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1

Reduction of potential respiratory pathogens by oral hygienic treatment in patients undergoing endotracheal anesthesia  

Microsoft Academic Search

Purpose.?This study was conducted to evaluate the usefulness of mechanical and chemical prophylactic oral cleansing treatments for\\u000a reducing potential respiratory pathogens existing in the oral cavity.\\u000a \\u000a \\u000a \\u000a \\u000a Methods.?Thirty-two patients scheduled to undergo oral and maxillofacial surgery that required endotracheal anesthesia were randomly\\u000a allocated to one of the two groups, the oral cleansing group (n = 16) or the noncleansing group (n

Minori Okuda; Yuzuru Kaneko; Tatsuya Ichinohe; Kazuyuki Ishihara; Katsuji Okuda

2003-01-01

2

Bighorn sheep (ovis canadensis) sinus tumors are associated with coinfections by potentially pathogenic bacteria in the upper respiratory tract.  

PubMed

Abstract Bighorn sheep (Ovis canadensis) sinus tumors are hyperplastic to neoplastic, predominantly stromal masses of the paranasal sinuses that expand the sinus lining and obstruct the sinus cavities. Obstruction of the sinus cavities and disruption of normal sinus lining anatomy may interfere with clearance of bacterial pathogens from the upper respiratory tract. To examine this possibility, we explored whether the presence of sinus tumor features (tumor score) affected the likelihood of detecting potentially pathogenic bacteria from upper respiratory sinus lining tissues in bighorn sheep. We developed or used existing PCR assays for the detection of leukotoxigenic Pasteurellaceae and Mycoplasma ovipneumoniae in sinus lining tissues collected from 97 bighorn sheep in Colorado, US from 2009 to 2012. With the use of logistic regression analyses we found that tumor score was a good predictor of the probability of detecting potentially pathogenic bacteria in sinus lining tissues; we were more likely to detect potentially pathogenic bacteria from samples with high tumor scores. These findings add to our understanding of possible mechanisms for the maintenance and shedding of bacterial agents from the upper respiratory tracts of bighorn sheep. PMID:25375938

Fox, Karen A; Rouse, Natalie M; Huyvaert, Kathryn P; Griffin, Karen A; Killion, Halcyon J; Jennings-Gaines, Jessica; Edwards, William H; Quackenbush, Sandra L; Miller, Michael W

2015-01-01

3

Multiplex detection of respiratory pathogens  

DOEpatents

Described are kits and methods useful for detection of respiratory pathogens (influenza A (including subtyping capability for H1, H3, H5 and H7 subtypes) influenza B, parainfluenza (type 2), respiratory syncytial virus, and adenovirus) in a sample. Genomic sequence information from the respiratory pathogens was analyzed to identify signature sequences, e.g., polynucleotide sequences useful for confirming the presence or absence of a pathogen in a sample. Primer and probe sets were designed and optimized for use in a PCR based, multiplexed Luminex assay to successfully identify the presence or absence of pathogens in a sample.

McBride, Mary (Brentwood, CA); Slezak, Thomas (Livermore, CA); Birch, James M. (Albany, CA)

2012-07-31

4

Genomic Sequencing Reveals Mutations Potentially Related to the Overattenuation of a Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus  

PubMed Central

Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) continues to evolve when serially passaged in Marc-145 cells. In this study, we analyzed the genomic and antigenic variants of HP-PRRSV strain JXA1 during in vitro passage. Protective efficacies of JXA1 from passages 100, 110, 120, 140, and 170 against the high-virulence parental virus were evaluated by inoculating pigs with each of these viruses and then challenging with JXA1 from passage 5 at 28 days postimmunization. We found that the antigenicities of JXA1 from passages after 110 were significantly reduced. Inoculation with JXA1 from passages after 110 provided only insufficient protection against the parental strain challenge, indicating that the immunogenicity of JXA1 is significantly decreased when it is in vitro passaged for 110 times and more. To identify the genomic variants that emerged during the overattenuation, eight complete genomes of highly passaged JXA1 were sequenced. One guanine deletion in the 5? untranslated region (UTR), two nucleotide substitutions in the 3? UTR, and 65 amino acid mutations in nonstructural and structural proteins that accompanied with the attenuation and overattenuation were determined. Genomic sequencing of in vitro serially passaged HP-PRRSV first identified the mutations potentially correlated with the overattenuation of a HP-PRRSV strain. These results facilitate the research aimed at elucidating the mechanisms for PRRSV genomic and antigenic changes and may also contribute to developing a safe and effective PRRSV vaccine. PMID:23408525

Yu, Xiuling; Chen, Nanhua; Deng, Xiaoyu; Cao, Zhen; Han, Wei; Hu, Dongmei; Wu, Jiajun; Zhang, Shuo; Wang, Baoyue; Gu, Xiaoxue

2013-01-01

5

Pathogen Chip for Respiratory Tract Infections  

PubMed Central

Determining the viral etiology of respiratory tract infections (RTI) has been limited for the most part to specific primer PCR-based methods due to their increased sensitivity and specificity compared to other methods, such as tissue culture. However, specific primer approaches have limited the ability to fully understand the diversity of infecting pathogens. A pathogen chip system (PathChip), developed at the Genome Institute of Singapore (GIS), using a random-tagged PCR coupled to a chip with over 170,000 probes, has the potential to recognize all known human viral pathogens. We tested 290 nasal wash specimens from Filipino children <2 years of age with respiratory tract infections using culture and 3 PCR methods—EraGen, Luminex, and the GIS PathChip. The PathChip had good diagnostic accuracy, ranging from 85.9% (95% confidence interval [CI], 81.3 to 89.7%) for rhinovirus/enteroviruses to 98.6% (95% CI, 96.5 to 99.6%) for PIV 2, compared to the other methods and additionally identified a number of viruses not detected by these methods. PMID:23303493

Patel, Champa; Sung, Wing-Kin; Lee, Charlie W. H.; Loh, Kuan Hon; Lucero, Marilla; Nohynek, Hanna; Nai, Geraldine; Thien, Pei Ling; Koh, Chee Wee; Chan, Yang Sun; Ma, Jianmin; Maurer-Stroh, Sebastian; Carosone-Link, Phyllis; Hibberd, Martin L.; Wong, Christopher W.

2013-01-01

6

Potentiation effects of amikacin and fosfomycin against selected amikacin-nonsusceptible Gram-negative respiratory tract pathogens.  

PubMed

The amikacin-fosfomycin inhalation system (AFIS) is a combination of 2 antibiotics and an in-line nebulizer delivery system that is being developed for adjunctive treatment of pneumonia caused by Gram-negative organisms in patients on mechanical ventilation. AFIS consists of a combination of amikacin and fosfomycin solutions at a 5:2 ratio (amikacin, 3 ml at 100 mg/ml; fosfomycin, 3 ml at 40 mg/ml) and the PARI Investigational eFlow Inline System. In this antibiotic potentiation study, the antimicrobial activities of amikacin and fosfomycin, alone and in a 5:2 combination, were assessed against 62 Gram-negative pathogens from a worldwide antimicrobial surveillance collection (SENTRY). The amikacin MICs for 62 isolates of Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae were ?32 ?g/ml (intermediate or resistant according to the Clinical and Laboratory Standards Institute [CLSI]; resistant according to the European Committee on Antimicrobial Susceptibility Testing [EUCAST]). Each isolate was tested against amikacin (0.25 to 1,024 ?g/ml), fosfomycin (0.1 to 409.6 ?g/ml), and amikacin-fosfomycin (at a 5:2 ratio) using CLSI reference agar dilution methods. The median MIC values for amikacin and fosfomycin against the 62 isolates each decreased 2-fold with the amikacin-fosfomycin (5:2) combination from that with either antibiotic alone. Interactions between amikacin and fosfomycin differed by isolate and ranged from no detectable interaction to high potentiation. The amikacin-fosfomycin (5:2) combination reduced the amikacin concentration required to inhibit all 62 isolates from >1,024 to ? 256 ?g/ml and reduced the required fosfomycin concentration from 204.8 to 102.4 ?g/ml. These results support continued development of the amikacin-fosfomycin combination for aerosolized administration, where high drug levels can be achieved. PMID:24752275

Montgomery, A Bruce; Rhomberg, Paul R; Abuan, Tammy; Walters, Kathie-Anne; Flamm, Robert K

2014-07-01

7

Potentiation Effects of Amikacin and Fosfomycin against Selected Amikacin-Nonsusceptible Gram-Negative Respiratory Tract Pathogens  

PubMed Central

The amikacin-fosfomycin inhalation system (AFIS) is a combination of 2 antibiotics and an in-line nebulizer delivery system that is being developed for adjunctive treatment of pneumonia caused by Gram-negative organisms in patients on mechanical ventilation. AFIS consists of a combination of amikacin and fosfomycin solutions at a 5:2 ratio (amikacin, 3 ml at 100 mg/ml; fosfomycin, 3 ml at 40 mg/ml) and the PARI Investigational eFlow Inline System. In this antibiotic potentiation study, the antimicrobial activities of amikacin and fosfomycin, alone and in a 5:2 combination, were assessed against 62 Gram-negative pathogens from a worldwide antimicrobial surveillance collection (SENTRY). The amikacin MICs for 62 isolates of Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae were ?32 ?g/ml (intermediate or resistant according to the Clinical and Laboratory Standards Institute [CLSI]; resistant according to the European Committee on Antimicrobial Susceptibility Testing [EUCAST]). Each isolate was tested against amikacin (0.25 to 1,024 ?g/ml), fosfomycin (0.1 to 409.6 ?g/ml), and amikacin-fosfomycin (at a 5:2 ratio) using CLSI reference agar dilution methods. The median MIC values for amikacin and fosfomycin against the 62 isolates each decreased 2-fold with the amikacin-fosfomycin (5:2) combination from that with either antibiotic alone. Interactions between amikacin and fosfomycin differed by isolate and ranged from no detectable interaction to high potentiation. The amikacin-fosfomycin (5:2) combination reduced the amikacin concentration required to inhibit all 62 isolates from >1,024 to ?256 ?g/ml and reduced the required fosfomycin concentration from 204.8 to 102.4 ?g/ml. These results support continued development of the amikacin-fosfomycin combination for aerosolized administration, where high drug levels can be achieved. PMID:24752275

Rhomberg, Paul R.; Abuan, Tammy; Walters, Kathie-Anne; Flamm, Robert K.

2014-01-01

8

Crystal Structures of Respiratory Pathogen Neuraminidases  

SciTech Connect

Currently there is pressing need to develop novel therapeutic agents for the treatment of infections by the human respiratory pathogens Pseudomonas aeruginosa and Streptococcus pneumoniae. The neuraminidases of these pathogens are important for host colonization in animal models of infection and are attractive targets for drug discovery. To aid in the development of inhibitors against these neuraminidases, we have determined the crystal structures of the P. aeruginosa enzyme NanPs and S. pneumoniae enzyme NanA at 1.6 and 1.7 {angstrom} resolution, respectively. In situ proteolysis with trypsin was essential for the crystallization of our recombinant NanA. The active site regions of the two enzymes are strikingly different. NanA contains a deep pocket that is similar to that in canonical neuraminidases, while the NanPs active site is much more open. The comparative studies suggest that NanPs may not be a classical neuraminidase, and may have distinct natural substrates and physiological functions. This work represents an important step in the development of drugs to prevent respiratory tract colonization by these two pathogens.

Hsiao, Y.; Parker, D; Ratner, A; Prince, A; Tong, L

2009-01-01

9

Tools for Detection of Mycoplasma amphoriforme: a Primary Respiratory Pathogen?  

PubMed Central

Mycoplasma amphoriforme is a recently described organism isolated from the respiratory tracts of patients with immunodeficiency and evidence of chronic infection. Novel assays for the molecular detection of the organism by real-time quantitative PCRs (qPCRs) targeting the uracil DNA glycosylase gene (udg) or the 23S rRNA gene are described here. The analytical sensitivities are similar to the existing conventional M. amphoriforme 16S rRNA gene PCR, with the advantage of being species specific, rapid, and quantitative. By using these techniques, we demonstrate the presence of this organism in 17 (19.3%) primary antibody-deficient (PAD) patients, 4 (5%) adults with lower respiratory tract infection, 1 (2.6%) sputum sample from a patient attending a chest clinic, and 23 (0.21%) samples submitted for viral diagnosis of respiratory infection, but not in normal adult control subjects. These data show the presence of this microorganism in respiratory patients and suggest that M. amphoriforme may infect both immunocompetent and immunocompromised people. Further studies to characterize this organism are required, and this report provides the tools that may be used by other research groups to investigate its pathogenic potential. PMID:24478412

Ling, Clare L.; Oravcova, Katarina; Beattie, Thomas F.; Creer, Dean D.; Dilworth, Paul; Fulton, Naomi L.; Hardie, Alison; Munro, Michelle; Pond, Marcus; Templeton, Kate; Webster, David; Workman, Sarita; McHugh, Timothy D.

2014-01-01

10

Human bocavirus, a real respiratory tract pathogen  

Microsoft Academic Search

A new virus was discovered by molecular techniques in respiratory samples collected from young children with respiratory diseases in Sweden in 2005. The virus, named human bocavirus, is genetically related to the bovine parvovirus and the canine minute virus, both of which belong to the bocavirus genus of the parvoviridae family. Recent studies conducted in different countries have shown that

Zhenqiang Bi; Pierre B. H. Formenty; Cathy E. Roth

2007-01-01

11

Contribution of respiratory pathogens to influenza-like illness consultations.  

PubMed

Influenza-like illnesses (ILIs) are caused by several respiratory pathogens. These pathogens show weak to strong seasonal activity implying seasonality in ILI consultations. In this paper, the contribution of pathogens to seasonality of ILI consultations was statistically modelled. Virological count data were first smoothed using modulation models for seasonal time series. Second, Poisson regression was used regressing ILI consultation counts on the smoothed time series. Using ratios of the estimated regression parameters, relative measures of the underreporting of pathogens were obtained. Influenza viruses A and B, parainfluenza virus and respiratory syncytial virus (RSV) significantly contributed to explain the seasonal variation in ILI consultations. We also found that RSV was the least and influenza virus A is the most underreported pathogen in Belgian laboratory surveillance. The proposed methods and results are helpful in interpreting the data of clinical and laboratory surveillance, which are the essential parts of influenza surveillance. PMID:23217849

Bollaerts, K; Antoine, J; Van Casteren, V; Ducoffre, G; Hens, N; Quoilin, S

2013-10-01

12

Corynebacterium pseudodiphtheriticum: a respiratory tract pathogen.  

PubMed

From January 1986 through February 1993, there were 16 episodes of respiratory infection due to Corynebacterium pseudodiphtheriticum in 13 patients. The ages of patients ranged from 24 to 77 years; the ratio of male to female patients was 3:1. One patient had three episodes of infection, and another patient had two. In one patient, who died of disseminated intravascular coagulation, the level of IgG was low. One patient was receiving prednisolone when the infection occurred. In two cases a mixed infection with Streptococcus pneumoniae was noted. Sputum cultures yielded C. pseudodiphtheriticum (> or = 10(7) cfu/mL). An increased neutrophil response in the sputum of infected patients was observed. Gram staining and electron microscopy of sputum showed phagocytosis of C. pseudodiphtheriticum by the neutrophils. ELISAs also showed an increase in the level of immunoglobulin against C. pseudodiphtheriticum after infection. Tests for determination of MICs of antibiotics revealed that C. pseudodiphtheriticum isolates were susceptible to ampicillin, amoxycillin/clavulanic acid, cefazolin, cefuroxime, ceftazidime, and imipenem. All strains were resistant to nalidixic acid; borderline susceptibility to ofloxacin, norfloxacin, and ciprofloxacin was noted. We suggest the use of beta-lactam antibiotics in the treatment of infection with C. pseudodiphtheriticum. PMID:7727668

Ahmed, K; Kawakami, K; Watanabe, K; Mitsushima, H; Nagatake, T; Matsumoto, K

1995-01-01

13

High seroprevalence of respiratory pathogens in hobby poultry.  

PubMed

Seroprevalence studies on respiratory pathogens have been done extensively in commercial laying hens, broilers, and, to a lesser extent, backyard poultry. In Europe, seroprevalence studies in backyard and fancy breed poultry flocks are scarce and limited to a few pathogens, such as Mycoplasma gallisepticum (MG); others, such as Ornithobacterium rhinotracheale (ORT), are missing. A commercial ELISA for detection of antibodies against six selected pathogens was performed on 460 serum samples from chickens across Flanders. Anti-ORT antibodies were, by far, the most prevalent, with a prevalence of 95.4%. Infectious bronchitis virus, Mycoplasma synoviae, and avian metapneumovirus antibodies were found in 75.6%, 76.3%, and 63.5% of the animals, respectively. Antibodies against MG and infectious laryngotracheitis virus were found in 36.7% and 30% of the animals, respectively. These data demonstrate the high seroprevalence of respiratory pathogens among hobby poultry; therefore, it is possible that this group could act as a reservoir for commercially kept poultry. PMID:25619008

Haesendonck, R; Verlinden, M; Devos, G; Michiels, T; Butaye, P; Haesebrouck, F; Pasmans, F; Martel, A

2014-12-01

14

Corynebacterium pseudodiphtheriticum: a respiratory tract pathogen in adults.  

PubMed

Corynebacterium pseudodiphtheriticum has been reported to be an uncommon respiratory pathogen. We describe the clinical and microbiologic features of 17 patients from whose sputum C. pseudodiphtheriticum was isolated. Patients were identified through a review of the reports from the clinical microbiology laboratory at York Hospital, a community teaching hospital, from October 1990 through April 1993; 17 patients with respiratory infection caused by C. pseudodiphthriticum were identified. There were 12 cases of bronchitis and five of pneumonia. An underlying systemic condition, particularly congestive heart failure, chronic obstructive pulmonary disease, diabetes mellitus, or malignancy, was common. Onset of symptomatology was acute for most patients, but fever was noticeably absent in almost two-thirds of the cases. Isolates were uniformly susceptible to the beta-lactam antibiotics, vancomycin, and trimethoprim-sulfamethoxazole, but resistance to clindamycin and erythromycin was common. The isolation of diphtheroids from a properly obtained sputum sample from a patient with respiratory tract infection should not always be dismissed as due to contamination. The isolation, identification, and susceptibility testing of C. pseudodiphtheriticum from respiratory tract specimens may provide information useful for treatment of patients. PMID:7727667

Manzella, J P; Kellogg, J A; Parsey, K S

1995-01-01

15

Detection of respiratory pathogens in aerosols from acutely infected pigs  

Technology Transfer Automated Retrieval System (TEKTRAN)

Infectious agents that cause respiratory disease in pigs include porcine reproductive respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), swine influenza virus (SIV), porcine respiratory corona virus (PRCV), Mycoplasma hyopneumoniae, and Bordetella bronchiseptica. The objective of...

16

Corynebacterium pseudodiphtheriticum: an easily missed respiratory pathogen in HIV-infected patients.  

PubMed

Despite being a well-known respiratory pathogen for immunocompromised patients, Corynebacterium pseudodiphtheriticum has uncommonly been reported to occur in persons with infection attributable to HIV virus. We report three cases of respiratory tract infection attributable to C. pseudodiphtheriticum in HIV-infected patients and review the four previous cases from the medical literature. All of them were male with a median CD4 lymphocyte count of 110 cells/mm3 (range, 18-198/mm3); five of the seven cases occurred in persons for whom AIDS was diagnosed previously. The onset of symptomatology was usually acute and the most common radiographic appearance was alveolar infiltrate (six patients) with cavitation (two patients) and pleural effusion (two patients). In five of the seven cases, C. pseudodiphtheriticum was isolated from bronchoscopic samples and in the remaining two cases was recovered from lung biopsy (one patient) and sputum (one patient). In the three patients reported herein and in one previous case from the medical literature, quantitative culturing of bronchoscopic samples obtained through either bronchoalveolar lavage or protected brush catheter procedures yielded more than 10(3) CFU/mL. All the strains tested were susceptible to penicillin and vancomycin. Resistance to macrolides was common. Recovery was observed in six of the seven patients. C. pseudodiphtheriticum should be regarded as a potential respiratory pathogen in HIV-infected patients. This infection presents late in the course of HIV disease and it seems to respond well to appropriate antibiotic treatment in most of the cases. This easily overlooked pathogen should be added to the list of organisms implicated in respiratory tract infections in this population. PMID:10212746

Gutiérrez-Rodero, F; Ortiz de la Tabla, V; Martínez, C; Masiá, M M; Mora, A; Escolano, C; González, E; Martin-Hidalgo, A

1999-04-01

17

Host Response to Respiratory Bacterial Pathogens as Identified by Integrated Analysis of Human Gene Expression Data  

PubMed Central

Respiratory bacterial pathogens are one of the leading causes of infectious death in the world and a major health concern complicated by the rise of multi-antibiotic resistant strains. Therapeutics that modulate host genes essential for pathogen infectivity could potentially avoid multi-drug resistance and provide a wider scope of treatment options. Here, we perform an integrative analysis of published human gene expression data generated under challenges from the gram-negative and Gram-positive bacteria pathogens, Pseudomonas aeruginosa and Streptococcus pneumoniae, respectively. We applied a previously described differential gene and pathway enrichment analysis pipeline to publicly available host mRNA GEO datasets resulting from exposure to bacterial infection. We found 72 canonical human pathways common between four GEO datasets, representing P. aeruginosa and S. pneumoniae. Although the majority of these pathways are known to be involved with immune response, we found several interesting new interactions such as the SUMO1 pathway that might have a role in bacterial infections. Furthermore, 36 host-bacterial pathways were also shared with our previous results for respiratory virus host gene expression. Based on our pathway analysis we propose several drug-repurposing opportunities supported by the literature. PMID:24086587

Smith, Steven B.; Magid-Slav, Michal; Brown, James R.

2013-01-01

18

Potential impact of fireworks on respiratory health  

PubMed Central

The world-wide use of fireworks with their consequent detrimental effect on the air quality is widely recognized with elevated ambient air levels of particulate matter and its several metallic components and gases identified in several studies carried out during such events. Exposed individuals may be at risk following inhalation of such produced pollutants. This review focuses on the impact of fireworks on air quality and the potential effect of fireworks on the respiratory system of healthy individuals as well as those suffering from underlying respiratory diseases, particularly asthma and chronic obstructive pulmonary disease (COPD). This applies not only to spectators including children but also to pyrotechnicians themselves. An extensive Medline search revealed that a strong evidence of the impact of fireworks on respiratory health is lacking in susceptible as well as healthy individuals with no formal studies on COPD or asthma, other than a few case reports in the latter. The implementation of global strategies to control the use of fireworks and hence improve air quality could possibly reduce their likely detrimental effect on human respiratory health in exposed individuals, but clearly a more targeted research is needed. PMID:25378846

Gouder, Caroline; Montefort, Stephen

2014-01-01

19

Potential impact of fireworks on respiratory health.  

PubMed

The world-wide use of fireworks with their consequent detrimental effect on the air quality is widely recognized with elevated ambient air levels of particulate matter and its several metallic components and gases identified in several studies carried out during such events. Exposed individuals may be at risk following inhalation of such produced pollutants. This review focuses on the impact of fireworks on air quality and the potential effect of fireworks on the respiratory system of healthy individuals as well as those suffering from underlying respiratory diseases, particularly asthma and chronic obstructive pulmonary disease (COPD). This applies not only to spectators including children but also to pyrotechnicians themselves. An extensive Medline search revealed that a strong evidence of the impact of fireworks on respiratory health is lacking in susceptible as well as healthy individuals with no formal studies on COPD or asthma, other than a few case reports in the latter. The implementation of global strategies to control the use of fireworks and hence improve air quality could possibly reduce their likely detrimental effect on human respiratory health in exposed individuals, but clearly a more targeted research is needed. PMID:25378846

Gouder, Caroline; Montefort, Stephen

2014-10-01

20

Comparison of four multiplex PCR assays for the detection of viral pathogens in respiratory specimens.  

PubMed

Multiplex PCR has become the test of choice for the detection of multiple respiratory viruses in clinical specimens. However, there are few direct comparisons of different PCR assays. This study compares 4 different multiplex PCR assays for the recovery of common respiratory viruses. We tested 213 respiratory specimens using four different multiplex PCR assays: the xTAG respiratory viral panel fast (Abbott Molecular Laboratories), Fast-track Respiratory Pathogen assay (Fast-track Diagnostics), Easyplex respiratory pathogen 12 kit (Ausdiagnostics), and an in-house multiplex real-time PCR assay. The performance of the four assays was very similar, with 93-100% agreement for all comparisons. Other issues, such as through-put, technical requirements and cost, are likely to be as important for making a decision about which of these assays to use given their comparative performance. PMID:23583489

Anderson, Trevor P; Werno, Anja M; Barratt, Kevin; Mahagamasekera, Patalee; Murdoch, David R; Jennings, Lance C

2013-08-01

21

Detection of pathogens in Boidae and Pythonidae with and without respiratory disease.  

PubMed

Respiratory diseases in boid snakes are common in captivity, but little information is available on their aetiology. This study was carried out to determine the occurrence of lung associated pathogens in boid snakes with and without respiratory signs and/or pneumonia. In total, 80 boid snakes of the families Boidae (n = 30) and Pythonidae (n = 50) from 48 private and zoo collections were included in this survey. Husbandry conditions were evaluated using a detailed questionnaire. All snakes were examined clinically and grouped into snakes with or without respiratory signs. Tracheal wash samples from all snakes were examined bacteriologically as well as virologically. All snakes were euthanased, and a complete pathological examination was performed. Respiratory signs and pneumonia were detected more often in pythons than in boas. An acute catarrhal pneumonia was diagnosed more often in snakes without respiratory signs than in snakes with respiratory signs, which revealed fibrinous and fibrous pneumonia. Poor husbandry conditions are an important trigger for the development of respiratory signs and pneumonia. Different bacterial pathogens were isolated in almost all snakes with pneumonia, with Salmonella species being the most common. Ferlavirus (formerly known as ophidian paramyxovirus)-RNA was detected only in pythons. Inclusion body disease was rarely seen in pythons but often in boas. Adenovirus and Mycoplasma were other pathogens that were diagnosed in single snakes with pneumonia. In living boid snakes with respiratory signs, tracheal wash samples were found to be a useful diagnostic tool for the detection of viral and bacterial pathogens. PMID:23322542

Schmidt, V; Marschang, R E; Abbas, M D; Ball, I; Szabo, I; Helmuth, R; Plenz, B; Spergser, J; Pees, M

2013-03-01

22

Is There Still Room for Novel Viral Pathogens in Pediatric Respiratory Tract Infections?  

PubMed Central

Viruses are the most frequent cause of respiratory disease in children. However, despite the advanced diagnostic methods currently in use, in 20 to 50% of respiratory samples a specific pathogen cannot be detected. In this work, we used a metagenomic approach and deep sequencing to examine respiratory samples from children with lower and upper respiratory tract infections that had been previously found negative for 6 bacteria and 15 respiratory viruses by PCR. Nasal washings from 25 children (out of 250) hospitalized with a diagnosis of pneumonia and nasopharyngeal swabs from 46 outpatient children (out of 526) were studied. DNA reads for at least one virus commonly associated to respiratory infections was found in 20 of 25 hospitalized patients, while reads for pathogenic respiratory bacteria were detected in the remaining 5 children. For outpatients, all the samples were pooled into 25 DNA libraries for sequencing. In this case, in 22 of the 25 sequenced libraries at least one respiratory virus was identified, while in all other, but one, pathogenic bacteria were detected. In both patient groups reads for respiratory syncytial virus, coronavirus-OC43, and rhinovirus were identified. In addition, viruses less frequently associated to respiratory infections were also found. Saffold virus was detected in outpatient but not in hospitalized children. Anellovirus, rotavirus, and astrovirus, as well as several animal and plant viruses were detected in both groups. No novel viruses were identified. Adding up the deep sequencing results to the PCR data, 79.2% of 250 hospitalized and 76.6% of 526 ambulatory patients were positive for viruses, and all other children, but one, had pathogenic respiratory bacteria identified. These results suggest that at least in the type of populations studied and with the sampling methods used the odds of finding novel, clinically relevant viruses, in pediatric respiratory infections are low. PMID:25412469

Taboada, Blanca; Espinoza, Marco A.; Isa, Pavel; Aponte, Fernando E.; Arias-Ortiz, María A.; Monge-Martínez, Jesús; Rodríguez-Vázquez, Rubén; Díaz-Hernández, Fidel; Zárate-Vidal, Fernando; Wong-Chew, Rosa María; Firo-Reyes, Verónica; del Río-Almendárez, Carlos N.; Gaitán-Meza, Jesús; Villaseñor-Sierra, Alberto; Martínez-Aguilar, Gerardo; Salas-Mier, Ma. del Carmen; Noyola, Daniel E.; Pérez-Gónzalez, Luis F.; López, Susana; Santos-Preciado, José I.; Arias, Carlos F.

