. We assessed VAR2CSA-specific antibodies in pregnant women and analyzed their relationships with protection against placental infection, preterm birth, and low birthweight. Antibody responses to the N-terminal region of VAR2CSA during early pregnancy were associated with reduced risks for infections and low birthweight. Among women infected during pregnancy, an increase in CSA binding inhibition was associated with reduced risks for placental infection, preterm birth, and low birthweight. These data suggest that antibodies against VAR2CSA N-terminal region mediate immunity to placental malaria and associated outcomes. Our results validate current vaccine development efforts with VAR2CSA N-terminal constructs. PMID:25898123

Serological purification of polysaccharide antigens from Streptococcus mutans serotypes a and d: characterization of multiple antigenic determinants.

PubMed

Linzer, R; Mukasa, H; Slade, H D

1975-10-01

The polysaccharide antigen preparations from serotype a and serotype d strains of Streptococcus mutans contained both a serotype-specific antigenic determinant and a common a-d antigenic determinant, as demonstrated by agar gel diffusion studies and a quantitative cross-precipitin assay. The chromatographically purified antigens were isolated by a method which depended on their serological specificity to determine if these two antigenic determinants were located on the same molecule. The a and d polysaccharides were recovered from specific antigen-antibody complexes and characterized with respect to their immunological specificity and chemical composition. Agar gel diffusion tests demonstrated that, in both the a and d preparations, the serotype-specific antigenic determinant and the common a-d antigenic determinant were present in one molecule.

Serotype- and virulence-associated gene profile of Streptococcus suis isolates from pig carcasses in Chiang Mai Province, Northern Thailand.

PubMed

Wongsawan, Kanruethai; Gottschalk, Marcelo; Tharavichitkul, Prasit

2015-02-01

In this present study, the serotype of 40 Streptococcus suis isolates from submaxillary glands of pig carcasses sold in wet markets in Chiang Mai Province, northern Thailand, was investigated. Eleven serotypes, including types 2, 3, 4, 5, 7, 8, 9, 17, 21, 22 and 31, were found in the isolates by a Multiplex PCR combined with serum agglutination. Of the eleven serotypes present, type 3 was the most prevalent, while types 2, 4, 5 and 21 were of primary interest due to their human isolate serotype. The mrp+/epf - /sly - genotype was found to be the most prevalent genotype. This study indicates the importance of effective control of human S. suis infection due to raw pork or pig carcass handling in northern Thailand.

Antimicrobial Properties of Biofunctionalized Silver Nanoparticles on Clinical Isolates of Streptococcus mutans and Its Serotypes

PubMed Central

Martínez-Robles, Ángel Manuel; Loyola-Rodríguez, Juan Pablo; Zavala-Alonso, Norma Verónica; Martinez-Martinez, Rita Elizabeth; Ruiz, Facundo; Lara-Castro, René Homero; Donohué-Cornejo, Alejandro; Reyes-López, Simón Yobanny; Espinosa-Cristóbal, León Francisco

2016-01-01

(1) Background: Streptococcus mutans (S. mutans) is the principal pathogen involved in the formation of dental caries. Other systemic diseases have also been associated with specific S. mutans serotypes (c, e, f, and k). Silver nanoparticles (SNP) have been demonstrated to have good antibacterial effects against S. mutans; therefore, limited studies have evaluated the antimicrobial activity of biofunctionalized SNP on S. mutans serotypes. The purpose of this work was to prepare and characterize coated SNP using two different organic components and to evaluate the antimicrobial activity of SNP in clinical isolates of S. mutans strains and serotypes; (2) Methods: SNP with bovine serum albumin (BSA) or chitosan (CS) coatings were prepared and the physical, chemical and microbiological properties of SNP were evaluated; (3) Results: Both types of coated SNP showed antimicrobial activity against S. mutans bacteria and serotypes. Better inhibition was associated with smaller particles and BSA coatings; however, no significant differences were found between the different serotypes, indicating a similar sensitivity to the coated SNP; (4) Conclusion: This study concludes that BSA and CS coated SNP had good antimicrobial activity against S. mutans strains and the four serotypes, and this study suggest the widespread use of SNP as an antimicrobial agent for the inhibition of S. mutans bacteria. PMID:28335264

Investigating the candidacy of the serotype specific rhamnan polysaccharide based glycoconjugates to prevent disease caused by the dental pathogen Streptococcus mutans.

PubMed

St Michael, Frank; Yang, Qingling; Cairns, Chantelle; Vinogradov, Evgeny; Fleming, Perry; Hayes, Alexander C; Aubry, Annie; Cox, Andrew D

2018-02-01

Dental caries remains a major health issue and the Gram-positive bacterium Streptococcus mutans is considered as the major pathogen causing caries. More recently, S. mutans has been recognised as a cause of endocarditis, ulcerative colitis and fatty acid liver disease along with the likelihood of increased cerebral hemorrhage following a stroke if S. mutans is present systemically. We initiated this study to examine the vaccine candidacy of the serotype specific polysaccharides elaborated by S. mutans. We have confirmed the carbohydrate structures for the serotype specific rhamnan containing polysaccharides from serotypes c, f and k. We have prepared glycoconjugate vaccines using the rhamnan containing polymers from serotypes f and k and immunised mice and rabbits. We consistently obtained a robust immune response to the glycoconjugates with cross-reactivity consistent with the structural similarities of the polymers from the different serotypes. We developed an opsonophagocytic assay which illustrated the ability of the post-immune sera to facilitate opsonophagocytic killing of the homologous and heterologous serotypes at titers consistent with the structural homologies. We conclude that glycoconjugates of the rhamnan polymers of S. mutans are a potential vaccine candidate to target dental caries and other sequelae following the escape of S. mutans from the oral cavity.

Antimicrobial Properties of Biofunctionalized Silver Nanoparticles on Clinical Isolates of Streptococcus mutans and Its Serotypes.

PubMed

Martínez-Robles, Ángel Manuel; Loyola-Rodríguez, Juan Pablo; Zavala-Alonso, Norma Verónica; Martinez-Martinez, Rita Elizabeth; Ruiz, Facundo; Lara-Castro, René Homero; Donohué-Cornejo, Alejandro; Reyes-López, Simón Yobanny; Espinosa-Cristóbal, León Francisco

2016-07-22

(1) Background: Streptococcus mutans ( S. mutans ) is the principal pathogen involved in the formation of dental caries. Other systemic diseases have also been associated with specific S. mutans serotypes ( c , e , f , and k ). Silver nanoparticles (SNP) have been demonstrated to have good antibacterial effects against S. mutans ; therefore, limited studies have evaluated the antimicrobial activity of biofunctionalized SNP on S. mutans serotypes. The purpose of this work was to prepare and characterize coated SNP using two different organic components and to evaluate the antimicrobial activity of SNP in clinical isolates of S. mutans strains and serotypes; (2) Methods: SNP with bovine serum albumin (BSA) or chitosan (CS) coatings were prepared and the physical, chemical and microbiological properties of SNP were evaluated; (3) Results: Both types of coated SNP showed antimicrobial activity against S. mutans bacteria and serotypes. Better inhibition was associated with smaller particles and BSA coatings; however, no significant differences were found between the different serotypes, indicating a similar sensitivity to the coated SNP; (4) Conclusion: This study concludes that BSA and CS coated SNP had good antimicrobial activity against S. mutans strains and the four serotypes, and this study suggest the widespread use of SNP as an antimicrobial agent for the inhibition of S. mutans bacteria.

Epigenetic regulation of serotype expression antagonizes transcriptome dynamics in Paramecium tetraurelia

PubMed Central

Cheaib, Miriam; Dehghani Amirabad, Azim; Nordström, Karl J. V.; Schulz, Marcel H.; Simon, Martin

2015-01-01

Phenotypic variation of a single genotype is achieved by alterations in gene expression patterns. Regulation of such alterations depends on their time scale, where short-time adaptations differ from permanently established gene expression patterns maintained by epigenetic mechanisms. In the ciliate Paramecium, serotypes were described for an epigenetically controlled gene expression pattern of an individual multigene family. Paradoxically, individual serotypes can be triggered in Paramecium by alternating environments but are then stabilized by epigenetic mechanisms, thus raising the question to which extend their expression follows environmental stimuli. To characterize environmental adaptation in the context of epigenetically controlled serotype expression, we used RNA-seq to characterize transcriptomes of serotype pure cultures. The resulting vegetative transcriptome resource is first analysed for genes involved in the adaptive response to the altered environment. Secondly, we identified groups of genes that do not follow the adaptive response but show co-regulation with the epigenetically controlled serotype system, suggesting that their gene expression pattern becomes manifested by similar mechanisms. In our experimental set-up, serotype expression and the entire group of co-regulated genes were stable among environmental changes and only heat-shock genes altered expression of these gene groups. The data suggest that the maintenance of these gene expression patterns in a lineage represents epigenetically controlled robustness counteracting short-time adaptation processes. PMID:26231545

Ganglioside GM1 mimicry in Campylobacter strains from sporadic infections in the United States.

PubMed

Nachamkin, I; Ung, H; Moran, A P; Yoo, D; Prendergast, M M; Nicholson, M A; Sheikh, K; Ho, T; Asbury, A K; McKhann, G M; Griffin, J W

1999-05-01

To determine whether GM1-like epitopes in Campylobacter species are specific to O serotypes associated with Guillain-Barré syndrome (GBS) or whether they are frequent among random Campylobacter isolates causing enteritis, 275 random enteritis-associated isolates of Campylobacter jejuni were analyzed. To determine whether GM1-like epitopes in Campylobacter species are specific to O serotypes associated with Guillan-Barre syndrome (GBS) or whether they are frequent among random Campylobacter isolates causing enteritis, 275 enteritis-associated isolates, randomly collected in the United States, were analyzed using a cholera-toxin binding assay [corrected]. Overall, 26.2% of the isolates were positive for the GM1-like epitope. Of the 36 different O serotypes in the sample, 21 (58.3%) contained no strains positive for GM1, whereas in 6 serotypes (16.7%), >50% of isolates were positive for GM1. GBS-associated serotypes were more likely to contain strains positive for GM1 than were non-GBS-associated serotypes (37.8% vs. 15.1%, P=.0116). The results suggest that humans are frequently exposed to strains exhibiting GM1-like mimicry and, while certain serotypes may be more likely to possess GM1-like epitopes, the presence of GM1-like epitopes on Campylobacter strains does not itself trigger GBS.

An evaluation of the Australian Rotavirus Surveillance Program.

PubMed

Roberts-Witteveen, April R; Patel, Mahomed S; Roche, Paul W

2008-09-01

The Australian Rotavirus Serotyping Program (ARSP) serotypes rotavirus isolates obtained from stool samples sent from Australian laboratories. In collaboration with ARSP the Australian Government Department of Health and Ageing evaluated the program for its utility and capacity to monitor effectiveness of the rotavirus vaccines recently introduced into the Australian National Immunisation Program. The system was described using ARSP annual reports and staff interviews. The attributes of the system were assessed by adapting standard guidelines for evaluating a surveillance system. Email surveys or face to face interviews were conducted with staff of ARSP, participating laboratories, rotavirus vaccine manufacturing companies and representatives of the Communicable Diseases Network Australia. The ability of the ARSP to monitor changes in rotavirus serotype epidemiology was assessed. ARSP serotypes rotavirus isolates received from participating laboratories at least bi-annually, with results being reported at least as often. Serotype analyses have informed formulation of rotavirus vaccines and contributed to forecasting the extent of outbreaks caused by novel serotypes. The ARSP will be able to monitor changes in rotavirus serotype epidemiology and identify probable vaccination failures. Enhancement of the representativeness and sensitivity of the system are needed for the data to remain useful in the public health context. Methods for transferring data between the program and state and territory health departments need to be developed.

Development and Characterization of Probe-Based Real Time Quantitative RT-PCR Assays for Detection and Serotyping of Foot-And-Mouth Disease Viruses Circulating in West Eurasia

PubMed Central

Jamal, Syed M.; Belsham, Graham J.

2015-01-01

Rapid and accurate diagnosis of foot-and-mouth disease (FMD) and virus serotyping are of paramount importance for control of this disease in endemic areas where vaccination is practiced. Ideally this virus characterization should be achieved without the need for virus amplification in cell culture. Due to the heterogeneity of FMD viruses (FMDVs) in different parts of the world, region specific diagnostic tests are required. In this study, hydrolysable probe-based real time reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays were developed for specific detection and serotyping of the FMDVs currently circulating in West Eurasia. These assays were evaluated, in parallel with pan-FMDV diagnostic assays and earlier serotype-specific assays, using field samples originating from Pakistan and Afghanistan containing FMD viruses belonging to different sublineages of O-PanAsia, A-Iran05 and Asia-1 (Group-II and Group-VII (Sindh-08)). In addition, field samples from Iran and Bulgaria, containing FMDVs belonging to the O-PanAsiaANT-10 sublineage were also tested. Each of the three primer/probe sets was designed to be specific for just one of the serotypes O, A and Asia-1 of FMDV and detected the RNA from the target viruses with cycle threshold (CT) values comparable with those obtained with the serotype-independent pan-FMDV diagnostic assays. No cross-reactivity was observed in these assays between the heterotypic viruses circulating in the region. The assays reported here have higher diagnostic sensitivity (100% each for serotypes O and Asia-1, and 92% [95% CI = 81.4–100%] for serotype A positive samples) and specificity (100% each for serotypes O, A and Asia-1 positive samples) for the viruses currently circulating in West Eurasia compared to the serotyping assays reported earlier. Comparisons of the sequences of the primers and probes used in these assays and the corresponding regions of the circulating viruses provided explanations for the poor recognition of some of the viruses by the earlier assays. These new assays should help in the early detection and typing of serotype O, A and Asia-1 FMDVs circulating in West Eurasia to enable improved disease control. PMID:26270532

Development and Characterization of Probe-Based Real Time Quantitative RT-PCR Assays for Detection and Serotyping of Foot-And-Mouth Disease Viruses Circulating in West Eurasia.

PubMed

Jamal, Syed M; Belsham, Graham J

2015-01-01

Rapid and accurate diagnosis of foot-and-mouth disease (FMD) and virus serotyping are of paramount importance for control of this disease in endemic areas where vaccination is practiced. Ideally this virus characterization should be achieved without the need for virus amplification in cell culture. Due to the heterogeneity of FMD viruses (FMDVs) in different parts of the world, region specific diagnostic tests are required. In this study, hydrolysable probe-based real time reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays were developed for specific detection and serotyping of the FMDVs currently circulating in West Eurasia. These assays were evaluated, in parallel with pan-FMDV diagnostic assays and earlier serotype-specific assays, using field samples originating from Pakistan and Afghanistan containing FMD viruses belonging to different sublineages of O-PanAsia, A-Iran05 and Asia-1 (Group-II and Group-VII (Sindh-08)). In addition, field samples from Iran and Bulgaria, containing FMDVs belonging to the O-PanAsiaANT-10 sublineage were also tested. Each of the three primer/probe sets was designed to be specific for just one of the serotypes O, A and Asia-1 of FMDV and detected the RNA from the target viruses with cycle threshold (CT) values comparable with those obtained with the serotype-independent pan-FMDV diagnostic assays. No cross-reactivity was observed in these assays between the heterotypic viruses circulating in the region. The assays reported here have higher diagnostic sensitivity (100% each for serotypes O and Asia-1, and 92% [95% CI = 81.4-100%] for serotype A positive samples) and specificity (100% each for serotypes O, A and Asia-1 positive samples) for the viruses currently circulating in West Eurasia compared to the serotyping assays reported earlier. Comparisons of the sequences of the primers and probes used in these assays and the corresponding regions of the circulating viruses provided explanations for the poor recognition of some of the viruses by the earlier assays. These new assays should help in the early detection and typing of serotype O, A and Asia-1 FMDVs circulating in West Eurasia to enable improved disease control.

Comparative study on the chemical composition, antioxidant properties and hypoglycaemic activities of two Capsicum annuum L. cultivars (Acuminatum small and Cerasiferum).

PubMed

Tundis, Rosa; Loizzo, Monica R; Menichini, Federica; Bonesi, Marco; Conforti, Filomena; Statti, Giancarlo; De Luca, Damiano; de Cindio, Bruno; Menichini, Francesco

2011-09-01

The present study aimed to evaluate for the first time the phenols, flavonoids, carotenoids, capsaicin and dihydrocapsaicin content and the antioxidant and hypoglycemic properties of Capsicum annuum var. acuminatum small and C. annuum var. cerasiferum air-dried fruits. The ethanol extract of C. annuum var. acuminatum small, characterized by the major content of total poliphenols, flavonoids, carotenoids and capsaicinoids, showed the highest radical scavenging activity (IC(50) of 152.9 μg/ml). On the contrary, C. annuum var. cerasiferum showed a significant antioxidant activity evaluated by the β-carotene bleaching test (IC(50) of 3.1 μg/ml). The lipophilic fraction of both C. annuum var. acuminatum and C. annuum var. cerasiferum exhibited an interesting and selective inhibitory activity against α-amylase (IC(50) of 6.9 and 20.1 μg/ml, respectively).

Design of inhibitors of thymidylate kinase from Variola virus as new selective drugs against smallpox.

PubMed

Guimarães, Ana P; de Souza, Felipe R; Oliveira, Aline A; Gonçalves, Arlan S; de Alencastro, Ricardo B; Ramalho, Teodorico C; França, Tanos C C

2015-02-16

Recently we constructed a homology model of the enzyme thymidylate kinase from Variola virus (VarTMPK) and proposed it as a new target to the drug design against smallpox. In the present work, we used the antivirals cidofovir and acyclovir as reference compounds to choose eleven compounds as leads to the drug design of inhibitors for VarTMPK. Docking and molecular dynamics (MD) studies of the interactions of these compounds inside VarTMPK and human TMPK (HssTMPK) suggest that they compete for the binding region of the substrate and were used to propose the structures of ten new inhibitors for VarTMPK. Further docking and MD simulations of these compounds, inside VarTMPK and HssTMPK, suggest that nine among ten are potential selective inhibitors of VarTMPK. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

A new framework for comprehensive, robust, and efficient global sensitivity analysis: 2. Application

NASA Astrophysics Data System (ADS)

Razavi, Saman; Gupta, Hoshin V.

2016-01-01

Based on the theoretical framework for sensitivity analysis called "Variogram Analysis of Response Surfaces" (VARS), developed in the companion paper, we develop and implement a practical "star-based" sampling strategy (called STAR-VARS), for the application of VARS to real-world problems. We also develop a bootstrap approach to provide confidence level estimates for the VARS sensitivity metrics and to evaluate the reliability of inferred factor rankings. The effectiveness, efficiency, and robustness of STAR-VARS are demonstrated via two real-data hydrological case studies (a 5-parameter conceptual rainfall-runoff model and a 45-parameter land surface scheme hydrology model), and a comparison with the "derivative-based" Morris and "variance-based" Sobol approaches are provided. Our results show that STAR-VARS provides reliable and stable assessments of "global" sensitivity across the full range of scales in the factor space, while being 1-2 orders of magnitude more efficient than the Morris or Sobol approaches.

Sex differences in attenuation of nicotine reinstatement after individual and combined treatments of progesterone and varenicline.

PubMed

Swalve, Natashia; Smethells, John R; Carroll, Marilyn E

2016-07-15

Tobacco use is the largest cause of preventable mortality in the western world. Even after treatment, relapse rates for tobacco are high, and more effective pharmacological treatments are needed. Progesterone (PRO), a female hormone used in contraceptives, reduces stimulant use but its effects on tobacco addiction are unknown. Varenicline (VAR) is a commonly used medication that reduces tobacco use. The present study examined sex differences in the individual vs. combined effects of PRO and VAR on reinstatement of nicotine-seeking behavior in a rat model of relapse. Adult female and male Wistar rats self-administered nicotine (NIC, 0.03mg/kg/infusion) for 14days followed by 21days of extinction when no cues or drug were present. Rats were then divided into 4 treatment groups: control (VEH+SAL), PRO alone (PRO+SAL), VAR alone (VEH+VAR) and the combination (PRO+VAR). Reinstatement of nicotine-seeking behavior induced by priming injections of NIC or caffeine (CAF), presentation of cues (CUES), and the combination of drugs and cues (e.g. NIC+CUES, CAF+CUES) were tested after extinction. Male and female rats did not differ in self-administration of nicotine or extinction responding, and both showed elevated levels of responding to the CAF+CUES condition. However, males, but not females, reinstated active lever-pressing to the NIC+CUES condition, and that was attenuated by both VAR and VAR+PRO treatment. Thus, males were more sensitive to NIC+CUE-induced reinstatement than females, and VAR alone and VAR combined with PRO effectively reduced nicotine relapse. Copyright © 2016 Elsevier B.V. All rights reserved.

JIL-1 and Su(var)3-7 Interact Genetically and Counteract Each Other's Effect on Position-Effect Variegation in Drosophila

PubMed Central

Deng, Huai; Cai, Weili; Wang, Chao; Lerach, Stephanie; Delattre, Marion; Girton, Jack; Johansen, Jørgen; Johansen, Kristen M.

2010-01-01

The essential JIL-1 histone H3S10 kinase is a key regulator of chromatin structure that functions to maintain euchromatic domains while counteracting heterochromatization and gene silencing. In the absence of the JIL-1 kinase, two of the major heterochromatin markers H3K9me2 and HP1a spread in tandem to ectopic locations on the chromosome arms. Here we address the role of the third major heterochromatin component, the zinc-finger protein Su(var)3-7. We show that the lethality but not the chromosome morphology defects associated with the null JIL-1 phenotype to a large degree can be rescued by reducing the dose of the Su(var)3-7 gene and that Su(var)3-7 and JIL-1 loss-of-function mutations have an antagonistic and counterbalancing effect on position-effect variegation (PEV). Furthermore, we show that in the absence of JIL-1 kinase activity, Su(var)3-7 gets redistributed and upregulated on the chromosome arms. Reducing the dose of the Su(var)3-7 gene dramatically decreases this redistribution; however, the spreading of H3K9me2 to the chromosome arms was unaffected, strongly indicating that ectopic Su(var)3-9 activity is not a direct cause of lethality. These observations suggest a model where Su(var)3-7 functions as an effector downstream of Su(var)3-9 and H3K9 dimethylation in heterochromatic spreading and gene silencing that is normally counteracted by JIL-1 kinase activity. PMID:20457875

Burkitt lymphoma expresses oncofetal chondroitin sulfate without being a reservoir for placental malaria sequestration.

PubMed

Agerbaek, Mette Ø; Pereira, Marina A; Clausen, Thomas M; Pehrson, Caroline; Oo, Htoo Zarni; Spliid, Charlotte; Rich, Jamie R; Fung, Vincent; Nkrumah, Francis; Neequaye, Janet; Biggar, Robert J; Reynolds, Steven J; Tosato, Giovanna; Pullarkat, Sheeja T; Ayers, Leona W; Theander, Thor G; Daugaard, Mads; Bhatia, Kishor; Nielsen, Morten A; Mbulaiteye, Sam M; Salanti, Ali

2017-04-01

Burkitt lymphoma (BL) is a malignant disease, which is frequently found in areas with holoendemic Plasmodium falciparum malaria. We have previously found that the VAR2CSA protein is present on malaria-infected erythrocytes and facilitates a highly specific binding to the placenta. ofCS is absent in other non-malignant tissues and thus VAR2CSA generally facilitates parasite sequestration and accumulation in pregnant women. In this study, we show that the specific receptor for VAR2CSA, the oncofetal chondroitin sulfate (ofCS), is likewise present in BL tissue and cell lines. We therefore explored whether ofCS in BL could act as anchor site for VAR2CSA-expressing infected erythrocytes. In contrast to the placenta, we found no evidence of in vivo sequestering of infected erythrocytes in the BL tissue. Furthermore, we found VAR2CSA-specific antibody titers in children with endemic BL to be lower than in control children from the same malaria endemic region. The abundant presence of ofCS in BL tissue and the absence of ofCS in non-malignant tissue encouraged us to examine whether recombinant VAR2CSA could be used to target BL. We confirmed the binding of VAR2CSA to BL-derived cells and showed that a VAR2CSA drug conjugate efficiently killed the BL-derived cell lines in vitro. These results identify ofCS as a novel therapeutic BL target and highlight how VAR2CSA could be used as a tool for the discovery of novel approaches for directing BL therapy. © 2016 UICC.

Burkitt lymphoma express oncofetal Chondroitin Sulfate without being a reservoir for placental malaria sequestration

PubMed Central

Agerbæk, Mette Ø.; Pereira, Marina A.; Clausen, Thomas M.; Pehrson, Caroline; Oo, Htoo Zarni; Spliid, Charlotte; Rich, Jamie R.; Fung, Vincent; Nkrumah, Francis; Neequaye, Janet; Biggar, Robert J.; Reynolds, Steven J.; Tosato, Giovanna; Pullarkat, Sheeja T.; Ayers, Leona W.; Theander, Thor G.; Daugaard, Mads; Bhatia, Kishor; Nielsen, Morten A.; Mbulaiteye, Sam M.; Salanti, Ali

2016-01-01

Burkitt lymphoma (BL) is a malignant disease, which is frequently found in areas with holoendemic Plasmodium falciparum malaria. We have previously found that the VAR2CSA protein is present on malaria-infected erythrocytes and facilitates a highly specific binding to the placenta. OfCS is absent from other non-malignant tissues and thus VAR2CSA generally facilitates parasite sequestration and accumulation in pregnant women. In this study, we show that the specific receptor for VAR2CSA, the oncofetal chondroitin sulfate (ofCS), is likewise present in BL tissue and cell lines. We therefore explored whether ofCS in BL could act as anchor-site for VAR2CSA-expressing infected erythrocytes. In contrast to the placenta, we found no evidence of in vivo sequestering of infected erythrocytes in the BL tissue. Furthermore, we found VAR2CSA specific antibody titers in children with endemic BL to be lower than in control children from the same malaria endemic region. The abundant presence of ofCS in BL tissue and the absence of ofCS in non-malignant tissue, encouraged us to examine whether recombinant VAR2CSA could be used to target BL. We confirmed the binding of VAR2CSA to BL-derived cells and showed that a VAR2CSA drug conjugate efficiently killed the BL-derived cell lines in vitro. These results identify ofCS as a novel therapeutic BL target and highlight how VAR2CSA could be used as a tool for the discovery of novel approaches for directing BL therapy. PMID:27997697

Health and economic consequences of different options for timing the coordinated global cessation of the three oral poliovirus vaccine serotypes.

PubMed

Thompson, Kimberly M; Duintjer Tebbens, Radboud J

2015-09-17

World leaders remain committed to globally-coordinated oral poliovirus vaccine (OPV) cessation following successful eradication of wild polioviruses, but the best timing and strategy for implementation depend on existing and emerging conditions. Using an existing integrated global poliovirus risk management model, we explore alternatives to the current timing plan of coordinated cessation of each OPV serotype (i.e., OPV1, OPV2, and OPV3 cessation for serotypes 1, 2, and 3, respectively). We assume the current timing plan involves OPV2 cessation in 2016 followed by OPV1 and OPV3 cessation in 2019 and we compare this to alternative timing options, including cessation of all three serotypes in 2018 or 2019, and cessation of both OPV2 and OPV3 in 2017 followed by OPV1 in 2019. If Supplemtal Immunization Activity frequency remains sufficiently high through cessation of the last OPV serotype, then all OPV cessation timing options prevent circulating vaccine-derived poliovirus (cVDPV) outbreaks after OPV cessation of any serotype. The various OPV cessation timing options result in relatively modest differences in expected vaccine-associated paralytic poliomyelitis cases and expected total of approximately 10-13 billion polio vaccine doses used. However, the expected amounts of vaccine of different OPV formulations needed changes dramatically with each OPV cessation timing option. Overall health economic impacts remain limited for timing options that only change the OPV formulation but preserve the currently planned year for cessation of the last OPV serotype and the global introduction of inactivated poliovirus vaccine (IPV) introduction. Earlier cessation of the last OPV serotype or later global IPV introduction yield approximately $1 billion in incremental net benefits due to saved vaccination costs, although the logistics of implementation of OPV cessation remain uncertain and challenging. All countries should maintain the highest possible levels of population immunity to transmission for each poliovirus serotype prior to the coordinated cessation of the OPV serotype to manage cVDPV risks. If OPV2 cessation gets delayed, then global health leaders should consider other OPV cessation timing options.

Sero-Prevalence and Genetic Diversity of Pandemic V. parahaemolyticus Strains Occurring at a Global Scale.

PubMed

Han, Chongxu; Tang, Hui; Ren, Chuanli; Zhu, Xiaoping; Han, Dongsheng

2016-01-01

Pandemic Vibrio parahaemolyticus is an emerging public health concern as it has caused numerous gastroenteritis outbreaks worldwide. Currently, the absence of a global overview of the phenotypic and molecular characteristics of pandemic strains restricts our overall understanding of these strains, especially for environmental strains. To generate a global picture of the sero-prevalence and genetic diversity of pandemic V. parahaemolyticus, pandemic isolates from worldwide collections were selected and analyzed in this study. After a thorough analysis, we found that the pandemic isolates represented 49 serotypes, which are widely distributed in 22 countries across four continents (Asia, Europe, America and Africa). All of these serotypes were detected in clinical isolates but only nine in environmental isolates. O3:K6 was the most widely disseminated serotype, followed by O3:KUT, while the others were largely restricted to certain countries. The countries with the most abundant pandemic serotypes were China (26 serotypes), India (24 serotypes), Thailand (15 serotypes) and Vietnam (10 serotypes). Based on MLST analysis, 14 sequence types (STs) were identified among the pandemic strains, nine of which fell within clonal complex (CC) 3. ST3 and ST305 were the only two STs that have been reported in environmental pandemic strains. Pandemic ST3 has caused a wide range of infections in as many as 16 countries. Substantial serotypic diversity was mainly observed among isolates within pandemic ST3, including as many as 12 combinations of O/K serotypes. At the allele level, the dtdS and pntA, two loci that perfectly conserved in CC3, displayed a degree of polymorphism in some pandemic strains. In conclusion, we provide a comprehensive understanding of sero-prevalence and genetic differentiation of clinical and environmental pandemic isolates collected from around the world. Although, further studies are needed to delineate the specific mechanisms by which the pandemic strains evolve and spread, the findings in this study are helpful when seeking countermeasures to reduce the spread of V. parahaemolyticus in endemic areas.

Listeria monocytogenes serotype 1/2b and 4b isolates from human clinical cases and foods show differences in tolerance to refrigeration and salt stress.

PubMed

Ribeiro, V B; Destro, M T

2014-09-01

Control of Listeria monocytogenes in food processing facilities is a difficult issue because of the ability of this microorganism to form biofilms and adapt to adverse environmental conditions. Survival at high concentrations of sodium chloride and growth at refrigeration temperatures are two other important characteristics of L. monocytogenes isolates. The aim of this study was to compare the growth characteristics under stress conditions at different temperatures of L. monocytogenes serotypes responsible for the majority of clinical cases from different sources. Twenty-two L. monocytogenes isolates, 12 from clinical cases (8 serotype 4b and 4 serotype 1/2a) and 10 from food (6 serotype 4b and 4 serotype 1/2a), and an L. monocytogenes Scott A (serotype 4b) reference strain were analyzed for the ability to grow in brain heart infusion broth plus 1.9 M NaCl (11%) at 4, 10, and 25°C for 73, 42, and 15 days, respectively. The majority of L. monocytogenes strains was viable or even grew at 4°C and under the high osmotic conditions usually used to control pathogens in the food industry. At 10°C, most strains could adapt and grow; however, no significant difference (P > 0.05) was found for lag-phase duration, maximum growth rate, and maximum cell density. At 25°C, all strains were able to grow, and populations increased by up 5 log CFU/ml. Clinical strains had a significantly longer lag phase and lower maximum cell density (P < 0.05) than did food strains. Regarding virulence potential, no significant differences in hemolytic activity were found among serotypes; however, serotype 4b strains were more invasive in Caco-2 cells than were serotype 1/2a strains (P < 0.05). The global tendency of decreasing NaCl concentrations in processed foods for health reasons may facilitate L. monocytogenes survival and growth in these products. Therefore, food companies must consider additional microbial growth barriers to assure product safety.

Direct Comparison of Immunogenicity Induced by 10- or 13-Valent Pneumococcal Conjugate Vaccine around the 11-Month Booster in Dutch Infants.

PubMed

Wijmenga-Monsuur, Alienke J; van Westen, Els; Knol, Mirjam J; Jongerius, Riet M C; Zancolli, Marta; Goldblatt, David; van Gageldonk, Pieter G M; Tcherniaeva, Irina; Berbers, Guy A M; Rots, Nynke Y

2015-01-01

Since 2009/10, a 10- and a 13-valent pneumococcal conjugate vaccine (PCV) are available, but only the 10-valent vaccine is now being used for the children in the Netherlands. As the vaccines differ in number of serotypes, antigen concentration, and carrier proteins this study was designed to directly compare quantity and quality of the antibody responses induced by PCV10 and PCV13 before and after the 11-month booster. Dutch infants (n = 132) were immunized with either PCV10 or PCV13 and DTaP-IPV-Hib-HepB at the age of 2, 3, 4 and 11 months. Blood samples were collected pre-booster and post-booster at one week and one month post-booster for quantitative and qualitative immunogenicity against 13 pneumococcal serotypes, as well as quantitative immunogenicity against diphtheria, tetanus, pertussis and Haemophilus influenzae type b. We compared immunogenicity induced by PCV13 and PCV10 for their ten shared serotypes. One month post-booster, pneumococcal serotype-specific IgG geometric mean concentrations (GMCs) for the PCV13 group were higher compared with the PCV10 group for six serotypes, although avidity was lower. Serotype 19F showed the most distinct difference in IgG and, in contrast to other serotypes, its avidity was higher in the PCV13 group. One week post-booster, opsonophagocytosis for serotype 19F did not differ significantly between the PCV10- and the PCV13 group. Both PCV10 and PCV13 were immunogenic and induced a booster response. Compared to the PCV10 group, the PCV13 group showed higher levels for serotype 19F GMCs and avidity, pre- as well as post-booster, although opsonophagocytosis did not differ significantly between groups. In our study, avidity is not correlated to opsonophagocytotic activity (OPA) and correlations between IgG and OPA differ per serotype. Therefore, besides assays to determine IgG GMCs, assays to detect opsonophagocytotic activity, i.e., the actual killing of the pneumococcus, are important for PCV evaluation. How differences between the two vaccines relate to long-term protection requires further investigation. www.trialregister.nl NTR3069.

Simultaneous detection and serotyping of dengue infection using single tube multiplex CDC Dengue Real-Time RT-PCR from India.

PubMed

Sharma, Shashi; Tandel, Kundan; Danwe, Surabhi; Bhatt, Puneet; Dash, P K; Ranjan, Praveer; Rathi, K R; Gupta, Rajiv Mohan; Parida, M M

2018-03-01

Four antigenically different dengue virus serotypes (DENV-1, DENV-2, DENV-3 and DENV-4) are known to cause infections in humans. Some of these are known to cause more severe disease than the others. Chances for developing Dengue hemorrhagic fever-dengue shock syndrome (DHF-DSS) increases significantly with history of previous infection with one of the four serotypes. Therefore, early diagnosis, serotyping and providing early warning of dengue fever epidemics to concerned authorities becomes very important for better patient outcome and to curb the rapid spread in the community. During the 2014 outbreak, a total of 100 samples from suspected cases of dengue were collected. NS1 antigen based rapid test was used for serological diagnosis. Dengue complex one step reverse transcription-polymerase chain reaction was performed to look for presence of viral RNA. Single tube multiplex RT-PCR was also performed to look for infecting serotype. CDC Dengue Multiplex Real Time PCR assay was performed for rapid diagnosis and simultaneous serotyping of the dengue virus. Out of the 100 samples screened, 69 were found to be positive by NS1Ag Rapid test. 34 samples were found positive by dengue consensus RT-PCR assay. 22 samples were found to be positive by single tube Dengue multiplex RT-PCR assay. Serotype DEN-2 was present in maximum numbers followed by DEN-3. 44 samples were found positive by DENV CDC Multiplex Real time PCR assay. DEN-2 was found in maximum numbers followed by DEN-1. Dengue remains to be an important health problem in India and across the globe. Few serotypes of dengue are more dangerous than the others. Rapid diagnosis and serotyping remains the key for better patient management and prevention of disease spreading in the community. Highly sensitive, specific and rapid CDC real time RT-PCR assay was found to be most promising tool among all available molecular diagnostic methods. This will serve a rapid and reliable simultaneous dengue virus detection as well serotyping assay in near future for rapid identification of dengue suspected sample screening.

Non-invasive pneumococcal serotypes and antimicrobial susceptibilities in a paediatric hospital in the era of conjugate vaccines.

PubMed

McElligott, Martha; Vickers, Imelda; Cafferkey, Mary; Cunney, Robert; Humphreys, Hilary

2014-06-12

To evaluate the effects of 7-valent pneumococcal conjugate vaccine (PCV7) introduction to the routine childhood immunisation schedule in 2008 and its replacement by PCV13 in 2010 in Ireland, we surveyed the serotypes and antimicrobial susceptibilities of 339 pneumococci associated with carriage and non-invasive infection (NII) in a Dublin paediatric hospital from 2009 to 2012. Furthermore, we compared the distribution of pneumococcal serotypes collected from 2009 to 2012 to 105 NII pneumococci isolated in 2007, the year before conjugate vaccine introduction. PCV7 serotypes declined from 2007 to 2012 as follows: carriage, 67-23% (p=0.0004); conjunctivitis, 58-0% (p<0.0001); non-bacteraemic lower respiratory tract infection, 50-19% (p=0.0363) and otitis media 54-27%. Notably, antimicrobial resistant (AMR) PCV7 serotypes showed a significant decrease by the end of the study period (i.e. 2012) (p<0.0001). Compared with 2007 the overall occurrence of serotype 19A increased from 1.9 to 10% in 2010 (p=0.0132) and to 15% in 2011 (p=0.0005). Importantly, serotype 19A declined significantly from 2011 levels to an overall prevalence of 4.8% in 2012 (p=0.0243). Most striking was the significant reduction of AMR 19A (p=0.0195). Conversely, increases were observed in non-vaccine type (NVT) pneumococci in 2009-2012, of which serotypes 11A (n=30), 15B/C (n=17), 22F (n=14), 35Bn=13), non-typeable pneumococci (n=13) and 23A (n=12) were the most prevalent. Moreover, an increase in NVT non-susceptible to at least one antimicrobial in 2009-2012 was noted, attributable to serotypes 35B (n=10) and 15A (n=7). In summary, this study has shown that PCV7 and PCV13 introduction has had a positive impact on their target serotypes and antimicrobial resistance amongst pneumococci within a paediatric hospital within a short time period. However, the increase in NVT prevalence highlights the need for continued surveillance. Copyright © 2014 Elsevier Ltd. All rights reserved.

An adenovirus prime/plasmid boost strategy for induction of equipotent immune responses to two dengue virus serotypes.

PubMed

Khanam, Saima; Rajendra, Pilankatta; Khanna, Navin; Swaminathan, Sathyamangalam

2007-02-15

Dengue is a public health problem of global significance for which there is neither an effective antiviral therapy nor a preventive vaccine. It is a mosquito-borne viral disease, caused by dengue (DEN) viruses, which are members of the Flaviviridae family. There are four closely related serotypes, DEN-1, DEN-2, DEN-3 and DEN-4, each of which is capable of causing disease. As immunity to any one serotype can potentially sensitize an individual to severe disease during exposure to a heterologous serotype, the general consensus is that an effective vaccine should be tetravalent, that is, it must be capable of affording protection against all four serotypes. The current strategy of creating tetravalent vaccine formulations by mixing together four monovalent live attenuated vaccine viruses has revealed the phenomenon of viral interference leading to the manifestation of immune responses biased towards a single serotype. This work stems from the emergence of (i) the DEN virus envelope (E) domain III (EDIII) as the most important region of the molecule from a vaccine perspective and (ii) the adenovirus (Ad) as a promising vaccine vector platform. We describe the construction of a recombinant, replication-defective Ad (rAd) vector encoding a chimeric antigen made of in-frame linked EDIIIs of DEN virus serotypes 2 and 4. Using this rAd vector, in conjunction with a plasmid vector encoding the same chimeric bivalent antigen, in a prime-boost strategy, we show that it is possible to elicit equipotent neutralizing and T cell responses specific to both DEN serotypes 2 and 4. Our data support the hypothesis that a DEN vaccine targeting more than one serotype may be based on a single DNA-based vector to circumvent viral interference. This work lays the foundation for developing a single Ad vector encoding EDIIIs of all four DEN serotypes to evoke a balanced immune response against each one of them. Thus, this work has implications for the development of safe and effective tetravalent dengue vaccines.

Bordetella pertussis isolates in Finland: Serotype and fimbrial expression

PubMed Central

Heikkinen, Eriikka; Xing, Dorothy K; Ölander, Rose-Marie; Hytönen, Jukka; Viljanen, Matti K; Mertsola, Jussi; He, Qiushui

2008-01-01

Background Bordetella pertussis causes whooping cough or pertussis in humans. It produces several virulence factors, of which the fimbriae are considered adhesins and elicit immune responses in the host. B. pertussis has three distinct serotypes Fim2, Fim3 or Fim2,3. Generally, B. pertussis Fim2 strains predominate in unvaccinated populations, whereas Fim3 strains are often isolated in vaccinated populations. In Finland, pertussis vaccination was introduced in 1952. The whole-cell vaccine contained two strains, 18530 (Fim3) since 1962 and strain 1772 (Fim2,3) added in 1976. After that the vaccine has remained the same until 2005 when the whole-cell vaccine was replaced by the acellular vaccine containing pertussis toxin and filamentous hemagglutinin. Our aims were to study serotypes of Finnish B. pertussis isolates from 1974 to 2006 in a population with > 90% vaccination coverage and fimbrial expression of the isolates during infection. Serotyping was done by agglutination and serotype-specific antibody responses were determined by blocking ELISA. Results Altogether, 1,109 isolates were serotyped. Before 1976, serotype distributions of Fim2, Fim3 and Fim2,3 were 67%, 19% and 10%, respectively. From 1976 to 1998, 94% of the isolates were Fim2 serotype. Since 1999, the frequency of Fim3 strains started to increase and reached 83% during a nationwide epidemic in 2003. A significant increase in level of serum IgG antibodies against purified fimbriae was observed between paired sera of 37 patients. The patients infected by Fim3 strains had antibodies which blocked the binding of monoclonal antibodies to Fim3 but not to Fim2. Moreover, about one third of the Fim2 strain infected patients developed antibodies capable of blocking of binding of both anti-Fim2 and Fim3 monoclonal antibodies. Conclusion Despite extensive vaccinations in Finland, B. pertussis Fim2 strains were the most common serotype. Emergence of Fim3 strains started in 1999 and coincided with nationwide epidemics. Results of serotype-specific antibody responses suggest that Fim2 strains could express Fim3 during infection, showing a difference in fimbrial expression between in vivo and in vitro. PMID:18816412

A Novel Virus-Like Particle Based Vaccine Platform Displaying the Placental Malaria Antigen VAR2CSA.

PubMed

Thrane, Susan; Janitzek, Christoph M; Agerbæk, Mette Ø; Ditlev, Sisse B; Resende, Mafalda; Nielsen, Morten A; Theander, Thor G; Salanti, Ali; Sander, Adam F

2015-01-01

Placental malaria caused by Plasmodium falciparum is a major cause of mortality and severe morbidity. Clinical testing of a soluble protein-based vaccine containing the parasite ligand, VAR2CSA, has been initiated. VAR2CSA binds to the human receptor chondroitin sulphate A (CSA) and is responsible for sequestration of Plasmodium falciparum infected erythrocytes in the placenta. It is imperative that a vaccine against malaria in pregnancy, if administered to women before they become pregnant, can induce a strong and long lasting immune response. While most soluble protein-based vaccines have failed during clinical testing, virus-like particle (VLP) based vaccines (e.g., the licensed human papillomavirus vaccines) have demonstrated high efficacy, suggesting that the spatial assembly of the vaccine antigen is a critical parameter for inducing an optimal long-lasting protective immune response. We have developed a VLP vaccine display platform by identifying regions of the HPV16 L1 coat protein where a biotin acceptor site (AviTagTM) can be inserted without compromising VLP-assembly. Subsequent biotinylation of Avi-L1 VLPs allow us to anchor monovalent streptavidin (mSA)-fused proteins to the biotin, thereby obtaining a dense and repetitive VLP-display of the vaccine antigen. The mSA-VAR2CSA antigen was delivered on the Avi-L1 VLP platform and tested in C57BL/6 mice in comparison to two soluble protein-based vaccines consisting of naked VAR2CSA and mSA-VAR2CSA. The mSA-VAR2CSA Avi-L1 VLP and soluble mSA-VAR2CSA vaccines induced higher antibody titers than the soluble naked VAR2CSA vaccine after three immunizations. The VAR2CSA Avi-L1 VLP vaccine induced statistically significantly higher endpoint titres compared to the soluble mSA-VAR2CSA vaccine, after 1st and 2nd immunization; however, this difference was not statistically significant after 3rd immunization. Importantly, the VLP-VAR2CSA induced antibodies were functional in inhibiting the binding of parasites to CSA. This study demonstrates that the described Avi-L1 VLP-platform may serve as a versatile system for facilitating optimal VLP-display of large and complex vaccine antigens.

Dominance of serotype Ia among group B Streptococci causing invasive infections in nonpregnant adults in Portugal.

PubMed

Martins, E R; Melo-Cristino, J; Ramirez, M

2012-04-01

The population of group B streptococci (GBS) associated with invasive infections in nonpregnant adults from 2001 to 2008 was analyzed in isolates submitted from 24 hospital laboratories in Portugal (n = 225). The isolates were characterized by antimicrobial susceptibility, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and surface protein gene profiling. GBS invasive cases were found more frequently among men in all age groups. In addition, serotype Ia was the most frequent in our collection, whereas serotype V is dominant elsewhere. Serotype Ia was represented mainly by a single PFGE cluster defined by sequence type 23 (ST23) and surface protein gene eps and by ST24 and bca, similarly to neonatal invasive infections in Portugal, indicating that the same genetic lineages can be responsible for both vaginal colonization and invasive disease in all age groups. In contrast, the hypervirulent serotype III/ST17 neonatal lineage was responsible for a minority of infections. Serotype V isolates were distributed into two genetic lineages, one defined by ST1 and surface protein gene alp3 and macrolide resistant, and another presenting with ST2 and eps and fully susceptible to all antimicrobials tested. The erm(TR) gene was the most frequently found among erythromycin-resistant isolates, while the bovine-associated tet(O) gene was found in a minority of tetracycline-resistant isolates. Our data emphasize the importance of local identification of the genetic lineages responsible for GBS invasive infections in nonpregnant adults. The dominance of serotype Ia in invasive disease in Portugal highlights the importance of this serotype in GBS pathogenesis.

Phenotypes, serotypes and antibiotic susceptibility of Swedish Porphyromonas gingivalis isolates from periodontitis and periodontal abscesses.

PubMed

Dahlén, G; Gmür, R; Yoshino, T

2007-04-01

This study was conducted to reveal phenotypic, serological subtypes and antibiotic susceptibility among fresh isolates of Porphyromonas gingivalis in a Swedish population with periodontitis and periodontal abscess. Fifty-five subgingival strains were isolated and tentatively designated as P. gingivalis from 55 consecutive paper-point samples taken from 51 patients with periodontitis (at least one site with >6-mm pocket depth) in Sweden and were sent in for microbiological evaluation. Eight P. gingivalis strains from periodontal abscesses were also included. Four P. gingivalis strains served as reference and another four type strains were included. The strains were characterized by colony morphology, biochemical tests, enzyme profile, gas-liquid chromatography and antibiotic susceptibility. The strains were further characterized for whole cell protein profiles using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and were identified to serotype by specific monoclonal antibodies. Among the 55 P. gingivalis strains 35 had smooth (S), 13 rough (R) and seven semi-rough colony morphologies. All strains were phenotypically homogeneous in biochemical tests, enzyme profile and antibiotic susceptibility. All strains produced phenylacetic acid and alpha-fucosidase. Almost all (96%) of the subgingival strains, but relatively fewer (62%) of the abscess strains, belonged to serotype A. Two subgingival and three abscess strains were classified as serotype B. No specific SDS-PAGE protein profiles were recorded for the two serotypes. The P. gingivalis strains from Swedish periodontitis cases showed homogeneity in terms of biochemical phenotypes and antibiotic susceptibility patterns. The strains fell into two serotypes, of which serotype A predominated in the periodontitis cases and serotype B was overrepresented in periodontal abscesses.

Diversity of O Antigens within the Genus Cronobacter: from Disorder to Order

PubMed Central

Javůrková, Barbora; Vlach, Jiří; Göselová, Sandra; Karamonová, Ludmila; Ogrodzki, Pauline; Forsythe, Stephen; Fukal, Ladislav

2015-01-01

Cronobacter species are Gram-negative opportunistic pathogens that can cause serious infections in neonates. The lipopolysaccharides (LPSs) that form part of the outer membrane of such bacteria are possibly related to the virulence of particular bacterial strains. However, currently there is no clear overview of O-antigen diversity within the various Cronobacter strains and links with virulence. In this study, we tested a total of 82 strains, covering each of the Cronobacter species. The nucleotide variability of the O-antigen gene cluster was determined by restriction fragment length polymorphism (RFLP) analysis. As a result, the 82 strains were distributed into 11 previously published serotypes and 6 new serotypes, each defined by its characteristic restriction profile. These new serotypes were confirmed using genomic analysis of strains available in public databases: GenBank and PubMLST Cronobacter. Laboratory strains were then tested using the current serotype-specific PCR probes. The results show that the current PCR probes did not always correspond to genomic O-antigen gene cluster variation. In addition, we analyzed the LPS phenotype of the reference strains of all distinguishable serotypes. The identified serotypes were compared with data from the literature and the MLST database (www.pubmlst.org/cronobacter/). Based on the findings, we systematically classified a total of 24 serotypes for the Cronobacter genus. Moreover, we evaluated the clinical history of these strains and show that Cronobacter sakazakii O2, O1, and O4, C. turicensis O1, and C. malonaticus O2 serotypes are particularly predominant in clinical cases. PMID:26070668

Genetic Diversity of Clinical and Environmental Strains of Salmonella enterica Serotype Weltevreden Isolated in Malaysia

PubMed Central

Thong, K. L.; Goh, Y. L.; Radu, S.; Noorzaleha, S.; Yasin, R.; Koh, Y. T.; Lim, V. K. E.; Rusul, G.; Puthucheary, S. D.

2002-01-01

The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia. PMID:12089269

Genetic diversity of clinical and environmental strains of Salmonella enterica serotype Weltevreden isolated in Malaysia.

PubMed

Thong, K L; Goh, Y L; Radu, S; Noorzaleha, S; Yasin, R; Koh, Y T; Lim, V K E; Rusul, G; Puthucheary, S D

2002-07-01

The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia.

Prevalence of Listeria monocytogenes in retailed meat in the Tokyo metropolitan area.

PubMed

Ochiai, Yoshitsugu; Yamada, Fumiya; Batmunkh, Otgonchimeg; Mochizuki, Mariko; Takano, Takashi; Hondo, Ryo; Ueda, Fukiko

2010-09-01

This study was conducted to determine the prevalence of Listeria monocytogenes in retailed meats, comprising beef, chicken, and pork, in the Tokyo metropolitan area. A total of 379 samples of retailed meat were collected from 1998 to 2003, most of which were obtained by simultaneously purchasing the three classes of meat from a shop and then making another simultaneous purchase of meat from the same shop a few weeks later. The prevalence of L. monocytogenes was 28.0%, and the serotypes isolated were mainly 1/2a, 1/2b, 1/2c, and 4b. Comparison of the prevalence of each serotype among the classes of meat showed a predominant distribution of serotypes 1/2a, 1/2b, and 4b in chicken, while serotype 1/2c was dominant in pork. A total of nine cases considered to be due to persistence and/or cross-contamination were found. Most of the strains involved in persistence and/or cross-contamination were of serotypes 1/2c or 4b. These results suggest that contamination in retailed meat in Japan is at almost the same level as in other countries and that chicken has the highest potential as a source of contamination and infection. In addition, we suggest that the ecological niche of serotype 1/2c is distinct from those of 1/2a, 1/2b, and 4b, which may explain why human hosts have less opportunity to be exposed to serotype 1/2c and why there is a lower rate of isolation of this serotype from cases of human listeriosis.

Development and application of novel SNP-based serotyping assays in targeting Salmonella enterica within the poultry production and processing continuum.

USDA-ARS?s Scientific Manuscript database

Salmonella enterica subsp. enterica serotype Enteriditis (S. Enteriditis) is the leading cause of salmonellosis worldwide. While some S. enterica serotypes are specific to birds, many represent human zoonotic pathogens, thus their presence and survival throughout the continuum of poultry production...

Complete nucleotide sequences of three pigeon paramyxovirus serotype-1 (PPMV-1) isolates

USDA-ARS?s Scientific Manuscript database

Pigeon paramyxovirus serotype-1 (PPMV-1) is an antigenic variant of avian paramyxovirus serotype-1 (APMV-1), the agent responsible for Newcastle disease. Given that PPMV-1 can be transmitted to the poultry population it is important to characterize PPMV-1 in native birds. Here we report the complet...

Streptococcus agalactiae serotype Ib as an agent of meningitis in two adult nonpregnant women.

PubMed

Martins, E R; Florindo, C; Martins, F; Aldir, I; Borrego, M J; Brum, L; Ramirez, M; Melo-Cristino, J

2007-11-01

Two temporally and geographically clustered cases of meningitis caused by Streptococcus agalactiae expressing the infrequent Ib serotype are reported. Characterization by pulsed-field gel electrophoresis and multilocus sequence typing revealed that the isolates were identical and represented the widely distributed ST10/ST8 lineage associated with serotype Ib.

Experimental infection of white-tailed deer (Odocoileus virginianus) with Northern European bluetongue virus serotype 8

USDA-ARS?s Scientific Manuscript database

Bluetongue (BT) is an insect-transmitted, economically important disease of domestic and wild ruminants. Although only five of the 26 reported bluetongue virus (BTV) serotypes are considered endemic to the USA, 10 exotic serotypes have been isolated primarily in the southeastern region of the count...

Intergenic Sequence Ribotyping using a region neighboring dkgB links genovar to Kauffman-White serotype of Salmonella enterica

USDA-ARS?s Scientific Manuscript database

Previous research identified that the 5S ribosomal (rrn) gene and associated flanking sequences that are closely linked to the dkgB gene of Salmonella enterica were highly variable between serotypes, but not between subpopulations within the same serotype (PMID: 17005008). The degree of variability ...

Determination of the median lethal dose of botulinum serotype E in channel catfish fingerlings

USDA-ARS?s Scientific Manuscript database

The median lethal dose of botulinum serotype E in 5.3-g channel catfish Ictalurus punctatus fingerlings was determined. Five tanks (five fish/tank) were assigned to each of the following treatment groups: 70, 50, 35, 25, or 15 pg of purified botulinum serotype E. Fish were injected intracoelomically...

Susceptibility of North American white-tailed deer to the Netherlands strain of BTV serotype 8

USDA-ARS?s Scientific Manuscript database

World-wide there are at least 24 serotypes of bluetongue virus (BTV), a complex non-enveloped virus in the family Reoviridae, genus Orbivirus. Bluetongue (BT) is an arthropod-borne disease of cattle, sheep, goats, and deer and is transmitted by Culicoides biting midges. In 2006, bluetongue serotype ...