2014-01-01

23

Evaluation of the Pathogenicity of a Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Variant in Piglets  

Microsoft Academic Search

Since May 2006, a highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) variant characterized by 30 amino acids deletion within its NSP2-coding region emerged and caused extensive economic losses to China's pig industry. To investigate the in vivo pathogenicity and immune responses of the newly emerging PRRSV, 3 groups of 60-d-old conventional piglets were inoculated intranasally with a representative

Tian-chao WEI; Zhi-jun TIAN; Yan-jun ZHOU; Tong-qing AN; Yi-feng JIANG; Yan XIAO; Shouping HU; Jin-mei PENG; Xiao-fang HAO; Shan-rui ZHANG; Guang-zhi TONG

2011-01-01

24

Implementing hospital-based surveillance for severe acute respiratory infections caused by influenza and other respiratory pathogens in New Zealand  

PubMed Central

Background Recent experience with pandemic influenza A(H1N1)pdm09 highlighted the importance of global surveillance for severe respiratory disease to support pandemic preparedness and seasonal influenza control. Improved surveillance in the southern hemisphere is needed to provide critical data on influenza epidemiology, disease burden, circulating strains and effectiveness of influenza prevention and control measures. Hospital-based surveillance for severe acute respiratory infection (SARI) cases was established in New Zealand on 30 April 2012. The aims were to measure incidence, prevalence, risk factors, clinical spectrum and outcomes for SARI and associated influenza and other respiratory pathogen cases as well as to understand influenza contribution to patients not meeting SARI case definition. Methods/Design All inpatients with suspected respiratory infections who were admitted overnight to the study hospitals were screened daily. If a patient met the World Health Organization’s SARI case definition, a respiratory specimen was tested for influenza and other respiratory pathogens. A case report form captured demographics, history of presenting illness, co-morbidities, disease course and outcome and risk factors. These data were supplemented from electronic clinical records and other linked data sources. Discussion Hospital-based SARI surveillance has been implemented and is fully functioning in New Zealand. Active, prospective, continuous, hospital-based SARI surveillance is useful in supporting pandemic preparedness for emerging influenza A(H7N9) virus infections and seasonal influenza prevention and control. PMID:25077034

Baker, Michael; McArthur, Colin; Roberts, Sally; Williamson, Deborah; Grant, Cameron; Trenholme, Adrian; Wong, Conroy; Taylor, Susan; LeComte, Lyndsay; Mackereth, Graham; Bandaranayake, Don; Wood, Tim; Bissielo, Ange; Se, Ruth; Turner, Nikki; Pierse, Nevil; Thomas, Paul; Webby, Richard; Gross, Diane; Duque, Jazmin; Thompson, Mark; Widdowson, Marc-Alain

2014-01-01

25

Non-diphtheriae Corynebacterium species: an emerging respiratory pathogen.  

PubMed

The purpose of the study was to describe the microbiological and clinical features of ten cases of lower respiratory tract infection due to Corynebacterium striatum, Corynebacterium propinquum and Corynebacterium pseudodiphtheriticum. Respiratory samples were recovered from hospitalised patients who were diagnosed of pneumonia and exacerbations of chronic respiratory infections. The samples were Gram-stained and seeded on conventional bacterial growing media. Bacteria were identified by matrix-assisted linear desorption/ionisation-time-of-flight mass spectrometry (MALDI-TOF MS). Antibiotic susceptibility was tested by the disk diffusion method. All patients presented an acute respiratory onset, most of them in the context of an underlying disease and/or immunosuppression. In all patients, the microscopical examination of Gram-stained respiratory samples showed numerous polymorphonuclear cells and Gram-positive bacilli, suggestive of the Corynebacterium morphotype. A pure culture growth of Corynebacterium was obtained in the majority (72 %) of samples. The conclusions are that non-diphtheriae Corynebacterium species are an emerging cause of respiratory infection among patients with chronic respiratory disease and/or immunosuppression, and cannot always be considered as mere colonisers. The microorganism's predominance in Gram-stained purulent respiratory samples together with abundant growth in the culture is the key for the microbiological diagnosis. PMID:23271676

Díez-Aguilar, M; Ruiz-Garbajosa, P; Fernández-Olmos, A; Guisado, P; Del Campo, R; Quereda, C; Cantón, R; Meseguer, M A

2013-06-01

26

Epidemiology of Pathogen-Specific Respiratory Infections among Three US Populations  

PubMed Central

Background Diagnostic tests for respiratory infections can be costly and time-consuming. Improved characterization of specific respiratory pathogens by identifying frequent signs, symptoms and demographic characteristics, along with improving our understanding of coinfection rates and seasonality, may improve treatment and prevention measures. Methods Febrile respiratory illness (FRI) and severe acute respiratory infection (SARI) surveillance was conducted from October 2011 through March 2013 among three US populations: civilians near the US–Mexico border, Department of Defense (DoD) beneficiaries, and military recruits. Clinical and demographic questionnaire data and respiratory swabs were collected from participants, tested by PCR for nine different respiratory pathogens and summarized. Age stratified characteristics of civilians positive for influenza and recruits positive for rhinovirus were compared to other and no/unknown pathogen. Seasonality and coinfection rates were also described. Results A total of 1444 patients met the FRI or SARI case definition and were enrolled in this study. Influenza signs and symptoms varied across age groups of civilians. Recruits with rhinovirus had higher percentages of pneumonia, cough, shortness of breath, congestion, cough, less fever and longer time to seeking care and were more likely to be male compared to those in the no/unknown pathogen group. Coinfections were found in 6% of all FRI/SARI cases tested and were most frequently seen among children and with rhinovirus infections. Clear seasonal trends were identified for influenza, rhinovirus, and respiratory syncytial virus. Conclusions The age-stratified clinical characteristics associated with influenza suggest that age-specific case definitions may improve influenza surveillance and identification. Improving identification of rhinoviruses, the most frequent respiratory infection among recruits, may be useful for separating out contagious individuals, especially when larger outbreaks occur. Overall, describing the epidemiology of pathogen specific respiratory diseases can help improve clinical diagnoses, establish baselines of infection, identify outbreaks, and help prioritize the development of new vaccines and treatments. PMID:25549089

Radin, Jennifer M.; Hawksworth, Anthony W.; Kammerer, Peter E.; Balansay, Melinda; Raman, Rema; Lindsay, Suzanne P.; Brice, Gary T.

2014-01-01

27

Corynebacterium pseudodiphtheriticum: an easily missed respiratory pathogen in HIV-infected patients  

Microsoft Academic Search

Despite being a well-known respiratory pathogen for immunocompromised patients, Corynebacterium pseudodiphtheriticum has uncommonly been reported to occur in persons with infection attributable to HIV virus. We report three cases of respiratory tract infection attributable to C. pseudodiphtheriticum in HIV-infected patients and review the four previous cases from the medical literature. All of them were male with a median CD4 lymphocyte

Félix Gutiérrez-Rodero; Victoria Ortiz de la Tabla; Carmen Mart??nez; Mar??a del Mar Masiá; Antonia Mora; Clara Escolano; Eva González; Alberto Martin-Hidalgo

1999-01-01

28

Human metapneumovirus: review of an important respiratory pathogen.  

PubMed

Human metapneumovirus (hMPV), discovered in 2001, most commonly causes upper and lower respiratory tract infections in young children, but is also a concern for elderly subjects and immune-compromised patients. hMPV is the major etiological agent responsible for about 5% to 10% of hospitalizations of children suffering from acute respiratory tract infections. hMPV infection can cause severe bronchiolitis and pneumonia in children, and its symptoms are indistinguishable from those caused by human respiratory syncytial virus. Initial infection with hMPV usually occurs during early childhood, but re-infections are common throughout life. Due to the slow growth of the virus in cell culture, molecular methods (such as reverse transcriptase PCR (RT-PCR)) are the preferred diagnostic modality for detecting hMPV. A few vaccine candidates have been shown to be effective in preventing clinical disease, but none are yet commercially available. Our understanding of hMPV has undergone major changes in recent years and in this article we will review the currently available information on the molecular biology and epidemiology of hMPV. We will also review the current therapeutic interventions and strategies being used to control hMPV infection, with an emphasis on possible approaches that could be used to develop an effective vaccine against hMPV. PMID:24841931

Panda, Swagatika; Mohakud, Nirmal Kumar; Pena, Lindomar; Kumar, Subrat

2014-08-01

29

Detection of respiratory tract pathogens with molecular biology methods.  

PubMed

This paper describes the use in routine diagnosis of virological kit, which was designed to identify the 15 most common respiratory viruses in clinical specimens of nasopharyngeal aspirates, swabs, and bronchoalveolar lavage. It is a one-step multiplex RT-PCR system for the detection of influenza virus type A and type B, human respiratory syncytial virus type A, B; human adenovirus, human metapneumovirus, human coronaviruses 229E/NL63 and OC43, human parainfluenza type 1, 2, 3, human rhinovirus type A, B, human enterovirus, and bocavirus 1, 2, 3, 4. The article presents research conducted on the basis of swabs collected from patients who came to the Ear, Nose, and Throat Emergency Care Unit at the Department of Otolaryngology, Military Medical Institute in Warsaw, in February 2013. Due to the nature of work in an laryngological emergency ward, the material was collected only from those patients who reported problems associated with rhinitis or any dysfunction of the upper respiratory tract. The study shows that patients who came to seek laryngological assistance were usually infected with viruses having affinity for the airway epithelium. PMID:25252894

Wozniak-Kosek, A; Kosek, J; Zielnik-Jurkiewicz, B

2015-01-01

30

Reverse Transcription-PCR–Electrospray Ionization Mass Spectrometry for Rapid Detection of Biothreat and Common Respiratory Pathogens  

PubMed Central

Electrospray ionization mass spectrometry (ESI-MS) analysis of reverse transcription (RT)-PCR amplicons from human respiratory samples allows for broad pathogen identification approximately 8 h after collection. We investigated the performance characteristics of a high-throughput RT-PCR-coupled ESI-MS assay for distinguishing biothreat (BT) agents from common bacterial, fungal, and viral respiratory pathogens in bronchoalveolar lavage (BAL) fluid specimens from subjects with suspected respiratory infections. In a retrospective case series, 202 BAL fluid specimens were collected at the Johns Hopkins Hospital between August 2010 and February 2011 from patients with suspected acute respiratory infections. Samples were processed using standard bacterial, viral, and fungal testing in the clinical microbiology laboratory as part of routine care and then were blindly spiked with either water or nucleic acids from BT organisms (Bacillus anthracis, Yersinia pestis, Francisella tularensis, Brucella spp., Burkholderia spp., and Rickettsia prowazekii) and tested by RT-PCR–ESI-MS. The sensitivities and specificities of RT-PCR–ESI-MS versus standard clinical methods were as follows: for mock BT DNA, 98.5% sensitivity (95% confidence interval [CI], 94.2 to 99.7%) and 100% specificity (95% CI, 93.1 to 100.0%); for bacterial pathogens, 81.8% sensitivity (95% CI, 74.3 to 87.6%) and 73.6% specificity (95% CI, 64.2 to 81.4%); for viral pathogens, 93.3% sensitivity (95% CI, 66.0 to 99.7%) and 97.3% specificity (95% CI, 89.7 to 99.5%); for fungal pathogens, 42.6% sensitivity (95% CI, 29.5 to 56.7%) and 97.8% specificity (95% CI, 91.8 to 99.6%). Our data suggest that RT-PCR–ESI-MS is a useful adjunct to standard culture protocols for rapid detection of both BT and common respiratory pathogens; further study is required for assay validation, especially for fungal detection, and potential implementation. PMID:23903543

Jeng, Kevin; Rothman, Richard; Yang, Samuel; Won, Helen; Peterson, Stephen; Hsieh, Yu-Hsiang; Masek, Billie Jo; Carroll, Karen C.; Gaydos, Charlotte A.

2013-01-01

31

Complete genome sequence of a novel highly pathogenic porcine reproductive and respiratory syndrome virus variant.  

PubMed

Highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRS) emerged in China in 2006, and HP-PRRS virus (HP-PRRSV) has evolved continuously. Here, the complete genomic sequence of a novel HP-PRRSV field strain, JX, is reported. The present finding will contribute to further studies focusing on the evolutionary mechanism of PRRSV. PMID:23118452

Wang, Lianghai; Hou, Jun; Zhang, Hexiao; Feng, Wen-hai

2012-12-01

32

Transcriptome profile of a bovine respiratory disease pathogen: Mannheimia haemolytica PHL213  

PubMed Central

Background Computational methods for structural gene annotation have propelled gene discovery but face certain drawbacks with regards to prokaryotic genome annotation. Identification of transcriptional start sites, demarcating overlapping gene boundaries, and identifying regulatory elements such as small RNA are not accurate using these approaches. In this study, we re-visit the structural annotation of Mannheimia haemolytica PHL213, a bovine respiratory disease pathogen. M. haemolytica is one of the causative agents of bovine respiratory disease that results in about $3 billion annual losses to the cattle industry. We used RNA-Seq and analyzed the data using freely-available computational methods and resources. The aim was to identify previously unannotated regions of the genome using RNA-Seq based expression profile to complement the existing annotation of this pathogen. Results Using the Illumina Genome Analyzer, we generated 9,055,826 reads (average length ~76 bp) and aligned them to the reference genome using Bowtie. The transcribed regions were analyzed using SAMTOOLS and custom Perl scripts in conjunction with BLAST searches and available gene annotation information. The single nucleotide resolution map enabled the identification of 14 novel protein coding regions as well as 44 potential novel sRNA. The basal transcription profile revealed that 2,506 of the 2,837 annotated regions were expressed in vitro, at 95.25% coverage, representing all broad functional gene categories in the genome. The expression profile also helped identify 518 potential operon structures involving 1,086 co-expressed pairs. We also identified 11 proteins with mutated/alternate start codons. Conclusions The application of RNA-Seq based transcriptome profiling to structural gene annotation helped correct existing annotation errors and identify potential novel protein coding regions and sRNA. We used computational tools to predict regulatory elements such as promoters and terminators associated with the novel expressed regions for further characterization of these novel functional elements. Our study complements the existing structural annotation of Mannheimia haemolytica PHL213 based on experimental evidence. Given the role of sRNA in virulence gene regulation and stress response, potential novel sRNA described in this study can form the framework for future studies to determine the role of sRNA, if any, in M. haemolytica pathogenesis. PMID:23046475

2012-01-01

33

Rapid identification and strain-typing of respiratory pathogens for epidemic surveillance  

PubMed Central

Epidemic respiratory infections are responsible for extensive morbidity and mortality within both military and civilian populations. We describe a high-throughput method to simultaneously identify and genotype species of bacteria from complex mixtures in respiratory samples. The process uses electrospray ionization mass spectrometry and base composition analysis of PCR amplification products from highly conserved genomic regions to identify and determine the relative quantity of pathogenic bacteria present in the sample. High-resolution genotyping of specific species is achieved by using additional primers targeted to highly variable regions of specific bacterial genomes. This method was used to examine samples taken from military recruits during respiratory disease outbreaks and for follow up surveillance at several military training facilities. Analysis of respiratory samples revealed high concentrations of pathogenic respiratory species, including Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pyogenes. When S. pyogenes was identified in samples from the epidemic site, the identical genotype was found in almost all recruits. This analysis method will provide information fundamental to understanding the polymicrobial nature of explosive epidemics of respiratory disease. PMID:15911764

Ecker, David J.; Sampath, Rangarajan; Blyn, Lawrence B.; Eshoo, Mark W.; Ivy, Cristina; Ecker, Joseph A.; Libby, Brian; Samant, Vivek; Sannes-Lowery, Kristin A.; Melton, Rachael E.; Russell, Kevin; Freed, Nikki; Barrozo, Chris; Wu, Jianguo; Rudnick, Karl; Desai, Anjali; Moradi, Emily; Knize, Duane J.; Robbins, David W.; Hannis, James C.; Harrell, Patina M.; Massire, Christian; Hall, Thomas A.; Jiang, Yun; Ranken, Raymond; Drader, Jared J.; White, Neill; McNeil, John A.; Crooke, Stanley T.; Hofstadler, Steven A.

2005-01-01

34

Genomic Investigations Unmask Mycoplasma amphoriforme, a New Respiratory Pathogen  

PubMed Central

Background.?Mycoplasma amphoriforme has been associated with infection in patients with primary antibody deficiency (PAD). Little is known about the natural history of infection with this organism and its ability to be transmitted in the community. Methods.?The bacterial load was estimated in sequential sputum samples from 9 patients by quantitative polymerase chain reaction. The genomes of all available isolates, originating from patients in the United Kingdom, France, and Tunisia, were sequenced along with the type strain. Genomic data were assembled and annotated, and a high-resolution phylogenetic tree was constructed. Results.?By using high-resolution whole-genome sequencing (WGS) data, we show that patients can be chronically infected with M. amphoriforme manifesting as a relapsing-remitting bacterial load, interspersed by periods when the organism is undetectable. Importantly, we demonstrate transmission of strains within a clinical environment. Antibiotic resistance mutations accumulate in isolates taken from patients who received multiple courses of antibiotics. Conclusions.?Mycoplasma amphoriforme isolates form a closely related species responsible for a chronic relapsing and remitting infection in PAD patients in the United Kingdom and from immunocompetent patients in other countries. We provide strong evidence of transmission between patients attending the same clinic, suggesting that screening and isolation may be necessary for susceptible patients. This work demonstrates the critical role that WGS can play in rapidly unraveling the biology of a novel pathogen. PMID:25344534

Gillespie, Stephen H.; Ling, Clare L.; Oravcova, Katarina; Pinheiro, Miguel; Wells, Louise; Bryant, Josephine M.; McHugh, Timothy D.; Bébéar, Cecile; Webster, David; Harris, Simon R.; Seth-Smith, Helena M. B.; Thomson, Nicholas R.

2015-01-01

35

Respiratory cryptosporidiosis in HIV-seronegative children, Uganda: potential for respiratory transmission  

PubMed Central

Background Respiratory cryptosporidiosis is recognized as a late-stage complication in persons with HIV/AIDS. However, respiratory signs and symptoms are common in otherwise healthy children with intestinal cryptosporidiosis, suggesting that respiratory infection may occur in immunocompetent hosts. Methods We recruited children aged 9–36 months who presented with diarrhea to Mulago Hospital in Kampala, Uganda. Children with Cryptosporidium-positive and -negative stools were selected for further evaluation, including sputum induction in those with cough or unexplained respiratory signs, and collection of saliva and blood. Sputum samples were subjected to comprehensive bacteriological testing, and both sputum and saliva were tested for Cryptosporidium by nested-PCR. Results Of 926 fecal samples screened, 116 (12.5%) were Cryptosporidium positive. Seventeen of 48 (35.4%) sputum samples tested from stool-positive children were positive for Cryptosporidium. Sixteen of the 17 children with confirmed respiratory cryptosporidiosis were HIV-seronegative and 10/17 (58.8%) children were normally nourished. None of the 12 sputum specimens tested from stool-negative children were Cryptosporidium positive (p=0.013 compared to stool-positive children). Parasite DNA was only detected in 2/103 (1.9%) saliva samples (p<0.0001 compared to sputum). Conclusions Respiratory cryptosporidiosis was documented in one third of HIV-seronegative children who were tested. These novel findings suggest the potential for respiratory transmission. This study is registered with ClinicalTrials.gov, number NCT00507871. PMID:20377408

Mor, Siobhan M.; Tumwine, James K.; Ndeezi, Grace; Srinivasan, Maheswari G.; Kaddu-Mulindwa, Deogratias H.; Tzipori, Saul; Griffiths, Jeffrey K.

2010-01-01

36

Genetic variation and pathogenicity of highly virulent porcine reproductive and respiratory syndrome virus emerging in China  

Microsoft Academic Search

A highly pathogenic swine disease designated as ‘porcine high fever disease (PHFD)’ appeared recently in China. Porcine reproductive\\u000a and respiratory syndrome virus (PRRSV) was identified as an agent associated with PHFD, and two discontiguous sequence deletions\\u000a were identified as a genetic marker in the Nsp2 region of the viral genome. To examine PHFD in Shandong province, a total\\u000a of 10

J. Wu; J. Li; F. Tian; S. Ren; M. Yu; J. Chen; Z. Lan; X. Zhang; Dongwan Yoo; Jinbao Wang

2009-01-01

37

Comparison of commercial systems for extraction of nucleic acids from DNA/RNA respiratory pathogens.  

PubMed

This study compared six automated nucleic acid extraction systems and one manual kit for their ability to recover nucleic acids from human nasal wash specimens spiked with five respiratory pathogens, representing Gram-positive bacteria (Streptococcus pyogenes), Gram-negative bacteria (Legionella pneumophila), DNA viruses (adenovirus), segmented RNA viruses (human influenza virus A), and non-segmented RNA viruses (respiratory syncytial virus). The robots and kit evaluated represent major commercially available methods that are capable of simultaneous extraction of DNA and RNA from respiratory specimens, and included platforms based on magnetic-bead technology (KingFisher mL, Biorobot EZ1, easyMAG, KingFisher Flex, and MagNA Pure Compact) or glass fiber filter technology (Biorobot MDX and the manual kit Allprep). All methods yielded extracts free of cross-contamination and RT-PCR inhibition. All automated systems recovered L. pneumophila and adenovirus DNA equivalently. However, the MagNA Pure protocol demonstrated more than 4-fold higher DNA recovery from the S. pyogenes than other methods. The KingFisher mL and easyMAG protocols provided 1- to 3-log wider linearity and extracted 3- to 4-fold more RNA from the human influenza virus and respiratory syncytial virus. These findings suggest that systems differed in nucleic acid recovery, reproducibility, and linearity in a pathogen specific manner. PMID:21034773

Yang, Genyan; Erdman, Dean E; Kodani, Maja; Kools, John; Bowen, Michael D; Fields, Barry S

2011-01-01

38

Randomized clinical trial to evaluate the pathogenicity of Bibersteinia trehalosi in respiratory disease among calves  

PubMed Central

Background Bibersteinia trehalosi causes respiratory disease in ruminants particularly in wild and domestic sheep. Recently, there has been an increased number of B. trehalosi isolates obtained from diagnostic samples from bovine respiratory disease cases. This study evaluated the role of B. trehalosi in bovine respiratory disease using an intra-tracheal inoculation model in calves. Thirty six cross bred 2–3 month old dairy calves were inoculated intra-tracheally with either leukotoxin negative B. trehalosi, leukotoxin positive B. trehalosi isolate, Mannheimia haemolytica, a combination of leukotoxin negative B. trehalosi and M. haemolytica or negative control. Calves were euthanized and necropsy performed on day 10 of study. Results B. trehalosi inoculated calves did not have increased lung involvement compared to control calves. Additionally, B. trehalosi was only cultured once from the lungs of inoculated calves at necropsy. Conclusions Based on these findings B. trehalosi may not be a primary pathogen of respiratory disease in cattle. Culture of B. trehalosi from diagnostic submissions should not be immediately identified as a primary cause of respiratory disease. PMID:24745347

2014-01-01

39

Emergence and pathogenicity of highly pathogenic Porcine reproductive and respiratory syndrome virus in Vientiane, Lao People's Democratic Republic.  

PubMed

Highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRS) characterized by high fever, high morbidity, and high mortality in pigs of all ages emerged in China in 2006 and spread rapidly throughout Southeast Asia. In July 2010, a highly contagious swine disease with clinical signs similar to those of HP-PRRS was observed in the Lao People's Democratic Republic (Lao PDR). A field investigation covering 8 pig farms and 1 slaughterhouse in 7 different districts in the capital city of Vientiane was conducted to identify the disease. Total mortality rates ranged from 6.02% in boars to 91.28% in piglets (mean 54.15%) across the farms investigated. Emergence of the HP-PRRS virus (HP-PRRSV) in Lao PDR was confirmed using real-time reverse transcription polymerase chain reaction as well as virus isolation and identification. An animal inoculation study was performed to characterize the HP-PRRSV responsible for this outbreak. Isolate Laos 1.13 was inoculated into 70-day-old specific pathogen-free pigs to study pathogenicity. Clinical signs of high fever, rubefaction, respiratory distress, nervous symptoms, and diarrhea were observed in inoculated pigs, as well as pathological hemorrhagic lesions consolidated in the lungs. Morbidity and mortality were 100% and 60%, respectively, in inoculated pigs. HP-PRRSV was re-isolated from the inoculated pigs. Results suggested that the newly emerged HP-PRRSV was responsible for recent outbreaks of the swine disease in Lao PDR. The current report highlights the importance of continuous surveillance in neighboring countries to prevent introduction of PRRS to new regions. PMID:22379051

Ni, Jianqiang; Yang, Shibiao; Bounlom, Douangngeun; Yu, Xiuling; Zhou, Zhi; Song, Jianling; Khamphouth, Vongxay; Vatthana, Theppannga; Tian, Kegong

2012-03-01

40

Global reemergence of enterovirus D68 as an important pathogen for acute respiratory infections.  

PubMed

We previously detected enterovirus D68 (EV-D68) in children with severe acute respiratory infections in the Philippines in 2008-2009. Since then, the detection frequency of EV-D68 has increased in different parts of the world, and EV-D68 is now recognized as a reemerging pathogen. However, the epidemiological profile and clinical significance of EV-D68 is yet to be defined, and the virological characteristics of EV-D68 are not fully understood. Recent studies have revealed that EV-D68 is detected among patients with acute respiratory infections of differing severities ranging from mild upper respiratory tract infections to severe pneumonia including fatal cases in pediatric and adult patients. In some study sites, the EV-D68 detection rate was higher among patients with lower respiratory tract infections than among those with upper respiratory tract infections, suggesting that EV-D68 infections are more likely to be associated with severe respiratory illnesses. EV-D68 strains circulating in recent years have been divided into three distinct genetic lineages with different antigenicity. However, the association between genetic differences and disease severity, as well as the occurrence of large-scale outbreaks, remains elusive. Previous studies have revealed that EV-D68 is acid sensitive and has an optimal growth temperature of 33?°C. EV-D68 binds to ?2,6-linked sialic acids; hence, it is assumed that it has an affinity for the upper respiratory track where these glycans are present. However, the lack of suitable animal model constrains comprehensive understanding of the pathogenesis of EV-D68. © 2014 The Authors. Reviews in Medical Virology published by John Wiley & Sons Ltd. PMID:25471236

Imamura, Tadatsugu; Oshitani, Hitoshi

2014-12-01

41

The role of multiplex PCR test in identification of bacterial pathogens in lower respiratory tract infections  

PubMed Central

Objectives: Lower respiratory tract infection is one of the most important causes of morbidity and mortality. However establishing a microbial diagnosis for patients with lower respiratory tract infection is still challenging and is often achieved in only half of cases by conventional methods. This study was designed to compare the fast responsive PCR method with the culture method in lower respiratory tract infections and to evaluate the reliability of multiplex PCR method. Methods: One hundred ninety seven patients with the symptoms of acute lower respiratory tract infection, and diagnosed with community-acquired pneumonia, acute exacerbation of chronic obstructive pulmonary disease and exacerbations of bronchiectasis were included in the study. Both culture and PCR methods was performed for the isolation of most commonly seen bacteria, from sputum, nasopharyngeal swabs and bronchoalveolar lavage fluid samples. Results: While at least one bacterial isolation was determined in 62 (31.5%) of all patients with culture method, this number increased to 125 (63.5%) with multiplex PCR. The bacteria most commonly identified by PCR were S. pneumoniae (32%) and H. influenzae (31%). There was a significant difference between PCR and culture in terms of multi-factor detection rates (p<0.005). Multiple bacteria were detected in only two cases in cultures; however, multiple pathogens were detected in 47 cases with PCR. Conclusions: Conventional methods, such as culture and serology are not always adequate to detect the pathogens in lower respiratory tract. Real-time PCR assays proved highly sensitive and rapid. The prevalence of bacteria and multiple agent detected by real-time PCR compared with culture was substantially higher. Widespread use of PCR methods, by providing the immediate and appropriate ''agent specific antibiotic treatment'' of LRTI, will help reduce failure and contributes to a reduction in antibiotic resistance. PMID:25225517

Aydemir, Ozlem; Aydemir, Yusuf; Ozdemir, Mehmet

2014-01-01

42

Infection of United States swine with a Chinese highly pathogenic strain of porcine reproductive and respiratory syndrome virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

To assess the pathogenic effects of Type 2 highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) on healthy 10-week old commercial swine in the United States, viral kinetics and resultant disease caused by intranasal inoculation of such virus rescued from an infectious clo...