Biofilm formation of non-O157 Shiga toxin-producing Escherichia coli (STEC) on equipment surfaces

USDA-ARS?s Scientific Manuscript database

Introduction: Shiga toxin-producing Escherichia coli (STEC) serotype O157:H7 has been the most commonly recognized STEC serotype responsible for foodborne outbreaks in the US. Numerous outbreaks associated with non-O157 serotypes have also been reported due to consumption of contaminated food. The ...

A Novel Botulinum Neurotoxin, Previously Reported as Serotype H, Has a Hybrid-Like Structure With Regions of Similarity to the Structures of Serotypes A and F and Is Neutralized With Serotype A Antitoxin

PubMed Central

Maslanka, Susan E.; Lúquez, Carolina; Dykes, Janet K.; Tepp, William H.; Pier, Christina L.; Pellett, Sabine; Raphael, Brian H.; Kalb, Suzanne R.; Barr, John R.; Rao, Agam; Johnson, Eric A.

2016-01-01

Botulism is a potentially fatal paralytic disease caused by the action of botulinum neurotoxin (BoNT) on nerve cells. There are 7 known serotypes (A–G) of BoNT and up to 40 genetic variants. Clostridium botulinum strain IBCA10-7060 was recently reported to produce BoNT serotype B (BoNT/B) and a novel BoNT, designated as BoNT/H. The BoNT gene (bont) sequence of BoNT/H was compared to known bont sequences. Genetic analysis suggested that BoNT/H has a hybrid-like structure containing regions of similarity to the structures of BoNT/A1 and BoNT/F5. This novel BoNT was serologically characterized by the mouse neutralization assay and a neuronal cell–based assay. The toxic effects of this hybrid-like BoNT were completely eliminated by existing serotype A antitoxins, including those contained in multivalent therapeutic antitoxin products that are the mainstay of human botulism treatment. PMID:26068781

Changes in the features of invasive pneumococcal disease after introduction of the seven-valent pneumococcal conjugate vaccine in a regional core hospital of Kochi, Japan.

PubMed

Miyahara, Hiroyuki; Maruyama, Hidehiko; Kanazawa, Akane; Iwasaki, Yuka; Shigemitsu, Yusuke; Watanabe, Hirokazu; Tokorodani, Chiho; Miyazawa, Mari; Nakata, Yusei; Nishiuchi, Ritsuo; Kikkawa, Kiyoshi

2015-01-01

Since the introduction of the seven-valent pneumococcal conjugate vaccine (PCV7) in 2007, invasive pneumococcal disease has declined, but the incidence of Streptococcus pneumoniae serotype 19A has risen worldwide. The present study examined changes in the features of invasive pneumococcal disease since the introduction of the PCV7 in Kochi, Japan. Pediatric cases of invasive pneumococcal disease were investigated before and after vaccine introduction (January 2008 to December 2013). Cases of invasive pneumococcal disease tended to decrease after PCV7 introduction. In addition, before introduction of the vaccine, most serotypes causing invasive pneumococcal disease were those included in the vaccine. However, after the introduction, we found cases infected by serotypes not covered by vaccine. Penicillin-resistant S. pneumoniae was the predominant serotype causing invasive pneumococcal disease before introduction of the PCV7, and the susceptibility of this serotype to antibiotics improved after vaccine introduction. Serotype isolates identified after vaccine introduction were also relatively susceptible to antibiotic therapy, but decreased susceptibility is expected.

Evaluation of the solid phase competition ELISA for detecting antibodies against the six foot-and-mouth disease virus non-O serotypes.

PubMed

Li, Yanmin; Swabey, Kate G; Gibson, Debi; Keel, Phil J; Hamblin, Pip; Wilsden, Ginette; Corteyn, Mandy; Ferris, Nigel P

2012-08-01

The solid-phase competition ELISA (SPCE) has been evaluated in both screening and titration assay formats for detecting antibodies against foot-and-mouth disease virus (FMDV) for the six non-O serotypes A, C, SAT 1, SAT 2, SAT 3 and Asia 1. Cut-off values were determined as a percentage inhibition of 40 for the SAT serotypes and 50 for serotypes A, C and Asia 1, which gave rise to specificity values ranging from 99.41% to 99.9% for the different serotypes. The relative sensitivity between the SPCE and LPBE/virus neutralisation test was 100%/109%. Antiserum titres derived by the SPCE for samples of serotypes O, A(22) and Asia 1 were more than 11, 1 and 5 times of those determined by virus neutralisation test, respectively. This study indicated that the non-type O SPCEs have sufficient sensitivities and specificities for use as serological diagnostic tests for the qualitative and quantitative detection of antibodies against FMDV. Copyright © 2012 Elsevier B.V. All rights reserved.

A novel one-step real-time multiplex PCR assay to detect Streptococcus agalactiae presence and serotypes Ia, Ib, and III.

PubMed

Furfaro, Lucy L; Chang, Barbara J; Payne, Matthew S

2017-09-01

Streptococcus agalactiae is the leading cause of early-onset neonatal sepsis. Culture-based screening methods lack the sensitivity of molecular assays and do not indicate serotype; a potentially important virulence marker. We aimed to develop a multiplex PCR to detect S. agalactiae while simultaneously identifying serotypes Ia, Ib, and III; commonly associated with infant disease. Primers were designed to target S. agalactiae serotype-specific cps genes and the dltS gene. The assay was validated with 512 vaginal specimens from pregnant women. 112 (21.9%) were dltS positive, with 14.3%, 0.9%, and 6.3% of these identified as cps Ia, Ib, and III, respectively. Our assay is a specific and sensitive method to simultaneously detect S. agalactiae and serotypes Ia, Ib, and III in a single step. It is of high significance for clinical diagnostic applications and also provides epidemiological data on serotype, information that may be important for vaccine development and other targeted non-antibiotic therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

Independent segregation of two antigenic specificities (VP3 and VP7) involved in neutralization of rotavirus infectivity.

PubMed Central

Hoshino, Y; Sereno, M M; Midthun, K; Flores, J; Kapikian, A Z; Chanock, R M

1985-01-01

Antiserum prepared against the M37 strain of rotavirus, recovered from an asymptomatic newborn infant in Venezuela, neutralized two prototype human rotaviruses that define two separate serotypes: serotype 1 (Wa) and serotype 4 (ST3). Thus, the M37 strain is a naturally occurring intertypic rotavirus. Analysis of reassortant viruses produced during coinfection in vitro indicated that the observed dual serotype specificity of M37 resulted from sharing a related outer capsid protein, VP3, with the ST3 virus and another related outer capsid protein, VP7, with the Wa virus. Analysis of single (VP3)-gene-substitution reassortants indicated that VP3 was as potent an immunogen as VP7. In addition, direct evidence was obtained that the serotype specificity of neutralizing antibody elicited by VP3 can differ from the serotype specificity of neutralizing antibody elicited by VP7, indicating the need for a dual system of rotavirus classification in which the neutralization specificity of both VP3 and VP7 outer capsid proteins are identified. Images PMID:3001716

Isolation, propagation, and characterization of a second equine rotavirus serotype.

PubMed Central

Hoshino, Y; Wyatt, R G; Greenberg, H B; Kalica, A R; Flores, J; Kapikian, A Z

1983-01-01

A rotavirus designated strain H-2 was isolated in primary African green monkey kidney cells from a foal with diarrhea. This cell culture-adapted strain was found to be similar, if not identical, to simian rotavirus (strains MMU18006 and SA-11) and canine rotavirus (strain CU-1) and, in addition, demonstrated a one-way antigenic relationship with five human rotavirus strains (P, B, no. 14, no. 15, and YO) of the third human rotavirus serotype by the plaque reduction neutralization test. This is the fifth example of an animal rotavirus which shares serotypic specificity with a human rotavirus. The H-2 strain is distinct from the H-1 strain (Y. Hoshino et al., J. Clin. Microbiol., in press) of equine rotavirus not only in serotypic specificity by neutralization but also in subgroup specificity, hemagglutinating activity, and RNA electrophoretic migration pattern, thus establishing the existence of a second equine rotavirus serotype. This H-2 isolate is also distinct by neutralization from three other human rotavirus serotypes, 1 (Wa), 2 (DS-1), and 4 (St. Thomas no. 4), as well as bovine (NCDV), and porcine (OSU) rotaviruses. Images PMID:6309657

Morphological analyses suggest a new taxonomic circumscription for Hymenaea courbaril L. (Leguminosae, Caesalpinioideae)

PubMed Central

Souza, Isys Mascarenhas; Funch, Ligia Silveira; de Queiroz, Luciano Paganucci

2014-01-01

Abstract Hymenaea is a genus of the Resin-producing Clade of the tribe Detarieae (Leguminosae: Caesalpinioideae) with 14 species. Hymenaea courbaril is the most widespread species of the genus, ranging from southern Mexico to southeastern Brazil. As currently circumscribed, Hymenaea courbaril is a polytypic species with six varieties: var. altissima, var. courbaril, var. longifolia, var. stilbocarpa, var. subsessilis, and var. villosa. These varieties are distinguishable mostly by traits related to leaflet shape and indumentation, and calyx indumentation. We carried out morphometric analyses of 14 quantitative (continuous) leaf characters in order to assess the taxonomy of Hymenaea courbaril under the Unified Species Concept framework. Cluster analysis used the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) based on Bray-Curtis dissimilarity matrices. Principal Component Analyses (PCA) were carried out based on the same morphometric matrix. Two sets of Analyses of Similarity and Non Parametric Multivariate Analysis of Variance were carried out to evaluate statistical support (1) for the major groups recovered using UPGMA and PCA, and (2) for the varieties. All analyses recovered three major groups coincident with (1) var. altissima, (2) var. longifolia, and (3) all other varieties. These results, together with geographical and habitat information, were taken as evidence of three separate metapopulation lineages recognized here as three distinct species. Nomenclatural adjustments, including reclassifying formerly misapplied types, are proposed. PMID:25009440

Morphological analyses suggest a new taxonomic circumscription for Hymenaea courbaril L. (Leguminosae, Caesalpinioideae).

PubMed

Souza, Isys Mascarenhas; Funch, Ligia Silveira; de Queiroz, Luciano Paganucci

2014-01-01

Hymenaea is a genus of the Resin-producing Clade of the tribe Detarieae (Leguminosae: Caesalpinioideae) with 14 species. Hymenaea courbaril is the most widespread species of the genus, ranging from southern Mexico to southeastern Brazil. As currently circumscribed, Hymenaea courbaril is a polytypic species with six varieties: var. altissima, var. courbaril, var. longifolia, var. stilbocarpa, var. subsessilis, and var. villosa. These varieties are distinguishable mostly by traits related to leaflet shape and indumentation, and calyx indumentation. We carried out morphometric analyses of 14 quantitative (continuous) leaf characters in order to assess the taxonomy of Hymenaea courbaril under the Unified Species Concept framework. Cluster analysis used the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) based on Bray-Curtis dissimilarity matrices. Principal Component Analyses (PCA) were carried out based on the same morphometric matrix. Two sets of Analyses of Similarity and Non Parametric Multivariate Analysis of Variance were carried out to evaluate statistical support (1) for the major groups recovered using UPGMA and PCA, and (2) for the varieties. All analyses recovered three major groups coincident with (1) var. altissima, (2) var. longifolia, and (3) all other varieties. These results, together with geographical and habitat information, were taken as evidence of three separate metapopulation lineages recognized here as three distinct species. Nomenclatural adjustments, including reclassifying formerly misapplied types, are proposed.

Oil and fatty acid contents in seed of Citrullus lanatus Schrad.

PubMed

Jarret, Robert L; Levy, Irvin J

2012-05-23

Intact seed of 475 genebank accessions of Citrullus ( C. lanatus var. lanatus and C. lanatus var. citroides) were analyzed for percent oil content using TD-NMR. Extracts from whole seed of 96 accessions of C. lanatus (30 var. citroides, 33 var. lanatus, and 33 egusi), C. colocynthis (n = 3), C. ecirrhosus (n = 1), C. rehmii (n = 1), and Benincasa fistulosa (n = 3) were also analyzed for their fatty acids content. Among the materials analyzed, seed oil content varied from 14.8 to 43.5%. Mean seed oil content in egusi types of C. lanatus was significantly higher (mean = 35.6%) than that of either var. lanatus (mean = 23.2%) or var. citroides (mean = 22.6%). Egusi types of C. lanatus had a significantly lower hull/kernel ratio when compared to other C. lanatus var. lanatus or C. lanatus var. citroides. The principal fatty acid in all C. lanatus materials examined was linoleic acid (43.6-73%). High levels of linoleic acid were also present in the materials of C. colocynthis (71%), C. ecirrhosus (62.7%), C. rehmii (75.8%), and B. fistulosa (73.2%), which were included for comparative purposes. Most all samples contained traces (<0.5%) of arachidonic acid. The data presented provide novel information on the range in oil content and variability in the concentrations of individual fatty acids present in a diverse array of C. lanatus, and its related species, germplasm.

Serotype- and virulence-associated gene profile of Streptococcus suis isolates from pig carcasses in Chiang Mai Province, Northern Thailand

PubMed Central

WONGSAWAN, Kanruethai; GOTTSCHALK, Marcelo; THARAVICHITKUL, Prasit

2014-01-01

In this present study, the serotype of 40 Streptococcus suis isolates from submaxillary glands of pig carcasses sold in wet markets in Chiang Mai Province, northern Thailand, was investigated. Eleven serotypes, including types 2, 3, 4, 5, 7, 8, 9, 17, 21, 22 and 31, were found in the isolates by a Multiplex PCR combined with serum agglutination. Of the eleven serotypes present, type 3 was the most prevalent, while types 2, 4, 5 and 21 were of primary interest due to their human isolate serotype. The mrp+/epf − /sly − genotype was found to be the most prevalent genotype. This study indicates the importance of effective control of human S. suis infection due to raw pork or pig carcass handling in northern Thailand. PMID:25367105

Diversity of Salmonella isolates from central Florida surface waters.

PubMed

McEgan, Rachel; Chandler, Jeffrey C; Goodridge, Lawrence D; Danyluk, Michelle D

2014-11-01

Identification of Salmonella serotypes is important for understanding the environmental diversity of the genus Salmonella. This study evaluates the diversity of Salmonella isolates recovered from 165 of 202 Central Florida surface water samples and investigates whether the serotype of the environmental Salmonella isolates can be predicted by a previously published multiplex PCR assay (S. Kim, J. G. Frye, J. Hu, P. J. Fedorka-Cray, R. Gautom, and D. S. Boyle, J. Clin. Microbiol. 44:3608-3615, 2006, http://dx.doi.org/10.1128/JCM.00701-06). Multiplex PCR was performed on 562 Salmonella isolates (as many as 36 isolates per water sample) to predict serotypes. Kauffmann-White serogrouping was used to confirm multiplex PCR pattern groupings before isolates were serotyped, analyzed by pulsed-field gel electrophoresis, and assayed for antimicrobial susceptibility. In 41.2% of the Salmonella-positive water samples, all Salmonella isolates had identical multiplex PCR patterns; in the remaining 58.8%, two or more multiplex PCR patterns were identified. Within each sample, isolates with matching multiplex PCR patterns had matching serogroups. The multiplex patterns of 495 isolates (88.1%) did not match any previously reported pattern. The remaining 68 isolates matched reported patterns but did not match the serotypes for those patterns. The use of the multiplex PCR allowed the number of isolates requiring further analysis to be reduced to 223. Thirty-three Salmonella enterica serotypes were identified; the most frequent included serotypes Muenchen, Rubislaw, Anatum, Gaminara, and IV_50:z4,z23:-. A majority (141/223) of Salmonella isolates clustered into one genotypic group. Salmonella isolates in Central Florida surface waters are serotypically, genotypically, and phenotypically (in terms of antimicrobial susceptibility) diverse. While isolates could be grouped as different or potentially the same using multiplex PCR, the multiplex PCR pattern did not predict the Salmonella serotype. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Virulence Gene Sequencing Highlights Similarities and Differences in Sequences in Listeria monocytogenes Serotype 1/2a and 4b Strains of Clinical and Food Origin From 3 Different Geographic Locations.

PubMed

Poimenidou, Sofia V; Dalmasso, Marion; Papadimitriou, Konstantinos; Fox, Edward M; Skandamis, Panagiotis N; Jordan, Kieran

2018-01-01

The prfA -virulence gene cluster ( p VGC) is the main pathogenicity island in Listeria monocytogenes , comprising the prfA, plcA, hly, mpl, actA , and plcB genes. In this study, the p VGC of 36 L. monocytogenes isolates with respect to different serotypes (1/2a or 4b), geographical origin (Australia, Greece or Ireland) and isolation source (food-associated or clinical) was characterized. The most conserved genes were prfA and hly , with the lowest nucleotide diversity (π) among all genes ( P < 0.05), and the lowest number of alleles, substitutions and non-synonymous substitutions for prfA . Conversely, the most diverse gene was actA , which presented the highest number of alleles ( n = 20) and showed the highest nucleotide diversity. Grouping by serotype had a significantly lower π value ( P < 0.0001) compared to isolation source or geographical origin, suggesting a distinct and well-defined unit compared to other groupings. Among all tested genes, only hly and mpl were those with lower nucleotide diversity in 1/2a serotype than 4b serotype, reflecting a high within-1/2a serotype divergence compared to 4b serotype. Geographical divergence was noted with respect to the hly gene, where serotype 4b Irish strains were distinct from Greek and Australian strains. Australian strains showed less diversity in plcB and mpl relative to Irish or Greek strains. Notable differences regarding sequence mutations were identified between food-associated and clinical isolates in prfA, actA , and plcB sequences. Overall, these results indicate that virulence genes follow different evolutionary pathways, which are affected by a strain's origin and serotype and may influence virulence and/or epidemiological dominance of certain subgroups.

Global Distribution of Invasive Serotype 35D Streptococcus pneumoniae Isolates following Introduction of 13-Valent Pneumococcal Conjugate Vaccine.

PubMed

Lo, Stephanie W; Gladstone, Rebecca A; van Tonder, Andries J; Hawkins, Paulina A; Kwambana-Adams, Brenda; Cornick, Jennifer E; Madhi, Shabir A; Nzenze, Susan A; du Plessis, Mignon; Kandasamy, Rama; Carter, Philip E; Eser, Özgen Köseoglu; Ho, Pak Leung; Elmdaghri, Naima; Shakoor, Sadia; Clarke, Stuart C; Antonio, Martin; Everett, Dean B; von Gottberg, Anne; Klugman, Keith P; McGee, Lesley; Breiman, Robert F; Bentley, Stephen D

2018-07-01

A newly recognized pneumococcal serotype, 35D, which differs from the 35B polysaccharide in structure and serology by not binding to factor serum 35a, was recently reported. The genetic basis for this distinctive serology is due to the presence of an inactivating mutation in wciG , which encodes an O-acetyltransferase responsible for O-acetylation of a galactofuranose. Here, we assessed the genomic data of a worldwide pneumococcal collection to identify serotype 35D isolates and understand their geographical distribution, genetic background, and invasiveness potential. Of 21,980 pneumococcal isolates, 444 were originally typed as serotype 35B by PneumoCaT. Analysis of the wciG gene revealed 23 isolates from carriage ( n = 4) and disease ( n = 19) with partial or complete loss-of-function mutations, including mutations resulting in premature stop codons ( n = 22) and an in-frame mutation ( n = 1). These were selected for further analysis. The putative 35D isolates were geographically widespread, and 65.2% (15/23) of them was recovered after the introduction of pneumococcal conjugate vaccine 13 (PCV13). Compared with serotype 35B isolates, putative serotype 35D isolates have higher invasive disease potentials based on odds ratios (OR) (11.58; 95% confidence interval[CI], 1.42 to 94.19 versus 0.61; 95% CI, 0.40 to 0.92) and a higher prevalence of macrolide resistance mediated by mefA (26.1% versus 7.6%; P = 0.009). Using the Quellung reaction, 50% (10/20) of viable isolates were identified as serotype 35D, 25% (5/20) as serotype 35B, and 25% (5/20) as a mixture of 35B/35D. The discrepancy between phenotype and genotype requires further investigation. These findings illustrated a global distribution of an invasive serotype, 35D, among young children post-PCV13 introduction and underlined the invasive potential conferred by the loss of O-acetylation in the pneumococcal capsule. Copyright © 2018 Lo et al.

Diversity of Salmonella Isolates from Central Florida Surface Waters

PubMed Central

McEgan, Rachel; Chandler, Jeffrey C.; Goodridge, Lawrence D.

2014-01-01

Identification of Salmonella serotypes is important for understanding the environmental diversity of the genus Salmonella. This study evaluates the diversity of Salmonella isolates recovered from 165 of 202 Central Florida surface water samples and investigates whether the serotype of the environmental Salmonella isolates can be predicted by a previously published multiplex PCR assay (S. Kim, J. G. Frye, J. Hu, P. J. Fedorka-Cray, R. Gautom, and D. S. Boyle, J. Clin. Microbiol. 44:3608–3615, 2006, http://dx.doi.org/10.1128/JCM.00701-06). Multiplex PCR was performed on 562 Salmonella isolates (as many as 36 isolates per water sample) to predict serotypes. Kauffmann-White serogrouping was used to confirm multiplex PCR pattern groupings before isolates were serotyped, analyzed by pulsed-field gel electrophoresis, and assayed for antimicrobial susceptibility. In 41.2% of the Salmonella-positive water samples, all Salmonella isolates had identical multiplex PCR patterns; in the remaining 58.8%, two or more multiplex PCR patterns were identified. Within each sample, isolates with matching multiplex PCR patterns had matching serogroups. The multiplex patterns of 495 isolates (88.1%) did not match any previously reported pattern. The remaining 68 isolates matched reported patterns but did not match the serotypes for those patterns. The use of the multiplex PCR allowed the number of isolates requiring further analysis to be reduced to 223. Thirty-three Salmonella enterica serotypes were identified; the most frequent included serotypes Muenchen, Rubislaw, Anatum, Gaminara, and IV_50:z4,z23:−. A majority (141/223) of Salmonella isolates clustered into one genotypic group. Salmonella isolates in Central Florida surface waters are serotypically, genotypically, and phenotypically (in terms of antimicrobial susceptibility) diverse. While isolates could be grouped as different or potentially the same using multiplex PCR, the multiplex PCR pattern did not predict the Salmonella serotype. PMID:25172861

Adeno-Associated Virus Serotypes 1, 8, and 9 Share Conserved Mechanisms for Anterograde and Retrograde Axonal Transport

PubMed Central

Castle, Michael J.; Gershenson, Zachary T.; Giles, April R.; Holzbaur, Erika L.F.

2014-01-01

Abstract Adeno-associated virus (AAV) vectors often undergo long-distance axonal transport after brain injection. This leads to transduction of brain regions distal to the injection site, although the extent of axonal transport and distal transduction varies widely among AAV serotypes. The mechanisms driving this variability are poorly understood. This is a critical problem for applications that require focal gene expression within a specific brain region, and also impedes the utilization of vector transport for applications requiring widespread delivery of transgene to the brain. Here, we compared AAV serotypes 1 and 9, which frequently demonstrate distal transduction, with serotype 8, which rarely spreads beyond the injection site. To examine directional AAV transport in vitro, we used a microfluidic chamber to apply dye-labeled AAV to the axon termini or to the cell bodies of primary rat embryonic cortical neurons. All three serotypes were actively transported along axons, with transport characterized by high velocities and prolonged runs in both the anterograde and retrograde directions. Coinfection with pairs of serotypes indicated that AAV1, 8, and 9 share the same intracellular compartments for axonal transport. In vivo, both AAV8 and 9 demonstrated anterograde and retrograde transport within a nonreciprocal circuit after injection into adult mouse brain, with highly similar distributions of distal transduction. However, in mass-cultured neurons, we found that AAV1 was more frequently transported than AAV8 or 9, and that the frequency of AAV9 transport could be enhanced by increasing receptor availability. Thus, while these serotypes share conserved mechanisms for axonal transport both in vitro and in vivo, the frequency of transport can vary among serotypes, and axonal transport can be markedly increased by enhancing vector uptake. This suggests that variability in distal transduction in vivo likely results from differential uptake at the plasma membrane, rather than fundamental differences in transport mechanisms among AAV serotypes. PMID:24694006

Heterologous Expression of Ralp3 in Streptococcus pyogenes M2 and M6 Strains Affects the Virulence Characteristics

PubMed Central

Siemens, Nikolai; Kreikemeyer, Bernd

2013-01-01

Background Ralp3 is a transcriptional regulator present in a serotype specific fashion on the chromosome of the human pathogen Streptococcus pyogenes (group A streptococci, GAS). In serotypes harbouring the ralp3 gene either positive or negative effects on important metabolic and virulence genes involved in colonization and immune evasion in the human host were observed. A previous study revealed that deletion of ralp3 in a GAS M49 serotype significantly attenuated many virulence traits and caused metabolic disadvantages. This leads to two questions: (i) which kind of consequences could Ralp3 expression have in GAS serotypes naturally lacking this gene, and (ii) is Ralp3 actively lost during evolution in these serotypes. Methodology/Principal Findings We investigated the role of Ralp3 in GAS M2 and M6 pathogenesis. Both serotypes lack ralp3 on their chromosome. The heterologous expression of ralp3 in both serotypes resulted in reduced attachment to and internalization into the majority of tested epithelial cells. Both ralp3 expression strains showed a decreased ability to survive in human blood and exclusively M2::ralp3 showed decreased survival in human serum. Both mutants secreted more active SpeB in the supernatant, resulting in a higher activity compared to wild type strains. The respective M2 and M6 wild type strains outcompeted the ralp3 expression strains in direct metabolic competition assays. The phenotypic changes observed in the M2:ralp3 and M6:ralp3 were verified on the transcriptional level. Consistent with the virulence data, tested genes showed transcript level changes in the same direction. Conclusions/Significance Together these data suggest that Ralp3 can take over transcriptional control of virulence genes in serotypes lacking the ralp3 gene. Those serotypes most likely lost Ralp3 during evolution since obviously expression of this gene is disadvantageous for metabolism and pathogenesis. PMID:23424622

Heterologous expression of Ralp3 in Streptococcus pyogenes M2 and M6 strains affects the virulence characteristics.

PubMed

Siemens, Nikolai; Kreikemeyer, Bernd

2013-01-01

Ralp3 is a transcriptional regulator present in a serotype specific fashion on the chromosome of the human pathogen Streptococcus pyogenes (group A streptococci, GAS). In serotypes harbouring the ralp3 gene either positive or negative effects on important metabolic and virulence genes involved in colonization and immune evasion in the human host were observed. A previous study revealed that deletion of ralp3 in a GAS M49 serotype significantly attenuated many virulence traits and caused metabolic disadvantages. This leads to two questions: (i) which kind of consequences could Ralp3 expression have in GAS serotypes naturally lacking this gene, and (ii) is Ralp3 actively lost during evolution in these serotypes. We investigated the role of Ralp3 in GAS M2 and M6 pathogenesis. Both serotypes lack ralp3 on their chromosome. The heterologous expression of ralp3 in both serotypes resulted in reduced attachment to and internalization into the majority of tested epithelial cells. Both ralp3 expression strains showed a decreased ability to survive in human blood and exclusively M2::ralp3 showed decreased survival in human serum. Both mutants secreted more active SpeB in the supernatant, resulting in a higher activity compared to wild type strains. The respective M2 and M6 wild type strains outcompeted the ralp3 expression strains in direct metabolic competition assays. The phenotypic changes observed in the M2:ralp3 and M6:ralp3 were verified on the transcriptional level. Consistent with the virulence data, tested genes showed transcript level changes in the same direction. Together these data suggest that Ralp3 can take over transcriptional control of virulence genes in serotypes lacking the ralp3 gene. Those serotypes most likely lost Ralp3 during evolution since obviously expression of this gene is disadvantageous for metabolism and pathogenesis.

Assignment of serotype to Salmonella enterica isolates obtained from poultry and their environment in southern Brazil

PubMed Central

Pulido-Landínez, M; Sánchez-Ingunza, R; Guard, J; do Nascimento, V Pinheiro

2013-01-01

To assess diversity of Salmonella enterica serotypes present in poultry and their environment from southern Brazil, the Kauffmann–White–Le Minor (KWL) scheme was used to serotype a total of 155 isolates. Isolates were then re-examined with nested PCR and sequencing of the dkgB-linked intergenic sequence ribotyping (ISR) region that assesses single nucleotide polymorphisms occurring around a 5S ribosomal gene. Serotypes identified were Heidelberg (40·6%), Enteritidis (34·2%), Hadar (8·4%), Typhimurium (3·9%), Gallinarum (3·2%), Agona (1·3%), Cerro (1·3%), Livingstone (1·3%), Infantis (0·6%), Isangi (0·6%), Mbandaka (0·6%), Montevideo (0·6%) and Senftenberg (0·6%). Three unique ISRs were detected from four strains. Day old chicks yielded only S. Enteritidis, whereas S. Heidelberg was most often associated with poultry carcasses. Overall agreement between KWL and ISR was 85·2%, with disagreement possibly due to the ability of ISR to detect mixtures of serotypes in culture. Overall, ISR provided more information than did KWL about the ecology of Salm. enterica on-farm. The O-antigen group D Salm. enterica serovars such as Pullorum, Gallinarum and Enteritidis appear susceptible to overgrowth by other serotypes. Significance and Impact of the Study Single nucleotide polymorphisms found in a group of poultry-associated Salmonella isolates from southern Brazil provided evidence of mixtures of serovar group D serotypes on-farm and in single samples from birds. This finding suggests that co-infection and interserotype competition of Salmonella enterica in poultry could impact the incidence of disease in animals or humans. In addition, unique serotypes were identified on-farm that escaped characterization by antibody typing. Application of cost-efficient and highly discriminatory genomic methods for assigning serotype may alter concepts about the epidemiology of Salm. enterica on-farm and in foods. PMID:23734786

A hybrid approach to generating search subspaces in dynamically constrained 4-dimensional data assimilation

NASA Astrophysics Data System (ADS)

Yaremchuk, Max; Martin, Paul; Beattie, Christopher

2017-09-01

Development and maintenance of the linearized and adjoint code for advanced circulation models is a challenging issue, requiring a significant proportion of total effort in operational data assimilation (DA). The ensemble-based DA techniques provide a derivative-free alternative, which appears to be competitive with variational methods in many practical applications. This article proposes a hybrid scheme for generating the search subspaces in the adjoint-free 4-dimensional DA method (a4dVar) that does not use a predefined ensemble. The method resembles 4dVar in that the optimal solution is strongly constrained by model dynamics and search directions are supplied iteratively using information from the current and previous model trajectories generated in the process of optimization. In contrast to 4dVar, which produces a single search direction from exact gradient information, a4dVar employs an ensemble of directions to form a subspace in order to proceed. In the earlier versions of a4dVar, search subspaces were built using the leading EOFs of either the model trajectory or the projections of the model-data misfits onto the range of the background error covariance (BEC) matrix at the current iteration. In the present study, we blend both approaches and explore a hybrid scheme of ensemble generation in order to improve the performance and flexibility of the algorithm. In addition, we introduce balance constraints into the BEC structure and periodically augment the search ensemble with BEC eigenvectors to avoid repeating minimization over already explored subspaces. Performance of the proposed hybrid a4dVar (ha4dVar) method is compared with that of standard 4dVar in a realistic regional configuration assimilating real data into the Navy Coastal Ocean Model (NCOM). It is shown that the ha4dVar converges faster than a4dVar and can be potentially competitive with 4dvar both in terms of the required computational time and the forecast skill.

Lung abscess caused by Streptococcus pneumoniae serotype 6B.

PubMed

Ito, Yuhei; Toyoshima, Hirokazu; Suzuki, Takehiro; Iwamoto, Keisuke; Sasano, Hajime; Itani, Hidetoshi; Kondo, Shigeto; Tanigawa, Motoaki

2018-01-01

Lung abscess has been considered to be a rare complication of pneumococcal infection, and most cases are reported to be Streptococcus pneumoniae serotype 3. A 67-year-old man presented with fever and was diagnosed to have lung abscess caused by S. pneumoniae serotype 6B. The minimal inhibitory concentration (MIC) of penicillin for the isolate was 1 μg/mL. He was treated with high-dose intravenous sulbactam/ampicillin as definitive therapy based on susceptibility testing for S. pneumoniae and recovered successfully without surgical intervention. S. pneumoniae serotype 6B can cause lung abscess.

Survey of poliovirus antibodies in Borno and Yobe States, North-Eastern Nigeria

PubMed Central

Gofama, Mustapha Modu; Verma, Harish; Abdullahi, Hamisu; Craig, Kehinde T.; Urua, Utibe-Abasi; Garba, Mohammed Ashir; Alhaji, Mohammed Arab; Weldon, William C.; Oberste, M. Steven; Braka, Fiona; Muhammad, Ado J. G.; Sutter, Roland W.

2017-01-01

Background Nigeria remains one of only three polio-endemic countries in the world. In 2016, after an absence of 2 years, wild poliovirus serotype 1 was again detected in North-Eastern Nigeria. To better guide programmatic action, we assessed the immunity status of infants and children in Borno and Yobe states, and evaluated the impact of recently introduced inactivated poliovirus vaccine (IPV) on antibody seroprevalence. Methods and findings We conducted a facility-based study of seroprevalence to poliovirus serotypes 1, 2 and 3 among health-seeking patients in two sites each of Borno and Yobe States. Enrolment was conducted amongst children 6–9 and 36–47 months of age attending the paediatrics outpatient department of the selected hospitals in the two states between 11 January and 5 February 2016. Detailed demographic and immunization history of the child was taken and an assessment of the child’s health and nutritional state was conducted via physical examination. Blood was collected to test for levels of neutralizing antibody titres against the three poliovirus serotypes. The seroprevalence in the two age groups, potential determinants of seropositivity and the impact of one dose of IPV on humoral immunity were assessed. A total of 583 subjects were enrolled and provided sufficient quantities of serum for testing. Among 6-9-month-old infants, the seroprevalence was 81% (74–87%), 86% (79–91%), and 72% (65–79%) in Borno State, and 75% (67–81%), 74% (66–81%) and 69% (61–76%) in Yobe States, for serotypes-1, 2 and 3, respectively. Among children aged 36–47 months, the seroprevalence was >90% in both states for all three serotypes, with the exception of type 3 seroprevalence in Borno [87% (80–91%)]. Median reciprocal anti-polio neutralizing antibody titers were consistently >900 for serotypes 1 and 2 across age groups and states; with lower estimates for serotype 3, particularly in Borno. IPV received in routine immunization was found to be a significant determinant of seropositivity and anti-polio neutralizing antibodies among 6-9-month-old infants for serotypes 1 and 3, but demonstrated a non-significant positive association for serotype 2. Children receiving IPV through SIAs demonstrated significantly higher anti-polio neutralizing antibodies for serotypes 1 and 3. Conclusions The seroprevalence to poliovirus remains suboptimal in both Borno and Yobe States in Nigeria. The low seroprevalence facilitated the continued transmission of both wild serotype 1 and serotype 2 circulating vaccine-derived poliovirus detected in Borno State in 2016. Further efforts are necessary to improve the immunity status of these populations to ensure sufficient population immunity to interrupt transmission. PMID:28949979

Adeno-associated Virus (AAV) Assembly-Activating Protein Is Not an Essential Requirement for Capsid Assembly of AAV Serotypes 4, 5, and 11.

PubMed

Earley, Lauriel F; Powers, John M; Adachi, Kei; Baumgart, Joshua T; Meyer, Nancy L; Xie, Qing; Chapman, Michael S; Nakai, Hiroyuki

2017-02-01

Adeno-associated virus (AAV) vectors have made great progress in their use for gene therapy; however, fundamental aspects of AAV's capsid assembly remain poorly characterized. In this regard, the discovery of assembly-activating protein (AAP) sheds new light on this crucial part of AAV biology and vector production. Previous studies have shown that AAP is essential for assembly; however, how its mechanistic roles in assembly might differ among AAV serotypes remains uncharacterized. Here, we show that biological properties of AAPs and capsid assembly processes are surprisingly distinct among AAV serotypes 1 to 12. In the study, we investigated subcellular localizations and assembly-promoting functions of AAP1 to -12 (i.e., AAPs derived from AAV1 to -12, respectively) and examined the AAP dependence of capsid assembly processes of these 12 serotypes using combinatorial approaches that involved immunofluorescence and transmission electron microscopy, barcode-Seq (i. e., a high-throughput quantitative method using DNA barcodes and a next-generation sequencing technology), and quantitative dot blot assays. This study revealed that AAP1 to -12 are all localized in the nucleus with serotype-specific differential patterns of nucleolar association; AAPs and assembled capsids do not necessarily colocalize; AAPs are promiscuous in promoting capsid assembly of other serotypes, with the exception of AAP4, -5, -11, and -12; assembled AAV5, -8, and -9 capsids are excluded from the nucleolus, in contrast to the nucleolar enrichment of assembled AAV2 capsids; and, surprisingly, AAV4, -5, and -11 capsids are not dependent on AAP for assembly. These observations highlight the serotype-dependent heterogeneity of the capsid assembly process and challenge current notions about the role of AAP and the nucleolus in capsid assembly. Assembly-activating protein (AAP) is a recently discovered adeno-associated virus (AAV) protein that promotes capsid assembly and provides new opportunities for research in assembly. Previous studies on AAV serotype 2 (AAV2) showed that assembly takes place in the nucleolus and is dependent on AAP and that capsids colocalize with AAP in the nucleolus during the assembly process. However, through the investigation of 12 different AAV serotypes (AAV1 to -12), we find that AAP is not an essential requirement for capsid assembly of AAV4, -5, and -11, and AAP, assembled capsids, and the nucleolus do not colocalize for all the serotypes. In addition, we find that there are both serotype-restricted and serotype-promiscuous AAPs in their assembly roles. These findings challenge widely held beliefs about the importance of the nucleolus and AAP in AAV assembly and show the heterogeneous nature of the assembly process within the AAV family. Copyright © 2017 American Society for Microbiology.

Efficient transformation and expression of gfp gene in Valsa mali var. mali.

PubMed

Chen, Liang; Sun, Gengwu; Wu, Shujing; Liu, Huixiang; Wang, Hongkai

2015-01-01

Valsa mali var. mali, the causal agent of valsa canker of apple, causes great loss of apple production in apple producing regions. The pathogenic mechanism of the pathogen has not been studied extensively, thus a suitable gene marker for pathogenic invasion analysis and a random insertion of T-DNA for mutants are desirable. In this paper, we reported the construction of a binary vector pKO1-HPH containing a positive selective gene hygromycin phosphotransferase (hph), a reporter gene gfp conferring green fluorescent protein, and an efficient protocol for V. mali var. mali transformation mediated by Agrobacterium tumefaciens. A transformation efficiency up to about 75 transformants per 10(5) conidia was achieved when co-cultivation of V. mali var. mali and A. tumefaciens for 48 h in A. tumefaciens inductive medium agar plates. The insertions of hph gene and gfp gene into V. mali var. mali genome verified by polymerase chain reaction and southern blot analysis showed that 10 randomly-selected transformants exhibited a single, unique hybridization pattern. This is the first report of A. tumefaciens-mediated transformation of V. mali var mali carrying a 'reporter' gfp gene that stably and efficiently expressed in the transformed V. mali var. mali species.

Development and characterization of 16 polymorphic microsatellite markers from Taiwan cow-tail fir, Keteleeria davidiana var. formosana (Pinaceae) and cross-species amplification in other Keteleeria taxa

PubMed Central

2014-01-01

Background Keteleeria davidiana var. formosana (Pinaceae), Taiwan cow-tail fir, is an endangered species listed on the IUCN Red List of Threatened Species and only two populations remain, both on the Taiwan Island. Sixteen polymorphic microsatellite loci were developed in an endangered and endemic gymnosperm species, Keteleeria davidiana var. formosana, and were tested in an additional 6 taxa, K. davidiana var. calcarea, K. davidiana var. chienpeii, K. evelyniana, K. fortunei, K. fortunei var. cyclolepis, and K. pubescens, to evaluate the genetic variation available for conservation management and to reconstruct the phylogeographic patterns of this ancient lineage. Findings Polymorphic primer sets were developed from K. davidiana var. formosana using the modified AFLP and magnetic bead enrichment method. The number of alleles ranged from 3 to 16, with the observed heterozygosity ranging from 0.28 to 1.00. All of the loci were found to be interspecifically amplifiable. Conclusions These polymorphic and transferable loci will be potentially useful for future studies that will focus on identifying distinct evolutionary units within species and establishing the phylogeographic patterns and the process of speciation among closely related species. PMID:24755442

The diversity of Klebsiella pneumoniae surface polysaccharides.

PubMed

Follador, Rainer; Heinz, Eva; Wyres, Kelly L; Ellington, Matthew J; Kowarik, Michael; Holt, Kathryn E; Thomson, Nicholas R

2016-08-01

Klebsiella pneumoniae is considered an urgent health concern due to the emergence of multi-drug-resistant strains for which vaccination offers a potential remedy. Vaccines based on surface polysaccharides are highly promising but need to address the high diversity of surface-exposed polysaccharides, synthesized as O-antigens (lipopolysaccharide, LPS) and K-antigens (capsule polysaccharide, CPS), present in K. pneumoniae . We present a comprehensive and clinically relevant study of the diversity of O- and K-antigen biosynthesis gene clusters across a global collection of over 500 K. pneumoniae whole-genome sequences and the seroepidemiology of human isolates from different infection types. Our study defines the genetic diversity of O- and K-antigen biosynthesis cluster sequences across this collection, identifying sequences for known serotypes as well as identifying novel LPS and CPS gene clusters found in circulating contemporary isolates. Serotypes O1, O2 and O3 were most prevalent in our sample set, accounting for approximately 80 % of all infections. In contrast, K serotypes showed an order of magnitude higher diversity and differ among infection types. In addition we investigated a potential association of O or K serotypes with phylogenetic lineage, infection type and the presence of known virulence genes. K1 and K2 serotypes, which are associated with hypervirulent K. pneumoniae , were associated with a higher abundance of virulence genes and more diverse O serotypes compared to other common K serotypes.

Twenty Years of Listeria in Brazil: Occurrence of Listeria Species and Listeria monocytogenes Serovars in Food Samples in Brazil between 1990 and 2012

PubMed Central

Vallim, Deyse Christina; Barroso Hofer, Cristina; Lisbôa, Rodrigo de Castro; Victor Barbosa, André; Alves Rusak, Leonardo; dos Reis, Cristhiane Moura Falavina; Hofer, Ernesto

2015-01-01

Listeria spp. isolated from different food products and collected from 12 Brazilian states were sent to the Laboratory of Bacterial Zoonoses (Oswaldo Cruz Institute, Brazil) for identification. The aims of this study were to characterize these isolates, from 1990 to 2012, by using biochemical, morphological, and serotyping tests, and to analyze the distribution of L. monocytogenes serotypes on different food products and geographical locations. Serotyping was performed using polyclonal somatic and flagellar antisera. Of 5953 isolates, 5770 were identified as Listeria spp., from which 3429 (59.4%) were L. innocua, 2248 (38.9%) were L. monocytogenes, and 93 (1.6%) were other Listeria spp. L. innocua was predominantly isolated from 1990 to 2000, while L. monocytogenes was from 2001 to 2012. Regarding the serotype distribution in the foods, serotypes 1/2a and 4b were most common in processed meat and ready-to-eat products, respectively; serotypes 1/2a, 1/2b, and 4b were the most common in nonprocessed meat. The results above confirm the presence of the main serotypes of L. monocytogenes in different parts of the food chain from three regions of the country and emphasize the importance of improving the control measures, as tolerance zero policy and microbiological surveillance in Brazil. PMID:26539507

Epigenetic regulation of serotype expression antagonizes transcriptome dynamics in Paramecium tetraurelia.

PubMed

Cheaib, Miriam; Dehghani Amirabad, Azim; Nordström, Karl J V; Schulz, Marcel H; Simon, Martin

2015-08-01

Phenotypic variation of a single genotype is achieved by alterations in gene expression patterns. Regulation of such alterations depends on their time scale, where short-time adaptations differ from permanently established gene expression patterns maintained by epigenetic mechanisms. In the ciliate Paramecium, serotypes were described for an epigenetically controlled gene expression pattern of an individual multigene family. Paradoxically, individual serotypes can be triggered in Paramecium by alternating environments but are then stabilized by epigenetic mechanisms, thus raising the question to which extend their expression follows environmental stimuli. To characterize environmental adaptation in the context of epigenetically controlled serotype expression, we used RNA-seq to characterize transcriptomes of serotype pure cultures. The resulting vegetative transcriptome resource is first analysed for genes involved in the adaptive response to the altered environment. Secondly, we identified groups of genes that do not follow the adaptive response but show co-regulation with the epigenetically controlled serotype system, suggesting that their gene expression pattern becomes manifested by similar mechanisms. In our experimental set-up, serotype expression and the entire group of co-regulated genes were stable among environmental changes and only heat-shock genes altered expression of these gene groups. The data suggest that the maintenance of these gene expression patterns in a lineage represents epigenetically controlled robustness counteracting short-time adaptation processes. © The Author 2015. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

Chlamydia trachomatis serotype A infections in the Amazon region of Brazil: prevalence, entry and dissemination.

PubMed

Ishak, Marluísa de Oliveira Guimarães; Costa, Maurimélia Mesquita; Almeida, Núbia Caroline Costa de; Santiago, Angélica Menezes; Brito, William Botelho de; Vallinoto, Antonio Carlos Rosário; Azevedo, Vânia Nakauth; Ishak, Ricardo

2015-01-01

Chlamydia infection is associated with debilitating human diseases including trachoma, pneumonia, coronary heart disease and urogenital diseases. Serotypes of C. trachomatis show a fair correlation with the group of diseases they cause, and their distribution follows a well-described geographic pattern. Serotype A, a trachoma-associated strain, is known for its limited dissemination in the Middle East and Northern Africa. However, knowledge on the spread of bacteria from the genus Chlamydia as well as the distribution of serotypes in Brazil is quite limited. Blood samples of 1,710 individuals from ten human population groups in the Amazon region of Brazil were examined for antibodies to Chlamydia using indirect immunofluorescence and microimmunofluorescence assays. The prevalence of antibodies to Chlamydia ranged from 23.9% (Wayana-Apalai) to 90.7% (Awa-Guaja) with a mean prevalence of 50.2%. Seroreactivity was detected to C. pneumoniae and to all serotypes of C. trachomatis tested; furthermore, we report clear evidence of the as-yet-undescribed occurrence of serotype A of C. trachomatis. Specific seroreactivity not only accounts for the large extent of dissemination of C. trachomatis in the Amazon region of Brazil but also shows an expanded area of occurrence of serotype A outside the epidemiological settings previously described. Furthermore, these data suggest possible routes of Chlamydia introduction into the Amazon region from the massive human migration that occurred during the 1,700s.

Community Circulation Patterns of Oral Polio Vaccine Serotypes 1, 2, and 3 After Mexican National Immunization Weeks

PubMed Central

Troy, Stephanie B.; Ferreyra-Reyes, Leticia; Huang, ChunHong; Sarnquist, Clea; Canizales-Quintero, Sergio; Nelson, Christine; Báez-Saldaña, Renata; Holubar, Marisa; Ferreira-Guerrero, Elizabeth; García-García, Lourdes; Maldonado, Yvonne A.

2014-01-01

Background. With wild poliovirus nearing eradication, preventing circulating vaccine-derived poliovirus (cVDPV) by understanding oral polio vaccine (OPV) community circulation is increasingly important. Mexico, where OPV is given only during biannual national immunization weeks (NIWs) but where children receive inactivated polio vaccine (IPV) as part of their primary regimen, provides a natural setting to study OPV community circulation. Methods. In total, 216 children and household contacts in Veracruz, Mexico, were enrolled, and monthly stool samples and questionnaires collected for 1 year; 2501 stool samples underwent RNA extraction, reverse transcription, and real-time polymerase chain reaction (PCR) to detect OPV serotypes 1, 2, and 3. Results. OPV was detected up to 7 months after an NIW, but not at 8 months. In total, 35% of samples collected from children vaccinated the prior month, but only 4% of other samples, contained OPV. Although each serotype was detected in similar proportions among OPV strains shed as a result of direct vaccination, 87% of OPV acquired through community spread was serotype 2 (P < .0001). Conclusions. Serotype 2 circulates longer and is transmitted more readily than serotypes 1 or 3 after NIWs in a Mexican community primarily vaccinated with IPV. This may be part of the reason why most isolated cVDPV has been serotype 2. PMID:24367038

Serotype determination of Salmonella by xTAG assay.

PubMed

Zheng, Zhibei; Zheng, Wei; Wang, Haoqiu; Pan, Jincao; Pu, Xiaoying

2017-10-01

Currently, no protocols or commercial kits are available to determine the serotypes of Salmonella by using Luminex MAGPIX®. In this study, an xTAG assay for serotype determination of Salmonella suitable for Luminex MAGPIX® is described and 228 Salmonella isolates were serotype determined by this xTAG assay. The xTAG assay consists of two steps: 1) Multiplex PCR to amplify simultaneously O, H and Vi antigen genes of Salmonella, and 2) Magplex-TAG™ microsphere hybridization to identify accurately the specific PCR products of different antigens. Compared with the serotyping results of traditional serum agglutination test, the sensitivity and specificity of the xTAG assay were 95.1% and 100%, respectively. The agreement rate of these two assays was 95.2%. Compared with Luminex xMAP® Salmonella Serotyping Assay (SSA) kit, the advantages of this xTAG assay are: First, the magnetic beads make it applicable to both the Luminex®100/200™ and MAGPIX® systems. Second, only primers rather than both primers and probes are needed in the xTAG assay, and the process of coupling antigen-specific oligonucleotide probes to beads is circumvented, which make the xTAG assay convenient to be utilized by other laboratories. The xTAG assay may serve as a rapid alternative or complementary method for traditional Salmonella serotyping tests, especially for laboratories that utilize the MAGPIX® systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Complete genome sequence of the first bluetongue virus serotype 7 isolate from China: evidence for entry of African-lineage strains and reassortment between the introduced and native strains.

PubMed

Yang, Heng; Lv, Minna; Sun, Minfei; Lin, Liqin; Kou, Meilin; Gao, Lin; Liao, Defang; Xiong, Heli; He, Yuwen; Li, Huachun

2016-01-01

Bluetongue virus (BTV) mainly infects sheep but can be transmitted to other domestic and wild ruminants, resulting in a considerable financial burden and trade restriction. Our understanding of the origin, movement, and distribution of BTV has been hindered by the fact that this virus has a segmented genome with the possibility of reassortment, the existence of 27 identified serotypes, and a lack of complete sequences of viruses isolated from different parts of the world. BTV serotype 7 is one of the prevalent BTV serotypes in Asia. Nonetheless, no complete genomic sequence of an Asian isolate of this serotype is available. In an effort to understand the molecular epidemiology of BTV infection in China, for the first time, we report here the complete genome sequence of a BTV serotype 7 strain, GDST008, which was isolated in 2014 in China. This sequence also represents the first complete genome sequence of a BTV serotype 7 from Asia and the third one in the world. Sequence analysis suggests that GDST008 consists of segments from BTV viruses of African lineage as well as those from China. Together, these results improve our understanding of the origin, emergence/re-emergence, and movement of BTV and thus can be applied in the development of vaccines and diagnostics.

The diversity of Klebsiella pneumoniae surface polysaccharides

PubMed Central

Heinz, Eva; Wyres, Kelly L.; Ellington, Matthew J.; Kowarik, Michael; Holt, Kathryn E.; Thomson, Nicholas R.

2016-01-01

Klebsiella pneumoniae is considered an urgent health concern due to the emergence of multi-drug-resistant strains for which vaccination offers a potential remedy. Vaccines based on surface polysaccharides are highly promising but need to address the high diversity of surface-exposed polysaccharides, synthesized as O-antigens (lipopolysaccharide, LPS) and K-antigens (capsule polysaccharide, CPS), present in K. pneumoniae. We present a comprehensive and clinically relevant study of the diversity of O- and K-antigen biosynthesis gene clusters across a global collection of over 500 K. pneumoniae whole-genome sequences and the seroepidemiology of human isolates from different infection types. Our study defines the genetic diversity of O- and K-antigen biosynthesis cluster sequences across this collection, identifying sequences for known serotypes as well as identifying novel LPS and CPS gene clusters found in circulating contemporary isolates. Serotypes O1, O2 and O3 were most prevalent in our sample set, accounting for approximately 80 % of all infections. In contrast, K serotypes showed an order of magnitude higher diversity and differ among infection types. In addition we investigated a potential association of O or K serotypes with phylogenetic lineage, infection type and the presence of known virulence genes. K1 and K2 serotypes, which are associated with hypervirulent K. pneumoniae, were associated with a higher abundance of virulence genes and more diverse O serotypes compared to other common K serotypes. PMID:28348868

Dengue serotype-specific immune response in Aedes aegypti and Aedes albopictus.

PubMed

Smartt, Chelsea T; Shin, Dongyoung; Alto, Barry W

2017-12-01

Dengue viruses (DENV) are considered one of the most important emerging pathogens and dengue disease is a global health threat. The geographic expansion of dengue viruses has led to co-circulation of all four dengue serotypes making it imperative that new DENV control strategies be devised. Here we characterize dengue serotype-specific innate immune responses in Aedes aegypti and Aedes albopictus using DENV from Puerto Rico (PR). Ae. aegypti and Ae. albopictus were infected with dengue serotype 1 and 2 isolated from Puerto Rico. DENV infected mosquito samples were collected and temporal change in expression of selected innate immune response pathway genes analyzed by quantitative real time PCR. The Toll pathway is involved in anti-dengue response in Ae. aegypti, and Ae. albopictus. Infections with PR DENV- 1 elicited a stronger response from genes of the Toll immune pathway than PR DENV-2 in Ae. aegypti but in infected Ae. albopictus expression of Toll pathway genes tended to be similar between the serotypes. Two genes (a ribosomal S5 protein gene and a nimrod-like gene) from Ae. albopictus were expressed in response to DENV. These studies revealed a role for antiviral genes in DENV serotype-specific interactions with DENV vectors, demonstrated that infections with DENV-2 can modulate the Toll immune response pathway in Ae. aegypti and elucidated candidate molecules that might be used to interfere with serotype specific vector-virus interactions.

A triplex quantitative real-time PCR assay for differential detection of human adenovirus serotypes 2, 3 and 7.

PubMed

Qiu, Fang-Zhou; Shen, Xin-Xin; Zhao, Meng-Chuan; Zhao, Li; Duan, Su-Xia; Chen, Chen; Qi, Ju-Ju; Li, Gui-Xia; Wang, Le; Feng, Zhi-Shan; Ma, Xue-Jun

2018-05-02

Human adenovirus (HAdV) serotypes 2, 3 and 7 are more prevalent than other serotypes and have been associated with severe pneumonia in pediatric children. Molecular typing of HAdV is not routinely performed in clinical diagnostic laboratories as it is time-consuming and labor-intensive. In the present study, we developed a triplex quantitative real-time PCR assay (tq-PCR) in a single closed tube for differential detection and quantitative analysis of HAdV serotypes 2, 3 and 7. The sensitivity, specificity, reproducibility and clinical performance of tq-PCR were evaluated. The analytical sensitivity of the tq-PCR was 100 copies/reaction for each of HAdV serotypes 2, 3 and 7, and no cross-reaction with other common respiratory viruses or HAdV serotypes 1,4,5,6,31,55 and 57 was observed. The coefficients of variation (CV) of intra-assay and inter-assay were between 0.6% to 3.6%. Of 138 previously-defined HAdV-positive nasopharyngeal aspirates samples tested, the detection agreement between tq-PCR and nested PCR was 96.38% (133/138). The proposed tq-PCR assay is a sensitive, specific and reproducible method and has the potential for clinical use in the rapid and differential detection and quantitation of HAdV serotypes 2, 3 and 7.