43

Pathogenic influenza B virus in the ferret model establishes lower respiratory tract infection.  

PubMed

Influenza B viruses have become increasingly more prominent during influenza seasons. Influenza B infection is typically considered a mild disease and receives less attention than influenza A, but has been causing 20 to 50?% of the total influenza incidence in several regions around the world. Although there is increasing evidence of mid to lower respiratory tract diseases such as bronchitis and pneumonia in influenza B patients, little is known about the pathogenesis of recent influenza B viruses. Here we investigated the clinical and pathological profiles of infection with strains representing the two current co-circulating B lineages (B/Yamagata and B/Victoria) in the ferret model. Specifically, we studied two B/Victoria (B/Brisbane/60/2008 and B/Bolivia/1526/2010) and two B/Yamagata (B/Florida/04/2006 and B/Wisconsin/01/2010) strain infections in ferrets and observed strain-specific but not lineage-specific pathogenicity. We found B/Brisbane/60/2008 caused the most severe clinical illness and B/Brisbane/60/2008 and the B/Yamagata strains instigated pathology in the middle to lower respiratory tract. Importantly, B/Brisbane/60/2008 established efficient lower respiratory tract infection with high viral burden. Our phylogenetic analyses demonstrate profound reassortment among recent influenza B viruses, which indicates the genetic make-up of B/Brisbane/60/2008 differs from the other strains. This may explain the pathogenicity difference post-infection in ferrets. PMID:24989173

Huang, Stephen S H; Banner, David; Paquette, Stephane G; Leon, Alberto J; Kelvin, Alyson A; Kelvin, David J

2014-10-01

44

Potential lactoferrin activity against pathogenic viruses.  

PubMed

Lactoferrin (LF) is an 80-kDa globular glycoprotein with high affinity for metal ions, particularly for iron. This protein possesses many biological functions, including the binding and release of iron and serves as one of the important components of the innate immune system, where it acts as a potent inhibitor of several pathogens. LF has efficacious antibacterial and antiviral activities against a wide range of Gram-positive and Gram-negative bacteria and against both naked and enveloped DNA and RNA viruses. In its antiviral pursuit, LF acts predominantly at the acute phase of the viral infection or even at the intracellular stage, as in hepatitis C virus infection. LF inhibits the entry of viral particles into host cells, either by direct attachment to the viral particles or by blocking their cellular receptors. This wide range of activities may be attributed to the capacity of LF to bind iron and its ability to interfere with the cellular receptors of both hosts and pathogenic microbes. PMID:25282173

Redwan, Elrashdy M; Uversky, Vladimir N; El-Fakharany, Esmail M; Al-Mehdar, Hussein

2014-10-01

45

Evaluation of OPC-17116 against important pathogens that cause respiratory tract infections.  

PubMed Central

The antibacterial activity of OPC-17116, a new fluoroquinolone antibacterial agent, against important pathogens that cause respiratory tract infections was evaluated in vitro and in vivo and compared with those of ciprofloxacin, ofloxacin, and norfloxacin. The pharmacokinetic profiles of OPC-17116 were studied in both mice and rats given the drug orally at doses of 50 and 40 mg/kg of body weight, respectively. OPC-17116 showed a high degree of distribution in the lung tissues of both species, with maximum concentrations of 29.6 and 32.0 micrograms/g, respectively. Furthermore, the drug concentrations in lung tissue were about 10 to 15 times greater than the concentrations in plasma. OPC-17116 showed potent antibacterial activity against such pathogens as Staphylococcus aureus, Streptococcus pneumoniae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Haemophilus influenzae, and Moraxella catarrhalis. The MICs of this compound for 90% of these organisms except methicillin-resistant S. aureus and P. aeruginosa ranged from < or = 0.006 to 0.78 microgram/ml. The in vitro antibacterial activity of OPC-17116 was reflected by the efficacy of a single oral dose against systemic bacterial infections in mice. OPC-17116 showed a superior effect against gram-positive bacteria, H. influenzae, and M. catarrhalis. In comparison with the other reference compounds, the efficacy of OPC-17116 was less than that of ciprofloxacin against K. pneumoniae and P. aeruginosa. OPC-17116 showed a greater therapeutic effect than the other drugs against experimental acute pneumonia caused by these organisms in mice or rats. This excellent therapeutic effect against respiratory tract infections may be a result of its high level of distribution in lung tissue. PMID:7840567

Wakebe, H; Imada, T; Yoneda, H; Mukai, F; Ohguro, K; Ohmori, K; Tamaoka, H; Yabuuchi, Y

1994-01-01

46

The Laboratory Diagnosis of Severe Acute Respiratory Syndrome: Emerging Laboratory Tests for an Emerging Pathogen  

PubMed Central

The 2003 pandemic of Severe Acute Respiratory Syndrome (SARS) profiled the ability of modern diagnostic microbiology and molecular biology to identify, isolate and characterize, within weeks, a previously unknown viral infectious pathogen. The culprit, SARS coronavirus (SARS-CoV), was detected in patient specimens by traditional cell culture using an unusual cell line for respiratory viruses, Vero E6, and by reverse transcriptase polymerase chain reaction (RT-PCR) targeting the polymerase 1 B region of the genome. In addition, serologic assays were rapidly developed, and the genome of this large virus was sequenced within one month of its spread to North America. At the present time, diagnostics have progressed to the point that RT-PCR has a sensitivity approaching 80% within the first few days of onset of illness, while serology has a sensitivity close to 100% on convalescent sera taken >21 days after illness onset. Viral culture remains a method confined to biosafety level III laboratories. The specificity of RT-PCR and serology remains to be conclusively defined, but in most studies to date seems to be >90%. Serologic cross-reactivity with human coronaviruses causing the common cold may be a problem with some serologic assays. The early development of SARS-CoV diagnostics is now being replaced by refinement and optimization of these assays. Although at the present time we do not have a test that will definitively rule in or rule out SARS at the time of initial presentation of a patient with a respiratory infection, modifications of existing assays will hopefully result in our ability to make this diagnosis with a high degree of accuracy in the future. PMID:18458711

Richardson, Susan E.; Tellier, Raymond; Mahony, James

2004-01-01

47

Detection and Typing of Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus by Multiplex Real-Time RT-PCR  

Microsoft Academic Search

Porcine reproductive and respiratory syndrome (PRRS) causes economic losses in the pig industry worldwide, and PRRS viruses (PRRSV) are classified into the two distinct genotypes “North American (NA, type 2)” and “European (EU, type 1)”. In 2006, a highly pathogenic NA strain of PRRSV (HP-PRRSV), characterized by high fever as well as high morbidity and mortality, emerged in swine farms

Kerstin Wernike; Bernd Hoffmann; Malte Dauber; Elke Lange; Horst Schirrmeier; Martin Beer

2012-01-01

48

The vOTU domain of highly-pathogenic porcine reproductive and respiratory syndrome virus displays a differential substrate preference  

Technology Transfer Automated Retrieval System (TEKTRAN)

Arterivirus genus member Porcine reproductive and respiratory syndrome virus (PRRSV) causes an economically devastating disease that presents global concerns to the pork industry, which have been exacerbated by the emergence of a highly pathogenic PRRSV strain (HP-PRRSV) in China and Southeast Asia....

49

Respiratory viral pathogens among Singapore military servicemen 2009 – 2012: epidemiology and clinical characteristics  

PubMed Central

Background Few studies have comprehensively described tropical respiratory disease surveillance in military populations. There is also a lack of studies comparing clinical characteristics of the non-influenza pathogens with influenza and amongst themselves. Methods From May 2009 through October 2012, 7733 consenting cases of febrile respiratory illness (FRI) (temperature [greater than or equal to]37.5degreesC with cough or sorethroat) and controls in the Singapore military had clinical data and nasal washes collected prospectively. Nasal washes underwent multiplex PCR, and the analysis was limited to viral mono-infections. Results 49% of cases tested positive for at least one virus, of whom 10% had multiple infections. 53% of the FRI cases fulfilled the definition of influenza-like illness (ILI), of whom 52% were positive for at least one virus. The most frequent etiologies for mono-infections among FRI cases were Influenza A(H1N1)pdm09 (13%), Influenza B (13%) and coxsackevirus (9%). The sensitivity, specificity, positive predictive value and negative predictive value of ILI for influenza among FRI cases were 72%, 48%, 40% and 69% respectively. On logistic regression, there were marked differences in the prevalence of different symptoms and signs between viruses with fever more prevalent amongst influenza and adenovirus infections than other viruses. Conclusion There are multiple viral etiologies for FRI and ILI with differing clinical symptoms in the Singapore military. Influenza and coxsackevirus were the most common etiology for FRI, while influenza and adenoviruses displayed the most febrile symptoms. Further studies should explore these differences and possible interventions. PMID:24735158

2014-01-01

50

Genes controlling vaccine responses and disease resistance to respiratory viral pathogens in cattle  

PubMed Central

Farm animals remain at risk of endemic, exotic and newly emerging viruses. Vaccination is often promoted as the best possible solution, and yet for many pathogens, either there are no appropriate vaccines or those that are available are far from ideal. A complementary approach to disease control may be to identify genes and chromosomal regions that underlie genetic variation in disease resistance and response to vaccination. However, identification of the causal polymorphisms is not straightforward as it generally requires large numbers of animals with linked phenotypes and genotypes. Investigation of genes underlying complex traits such as resistance or response to viral pathogens requires several genetic approaches including candidate genes deduced from knowledge about the cellular pathways leading to protection or pathology, or unbiased whole genome scans using markers spread across the genome. Evidence for host genetic variation exists for a number of viral diseases in cattle including bovine respiratory disease and anecdotally, foot and mouth disease virus (FMDV). We immunised and vaccinated a cattle cross herd with a 40-mer peptide derived from FMDV and a vaccine against bovine respiratory syncytial virus (BRSV). Genetic variation has been quantified. A candidate gene approach has grouped high and low antibody and T cell responders by common motifs in the peptide binding pockets of the bovine major histocompatibility complex (BoLA) DRB3 gene. This suggests that vaccines with a minimal number of epitopes that are recognised by most cattle could be designed. Whole genome scans using microsatellite and single nucleotide polymorphism (SNP) markers has revealed many novel quantitative trait loci (QTL) and SNP markers controlling both humoral and cell-mediated immunity, some of which are in genes of known immunological relevance including the toll-like receptors (TLRs). The sequencing, assembly and annotation of livestock genomes and is continuing apace. In addition, provision of high-density SNP chips should make it possible to link phenotypes with genotypes in field populations without the need for structured populations or pedigree information. This will hopefully enable fine mapping of QTL and ultimate identification of the causal gene(s). The research could lead to selection of animals that are more resistant to disease and new ways to improve vaccine efficacy. PMID:21621277

Glass, Elizabeth J.; Baxter, Rebecca; Leach, Richard J.; Jann, Oliver C.

2012-01-01

51

A Modeling-Derived Hypothesis on Chronicity in Respiratory Diseases: Desensitized Pathogen Recognition Secondary to Hyperactive IRAK/TRAF6 Signaling  

PubMed Central

Several chronic respiratory diseases exhibit hyperactive immune responses in the lung: abundant inflammatory mediators; infiltrating neutrophils, macrophages, lymphocytes and other immune cells; and increased level of proteases. Such diseases include cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD) and severe/neutrophilic asthma. Paradoxically, patients with these diseases are also susceptible to detrimental bacterial infection and colonization. In this paper, we seek to explain how a positive feedback mechanism via IL-8 could lead to desensitization of epithelial cells to pathogen recognition thus perpetuating bacterial colonization and chronic disease states in the lung. Such insight was obtained from mathematical modeling of the IRAK/TRAF6 signaling module, and is consistent with existing clinical evidence. The potential implications for targeted treatment regimes for these persistent respiratory diseases are explored. PMID:19390631

Zhang, Tingting; Song, Kyung W.; Hekmat-Nejad, Mohammad; Morris, David G.; Wong, Brian R.

2009-01-01

52

Vasoactive Intestinal Peptide Inhaled Agonists: Potential Role in Respiratory Therapeutics  

PubMed Central

Purpose of review: Vasoactive Intestinal Peptide (VIP) is a neuropeptide, expressed by lymphoid as well as neural cells, which has diverse effects on the cellular mediators of inflammation and immunity and is also a potent neurotransmitter. VIP seems to have a major role in the homeostasis of the respiratory system, while several studies, including clinical trials, suggest that VIP-inhaled agonists could be used in respiratory therapeutics. In this review, we provide an introduction to the field of VIP research geared to clinical and research pulmonologists. Recent Findings: As a neurotransmitter, VIP exerts a potent bronchodilatory and vasodilatory effect and also is supposed to induce the house-keeping mucus secretion by submucosal glands. On the other hand, it has immunomodulatory functions which include humoral immune response suppression, inhibition of vascular and bronchial remodeling and inflammation and attenuation of the cigarette smoke extract-induced apoptotic death of alveolar L2 cells. Recent research on a wide spectrum of lung diseases including asthma, chronic obstructive pulmonary disease, cystic fibrosis, pulmonary hypertension, and sarcoidosis indicates a potential therapeutic role of a VIP agonist. Simultaneously, novel stabilized inhaled VIP agonists and drug delivery systems have been proposed as a promising candidate alternative drug with minimized side effects. These data are supported by the results of certain, limited clinical trials which have already been conducted. Conclusion: Ongoing research continues to clarify the immunomodulatory effects of VIP and to confirm animal findings with human studies. A major challenge for investigators will be to determine whether stabilized inhaled-VIP agonists could be used in respiratory therapeutics. PMID:23935337

Mathioudakis, AG; Chatzimavridou-Grigoriadou, V; Evangelopoulou, E; Mathioudakis, GA

2013-01-01

53

Rapid Multiplex PCR Assay To Identify Respiratory Viral Pathogens: Moving Forward Diagnosing The Common Cold  

PubMed Central

Upper respiratory tract infections (URIs) can be a serious burden to the healthcare system. The majority of URIs are viral in etiology, but definitive diagnosis can prove difficult due to frequently overlapping clinical presentations of viral and bacterial infections, and the variable sensitivity, and lengthy turn-around time of viral culture. We tested new automated nested multiplex PCR technology, the FilmArray® system, in the TAMC department of clinical investigations, to determine the feasibility of replacing the standard viral culture with a rapid turn-around system. We conducted a feasibility study using a single-blinded comparison study, comparing PCR results with archived viral culture results from a convenience sample of cryopreserved archived nasopharyngeal swabs from acutely ill ED patients who presented with complaints of URI symptoms. A total of 61 archived samples were processed. Viral culture had previously identified 31 positive specimens from these samples. The automated nested multiplex PCR detected 38 positive samples. In total, PCR was 94.5% concordant with the previously positive viral culture results. However, PCR was only 63.4% concordant with the negative viral culture results, owing to PCR detection of 11 additional viral pathogens not recovered on viral culture. The average time to process a sample was 75 minutes. We determined that an automated nested multiplex PCR is a feasible alternative to viral culture in an acute clinical setting. We were able to detect at least 94.5% as many viral pathogens as viral culture is able to identify, with a faster turn-around time. PMID:24052914

Gordon, Sarah M; Elegino-Steffens, Diane U; Agee, Willie; Barnhill, Jason; Hsue, Gunther

2013-01-01

54

Potential for palivizumab interference with commercially available antibody-antigen based respiratory syncytial virus diagnostic assays.  

PubMed

Palivizumab is a monoclonal antibody indicated for the prevention of serious lower respiratory tract disease caused by respiratory syncytial virus infection in infants. The potential for palivizumab to interfere with commercially available respiratory syncytial virus diagnostic tests was demonstrated. Negative test results in palivizumab-treated subjects should be interpreted with caution and confirmed by a nucleic acid amplification-based assay. PMID:23584584

Deming, Damon J; Patel, Nita; McCarthy, Michael P; Mishra, Lalji; Shapiro, Alan M; Suzich, JoAnn A

2013-10-01

55

Helichrysum arenarium subsp. arenarium: phenolic composition and antibacterial activity against lower respiratory tract pathogens.  

PubMed

The aim of this study was to investigate the phenolic content and antibacterial activity of the methanol extract from Helichrysum arenarium (L.) Moench subsp. arenarium inflorescences against lower respiratory tract pathogens (standard strains and clinical isolates). The extract was characterised by a total phenolic content of 160.17 mg/g. Several caffeic acid conjugates (chlorogenic acid and dicaffeoylquinic acids) and flavonoids (apigenin, naringenin, apigenin-7-O-glucoside and naringenin-O-hexosides) were identified as major constituents by HPLC-DAD-ESI-MS. Staphylococcus aureus ATCC 25923 was more susceptible to Helichrysum extract than Streptococcus pneumoniae ATCC 49619 (minimum inhibitory concentration [MIC] = 0.62  and 1.25 mg/mL, respectively). The extract exhibited similar antibacterial effects against methicillin-resistant S. aureus and penicillin-resistant S. pneumoniae clinical isolates (MIC = 2.5 mg/mL) displaying a higher activity against ampicillin-resistant Moraxella catarrhalis isolate (MIC = 0.15 mg/mL). The combination with ciprofloxacin exhibited additivity against both standard strains (fractional inhibitory concentration [FIC] index = 0.75 and 0.73) and S. aureus isolates (FIC index = 0.62) and synergy against S. pneumoniae isolates (FIC index = 0.5). PMID:24931335

Gradinaru, Adina C; Silion, Mihaela; Trifan, Adriana; Miron, Anca; Aprotosoaie, Ana C

2014-01-01

56

Antimicrobial susceptibility among community-acquired respiratory tract pathogens in the USA: data from PROTEKT US 2000–01  

Microsoft Academic Search

Objectives. The PROTEKT US surveillance program (Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin in the United States) commenced in 2000 to document the emergence and spread of antimicrobial resistance among respiratory tract pathogens in the United States.Methods. During 2000–2001, 206 centers from 154 cities\\/metropolitan areas collected 16,727 clinical isolates (Streptococcus pneumoniae, n=10103, Streptococcus pyogenes, n=3918, Haemophilus influenzae,

Gary V Doern; Steve D Brown

2004-01-01

57

Bdellovibrios, potential biocontrol bacteria against pathogenic Aeromonas hydrophila.  

PubMed

Recent studies have revealed that the use of bdellovibrios is an alternative to control bacteriosis. However, no bdellovibrios are available against Aeromonas hydrophila infections in sturgeons. In the present study, a potential Bdellovibrio strain F16 was isolated from sturgeon gut samples, using a sturgeon-pathogenic A. hydrophila as the prey bacterium. It was initially identified as a Bdellovibrio strain using morphological characteristics and specific PCR amplification, and confirmed to be Bdellovibrio sp. strain ETB (GenBank Accession No. DQ302728) and Bdellovibrio bacteriovorus strain SRA9 (GenBank Accession No. AF263833) by phylogenetic analysis. In addition, it was shown to be safe for mammalians and sturgeons, had a wide prey range, and exhibited significant bacteriolytic effects on the pathogenic A. hydrophila. To the best of our knowledge, this is the first report on a promising gut Bdellovibrio strain against pathogenic A. hydrophila. PMID:21864996

Cao, Haipeng; He, Shan; Wang, Huicong; Hou, Sanling; Lu, Liqun; Yang, Xianle

2012-01-27

58

Evaluation of yield of currently available diagnostics by sample type to optimize detection of respiratory pathogens in patients with a community-acquired pneumonia  

PubMed Central

Background For the detection of respiratory pathogens, the sampling strategy may influence the diagnostic yield. Ideally, samples from the lower respiratory tract are collected, but they are difficult to obtain. Objectives In this study, we compared the diagnostic yield in sputum and oropharyngeal samples (OPS) for the detection of respiratory pathogens in patients with community-acquired pneumonia (CAP), with the objective to optimize our diagnostic testing algorithm. Methods Matched sputum samples, OPS, blood cultures, serum, and urine samples were taken from patients (>18 years) with CAP and tested for the presence of possible respiratory pathogens using bacterial cultures, PCR for 17 viruses and five bacteria and urinary antigen testing. Results When using only conventional methods, that is, blood cultures, sputum culture, urinary antigen tests, a pathogen was detected in 49·6% of patients (n = 57). Adding molecular detection assays increased the yield to 80%. A pathogen was detected in 77 of the 115 patients in OPS or sputum samples by PCR. The sensitivity of the OPS was lower than that of the sputum samples (57% versus 74%). In particular, bacterial pathogens were more often detected in sputum samples. The sensitivity of OPS for the detection of most viruses was higher than in sputum samples (72% versus 66%), except for human rhinovirus and respiratory syncytial virus. Conclusion Addition of PCR on both OPS and sputum samples significantly increased the diagnostic yield. For molecular detection of bacterial pathogens, a sputum sample is imperative, but for detection of most viral pathogens, an OPS is sufficient. PMID:23957707

Huijskens, Elisabeth G W; Rossen, John W A; Kluytmans, Jan A J W; Zanden, Adri G M; Koopmans, Marion

2014-01-01

59

Serologic survey for pathogens potentially affecting pronghorn (Antilocapra americana) fawn recruitment in Arizona, USA.  

PubMed

During the 1990s, pronghorn (Antilocapra americana) populations declined in Arizona, USA. To investigate potential causes of decline, we collected blood samples from hunter-harvested male pronghorn from 2001 to 2003 on four Arizona sites. Sera were tested for antibody to parainfluenza virus type 3 (PI3), bovine viral diarrhea virus, infectious bovine rhinotracheitis virus, bovine respiratory syncytial virus, epizootic hemorrhagic disease virus (EHDV), bluetongue virus (BTV), and Chlamydia psittaci. Antibody against PI3 was found in 33% of the samples, whereas antibody against BTV/EHDV was found in 77%. Antibodies to other pathogens were found at low prevalence rates. Although pronghorn decline in Arizona is probably not directly related to disease, potential reproductive effects of BTV/EHDV and PI3 infection on pronghorn in Arizona merit further study. PMID:17255453

Dubay, Shelli A; Noon, Ted H; deVos, James C; Ockenfels, Richard A

2006-10-01

60

Prevalence of upper respiratory pathogens in four management models for unowned cats in the Southeast United States.  

PubMed

Upper respiratory infection (URI) is a pervasive problem in cats and impacts the capacity and cost of sheltering programs. This study determined the pattern of respiratory pathogens in cats with and without clinical signs of URI in four different models for managing unowned cats, namely, (1) short-term animal shelters (STS), (2) long-term sanctuaries (LTS), (3) home-based foster care programs (FCP), and (4) trap-neuter-return programs for community cats (TNR). Conjunctival and oropharyngeal swabs from 543 cats, approximately half of which showed clinical signs of URI, were tested for feline herpes virus-1 (FHV), feline calicivirus (FCV), Chlamydia felis, Bordetella bronchiseptica, Mycoplasma felis, and canine influenza virus by real-time PCR. FHV (59%, 41%) and B. bronchiseptica (33%, 24%) were more prevalent in both clinically affected and nonclinical cats, respectively, in STS than other management models. FCV (67%, 51%) and M. felis (84%, 86%) were more prevalent in LTS than any other management model. Clinically affected cats in FCP were more likely to carry FHV (23%, 6%), C. felis (24%, 10%), or M. felis (58%, 38%) than were nonclinical cats. Clinically affected cats in TNR were more likely to carry FCV (55%, 36%) or C. felis (23%, 4%) than were nonclinical cats. The prevalence of individual pathogens varied between different management models, but the majority of the cats in each model carried one or more respiratory pathogens regardless of clinical signs. Both confined and free-roaming cats are at risk of developing infectious respiratory disease and their health should be protected by strategic vaccination, appropriate antibiotic therapy, effective biosecurity, feline stress mitigation, and alternatives to high-density confinement. PMID:24923756

McManus, C M; Levy, J K; Andersen, L A; McGorray, S P; Leutenegger, C M; Gray, L K; Hilligas, J; Tucker, S J

2014-08-01

61

Upper Respiratory Tract Microbial Communities, Acute Otitis Media Pathogens, and Antibiotic Use in Healthy and Sick Children  

PubMed Central

The composition of the upper respiratory tract microbial community may influence the risk for colonization by the acute otitis media (AOM) pathogens Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. We used culture-independent methods to describe upper respiratory tract microbial communities in healthy children and children with upper respiratory tract infection with and without concurrent AOM. Nasal swabs and data were collected in a cross-sectional study of 240 children between 6 months and 3 years of age. Swabs were cultured for S. pneumoniae, and real-time PCR was used to identify S. pneumoniae, H. influenzae, and M. catarrhalis. The V1-V2 16S rRNA gene regions were sequenced using 454 pyrosequencing. Microbial communities were described using a taxon-based approach. Colonization by S. pneumoniae, H. influenzae, and M. catarrhalis was associated with lower levels of diversity in upper respiratory tract flora. We identified commensal taxa that were negatively associated with colonization by each AOM bacterial pathogen and with AOM. The balance of these relationships differed according to the colonizing AOM pathogen and history of antibiotic use. Children with antibiotic use in the past 6 months and a greater abundance of taxa, including Lactococcus and Propionibacterium, were less likely to have AOM than healthy children (odds ratio [OR], 0.46; 95% confidence interval [CI], 0.25 to 0.85). Children with no antibiotic use in the past 6 months, a low abundance of Streptococcus and Haemophilus, and a high abundance of Corynebacterium and Dolosigranulum were less likely to have AOM (OR, 0.51; 95% CI, 0.31 to 0.83). An increased understanding of polymicrobial interactions will facilitate the development of effective AOM prevention strategies. PMID:22752171

Laufer, Alison S.; Gent, Janneane F.; Kong, Yong; Fennie, Kristopher P.; Metlay, Joshua P.

2012-01-01

62

Distribution of Indigenous Bacterial Pathogens and Potential Pathogens Associated with Roof-Harvested Rainwater  

PubMed Central

The harvesting of rainwater is gaining acceptance among many governmental authorities in countries such as Australia, Germany, and South Africa, among others. However, conflicting reports on the microbial quality of harvested rainwater have been published. To monitor the presence of potential pathogenic bacteria during high-rainfall periods, rainwater from 29 rainwater tanks was sampled on four occasions (during June and August 2012) in a sustainable housing project in Kleinmond, South Africa. This resulted in the collection of 116 harvested rainwater samples in total throughout the sampling period. The identities of the dominant, indigenous, presumptive pathogenic isolates obtained from the rainwater samples throughout the sampling period were confirmed through universal 16S rRNA PCR, and the results revealed that Pseudomonas (19% of samples) was the dominant genus isolated, followed by Aeromonas (16%), Klebsiella (11%), and Enterobacter (9%). PCR assays employing genus-specific primers also confirmed the presence of Aeromonas spp. (16%), Klebsiella spp. (47%), Legionella spp. (73%), Pseudomonas spp. (13%), Salmonella spp. (6%), Shigella spp. (27%), and Yersinia spp. (28%) in the harvested rainwater samples. In addition, on one sampling occasion, Giardia spp. were detected in 25% of the eight tank water samples analyzed. This study highlights the diverse array of pathogenic bacteria that persist in harvested rainwater during high-rainfall periods. The consumption of untreated harvested rainwater could thus pose a potential significant health threat to consumers, especially children and immunocompromised individuals, and it is recommended that harvested rainwater be treated for safe usage as an alternative water source. PMID:24487540

Dobrowsky, P. H.; De Kwaadsteniet, M.; Cloete, T. E.

2014-01-01

63

Analysis of the swine tracheobronchial lymphnode transcriptomic response to infection with a Chinese highly pathogenic strain of porcine reproductive and respiratory syndrome virus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Porcine reproductive and respiratory syndrome virus (PRRSV) is a major pathogen of swine worldwide. Emergence in 2006 of a novel highly pathogenic PRRSV (HP-PRRSV) isolate in China necessitated a comparative investigation into the host transcriptome response in tracheobronchial lymph nodes (TBLN) 14...