Serotype distribution of invasive Streptococcus pneumoniae in Canada during the introduction of the 13-valent pneumococcal conjugate vaccine, 2010.

PubMed

Demczuk, Walter H B; Martin, Irene; Griffith, Averil; Lefebvre, Brigitte; McGeer, Allison; Shane, Amanda; Zhanel, George G; Tyrrell, Gregory J; Gilmour, Matthew W

2012-08-01

A baseline serotype distribution was established by age and region for 2058 invasive Streptococcus pneumoniae isolates collected during the implementation period of the 13-valent pneumococcal conjugate vaccine (PCV13) program in many parts of Canada in 2010. Serotypes 19A, 7F, and 3 were the most prevalent in all age groups, accounting for 57% in <2 year olds, 62% in 2-4 year olds, 45% in 5-14 year olds, 44% in 15-49 year olds, 41% in 50-64 year olds, and 36% in ≥65 year olds. Serotype 19A was most predominant in Western and Central Canada representing 15% and 22%, respectively, of the isolates from those regions, whereas 7F was most common in Eastern Canada with 20% of the isolates. Other prevalent serotypes include 15A, 23B, 12F, 22F, and 6C. PCV13 serotypes represented 65% of the pneumococci isolated from <2 year olds, 71% of 2-4 year olds, 61% of 5-14 year olds, 60% of 15-49 year olds, 53% of 50-64 year olds, and 49% of the ≥65 year olds. Continued monitoring of invasive pneumococcal serotypes in Canada is important to identify epidemiological trends and assess the impact of the newly introduced PCV13 vaccine on public health.

Fluorescence Spectra of Individual Flowing Airborne Biological Particles Measured in Real Time

DTIC Science & Technology

2001-02-01

and fungal spores ( Aspergillus versicolor, ATCC 9577). B. subtilis var. niger (lyophilized cells) and E. herbicola were grown by streak- ing onto...Excitation Figure 7 shows fluorescence spectra of B. subtilis var. niger vegetative cells and fungal spores ( Aspergillus versicolor), both 5 µm in diameter...µm-diam clusters of B. subtilis var. niger spores, and B. subtilis var. niger vegetative cells ……………………………………… 10 5. Fluorescence spectra of starved

An unusual clinical presentation of tinea faciei caused by Trichophyton mentagrophytes var. erinacei.

PubMed

Lee, Deok-Woo; Yang, Ji-Hye; Choi, Seok-Joo; Won, Chong-Hyun; Chang, Sung-Eun; Lee, Mi-Woo; Choi, Jee-Ho; Moon, Kee-Chan; Kim, Mi-Na

2011-01-01

Trichophyton mentagrophytes var. erinacei, the natural host of which is the hedgehog, has been found to cause highly inflammatory and pruritic eruptions, including tinea manuum, tinea corporis, nail infection, kerion, scalp infection, and tinea barbae. To our knowledge, however, no reports have been made of tinea faciei caused by Trichophyton mentagrophytes var. erinacei in the English language literature. We provide here the case of tinea faciei caused by Trichophyton mentagrophytes var. erinacei. © 2011 Wiley Periodicals, Inc.

Aviation Trainer Technology Test Plan. Volume II. Software Development

DTIC Science & Technology

1991-11-25

feild values in new node *Ieg>X=x newg->X = Y newg->Len =len; newg->Help =help; newg->Ignore = ignore; newg->Format = format; newg->Validation - NULL;I... vector : North long varVFE; /* F-16A velocity vector : East long varVFU; /* F-16A velocity vector : Up */ long varH; /* plane heading */ long varC; /* plane...31\\\\ETH523.sys" parmsdr.args=getds(); parmsdr.non7=OxOO; /*save interrupt vector for future restoration */ cSavvecso; rc=getdso; rc=cInitParameters

Modelling of volatility in monetary transmission mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dobešová, Anna; Klepáč, Václav; Kolman, Pavel

2015-03-10

The aim of this paper is to compare different approaches to modeling of volatility in monetary transmission mechanism. For this purpose we built time-varying parameter VAR (TVP-VAR) model with stochastic volatility and VAR-DCC-GARCH model with conditional variance. The data from three European countries are included in the analysis: the Czech Republic, Germany and Slovakia. Results show that VAR-DCC-GARCH system captures higher volatility of observed variables but main trends and detected breaks are generally identical in both approaches.

Parentage determination of Vanda Miss Joaquim (Orchidaceae) through two chloroplast genes rbcL and matK

PubMed Central

Khew, Gillian Su-Wen; Chia, Tet Fatt

2011-01-01

Background and aims The popular hybrid orchid Vanda Miss Joaquim was made Singapore's national flower in 1981. It was originally described in the Gardeners’ Chronicle in 1893, as a cross between Vanda hookeriana and Vanda teres. However, no record had been kept as to which parent contributed the pollen. This study was conducted using DNA barcoding techniques to determine the pod parent of V. Miss Joaquim, thereby inferring the pollen parent of the hybrid by exclusion. Methodology Two chloroplast genes, matK and rbcL, from five related taxa, V. hookeriana, V. teres var. alba, V. teres var. andersonii, V. teres var. aurorea and V. Miss Joaquim ‘Agnes’, were sequenced. The matK gene from herbarium specimens of V. teres and V. Miss Joaquim, both collected in 1893, was also sequenced. Principal results No sequence variation was found in the 600-bp region of rbcL sequenced. Sequence variation was found in the matK gene of V. hookeriana, V. teres var. alba, V. teres var. aurorea and V. Miss Joaquim ‘Agnes’. Complete sequence identity was established between V. teres var. andersonii and V. Miss Joaquim ‘Agnes’. The matK sequences obtained from the herbarium specimens of V. teres and V. Miss Joaquim were completely identical to the sequences obtained from the fresh samples of V. teres var. andersonii and V. Miss Joaquim ‘Agnes’. Conclusions The pod parent of V. Miss Joaquim ‘Agnes’ is V. teres var. andersonii and, by exclusion, the pollen parent is V. hookeriana. The herbarium and fresh samples of V. teres var. andersonii and V. Miss Joaquim share the same inferred maternity. The matK gene was more informative than rbcL and facilitated differentiation of varieties of V. teres. PMID:22476488

Transcriptome sequence analysis of an ornamental plant, Ananas comosus var. bracteatus, revealed the potential unigenes involved in terpenoid and phenylpropanoid biosynthesis.

PubMed

Ma, Jun; Kanakala, S; He, Yehua; Zhang, Junli; Zhong, Xiaolan

2015-01-01

Ananas comosus var. bracteatus (Red Pineapple) is an important ornamental plant for its colorful leaves and decorative red fruits. Because of its complex genome, it is difficult to understand the molecular mechanisms involved in the growth and development. Thus high-throughput transcriptome sequencing of Ananas comosus var. bracteatus is necessary to generate large quantities of transcript sequences for the purpose of gene discovery and functional genomic studies. The Ananas comosus var. bracteatus transcriptome was sequenced by the Illumina paired-end sequencing technology. We obtained a total of 23.5 million high quality sequencing reads, 1,555,808 contigs and 41,052 unigenes. In total 41,052 unigenes of Ananas comosus var. bracteatus, 23,275 unigenes were annotated in the NCBI non-redundant protein database and 23,134 unigenes were annotated in the Swiss-Port database. Out of these, 17,748 and 8,505 unigenes were assigned to gene ontology categories and clusters of orthologous groups, respectively. Functional annotation against Kyoto Encyclopedia of Genes and Genomes Pathway database identified 5,825 unigenes which were mapped to 117 pathways. The assembly predicted many unigenes that were previously unknown. The annotated unigenes were compared against pineapple, rice, maize, Arabidopsis, and sorghum. Unigenes that did not match any of those five sequence datasets are considered to be Ananas comosus var. bracteatus unique. We predicted unigenes encoding enzymes involved in terpenoid and phenylpropanoid biosynthesis. The sequence data provide the most comprehensive transcriptomic resource currently available for Ananas comosus var. bracteatus. To our knowledge; this is the first report on the de novo transcriptome sequencing of the Ananas comosus var. bracteatus. Unigenes obtained in this study, may help improve future gene expression, genetic and genomics studies in Ananas comosus var. bracteatus.

Transcriptome Sequence Analysis of an Ornamental Plant, Ananas comosus var. bracteatus, Revealed the Potential Unigenes Involved in Terpenoid and Phenylpropanoid Biosynthesis

PubMed Central

Ma, Jun; Kanakala, S.; He, Yehua; Zhang, Junli; Zhong, Xiaolan

2015-01-01

Background Ananas comosus var. bracteatus (Red Pineapple) is an important ornamental plant for its colorful leaves and decorative red fruits. Because of its complex genome, it is difficult to understand the molecular mechanisms involved in the growth and development. Thus high-throughput transcriptome sequencing of Ananas comosus var. bracteatus is necessary to generate large quantities of transcript sequences for the purpose of gene discovery and functional genomic studies. Results The Ananas comosus var. bracteatus transcriptome was sequenced by the Illumina paired-end sequencing technology. We obtained a total of 23.5 million high quality sequencing reads, 1,555,808 contigs and 41,052 unigenes. In total 41,052 unigenes of Ananas comosus var. bracteatus, 23,275 unigenes were annotated in the NCBI non-redundant protein database and 23,134 unigenes were annotated in the Swiss-Port database. Out of these, 17,748 and 8,505 unigenes were assigned to gene ontology categories and clusters of orthologous groups, respectively. Functional annotation against Kyoto Encyclopedia of Genes and Genomes Pathway database identified 5,825 unigenes which were mapped to 117 pathways. The assembly predicted many unigenes that were previously unknown. The annotated unigenes were compared against pineapple, rice, maize, Arabidopsis, and sorghum. Unigenes that did not match any of those five sequence datasets are considered to be Ananas comosus var. bracteatus unique. We predicted unigenes encoding enzymes involved in terpenoid and phenylpropanoid biosynthesis. Conclusion The sequence data provide the most comprehensive transcriptomic resource currently available for Ananas comosus var. bracteatus. To our knowledge; this is the first report on the de novo transcriptome sequencing of the Ananas comosus var. bracteatus. Unigenes obtained in this study, may help improve future gene expression, genetic and genomics studies in Ananas comosus var. bracteatus. PMID:25769053

Evaluation of immunogenicity and safety of VARIVAX™ New Seed Process (NSP) in children.

PubMed

Senders, Shelly D; Bundick, Nickoya D; Li, Jianing; Zecca, Carol; Helmond, Frans A

2018-02-01

Prior to availability of an effective vaccine, an estimated 4 million cases of varicella occurred annually in the United States, resulting in 10,000 hospitalizations and over 100 deaths. With the increased usage of a two-dose varicella vaccine (as recommended by the ACIP), approval of other VZV-containing products and the adoption of varicella vaccination in additional countries, the demand for VZV-containing vaccines has increased. This study (NCT02062502) evaluated the safety, tolerability, and immunogenicity of VARIVAX™ (VAR, varicella vaccine live) manufactured using a new seed manufacturing process (VAR NSP ) compared to the currently licensed VAR. Healthy children 12-23 months were randomized (1:1) into Group 1 (2 doses of VAR NSP given concomitantly with M-M-R™ II, ∼3 months apart) versus  Group 2 (2 doses of VAR given concomitantly with M-M-R™ II, ∼3 months apart).  Serum samples collected prior to vaccination on Day 1 and 6 weeks Postdose 1 were tested for antibody to VZV using a glycoprotein enzyme-linked immunosorbent assay (gpELISA).  Safety was assessed Days 1 to 42 following each vaccination. Six weeks Postdose 1, the response rate (percent of subjects with VZV antibody titer ≥5 gpELISA units/mL) of VAR NSP was non-inferior compared to VAR.  Vaccine-related adverse events (AEs) were comparable with the exception of measles-like rash, where a greater number of rashes were observed with VAR than VAR NSP .  The 2 vaccination groups were comparable with incidence rates of AEs, injection-site AEs, vaccine-related AEs, systemic AEs, and serious AEs. This new process is an important innovation for the extreme demand of sustaining sufficient supplies of varicella vaccine to protect our communities against diseases caused by VZV.

The role of gtcA in the pathogenesis of gastrointestinal listeriosis in mice

USDA-ARS?s Scientific Manuscript database

Serotype 4b strains of Listeria monocytogenes have been responsible for most large outbreaks of listeriosis. In L. monocytogenes serotype 4b, gtcA and gltA have been implicated in serotype-specific glycosylation of the teichoic acid of the cell wall with galactose and glucose. In this study, we inve...

Assignment of serotype to Salmonella enterica isolates obtained from poultry and their environment in Southern Brazil.

USDA-ARS?s Scientific Manuscript database

To assess diversity of Salmonella enterica serotypes present in poultry and their environment from Southern Brazil, the Kauffman-White-LeMinor (KWL) scheme was used to serotype a total of 155 isolates. Isolates were then re-examined with nested PCR and sequencing of the dkgB-linked Intergenic Sequ...

Unrecognized Dengue Virus Infections in Children, Western Kenya, 2014-2015.

PubMed

Vu, David M; Mutai, Noah; Heath, Claire J; Vulule, John M; Mutuku, Francis M; Ndenga, Bryson A; LaBeaud, A Desiree

2017-11-01

We detected a cluster of dengue virus infections in children in Kenya during July 2014-June 2015. Most cases were serotype 1, but we detected all 4 serotypes, including co-infections with 2 serotypes. Our findings implicate dengue as a cause of febrile illness in this population and highlight a need for robust arbovirus surveillance.

Evaluation of a dkgB linked intergenic sequence ribotyping (ISR) method for assigning serotype to Salmonella enterica isolated from poultry environmental samples.

USDA-ARS?s Scientific Manuscript database

The Kauffman White (KW) serotyping method requires more than 250 antisera to characterize more than 2,500 Salmonella serovars. The complexity of serotyping could be overcome using molecular methods. In this study, a dkgB-linked intergenic sequence ribotyping (ISR) method that generates sequence occu...

A monoclonal antibody based capture ELISA for botulinum neurotoxin serotype B: toxin detection in food

USDA-ARS?s Scientific Manuscript database

Botulism is a serious foodborne neuroparalyic disease caused by botulinum neurotoxin (BoNT) produced by the anaerobic bacterium Clostridium botulinum. Seven toxin serotypes (A-H) have been described. The majority of human cases of botulism are caused by serotypes A and B followed by E and F. We repo...

Meningitis Associated with Simultaneous Infection by Multiple Dengue Virus Serotypes in Children, Brazil.

PubMed

Marinho, Paula Eillanny Silva; Bretas de Oliveira, Danilo; Candiani, Talitah Michel Sanchez; Crispim, Ana Paula Correia; Alvarenga, Pedro Paulo Martins; Castro, Fabrizia Cristina Dos Santos; Abrahão, Jonatas Santos; Rios, Maria; Coimbra, Roney Santos; Kroon, Erna Geessien

2017-01-01

To determine the causes of viral meningitis, we analyzed 22 cerebrospinal fluid samples collected during the 2014-2015 dengue epidemics in Brazil. We identified 3 serotypes of dengue virus (DENV-1, -2, and -3), as well as co-infection with 2 or 3 serotypes. We also detected the Asian II genotype of DENV-2.

[Study on chemical constituents of volatile oil from rhizomes and leaves of Pileostegia viburnoides var. glabrescens by GC-MS].

PubMed

Zou, Ju-Ying; Chen, Sheng-Huang; Li, Qin-Wen; Chen, Han-Jun; Liu, Bei-Bei; Du, Fan

2012-04-01

To analyze the chemical constituents of volatile oil from the rhizomes and leaves of Pileostegia viburnoides var. glabrescens by GC-MS. The volatile oil was extracted from the rhizomes and leaves of Pileostegia viburnoides var. glabrescens by steam distillation. The constituents of volatile oil were identified by GC-MS technology. 37 compounds were identified from the oil of rhizomes. 36 compounds were identified from the oil of leaves. The rhizomes and leaves volatile oil had 18 compounds in common. This study is the first one to report the volatile components of Pileostegia viburnoides var. glabrescens. It can provide a scientific basis for rational use of the rhizomes and leaves of Pileostegia viburnoides var. glabrescens.

Different metabolic profiles of K1 serotype and non-serotype K1 and K2 Klebsiella pneumoniae isolates in oral infection mice model.

PubMed

Chen, Nan; Wang, Lin-Lin; Xue, Juan; Ma, Xiang-Bo; Zhao, Sheng; Rong, Rui-Xue; Li, Hong-Quan; Ding, Liang; Zheng, Ming-Zhi; Chen, Ying-Ying; Duan, Fei; Shen, Yue-Liang

2014-10-01

K1 or K2 serotype Klebsiella pneumoniae isolate caused clinical pyogenic liver abscess (KLA) infection is prevalent in many areas. It has been identified that K1 or K2 serotype K. pneumoniae isolates caused KLA infection in mice by oral inoculation. In our study, K1 serotype K. pneumoniae isolate Kp1002 with hypermucoviscosity (HV)-positive phenotype caused KLA infection in C57BL/6 mice by oral inoculation. Simultaneously, non-serotype K1 and K2 isolate Kp1014 with HV-negative phenotype failed to cause KLA infection in the same manner. It seems that gastrointestinal tract translocation is the pathway by which K1 or K2 serotype K. pneumoniae caused KLA infection. Liquid chromatography-tandem mass spectrometry was used to further analyze metabolic profile changes in mice with KLA infection. Data showed that after Kp1002 or Kp1014 oral inoculation, serum Phosphatidylcholine (PC) and Lysophosphatidylcholine (LPC) levels significantly changed in mice. Some PC and LPC molecules showed changes both in the Kp1002 KLA group and the Kp1014 no-KLA group compared with the control group. The level of 18:1/18:2-PC significantly changed in the Kp1002 KLA group compared with the control group, but showed no change between the Kp1014 no-KLA group and the control group. The level of 18:1/18:2-PC might have been particularly affected by KLA infection caused by K1 serotype K. pneumoniae Kp1002. It may be a potential biomarker for KLA infection. Copyright © 2014 Elsevier Ltd. All rights reserved.

Genetic and pathogenic difference between Streptococcus agalactiae serotype Ia fish and human isolates.

PubMed

Chu, Chishih; Huang, Pei-Yu; Chen, Hung-Ming; Wang, Ying-Hsiang; Tsai, I-An; Lu, Chih-Cheng; Chen, Che-Chun

2016-08-02

Streptococcus agalactiae (GBS) is a common pathogen to infect newborn, woman, the elderly, and immuno-compromised human and fish. 37 fish isolates and 554 human isolates of the GBS in 2007-2012 were investigated in serotypes, antibiotic susceptibility, genetic difference and pathogenicity to tilapia. PCR serotyping determined serotype Ia for all fish GBS isolates and only in 3.2 % (3-4.2 %) human isolates. For fish isolates, all consisted a plasmid less than 6 kb and belonged to ST7 type, which includes mainly pulsotypes I and Ia, with a difference in a deletion at the largest DNA fragment. These fish isolates were susceptible to all antimicrobials tested in 2007 and increased in non-susceptibility to penicillin, and resistance to clindamycin and ceftriaxone in 2011. Differing in pulsotype and lacking plasmid from fish isolates, human serotype Ia isolates were separated into eight pulsotypes II-IX. Main clone ST23 included pulsotypes II and IIa (50 %) and ST483 consisted of pulsotype III. Human serotype Ia isolates were all susceptible to ceftriaxone and penicillin and few were resistant to erythromycin, azithromycin, clindamycin, levofloxacin and moxifloxacine with the resistant rate of 20 % or less. Using tilapia to analyze the pathogenesis, fish isolates could cause more severe symptoms, including hemorrhage of the pectoral fin, hemorrhage of the gill, and viscous black and common scites, and mortality (>95 % for pulsotype I) than the human isolates (<30 %); however, the fish pulostype Ia isolate 912 with deletion caused less symptoms and the lowest mortality (<50 %) than pulsotype I isolates. Genetic, pathogenic, and antimicrobial differences demonstrate diverse origin of human and fish serotype Ia isolates. The pulsotype Ia of fish serotype Ia isolates may be used as vaccine strains to prevent the GBS infection in fish.

Influenza A Virus Infection Predisposes Hosts to Secondary Infection with Different Streptococcus pneumoniae Serotypes with Similar Outcome but Serotype-Specific Manifestation.

PubMed

Sharma-Chawla, Niharika; Sender, Vicky; Kershaw, Olivia; Gruber, Achim D; Volckmar, Julia; Henriques-Normark, Birgitta; Stegemann-Koniszewski, Sabine; Bruder, Dunja

2016-12-01

Influenza A virus (IAV) and Streptococcus pneumoniae are major causes of respiratory tract infections, particularly during coinfection. The synergism between these two pathogens is characterized by a complex network of dysregulated immune responses, some of which last until recovery following IAV infection. Despite the high serotype diversity of S. pneumoniae and the serotype replacement observed since the introduction of conjugate vaccines, little is known about pneumococcal strain dependency in the enhanced susceptibility to severe secondary S. pneumoniae infection following IAV infection. Thus, we studied how preinfection with IAV alters host susceptibility to different S. pneumoniae strains with various degrees of invasiveness using a highly invasive serotype 4 strain, an invasive serotype 7F strain, and a carrier serotype 19F strain. A murine model of pneumococcal coinfection during the acute phase of IAV infection showed a significantly increased degree of pneumonia and mortality for all tested pneumococcal strains at otherwise sublethal doses. The incidence and kinetics of systemic dissemination, however, remained bacterial strain dependent. Furthermore, we observed strain-specific alterations in the pulmonary levels of alveolar macrophages, neutrophils, and inflammatory mediators ultimately affecting immunopathology. During the recovery phase following IAV infection, bacterial growth in the lungs and systemic dissemination were enhanced in a strain-dependent manner. Altogether, this study shows that acute IAV infection predisposes the host to lethal S. pneumoniae infection irrespective of the pneumococcal serotype, while the long-lasting synergism between IAV and S. pneumoniae is bacterial strain dependent. These results hold implications for developing tailored therapeutic treatment regimens for dual infections during future IAV outbreaks. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

[Prevalence of HPV high-risk serotypes detected by PCR in patients with normal cervical cytology at the Hospital Regional Adolfo López Mateos, ISSSTE].

PubMed

Martínez-Portilla, R J; López-Velázquez, J L; Martínez-Rojas, G C; Aguilar-Villagómez, M I; De la Torre-Rendón, F E; Villafán-Bernal, J R

2016-09-01

Is fundamental to determine the prevalence of human papiloma virus (HVP) high-risk serotypes in local and regional population in order for health providers to offer patients, vaccines and treatments against specific population-based serotypes. To determine the prevalence of HPV High risk serotypes detected by PCR in patients with normal cytology from the ISSSTE Adolfo Lopez Mateos Regional Hospital. An observational, descriptive, prospective study was conducted from cervical cytologies and high risk HPV test by PCR in patients from the Regional Hospital Adolfo López Mateos, ISSSTE, during the period January 2013-December 2015. Cases of patients with negative cervical cytology were included. Information about age, the result of cervical cytology and high risk HPV test by PCR was obtained. The overall prevalence of HPV infection and the most prevalent serotypes by age groups were calculated. A total of 3258 cervical smears were performed, of which 2557 were negative (78.4%), from this, the global prevalence of HPV infection was 10.2% (n=262). We found that 1.8% (n = 45) of negative reports had HPV16 infection, 0.5% (n=13) had HPV18 and 8.9% (n = 227) were infected by Viral Pool of other high-risk serotypes. The prevalence of infection by viral pool of high risk serotypes was 11.5% in women <20 years, 12.9% in women between 20-29 years and 22.2% in women between 30-39 years. This prevalence was lower in patients older than 40 years (p<0.05). A higher prevalence of viral pool high risk serotypes was found in patients with normal cytology, than the HPV16 and HPV-8 prevalence, which was significantly higher in women younger than 40 years.

Genetic characterization of Shiga toxin-producing Escherichia coli (STEC) and atypical enteropathogenic Escherichia coli (EPEC) isolates from goat's milk and goat farm environment.

PubMed

Álvarez-Suárez, María-Elena; Otero, Andrés; García-López, María-Luisa; Dahbi, Ghizlane; Blanco, Miguel; Mora, Azucena; Blanco, Jorge; Santos, Jesús A

2016-11-07

The aim of this study was to characterize a collection of 44 Shiga toxin-producing (STEC) and enteropathogenic Escherichia coli (EPEC) isolated from goat milk and goat farm environment. Of the 19 STEC isolates, five (26.3%) carried the stx1 gene, four (21.1%) the stx2 gene and 10 (52.6%) presented both stx genes. Six (31.6%) STEC strains were eae-positive and belonged to serotypes related to severe human disease (O157:H7 and O5:HNM). Another seven STEC strains were of serotype O146:H21 and three of serotype O166:H28, also linked to human disease. The STEC strains isolated from goat milk were of serotypes potentially pathogenic for humans. All the 25 EPEC isolates were considered atypical (aEPEC) and one aEPEC strain was of serotype O26:H11, a serotype frequently isolated in children with diarrhea. Multilocus sequence typing (MLST) was carried out with seven housekeeping genes and 23 sequence types (ST) were detected, 14 of them newly described. Twelve STs grouped STEC isolates and 11 STs grouped EPEC isolates. Genetic typing by pulsed field gel electrophoresis (PFGE) resulted in 38 patterns which grouped in 10 clusters. Well-defined groups were also observed for strains of pathogenic serotypes. In conclusion, strains of STEC and aEPEC belonging to serotypes related to severe human disease have been detected in goat milk and the goat farm environment. Ruminants are an important reservoir of STEC strains and the role of these animals as carriers of other pathogenic types of E. coli seems to be an emerging concern. Copyright © 2016 Elsevier B.V. All rights reserved.

High-Pressure Inactivation of Rotaviruses: Role of Treatment Temperature and Strain Diversity in Virus Inactivation

PubMed Central

Araud, Elbashir; DiCaprio, Erin; Yang, Zhihong; Li, Xinhui; Lou, Fangfei; Hughes, John H.; Chen, Haiqiang

2015-01-01

Rotavirus (RV) is the major etiological agent of acute gastroenteritis in infants worldwide. Although high-pressure processing (HPP) is a popular method to inactivate enteric pathogens in food, the sensitivity of different virus strains within same species and serotype to HPP is variable. This study aimed to compare the barosensitivities of seven RV strains derived from four serotypes (serotype G1, strains Wa, Ku, and K8; serotype G2, strain S2; serotype G3, strains SA-11 and YO; and serotype G4, strain ST3) following high-pressure treatment. RV strains showed various responses to HPP based on the initial temperature and had different inactivation profiles. Ku, K8, S2, SA-11, YO, and ST3 showed enhanced inactivation at 4°C compared to 20°C. In contrast, strain Wa was not significantly impacted by the initial treatment temperature. Within serotype G1, strain Wa was significantly (P < 0.05) more resistant to HPP than strains Ku and K8. Overall, the resistance of the human RV strains to HPP at 4°C can be ranked as Wa > Ku = K8 > S2 > YO > ST3, and in terms of serotype the ranking is G1 > G2 > G3 > G4. In addition, pressure treatment of 400 MPa for 2 min was sufficient to eliminate the Wa strain, the most pressure-resistant RV, from oyster tissues. HPP disrupted virion structure but did not degrade viral protein or RNA, providing insight into the mechanism of viral inactivation by HPP. In conclusion, HPP is capable of inactivating RV at commercially acceptable pressures, and the efficacy of inactivation is strain dependent. PMID:26187961

Slaughterhouse pigs are a major reservoir of Streptococcus suis serotype 2 capable of causing human infection in southern Vietnam.