64

Secondary infection with Streptococcus suis serotype 7 increases the virulence of highly pathogenic porcine reproductive and respiratory syndrome virus in pigs  

Microsoft Academic Search

BACKGROUND: Porcine reproductive and respiratory syndrome virus (PRRSV) and Streptococcus suis are common pathogens in pigs. In samples collected during the porcine high fever syndrome (PHFS) outbreak in many parts of China, PRRSV and S. suis serotype 7 (SS7) have always been isolated together. To determine whether PRRSV-SS7 coinfection was the cause of the PHFS outbreak, we evaluated the pathogenicity

Min Xu; Shujie Wang; Linxi Li; Liancheng Lei; Yonggang Liu; Wenda Shi; Jiabin Wu; Liqin Li; Fulong Rong; Mingming Xu; Guangli Sun; Hua Xiang; Xuehui Cai

2010-01-01

65

A Network Integration Approach to Predict Conserved Regulators Related to Pathogenicity of Influenza and SARS-CoV Respiratory Viruses  

SciTech Connect

Respiratory infections stemming from influenza viruses and the Severe Acute Respiratory Syndrome corona virus (SARS-CoV) represent a serious public health threat as emerging pandemics. Despite efforts to identify the critical interactions of these viruses with host machinery, the key regulatory events that lead to disease pathology remain poorly targeted with therapeutics. Here we implement an integrated network interrogation approach, in which proteome and transcriptome datasets from infection of both viruses in human lung epithelial cells are utilized to predict regulatory genes involved in the host response. We take advantage of a novel “crowd-based” approach to identify and combine ranking metrics that isolate genes/proteins likely related to the pathogenicity of SARS-CoV and influenza virus. Subsequently, a multivariate regression model is used to compare predicted lung epithelial regulatory influences with data derived from other respiratory virus infection models. We predicted a small set of regulatory factors with conserved behavior for consideration as important components of viral pathogenesis that might also serve as therapeutic targets for intervention. Our results demonstrate the utility of integrating diverse ‘omic datasets to predict and prioritize regulatory features conserved across multiple pathogen infection models.

Mitchell, Hugh D.; Eisfeld, Amie J.; Sims, Amy; McDermott, Jason E.; Matzke, Melissa M.; Webb-Robertson, Bobbie-Jo M.; Tilton, Susan C.; Tchitchek, Nicholas; Josset, Laurence; Li, Chengjun; Ellis, Amy L.; Chang, Jean H.; Heegel, Robert A.; Luna, Maria L.; Schepmoes, Athena A.; Shukla, Anil K.; Metz, Thomas O.; Neumann, Gabriele; Benecke, Arndt; Smith, Richard D.; Baric, Ralph; Kawaoka, Yoshihiro; Katze, Michael G.; Waters, Katrina M.

2013-07-25

66

A Network Integration Approach to Predict Conserved Regulators Related to Pathogenicity of Influenza and SARS-CoV Respiratory Viruses  

PubMed Central

Respiratory infections stemming from influenza viruses and the Severe Acute Respiratory Syndrome corona virus (SARS-CoV) represent a serious public health threat as emerging pandemics. Despite efforts to identify the critical interactions of these viruses with host machinery, the key regulatory events that lead to disease pathology remain poorly targeted with therapeutics. Here we implement an integrated network interrogation approach, in which proteome and transcriptome datasets from infection of both viruses in human lung epithelial cells are utilized to predict regulatory genes involved in the host response. We take advantage of a novel “crowd-based” approach to identify and combine ranking metrics that isolate genes/proteins likely related to the pathogenicity of SARS-CoV and influenza virus. Subsequently, a multivariate regression model is used to compare predicted lung epithelial regulatory influences with data derived from other respiratory virus infection models. We predicted a small set of regulatory factors with conserved behavior for consideration as important components of viral pathogenesis that might also serve as therapeutic targets for intervention. Our results demonstrate the utility of integrating diverse ‘omic datasets to predict and prioritize regulatory features conserved across multiple pathogen infection models. PMID:23935999

Mitchell, Hugh D.; Eisfeld, Amie J.; Sims, Amy C.; McDermott, Jason E.; Matzke, Melissa M.; Webb-Robertson, Bobbi-Jo M.; Tilton, Susan C.; Tchitchek, Nicolas; Josset, Laurence; Li, Chengjun; Ellis, Amy L.; Chang, Jean H.; Heegel, Robert A.; Luna, Maria L.; Schepmoes, Athena A.; Shukla, Anil K.; Metz, Thomas O.; Neumann, Gabriele; Benecke, Arndt G.; Smith, Richard D.; Baric, Ralph S.; Kawaoka, Yoshihiro; Katze, Michael G.; Waters, Katrina M.

2013-01-01

67

Biomarkers of acute respiratory allergen exposure: Screening for sensitization potential  

SciTech Connect

Effective hazard screening will require the development of high-throughput or in vitro assays for the identification of potential sensitizers. The goal of this preliminary study was to identify potential biomarkers that differentiate the response to allergens vs non-allergens following an acute exposure in naive individuals. Female BALB/c mice received a single intratracheal aspiration exposure to Metarhizium anisopliae crude antigen (MACA) or bovine serum albumin (BSA) in Hank's Balanced Salt Solution (HBSS) or HBSS alone. Mice were terminated after 1, 3, 6, 12, 18 and 24 h. Bronchoalveolar lavage fluid (BALF) was evaluated to determine total and differential cellularity, total protein concentration and LDH activity. RNA was isolated from lung tissue for microarray analysis and qRT-PCR. MACA administration induced a rapid increase in BALF neutrophils, lymphocytes, eosinophils and total protein compared to BSA or HBSS. Microarray analysis demonstrated differential expression of genes involved in cytokine production, signaling, inflammatory cell recruitment, adhesion and activation in 3 and 12 h MACA-treated samples compared to BSA or HBSS. Further analyses allowed identification of approx 100 candidate biomarker genes. Eleven genes were selected for further assessment by qRT-PCR. Of these, 6 demonstrated persistently increased expression (Ccl17, Ccl22, Ccl7, Cxcl10, Cxcl2, Saa1), while C3ar1 increased from 6-24 h. In conclusion, a single respiratory exposure of mice to an allergenic mold extract induces an inflammatory response which is distinct in phenotype and gene transcription from the response to a control protein. Further validation of these biomarkers with additional allergens and irritants is needed. These biomarkers may facilitate improvements in screening methods.

Pucheu-Haston, Cherie M., E-mail: Pucheu-Haston.Cherie@epa.go [Curriculum in Toxicology, University of North Carolina-Chapel Hill, CB 7270, Chapel Hill, NC 27599-7270 (United States); Copeland, Lisa B.; Vallanat, Beena; Boykin, Elizabeth; Ward, Marsha D.W. [National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711 (United States)

2010-04-15

68

Microbial Diversity and Potential Pathogens in Ornamental Fish Aquarium Water  

PubMed Central

Ornamental fishes are among the most popular and fastest growing categories of pets in the United States (U.S.). The global scope and scale of the ornamental fish trade and growing popularity of pet fish in the U.S. are strong indicators of the myriad economic and social benefits the pet industry provides. Relatively little is known about the microbial communities associated with these ornamental fishes or the aquarium water in which they are transported and housed. Using conventional molecular approaches and next generation high-throughput amplicon sequencing of 16S ribosomal RNA gene hypervariable regions, we characterized the bacterial community of aquarium water containing common goldfish (Carassius auratus) and Chinese algae eaters (Gyrinocheilus aymonieri) purchased from seven pet/aquarium shops in Rhode Island and identified the presence of potential pathogens. Our survey identified a total of 30 phyla, the most common being Proteobacteria (52%), Bacteroidetes (18%) and Planctomycetes (6%), with the top four phyla representing >80% of all sequences. Sequences from our water samples were most closely related to eleven bacterial species that have the potential to cause disease in fishes, humans and other species: Coxiella burnetii, Flavobacterium columnare, Legionella birminghamensis, L. pneumophila, Vibrio cholerae, V. mimicus. V. vulnificus, Aeromonas schubertii, A. veronii, A. hydrophila and Plesiomonas shigelloides. Our results, combined with evidence from the literature, suggest aquarium tank water harboring ornamental fish are an understudied source for novel microbial communities and pathogens that pose potential risks to the pet industry, fishes in trade, humans and other species. PMID:22970112

Smith, Katherine F.; Schmidt, Victor; Rosen, Gail E.; Amaral-Zettler, Linda

2012-01-01

69

The Respiratory Syncytial Virus Fusion Protein and Neutrophils Mediate the Airway Mucin Response to Pathogenic Respiratory Syncytial Virus Infection  

PubMed Central

Respiratory syncytial virus (RSV) is the leading cause of death due to a viral etiology in infants. RSV disease is characterized by epithelial desquamation, neutrophilic bronchiolitis and pneumonia, and obstructive pulmonary mucus. It has been shown that infection of BALB/cJ mice with RSV clinical isolate A2001/2-20 (2-20) results in a higher early viral load, greater airway necrosis, and higher levels of interleukin-13 (IL-13) and airway mucin expression than infection with RSV laboratory strain A2. We hypothesized that the fusion (F) protein of RSV 2-20 is a mucus-inducing viral factor. In vitro, the fusion activity of 2-20 F but not that of A2 F was enhanced by expression of RSV G. We generated a recombinant F-chimeric RSV by replacing the F gene of A2 with the F gene of 2-20, generating A2–2-20F. Similar to the results obtained with the parent 2-20 strain, infection of BALB/cJ mice with A2–2-20F resulted in a higher early viral load and higher levels of subsequent pulmonary mucin expression than infection with the A2 strain. A2–2-20F infection induced greater necrotic airway damage and neutrophil infiltration than A2 infection. We hypothesized that the neutrophil response to A2–2-20F infection is involved in mucin expression. Antibody-mediated depletion of neutrophils in RSV-infected mice resulted in lower tumor necrosis factor alpha levels, fewer IL-13-expressing CD4 T cells, and less airway mucin production in the lung. Our data are consistent with a model in which the F and attachment (G) glycoprotein functional interaction leads to enhanced fusion and F is a key factor in airway epithelium infection, pathogenesis, and subsequent airway mucin expression. PMID:23843644

Stokes, Kate L.; Currier, Michael G.; Sakamoto, Kaori; Lee, Sujin; Collins, Peter L.; Plemper, Richard K.

2013-01-01

70

RNA-Seq Based Transcriptional Map of Bovine Respiratory Disease Pathogen “Histophilus somni 2336”  

PubMed Central

Genome structural annotation, i.e., identification and demarcation of the boundaries for all the functional elements in a genome (e.g., genes, non-coding RNAs, proteins and regulatory elements), is a prerequisite for systems level analysis. Current genome annotation programs do not identify all of the functional elements of the genome, especially small non-coding RNAs (sRNAs). Whole genome transcriptome analysis is a complementary method to identify “novel” genes, small RNAs, regulatory regions, and operon structures, thus improving the structural annotation in bacteria. In particular, the identification of non-coding RNAs has revealed their widespread occurrence and functional importance in gene regulation, stress and virulence. However, very little is known about non-coding transcripts in Histophilus somni, one of the causative agents of Bovine Respiratory Disease (BRD) as well as bovine infertility, abortion, septicemia, arthritis, myocarditis, and thrombotic meningoencephalitis. In this study, we report a single nucleotide resolution transcriptome map of H. somni strain 2336 using RNA-Seq method. The RNA-Seq based transcriptome map identified 94 sRNAs in the H. somni genome of which 82 sRNAs were never predicted or reported in earlier studies. We also identified 38 novel potential protein coding open reading frames that were absent in the current genome annotation. The transcriptome map allowed the identification of 278 operon (total 730 genes) structures in the genome. When compared with the genome sequence of a non-virulent strain 129Pt, a disproportionate number of sRNAs (?30%) were located in genomic region unique to strain 2336 (?18% of the total genome). This observation suggests that a number of the newly identified sRNAs in strain 2336 may be involved in strain-specific adaptations. PMID:22276113

Kumar, Ranjit; Lawrence, Mark L.; Watt, James; Cooksey, Amanda M.; Burgess, Shane C.; Nanduri, Bindu

2012-01-01

71

REVIEW: ASSESSING THE POTENTIAL TO INDUCE RESPIRATORY HYPERSENSITIVITY  

EPA Science Inventory

The respiratory tract has been long recognized as an important target organ in the safety assessment of drugs and chemicals, as well as protein- or peptide-based products. Indeed, acute and repeat dose inhalation studies have been an important part of guideline studies throughou...

72

Biomarkers of Acute Respiratory Allergen Exposure: Screening For Sensitization Potential  

EPA Science Inventory

Rationale: An in vitro assay to identify respiratory sensitizers will provide a rapid screen and reduce animal use. The study goal was to identify biomarkers that differentiate allergen versus non-allergen responses following an acute exposure. Methods: Female BALB/c mice rec...

73

Control of pathogenic effector T-cell activities in situ by PD-L1 expression on respiratory inflammatory dendritic cells during respiratory syncytial virus infection.  

PubMed

Respiratory syncytial virus (RSV) infection is a leading cause of severe lower respiratory tract illness in young infants, the elderly and immunocompromised individuals. We demonstrate here that the co-inhibitory molecule programmed cell death 1 (PD-1) is selectively upregulated on T cells within the respiratory tract during both murine and human RSV infection. Importantly, the interaction of PD-1 with its ligand PD-L1 is vital to restrict the pro-inflammatory activities of lung effector T cells in situ, thereby inhibiting the development of excessive pulmonary inflammation and injury during RSV infection. We further identify that PD-L1 expression on lung inflammatory dendritic cells is critical to suppress inflammatory T-cell activities, and an interferon-STAT1-IRF1 axis is responsible for increased PD-L1 expression on lung inflammatory dendritic cells. Our findings suggest a potentially critical role of PD-L1 and PD-1 interactions in the lung for controlling host inflammatory responses and disease progression in clinical RSV infection.Mucosal Immunology advance online publication, 3 December 2014; doi:10.1038/mi.2014.106. PMID:25465101

Yao, S; Jiang, L; Moser, E K; Jewett, L B; Wright, J; Du, J; Zhou, B; Davis, S D; Krupp, N L; Braciale, T J; Sun, J

2014-12-01

74

Real-time electronic nose based pathogen detection for respiratory intensive care patients  

Microsoft Academic Search

An acoustic wave based electronic nose was used to monitor the exhaled breath of patients in an intensive care unit. The system could be used for detecting and identifying bacterial infections of the lungs and airways in real-time. The patients all had ventilator assisted breathing and were diagnosed with respiratory failure due to severe pneumonia and other extrapulmonary diseases by

Chung-Hung Shih; Yuh-Jiuan Lin; Kun-Feng Lee; Pei-Yu Chien; Philip Drake

2010-01-01

75

Pathogenicity and Molecular Characterization of Emerging Porcine Reproductive and Respiratory Syndrome Virus in Vietnam in 2007  

Technology Transfer Automated Retrieval System (TEKTRAN)

In 2007, Vietnam experienced swine disease outbreaks causing clinical signs similar to the "porcine high fever disease" that occurred in China during 2006. Analysis of diagnostic samples from the disease outbreaks in Vietnam identified porcine reproductive and respiratory syndrome virus (PRRSV) and ...

76

Highly pathogenic porcine reproductive and respiratory syndrome virus infection results in acute lung injury of the infected pigs.  

PubMed

Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) was firstly characterized in 2006 in China. The virus has caused great economic loss to the Chinese swine production during the past years. Herein, we experimentally infected SPF pigs using two strains of PRRSV with different pathogenicity and observed the lung pathological changes looking for new sights on the possible pathogenesis associated with the virulence of HP-PRRSV. The results indicated that the HP-PRRSV-infected pigs died and exhibited severe pathological changes of lungs featuring increased neutrophils, mast cells and mononuclear macrophages, compared with the pigs inoculated with low pathogenic (LP-) PRRSV. Furthermore, the pigs infected with HP-PRRSV showed the higher levels of tumor necrosis factor (TNF)-?, interleukin (IL)-1?, interleukin (IL)-8 and histamine, leukotriene B4 (LTB4), platelet activation factor (PAF) in sera than those inoculated with LP-PRRSV. Additionally, the fibrosis of lung was observed in the HP-PRRSV-infected pigs. At present, our findings suggest that the aberrant immune responses triggered by HP-PRRSV infection are closely related to acute lung injury (ALI), and especially the pathological changes in lung vascular system are of particular significance. These associated pathological changes of lung are in part responsible for the additional morbidity and mortality observed in HP-PRRSV infection. PMID:24472226

Han, Deping; Hu, Yanxin; Li, Limin; Tian, Haiyan; Chen, Zhi; Wang, Lin; Ma, Haiyan; Yang, Hanchun; Teng, Kedao

2014-03-14

77

Molecular Characterization of Transcriptome-wide Interactions between Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus and Porcine Alveolar Macrophages in vivo  

PubMed Central

Porcine reproductive and respiratory syndrome virus (PRRSV) infects mainly the porcine alveolar macrophages (PAMs) and causes porcine reproductive and respiratory syndrome (PRRS). Previous studies have analyzed the global gene expression profiles of lung tissue in vivo and PAMs in vitro following infection with PRRSV, however, transcriptome-wide understanding of the interaction between highly pathogenic PRRSV (HP-PRRSV) and PAMs in vivo has not yet been established. In this study, we employed Affymetrix microarrays to investigate the gene expression patterns of PAMs isolated from Tongcheng piglets (a Chinese indigenous breed) after infection with HP-PRRSV. During the infection, Tongcheng piglets exhibited typical clinical signs, e.g. fever, asthma, coughing, anorexia, lethargy and convulsion, but displayed mild regional lung damage at 5 and 7 dpi. Microarray analysis revealed that HP-PRRSV infection has affected PAMs in expression of the important genes involved in cytoskeleton and exocytosis organization, protein degradation and folding, intracellular calcium and zinc homeostasis. Several potential antiviral strategies might be employed in PAMs, including upregulating IFN-induced genes and increasing intracellular zinc ion concentration. And inhibition of the complement system likely attenuated the lung damage during HP-PRRSV infection. Transcriptomic analysis of PAMs in vivo could lead to a better understanding of the HP-PRRSV-host interaction, and to the identification of novel antiviral therapies and genetic components of swine tolerance/susceptibility to HP-PRRS. PMID:21850204

Zhou, Ping; Zhai, Shanli; Zhou, Xiang; Lin, Ping; Jiang, Tengfei; Hu, Xueying; Jiang, Yunbo; Wu, Bin; Zhang, Qingde; Xu, Xuewen; Li, Jin-ping; Liu, Bang

2011-01-01

78

Endobiotic bacteria and their pathogenic potential in cnidarian tentacles  

NASA Astrophysics Data System (ADS)

Endobiotic bacteria colonize the tentacles of cnidaria. This paper provides first insight into the bacterial spectrum and its potential of pathogenic activities inside four cnidarian species. Sample material originating from Scottish waters comprises the jellyfish species Cyanea capillata and C. lamarckii, hydrozoa Tubularia indivisa and sea anemone Sagartia elegans. Mixed cultures of endobiotic bacteria, pure cultures selected on basis of haemolysis, but also lyophilized samples were prepared from tentacles and used for DGGE-profiling with subsequent phylogenetic analysis of 16S rDNA fragments. Bacteria were detected in each of the cnidarian species tested. Twenty-one bacterial species including four groups of closely related organisms were found in culture material. The species within these groups could not be differentiated from each other (one group of Pseudoalteromonas spp., two groups of Shewanella spp., one group of Vibrio spp.). Each of the hosts exhibits a specific endobacterial spectrum. Solely Cyanea lamarckii harboured Moritella viscosa. Only in Cyanea capillata, members of the Shewanella group #2 and the species Pseudoalteromonas arctica, Shewanella violacea, Sulfitobacter pontiacus and Arcobacter butzleri were detected. Hydrozoa Tubularia indivisa provided an amazingly wide spectrum of nine bacterial species. Exclusively, in the sea anemone Sagartia elegans, the bacterial species P. aliena was found. Overall eleven bacterial species detected were described recently as novel species. Four 16S rDNA fragments generated from lyophilized material displayed extremely low relationship to their next neighbours. These organisms are regarded as members of the endobiotic “terra incognita”. Since the origin of cnidarian toxins is unclear, the possible pathogenic activity of endobiotic bacteria has to be taken into account. Literature data show that their next neighbours display an interesting diversity of haemolytic, septicaemic and necrotic actions including the production of cytotoxins, tetrodotoxin and R-toxin. Findings of haemolysis tests support the literature data. The potential producers are Endozoicimonas elysicola, Moritella viscosa, Photobacterium profundum, P. aliena, P. tetraodonis, Shewanella waksmanii, Vibrio splendidus, V. aestuarius, Arcobacter butzleri.

Schuett, Christian; Doepke, Hilke

2010-09-01

79

FilmArray, an Automated Nested Multiplex PCR System for Multi-Pathogen Detection: Development and Application to Respiratory Tract Infection  

PubMed Central

The ideal clinical diagnostic system should deliver rapid, sensitive, specific and reproducible results while minimizing the requirements for specialized laboratory facilities and skilled technicians. We describe an integrated diagnostic platform, the “FilmArray”, which fully automates the detection and identification of multiple organisms from a single sample in about one hour. An unprocessed biologic/clinical sample is subjected to nucleic acid purification, reverse transcription, a high-order nested multiplex polymerase chain reaction and amplicon melt curve analysis. Biochemical reactions are enclosed in a disposable pouch, minimizing the PCR contamination risk. FilmArray has the potential to detect greater than 100 different nucleic acid targets at one time. These features make the system well-suited for molecular detection of infectious agents. Validation of the FilmArray technology was achieved through development of a panel of assays capable of identifying 21 common viral and bacterial respiratory pathogens. Initial testing of the system using both cultured organisms and clinical nasal aspirates obtained from children demonstrated an analytical and clinical sensitivity and specificity comparable to existing diagnostic platforms. We demonstrate that automated identification of pathogens from their corresponding target amplicon(s) can be accomplished by analysis of the DNA melting curve of the amplicon. PMID:22039434

Poritz, Mark A.; Blaschke, Anne J.; Byington, Carrie L.; Meyers, Lindsay; Nilsson, Kody; Jones, David E.; Thatcher, Stephanie A.; Robbins, Thomas; Lingenfelter, Beth; Amiott, Elizabeth; Herbener, Amy; Daly, Judy; Dobrowolski, Steven F.; Teng, David H. -F.; Ririe, Kirk M.

2011-01-01

80

Respiratory virus is a real pathogen in immunocompetent community-acquired pneumonia: comparing to influenza like illness and volunteer controls  

PubMed Central

Background Viral pathogens were more commonly reported than previously estimated in community-acquired pneumonia (CAP) patients. However, the real role of virus was still controversial. Methods Consecutive adult patients with CAP between April and December, 2009 were prospectively enrolled. A four-fold or greater increase of IgG-titres against respiratory viruses in pair sera was tested by means of hemagglutination inhibition assay or indirect immunofluorescence. Swab samples were tested by cell culture and/or nucleic amplification tests. Viral etiology was considered definitive if at least one of the above tests was positive. Results Viral etiology was established in fifty-two (34.9%) of 149 CAP patients, twenty-two (81.5%) of 27 influenza like illness patients, and none of 75 volunteer controls. Forty-seven CAP patients were infected by a single virus (24 influenza A virus, 5 influenza B, 10 parainfluenza virus type 3 [PIV-3], 2 PIV-1, 2 adenovirus, 2 human rhinovirus and 2 coronavirus OC43), five cases by two or three viruses co-infection. Fever???39°C (66.7%), fatigue (64.6%), and purulent sputum (52.1%) was the most common symptoms in viral pneumonia patients. On multivariate analysis, myalgia was included in the model for pneumonia associated with influenza infection. In the CURB-65 model only influenza infection was found independently associated with severe disease (CURB-65 score???3) out of variables, including age(years), sex, current smoking status, sick contact with febrile patients, numbers of comorbidity, presence of influenza infection, presence of PIV infection, with P?=?0.021, OR 7.86 (95% CI 1.37-45.04). Conclusion Respiratory virus was not a bystander, but pathogenic in pneumonia and was a common cause of CAP. PMID:25178477

2014-01-01

81

Antimicrobial susceptibility monitoring of respiratory tract pathogens isolated from diseased cattle and pigs across Europe: the VetPath study.  

PubMed

VetPath is an ongoing pan-European antibiotic susceptibility monitoring programme collecting pathogens from diseased antimicrobial non-treated cattle, pigs and poultry. In the current study, 1001 isolates from cattle and pig respiratory tract infections were tested for their antimicrobial susceptibilities. Non-replicate lung samples or nasopharyngeal/nasal swabs were collected from animals with acute clinical signs in 11 countries during 2002-2006. Pasteurella multocida and Mannheimia haemolytica from cattle and P. multocida, Actinobacillus pleuropneumoniae and Streptococcus suis from pigs were isolated by standard methods. S. suis was also isolated from meningitis cases. MICs of 16 antibiotics were assessed centrally by broth microdilution following CLSI recommendations. Results were interpreted using CLSI breakpoints where available. P. multocida (231) and M. haemolytica (138) isolates were all susceptible to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin and trimethoprim/sulfamethoxazole. Resistance to florfenicol and spectinomycin was 0.4% and 3.5% in P. multocida, respectively, and absent in M. haemolytica isolates. Tetracycline resistance was 5.7% and 14.6% for P. multocida and M. haemolytica. In pigs, 230 P. multocida, 220 A. pleuropneumoniae and 182 S. suis isolates were recovered. Resistance to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin, florfenicol, tiamulin and tilmicosin was absent or <1%. Trimethoprim/sulfamethoxazole resistance was 3-6% and tetracycline resistance varied from 14.7% in A. pleuropneumoniae to 81.8% in S. suis. In conclusion, low resistance to antibiotics with defined clinical breakpoints, except for tetracycline, was observed among the major respiratory tract pathogens recovered from cattle and pigs. Since for approximately half of the antibiotics in this panel no CLSI-defined breakpoints were available, setting of the missing veterinary breakpoints is important. PMID:24837878

de Jong, Anno; Thomas, Valérie; Simjee, Shabbir; Moyaert, Hilde; El Garch, Farid; Maher, Kirsty; Morrissey, Ian; Butty, Pascal; Klein, Ulrich; Marion, Hervé; Rigaut, Delphine; Vallé, Michel

2014-08-01

82

Identification of apoptotic cells in the thymus of piglets infected with highly pathogenic porcine reproductive and respiratory syndrome virus.  