PubMed

Ngo, Thi Hoa; Tran, Thi Bich Chieu; Tran, Thi Thu Nga; Nguyen, Van Dung; Campbell, James; Pham, Hong Anh; Huynh, Huu Tho; Nguyen, Van Vinh Chau; Bryant, Juliet E; Tran, Tinh Hien; Farrar, Jeremy; Schultsz, Constance

2011-03-28

Streptococcus suis is a pathogen of major economic significance to the swine industry and is increasingly recognized as an emerging zoonotic agent in Asia. In Vietnam, S. suis is the leading cause of bacterial meningitis in adult humans. Zoonotic transmission is most frequently associated with serotype 2 strains and occupational exposure to pigs or consumption of infected pork. To gain insight into the role of pigs for human consumption as a reservoir for zoonotic infection in southern Vietnam, we determined the prevalence and diversity of S. suis carriage in healthy slaughterhouse pigs. Nasopharyngeal tonsils were sampled from pigs at slaughterhouses serving six provinces in southern Vietnam and Ho Chi Minh City area from September 2006 to November 2007. Samples were screened by bacterial culture. Isolates of S. suis were serotyped and characterized by multi locus sequence typing (MLST) and pulse field gel electrophoresis (PFGE). Antibiotic susceptibility profiles and associated genetic resistance determinants, and the presence of putative virulence factors were determined. 41% (222/542) of pigs carried S. suis of one or multiple serotypes. 8% (45/542) carried S. suis serotype 2 which was the most common serotype found (45/317 strains, 14%). 80% of serotype 2 strains belonged to the MLST clonal complex 1,which was previously associated with meningitis cases in Vietnam and outbreaks of severe disease in China in 1998 and 2005. These strains clustered with representative strains isolated from patients with meningitis in PFGE analysis, and showed similar antimicrobial resistance and virulence factor profiles. Slaughterhouse pigs are a major reservoir of S. suis serotype 2 capable of causing human infection in southern Vietnam. Strict hygiene at processing facilities, and health education programs addressing food safety and proper handling of pork should be encouraged.

Streptococcus pneumoniae serotype prevalence and antibiotic resistance among young children with invasive pneumococcal disease: experience from a tertiary care center in South India.

PubMed

Nagaraj, Savitha; Kalal, Bhuvanesh Sukhlal; Manoharan, Anand; Shet, Anita

2017-06-01

We performed a study to describe the clinical profile, antimicrobial susceptibility and prevalent serotypes of pneumococcal isolates from children with suspected invasive pneumococcal disease (IPD) admitted to a tertiary care hospital in South India. Hospitalized children, ≤ 5 years with fever (>38 °C); increased respiratory rate or neurological symptoms were recruited, (as part of the Alliance for Surveillance of Invasive Pneumococci - ASIP - project) from January 2011 to March 2013. Identification of pneumococcal isolates from blood or cerebrospinal fluid samples was done by routine culture methods. Isolates were analyzed for antimicrobial susceptibility, and confirmed by serotyping (using Quellung's test) and multiplex PCR. Out of the 171 samples received in the lab, 17 grew pneumococci identified by standard methods. Fourteen of them were confirmed by multiplex PCR. Maximum recruitment was observed during the months of January and February (36.4%, 28.6%). The average age of affected subjects was 21 months. The common clinical presentation was pneumonia (42.8%). Two isolates belonging to the 19F and 19B serotypes were resistant to penicillin (on Etest). The observed serotype distribution was 6B and 19F (2 each), and 1, 2, 6A, 9V, 10A, 14, 15A, 19B, 21, 35F (1 each). The overall fatality rate was 14.3% (n=2); the S. pneumoniae isolates from these two patients belonged to the non-vaccine serotype 19B and vaccine serotype 19F and demonstrated in vitro resistance to penicillin and erythromycin. Our study demonstrates the presence of invasive pneumococcal disease among under-5-year-old children in India caused by serotypes that are in large part covered by available pneumococcal vaccines.

Streptococcus pneumoniae serotype prevalence and antibiotic resistance among young children with invasive pneumococcal disease: experience from a tertiary care center in South India

PubMed Central

Nagaraj, Savitha; Kalal, Bhuvanesh Sukhlal; Manoharan, Anand; Shet, Anita

2017-01-01

Introduction We performed a study to describe the clinical profile, antimicrobial susceptibility and prevalent serotypes of pneumococcal isolates from children with suspected invasive pneumococcal disease (IPD) admitted to a tertiary care hospital in South India. Methods Hospitalized children, ≤ 5 years with fever (>38 °C); increased respiratory rate or neurological symptoms were recruited, (as part of the Alliance for Surveillance of Invasive Pneumococci – ASIP – project) from January 2011 to March 2013. Identification of pneumococcal isolates from blood or cerebrospinal fluid samples was done by routine culture methods. Isolates were analyzed for antimicrobial susceptibility, and confirmed by serotyping (using Quellung’s test) and multiplex PCR. Results Out of the 171 samples received in the lab, 17 grew pneumococci identified by standard methods. Fourteen of them were confirmed by multiplex PCR. Maximum recruitment was observed during the months of January and February (36.4%, 28.6%). The average age of affected subjects was 21 months. The common clinical presentation was pneumonia (42.8%). Two isolates belonging to the 19F and 19B serotypes were resistant to penicillin (on Etest). The observed serotype distribution was 6B and 19F (2 each), and 1, 2, 6A, 9V, 10A, 14, 15A, 19B, 21, 35F (1 each). The overall fatality rate was 14.3% (n=2); the S. pneumoniae isolates from these two patients belonged to the non-vaccine serotype 19B and vaccine serotype 19F and demonstrated in vitro resistance to penicillin and erythromycin. Conclusion Our study demonstrates the presence of invasive pneumococcal disease among under-5-year-old children in India caused by serotypes that are in large part covered by available pneumococcal vaccines. PMID:28626738

Clonal Expansion of the Macrolide Resistant ST386 within Pneumococcal Serotype 6C in France

PubMed Central

Janoir, Claire; Cohen, Robert; Levy, Corinne; Bingen, Edouard; Lepoutre, Agnès; Gutmann, Laurent; Varon, Emmanuelle

2014-01-01

In France, the use of the 7-valent pneumococcal conjugate vaccine (PCV7) lead to an overall significant decrease in PCV7 invasive pneumococcal disease (IPD) incidence. However, the decrease in vaccine serotype prevalence was partially counterbalanced by the serotype replacement phenomenon. In this study, we analyzed the role of the newly described serotype 6C as one of the replacement serotypes. This work was conducted on a large time scale from the early PCV7 era (2002–2003) to the PCV13 era (2010–2011), both on IPD strains recovered from the whole population and nasopharyngeal colonizing strains isolated in infant less than two years, who are known to be the main reservoir for pneumococci. Serotype 6C took advantage over 6A and 6B serotypes, which both decreased over time. A continuous and significant increase in 6C IPD was observed in adults along the study period; in contrast, in children less than two years, only an increase in 6C nasopharyngeal carriage was found, the prevalence of serotype 6C in IPD remaining very low over time. Among 101 6C invasive and colonizing strains studied by MLST, 24 STs were found to be related to three major clonal complexes, CC395, CC176, and CC315. STs related to CC176 tend to disappear after 2009 and were essentially replaced by ST386 (CC315), which dramatically increased over time. This clonal expansion may be explained by the erythromycin and tetracycline resistances associated with this clone. Finally, the decrease observed in nasopharyngeal 6C carriage since 2010, likely related to the PCV13 introduction in the French immunization schedule, is expected to lead to a decrease in 6C IPD in adults thereafter. PMID:24603763

O-Serotype Conversion in Salmonella Typhimurium Induces Protective Immune Responses against Invasive Non-Typhoidal Salmonella Infections.

PubMed

Li, Pei; Liu, Qing; Luo, Hongyan; Liang, Kang; Yi, Jie; Luo, Ying; Hu, Yunlong; Han, Yue; Kong, Qingke

2017-01-01

Salmonella infections remain a big problem worldwide, causing enteric fever by Salmonella Typhi (or Paratyphi) or self-limiting gastroenteritis by non-typhoidal Salmonella (NTS) in healthy individuals. NTS may become invasive and cause septicemia in elderly or immuno-compromised individuals, leading to high mortality and morbidity. No vaccines are currently available for preventing NTS infection in human. As these invasive NTS are restricted to several O-antigen serogroups including B1, D1, C1, and C2, O-antigen polysaccharide is believed to be a good target for vaccine development. In this study, a strategy of O-serotype conversion was investigated to develop live attenuated S . Typhimurium vaccines against the major serovars of NTS infections. The immunodominant O4 serotype of S . Typhimurium was converted into O9, O7, and O8 serotypes through unmarked chromosomal deletion-insertion mutations. O-serotype conversion was confirmed by LPS silver staining and western blotting. All O-serotype conversion mutations were successfully introduced into the live attenuated S . Typhimurium vaccine S738 (Δ crp Δ cya ) to evaluate their immunogenicity in mice model. The vaccine candidates induced high amounts of heterologous O-polysaccharide-specific functional IgG responses. Vaccinated mice survived a challenge of 100 times the 50% lethality dose (LD 50 ) of wild-type S . Typhimurium. Protective efficacy against heterologous virulent Salmonella challenges was highly O-serotype related. Furthermore, broad-spectrum protection against S . Typhimurium, S . Enteritidis, and S . Choleraesuis was observed by co-vaccination of O9 and O7 O-serotype-converted vaccine candidates. This study highlights the strategy of expressing heterologous O-polysaccharides via genetic engineering in developing live attenuated S . Typhimurium vaccines against NTS infections.

Salmonella prevalence among reptiles in a zoo education setting.

PubMed

Hydeskov, H B; Guardabassi, L; Aalbaek, B; Olsen, K E P; Nielsen, S S; Bertelsen, M F

2013-06-01

Clinically healthy reptiles may shed Salmonella and therefore act as a potential zoonotic threat. Most people in Northern European countries are rarely exposed to reptiles, but many zoos have education departments where children have direct contact with this group of animals. The objectives of this study were to determine the prevalence and serotype distribution of Salmonella among reptiles in the Education Department (n = 55) at Copenhagen Zoo and compare it to the Zoo's main reptile collection (n = 145) to evaluate the zoonotic risk. Salmonella was isolated from cloacal swabs by selective enrichment, and a single isolate from each positive sample was further identified by biochemical tests and serotyped. The overall prevalence was 35% (69/200) with significant difference between the Education Department (64%, 35/55) and the main reptile collection (23%, 34/145). A total of 28 serotypes were detected. Ten serotypes were isolated from more than one specimen and four from more than one species. Salmonella enterica subsp. enterica serovar Eastbourne was the predominant serotype (32%, 22/69) and was also the serotype isolated from most reptile species (n = 7). Transmission of serotypes from one department to another was very limited indicated by the serotype distribution. Despite the relative high prevalence observed among the reptiles in the Zoo's Education Department compared to the reptiles in the Zoo's main reptile collection, no Salmonella cases have been linked to the Zoo, and Salmonella ser. Eastbourne is very rarely isolated from humans in Denmark. Simple hygienic procedures such as hand washing which is consistently carried out following handling of reptiles at the Education Department may reduce the risk and therefore contribute to this low prevalence. © 2012 Blackwell Verlag GmbH.

Streptococcus agalactiae isolates of serotypes Ia, III and V from human and cow are able to infect tilapia.

PubMed

Chen, Ming; Wang, Rui; Luo, Fu-Guang; Huang, Yan; Liang, Wan-Wen; Huang, Ting; Lei, Ai-Ying; Gan, Xi; Li, Li-Ping

2015-10-22

Recent studies have shown that group B streptococcus (GBS) may be infectious across hosts. The purpose of this study is to investigate the pathogenicity of clinical GBS isolates with serotypes Ia, III and V from human and cow to tilapia and the evolutionary relationship among these GBS strains of different sources. A total of 27 clinical GBS isolates from human (n=10), cow (n=2) and tilapia (n=15) were analyzed using serotyping, multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Among them, 15 isolates were tested for their pathogenicity to tilapia. The results showed that five human GBS strains (2 serotype III, 2 serotype Ia and 1 serotype V) infected tilapia with mortality rate ranging from 56.67% to 100%, while the other five human GBS strains tested were unable to infect tilapia. In addition, two cow GBS strains C001 and C003 of serotype III infected tilapia. However, they had significantly lower pathogenicity than the five human strains. Furthermore, human GBS strains H005 and H008, which had very strong ability to infect tilapia, had the same PFGE pattern. MLST analysis showed that the five human and the two cow GBS strains that were able to infect tilapia belonged to clonal complexes CC19, CC23 and CC103. The study for the first time confirmed that human or cow GBS clonal complexes CC19, CC23 and CC103 containing strains with serotypes Ia, III and V could infect tilapia and induce clinical signs under experimental conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

Population-based genetic epidemiologic analysis of Chlamydia trachomatis serotypes and lack of association between ompA polymorphisms and clinical phenotypes.

PubMed

Millman, Kim; Black, Carolyn M; Stamm, Walter E; Jones, Robert B; Hook, Edward W; Martin, David H; Bolan, Gail; Tavaré, Simon; Dean, Deborah

2006-03-01

Chlamydia trachomatis is the leading cause of bacterial sexually transmitted diseases worldwide. Urogenital strains are classified into serotypes and genotypes based on the major outer membrane protein and its gene, ompA, respectively. Studies of the association of serotypes with clinical signs and symptoms have produced conflicting results while no studies have evaluated associations with ompA polymorphisms. We designed a population-based cross-sectional study of 344 men and women with urogenital chlamydial infections (excluding co-pathogen infections) presenting to clinics serving five U.S. cities from 1995 to 1997. Signs, symptoms and sequelae of chlamydial infection (mucopurulent cervicitis, vaginal or urethral discharge; dysuria; lower abdominal pain; abnormal vaginal bleeding; and pelvic inflammatory disease) were analyzed for associations with serotype and ompA polymorphisms. One hundred and fifty-three (44.5%) of 344 patients had symptoms consistent with urogenital chlamydial infection. Gender, reason for visit and city were significant independent predictors of symptom status. Men were 2.2 times more likely than women to report any symptoms (P=0.03) and 2.8 times more likely to report a urethral discharge than women were to report a vaginal discharge in adjusted analyses (P=0.007). Differences in serotype or ompA were not predictive except for an association between serotype F and pelvic inflammatory disease (P=0.046); however, the number of these cases was small. While there was no clinically prognostic value associated with serotype or ompA polymorphism for urogenital chlamydial infections except for serotype F, future studies might utilize multilocus genomic typing to identify chlamydial strains associated with clinical phenotypes.

Characterization of the RpoS Status of Clinical Isolates of Salmonella enterica

PubMed Central

Robbe-Saule, Véronique; Algorta, Gabriela; Rouilhac, Isabelle; Norel, Françoise

2003-01-01

The stationary-phase-inducible sigma factor, σS (RpoS), is the master regulator of the general stress response in Salmonella and is required for virulence in mice. rpoS mutants can frequently be isolated from highly passaged laboratory strains of Salmonella. We examined the rpoS status of 116 human clinical isolates of Salmonella, including 41 Salmonella enterica serotype Typhi strains isolated from blood, 38 S. enterica serotype Typhimurium strains isolated from blood, and 37 Salmonella serotype Typhimurium strains isolated from feces. We examined the abilities of these strains to produce the σS protein, to express RpoS-dependent catalase activity, and to resist to oxidative stress in the stationary phase of growth. We also carried out complementation experiments with a cloned wild-type rpoS gene. Our results showed that 15 of the 41 Salmonella serotype Typhi isolates were defective in RpoS. We sequenced the rpoS allele of 12 strains. This led to identification of small insertions, deletions, and point mutations resulting in premature stop codons or affecting regions 1 and 2 of σS, showing that the rpoS mutations are not clonal. Thus, mutant rpoS alleles can be found in freshly isolated clinical strains of Salmonella serotype Typhi, and they may affect virulence properties. Interestingly however, no rpoS mutants were found among the 75 Salmonella serotype Typhimurium isolates. Strains that differed in catalase activity and resistance to hydrogen peroxide were found, but the differences were not linked to the rpoS status. This suggests that Salmonella serotype Typhimurium rpoS mutants are counterselected because rpoS plays a role in the pathogenesis of Salmonella serotype Typhimurium in humans or in the transmission cycle of the disease. PMID:12902215

Production of latex agglutination reagents for pneumococcal serotyping

PubMed Central

2013-01-01

Background The current ‘gold standard’ for serotyping pneumococci is the Quellung test. This technique is laborious and requires a certain level of training to correctly perform. Commercial pneumococcal latex agglutination serotyping reagents are available, but these are expensive. In-house production of latex agglutination reagents can be a cost-effective alternative to using commercially available reagents. This paper describes a method for the production and quality control (QC) of latex reagents, including problem solving recommendations, for pneumococcal serotyping. Results Here we describe a method for the production of latex agglutination reagents based on the passive adsorption of antibodies to latex particles. Sixty-five latex agglutination reagents were made using the PneuCarriage Project (PCP) method, of which 35 passed QC. The other 30 reagents failed QC due to auto-agglutination (n=2), no reactivity with target serotypes (n=8) or cross-reactivity with non-target serotypes (n=20). Dilution of antisera resulted in a further 27 reagents passing QC. The remaining three reagents passed QC when prepared without centrifugation and wash steps. Protein estimates indicated that latex reagents that failed QC when prepared using the PCP method passed when made with antiserum containing ≤ 500 μg/ml of protein. Sixty-one nasopharyngeal isolates were serotyped with our in-house latex agglutination reagents, with the results showing complete concordance with the Quellung reaction. Conclusions The method described here to produce latex agglutination reagents allows simple and efficient serotyping of pneumococci and may be applicable to latex agglutination reagents for typing or identification of other microorganisms. We recommend diluting antisera or removing centrifugation and wash steps for any latex reagents that fail QC. Our latex reagents are cost-effective, technically undemanding to prepare and remain stable for long periods of time, making them ideal for use in low-income countries. PMID:23379961

Characterization of 12 polymorphic microsatellite loci of Pityopsis graminifolia var. latifolia

USDA-ARS?s Scientific Manuscript database

Pityopsis graminifolia (Michx.) Small var. latifolia (Fern.) Semple is an herbaceous perennial that grows in close proximity to the federally endangered species P. ruthii (Small) Small. Twelve polymorphic microsatellite loci were identified from 87 samples of P. graminifolia var. latifolia and addit...

[Genetic variation of some varieties of common juniper Juniperus communis L. inferred from analysis of allozyme loci].

PubMed

Khantemirova, E V; Semerikov, V L

2010-05-01

Using the method of allozyme analysis, genetic variation, diversity, and population structure of Juniperus communis L. var. communis and J. communis L. var. saxatilis Pall. (= J. sibirica Burgsd. = J. nana Wild), growing on the territory of Russia, J. c. var. communis from Sweden, and J. c. var. depressa Pursh from Northern America (Alaska), was investigated. The total level of genetic variation of these varieties was found to be higher than the values obtained for the other conifers. The population samples of J. c. var. depressa from Alaska and J. c. var. saxatilis from Sakhalin were noticeably different from all other populations examined. Between the other samples, no substantial genetic differences were observed. These populations were characterized by weak interpopulation differentiation along with the absence of expressed geographical pattern of the allele frequency spatial distribution. The only exception was the procumbent form of common juniper from the high mountain populations of South and North Ural, which was somewhat different from the others.

Biological activities of organic extracts of four Aureobasidium pullulans varieties isolated from extreme marine and terrestrial habitats.

PubMed

Botić, Tanja; Kralj-Kunčič, Marjetka; Sepčić, Kristina; Batista, Urška; Zalar, Polona; Knez, Željko; Gunde-Cimerman, Nina

2014-01-01

We report on the screening for biological activities of organic extracts from seven strains that represent four varieties of the fungus Aureobasidium pullulans, that is A. pullulans var. melanogenum, A. pullulans var. pullulans, A. pullulans var. subglaciale and A. pullulans var. namibiae. We monitored haemolysis, cytotoxicity, antioxidant capacity and growth inhibition against three bacterial species. The haemolytic activity of A. pullulans var. pullulans EXF-150 strain was due to five different haemolytically active fractions. Extracts from all of the other varieties contained at least one haemolytically active fraction. Short-term exposure of cell lines to these haemolytically active organic extracts resulted in more than 95% cytotoxicity. Strong antioxidant capacity, corresponding to 163.88 μg ascorbic acid equivalent per gram of total solid, was measured in the organic extract of the strain EXF-3382, obtained from A. pullulans var. melanogenum, isolated from the deep sea. Organic extracts from selected varieties of A. pullulans exhibited weak antibacterial activities.

Identification of a Major Dimorphic Region in the Functionally Critical N-Terminal ID1 Domain of VAR2CSA

PubMed Central

Doritchamou, Justin; Sabbagh, Audrey; Jespersen, Jakob S.; Renard, Emmanuelle; Salanti, Ali; Nielsen, Morten A.; Deloron, Philippe; Tuikue Ndam, Nicaise

2015-01-01

The VAR2CSA protein of Plasmodium falciparum is transported to and expressed on the infected erythrocyte surface where it plays a key role in placental malaria (PM). It is the current leading candidate for a vaccine to prevent PM. However, the antigenic polymorphism integral to VAR2CSA poses a challenge for vaccine development. Based on detailed analysis of polymorphisms in the sequence of its ligand-binding N-terminal region, currently the main focus for vaccine development, we assessed var2csa from parasite isolates infecting pregnant women. The results reveal for the first time the presence of a major dimorphic region in the functionally critical N-terminal ID1 domain. Parasite isolates expressing VAR2CSA with particular motifs present within this domain are associated with gravidity- and parasite density-related effects. These observations are of particular interest in guiding efforts with respect to optimization of the VAR2CSA-based vaccines currently under development. PMID:26393516

Effects of seasonal variations on antioxidant activity of pink guava fruits

NASA Astrophysics Data System (ADS)

Ahmad, Haniza; Abdullah, Aminah

2014-09-01

This study aimed to evaluate the effects of seasonal variations during rainy and hot season on antioxidant activity of pink guava fruits in approximately one year duration specifically on November 2012, December 2012, January 2013, March 2013, April 2013, May 2013, July 2013, August 2013 and November 2013. Fruit samples (Sungkai and Semenyih variants) were collected from Sime Darby Beverages plantation located in Sitiawan. The fruits were samples for 9 times from Nov 2012 to Nov 2013 except Feb 2013, Jun 2013, Sept 2013 and Oct 2013. Fruits were peeled, seeded and blended into uniform puree. Samples were then extracted for its antioxidant activity determination using 50% acetone. Antioxidant activity was evaluated using total phenolic compounds (TPC) assay, ferric-reducing antioxidant power assay (FRAP) and 1,1-diphenyl1-2-picrylhydrazyl free radical-scavenging capacity (DPPH). Analysis was conducted using 96-well microplate spectrophotometer UV. The highest TPC result was Semenyih var recorded 2192.80 mg GAE/100g FW whilst Sungkai var 1595.98 mg GAE/100g FW both on July 2013 with rainfall was at the least (45mm) and the lowest for Sungkai var was 792.75 mg GAE/100g FW and 1032.41 mg GAE/100g FW for Semenyih var, both on Nov 2012 with 185mm rainfall. There were significant negative correlation between TPC and rainfall (mm) for both Semenyih var (r = - 0.699, p<0.005, r2 = 0.489) and Sungkai var (r = -0.72, p<0.05, r2 = 0.531). The highest FRAP result (mg TE/100g FW) was 1677.74 for Semenyih var (Aug 2013, rainfall = 160.5mm) and the highest FRAP for Sungkai var was 1104.60 (Jul 2013, rainfall = 45.0mm) whereas the lowest for Semenyih and Sungkai var was 1090.22 (Mar 2013, rainfall = 97.5mm) and 767.88 (Nov 2012, rainfall = 185.50) respectively. There was weak negative correlation between FRAP and rainfall(mm) for both Sungkai var (r = - 0.324, p<0.05, r2 = 0.105) and Semenyih var (r = - 0.362, p<0.05, r2 = 0.132). The highest DPPH for Semenyih var was 88.40% (Aug 2013, rainfall = 160.50mm) whilst Sungkai var was 79.71% (July 2013, rainfall = 45.0mm). There was no significant difference in correlation coefficient of DPPH and rainfall (mm). Meanwhile, there was significant correlation between TPC and FRAP (r = 0.794, p<0.05, r2 = 0.629), TPC and DPPH (r = 0.901,p<0.05, r2= 0.812) and FRAP and DPPH (r = 0.889, p<0.05, r2 = 0.792).

Yersinia enterocolitica: its isolation by cold enrichment from patients and healthy subjects.

PubMed Central

Van Noyen, R; Vandepitte, J; Wauters, G; Selderslaghs, R

1981-01-01

Routine culture and cold enrichment were compared in a prospective study on the isolation of Yersinia enterocolitica from patients with intestinal disease. Healthy controls were examined with the cold enrichment method only. Y enterocolitica was isolated from 5.9% of 1635 patient stools, 3.4% of 206 appendices, and 4.0% of 555 control stools. Serotypes 0:3 and 0:9 were eight times more prevalent in patients than in controls. Other serotypes were twice as prevalent in controls than in patients. Cold enrichment did not significantly increase the recovery of serotypes 0:3 and 0:9 in acute enteritis, but it was responsible for all isolates of the other serotypes. Evidence is presented that the other serotypes are not pathogenic. In patient stools, Y enterocolitica was demonstrated less frequently than Salmonella (9.1%), and more often than Campylobacter jejuni (1.8%) and Shigella (0.1%). PMID:7024325

Transmission probabilities and durations of immunity for three pathogenic group B Streptococcus serotypes

PubMed Central

Percha, Bethany; Newman, M. E. J.; Foxman, Betsy

2012-01-01

Group B Streptococcus (GBS) remains a major cause of neonatal sepsis and is an emerging cause of invasive bacterial infections. The 9 known serotypes vary in virulence, and there is little cross-immunity. Key parameters for planning an effective vaccination strategy, such as average length of immunity and transmission probabilities by serotype, are unknown. We simulated GBS spread in a population using a computational model with parameters derived from studies of GBS sexual transmission in a college dormitory. Here we provide estimates of the duration of immunity relative to the transmission probabilities for the 3 GBS serotypes most associated with invasive disease: Ia, III, and V. We also place upper limits on the durations of immunity for serotype Ia (570 days), III (1125 days) and V (260 days). Better transmission estimates are required to establish the epidemiological parameters of GBS infection and determine the best vaccination strategies to prevent GBS disease. PMID:21605704

Myanmar Dengue Outbreak Associated with Displacement of Serotypes 2, 3, and 4 by Dengue 1

PubMed Central

Thu, Hlaing Myat; Lowry, Kym; Myint, Thein Thein; Shwe, Than Nu; Han, Aye Maung; Khin, Kyu Kyu; Thant, Kyaw Zin; Thein, Soe

2004-01-01

In 2001, Myanmar (Burma) had its largest outbreak of dengue—15,361 reported cases of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), including 192 deaths. That year, 95% of dengue viruses isolated from patients were serotype 1 viruses belonging to two lineages that had diverged from an earlier, now extinct, lineage sometime before 1998. The ratio of DHF to DSS cases in 2001 was not significantly different from that in 2000, when 1,816 cases of DHF/DSS were reported and dengue 1 also was the most frequently isolated serotype. However, the 2001 ratio was significantly higher than that in 1998 (also an outbreak year) and in 1999, when all four serotypes were detected and serotypes 1, 2, and 3 were recovered in similar numbers. The large number of clinical cases in 2001 may have been due, in part, to a preponderance of infections with dengue 1 viruses. PMID:15200847

Discovery of fifth serotype of dengue virus (DENV-5): A new public health dilemma in dengue control.