PubMed

Porcine reproductive and respiratory syndrome (PRRS) is an immunosuppressive disease that is characterized by respiratory distress and poor growth in piglets and by severe reproductive failure in sows. PRRS was first recognized in the 1990s in Europe and the United States. In 2006, highly pathogenic (HP)-PRRS caused enormous economic losses in China. Our previous studies demonstrated that the HP-PRRS virus (HP-PRRSV) induced the apoptosis of numerous thymocytes in infected piglets, leading to severe thymus atrophy. To further identify the subset of apoptotic cells in thymus of HP-PRRSV-infected piglets, different cell types, apoptotic cells, and HP-PRRSV were marked with the corresponding markers. Results of the colocalization demonstrated that the apoptotic cells were not infected by HP-PRRSV, and most of them were CD3(+) T cells. No apoptosis was observed in the epithelial cells, and only few CD14(+) cells were apoptotic. HP-PRRSV was only found in CD14(+) cells, and epithelial cells and CD3(+) cells were not infected by HP-PRRSV. This is the first study to report the apoptotic and infected cells in the thymuses of HP-PRRSV-infected piglets. PMID:24787009

Li, Yuming; Wang, Gang; Liu, Yonggang; Tu, Yabin; He, Yuli; Wang, Zhiyan; Han, Zifeng; Li, Li; Li, Aidong; Tao, Ye; Cai, Xuehui

2014-08-30

83

Inhibitory activity of a standardized elderberry liquid extract against clinically-relevant human respiratory bacterial pathogens and influenza A and B viruses  

PubMed Central

Background Black elderberries (Sambucus nigra L.) are well known as supportive agents against common cold and influenza. It is further known that bacterial super-infection during an influenza virus (IV) infection can lead to severe pneumonia. We have analyzed a standardized elderberry extract (Rubini, BerryPharma AG) for its antimicrobial and antiviral activity using the microtitre broth micro-dilution assay against three Gram-positive bacteria and one Gram-negative bacteria responsible for infections of the upper respiratory tract, as well as cell culture experiments for two different strains of influenza virus. Methods The antimicrobial activity of the elderberry extract was determined by bacterial growth experiments in liquid cultures using the extract at concentrations of 5%, 10%, 15% and 20%. The inhibitory effects were determined by plating the bacteria on agar plates. In addition, the inhibitory potential of the extract on the propagation of human pathogenic H5N1-type influenza A virus isolated from a patient and an influenza B virus strain was investigated using MTT and focus assays. Results For the first time, it was shown that a standardized elderberry liquid extract possesses antimicrobial activity against both Gram-positive bacteria of Streptococcus pyogenes and group C and G Streptococci, and the Gram-negative bacterium Branhamella catarrhalis in liquid cultures. The liquid extract also displays an inhibitory effect on the propagation of human pathogenic influenza viruses. Conclusion Rubini elderberry liquid extract is active against human pathogenic bacteria as well as influenza viruses. The activities shown suggest that additional and alternative approaches to combat infections might be provided by this natural product. PMID:21352539

2011-01-01

84

Mutations that permit residual CFTR function delay acquisition of multiple respiratory pathogens in CF patients  

PubMed Central

Background Lung infection by various organisms is a characteristic feature of cystic fibrosis (CF). CFTR genotype effects acquisition of Pseudomonas aeruginosa (Pa), however the effect on acquisition of other infectious organisms that frequently precede Pa is relatively unknown. Understanding the role of CFTR in the acquisition of organisms first detected in patients may help guide symptomatic and molecular-based treatment for CF. Methods Lung infection, defined as a single positive respiratory tract culture, was assessed for 13 organisms in 1,381 individuals with CF. Subjects were divided by predicted CFTR function: 'Residual': carrying at least one partial function CFTR mutation (class IV or V) and 'Minimal' those who do not carry a partial function mutation. Kaplan-Meier estimates were created to assess CFTR effect on age of acquisition for each organism. Cox proportional hazard models were performed to control for possible cofactors. A separate Cox regression was used to determine whether defining infection with Pa, mucoid Pa or Aspergillus (Asp) using alternative criteria affected the results. The influence of severity of lung disease at the time of acquisition was evaluated using stratified Cox regression methods by lung disease categories. Results Subjects with 'Minimal' CFTR function had a higher hazard than patients with 'Residual' function for acquisition of 9 of 13 organisms studied (HR ranging from 1.7 to 3.78 based on the organism studied). Subjects with minimal CFTR function acquired infection at a younger age than those with residual function for 12 of 13 organisms (p-values ranging: < 0.001 to 0.017). Minimal CFTR function also associated with younger age of infection when 3 alternative definitions of infection with Pa, mucoid Pa or Asp were employed. Risk of infection is correlated with CFTR function for 8 of 9 organisms in patients with good lung function (>90%ile) but only 1 of 9 organisms in those with poorer lung function (<50%ile). Conclusions Residual CFTR function correlates with later onset of respiratory tract infection by a wide spectrum of organisms frequently cultured from CF patients. The protective effect conferred by residual CFTR function is diminished in CF patients with more advanced lung disease. PMID:20932301

2010-01-01

85

Pathogenic Potential of Saccharomyces Strains Isolated from Dietary Supplements  

PubMed Central

Saccharomyces cerevisiae plays a beneficial role in health because of its intrinsic nutritional value and bio-functional properties, which is why it is also used as a dietary supplement. However, the perception that S. cerevisiae is harmless has changed due to an increasing number of infections caused by this yeast. Given this scenario, we have tested whether viable strains contained in dietary supplements displayed virulence-associated phenotypic traits that could contribute to virulence in humans. We have also performed an in vivo study of the pathogenic potential of these strains using a murine model of systemic infection by intravenous inoculation. A total of 5 strains were isolated from 22 commercial products and tested. Results highlight one strain (D14) in terms of burden levels in brains and kidneys and ability to cause death, whereas the other two strains (D2 and D4) were considered of low virulence. Our results suggest a strong relationship between some of the virulence-associated phenotypic traits (ability to grow at 39°C and pseudohyphal growth) and the in vivo virulence in a mouse model of intravenous inoculation for isolates under study. The isolate displaying greatest virulence (D14) was evaluated in an experimental murine model of gastrointestinal infection with immunosuppression and disruption of mucosal integrity, which are common risk factors for developing infection in humans, and results were compared with an avirulent strain (D23). We showed that D14 was able to spread to mesenteric nodes and distant organs under these conditions. Given the widespread consumption of dietary supplements, we recommend only safe strains be used. PMID:24879417

Monteoliva, Lucía; Querol, Amparo; Molina, María; Fernández-Espinar, María T.

2014-01-01

86

Pathogenic potential of Saccharomyces strains isolated from dietary supplements.  

PubMed

Saccharomyces cerevisiae plays a beneficial role in health because of its intrinsic nutritional value and bio-functional properties, which is why it is also used as a dietary supplement. However, the perception that S. cerevisiae is harmless has changed due to an increasing number of infections caused by this yeast. Given this scenario, we have tested whether viable strains contained in dietary supplements displayed virulence-associated phenotypic traits that could contribute to virulence in humans. We have also performed an in vivo study of the pathogenic potential of these strains using a murine model of systemic infection by intravenous inoculation. A total of 5 strains were isolated from 22 commercial products and tested. Results highlight one strain (D14) in terms of burden levels in brains and kidneys and ability to cause death, whereas the other two strains (D2 and D4) were considered of low virulence. Our results suggest a strong relationship between some of the virulence-associated phenotypic traits (ability to grow at 39°C and pseudohyphal growth) and the in vivo virulence in a mouse model of intravenous inoculation for isolates under study. The isolate displaying greatest virulence (D14) was evaluated in an experimental murine model of gastrointestinal infection with immunosuppression and disruption of mucosal integrity, which are common risk factors for developing infection in humans, and results were compared with an avirulent strain (D23). We showed that D14 was able to spread to mesenteric nodes and distant organs under these conditions. Given the widespread consumption of dietary supplements, we recommend only safe strains be used. PMID:24879417

Llopis, Silvia; Hernández-Haro, Carolina; Monteoliva, Lucía; Querol, Amparo; Molina, María; Fernández-Espinar, María T

2014-01-01

87

Antibacterial and mutagenic activity of inhaled bronchodilators on the respiratory pathogen Haemophilus influenzae.  

PubMed

The U.K. prevalence of non-beta-lactamase-mediated resistance to ampicillin among Haemophilus influenzae reached 4% in 1986. The majority (70%) of isolates of this type come from sputa of patients with chronic obstructive airways disease. This study investigated whether bronchodilator drugs delivered directly to the respiratory tract have any antibacterial activity and/or play a role in promoting selection of organisms with this type of resistance. Antibacterial activity was detected in two out of six pharmaceutical preparations for nebulization examination but was entirely attributable to the preservative (benzalkonium chloride) in them. Exposure of ampicillin-susceptible H. influenzae (minimum inhibitory concentration 0.25 mg l-1) to concentrations of salbutamol, fenoterol and beclomethasone theoretically attainable in vivo resulted, after 48 h, in isolation of colonies with reduced susceptibility to ampicillin (minimum inhibitory concentration 1-4 mg l-1) but reversion to beta-lactam susceptibility occurred following serial subculture on chocolate agar. Organisms with stable reduced susceptibility to ampicillin were obtained when exposure to one of these three bronchodilators in broth was followed by serial subculture on agar containing the same preparations at equivalent concentrations and when the period of exposure to salbutamol at 100 mg l-1 in broth was extended to 5 days. The occurrence of these phenomena in vivo might be contributing to failures in treatment of exacerbations with ampicillin and to an increasing prevalence of beta-lactamase-negative, ampicillin-resistant H. influenzae. PMID:2236759

Powell, M; Majcherczyk, P A; Williams, J D

1990-07-01

88

Synergistic effects of sequential infection with highly pathogenic porcine reproductive and respiratory syndrome virus and porcine circovirus type 2  

PubMed Central

Background Porcine reproductive and respiratory syndrome virus (PRRSV) is the causative agent of porcine reproductive and respiratory syndrome (PRRS) and porcine circovirus type 2 (PCV2) is associated with postweaning multisystemic wasting syndrome (PMWS) in pigs. Coinfection with highly pathogenic PRRSV (HP-PRRSV) and PCV2 in the field has recently become extensive in some Asian countries. A synergistic pathogenicity between PRRSV and PCV2 infections has previously been reported. However, the consequences of the sequential infection of pigs with these two viruses are unknown. Methods Thirty 35-day-old piglets were randomly divided into six groups (n = 5 each): HP-PRRSV/PCV2 (group 1, inoculated with HP-PRRSV, then inoculated with PCV2 one week later), PCV2/HP-PRRSV (group 2, inoculated with PCV2, then inoculated with HP-PRRSV one week later), HP-PRRSV+PCV2 (group 3, inoculated with HP-PRRSV and PCV2 concurrently), HP-PRRSV (group 4, inoculated with HP-PRRSV), PCV2 (group 5, inoculated with PCV2), and the control (group 6, uninfected). This experiment lasted 28 days. Clinical symptoms and rectal temperatures were recorded each day after inoculation, body weight was recorded weekly, and serum samples were obtained for viral nucleic acid quantification and antibody titration. Variations in CD3+, CD4+ CD8–, CD3+, CD4–, and CD8+ cells, natural killer (NK) cells, and mononuclear cells were determined by flow cytometry. The serum concentrations of interferon ? (IFN-?), tumor necrosis factor ? (TNF-?), interleukin 10 (IL-10), and macrophage granulocyte-colony stimulating factor (GM-CSF) were determined. Pathological changes in different tissues from the experimentally infected pigs were recorded. Results The piglets in group 1 had the highest viral loads, the lowest antibody titers, the most-severe clinical signs, and the highest mortality (3/5, 60%; the mortality in the other groups was 0%), and interstitial pneumonia was more severe in this group compare to the other HP-PRRSV infected groups. The serum levels of IFN-?, TNF-?, IL-10, and GM-CSF varied (increased or decreased) most widely in group 1, as did each immunocyte subgroup. Conclusions HP-PRRSV infection followed by PCV2 infection enhanced the replication of both viruses in the experimental piglets and led to more-severe clinical signs and lesions, indicating greater synergistic effects during the sequential infection of piglets with HP-PRRSV and then PCV2. PMID:23971711

2013-01-01

89

Transcription analysis on response of porcine alveolar macrophages to co-infection of the highly pathogenic porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae.  

PubMed

Porcine respiratory disease complex (PRDC) is of great concern economically, for swine producers worldwide. Co-infections with porcine reproductive and respiratory syndrome virus (PRRSV) and Mycoplasma hyopneumoniae (Mhp) are considered the major causative agents of PRDC, and responsible for mass mortality in pigs. Nevertheless, the molecular mechanisms underlying the host factors involved in pathogenesis and persistent infection have not been clearly established because of a lack of information regarding host responses following co-infection. In the current study, high throughput cDNA microarray assays were employed to evaluate host responses of porcine alveolar macrophages (PAM) to co-infection with highly pathogenic PRRSV (HP-PRRSV) and Mhp. A total of 2152 and 1760 genes were identified as being differentially expressed between the control group and PRRSV+Mhp co-infected group at 6 and 15h post infection, respectively. The DE genes were involved in many vital functional classes, including inflammatory response, immune response, apoptosis, defense response, signal transduction. The pathway analysis demonstrated that the most significant pathways were associated with chemokine signaling pathway, cytokine, TLR, RLR and NLR signaling pathways and Jak-STAT signaling pathway. STRING analysis demonstrated that IL-1? is an integral gene in co-infections with PRRSV and Mhp. The present study is the first to document the response of PAMs to co-infection with HP-PRRSV and Mhp. The observed gene expression profile could help with the screening of potential host agents for reducing the prevalence of co-infections, and to further develop our understanding of the molecular pathogenesis associated with PRRSV and Mhp co-infection in pigs. PMID:25445346

Li, Bin; Du, Luping; Xu, Xiangwei; Sun, Bing; Yu, Zhengyu; Feng, Zhixin; Liu, Maojun; Wei, Yanna; Wang, Haiyan; Shao, Guoqing; He, Kongwang

2015-01-22

90

Import risk assessment incorporating a dose-response model: introduction of highly pathogenic porcine reproductive and respiratory syndrome into Australia via illegally imported raw pork.  

PubMed

Highly pathogenic porcine reproductive and respiratory syndrome (PRRS) has spread through parts of south-east Asia, posing a risk to Australia. The objective of this study was to assess the probability of infection of a feral or domestic pig in Australia with highly pathogenic PRRS following ingestion of illegally imported raw pork. A conservative scenario was considered in which 500 g of raw pork was imported from the Philippines into Australia without being detected by border security, then discarded from a household and potentially accessed by a pig. Monte Carlo simulation of a two-dimensional, stochastic model was used to estimate the probability of entry and exposure, and the probability of infection was assessed by incorporating a virus-decay and mechanistic dose-response model. Results indicated that the probability of infection of a feral pig after ingestion of raw meat was higher than the probability of infection of a domestic pig. Sensitivity analysis was used to assess the influence of input parameters on model output probability estimates, and extension of the virus-decay and dose-response model was used to explore the impact of different temperatures and time from slaughter to ingestion of the meat, different weights of meat, and the level of viraemia at slaughter on the infectivity of meat. Parameters with the highest influence on the model output were the level of viraemia of a pig prior to slaughter and the probability of access by a feral pig to food-waste discarded on property surrounding a household. Extension of the decay and dose-response model showed that small pieces of meat (10 g) from a highly pathogenic PRRS viraemic pig could contain enough virus to have a high probability of infection of a pig, and that routes to Australia by sea or air from all highly pathogenic PRRS virus endemic countries were of interest dependent on the temperature of the raw meat during transport. This study highlighted the importance of mitigation strategies such as disposal of food-waste from international traffic as quarantine waste, and the need for further research into the probability of access to food-waste on properties by feral pigs. PMID:24502944

Brookes, V J; Hernández-Jover, M; Holyoake, P; Ward, M P

2014-03-01

91

Telomere components as potential therapeutic targets for treating microbial pathogen infections  

PubMed Central

In a number of microbial pathogens that undergoes antigenic variation to evade the host’s immune attack, genes encoding surface antigens are located at subtelomeric loci, and recent studies have revealed that telomere components play important roles in regulation of surface antigen expression in several of these pathogens, indicating that telomeres play critical roles in microbial pathogen virulence regulation. Importantly, although telomere protein components and their functions are largely conserved from protozoa to mammals, telomere protein homologs in microbial pathogens and humans have low sequence homology. Therefore, pathogen telomere components are potential drug targets for therapeutic approaches because first, most telomere proteins are essential for pathogens’ survival, and second, disruption of pathogens’ antigenic variation mechanism would facilitate host’s immune system to clear the infection. PMID:23125966

Li, Bibo

2012-01-01

92

CYTOKINE MRNA PROFILES FOR ISOCYANATES WITH KNOWN AND UNKNOWN POTENTIAL TO INDUCE RESPIRATORY SENSITIZATION  

EPA Science Inventory

Cytokine mRNA Profiles for Isocyanates with Known and Unknown Potential to Induce Respiratory Sensitization. Plitnick, L.M., Loveless, S.E., Ladics, G.S., Holsapple, M.P., Smialowicz, R.J., Woolhiser, M.R., Anderson, P.K., Smith, C., Sailstad, D.M. and Selgrade, M.J.K (2002) Tox...

93

CURRENT STATE OF PREDICTING THE RESPIRATORY ALLERGY POTENTIAL OF CHEMICALS: WHAT ARE THE ISSUES?  

EPA Science Inventory

Current State of Predicting the Respiratory Allergy Potential of Chemicals: What Are the Issues? M I. Gilmour1 and S. E. Loveless2, 1USEPA, Research Triangle Park, NC and 2DuPont Haskell Laboratory, Newark, DE. Many chemicals are clearly capable of eliciting immune respon...

94

WORKSHOP ON STATUS OF TEST METHODS FOR ASSESSING POTENTIAL OF CHEMICALS TO INDUCE RESPIRATORY ALLERGIC REACTIONS  

EPA Science Inventory

Because of the association between allergy and asthma and the increasing incidence of morbidity and mortality due to asthma, there is growing concern over the potential of industrial chemicals to produce allergic reactions in the respiratory tract. Two classes of chemicals have b...

95

Antibody-Based Sensors: Principles, Problems and Potential for Detection of Pathogens and Associated Toxins  

PubMed Central

Antibody-based sensors permit the rapid and sensitive analysis of a range of pathogens and associated toxins. A critical assessment of the implementation of such formats is provided, with reference to their principles, problems and potential for ‘on-site’ analysis. Particular emphasis is placed on the detection of foodborne bacterial pathogens, such as Escherichia coli and Listeria monocytogenes, and additional examples relating to the monitoring of fungal pathogens, viruses, mycotoxins, marine toxins and parasites are also provided. PMID:22408533

Byrne, Barry; Stack, Edwina; Gilmartin, Niamh; O'Kennedy, Richard

2009-01-01

96

Emergence of highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRS) in medium-scale swine farms in southeastern Cambodia.  

PubMed

Since 2006, reports from China and Viet Nam have alerted of an emergent highly pathogenic variant of porcine reproductive and respiratory syndrome virus (HP-PRRSV) in that region. The frequent occurrence of outbreaks in these countries puts Cambodian pig farms at high risk of infection, but no study had been conducted to investigate the presence of HP-PRRS in Cambodian farms. We investigated the presence of HP-PRRS in medium-scale (semi-commercial) swine farms in the Cambodian southeastern region. Specifically, one province bordering Viet Nam (Takeo) was selected due to the concentration of most semi-commercial farms in that province. A cross-sectional study was carried out, between July and September 2010 to assess whether the prevalence of infection in these farms was indicative of recent spread of PPRSV and to identify risk factors for infection. The number of farms to be sampled was established using methods for Lot Quality Assurance Surveys (LQAS), in order to achieve a pre-established ability to discriminate between two different prevalence settings. The target population comprised all semi-commercial farms in Takeo province from which a random sample of 35 farms was selected. Selected farms were visited and questionnaires administered to gather information on farm characteristics and husbandry practices. Blood samples from individual pigs were collected in each of the study farms and tested for PRRSV, along with a number of other swine respiratory pathogens in order to investigate potential interactions. Our results showed that the virus was already present in Takeo semi-commercial pig population (LQAS herd prevalence ?85%) at the time of sampling. The presence of sows in the farm and farm density were significantly associated (P<0.05) with the introduction and the presence of PRRS - but this was an unadjusted association as small sample size precluded multivariate analysis. Spatiotemporal description of the supposed pattern of infection revealed that the 1st farms infected were closely located to major national and provincial roads, connecting the Cambodian capital Phnom Penh to Viet Nam. PMID:25179789

Tornimbene, B; Frossard, J-P; Chhim, V; Sorn, S; Guitian, J; Drew, T W

2015-01-01

97

The broadly conserved regulator PhoP links pathogen virulence and membrane potential in Escherichia coli  

PubMed Central

Summary PhoP is considered a virulence regulator despite being conserved in both pathogenic and non-pathogenic Enterobacteriaceae. While Escherichia coli strains represent non-pathogenic commensal isolates and numerous virulent pathotypes, the PhoP virulence regulator has only been studied in commensal E. coli. To better understand how conserved transcription factors contribute to virulence, we characterized PhoP in pathogenic E. coli. Deletion of phoP significantly attenuated E. coli during extraintestinal infection. This was not surprising since we demonstrated that PhoP differentially regulated the transcription of >600 genes. In addition to survival at acidic pH and resistance to polymyxin, PhoP was required for repression of motility and oxygen-independent changes in the expression of primary dehydrogenase and terminal reductase respiratory chain components. All phenotypes have in common a reliance on an energized membrane. Thus, we hypothesized that PhoP mediates these effects by regulating genes encoding proteins that generate proton motive force. Indeed, bacteria lacking PhoP exhibited a hyper-polarized membrane and dissipation of the transmembrane electrochemical gradient increased susceptibility of the phoP mutant to acidic pH, while inhibiting respiratory generation of the proton gradient restored resistance to antimicrobial peptides independent of lipopolysaccharide modification. These findings demonstrate a connection between PhoP, virulence, and the energized state of the membrane. PMID:21854465

Alteri, Christopher J.; Lindner, Jonathon R.; Reiss, Daniel J.; Smith, Sara N.; Mobley, Harry L.T.

2011-01-01

98

Genome Sequences of Vibrio navarrensis, a Potential Human Pathogen  

PubMed Central

Vibrio navarrensis is an aquatic bacterium recently shown to be associated with human illness. We report the first genome sequences of three V. navarrensis strains obtained from clinical and environmental sources. Preliminary analyses of the sequences reveal that V. navarrensis contains genes commonly associated with virulence in other human pathogens. PMID:25414502

Gladney, Lori M.; Katz, Lee S.; Knipe, Kristen M.; Rowe, Lori A.; Conley, Andrew B.; Rishishwar, Lavanya; Mariño-Ramírez, Leonardo

2014-01-01

99

Pathogens in sludge: occurrence, inactivation, and potential for regrowth  

SciTech Connect

The USEPA has set forth regulations specifying the processes for pathogen control which are acceptable for both restricted and unrestricted use of sewage sludge. For unrestricted use, processes which disinfect sludge - eliminate its ability to cause infection - are required. However, there is still concern about the public health risks of unrestricted sludge use, principally because under favorable conditions, certain patho- gens can regrow in disinfected sludge. A careful examination of pathogen behavior in sludge was undertaken. It revealed that the only bacterial pathogens likely to regrow are associated with gastroenteritis, rather than more serious diseases, and that ingestion of a large number of these baceria would be required to cause illness in healthy individuals. A fungal health hazard is posed by Aspergillus fumigatis. It is already widely distributed in the environment, but is a hazard only to infants, the elderly, and those whose health is compromised. The authors conclude that the unrestricted use of disinfected sludge poses at most a modest health hazard, much less serious than than the use of non-disinfected sludge. Further steps are discussed which can be taken to prevent or control regrowth of those few pathogens which may pose a problem. 91 references, 6 tables.

Ward, R.L.; McFeters, G.A.; Yeager, J.G.

1984-07-01

100

Re-emerging of porcine respiratory and reproductive syndrome virus (lineage 3) and increased pathogenicity after genomic recombination with vaccine variant.  

PubMed

Porcine reproductive and respiratory syndrome virus (PRRSV) was first reported in China since late 1995 and several variants were further reported in subsequence years, causing huge economic losses to the Chinese swine industry. To date, three major lineages (lineage 3, 5.1 and 8.7) of Type 2 PRRSV were reported in China based on our global genotyping. The present study provides the epidemiology of the PRRSV in South China based on the isolates collected during 2009-2012, indicating three lineages (lineage 3, 5.1 and 8.7) of Type 2 PRRSV were still circulating in this area. Our phylogenetic reconstruction indicated that lineage 3 re-emerged in 2010 formed a huge cluster with closely related to the 2004 isolates from Hong Kong. Furthermore, the inter-lineage genomic recombination between MLV vaccine strain (lineage 5) and a recently re-emerged lineage 3 virus (QYYZ) has also been found in a farm practicing MLV vaccination. Our in vivo experiment comparing the pathogenicity and clinical presentations among currently isolated viruses indicated that pigs infected with recombinant lineage 3 virus (GM2) showed persistent higher fever compared to pigs infected by its wild counterpart (QYYZ). This study enhanced our understanding on potential importance of the recombination of PRRSV along with their evolution. PMID:25529828

Lu, Wen Hui; Tun, Hein Min; Sun, Bao Li; Mo, JianYui; Zhou, Qing Feng; Deng, Yu Xiu; Xie, Qing Mei; Bi, Ying Zuo; Leung, Frederick Chi-Ching; Ma, Jing Yun

2015-02-25

101

Evaluation of fast-track diagnostics and TaqMan array card real-time PCR assays for the detection of respiratory pathogens.  

PubMed

Several commercial assays are now available to detect the nucleic acid of multiple respiratory pathogens from a single specimen. Head-to-head comparisons of such assays using a single set of standard specimens provide additional information about key assay parameters such as sensitivity, specificity and lower limits of detection, and help to inform the decision regarding which method to use. We evaluated two real-time PCR platforms: the Fast-track Diagnostics® (FTD) multiplex respiratory panel and a TaqMan array card (TAC) for simultaneous uniplex detection of multiple respiratory pathogens. Two sets of samples were used to evaluate the assays. One set was created by spiking pooled nasal wash or phosphate buffered saline with specified volumes of known concentrations of virus and/or bacteria. Clinical nasal wash specimens from children with lower respiratory tract illness comprised the other set. Thirteen pathogen targets were compared between the two platforms. Testing with a validation panel of spiked samples revealed a sensitivity of 96.1% and 92.9% for the FTD and TAC assays, respectively. Specificity could not be reliably calculated due to a suspected contamination of the sample substrate. Inter-assay agreement was high (> 95%) for most targets. Previously untested clinical specimens tested by both assays revealed a high percent agreement (> 95%) for all except rhinovirus, enterovirus and Streptococcus pneumoniae. Limitations of this evaluation included extraction of the validation samples by two different methods and the evaluation of the assays in different laboratories. However, neither of these factors significantly impacted inter-assay agreement for these sets of samples, and it was demonstrated that both assays could reliably detect clinically relevant concentrations of bacterial and viral pathogens. PMID:25448378

Driscoll, Amanda J; Karron, Ruth A; Bhat, Niranjan; Thumar, Bhagvanji; Kodani, Maja; Fields, Barry S; Whitney, Cynthia G; Levine, Orin S; O'Brien, Katherine L; Murdoch, David R

2014-12-01

102

First Complete Genome Sequence of Escherichia albertii Strain KF1, a New Potential Human Enteric Pathogen  

PubMed Central

Escherichia albertii has been recently recognized as an emerging human and bird enteric pathogen. Here, we report the first complete chromosome nucleotide sequence of a clinical isolate of E. albertii strain KF1, which may provide information about the pathogenic potential of this new species and the mechanisms of evolution of enteropathogenic Escherichia spp. PMID:24482506

Daniluk, Tamara; Swiecicka, Izabela; Murawska, Emilia; Sciepuk, Malgorzata; Leszczynska, Katarzyna

2014-01-01

103

First Complete Genome Sequence of Escherichia albertii Strain KF1, a New Potential Human Enteric Pathogen.  

PubMed

Escherichia albertii has been recently recognized as an emerging human and bird enteric pathogen. Here, we report the first complete chromosome nucleotide sequence of a clinical isolate of E. albertii strain KF1, which may provide information about the pathogenic potential of this new species and the mechanisms of evolution of enteropathogenic Escherichia spp. PMID:24482506

Fiedoruk, Krzysztof; Daniluk, Tamara; Swiecicka, Izabela; Murawska, Emilia; Sciepuk, Malgorzata; Leszczynska, Katarzyna

2014-01-01

104

Comparison between acute oral/respiratory and chronic stomatitis/gingivitis isolates of feline calicivirus: pathogenicity, antigenic profile and cross-neutralisation studies.  

PubMed

Feline calicivirus (FCV) is a major oral and respiratory pathogen of cats, able to induce subclinical infection as well as acute disease. It is also characterized by a high degree of antigenic variation. This work sought to address the question of the existence of distinct biotypes of FCV. Eight French, 6 British and 9 American FCV isolates, responsible for acute oral/respiratory disease or chronic gingivitis/stomatitis, were compared for their pathogenicity, antigenic profiles and serological relationships. Antigenic profiles were assessed by an indirect immunofluorescence assay with a large panel of characterized monoclonal antibodies. Cross-neutralisation assays were performed with specific cat antisera collected at 30 days p.i., then analysed by calculation of antigenic bilateral relatedness and dominance. Whatever their pathogenic origin, all the isolates induced an acute upper-respiratory tract infection in oronasally infected SPF kittens. Their antigenic profiles were different and did not correlate with their geographical or pathological origin. Cross-neutralisation studies and calculation of the mean bilateral relatedness allowed us to distinguish chronic original isolates from acute original ones. This study did not confirm the existence of FCV biotypes but showed that the chronic carrier state is related to the emergence of antigenically distant viruses. PMID:10752551

Poulet, H; Brunet, S; Soulier, M; Leroy, V; Goutebroze, S; Chappuis, G

2000-01-01

105

Verified and potential pathogens of predatory mites (Acari: Phytoseiidae)  

Microsoft Academic Search

Several species of phytoseiid mites (Acari: Phytoseiidae), including species of the genera Amblyseius, Galendromus, Metaseiulus, Neoseiulus, Phytoseiulus and Typhlodromus, are currently reared for biological control of various crop pests and\\/or as model organisms for the study of predator–prey\\u000a interactions. Pathogen-free phytoseiid mites are important to obtain high efficacy in biological pest control and to get reliable\\u000a data in mite research,

Conny Schütte; Marcel Dicke

2008-01-01

106

Microbial studies of compost: bacterial identification, and their potential for turfgrass pathogen suppression  

E-print Network

Microbial studies of compost: bacterial identification, and their potential for turfgrass pathogen; accepted 17 April 2002 Keywords: Bacteria, compost, biocontrol disease suppression, grey snow mould Composting is the degradation of organic materials through the activities of diverse microorganisms

Boland, Greg J.