PubMed

Mustafa, M S; Rasotgi, V; Jain, S; Gupta, V

2015-01-01

Dengue fever is a re-emerging public health problem with two-fifths of the world population being at risk of infection. Till now, dengue fever was believed to be caused by four different serotypes. The fifth variant DENV-5 has been isolated in October 2013. This serotype follows the sylvatic cycle unlike the other four serotypes which follow the human cycle. The likely cause of emergence of the new serotype could be genetic recombination, natural selection and genetic bottlenecks. There is no indication of the presence of DENV-5 in India. Recent clinical trials with the promising Chimerivax tetravalent vaccine suffered a setback. Discovery of DENV-5 and more such sylvatic strains in future may further impede the Dengue Vaccine Initiative. Integrated Vector Management holds the key to sustainable dengue control. Further epidemiological and ecological studies are needed to detect additional sylvatic dengue strains.

Streptococcus pneumoniae: distribution of serotypes and antimicrobial susceptibility in patients with cancer.

PubMed

Soto-Noguerón, Araceli; Carnalla-Barajas, María Noemí; Cornejo-Juárez, Patricia; Volkow-Fernández, Patricia; Velázquez-Meza, María Elena; Echániz-Aviles, Gabriela

2018-01-01

To describe the distribution of pneumococcal serotypes causing infectious diseases in patients with hematological malignancies and solid tumors and their antimicrobial susceptibility before and after introduction of pneumococcal conjugate vaccine (PCV7) in Mexico. Consecutive pneumococcal isolates from hospitalized patients from the SIREVA-network were serotyped using the Quellung reaction and antimicrobial susceptibility was performed using the broth microdilution method. A total of 175 pneumococcal isolates were recovered, 105 from patients with hematological malignancies and 70 with solid tumors. Serotypes 19A (22.7%), 19F (20.4%), and 35B (17.7%) were the most frequent isolates in the first group and serotypes 3 (27.2%) and 19A (28.6%) in the second group. No decreased susceptibility to beta-lactams or TMP/SMX was observed after introduction of PCV7. An increase in non-vaccine types is observed without significate changes in antimicrobial susceptibility after introduction of PCV7.

A simulated metagenomic approach for bacterial serotyping using shotgun genome sequences coupled with O-Antigen gene cluster analysis

USDA-ARS?s Scientific Manuscript database

Background: Accurate determination of food-borne pathogen serotype and genotype information is important for disease surveillance and outbreak source tracking. E. coli serotype O157:H7 and non-O157 of Shiga toxin-producing E. coli (STEC) serogroups, including O26, O45, O103, O111, O121, O145 (top ...

Salmonella species and serotypes isolated from farm animals, animal feed, sewage, and sludge in Saudi Arabia*

PubMed Central

Nabbut, N. H.; Barbour, E. K.; Al-Nakhli, H. M.

1982-01-01

A total of 264 salmonellae representing 65 different species and serotypes were isolated for the first time in Saudi Arabia, from various animal species, animal feed, sewage, and sludge. The six most frequently isolated Salmonella species or serotypes were: livingstone, concord, “S. schottmuelleri” (invalid), lille, S. typhimurium, and cerro. PMID:6983931

Avian Paramyxovirus serotypes circulating in wild bird populations of the Azov-Black Sea region of Ukraine in 2006-2011

USDA-ARS?s Scientific Manuscript database

Over the past 40 years many different paramyxoviruses have been isolated from animals and birds. Paramyxovirus serotypes PMV-1, PMV-2, and PMV-3 are important because they can cause disease in poultry. The goal of our research was to study PMV-1 to PMV-9 paramyxovirus serotypes circulating in diff...

Natural infections with pigeon paramyxovirus serotype 1: Pathologic changes in Eurasian collared-doves (Streptopelia decaocto) and rock pigeons (Columba livia) in the United States

USDA-ARS?s Scientific Manuscript database

Pigeon paramyxovirus serotype 1 (PPMV-1) is a globally distributed, virulent member of the avian paramyxovirus serotype 1 serogroup that causes mortality in columbiformes and poultry. Following introduction into the United States in the mid-1980s, PPMV-1 rapidly spread causing numerous mortality eve...

Completed Genome Sequences of Strains from 36 Serotypes of Salmonella

PubMed Central

Robertson, James; Yoshida, Catherine; Gurnik, Simone; Rankin, Marisa

2018-01-01

ABSTRACT We report here the completed closed genome sequences of strains representing 36 serotypes of Salmonella. These genome sequences will provide useful references for understanding the genetic variation between serotypes, particularly as references for mapping of raw reads or to create assemblies of higher quality, as well as to aid in studies of comparative genomics of Salmonella. PMID:29348347

Microcapsules on Streptococcus mutans serotypes by electron microscopy.

PubMed

Grenier, E M; Gray, R H; Loesche, W J; Eveland, W C

1977-02-01

Extracellular microcapsules have been demonstrated on cells of most serotypes of Streptococcus mutans by electron microscopy, using bacterial strains of the various serotypes and peroxidase labeled or unlabeled immune serum. A correlation was noted between the amount of capsular substance on the strains of S mutans examined and degree of antigenicity as expressed by the indirect fluorescent antibody (FA) title. A serotype d strain was shown to lose both antigenicity as determined by the FA reaction and capsular material as seen by electron microscopy with repeated in vitro passage. When 10% unheated rabbit serum was added to the medium, antigenicity and capsular material were restored.

Isolation and serotyping of Streptococcus mutans from teeth and feces of children.

PubMed

Hamada, S; Masuda, N; Kotani, S

1980-04-01

Streptococcus mutans were detected in the feces from 10 of 29 caries-active patients, aged 4 to 9 years. The percentage of S. mutans to the total counts of facultatively anaerobic streptococci on mitis salivarius agar (Difco Laboratories) varied from 0 to 72.5%. S. mutans were then isolated from dental plaque of sound teeth and carious dentin of the 10 subjects known to harbor S. mutans in the feces. The frequency distribution of various serotypes of these dental and fecal isolates of S. mutans was compared by the immunodiffusion technique. Of the total 1,047 isolates (290 isolates from feces, 289 from dental plaque, and 468 from carious dentin), type c isolates were most prevalent (ca. 66%). Serotype d, e, f, and g isolates were also found but in far lower frequencies. Plural serotypes of S. mutans were occasionally found in dental and fecal samples of a single subject. For two subjects, relatively rare serotypes of S. mutans in the population examined, serotype e, f, or g, were predominantly found in their fecal and dental samples and those of their siblings and mother, suggesting an intrafamilial transmission of S. mutans.

[Dengue virus serotype 1 (DENV-1) from Colombia: its contribution to dengue occurrence in Santander].

PubMed

Ocazionez-Jiménez, Raquel E; Ortiz-Báez, Ayda Susana; Gómez-Rangel, Sergio Yebrail; Miranda-Esquivel, Daniel R

2013-09-01

Between 1998 and 2008 all dengue virus serotypes circulated in the Departamento de Santander, an endemic region in northeastern Colombia. No information is available as to the role of serotype 1 (DENV-1) with respect to epidemiology of dengue. To analyze the relationship between changes in DENV-1 predominance with respect to genetic diversity, prevalence of others serotypes and occurrence of severe dengue. Virus genetic diversity was studied by phylogenetic analysis comparing E gene sequences from 12 viral strains. Data about serotypes predominance obtained in previous studies and official data about dengue incidence were used for analysis. Selected viruses grouped into genotype V together DENV-1 from Latin America countries, and segregation in four lineages was evidenced. Changes in virus predominance coincided with replacement of lineage, increase in prevalence of DENV-2 and DENV-3 and increase of severe dengue. Genetic divergence could have contributed to changes in DENV-1 predominance. The relationship of the virus with DENV-2 and DENV-3 could create scenarios that promote occurrence of severe cases. More studies are required to ascertain the precise role of serotypes in the epidemiology of dengue.

Long-term memory cellular immune response to dengue virus after a natural primary infection.

PubMed

Sierra, Beatríz; García, Gissel; Pérez, Ana B; Morier, Luis; Rodríguez, Rayner; Alvarez, Mayling; Guzmán, María G

2002-06-01

This study was conducted to examine the memory T-cell response to dengue virus 20 years after a primary infection. We took advantage of the exceptional epidemiologic situation in Cuba, where the population initially suffered two large successive epidemics due to dengue virus 1 and 2 respectively over a 4-year period. Thereafter, no dengue virus circulation was subsequently observed, except for the Santiago de Cuba municipality. T-cell response was evaluated in peripheral blood mononuclear cells (PBMCs) from 20 individuals with history of a primary infection by dengue virus 1 or 2. Methods previously shown to induce lymphoproliferation of CD4+ memory T-cell subpopulations were used. We evaluated the proliferative responses generated in those PBMCs after stimulation with dengue virus 1, 2, 3 and 4 antigens in a serotype-specific and serotype-crossreactive way. Serotype-specific and serotype-crossreactive lymphoproliferative responses in all PBMCs donated by dengue immune donors were observed. The serotype-crossreactive response for dengue 2 was stronger than for the rest of the serotypes. This is the first report of cellular memory lymphocyte response specific for dengue virus detected 20 years after a primary infection by dengue.

What’s in a Name? Species-Wide Whole-Genome Sequencing Resolves Invasive and Noninvasive Lineages of Salmonella enterica Serotype Paratyphi B

PubMed Central

Owen, Sian V.; Langridge, Gemma; Connell, Steve; Nair, Satheesh; Reuter, Sandra; Dallman, Timothy J.; Corander, Jukka; Tabing, Kristine C.; Le Hello, Simon; Fookes, Maria; Doublet, Benoît; Zhou, Zhemin; Feltwell, Theresa; Ellington, Matthew J.; Herrera, Silvia; Gilmour, Matthew; Cloeckaert, Axel; Achtman, Mark; Wain, John; De Pinna, Elizabeth; Weill, François-Xavier; Peters, Tansy; Thomson, Nick

2016-01-01

ABSTRACT For 100 years, it has been obvious that Salmonella enterica strains sharing the serotype with the formula 1,4,[5],12:b:1,2—now known as Paratyphi B—can cause diseases ranging from serious systemic infections to self-limiting gastroenteritis. Despite considerable predicted diversity between strains carrying the common Paratyphi B serotype, there remain few methods that subdivide the group into groups that are congruent with their disease phenotypes. Paratyphi B therefore represents one of the canonical examples in Salmonella where serotyping combined with classical microbiological tests fails to provide clinically informative information. Here, we use genomics to provide the first high-resolution view of this serotype, placing it into a wider genomic context of the Salmonella enterica species. These analyses reveal why it has been impossible to subdivide this serotype based upon phenotypic and limited molecular approaches. By examining the genomic data in detail, we are able to identify common features that correlate with strains of clinical importance. The results presented here provide new diagnostic targets, as well as posing important new questions about the basis for the invasive disease phenotype observed in a subset of strains. PMID:27555304

Streptococcus pneumoniae carriage among healthy and sick pediatric patients before the generalized implementation of the 13-valent pneumococcal vaccine in Morocco from 2010 to 2011.

PubMed

Jroundi, Imane; Mahraoui, Chafik; Benmessaoud, Rachid; Moraleda, Cinta; Munoz Almagro, Carmen; Seffar, Meryem; Tligui, Houssain; Kettani, Selma C; Benjelloun, Badr S; Alonso, Pedro L; Bassat, Quique

Nasopharyngeal carriage studies provide insights into the local prevalence of circulating pneumococcal serotypes. These data are critical to vaccination monitoring, as they allow for the prediction and assessment of impact. Very little data are available on the carriage of pneumococcal serotypes in Morocco. Here, we describe the prevalence of Streptococcus pneumoniae carriage and serotype distribution among 697 pediatric patients with ages ranging from 2 to 59 months who were admitted to a Moroccan hospital with severe pneumonia, as well as 195 healthy infants and young children who were recruited at a vaccination clinic. Carriage rates were 40.5% (79/195) for healthy children and 22.8% (159/697) for sick children. The most commonly observed circulating serotypes included 6A, 6B and 19F, all of which are included in the current 13-valent anti-pneumococcal conjugate vaccine that was recently introduced in Morocco. Monitoring of circulating serotypes remains necessary after vaccine introduction to assess whether serotype replacement is occurring. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

Rapid Generation of Replication-Deficient Monovalent and Multivalent Vaccines for Bluetongue Virus: Protection against Virulent Virus Challenge in Cattle and Sheep

PubMed Central

Celma, Cristina C. P.; Boyce, Mark; van Rijn, Piet A.; Eschbaumer, Michael; Wernike, Kerstin; Hoffmann, Bernd; Beer, Martin; Haegeman, Andy; De Clercq, Kris

2013-01-01

Since 1998, 9 of the 26 serotypes of bluetongue virus (BTV) have spread throughout Europe, and serotype 8 has suddenly emerged in northern Europe, causing considerable economic losses, direct (mortality and morbidity) but also indirect, due to restriction in animal movements. Therefore, many new types of vaccines, particularly subunit vaccines, with improved safety and efficacy for a broad range of BTV serotypes are currently being developed by different laboratories. Here we exploited a reverse genetics-based replication-deficient BTV serotype 1 (BTV-1) (disabled infectious single cycle [DISC]) strain to generate a series of DISC vaccine strains. Cattle and sheep were vaccinated with these viruses either singly or in cocktail form as a multivalent vaccine candidate. All vaccinated animals were seroconverted and developed neutralizing antibody responses to their respective serotypes. After challenge with the virulent strains at 21 days postvaccination, vaccinated animals showed neither any clinical reaction nor viremia. Further, there was no interference with protection with a multivalent preparation of six distinct DISC viruses. These data indicate that a very-rapid-response vaccine could be developed based on which serotypes are circulating in the population at the time of an outbreak. PMID:23824810

Rapid generation of replication-deficient monovalent and multivalent vaccines for bluetongue virus: protection against virulent virus challenge in cattle and sheep.

PubMed

Celma, Cristina C P; Boyce, Mark; van Rijn, Piet A; Eschbaumer, Michael; Wernike, Kerstin; Hoffmann, Bernd; Beer, Martin; Haegeman, Andy; De Clercq, Kris; Roy, Polly

2013-09-01

Since 1998, 9 of the 26 serotypes of bluetongue virus (BTV) have spread throughout Europe, and serotype 8 has suddenly emerged in northern Europe, causing considerable economic losses, direct (mortality and morbidity) but also indirect, due to restriction in animal movements. Therefore, many new types of vaccines, particularly subunit vaccines, with improved safety and efficacy for a broad range of BTV serotypes are currently being developed by different laboratories. Here we exploited a reverse genetics-based replication-deficient BTV serotype 1 (BTV-1) (disabled infectious single cycle [DISC]) strain to generate a series of DISC vaccine strains. Cattle and sheep were vaccinated with these viruses either singly or in cocktail form as a multivalent vaccine candidate. All vaccinated animals were seroconverted and developed neutralizing antibody responses to their respective serotypes. After challenge with the virulent strains at 21 days postvaccination, vaccinated animals showed neither any clinical reaction nor viremia. Further, there was no interference with protection with a multivalent preparation of six distinct DISC viruses. These data indicate that a very-rapid-response vaccine could be developed based on which serotypes are circulating in the population at the time of an outbreak.

Binding of glucosyltransferase and glucan synthesis by Streptococcus mutans and other bacteria.

PubMed

Hamada, S; Tai, S; Slade, H D

1978-07-01

Lyophilized and heat-treated cells from the seven serotypes of Streptococcus mutans were examined for their ability to bind added insoluble-product glucosyl-transferase (GTase) and to synthesize cell-associated glucan from [(14)C]sucrose. Lyophilized cells of serotypes a and g did not synthesize any more additional glucan than did the controls after exposure to GTase. These cells, however, synthesized four- to eightfold-greater quantities of glucan than did the cells of the remaining serotypes. Lyophilized cells of serotypes b, c, d, e, and f synthesized two- to threefold-greater quantities of glucan after exposure to GTase than did the controls without added enzyme. Lyophilized cells of serotypes a and g synthesized 6- to 10-fold-greater quantities of glucan than did heat-treated cells of the same strain after binding of GTase. Lyophilized cells of the remaining serotypes synthesized only 1.6- to 3.3-fold-greater quantities of glucan than did the heat-treated cells. These results demonstrate that heat treatment to inactivate cell-associated GTase does not create additional GTase binding sites in S. mutans and that serotypes a and g are considerably more active in cell-associated glucan synthesis than cells of the other five serotypes. Ten species of gram-positive and gram-negative bacteria from five genera which do not produce in vitro plaque synthesized 10- to 100-fold-less glucan than did the S. mutans strains after exposure to GTase. Of these species, S. sanguis, Actinomyces viscosus, and A. naeslundii synthesized the largest quantities of glucan. Three mutant strains of S. mutans which possess a reduced ability for in vitro adherence but do agglutinate with glucan or dextran synthesized only one-third as much glucan after binding of GTase as the control. These results are discussed in relation to in vitro and in vivo plaque development and the agglutination of S. mutans. The results support earlier findings which indicate that the presence of bacterial species other than S. mutans in smooth-surface dental plaque is due in part to contact of the cells with glucan in the developing plaque and not to the binding of cell-free GTase and the in situ synthesis of glucan. The results obtained with these representative strains of the seven serotypes of S. mutans may not apply to the same extent to other strains within the serotypes.

Serotype changes and antimicrobial nonsusceptibility rates of invasive and non-invasive Streptococcus pneumoniae isolates after implementation of 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in Bulgaria.

PubMed

Setchanova, Lena; Murdjeva, Marianna; Stancheva, Iglika; Alexandrova, Alexandra; Sredkova, Maria; Stoeva, Temenuga; Yoneva, Magda; Kurchatova, Anna; Mitov, Ivan

The 10-valent pneumococcal conjugate vaccine (PCV10) has been included in Bulgarian Childhood Immunization Program since 2010. This study aimed to assess serotype distribution and antimicrobial resistance of 198 invasive and non-invasive Streptococcus pneumoniae strains that had been isolated in Bulgaria during 2011-2016 from patients with invasive (IPD) and non-invasive (NIPD) pneumococcal diseases. The most common invasive serotypes were 3 (10.1%), 19F (4.0%), and 7F (3.0%). A significant decrease in the proportion of invasive vaccine types (VTs) from 64.2% to 35.2% was found in comparison with pre-vaccine era. The most common serotypes among middle ear fluids were 3, 19A and 19F (5.6% each), and VTs fell down from 66.4% to 40.0% in post-PCV10 period. Among respiratory isolates, the most prevalent serotypes were some emergent serotypes such as 15A/B/C (5.0%), 19A, and 6C (4.0% each). VTs decreased significantly (16.3%) among vaccinated children compared to unvaccinated children and adults (44.0%). Two non-VTs (19A and 6C) have increased significantly more (p<0.05) in vaccinated children than in unvaccinated patients. The rates of antibiotic nonsusceptible S. pneumoniae in Bulgaria remained high in post-PCV10 era. Among all source of isolates, antimicrobial nonsusceptibility rates were: oral penicillin - 46.5%, trimethoprim-sulfamethoxazole - 45.4%, erythromycin - 43.9%, tetracycline - 37.4%, and multidrug-resistance (MDR) was 44%. The most common MDR serotypes were 19F, 19A, 6A/C, 15A/B/C and 23A. Our results proved that PCV10 vaccination substantially reduced VTs pneumococcal IPD and NIPD. There has been a shift in the distribution of S. pneumoniae serotypes mostly in vaccinated children but also in the whole population and strong serotype-specific antibiotic resistance was observed after vaccine implementation. Therefore, it is important to continue monitoring serotype changes and pneumococcal resistance among all patient ages in addition to aid in determining the long-term effectiveness of PCV10 interventions. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

Direct Comparison of Immunogenicity Induced by 10- or 13-Valent Pneumococcal Conjugate Vaccine around the 11-Month Booster in Dutch Infants

PubMed Central

Wijmenga-Monsuur, Alienke J.; van Westen, Els; Knol, Mirjam J.; Jongerius, Riet M. C.; Zancolli, Marta; Goldblatt, David; van Gageldonk, Pieter G. M.; Tcherniaeva, Irina; Berbers, Guy A. M.; Rots, Nynke Y.

2015-01-01

Background & Aims Since 2009/10, a 10- and a 13-valent pneumococcal conjugate vaccine (PCV) are available, but only the 10-valent vaccine is now being used for the children in the Netherlands. As the vaccines differ in number of serotypes, antigen concentration, and carrier proteins this study was designed to directly compare quantity and quality of the antibody responses induced by PCV10 and PCV13 before and after the 11-month booster. Methods Dutch infants (n = 132) were immunized with either PCV10 or PCV13 and DTaP-IPV-Hib-HepB at the age of 2, 3, 4 and 11 months. Blood samples were collected pre-booster and post-booster at one week and one month post-booster for quantitative and qualitative immunogenicity against 13 pneumococcal serotypes, as well as quantitative immunogenicity against diphtheria, tetanus, pertussis and Haemophilus influenzae type b. We compared immunogenicity induced by PCV13 and PCV10 for their ten shared serotypes. Results One month post-booster, pneumococcal serotype-specific IgG geometric mean concentrations (GMCs) for the PCV13 group were higher compared with the PCV10 group for six serotypes, although avidity was lower. Serotype 19F showed the most distinct difference in IgG and, in contrast to other serotypes, its avidity was higher in the PCV13 group. One week post-booster, opsonophagocytosis for serotype 19F did not differ significantly between the PCV10- and the PCV13 group. Conclusion Both PCV10 and PCV13 were immunogenic and induced a booster response. Compared to the PCV10 group, the PCV13 group showed higher levels for serotype 19F GMCs and avidity, pre- as well as post-booster, although opsonophagocytosis did not differ significantly between groups. In our study, avidity is not correlated to opsonophagocytotic activity (OPA) and correlations between IgG and OPA differ per serotype. Therefore, besides assays to determine IgG GMCs, assays to detect opsonophagocytotic activity, i.e., the actual killing of the pneumococcus, are important for PCV evaluation. How differences between the two vaccines relate to long-term protection requires further investigation. Trial Registration www.trialregister.nl NTR3069 PMID:26658902

Effect of Serotype on Pneumococcal Competition in a Mouse Colonization Model.

PubMed

Trzciński, Krzysztof; Li, Yuan; Weinberger, Daniel M; Thompson, Claudette M; Cordy, Derrick; Bessolo, Andrew; Malley, Richard; Lipsitch, Marc

2015-09-15

Competitive interactions between Streptococcus pneumoniae strains during host colonization could influence the serotype distribution in nasopharyngeal carriage and pneumococcal disease. We evaluated the competitive fitness of strains of serotypes 6B, 14, 19A, 19F, 23F, and 35B in a mouse model of multiserotype carriage. Isogenic variants were constructed using clinical strains as the capsule gene donors. Animals were intranasally inoculated with a mixture of up to six pneumococcal strains of different serotypes, with separate experiments involving either clinical isolates or isogenic capsule-switch variants of clinical strain TIGR4. Upper-respiratory-tract samples were repeatedly collected from animals in order to monitor changes in the serotype ratios using quantitative PCR. A reproducible hierarchy of capsular types developed in the airways of mice inoculated with multiple strains. Serotype ranks in this hierarchy were similar among pneumococcal strains of different genetic backgrounds in different strains of mice and were not altered when tested under a range of host conditions. This rank correlated with the measure of the metabolic cost of capsule synthesis and in vitro measure of pneumococcal cell surface charge, both parameters considered to be predictors of serotype-specific fitness in carriage. This study demonstrates the presence of a robust competitive hierarchy of pneumococcal serotypes in vivo that is driven mainly, but not exclusively, by the capsule itself. Streptococcus pneumoniae (pneumococcus) is the leading cause of death due to respiratory bacterial infections but also a commensal frequently carried in upper airways. Available vaccines induce immune responses against polysaccharides coating pneumococcal cells, but with over 90 different capsular types (serotypes) identified, they can only target strains of the selected few serotypes most prevalent in disease. Vaccines not only protect vaccinated individuals against disease but also protect by reducing carriage of vaccine-targeted strains to induce herd effects across whole populations. Unfortunately, reduction in the circulation of vaccine-type strains is offset by increase in carriage and disease from nonvaccine strains, indicating the importance of competitive interactions between pneumococci in shaping the population structure of this pathogen. Here, we showed that the competitive ability of pneumococcal strains to colonize the host strongly depends on the type of capsular polysaccharide expressed by pneumococci and only to a lesser degree on strain or host genetic backgrounds or on variation in host immune responses. Copyright © 2015 Trzciński et al.

Distribution Management System Volt/VAR Evaluation | Grid Modernization |

Science.gov Websites

NREL Distribution Management System Volt/VAR Evaluation Distribution Management System Volt/VAR Evaluation This project involves building a prototype distribution management system testbed that links a GE Grid Solutions distribution management system to power hardware-in-the-loop testing. This setup is

Ultrastructural Effects of Bacillus thuringiensis var. san diego on Midgut Cells of the Cottonwood Leaf Beetle1

Treesearch

Leah S. Bauer; Stuart H. Pankratz

1992-01-01

Sequential observations of the ultrastructural effects of Bacillus thuringiensis var. san diego were made on midgut epithelial cells of the cottonwood leaf beetle, Chrysomela scripta F. Larvae imbibed a droplet of B. thuringiensis var. san diego containing endotoxin and live...

Antibacterial activity of Mediterranean Oyster mushrooms, species of genus Pleurotus (higher Basidiomycetes).

PubMed

Schillaci, Domenico; Arizza, Vincenzo; Gargano, Maria Letizia; Venturella, Giuseppe

2013-01-01

Extracts of the Mediterranean culinary-medicinal Oyster mushrooms Pleurotus eryngii var. eryngii, P. eryngii var. ferulae, P. eryngii var. elaeoselini, and P. nebrodensis were tested for their in vitro growth inhibitory activity against a group of bacterial reference strains of medical relevance: Staphylococcus aureus ATCC 25923, S. epidermidis RP62A, Pseudomonas aeruginosa ATCC 15442, and Escherichia coli ATCC10536. All of the Pleurotus species analyzed inhibited the tested microorganisms in varying degrees. The data included in this paper for P. nebrodensis and P. eryngii var. elaeoselinii are new reports.

Rolling Contact Fatigue Life and Spall Propagation Characteristics of AISI M50, M50 NiL, and AISI 52100. Part 3. Metallurgical Examination (Preprint)

DTIC Science & Technology

2009-10-01

bearing materials, namely AISI 52100, VIM-VAR M50 , and VIM-VAR M50 NiL steels . While...propagation characteristics of three bearing materials, namely AISI 52100, VIM-VAR M50 , and VIM-VAR M50 NiL steels . While there is substantial prior work...deformation from run in. Residual stress profiles for bearing 075B are shown in Figure 3. The bearing is made from M50 steel and the spall

Antifungal compounds from Zanthoxylum chiloperone var. angustifolium.

PubMed

Thouvenel, Céline; Gantier, Jean-Charles; Duret, Philippe; Fourneau, Christophe; Hocquemiller, Reynald; Ferreira, Maria-Elena; Rojas de Arias, Antonieta; Fournet, Alain

2003-06-01

An alkaloidal extract of the stem barks of Zanthoxylum chiloperone var. angustifolium exhibited antifungal activity against Candida albicans, Aspergillus fumigatus and Trichophyton mentagrophytes var. interdigitale using a TLC bioautographic method. Bioassay-guided fractionation of this extract resulted in the isolation of two active compounds identi fi ed as canthin-6-one and 5-methoxycanthin-6-one. Canthin-6-one exhibited a broad spectrum of activities against Aspergillus fumigatus, A. niger, A. terreus, Candida albicans, C. tropicalis, C. glabrata, Cryptococcus neoformans, Geotrichum candidum, Saccharomyces cerevisiae, Trichosporon beigelii, Trichosporon cutaneum and Trichophyton mentagrophytes var. interdigitale with MICs values between 5.3 and 46 micro mol/L. 5-methoxy-canthin-6-one was active against only Trichophyton mentagrophytes var. interdigitale with a MIC value of 12.3 micro mol/L. Copyright 2003 John Wiley & Sons, Ltd.

Differential recognition of terminal extracellular Plasmodium falciparum VAR2CSA domains by sera from multigravid, malaria-exposed Malian women.

PubMed

Travassos, Mark A; Coulibaly, Drissa; Bailey, Jason A; Niangaly, Amadou; Adams, Matthew; Nyunt, Myaing M; Ouattara, Amed; Lyke, Kirsten E; Laurens, Matthew B; Pablo, Jozelyn; Jasinskas, Algis; Nakajima, Rie; Berry, Andrea A; Takala-Harrison, Shannon; Kone, Abdoulaye K; Kouriba, Bourema; Rowe, J Alexandra; Doumbo, Ogobara K; Thera, Mahamadou A; Laufer, Miriam K; Felgner, Philip L; Plowe, Christopher V

2015-06-01

The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family mediates parasite sequestration in small capillaries through tissue-specific cytoadherence. The best characterized of these proteins is VAR2CSA, which is expressed on the surface of infected erythrocytes that bind to chondroitin sulfate in the placental matrix. Antibodies to VAR2CSA prevent placental cytoadherence and protect against placental malaria. The size and complexity of the VAR2CSA protein pose challenges for vaccine development, but smaller constitutive domains may be suitable for subunit vaccine development. A protein microarray was printed to include five overlapping fragments of the 3D7 VAR2CSA extracellular region. Malian women with a history of at least one pregnancy had antibody recognition of four of these fragments and had stronger reactivity against the two distal fragments than did nulliparous women, children, and men from Mali, suggesting that the C-terminal extracellular VAR2CSA domains are a potential focus of protective immunity. With carefully chosen sera from longitudinal studies of pregnant women, this approach has the potential to identify seroreactive VAR2CSA domains associated with protective immunity against pregnancy-associated malaria. © The American Society of Tropical Medicine and Hygiene.

Data assimilation and prognostic whole ice sheet modelling with the variationally derived, higher order, open source, and fully parallel ice sheet model VarGlaS

NASA Astrophysics Data System (ADS)

Brinkerhoff, D. J.; Johnson, J. V.

2013-07-01

We introduce a novel, higher order, finite element ice sheet model called VarGlaS (Variational Glacier Simulator), which is built on the finite element framework FEniCS. Contrary to standard procedure in ice sheet modelling, VarGlaS formulates ice sheet motion as the minimization of an energy functional, conferring advantages such as a consistent platform for making numerical approximations, a coherent relationship between motion and heat generation, and implicit boundary treatment. VarGlaS also solves the equations of enthalpy rather than temperature, avoiding the solution of a contact problem. Rather than include a lengthy model spin-up procedure, VarGlaS possesses an automated framework for model inversion. These capabilities are brought to bear on several benchmark problems in ice sheet modelling, as well as a 500 yr simulation of the Greenland ice sheet at high resolution. VarGlaS performs well in benchmarking experiments and, given a constant climate and a 100 yr relaxation period, predicts a mass evolution of the Greenland ice sheet that matches present-day observations of mass loss. VarGlaS predicts a thinning in the interior and thickening of the margins of the ice sheet.

Working alliance inventory applied to virtual and augmented reality (WAI-VAR): psychometrics and therapeutic outcomes

PubMed Central

Miragall, Marta; Baños, Rosa M.; Cebolla, Ausiàs; Botella, Cristina

2015-01-01

This study examines the psychometric properties of the Working Alliance Inventory-Short (WAI-S) adaptation to Virtual Reality (VR) and Augmented Reality (AR) therapies (WAI-VAR). The relationship between the therapeutic alliance (TA) with VR and AR and clinically significant change (CSC) is also explored. Seventy-five patients took part in this study (74.7% women, Mage = 34.41). Fear of flying and adjustment disorder patients received VR therapy, and cockroach phobia patients received AR therapy. Psychometric properties, CSC, one-way ANOVA, Spearman’s Correlations and Multiple Regression were calculated. The WAI-VAR showed a unidimensional structure, high internal consistency and adequate convergent validity. “Not changed” patients scored lower on the WAI-VAR than “improved” and “recovered” patients. Correlation between the WAI-VAR and CSC was moderate. The best fitting model for predicting CSC was a linear combination of the TA with therapist (WAI-S) and the TA with VR and AR (WAI-VAR), due to the latter variable slightly increased the percentage of variability accounted for in CSC. The WAI-VAR is the first validated instrument to measure the TA with VR and AR in research and clinical practice. This study reveals the importance of the quality of the TA with technologies in achieving positive outcomes in the therapy. PMID:26500589

Working alliance inventory applied to virtual and augmented reality (WAI-VAR): psychometrics and therapeutic outcomes.

PubMed

Miragall, Marta; Baños, Rosa M; Cebolla, Ausiàs; Botella, Cristina

2015-01-01

This study examines the psychometric properties of the Working Alliance Inventory-Short (WAI-S) adaptation to Virtual Reality (VR) and Augmented Reality (AR) therapies (WAI-VAR). The relationship between the therapeutic alliance (TA) with VR and AR and clinically significant change (CSC) is also explored. Seventy-five patients took part in this study (74.7% women, M age = 34.41). Fear of flying and adjustment disorder patients received VR therapy, and cockroach phobia patients received AR therapy. Psychometric properties, CSC, one-way ANOVA, Spearman's Correlations and Multiple Regression were calculated. The WAI-VAR showed a unidimensional structure, high internal consistency and adequate convergent validity. "Not changed" patients scored lower on the WAI-VAR than "improved" and "recovered" patients. Correlation between the WAI-VAR and CSC was moderate. The best fitting model for predicting CSC was a linear combination of the TA with therapist (WAI-S) and the TA with VR and AR (WAI-VAR), due to the latter variable slightly increased the percentage of variability accounted for in CSC. The WAI-VAR is the first validated instrument to measure the TA with VR and AR in research and clinical practice. This study reveals the importance of the quality of the TA with technologies in achieving positive outcomes in the therapy.

Evaluation of morpho-anatomical and chemical differences between varieties of the medicinal plant Casearia sylvestris Swartz.

PubMed

Claudino, Josiane C; Sacramento, Luis V S do; Koch, Ingrid; Santos, Helen A; Cavalheiro, Alberto J; Tininis, Aristeu G; Santos, André G dos

2013-01-01

Casearia sylvestris Swartz (Salicaceae) has been used in traditional medicine and its leaf extracts have been exhibited important pharmacological activities. The species presents morphological, chemical and genetic variation. Two varieties are considered due external morphological differences: C. sylvestris var. sylvestris and var. lingua. There are difficulties in definition of these varieties. The objective of this work is to evaluate chemical and morpho-anatomical differences between C. sylvestris varieties that can be applied in their distinction for pharmaceutical or botanical purposes. Transverse and paradermic sections of leaves were prepared for morpho-anatomical, histochemical and quantitative microscopy (stomatal and palisade index) analyses. Diterpene profiles of the specimens were obtained by HPLC-DAD and TLC. Morpho-anatomical analyses demonstrated significant differences between the varieties only in paradermic sections: var. sylvestris--polygonal epidermic cell walls and hypostomatic; var. lingua--rounded epidermic cell walls and amphistomatic. No differences were observed for stomatal index; palisade index was found 2.8 for var. lingua and 3.9 for var. sylvestris. Chromatographic analyses confirmed previous results demonstrating that diterpene profile in varieties differs, with predominance of these metabolites in var. sylvestris. In conclusion, this work indicates that chromatographic analysis besides morpho-anatomical analysis can be applied in distinction of C. sylvestris varieties.

In vitro antioxidant and anticancer effects of solvent fractions from Prunella vulgaris var. lilacina.

PubMed

Hwang, Yu-Jin; Lee, Eun-Ju; Kim, Haeng-Ran; Hwang, Kyung-A

2013-11-09

Recently, considerable attention has been focused on exploring the potential antioxidant properties of plant extracts or isolated products of plant origin. Prunella vulgaris var. lilacina is widely distributed in Korea, Japan, China, and Europe, and it continues to be used to treat inflammation, eye pain, headache, and dizziness. However, reports on the antioxidant activities of P. vulgaris var. lilacina are limited, particularly concerning the relationship between its phenolic content and antioxidant capacity. In this study, we investigated the antioxidant and anticancer activities of an ethanol extract from P. vulgaris var. lilacina and its fractions. Dried powder of P. vulgaris var. lilacina was extracted with ethanol, and the extract was fractionated to produce the hexane fraction, butanol fraction, chloroform fraction and residual water fraction. The phenolic content was assayed using the Folin-Ciocalteu colorimetric method. Subsequently, the antioxidant activities of the ethanol extract and its fractions were analyzed employing various antioxidant assay methods including DPPH, FRAP, ABTS, SOD activity and production of reactive oxygen species. Additionally, the extract and fractions were assayed for their ability to exert cytotoxic activities on various cancer cells using the MTT assay. We also investigated the expression of genes associated with apoptotic cell death by RT-PCR. The total phenolic contents of the ethanol extract and water fraction of P. vulgaris var. lilacina were 303.66 and 322.80 mg GAE/g dry weight (or fractions), respectively. The results showed that the ethanol extract and the water fraction of P. vulgaris var. lilacina had higher antioxidant content than other solvent fractions, similar to their total phenolic content. Anticancer activity was also tested using the HepG2, HT29, A549, MKN45 and HeLa cancer cell lines. The results clearly demonstrated that the P. vulgaris var. lilacina ethanol extract induced significant cytotoxic effects on the various cancer cell lines, and these effects were stronger than those induced by the P. vulgaris var. lilacina solvent fractions. We also investigated the expression of genes associated with apoptotic cell death. We confirmed that the P. vulgaris var. lilacina ethanol extract and water fraction significantly increased the expression of p53, Bax and Fas. These results suggest that the ethanol extract from P. vulgaris var. lilacina and its fractions could be applied as natural sources of antioxidants and anticancer activities in food and in the pharmaceutical industry.

Classification tree and minimum-volume ellipsoid analyses of the distribution of ponderosa pine in the western USA

USGS Publications Warehouse

Norris, Jodi R.; Jackson, Stephen T.; Betancourt, Julio L.

2006-01-01

Aim? Ponderosa pine (Pinus ponderosa Douglas ex Lawson & C. Lawson) is an economically and ecologically important conifer that has a wide geographic range in the western USA, but is mostly absent from the geographic centre of its distribution - the Great Basin and adjoining mountain ranges. Much of its modern range was achieved by migration of geographically distinct Sierra Nevada (P. ponderosa var. ponderosa) and Rocky Mountain (P. ponderosa var. scopulorum) varieties in the last 10,000 years. Previous research has confirmed genetic differences between the two varieties, and measurable genetic exchange occurs where their ranges now overlap in western Montana. A variety of approaches in bioclimatic modelling is required to explore the ecological differences between these varieties and their implications for historical biogeography and impending changes in western landscapes. Location? Western USA. Methods? We used a classification tree analysis and a minimum-volume ellipsoid as models to explain the broad patterns of distribution of ponderosa pine in modern environments using climatic and edaphic variables. Most biogeographical modelling assumes that the target group represents a single, ecologically uniform taxonomic population. Classification tree analysis does not require this assumption because it allows the creation of pathways that predict multiple positive and negative outcomes. Thus, classification tree analysis can be used to test the ecological uniformity of the species. In addition, a multidimensional ellipsoid was constructed to describe the niche of each variety of ponderosa pine, and distances from the niche were calculated and mapped on a 4-km grid for each ecological variable. Results? The resulting classification tree identified three dominant pathways predicting ponderosa pine presence. Two of these three pathways correspond roughly to the distribution of var. ponderosa, and the third pathway generally corresponds to the distribution of var. scopulorum. The classification tree and minimum-volume ellipsoid model show that both varieties have very similar temperature limitations, although var. ponderosa is more limited by the temperature extremes of the continental interior. The precipitation limitations of the two varieties are seasonally different, with var. ponderosa requiring significant winter moisture and var. scopulorum requiring significant summer moisture. Great Basin mountain ranges are too cold at higher elevations to support either variety of ponderosa pine, and at lower elevations are too dry in summer for var. scopulorum and too dry in winter for var. ponderosa. Main conclusions? The classification tree analysis indicates that var. ponderosa is ecologically as well as genetically distinct from var. scopulorum. Ecological differences may maintain genetic separation in spite of a limited zone of introgression between the two varieties in western Montana. Two hypotheses about past and future movements of ponderosa pine emerge from our analyses. The first hypothesis is that, during the last glacial period, colder and/or drier summers truncated most of the range of var. scopulorum in the central Rockies, but had less dramatic effects on the more maritime and winter-wet distribution of var. ponderosa. The second hypothesis is that, all other factors held constant, increasing summer temperatures in the future should produce changes in the distribution of var. scopulorum that are likely to involve range expansions in the central Rockies with the warming of mountain ranges currently too cold but sufficiently wet in summer for var. scopulorum. Finally, our results underscore the growing need to focus on genotypes in biogeographical modelling and ecological forecasting.

Dengue envelope-based 'four-in-one' virus-like particles produced using Pichia pastoris induce enhancement-lacking, domain III-directed tetravalent neutralising antibodies in mice.

PubMed

Rajpoot, Ravi Kant; Shukla, Rahul; Arora, Upasana; Swaminathan, Sathyamangalam; Khanna, Navin

2018-06-05

Dengue is a significant public health problem worldwide, caused by four antigenically distinct mosquito-borne dengue virus (DENV) serotypes. Antibodies to any given DENV serotype which can afford protection against that serotype tend to enhance infection by other DENV serotypes, by a phenomenon termed antibody-dependent enhancement (ADE). Antibodies to the viral pre-membrane (prM) protein have been implicated in ADE. We show that co-expression of the envelope protein of all four DENV serotypes, in the yeast Pichia pastoris, leads to their co-assembly, in the absence of prM, into tetravalent mosaic VLPs (T-mVLPs), which retain the serotype-specific antigenic integrity and immunogenicity of all four types of their monomeric precursors. Following a three-dose immunisation schedule, the T-mVLPs elicited EDIII-directed antibodies in mice which could neutralise all four DENV serotypes. Importantly, anti-T-mVLP antibodies did not augment sub-lethal DENV-2 infection of dengue-sensitive AG129 mice, based on multiple parameters. The 'four-in-one' tetravalent T-mVLPs possess multiple desirable features which may potentially contribute to safety (non-viral, prM-lacking and ADE potential-lacking), immunogenicity (induction of virus-neutralising antibodies), and low cost (single tetravalent immunogen produced using P. pastoris, an expression system known for its high productivity using simple inexpensive media). These results strongly warrant further exploration of this vaccine candidate.

Pediatric Invasive Pneumococcal Disease in Guatemala City: Importance of Serotype 2.

PubMed

Gaensbauer, James T; Asturias, Edwin J; Soto, Monica; Holt, Elizabeth; Olson, Daniel; Halsey, Neal A

2016-05-01

To inform estimations of the potential impact of recently introduced pneumococcal conjugate vaccine (PCV), we report results of 11 years of pre-PCV surveillance for invasive pneumococcal disease (IPD) among children in Guatemala City. Cases of IPD in children younger than 5 years were identified by active surveillance at 3 referral hospitals in Guatemala City from October 1996 through 2007. Clinical and demographic data were obtained, and isolates of Streptococcus pneumoniae from normally sterile sites were serotyped using latex agglutination and confirmed by Quellung reaction. Four hundred fifty-two cases of IPD were identified with a case fatality rate of 21%. Meningitis was the most common cause of death (77% of all deaths) and occurred more often in infancy (median age 5 months) than other clinical syndromes. Of the 137 isolates serotyped, type 1 (26 cases, 17%), type 2 (25 cases, 16%) and type 5 (18 cases, 12%) were the most common. Serotype 2 was associated with a higher case fatality rate (28%), higher rate of meningitis (68%) and occurred in younger infants (median age, 3.5 months) than other common serotypes. Recently introduced PCV13 includes 73% of observed serotypes in the study. Infants with IPD presented at a young age. Serotype 2, rarely reported as a significant cause of IPD and not included in available PCVs, was a common cause of disease in this population. PCV13 introduction in Guatemala, begun in 2013, may not have as great an impact in disease reduction as has been observed in other countries.

The small regulatory RNA FasX enhances group A Streptococcus virulence and inhibits pilus expression via serotype-specific targets

PubMed Central

Danger, Jessica L.; Cao, Tram N.; Cao, Tran H.; Sarkar, Poulomee; Treviño, Jeanette; Pflughoeft, Kathryn J.; Sumby, Paul

2015-01-01

Summary Bacterial pathogens commonly show intra-species variation in virulence factor expression and often this correlates with pathogenic potential. The group A Streptococcus (GAS) produces a small regulatory RNA (sRNA), FasX, which regulates the expression of pili and the thrombolytic agent streptokinase. As GAS serotypes are polymorphic regarding (a) FasX abundance, (b) the fibronectin, collagen, T-antigen (FCT) region of the genome, which contains the pilus genes (nine different FCT-types), and (c) the streptokinase-encoding gene (ska) sequence (two different alleles), we sought to test whether FasX regulates pilus and streptokinase expression in a serotype-specific manner. Parental, fasX mutant, and complemented derivatives of serotype M1 (ska-2, FCT-2), M2 (ska-1, FCT-6), M6 (ska-2, FCT-1), and M28 (ska-1, FCT-4) isolates were compared. While FasX reduced pilus expression in each serotype, the molecular basis differed, as FasX bound, and inhibited the translation of, different FCT-region mRNAs. FasX enhanced streptokinase expression in each serotype, although the degree of regulation varied. Finally, we established that the regulation afforded by FasX enhances GAS virulence, assessed by a model of bacteremia using human plasminogen-expressing mice. Our data are the first to identify and characterize serotype-specific regulation by an sRNA in GAS, and to show an sRNA directly contributes to GAS virulence. PMID:25586884

Dengue serotype-specific immune response in Aedes aegypti and Aedes albopictus

PubMed Central

Smartt, Chelsea T; Shin, Dongyoung; Alto, Barry W

2017-01-01

BACKGROUND Dengue viruses (DENV) are considered one of the most important emerging pathogens and dengue disease is a global health threat. The geographic expansion of dengue viruses has led to co-circulation of all four dengue serotypes making it imperative that new DENV control strategies be devised. OBJECTIVES Here we characterize dengue serotype-specific innate immune responses in Aedes aegypti and Aedes albopictus using DENV from Puerto Rico (PR). METHODS Ae. aegypti and Ae. albopictus were infected with dengue serotype 1 and 2 isolated from Puerto Rico. DENV infected mosquito samples were collected and temporal change in expression of selected innate immune response pathway genes analyzed by quantitative real time PCR. FINDINGS The Toll pathway is involved in anti-dengue response in Ae. aegypti, and Ae. albopictus. Infections with PR DENV- 1 elicited a stronger response from genes of the Toll immune pathway than PR DENV-2 in Ae. aegypti but in infected Ae. albopictus expression of Toll pathway genes tended to be similar between the serotypes. Two genes (a ribosomal S5 protein gene and a nimrod-like gene) from Ae. albopictus were expressed in response to DENV. MAIN CONCLUSIONS These studies revealed a role for antiviral genes in DENV serotype-specific interactions with DENV vectors, demonstrated that infections with DENV-2 can modulate the Toll immune response pathway in Ae. aegypti and elucidated candidate molecules that might be used to interfere with serotype specific vector-virus interactions. PMID:29211244

A longitudinal study of Salmonella from snakes used in a public outreach program.

PubMed

Goupil, Brad A; Trent, Ava M; Bender, Jeff; Olsen, Karen E; Morningstar, Brenda R; Wünschmann, Arno

2012-12-01

Snakes are considered to be a source of Salmonella infection for humans, but little is known about the actual serotype prevalence in healthy snakes over time. Twelve snakes involved in a public outreach program, representing seven different species, were tested weekly for shedding of Salmonella sp. over a period of 10 consecutive weeks. The snakes were housed in close proximity but in separate exhibits. Fresh fecal samples (when available) or cloacal swabs were cultured for Salmonella sp., and subsequent Salmonella isolates were serotyped. As representatives of the feed source, the feces of two mice and the intestines of one rat were cultured weekly. Fecal samples from 11 of the 12 snakes were positive for Salmonella at least once. Seven (58%) of 12 snakes were culture positive five times or more. The weekly prevalence of Salmonella shedding varied between 25% and 66%. Two or more different serotypes were isolated from nine snakes over time; however, a predominant serotype was generally isolated from each of these snakes. Altogether 15 different serotypes were identified. Serotypes of public health concern included Newport, Oranienburg, and Muenchen. Two samples from feeder rodents were positive for Salmonella. The results are consistent with previous studies showing high intestinal colonization rates with Salmonella sp. in snakes. Frequent and intermittent shedding of multiple serotypes was evident. Feeder rodents might serve as a source for intestinal colonization. Appropriate handling protocols should be implemented for all reptiles associated with public outreach programs to minimize risk of Salmonella transmission to the public.

Phylogenetics and evolution of Su(var)3-9 SET genes in land plants: rapid diversification in structure and function.

PubMed

Zhu, Xinyu; Ma, Hong; Chen, Zhiduan

2011-03-09

Plants contain numerous Su(var)3-9 homologues (SUVH) and related (SUVR) genes, some of which await functional characterization. Although there have been studies on the evolution of plant Su(var)3-9 SET genes, a systematic evolutionary study including major land plant groups has not been reported. Large-scale phylogenetic and evolutionary analyses can help to elucidate the underlying molecular mechanisms and contribute to improve genome annotation. Putative orthologs of plant Su(var)3-9 SET protein sequences were retrieved from major representatives of land plants. A novel clustering that included most members analyzed, henceforth referred to as core Su(var)3-9 homologues and related (cSUVHR) gene clade, was identified as well as all orthologous groups previously identified. Our analysis showed that plant Su(var)3-9 SET proteins possessed a variety of domain organizations, and can be classified into five types and ten subtypes. Plant Su(var)3-9 SET genes also exhibit a wide range of gene structures among different paralogs within a family, even in the regions encoding conserved PreSET and SET domains. We also found that the majority of SUVH members were intronless and formed three subclades within the SUVH clade. A detailed phylogenetic analysis of the plant Su(var)3-9 SET genes was performed. A novel deep phylogenetic relationship including most plant Su(var)3-9 SET genes was identified. Additional domains such as SAR, ZnF_C2H2 and WIYLD were early integrated into primordial PreSET/SET/PostSET domain organization. At least three classes of gene structures had been formed before the divergence of Physcomitrella patens (moss) from other land plants. One or multiple retroposition events might have occurred among SUVH genes with the donor genes leading to the V-2 orthologous group. The structural differences among evolutionary groups of plant Su(var)3-9 SET genes with different functions were described, contributing to the design of further experimental studies.

Prevalence of Streptococcus pneumoniae serotype 6C among invasive and carriage isolates in metropolitan Salvador, Brazil from 1996-2007

PubMed Central

Campos, Leila C.; Carvalho, Maria da Gloria S.; Beall, Bernard W.; Cordeiro, Soraia M.; Takahashi, Daniele; Reis, Mitermayer G.; Ko, Albert I.; Reis, Joice N.

2009-01-01

The newly described Streptococcus pneumoniae serotype 6C accounted for 2.3% (16/709) of meningitis cases and 3.2% (3/95) of nasopharyngeal isolates from healthy individuals in Brazil. The strains were multidrug resistant (18.8%) and genetically diverse. Despite low serotype 6C prevalence, continuous surveillance is necessary to guide vaccine strategies. PMID:19709842

Whole genome sequencing and phylogenetic analysis of Bluetongue virus serotype 2 strains isolated in the Americas including a novel strain from the western United States

USDA-ARS?s Scientific Manuscript database

Bluetongue is caused by an arbovirus which produces widespread edema and tissue necrosis in domestic and wild ruminants that can be fatal. Bluetongue virus serotypes 10, 11, 13, and 17 are typically found throughout the United States (US), while serotype 2 was previously only detected in the southea...

Isolation, characterization and comparative genomics of bacteriophage SfIV: a novel serotype converting phage from Shigella flexneri

PubMed Central

2013-01-01

Background Shigella flexneri is the major cause of shigellosis in the developing countries. The O-antigen component of the lipopolysaccharide is one of the key virulence determinants required for the pathogenesis of S. flexneri. The glucosyltransferase and/or acetyltransferase genes responsible for the modification of the O-antigen are encoded by temperate serotype converting bacteriophage present in the S. flexneri genome. Several serotype converting phages have previously been isolated and characterized, however, attempts to isolate a serotype converting phage which encodes the modification genes of serotypes 4a strain have not been successful. Results In this study, a novel temperate serotype converting bacteriophage SfIV was isolated. Lysogenisation of phage SfIV converted serotype Y strain to serotype 4a. Electron microscopy indicated that SfIV belongs to Myoviridae family. The 39,758 bp genome of phage SfIV encompasses 54 open reading frames (orfs). Protein level comparison of SfIV with other serotype converting phages of S. flexneri revealed that SfIV is similar to phage SfII and SfV. The comparative analysis also revealed that SfIV phage contained five proteins which were not found in any other phages of S. flexneri. These proteins were: a tail fiber assembly protein, two hypothetical proteins with no clear function, and two other unknown proteins which were encoded by orfs present on a moron, that presumably got introduced in SfIV genome from another species via a transposon. These unique proteins of SfIV may play a role in the pathogenesis of the host. Conclusions This study reports the isolation and complete genome sequence analysis of bacteriophage SfIV. The SfIV phage has a host range significantly different from the other phages of Shigella. Comparative genome analysis identified several proteins unique to SfIV, which may potentially be involved in the survival and pathogenesis of its host. These findings will further our understanding on the evolution of these phages, and will also facilitate studies on development of new phage vectors and therapeutic agents to control infections caused by S. flexneri. PMID:24090466

Epidemiologic and clinical features of non-polio enteroviral infections in northern Taiwan in 2008.

PubMed

Hsu, Chien-Hui; Lu, Chun-Yi; Shao, Pei-Lan; Lee, Ping-Ing; Kao, Chuan-Liang; Chung, Ming-Yi; Chang, Luan-Yin; Huang, Li-Min

2011-08-01

Non-polio enteroviruses may cause different diseases, including herpangina, hand-foot-mouth disease (HFMD), meningitis, and nonspecific febrile illness; and cause epidemic outbreak annually. This study delineates the diversity of clinical presentations based on different serotypes and different groups [human enterovirus (HEV)-A and HEV-B] of enteroviruses (EVs) during the 2008 epidemic in National Taiwan University Hospital (NTUH). We retrospectively identified patients younger than 18 years who had positive isolates of non-polio EV in throat swabs, rectal swabs, or cerebrospinal fluid, in NTUH from January 1 to December 31, 2008. For serotyping, immunofluorescence assay and polymerase chain reaction followed by viral structure protein-1 sequencing were applied. We analyzed and compared their clinical features among different serotypes and different groups of EVs. Among 172 patients who were enrolled, 16 serotypes were identified. The major serotype in NTUH was EV71 (25.6%) followed by coxsackievirus A (CA)16 and coxsackievirus B (CB)4. EV71 manifested mostly as HFMD (89%) and was complicated with encephalomyelitis in three patients. Serotypes of HFMD included EV71 (70%), CA16 (27%), CA4, and CA6. Serotypes of herpangina were heterogeneous, and the major serotype was CA2 (35.7%) followed by CB4 (23.8%). Aseptic meningitis was entirely caused by HEV-B and mostly infected by echovirus 30 (50%). Among children with EV-related respiratory tract infection, CB4 (32%) was dominant in upper respiratory tract infection, whereas echovirus 4 (71%) was the major cause of lower respiratory tract infection. Cases of HEV-A were significantly younger than the cases of HEV-B (p = 0.04). Multivariate analysis revealed that the most significant factor associated with hospitalization is HEV-B (odds ratio, 2.2; 95% confidence interval, 1.1-4.2; p = 0.02). At least 16 serotypes circulated in northern Taiwan in 2008. EV71 is the predominant strain in this outbreak. All patients with HFMD were infected by HEV-A, but HEV-B was associated with a higher rate of hospitalization and aseptic meningitis, which should be a cause of alert regarding public health. Copyright © 2011. Published by Elsevier B.V.