107

Cross-talk between lung and systemic circulation during carbon nanotube respiratory exposure. Potential biomarkers.  

PubMed

Nanotechnology is an emerging field that demands urgent development of adequate toxicology and risk assessment. The previous experimental data on carbon nanotube respiratory exposure strongly suggest the need for complex evaluation of potential toxicity. Our work demonstrates that after carbon nanotube deposition in the lung, acute local and systemic responses are activated and characterized by a blood gene and protein expression signature. The approach described here will foster the development of biomarkers for application in human screening of nanoparticle exposure. PMID:19049393

Erdely, Aaron; Hulderman, Tracy; Salmen, Rebecca; Liston, Angie; Zeidler-Erdely, Patti C; Schwegler-Berry, Diane; Castranova, Vincent; Koyama, Shozo; Kim, Yoong-Ahm; Endo, Morinobu; Simeonova, Petia P

2009-01-01

108

Potential human pathogenic bacteria in a mixed urban watershed as revealed by pyrosequencing.  

PubMed

Current microbial source tracking (MST) methods for water depend on testing for fecal indicator bacterial counts or specific marker gene sequences to identify fecal contamination where potential human pathogenic bacteria could be present. In this study, we applied 454 high-throughput pyrosequencing to identify bacterial pathogen DNA sequences, including those not traditionally monitored by MST and correlated their abundances to specific sources of contamination such as urban runoff and agricultural runoff from concentrated animal feeding operations (CAFOs), recreation park area, waste-water treatment plants, and natural sites with little or no human activities. Samples for pyrosequencing were surface water, and sediment collected from 19 sites. A total of 12,959 16S rRNA gene sequences with average length of ?400 bp were obtained, and were assigned to corresponding taxonomic ranks using ribosomal database project (RDP), Classifier and Greengenes databases. The percent of total potential pathogens were highest in urban runoff water (7.94%), agricultural runoff sediment (6.52%), and Prado Park sediment (6.00%), respectively. Although the numbers of DNA sequence tags from pyrosequencing were very high for the natural site, corresponding percent potential pathogens were very low (3.78-4.08%). Most of the potential pathogenic bacterial sequences identified were from three major phyla, namely, Proteobacteria, Bacteroidetes, and Firmicutes. The use of deep sequencing may provide improved and faster methods for the identification of pathogen sources in most watersheds so that better risk assessment methods may be developed to enhance public health. PMID:24278139

Ibekwe, A Mark; Leddy, Menu; Murinda, Shelton E

2013-01-01

109

Global human frequencies of predicted nuclear pathogenic variants and the role played by protein hydrophobicity in pathogenicity potential  

PubMed Central

Mitochondrial proteins are coded by nuclear (nDNA) and mitochondrial (mtDNA) genes, implying a complex cross-talk between the two genomes. Here we investigated the diversity displayed in 104 nuclear-coded mitochondrial proteins from 1,092 individuals from the 1000 Genomes dataset, in order to evaluate if these genes are under the effects of purifying selection and how that selection compares with their mitochondrial encoded counterparts. Only the very rare variants (frequency < 0.1%) in these nDNA genes are indistinguishable from a random set from all possible variants in terms of predicted pathogenicity score, but more frequent variants display distinct signs of purifying selection. Comparisons of selection strength indicate stronger selection in the mtDNA genes compared to this set of nDNA genes, accounted for by the high hydrophobicity of the proteins coded by the mtDNA. Most of the predicted pathogenic variants in the nDNA genes were restricted to a single continental population. The proportion of individuals having at least one potential pathogenic mutation in this gene set was significantly lower in Europeans than in Africans and Asians. This difference may reflect demographic asymmetries, since African and Asian populations experienced main expansions in middle Holocene, while in Europeans the main expansions occurred earlier in the post-glacial period. PMID:25412673

Pereira, Luísa; Soares, Pedro; Triska, Petr; Rito, Teresa; van der Waerden, Agnes; Li, Biao; Radivojac, Predrag; Samuels, David C.

2014-01-01

110

Serologic Survey for Pathogens Potentially Affecting Pronghorn (Antilocapra Americana) Fawn Recruitment in Arizona, USA  

Microsoft Academic Search

During the 1990s, pronghorn (An- tilocapra americana) populations declined in Arizona, USA. To investigate potential causes of decline, we collected blood samples from hunter-harvested male pronghorn from 2001 to 2003 on four Arizona sites. Sera were tested for antibody to parainfluenza virus type 3 (PI3), bovine viral diarrhea virus, infectious bovine rhinotracheitis virus, bovine respiratory syncy- tial virus, epizootic hemorrhagic

Shelli A. Dubay; Ted H. Noon; James C. deVos; Richard A. Ockenfels

111

Stem respiratory potential in six softwood and four hardwood tree species in the central cascades of Oregon.  

PubMed

Mature and old growth trees of varying sapwood thickness were compared with regard to stem respiration. An increment core-based, laboratory method under controlled temperature was used to measure tissue-level respiration (termed respiratory potential) of ten different tree species. Bark (dead outer and live inner combined), sapwood, and heartwood thickness measurements were used to predict sapwood volume from stem diameter (including bark) for four of the ten species. These predictions of sapwood volume were used to scale respiratory potential to the main-bole level (excluding all branches). On the core level, species that maintained narrow sapwood (8-16% of bole radius) such as Pseudotusga menziesii, Taxus brevifolia, and Thuja plicata, had sapwood respiratory potentials in the lower bole that were 50% higher (P<0.05) than species with wide sapwood (>16% of bole radius), such as Abies amabilis, Pinus monticola, and Tsuga heterophylla. This pattern was not observed for inner bark respiratory potential, or for sapwood respiratory potential within the crown. On the main-bole level, respiratory potential per unit volume was inversely correlated to the live bole volumetric fraction (inner bark plus sapwood divided by whole bole volume) (Adj. R(2)=0.6). Specifically, tree species with 18-20% of the main bole alive potentially respired 1.3-3 times more per unit live bole volume than species with over 40%, suggesting that the live bole was less metabolically active in tree species that maintained large volumes of sapwood. PMID:12844251

Pruyn, Michele L; Harmon, Mark E; Gartner, B L

2003-09-01

112

Assessment of the respiratory sensitization potential of proteins using an enhanced mouse intranasal test (MINT).  

PubMed

There remains a need for a simple and predictive animal model to identify potential respiratory sensitizers. The mouse intranasal test (MINT) was developed to assess the relative allergic potential of detergent enzymes, however, the experimental endpoints were limited to evaluation of antibody levels. The present study was designed to evaluate additional endpoints (serum and allergic antibody levels, pulmonary inflammation and airway hyperresponsiveness (AHR)) to determine their value in improving the predictive accuracy of the MINT. BDF1 mice were intranasally instilled on days 1, 3, 10, 17 and 24 with subtilisin, ovalbumin, betalactoglobulin, mouse serum albumin or keyhole limpet hemocyanin; challenged with aerosolized methacholine or the sensitizing protein on day 29 to assess AHR, and sacrificed on day 29 or 30. Under the conditions of this study, evaluation of AHR did not improve the predictive power of this experimental model. Allergic antibody responses and IgG isotype characterization proved to be the most sensitive and reliable indicators of the protein allergenic potential with BAL responses providing additional insight. These data highlight that the evaluation of the respiratory sensitization potential of proteins can be best informed when multiple parameters are evaluated and that further improvements and refinements of the assay are necessary. PMID:23747714

Krieger, S M; Boverhof, D R; Woolhiser, M R; Hotchkiss, J A

2013-09-01

113

Detection of multiple potentially pathogenic bacteria in Matang mangrove estuaries, Malaysia.  

PubMed

The deltaic estuarine system of the Matang Mangrove Forest Reserve of Malaysia is a site where several human settlements and brackish water aquaculture have been established. Here, we evaluated the level of fecal indicator bacteria (FIB) and the presence of potentially pathogenic bacteria in the surface water and sediments. Higher levels of FIB were detected at downstream sampling sites from the fishing village, indicating it as a possible source of anthropogenic pollution to the estuary. Enterococci levels in the estuarine sediments were higher than in the surface water, while total coliforms and E. coli in the estuarine sediments were not detected in all samples. Also, various types of potentially pathogenic bacteria, including Klebsiella pneumoniae, Serratia marcescens and Enterobacter cloacae were isolated. The results indicate that the Matang estuarine system is contaminated with various types of potential human bacterial pathogens which might pose a health risk to the public. PMID:24820641

Ghaderpour, Aziz; Mohd Nasori, Khairul Nazrin; Chew, Li Lee; Chong, Ving Ching; Thong, Kwai Lin; Chai, Lay Ching

2014-06-15

114

Evaluating the Pathogenic Potential of Environmental Escherichia coli by Using the Caenorhabditis elegans Infection Model  

PubMed Central

The detection and abundance of Escherichia coli in water is used to monitor and mandate the quality of drinking and recreational water. Distinguishing commensal waterborne E. coli isolates from those that cause diarrhea or extraintestinal disease in humans is important for quantifying human health risk. A DNA microarray was used to evaluate the distribution of virulence genes in 148 E. coli environmental isolates from a watershed in eastern Ontario, Canada, and in eight clinical isolates. Their pathogenic potential was evaluated with Caenorhabditis elegans, and the concordance between the bioassay result and the pathotype deduced by genotyping was explored. Isolates identified as potentially pathogenic on the basis of their complement of virulence genes were significantly more likely to be pathogenic to C. elegans than those determined to be potentially nonpathogenic. A number of isolates that were identified as nonpathogenic on the basis of genotyping were pathogenic in the infection assay, suggesting that genotyping did not capture all potentially pathogenic types. The detection of the adhesin-encoding genes sfaD, focA, and focG, which encode adhesins; of iroN2, which encodes a siderophore receptor; of pic, which encodes an autotransporter protein; and of b1432, which encodes a putative transposase, was significantly associated with pathogenicity in the infection assay. Overall, E. coli isolates predicted to be pathogenic on the basis of genotyping were indeed so in the C. elegans infection assay. Furthermore, the detection of C. elegans-infective environmental isolates predicted to be nonpathogenic on the basis of genotyping suggests that there are hitherto-unrecognized virulence factors or combinations thereof that are important in the establishment of infection. PMID:23377948

Merkx-Jacques, Alexandra; Coors, Anja; Brousseau, Roland; Masson, Luke; Mazza, Alberto; Tien, Yuan-Ching

2013-01-01

115

Diagnosis of Tuberculosis by Trained African Giant Pouched Rats and Confounding Impact of Pathogens and Microflora of the Respiratory Tract  

PubMed Central

Trained African giant-pouched rats (Cricetomys gambianus) can detect Mycobacterium tuberculosis and show potential for the diagnosis of tuberculosis (TB). However, rats' ability to discriminate between clinical sputum containing other Mycobacterium spp. and nonmycobacterial species of the respiratory tract is unknown. It is also unknown whether nonmycobacterial species produce odor similar to M. tuberculosis and thereby cause the detection of smear-negative sputum. Sputum samples from 289 subjects were analyzed by smear microscopy, culture, and rats. Mycobacterium spp. were isolated on Lowenstein-Jensen medium, and nonmycobacterial species were isolated on four different media. The odor from nonmycobacterial species from smear- and M. tuberculosis culture-negative sputa detected by ?2 rats (“rat positive”) was analyzed by gas chromatography-mass spectrometry and compared to the M. tuberculosis odor. Rats detected 45 of 56 confirmed cases of TB, 4 of 5 suspected cases of TB, and 63 of 228 TB-negative subjects (sensitivity, 80.4%; specificity, 72.4%; accuracy, 73.9%; positive predictive value, 41.7%; negative predictive value, 93.8%). A total of 37 (78.7%) of 47 mycobacterial isolates were M. tuberculosis complex, with 75.7% from rat-positive sputa. Ten isolates were nontuberculous mycobacteria, one was M. intracellulare, one was M. avium subsp. hominissuis, and eight were unidentified. Rat-positive sputa with Moraxella catarrhalis, Streptococcus pneumoniae, Staphylococcus spp., and Enterococcus spp. were associated with TB. Rhodococcus, Nocardia, Streptomyces, Staphylococcus, and Candida spp. from rat-positive sputa did not produce M. tuberculosis-specific volatiles (methyl nicotinate, methyl para-anisate, and ortho-phenylanisole). Prevalence of Mycobacterium-related Nocardia and Rhodococcus in smear-negative sputa did not equal that of smear-negative mycobacteria (44.7%), of which 28.6% were rat positive. These findings and the absence of M. tuberculosis-specific volatiles in nonmycobacterial species indicate that rats can be trained to specifically detect M. tuberculosis. PMID:22135255

Mgode, Georgies F.; Weetjens, Bart J.; Nawrath, Thorben; Cox, Christophe; Jubitana, Maureen; Machang'u, Robert S.; Cohen-Bacrie, Stéphan; Bedotto, Marielle; Drancourt, Michel; Schulz, Stefan

2012-01-01

116

Hepatitis B Precore Protein: Pathogenic Potential and Therapeutic Promise  

PubMed Central

Hepatitis B virus (HBV), a small and economically packaged double-stranded DNA virus, represents an enormous global health care burden. In spite of an effective vaccine, HBV is endemic in many countries. Chronic hepatitis B (CHB) results in the development of significant clinical outcomes such as liver disease and hepatocellular carcinoma (HCC), which are associated with high mortality rates. HBV is a non-cytopathic virus, with the host's immune response responsible for the associated liver damage. Indeed, HBV appears to be a master of manipulating and modulating the immune response to achieve persistent and chronic infection. The HBV precore protein or hepatitis B e antigen (HBeAg) is a key viral protein involved in these processes, for instance though the down-regulation of the innate immune response. The development of new therapies that target viral proteins, such as HBeAg, which regulates of the immune system, may offer a new wave of potential therapeutics to circumvent progression to CHB and liver disease. PMID:22869468

Locarnini, Stephen

2012-01-01

117

Investigation of potentially pathogenic Clostridium difficile contamination in household environs.  

PubMed

As Clostridium difficile spores are resistant to many household cleaning products, the potential for community household contamination is high. The purpose of this study was to assess the prevalence of toxigenic C. difficile from environmental sources from a large urban area. Three to 5 household items or environmental dust was collected from 30 houses in Houston, Texas. A total of 127 environmental samples were collected from shoe bottoms (n = 63), bathroom surfaces (n = 15), house floor dusts (n = 12), or other household surfaces (n = 37). Forty one of 127 samples (32.3%) grew C. difficile. All 41 isolates were positive for toxin A and B genes and no isolate was positive for binary toxin genes. Shoe bottom swab samples had the highest percent of positive samples (25/63; 39.7%) followed by bathroom/toilet surfaces (5/15; 33.3%), house floor dust (4/12; 33.3%), and other surface swabs (7/37; 18.9%). Strains were grouped into 25 different ribotypes, the most prevalent type was 001 (5 strains). In conclusion, a high rate of environmental contamination of C. difficile was observed from community households from a large urban area. PMID:24657158

Alam, M Jahangir; Anu, Ananna; Walk, Seth T; Garey, Kevin W

2014-06-01

118

Nasopharyngeal colonization by potentially pathogenic bacteria found in healthy semi-captive wild-born chimpanzees in Uganda.  

PubMed

Information on the chimpanzee nasopharygeal colonization in captive sanctuaries and in the wild is rare. This study was undertaken to establish the nasopharygeal colonization and potential bacterial pathogens in sanctuary chimpanzees as a basis for improving chimpanzee and employee health. Nasopharygeal colonization of 39 healthy chimpanzees were analyzed by microbiological cultivation method and polymerase chain reaction (PCR) targeting the bacterial 16S rRNA gene. We report four major phyla dominated by Proteobacteria (50%), Fermicutes (35.7%), Bacteriodes (7.1%), and Cynobacteria (7.1%) in healthy semi-captive chimpanzees. Further classification based on 7-base oligomers revealed the following genera: Streptococcus, Veillonella, Neisseria, Prevotella, Kingella and unclassified Cynobacteria, Actinobacillus, Bacteriodes and Pasteurellaceae. On microbiological cultivation we were able to identify and characterize some of the bacteria to species level as Klebsiella pneumonie and Pseudomonas aeruginosa being dominant bacteria with 54.7% and 50% colonization, respectively. Of these, Streptococcus, Neisseria, Klebsiella, and Haemophillus have representatives known to potentially cause severe respiratory disease. Our data present important information on chimpanzee nasopharygeal colonization as a guide to understanding disease processes and pharmaceutical therapies required for improving the health of chimpanzees. The results from this study will guide the processes to improve procedures for routine management of sanctuary chimpanzees and use it as a basis for evaluation of future reintroduction possibilities. PMID:24395648

Mugisha, Lawrence; Köndgen, Sophie; Kaddu-Mulindwa, Deogratias; Gaffikin, Lynne; Leendertz, Fabian H

2014-02-01

119

The 30-Amino-Acid Deletion in the Nsp2 of Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Emerging in China Is Not Related to Its Virulence?  

PubMed Central

During the past 2 years, an atypical clinical outbreak, caused by a highly pathogenic porcine reproductive and respiratory syndrome virus (PRRSV) with a unique 30-amino-acid deletion in its Nsp2-coding region, was pandemic in China. In this study, we generated four full-length infectious cDNA clones: a clone of the highly virulent PRRSV strain JXwn06 (pWSK-JXwn), a clone of the low-virulence PRRSV strain HB-1/3.9 (pWSK-HB-1/3.9), a chimeric clone in which the Nsp2 region containing the 30-amino-acid deletion was replaced by the corresponding region of the low-virulence PRRSV strain HB-1/3.9 (pWSK-JXwn-HB1nsp2), and a mutated HB-1/3.9 clone with the same deletion in Nsp2 as JXwn06 (pWSK-HB1-ND30). We also investigated the pathogenicities of the rescued viruses (designated RvJXwn, RvJXwn-HB1nsp2, RvHB-1/3.9, and RvHB1-ND30, respectively) in specific-pathogen-free piglets in order to determine the role of the 30-amino-acid deletion in the virulence of the highly pathogenic PRRSV. All the rescued viruses could replicate stably in MARC-145 cells. Our findings indicated that RvJXwn-HB1nsp2 retained high virulence for piglets, like RvJXwn and the parental virus JXwn06, although the survival time of piglets infected with RvJXwn-HB1nsp2 was obviously prolonged. RvHB1-ND30 exhibited low virulence for piglets, like RvHB-1/3.9 and the parental virus HB-1/3.9. Therefore, we conclude that the 30-amino-acid deletion is not related to the virulence of the highly pathogenic PRRSV emerging in China. PMID:19244318

Zhou, Lei; Zhang, Jialong; Zeng, Jingwen; Yin, Shuoyan; Li, Yanhua; Zheng, Linying; Guo, Xin; Ge, Xinna; Yang, Hanchun

2009-01-01

120

Screening for several potential pathogens in feral pigeons (Columba livia) in Madrid  

Microsoft Academic Search

BACKGROUND: Pathogens with the zoonotic potential to infect humans, such as Campylobacter jejuni, Campylobacter coli and Chlamydophila psittaci, can be found in feral pigeons (Columba livia). Given the high density of these birds in the public parks and gardens of most cities, they may pose a direct threat to public health. METHODS: A total of 118 pigeons were captured in

Belén Vázquez; Fernando Esperón; Elena Neves; Juan López; Carlos Ballesteros; María Jesús Muñoz

2010-01-01

121

Sensitivity of Escherichia albertii, a potential foodborne pathogen, to food preservation treatments  

Technology Transfer Automated Retrieval System (TEKTRAN)

Escherichia albertii is a potential foodborne pathogen because of its documented ability to cause diarrheal disease by producing attachment and effacement lesions. Its tolerance to food preservation treatments has not been investigated. Heat, acid, and pressure tolerance were determined for stationa...

122

The potential for early and rapid pathogen detection within poultry processing through hyperspectral microscopy  

Technology Transfer Automated Retrieval System (TEKTRAN)

The acquisition of hyperspectral microscopic images containing both spatial and spectral data has shown potential for the early and rapid optical classification of foodborne pathogens. A hyperspectral microscope with a metal halide light source and acousto-optical tunable filter (AOTF) collects 89 ...

123

Update on the pathogenic potential and treatment options for Blastocystis sp  

PubMed Central

Although Blastocystis is one of the most common enteric parasites, there is still much controversy surrounding the pathogenicity and potential treatment options for this parasite. In this review we look at the evidence supporting Blastocystis as an intestinal pathogen as shown by numerous case studies and several in vivo studies and the evidence against. We describe the chronic nature of some infections and show the role of Blastocystis in immunocompromised patients and the relationship between irritable bowel syndrome and Blastocystis infection. There have been several studies that have suggested that pathogenicity may be subtype related. Metronidazole is the most widely accepted treatment for Blastocystis but several cases of treatment failure and resistance have been described. Other treatment options which have been suggested include paromomycin and trimethroprim- sulfamethoxazole. PMID:24883113

2014-01-01

124

Occurrence of Potentially Human-Pathogenic Escherichia coli O103 in Norwegian Sheep  

PubMed Central

The investigation of an outbreak of hemorrhagic-uremic syndrome in Norway in 2006 indicated that the outbreak strain Escherichia coli O103:H25 could originate from sheep. A national survey of the Norwegian sheep population was performed, with the aim of identifying and describing a possible reservoir of potentially human-pathogenic E. coli O103, in particular of the H types 2 and 25. The investigation of fecal samples from 585 sheep flocks resulted in 1,222 E. coli O103 isolates that were analyzed for the presence of eae and stx genes, while a subset of 369 isolates was further examined for flagellar antigens (H typing), stx subtypes, bfpA, astA, and molecular typing by pulsed-field gel electrophoresis (PFGE). The total ovine E. coli O103 serogroup was genetically diverse by numbers of H types, virulotypes, and PFGE banding patterns identified, although a tendency of clustering toward serotypes was seen. The flocks positive for potentially human-pathogenic E. coli O103 were geographically widely distributed, and no association could be found with county or geographical region. The survey showed that eae-negative, stx-negative E. coli O103, probably nonpathogenic to humans, is very common in sheep, with 27.5% of flocks positive. Moreover, the study documented a low prevalence (0.7%) of potentially human-pathogenic Shiga toxin-producing E. coli O103:H2, while STEC O103:H25 was not detected. However, 3.1% and 5.8% of the flocks were positive for enteropathogenic E. coli O103 belonging to H types 2 and 25, respectively. These isolates are of concern as potential human pathogens by themselves but more importantly as possible precursors for human-pathogenic STEC. PMID:24077709

Sekse, Camilla; Sunde, Marianne; Hopp, Petter; Bruheim, Torkjel; Cudjoe, Kofitsyo Sewornu; Kvitle, Bjørg

2013-01-01

125

Genome-wide phylogenetic analysis of the pathogenic potential of Vibrio furnissii.  

PubMed

We recently reported the genome sequence of a free-living strain of Vibrio furnissii (NCTC 11218) harvested from an estuarine environment. V. furnissii is a widespread, free-living proteobacterium and emerging pathogen that can cause acute gastroenteritis in humans and lethal zoonoses in aquatic invertebrates, including farmed crustaceans and molluscs. Here we present the analyses to assess the potential pathogenic impact of V. furnissii. We compared the complete genome of V. furnissii with 8 other emerging and pathogenic Vibrio species. We selected and analyzed more deeply 10 genomic regions based upon unique or common features, and used 3 of these regions to construct a phylogenetic tree. Thus, we positioned V. furnissii more accurately than before and revealed a closer relationship between V. furnissii and V. cholerae than previously thought. However, V. furnissii lacks several important features normally associated with virulence in the human pathogens V. cholera and V. vulnificus. A striking feature of the V. furnissii genome is the hugely increased Super Integron, compared to the other Vibrio. Analyses of predicted genomic islands resulted in the discovery of a protein sequence that is present only in Vibrio associated with diseases in aquatic animals. We also discovered evidence of high levels horizontal gene transfer in V. furnissii. V. furnissii seems therefore to have a dynamic and fluid genome that could quickly adapt to environmental perturbation or increase its pathogenicity. Taken together, these analyses confirm the potential of V. furnissii as an emerging marine and possible human pathogen, especially in the developing, tropical, coastal regions that are most at risk from climate change. PMID:25191313

Lux, Thomas M; Lee, Rob; Love, John

2014-01-01

126

Bacteria associated with crabs from cold waters with emphasis on the occurrence of potential human pathogens.  

PubMed Central

A diverse array of bacterial species, including several potential human pathogens, was isolated from edible crabs collected in cold waters. Crabs collected near Kodiak Island, Alaska, contained higher levels of bacteria than crabs collected away from regions of human habitation. The bacteria associated with the crabs collected near Kodiak included Yersinia enterocolitica, Klebsiella pneumoniae, and coagulase-negative Staphylococcus species; the pathogenicity of these isolates was demonstrated in mice. Although coliforms were not found, the bacterial species associated with the tissues of crabs collected near Kodiak indicate possible fecal contamination that may have occurred through contact with sewage. Compared with surrounding waters and sediments, the crab tissues contained much higher proportions of gram-positive cocci. As revealed by indirect plate counts and direct scanning electron microscopic observations, muscle and hemolymph tissues contained much lower levels of bacteria than shell and gill tissues. After the death of a crab, however, the numbers of bacteria associated with hemolymph and muscle tissues increased significantly. Microcosm studies showed that certain bacterial populations, e.g., Vibrio cholerae, can be bioaccumulated in crab gill tissues. The results of this study indicate the need for careful review of waste disposal practices where edible crabs may be contaminated with microorganisms that are potential human pathogens and the need for surveillance of shellfish for pathogenic microorganisms that naturally occur in marine ecosystems. Images PMID:6742824

Faghri, M A; Pennington, C L; Cronholm, L S; Atlas, R M

1984-01-01

127

Snow in the city as a spore bank of potentially pathogenic fungi.  

PubMed

This study evaluates the role of snow as a specific ecological niche and a vector in fungal spreading with particular emphasis on potential pathogens in seasonally and daily changing conditions. The experimental material was fungi isolated from the atmospheric air, snow cover, and fragments of ice and soil from underneath the snow cover. The total count of microfungi in the air before snowfall, i.e. in the autumn, reached 1756.1 CFU/m(3) on average. After the first snowfalls, it dropped to 85.2 CFU/m(3). The analyzed samples of snow cover contained from 101.6 to 8500.0 CFU/m(3) of fungi. Furthermore, 26 species of yeast and yeast-like fungi were isolated from the experimental material. Amongst the analyzed species, 13 were potential anthropopathogens. Though another three species were isolated from organ ontocenoses, i.e. Candida intermedia, Saccharomyces bayanus and Zygosaccharomyces rouxii, their pathogenic potential has not yet been explicitly confirmed. The results of the presented study may be applied in predicting concentrations of fungal spores responsible for mycoses. The first snowfalls significantly reduced the number of colony-forming units of fungi in the air. Under conditions of temperate climate, snow becomes a temporary bank of yeast-like fungi spores and while it melts cells of deposited microfungi migrate to the atmosphere. Hence, individuals with impaired immunity or in the course of immunosuppression or recovery should avoid long walks during periods of snow melting. The count of fungi in urban bioaerosol during the melt may be reduced through systematic removal of snow cover, which is a significant reservoir of potential pathogens. In addition, it should be noted that even a typical psychrophilic strain, capable of surviving at a temperature of 37°C, may bear a significant pathogenic potential. PMID:24176713

Ejdys, El?bieta; Biedunkiewicz, Anna; Dynowska, Maria; Sucharzewska, Ewa

2014-02-01

128

Surveillance for emerging respiratory viruses.  

PubMed

Several new viral respiratory tract infectious diseases with epidemic potential that threaten global health security have emerged in the past 15 years. In 2003, WHO issued a worldwide alert for an unknown emerging illness, later named severe acute respiratory syndrome (SARS). The disease caused by a novel coronavirus (SARS-CoV) rapidly spread worldwide, causing more than 8000 cases and 800 deaths in more than 30 countries with a substantial economic impact. Since then, we have witnessed the emergence of several other viral respiratory pathogens including influenza viruses (avian influenza H5N1, H7N9, and H10N8; variant influenza A H3N2 virus), human adenovirus-14, and Middle East respiratory syndrome coronavirus (MERS-CoV). In response, various surveillance systems have been developed to monitor the emergence of respiratory-tract infections. These include systems based on identification of syndromes, web-based systems, systems that gather health data from health facilities (such as emergency departments and family doctors), and systems that rely on self-reporting by patients. More effective national, regional, and international surveillance systems are required to enable rapid identification of emerging respiratory epidemics, diseases with epidemic potential, their specific microbial cause, origin, mode of acquisition, and transmission dynamics. PMID:25189347

Al-Tawfiq, Jaffar A; Zumla, Alimuddin; Gautret, Philippe; Gray, Gregory C; Hui, David S; Al-Rabeeah, Abdullah A; Memish, Ziad A

2014-10-01

129

Local adaptation and evolutionary potential along a temperature gradient in the fungal pathogen Rhynchosporium commune  

PubMed Central

To predict the response of plant pathogens to climate warming, data are needed on current thermal adaptation, the pathogen's evolutionary potential, and the link between them. We conducted a common garden experiment using isolates of the fungal pathogen Rhynchosporium commune from nine barley populations representing climatically diverse locations. Clonal replicates of 126 genetically distinct isolates were assessed for their growth rate at 12°C, 18°C, and 22°C. Populations originating from climates with higher monthly temperature variation had higher growth rate at all three temperatures compared with populations from climates with less temperature fluctuation. Population differentiation in growth rate (QST) was significantly higher at 22°C than population differentiation for neutral microsatellite loci (GST), consistent with local adaptation for growth at higher temperatures. At 18°C, we found evidence for stabilizing selection for growth rate as QST was significantly lower than GST. Heritability of growth rate under the three temperatures was substantial in all populations (0.58–0.76). Genetic variation was lower in populations with higher growth rate at the three temperatures and evolvability increased under heat stress in seven of nine populations. Our findings imply that the distribution of this pathogen is unlikely to be genetically limited under climate warming, due to its high genetic variation and plasticity for thermal tolerance. PMID:23745143

Stefansson, Tryggvi S; McDonald, Bruce A; Willi, Yvonne

2013-01-01

130

Local adaptation and evolutionary potential along a temperature gradient in the fungal pathogen Rhynchosporium commune.  

PubMed

To predict the response of plant pathogens to climate warming, data are needed on current thermal adaptation, the pathogen's evolutionary potential, and the link between them. We conducted a common garden experiment using isolates of the fungal pathogen Rhynchosporium commune from nine barley populations representing climatically diverse locations. Clonal replicates of 126 genetically distinct isolates were assessed for their growth rate at 12°C, 18°C, and 22°C. Populations originating from climates with higher monthly temperature variation had higher growth rate at all three temperatures compared with populations from climates with less temperature fluctuation. Population differentiation in growth rate (Q ST) was significantly higher at 22°C than population differentiation for neutral microsatellite loci (G ST), consistent with local adaptation for growth at higher temperatures. At 18°C, we found evidence for stabilizing selection for growth rate as Q ST was significantly lower than G ST. Heritability of growth rate under the three temperatures was substantial in all populations (0.58-0.76). Genetic variation was lower in populations with higher growth rate at the three temperatures and evolvability increased under heat stress in seven of nine populations. Our findings imply that the distribution of this pathogen is unlikely to be genetically limited under climate warming, due to its high genetic variation and plasticity for thermal tolerance. PMID:23745143

Stefansson, Tryggvi S; McDonald, Bruce A; Willi, Yvonne

2013-04-01

131

Comparison of contact patterns relevant for transmission of respiratory pathogens in Thailand and the Netherlands using respondent-driven sampling.  

PubMed

Understanding infection dynamics of respiratory diseases requires the identification and quantification of behavioural, social and environmental factors that permit the transmission of these infections between humans. Little empirical information is available about contact patterns within real-world social networks, let alone on differences in these contact networks between populations that differ considerably on a socio-cultural level. Here we compared contact network data that were collected in the Netherlands and Thailand using a similar online respondent-driven method. By asking participants to recruit contact persons we studied network links relevant for the transmission of respiratory infections. We studied correlations between recruiter and recruited contacts to investigate mixing patterns in the observed social network components. In both countries, mixing patterns were assortative by demographic variables and random by total numbers of contacts. However, in Thailand participants reported overall more contacts which resulted in higher effective contact rates. Our findings provide new insights on numbers of contacts and mixing patterns in two different populations. These data could be used to improve parameterisation of mathematical models used to design control strategies. Although the spread of infections through populations depends on more factors, found similarities suggest that spread may be similar in the Netherlands and Thailand. PMID:25423343

Stein, Mart L; van Steenbergen, Jim E; Buskens, Vincent; van der Heijden, Peter G M; Chanyasanha, Charnchudhi; Tipayamongkholgul, Mathuros; Thorson, Anna E; Bengtsson, Linus; Lu, Xin; Kretzschmar, Mirjam E E

2014-01-01

132

Stem respiratory potential in six softwood and four hardwood tree species in the central cascades of Oregon  

Microsoft Academic Search

Mature and old growth trees of varying sapwood thickness were compared with regard to stem respiration. An increment core-based, laboratory method under controlled temperature was used to measure tissue-level respiration (termed respiratory potential) of ten different tree species. Bark (dead outer and live inner combined), sapwood, and heartwood thickness measurements were used to predict sapwood volume from stem diameter (including

Michele L. Pruyn; Mark E. Harmon; B. L. Gartner

2003-01-01

133

Analysis of the swine tracheobronchial lymph node transcriptomic response to infection with a Chinese highly pathogenic strain of porcine reproductive and respiratory syndrome virus  

PubMed Central

Background Porcine reproductive and respiratory syndrome virus (PRRSV) is a major pathogen of swine worldwide. Emergence in 2006 of a novel highly pathogenic PRRSV (HP-PRRSV) isolate in China necessitated a comparative investigation into the host transcriptome response in tracheobronchial lymph nodes (TBLN) 13 days post-infection with HP-PRRSV rJXwn06, PRRSV strain VR-2332 or sham inocula. RNA from each was prepared for next-generation sequencing. Amplified library constructs were directly sequenced and a list of sequence transcripts and counts was generated using an RNAseq analysis pipeline to determine differential gene expression. Transcripts were annotated and relative abundance was calculated based upon the number of times a given transcript was represented in the library. Results Major changes in transcript abundance occurred in response to infection with either PRRSV strain, each with over 630 differentially expressed transcripts. The largest increase in transcript level for either virus versus sham-inoculated controls were three serum amyloid A2 acute-phase isoforms. However, the degree of up or down-regulation of transcripts following infection with HP-PRRSV rJXwn06 was greater than transcript changes observed with US PRRSV VR-2332. Also, of 632 significantly altered transcripts within the HP-PRRSV rJXwn06 library 55 were up-regulated and 69 were down-regulated more than 3-fold, whilst in the US PRRSV VR-2332 library only 4 transcripts were up-regulated and 116 were down-regulated more than 3-fold. Conclusions The magnitude of differentially expressed gene profiles detected in HP-PRRSV rJXwn06 infected pigs as compared to VR-2332 infected pigs was consistent with the increased pathogenicity of the HP-PRRSV in vivo. PMID:23110781

2012-01-01

134

ZOONOTIC POTENTIAL OF HIGHLY PATHOGENIC AVIAN H7N3 INFLUENZA VIRUSES FROM PAKISTAN  

PubMed Central

H5 and H7 avian influenza viruses can become highly pathogenic in chickens after interspecies transmission. These viruses have transmitted directly to humans from birds in Eurasia and Africa (H5N1), the Netherlands (H7N7), and Canada (H7N3). Here we report antigenic, sequence, and phylogenetic analyses of H7N3 viruses isolated from chickens in Pakistan from 1995 to 2002. We compared the pathogenic and zoonotic potential of the Pakistani viruses in avian and mammalian hosts. In chickens, all of the isolates showed high pathogenicity with poor transmissibility to contact birds. Viral shedding from the trachea and cloaca was equivalent, but cloacal shedding occurred longer; dissemination of virus into the tissues was widespread. In contrast, the viruses replicated poorly in 6-week-old mallard ducks. In mammalian hosts, of the two Pakistani H7N3/02 viruses that caused weight loss, one also caused 40% mortality in mice without prior adaptation, and preliminary experiments in ferrets showed significant virus multiplication in the lungs, intestine, and conjunctiva. We conclude that the H7N3/02 isolates from Pakistan show limited antigenic drift and have evolved slowly during their 8-year circulation in chickens; however, these viruses have the potential to infect mammals. PMID:19535120

Aamir, Uzma B.; Naeem, Khalid; Ahmed, Zaheer; Obert, Caroline A; Franks, John; Krauss, Scott; Seiler, Patrick; Webster, Robert G.

2009-01-01

135

Systems Integration of Biodefense Omics Data for Analysis of Pathogen-Host Interactions and Identification of Potential Targets  

Microsoft Academic Search

The NIAID (National Institute for Allergy and Infectious Diseases) Biodefense Proteomics program aims to identify targets for potential vaccines, therapeutics, and diagnostics for agents of concern in bioterrorism, including bacterial, parasitic, and viral pathogens. The program includes seven Proteomics Research Centers, generating diverse types of pathogen-host data, including mass spectrometry, microarray transcriptional profiles, protein interactions, protein structures and biological reagents.

Peter B. McGarvey; Hongzhan Huang; Raja Mazumder; Jian Zhang; Yongxing Chen; Chengdong Zhang; Stephen Cammer; Rebecca Will; Margie Odle; Bruno Sobral; Margaret Moore; Cathy H. Wu; Jörg Hoheisel

2009-01-01

136

Respiratory Displacement of the Thoracic Aorta: Physiological Phenomenon With Potential Implications for Thoracic Endovascular Repair  

SciTech Connect

The purpose of this study was to assess the magnitude and direction of respiratory displacement of the ascending and descending thoracic aorta during breathing maneuvers. In 11 healthy nonsmokers, dynamic magnetic resonance imaging was performed in transverse orientation at the tracheal bifurcation during maximum expiration and inspiration as well as tidal breathing. The magnitude and direction of aortic displacement was determined relatively to resting respiratory position for the ascending (AA) and descending (DA) aorta. To estimate a respiratory threshold for occurrence of distinct respiratory aortic motion, the latter was related to the underlying change in anterior-posterior thorax diameter. Compound displacement between maximum expiration and inspiration was 24.3 {+-} 6.0 mm for the AA in the left anterior direction and 18.2 {+-} 5.5 mm for the DA in the right anterior direction. The mean respiratory thorax excursion during tidal breathing was 8.9 {+-} 2.8 mm. The respiratory threshold, i.e., the increase in thorax diameter necessary to result in respiratory aortic displacement, was estimated to be 15.7 mm. The data suggest that after a threshold of respiratory thorax excursion is exceeded, respiration is accompanied by significant displacement of the thoracic aorta. Although this threshold may not be reached during tidal breathing in the majority of individuals, segmental differences during forced respiration impact on aortic geometry, may result in additional extrinsic forces on the aortic wall, and may be of significance for aortic prostheses designed for thoracic endovascular aortic repair.

Weber, Tim Frederik, E-mail: tim.weber@med.uni-heidelberg.d [University Medical Center Heidelberg, Department of Diagnostic and Interventional Radiology (Germany); Tetzlaff, Ralf [German Cancer Research Center, Department of Radiology (Germany); Rengier, Fabian [University Medical Center Heidelberg, Department of Diagnostic and Interventional Radiology (Germany); Geisbuesch, Philipp [University Medical Center Heidelberg, Department of Vascular and Endovascular Surgery (Germany); Kopp-Schneider, Annette [German Cancer Research Center, Department of Biostatistics (Germany); Boeckler, Dittmar [University Medical Center Heidelberg, Department of Vascular and Endovascular Surgery (Germany); Eichinger, Monika [German Cancer Research Center, Department of Radiology (Germany); Kauczor, Hans-Ulrich [University Medical Center Heidelberg, Department of Diagnostic and Interventional Radiology (Germany); Tengg-Kobligk, Hendrik von [German Cancer Research Center, Department of Radiology (Germany)

2009-07-15

137

Potential strategies and biosafety protocols used for dual-use research on highly pathogenic influenza viruses  

PubMed Central

Summary Influenza A viruses (IAVs), particularly the highly pathogenic avian influenza (HPAI) H5N1, have posed a substantial threat to public health worldwide. Although the laboratory generation of the mutant influenza virus H5N1 with airborne transmissibility among mammals, which has been considered as a dual-use research, may benefit the development of effective vaccines and therapeutics against the emerging infectious agents, it may also pose threats to national biosecurity, laboratory biosafety, and/or public health. This review introduces the classification and characterization of IAVs, pinpoints historic pandemics and epidemics caused by IAVs, emphasizes the significance and necessity of biosafety, summarizes currently established biosafety-related protocols for IAV research, and provides potential strategies to improve biosafety protocols for dual-use research on the highly pathogenic avian influenza viruses and other emerging infectious agents. PMID:22987727

Du, Lanying; Li, Ye; Gao, Jimin; Zhou, Yusen; Jiang, Shibo

2013-01-01

138

Influenza virus respiratory infection and transmission following ocular inoculation in ferrets  

Technology Transfer Automated Retrieval System (TEKTRAN)

While influenza viruses are a common respiratory pathogen, sporadic reports of conjunctivitis following human infection demonstrates the ability of this virus to cause disease outside of the respiratory tract. The ocular surface represents both a potential site of virus replication and a portal of e...

139

Making vaccines "on demand": a potential solution for emerging pathogens and biodefense?  

PubMed

The integrated US Public Health Emergency Medical Countermeasures Enterprise (PHEMCE) has made great strides in strategic preparedness and response capabilities. There have been numerous advances in planning, biothreat countermeasure development, licensure, manufacturing, stockpiling and deployment. Increased biodefense surveillance capability has dramatically improved, while new tools and increased awareness have fostered rapid identification of new potential public health pathogens. Unfortunately, structural delays in vaccine design, development, manufacture, clinical testing and licensure processes remain significant obstacles to an effective national biodefense rapid response capability. This is particularly true for the very real threat of "novel pathogens" such as the avian-origin influenzas H7N9 and H5N1, and new coronaviruses such as hCoV-EMC. Conventional approaches to vaccine development, production, clinical testing and licensure are incompatible with the prompt deployment needed for an effective public health response. An alternative approach, proposed here, is to apply computational vaccine design tools and rapid production technologies that now make it possible to engineer vaccines for novel emerging pathogen and WMD biowarfare agent countermeasures in record time. These new tools have the potential to significantly reduce the time needed to design string-of-epitope vaccines for previously unknown pathogens. The design process-from genome to gene sequence, ready to insert in a DNA plasmid-can now be accomplished in less than 24 h. While these vaccines are by no means "standard," the need for innovation in the vaccine design and production process is great. Should such vaccines be developed, their 60-d start-to-finish timeline would represent a 2-fold faster response than the current standard. PMID:23877094

De Groot, Anne S; Einck, Leo; Moise, Leonard; Chambers, Michael; Ballantyne, John; Malone, Robert W; Ardito, Matthew; Martin, William

2013-09-01

140

Genomic analysis and pathogenic characteristics of Type 2 porcine reproductive and respiratory syndrome virus nsp2 deletion strains isolated in Korea.  

PubMed

Porcine reproductive and respiratory syndrome virus (PRRSV) is a globally ubiquitous swine virus that exhibits genetic and pathogenic heterogeneity among isolates. The present study was conducted to determine the complete genome sequence and pathogenicity of two Korean type 2 PRRSV nonstructural protein 2 (nsp2) deletion mutants, CA-2 and KNU-12-KJ4. The full-length genomes of CA-2 and KNU-12-KJ4 were determined to be 15,018 and 15,019 nucleotides in length, excluding the poly(A) tail, respectively, which were 393- or 392-nucleotide shorter than that of the type 2 NA prototype strain VR-2332 due to the presence of notable large deletions within the nsp2 gene. The genomes of CA-2 and KNU-12-KJ4 consisted of a 189- or 190-nucleotide 5' untranslated region (UTR), a 14,677-nucleotide protein-coding region, and a 151-nucleotide 3' UTR. Whole genome evaluation revealed that the nucleotide sequences of CA-2 and KNU-12-KJ4 are most similar to each other (10.7% sequence divergence), and then to the Korean strain CA-1 (11.3% sequence divergence) and the US strain MN184C (13.1% sequence divergence), respectively. To evaluate the in vitro immunity of nsp2 deletion variants, we sought to explore alteration of inflammatory cytokine and chemokine expression in PAM-pCD163 cells infected with each virus strain using quantitative real-time RT-PCR. Cytokine genes including IL-8, IL-10, and TNF-?, and chemokines such as MCP-1 and RANTES were found to be significantly elevated in nsp2 deletion virus-infected PAM cells. In contrast, expression of interferons (IFN-?, ?, and ?) and antiviral genes including ISG-15, -54, and -56 were unchanged or down-regulated in PAM cells infected with the nsp2 deletion mutants. Animal studies to assess the pathogenicity of nsp2 deletion PRRSVs demonstrated that both CA-2 and KNU-12-KJ4 strains notably produce weight loss in infected pigs. Furthermore, the nsp2 deletion mutants replicated well in pigs with significantly increased and prolonged viremia kinetics. Taken together, our results indicate that, among the three isolates, the outcome of in vitro and in vivo infection by CA-2 and KNU-12-KJ4 is comparable, suggesting that the large nsp2 deletion may be one of the viral genetic determinants contributing to PRRSV pathogenicity. PMID:24646599

Choi, Hwan-Won; Nam, Eeuri; Lee, Yoo Jin; Noh, Yun-Hee; Lee, Seung-Chul; Yoon, In-Joong; Kim, Hyun-Soo; Kang, Shien-Young; Choi, Young-Ki; Lee, Changhee

2014-06-01

141

Microbial community composition and respiratory potential of deep, subpermafrost brine in the Canadian Arctic  

NASA Astrophysics Data System (ADS)

Saline fracture waters were collected at depths between 800 and 1200 meters from the Lupin gold mine. Microbial community composition was measured by phospholipid fatty acid analysis. Biomass estimates were from less than 0.1 to 22 pmol/L which converts to 1,700 to 545,000 cells/L. Phospholipid compositions reveal large proportions (24 to 60 mole percent) of monounsatruates, which points to a predominance of Gram negative bacteria. Terminally branched and mid-branched saturates, which indicate Gram positive bacteria, were present at 5-19 mole percent and 0 to 7 mole percent, respectively. The cyclopropyl to monounsaturated fatty acid ratios indicate that the bacterial communities are physiologically stressed. Respiratory potential was estimated by examining the ubiquinone and menaquinone compositions of the water samples. Menaquinone 7 was the most prominent followed by menaquinone 6. Together these two quinones represented 88 to 96 percent of the quinone profile. Ubiquinone 6 represented 0.4 to 11 percent of the quinone profile. The ratio of ubiquinone to menaquinone ranged from 0.003 to 0.066 which indicates that these waters have been exposed to anoxic conditions for a long time.

Pfiffner, S. M.; Smithgall, A.; Parsons, A.; Gan, M.; White, D. C.; Onstott, T. C.; Pratt, L.

2005-12-01

142

Aerobic bacterial oral flora of garter snakes: development of normal flora and pathogenic potential for snakes and humans.  

PubMed Central

Garter snakes that are used for scientific laboratory studies or kept as exotic pets often become ill and die early in captivity. They may also act as reservoirs of potential human pathogens or transmit infection to man. A total of 126 strains of aerobic and facultative bacteria, most potential human and snake pathogens, were isolated from 82 garter snake oropharyngeal cultures. Coagulase-negative Staphylococcus species were the most common species isolated. Acinetobacter calcoaceticus var. anitratus, Hafnia alvei, Arizona hinshawii, Salmonella species, Shigella species, Klebsiella oxytoca, and Pseudomonas aeruginosa were among the potential pathogens isolated. The spectrum of bacteria with potential for causing oral and pulmonary infections in garter snakes is greater than has been previously appreciated. Garter snakes should also be considered reservoirs of human pathogens, and appropriate precautions should be taken by laboratory personnel and pet owners. PMID:7240404

Goldstein, E J; Agyare, E O; Vagvolgyi, A E; Halpern, M

1981-01-01

143

Evaluation of the Efficacy of an Attenuated Live Vaccine against Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus in Young Pigs  

PubMed Central

Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) is characterized by high fever and high mortality in pigs of all ages and has severely affected the pork industry of China in the last few years. An attenuated HP-PRRSV strain, TJM, was obtained by passaging HP-PRRSV strain TJ on MARC-145 cells for 92 passages. Porcine reproductive and respiratory syndrome virus (PRRSV)- and antibody-free pigs were inoculated intramuscularly with TJM (105.0 50% tissue culture infective doses [TCID50]) and challenged at 28, 60, 120, and 180 days postimmunization (dpi). The results showed that 5/5, 5/5, 5/5, and 4/5 immunized pigs were protected from the lethal challenge and did not develop fever and clinical diseases at each challenge, respectively. Compared to control pigs, vaccinated pigs showed much milder pathological lesions and gained significantly more weight (P < 0.01). Sequence analysis of different passages of strain TJ showed that the attenuation resulted in a deletion of a continuous 120 amino acids (aa), in addition to the discontinuous 30-aa deletion in the nsp2 region. The analysis also demonstrated that the 120-aa deletion was genetically stable in vivo. These results suggested that HP-PRRSV TJM was efficacious against a lethal challenge with a virulent HP-PRRSV strain, and effective protection could last at least 4 months. Therefore, strain TJM is a good candidate for an efficacious modified live virus vaccine as well as a useful molecular marker vaccine against HP-PRRSV. PMID:22695163

Leng, Xue; Li, Zhenguang; Xia, Mingqi; He, Yanliang

2012-01-01

144

Bacillus amyloliquefaciens G1: A Potential Antagonistic Bacterium against Eel-Pathogenic Aeromonas hydrophila  

PubMed Central

Recent studies have revealed that the use of probiotics is an alternative to control marine aeromonas. However, few probiotics are available against Aeromonas hydrophila infections in eels. In the present study, a potential antagonistic strain G1 against the eel-pathogenic A. hydrophila was isolated from sediment underlying brackish water. Its extracellular products with antibacterial activities were shown to be stable under wide range of pH, temperature, and proteinase K. It was initially identified as Bacillus amyloliquefaciens using API identification kits and confirmed to be B. amyloliquefaciens strain (GenBank accession number DQ422953) by phylogenetic analysis. In addition, it was shown to be safe for mammalians, had a wide anti-A. hydrophila spectrum, and exhibited significant effects on inhibiting the growth of the eel-pathogenic A. hydrophila both in vitro and in vivo. To the best of our knowledge, this is the first report on a promising antagonistic Bacillus amyloliquefaciens strain from brackish water sediment against eel-pathogenic A. hydrophila. PMID:21754944

Cao, Haipeng; He, Shan; Wei, Ruopeng; Diong, Marek; Lu, Liqun

2011-01-01

145

Potentially Pathogenic Bacteria in Shower Water and Air of a Stem Cell Transplant Unit?  

PubMed Central

Potential pathogens from shower water and aerosolized shower mist (i.e., shower aerosol) have been suggested as an environmental source of infection for immunocompromised patients. To quantify the microbial load in shower water and aerosol samples, we used culture, microscopic, and quantitative PCR methods to investigate four shower stalls in a stem cell transplant unit at Barnes-Jewish Hospital in St. Louis, MO. We also tested membrane-integrated showerheads as a possible mitigation strategy. In addition to quantification, a 16S rRNA gene sequencing survey was used to characterize the abundant bacterial populations within shower water and aerosols. The average total bacterial counts were 2.2 × 107 cells/liter in shower water and 3.4 × 104 cells/m3 in shower aerosol, and these counts were reduced to 6.3 × 104 cells/liter (99.6% efficiency) and 8.9 × 103 cells/m3 (82.4% efficiency), respectively, after membrane-integrated showerheads were installed. Potentially pathogenic organisms were found in both water and aerosol samples from the conventional showers. Most notable was the presence of Mycobacterium mucogenicum (99.5% identity) in the water and Pseudomonas aeruginosa (99.3% identity) in the aerosol samples. Membrane-integrated showerheads may protect immunocompromised patients from waterborne infections in a stem cell transplant unit because of efficient capture of vast numbers of potentially pathogenic bacteria from hospital water. However, an in-depth epidemiological study is necessary to investigate whether membrane-integrated showerheads reduce hospital-acquired infections. The microbial load in shower aerosols with conventional showerheads was elevated compared to the load in HEPA-filtered background air in the stem cell unit, but it was considerably lower than typical indoor air. Thus, in shower environments without HEPA filtration, the increase in microbial load due to shower water aerosolization would not have been distinguishable from anticipated variations in background levels. PMID:19581474

Perkins, Sarah D.; Mayfield, Jennie; Fraser, Victoria; Angenent, Largus T.

2009-01-01

146

Activation of cytokines and NF-kappa B in corneal epithelial cells infected by respiratory syncytial virus: potential relevance in ocular inflammation and respiratory infection  

Microsoft Academic Search

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infection, claiming millions of lives annually. The virus infects various cells of the respiratory tract as well as resident inflammatory cells such as macrophages. Infection activates a variety of cellular factors such as cytokines and the pro-inflammatory transcription factor, NF-kappa B, all of which are important players

Vira Bitko; Nicolle E Garmon; Tin Cao; Benjamin Estrada; John E Oakes; Robert N Lausch; Sailen Barik

2004-01-01

147

Cell Damage at the Origin of Antiphospholipid Antibodies and Their Pathogenic Potential in Recurrent Pregnancy Loss  

PubMed Central

Antiphospholipid antibodies (APA) are associated with thrombosis, thrombocytopenia and fetal loss but they occur in a variety of diseases. Despite many efforts, a correlation between the specificity of particular subgroups of APA and particular clinical situations remains to be established. The antigens at the origin of APA remain to be identified. We discuss here the possible links between cell apoptosis or necrosis, leading to plasma membrane alterations, and the occurrence of APA in response to sustained stimulation. The pathogenic potential of APA is also considered with respect to recurrent pregnancy loss. PMID:18476171

Piroux, Véronique; Eschwège, Valérie

1997-01-01

148

Evaluation of the pathogenic potential of Rickettsia canada and Rickettsia prowazekii organisms in dogs.  

PubMed

An unusual pattern of seroreactivity to antigens of rickettsial organisms (Rickettsia rickettsii, R rhipicephali, R montana, and R bellii), particularly to R bellii antigen, was detected in 3 dogs during a 2-month period. Thus, studies were initiated to clarify the pathogenic potential of the more distantly related rickettsial organisms (R canada and R prowazekii) in dogs. Because R bellii are nonpathogenic rickettsiae that share numerous common properties with spotted fever-group and typhus-group rickettsiae, and because closely related pathogenic relatives of R bellii have not been identified, we examined the pathogenic potential of these typhus-group rickettsiae by testing stored serum samples, by attempting rickettsial isolation from febrile dogs, and by experimentally inoculating dogs with R canada and R prowazekii. Evaluation of results of a serosurvey of acute and convalescent serum samples from 80 dogs in which Rocky Mountain spotted fever had been considered as a differential diagnosis, but seroconversion to R rickettsii had not been documented, identified 1 dog with a fourfold increase in antibody titer to R rhipicephali and 3 dogs with fourfold increases in antibody titer to 1 or more antigens of typhus-group rickettsial organisms. A study of 15 dogs that were febrile during summer months failed to identify serologic or tissue culture evidence of typhus-group rickettsial infection or typhus-group rickettsemia, but did result in isolation of R rickettsii and Ehrlichia canis, respectively, from 1 dog each. In our final study, after experimentally inoculating 6 dogs with R canada and R prowazekii, all dogs seroconverted to the respective rickettsiae, but rickettsemia or clinical and hematologic evidence of disease was not observed.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7601694

Breitschwerdt, E B; Hegarty, B C; Davidson, M G; Szabados, N S

1995-07-01

149

Dynamics and evolution of highly pathogenic porcine reproductive and respiratory syndrome virus following its introduction into a herd concurrently infected with both types 1 and 2.  

PubMed

Since its first emergence in Thailand in late 2010, highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) has caused sporadic outbreaks on Thai swine farms. The objective of this study was to investigate the dynamics and evolution of PRRSV in a herd experiencing an HP-PRRSV outbreak. Following its introduction, HP-PRRSV caused severe outbreaks and subsequently established persistent infection in the herd, resulting in the emergence of a novel cluster of type 2 (North American, NA) isolates. HP-PRRSV co-existed with type 1 (European, EU) isolates without influencing their development. In contrast, HP-PRRSV influenced the evolution of the type 2 (NA) isolates by increasing diversity through the addition of a novel cluster and influencing the evolution of other viral clusters previously existing in the herd. Recombination between the endemic and emerging isolates was observed. The recombinants, however, disappeared and were not able to survive in the herd. The results of this study suggest that the introduction of HP-PRRSV to a herd results in an increased diversity of genetically related isolates and persistent HP-PRRSV infection. PMID:25557456

Chaikhumwang, Puwich; Tantituvanont, Angkana; Tripipat, Thitima; Tipsombatboon, Pavita; Piriyapongsa, Jittima; Nilubol, Dachrit

2015-03-01

150

Integrated DNA and RNA extraction and purification on an automated microfluidic cassette from bacterial and viral pathogens causing community-acquired lower respiratory tract infections.  

PubMed

In this paper, we describe the development of an automated sample preparation procedure for etiological agents of community-acquired lower respiratory tract infections (CA-LRTI). The consecutive assay steps, including sample re-suspension, pre-treatment, lysis, nucleic acid purification, and concentration, were integrated into a microfluidic lab-on-a-chip (LOC) cassette that is operated hands-free by a demonstrator setup, providing fluidic and valve actuation. The performance of the assay was evaluated on viral and Gram-positive and Gram-negative bacterial broth cultures previously sampled using a nasopharyngeal swab. Sample preparation on the microfluidic cassette resulted in higher or similar concentrations of pure bacterial DNA or viral RNA compared to manual benchtop experiments. The miniaturization and integration of the complete sample preparation procedure, to extract purified nucleic acids from real samples of CA-LRTI pathogens to, and above, lab quality and efficiency, represent important steps towards its application in a point-of-care test (POCT) for rapid diagnosis of CA-LRTI. PMID:24615272

Van Heirstraeten, Liesbet; Spang, Peter; Schwind, Carmen; Drese, Klaus S; Ritzi-Lehnert, Marion; Nieto, Benjamin; Camps, Marta; Landgraf, Bryan; Guasch, Francesc; Corbera, Antoni Homs; Samitier, Josep; Goossens, Herman; Malhotra-Kumar, Surbhi; Roeser, Tina

2014-05-01

151

Comparative analysis of apoptotic changes in peripheral immune organs and lungs following experimental infection of piglets with highly pathogenic and classical porcine reproductive and respiratory syndrome virus  

PubMed Central

Background Our previous studies have demonstrated that piglets infected with highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) may develop significant thymus atrophy, which related to thymocytes apoptosis. However, apart from that detected in the thymus, there are no reports describing cell apoptosis induced by HP-PRRSV infection. In this study, we analyzed comparatively the pathological changes, cell apoptosis and viral load in peripheral immune organs including tonsil, inguinal lymph nodes (ILNs) and spleen and lungs following experimental infection of piglets with HP-PRRSV HuN4 and classical PRRSV CH-1a. Findings HP-PRRSV HuN4 exhibited much stronger cell tropism than CH-1a in immune organs and lungs of piglets. HuN4 infection led to the serious injuries in tonsils, ILNs, spleens and lungs, especially apoptosis in these organs was significant. Conclusions HuN4 infection induced severe lesions (gross pathology, histopathology and cell apoptosis) in the peripheral immune organs and lungs of infected piglets. Large numbers of apoptotic cells in immune organs and lung induced by HuN4 may play a role in the pathogenesis of the HP-PRRS and the distinct injuries caused by HuN4 infection may be associated with the high mortality rate of HP-PRRS in pigs. PMID:24393149

2014-01-01

152

In vitro antimicrobial and anticancer potential of hinokitiol against oral pathogens and oral cancer cell lines.  

PubMed

Hinokitiol is a natural component isolated from Chamacyparis taiwanensis. It has anti-microbial activity, and has been used in oral care products. The minimal inhibitory concentration (MIC) and minimal microbicidal concentration (MMC) of hinokitiol against MRSA, Aggregatibacter actinomycetemcomitans, Streptococcus mutans, and Candida albicans were determined by the agar and broth dilution method (MIC: 40-110?M; MMC: 50-130?M); the paradoxical inhibition phenomenon (PIP) was observed in A. actinomycetemcomitans and S. mutans. The PIP can be described as microbial growth occurring in the presence of both high and low concentrations of a compound, between which microbial growth is inhibited. The PIP was confirmed using a kinetic microplate and inhibition zone methods. The PIP was also observed in MRSA. The low autolysin activity somehow correlated to the PIP positive. The cell diameter was increased in all the pathogens, and the transition was inhibited in C. albicans following hinokitiol treatment. Hinokitiol is also a potential anticancer drug. The 200?M of hinokitiol has significant antimicrobial and cytotoxic activities against oral pathogens and oral squamous cell carcinoma cell lines, respectively, and lower cytotoxic effects for normal human oral keratinocytes, indicating that hinokitiol displays a high potential for safe and effective applications in oral health care. PMID:23312825

Shih, Yin-Hua; Chang, Kuo-Wei; Hsia, Shih-Min; Yu, Cheng-Chia; Fuh, Lih-Jyh; Chi, Tzu-Yun; Shieh, Tzong-Ming

2013-06-12

153

Local IL-17A Potentiates Early Neutrophil Recruitment to the Respiratory Tract during Severe RSV Infection  

PubMed Central

Respiratory syncytial virus (RSV) bronchiolitis triggers a strong innate immune response characterized by excessive neutrophil infiltration which contributes to RSV induced pathology. The cytokine IL-17A enhances neutrophil infiltration into virus infected lungs. IL-17A is however best known as an effector of adaptive immune responses. The role of IL-17A in early immune modulation in RSV infection is unknown. We aimed to elucidate whether local IL-17A facilitates the innate neutrophil infiltration into RSV infected lungs prior to adaptive immunity. To this end, we studied IL-17A production in newborns that were hospitalized for severe RSV bronchiolitis. In tracheal aspirates we measured IL-17A concentration and neutrophil counts. We utilized cultured human epithelial cells to test if IL-17A regulates RSV infection-induced IL-8 release as mediator of neutrophil recruitment. In mice we investigated the cell types that are responsible for early innate IL-17A production during RSV infection. Using IL-17A neutralizing antibodies we tested if IL-17A is responsible for innate neutrophil infiltration in mice. Our data show that increased IL-17A production in newborn RSV patient lungs correlates with subsequent neutrophil counts recruited to the lungs. IL-17A potentiates RSV-induced production of the neutrophil-attracting chemokine IL-8 by airway epithelial cells in vitro. Various lung-resident lymphocytes produced IL-17A during early RSV infection in Balb/c mice, of which a local population of CD4 T cells stood out as the predominant RSV-induced cell type. By removing IL-17A during early RSV infection in mice we showed that IL-17A is responsible for enhanced innate neutrophil infiltration in vivo. Using patient material, in vitro studies, and an animal model of RSV infection, we thus show that early local IL-17A production in the airways during RSV bronchiolitis facilitates neutrophil recruitment with pathologic consequences to infant lungs. PMID:24194936

Stoppelenburg, Arie Jan; Salimi, Vahid; Hennus, Marije; Plantinga, Maud; Huis in ’t Veld, Ron; Walk, Jona; Meerding, Jenny; Coenjaerts, Frank; Bont, Louis; Boes, Marianne

2013-01-01

154

Aeroallergens and viable microbes in sandstorm dust. Potential triggers of allergic and nonallergic respiratory ailments.  

PubMed

Aeroallergens and antigens in sandstorm dust, extracts of which were skin prick test (SPT) positive in allergic patients, were detected by rocket immunoelectrophoresis and ELISA. Fungi and bacteria isolated by agar settle plates and soil dilution and soil washing methods were enumerated and identified. Cat dander, Acacia, Alternaria, Aspergillus, Chenopodium, Cladosporium, Bermuda grass, Pithecellobium, Prosopis, Rumex, cultivated rye, and Washingtonia palm allergens were detected by both methods. Viable microbes including 1892 +/- 325 colony-forming units (cfu) of bacteria, and 869 +/- 75 cfu of fungi were isolated per gram of dust by the soil dilution method. Randomly selected microbial colonies on streaking and subculture were found to consist of between two and seven mixed colonies. Fungi including Alternaria, Aspergillus, Botrytis, Cladosporium, Mortierella, Mucor, Mycelia sterilia, Penicillium, Pythium, Ulocladium, Verticillium, and some yeasts were isolated. Actinomyces, Bacillus, Pseudomonas, and mostly coagulase-negative Staphylococcus species were identified, but the bulk of unidentified bacterial isolates were mainly mixed colonies of rods, cocci, coccobacilli, and some filamentous types. Six-hour agar settle-plate counts during sandstorms were 100 and 40% higher for bacteria and fungi, respectively, than without sandstorms. The most abundant aeroallergens were those of Acacia, Alternaria, Aspergillus, Bermuda grass, Cladosporium, cultivated rye, Prosopis, and cat dander. Pithecellobium dulce, Rumex crispus, and Washingtonia palm allergens were detectable for the first time in Riyadh. IgE reactivities of the dust in man were demonstrated by ELISA using sera from atopic, exposed, and normal subjects. These results indicate that sandstorm dust is a prolific source of potential triggers of allergic and nonallergic respiratory ailments, and the methods mentioned here should be routinely used for quick sampling of the environment. PMID:9542605

Kwaasi, A A; Parhar, R S; al-Mohanna, F A; Harfi, H A; Collison, K S; al-Sedairy, S T

1998-03-01

155

Potential applications of cryogenic technologies to plant genetic improvement and pathogen eradication.  

PubMed

Rapid increases in human populations provide a great challenge to ensure that adequate quantities of food are available. Sustainable development of agricultural production by breeding more productive cultivars and by increasing the productive potential of existing cultivars can help meet this demand. The present paper provides information on the potential uses of cryogenic techniques in ensuring food security, including: (1) long-term conservation of a diverse germplasm and successful establishment of cryo-banks; (2) maintenance of the regenerative ability of embryogenic tissues that are frequently the target for genetic transformation; (3) enhancement of genetic transformation and plant regeneration of transformed cells, and safe, long-term conservation for transgenic materials; (4) production and maintenance of viable protoplasts for transformation and somatic hybridization; and (5) efficient production of pathogen-free plants. These roles demonstrate that cryogenic technologies offer opportunities to ensure food security. PMID:24681087

Wang, Biao; Wang, Ren-Rui; Cui, Zhen-Hua; Bi, Wen-Lu; Li, Jing-Wei; Li, Bai-Quan; Ozudogru, Elif Aylin; Volk, Gayle M; Wang, Qiao-Chun

2014-01-01

156

Recombinant Kluyveromyces lactis expressing highly pathogenic porcine reproductive and respiratory syndrome virus GP5 elicits mucosal and cell-mediated immune responses in mice  

PubMed Central

Currently, killed-virus and modified-live porcine reproductive and respiratory syndrome virus (PRRSV) vaccines are used to control porcine reproductive and respiratory syndrome. However, both types of vaccines have inherent drawbacks; accordingly, the development of novel PRRSV vaccines is urgently needed. Previous studies have suggested that yeast possesses adjuvant activities, and it has been used as an expression vehicle to elicit immune responses to foreign antigens. In this report, recombinant Kluyveromyces lactis expressing GP5 of HP-PRRSV (Yeast-GP5) was generated and immune responses to this construct were analyzed in mice. Intestinal mucosal PRRSV-specific sIgA antibody and higher levels of IFN-? in spleen CD4+ and CD8+ T cells were induced by oral administration of Yeast-GP5. Additionally, Yeast-GP5 administered subcutaneously evoked vigorous cell-mediated immunity, and PRRSV-specific lymphocyte proliferation and IFN-? secretion were detected in the splenocytes of mice. These results suggest that Yeast-GP5 has the potential for use as a vaccine for PRRSV in the future. PMID:24378591

Zhao, Haiyan; Wang, Yalan; Ma, Zhitao; Wang, Yongqiang

2014-01-01

157

The Relationship between Host Lifespan and Pathogen Reservoir Potential: An Analysis in the System Arabidopsis thaliana-Cucumber mosaic virus  

PubMed Central

Identification of the determinants of pathogen reservoir potential is central to understand disease emergence. It has been proposed that host lifespan is one such determinant: short-lived hosts will invest less in costly defenses against pathogens, so that they will be more susceptible to infection, more competent as sources of infection and/or will sustain larger vector populations, thus being effective reservoirs for the infection of long-lived hosts. This hypothesis is sustained by analyses of different hosts of multihost pathogens, but not of different genotypes of the same host species. Here we examined this hypothesis by comparing two genotypes of the plant Arabidopsis thaliana that differ largely both in life-span and in tolerance to its natural pathogen Cucumber mosaic virus (CMV). Experiments with the aphid vector Myzus persicae showed that both genotypes were similarly competent as sources for virus transmission, but the short-lived genotype was more susceptible to infection and was able to sustain larger vector populations. To explore how differences in defense against CMV and its vector relate to reservoir potential, we developed a model that was run for a set of experimentally-determined parameters, and for a realistic range of host plant and vector population densities. Model simulations showed that the less efficient defenses of the short-lived genotype resulted in higher reservoir potential, which in heterogeneous host populations may be balanced by the longer infectious period of the long-lived genotype. This balance was modulated by the demography of both host and vector populations, and by the genetic composition of the host population. Thus, within-species genetic diversity for lifespan and defenses against pathogens will result in polymorphisms for pathogen reservoir potential, which will condition within-population infection dynamics. These results are relevant for a better understanding of host-pathogen co-evolution, and of the dynamics of pathogen emergence. PMID:25375140

Hily, Jean Michel; García, Adrián; Moreno, Arancha; Plaza, María; Wilkinson, Mark D.; Fereres, Alberto; Fraile, Aurora; García-Arenal, Fernando

2014-01-01

158

Persistence, seasonal dynamics and pathogenic potential of Vibrio communities from Pacific oyster hemolymph.  

PubMed

Bacteria of the genus Vibrio occur at a continuum from free-living to symbiotic life forms, including opportunists and pathogens, that can contribute to severe diseases, for instance summer mortality events of Pacific oysters Crassostrea gigas. While most studies focused on Vibrio isolated from moribund oysters during mortality outbreaks, investigations of the Vibrio community in healthy oysters are rare. Therefore, we characterized the persistence, diversity, seasonal dynamics, and pathogenicity of the Vibrio community isolated from healthy Pacific oysters. In a reciprocal transplant experiment we repeatedly sampled hemolymph from adult Pacific oysters to differentiate population from site-specific effects during six months of in situ incubation in the field. We characterized virulence phenotypes and genomic diversity based on multilocus sequence typing in a total of 70 Vibrio strains. Based on controlled infection experiments we could show that strains with the ability to colonize healthy adult oysters can also have the potential to induce high mortality rates on larvae. Diversity and abundance of Vibrio varied significantly over time with highest values during and after spawning season. Vibrio communities from transplanted and stationary oysters converged over time, indicating that communities were not population specific, but rather assemble from the surrounding environment forming communities, some of which can persist over longer periods. PMID:24728233

Wendling, Carolin C; Batista, Frederico M; Wegner, K Mathias

2014-01-01

159

Enteric bacterial pathogens with zoonotic potential isolated from farm-raised deer.  

PubMed

The raising of captive white-tailed deer (Odocoileus virginianus) is a growing agricultural industry in Ohio as it is in several other areas of the United States and around the world. Pooled fecal samples were collected from 30 white-tailed deer confinement facilities. Samples were cultured for five enteric bacterial pathogens. Premise prevalence rates were as follows: Escherichia coli O157, 3.3%; Listeria monocytogenes, 3.3%; Salmonella enterica, 0%; Yersinia enterocolitica, 30%; and Clostridium difficile, 36.7%. The ail virulence gene could not be amplified from any of the Y. enterocolitica isolates recovered. Toxigenic strains of C. difficile polymerase chain reaction ribotype 078, an emerging C. difficile genotype of humans and food animals, were recovered from 4 of 11 (36.4%) C. difficile-positive deer farms. Venison from farm-raised deer might become contaminated with foodborne pathogens, deer farmers may have occupational exposure to these zoonotic agents, and farm-raised deer could be a reservoir from which the environment and other livestock may become contaminated with a number of potentially zoonotic bacteria. PMID:20575673

French, Elizabeth; Rodriguez-Palacios, Alex; LeJeune, Jeffrey T

2010-09-01

160

Birds as potential reservoirs of tick-borne pathogens: first evidence of bacteraemia with Rickettsia helvetica  

PubMed Central

Background Birds have long been known as carriers of ticks, but data from the literature are lacking on their role as a reservoir in the epidemiology of certain tick-borne disease-causing agents. Therefore, the aim of this study was to evaluate the presence of three emerging, zoonotic tick-borne pathogens in blood samples and ticks of birds and to assess the impact of feeding location preference and migration distance of bird species on their tick infestation. Methods Blood samples and ticks of birds were analysed with TaqMan real-time PCRs and conventional PCR followed by sequencing. Results During the spring and autumn bird migrations, 128 blood samples and 140 ticks (Ixodes ricinus, Haemaphysalis concinna and a Hyalomma specimen) were collected from birds belonging to 16 species. The prevalence of tick infestation and the presence of tick species were related to the feeding and migration habits of avian hosts. Birds were shown to be bacteraemic with Rickettsia helvetica and Anaplasma phagocytophilum, but not with Candidatus Neoehrlichia mikurensis. The prevalence of rickettsiae was high (51.4%) in ticks, suggesting that some of them may have acquired their infection from their avian host. Conclusion Based on the present results birds are potential reservoirs of both I. ricinus transmitted zoonotic pathogens, R. helvetica and A. phagocytophilum, but their epidemiological role appears to be less important concerning the latter, at least in Central Europe. PMID:24679245

2014-01-01

161

Pathogenic, diagnostic and vaccine potential of leptospiral outer membrane proteins (OMPs).  

PubMed

Abstract Pathogenic Leptospira species are important human and animal pathogen that causes leptospirosis, with more than half a million cases reported annually but little is known regarding the true incidence of leptospirosis due to the limitations in diagnosis. Proteins embedded in the outer membrane are found to be prime drug targets due to its key role as receptors for cellular communication and gatekeepers for iron and substrate transport across cell membranes. The major key issues to be addressed to overcome the disease burden of leptospirosis are: need to identify the genes that turn on in vivo; development of rapid diagnostic methods to facilitate the early diagnosis and to develop a universal vaccine. Recent whole genome sequencing of Leptospira species and development of in silico analysis tools have led to the identification of a large number of leptospiral virulence genes, metabolic pathways and surface protein secretion systems that represent potential new targets for the development of anti-leptospiral drug, vaccine and diagnostic strategies. This review surveys the different types of outer membrane proteins (OMPs) of Leptospira and combines all the novel features of OMPs reported till date and put forth some views for future research. PMID:23688248

Raja, Veerapandian; Natarajaseenivasan, Kalimuthusamy

2015-02-01

162

Persistence, Seasonal Dynamics and Pathogenic Potential of Vibrio Communities from Pacific Oyster Hemolymph  

PubMed Central

Bacteria of the genus Vibrio occur at a continuum from free-living to symbiotic life forms, including opportunists and pathogens, that can contribute to severe diseases, for instance summer mortality events of Pacific oysters Crassostrea gigas. While most studies focused on Vibrio isolated from moribund oysters during mortality outbreaks, investigations of the Vibrio community in healthy oysters are rare. Therefore, we characterized the persistence, diversity, seasonal dynamics, and pathogenicity of the Vibrio community isolated from healthy Pacific oysters. In a reciprocal transplant experiment we repeatedly sampled hemolymph from adult Pacific oysters to differentiate population from site-specific effects during six months of in situ incubation in the field. We characterized virulence phenotypes and genomic diversity based on multilocus sequence typing in a total of 70 Vibrio strains. Based on controlled infection experiments we could show that strains with the ability to colonize healthy adult oysters can also have the potential to induce high mortality rates on larvae. Diversity and abundance of Vibrio varied significantly over time with highest values during and after spawning season. Vibrio communities from transplanted and stationary oysters converged over time, indicating that communities were not population specific, but rather assemble from the surrounding environment forming communities, some of which can persist over longer periods. PMID:24728233

Wendling, Carolin C.; Batista, Frederico M.; Wegner, K. Mathias

2014-01-01

163

Antifungal Susceptibility Profiles of 1698 Yeast Reference Strains Revealing Potential Emerging Human Pathogens  

PubMed Central

New molecular identification techniques and the increased number of patients with various immune defects or underlying conditions lead to the emergence and/or the description of novel species of human and animal fungal opportunistic pathogens. Antifungal susceptibility provides important information for ecological, epidemiological and therapeutic issues. The aim of this study was to assess the potential risk of the various species based on their antifungal drug resistance, keeping in mind the methodological limitations. Antifungal susceptibility profiles to the five classes of antifungal drugs (polyens, azoles, echinocandins, allylamines and antimetabolites) were determined for 1698 yeast reference strains belonging to 992 species (634 Ascomycetes and 358 Basidiomycetes). Interestingly, geometric mean minimum inhibitory concentrations (MICs) of all antifungal drugs tested were significantly higher for Basidiomycetes compared to Ascomycetes (p<0.001). Twenty four strains belonging to 23 species of which 19 were Basidiomycetes seem to be intrinsically “resistant” to all drugs. Comparison of the antifungal susceptibility profiles of the 4240 clinical isolates and the 315 reference strains belonging to 53 shared species showed similar results. Even in the absence of demonstrated in vitro/in vivo correlation, knowing the in vitro susceptibility to systemic antifungal agents and the putative intrinsic resistance of yeast species present in the environment is important because they could become opportunistic pathogens. PMID:22396754

Desnos-Ollivier, Marie; Robert, Vincent; Raoux-Barbot, Dorothée; Groenewald, Marizeth; Dromer, Françoise

2012-01-01

164

Health assessment and seroepidemiologic survey of potential pathogens in wild Antillean manatees (Trichechus manatus manatus).  

PubMed

The Antillean manatee (Trichechus manatus manatus), a subspecies of the West Indian manatee, inhabits fresh, brackish, and warm coastal waters distributed along the eastern border of Central America, the northern coast of South America, and throughout the Wider Caribbean Region. Threatened primarily by human encroachment, poaching, and habitat degradation, Antillean manatees are listed as endangered by the International Union for the Conservation of Nature. The impact of disease on population viability remains unknown in spite of concerns surrounding the species' ability to rebound from a population crash should an epizootic occur. To gain insight on the baseline health of this subspecies, a total of 191 blood samples were collected opportunistically from wild Antillean manatees in Belize between 1997 and 2009. Hematologic and biochemical reference intervals were established, and antibody prevalence to eight pathogens with zoonotic potential was determined. Age was found to be a significant factor of variation in mean blood values, whereas sex, capture site, and season contributed less to overall differences in parameter values. Negative antibody titers were reported for all pathogens surveyed except for Leptospira bratislava, L. canicola, and L. icterohemorrhagiae, Toxoplasma gondii, and morbillivirus. As part of comprehensive health assessment in manatees from Belize, this study will serve as a benchmark aiding in early disease detection and in the discernment of important epidemiologic patterns in the manatees of this region. Additionally, it will provide some of the initial tools to explore the broader application of manatees as sentinel species of nearshore ecosystem health. PMID:22984521

Sulzner, Kathryn; Kreuder Johnson, Christine; Bonde, Robert K; Auil Gomez, Nicole; Powell, James; Nielsen, Klaus; Luttrell, M Page; Osterhaus, A D M E; Aguirre, A Alonso

2012-01-01

165

Health assessment and seroepidemiologic survey of potential pathogens in wild Antillean manatees (Trichechus manatus manatus)  

USGS Publications Warehouse

The Antillean manatee (Trichechus manatus manatus), a subspecies of the West Indian manatee, inhabits fresh, brackish, and warm coastal waters distributed along the eastern border of Central America, the northern coast of South America, and throughout the Wider Caribbean Region. Threatened primarily by human encroachment, poaching, and habitat degradation, Antillean manatees are listed as endangered by the International Union for the Conservation of Nature. The impact of disease on population viability remains unknown in spite of concerns surrounding the species' ability to rebound from a population crash should an epizootic occur. To gain insight on the baseline health of this subspecies, a total of 191 blood samples were collected opportunistically from wild Antillean manatees in Belize between 1997 and 2009. Hematologic and biochemical reference intervals were established, and antibody prevalence to eight pathogens with zoonotic potential was determined. Age was found to be a significant factor of variation in mean blood values, whereas sex, capture site, and season contributed less to overall differences in parameter values. Negative antibody titers were reported for all pathogens surveyed except for Leptospira bratislava, L. canicola, and L. icterohemorrhagiae, Toxoplasma gondii, and morbillivirus. As part of comprehensive health assessment in manatees from Belize, this study will serve as a benchmark aiding in early disease detection and in the discernment of important epidemiologic patterns in the manatees of this region. Additionally, it will provide some of the initial tools to explore the broader application of manatees as sentinel species of nearshore ecosystem health.

Sulzner, Kathryn; Johnson, Christine Kreuder; Bonde, Robert K.; Gomez, Nicole Auil; Powell, James; Nielsen, Klaus; Luttrell, M. Page; Osterhaus, A.D.M.E.; Aguirre, A. Alonso

2012-01-01

166

Components of pathogenic Leptospira spp. with potentials for diagnosis of human leptospirosis.  

PubMed

Existing serological methods for diagnosis of leptospirosis are still unsatisfactorily due mainly to their low accuracy. In this study, serum samples of 18 clinically diagnosed-, IgM dipstick positive-, MAT positive-leptospirosis patients (group 1) were analyzed by IgG Western blotting against SDS-PAGE separated-whole cell homogenates of pathogenic and non-pathogenic Leptospira spp. belonging to 20 serovars of 15 serogroups. The samples of group 1 were collected from the patients at days 3 to 10 after the fever onset (fist samples). Second and third samples could be obtained from 4 patients. Sera of the 22 patients with other febrile illnesses (group 2) and 22 healthy counterparts (group 3) were used as patient- and normal- controls, respectively. Irrespective of the serovar or serogroup of the pathogenic Leptospira spp. used as antigen in the Western blotting, all of the 18 sera of patients with leptospirosis (group 1) gave characteristic diffuse antigen-antibody reactive bands located at approximately 35-38 and 22-26 kDa; and thus 100% diagnostic sensitivity of the Western blot assay. Some serum samples of the leptospirosis patients also reacted to components located at 80-100, approximately 70, 60, 54, and 48 kDa. More bands or the early recognized bands with increased intensity were observed when tested the second and third samples. The characteristic bands were not seen when homogenates of L. biflexa, serogroup Semaranga, serovar Patoc (saprophytic) and L. biflexa, serogroup Andamana, serovar Andamana (non-pathogenic but can infect host) were used in the assay. Sera of groups 2 and 3 did not react to the components at the seven locations implying 100% diagnostic specificity of the IgG Western blot assay. While awaiting validation with more patients' samples, the IgG Western Blot analysis aiming at the detection of the characteristic antigen-antibody reactive bands described in this study has high potential for early, rapid, simple and accurate diagnosis of human leptospirosis. PMID:18402296

Saengjaruk, Patcharin; Sakolvaree, Yuwaporn; Maneewatch, Santi; Tomanakan, Kanchana; Tongtawe, Pongsri; Tapchaisri, Pramaun; Chaicumpa, Wanpen

2007-12-01

167

Transient virulence of emerging pathogens  

PubMed Central

Should emerging pathogens be unusually virulent? If so, why? Existing theories of virulence evolution based on a tradeoff between high transmission rates and long infectious periods imply that epidemic growth conditions will select for higher virulence, possibly leading to a transient peak in virulence near the beginning of an epidemic. This transient selection could lead to high virulence in emerging pathogens. Using a simple model of the epidemiological and evolutionary dynamics of emerging pathogens, along with rough estimates of parameters for pathogens such as severe acute respiratory syndrome, West Nile virus and myxomatosis, we estimated the potential magnitude and timing of such transient virulence peaks. Pathogens that are moderately evolvable, highly transmissible, and highly virulent at equilibrium could briefly double their virulence during an epidemic; thus, epidemic-phase selection could contribute significantly to the virulence of emerging pathogens. In order to further assess the potential significance of this mechanism, we bring together data from the literature for the shapes of tradeoff curves for several pathogens (myxomatosis, HIV, and a parasite of Daphnia) and the level of genetic variation for virulence for one (myxomatosis). We discuss the need for better data on tradeoff curves and genetic variance in order to evaluate the plausibility of various scenarios of virulence evolution. PMID:19864267

Bolker, Benjamin M.; Nanda, Arjun; Shah, Dharmini

2010-01-01

168

Mitochondrial Genome Acquisition Restores Respiratory Function and Tumorigenic Potential of Cancer Cells without Mitochondrial DNA.  

PubMed

We report that tumor cells without mitochondrial DNA (mtDNA) show delayed tumor growth, and that tumor formation is associated with acquisition of mtDNA from host cells. This leads to partial recovery of mitochondrial function in cells derived from primary tumors grown from cells without mtDNA and a shorter lag in tumor growth. Cell lines from circulating tumor cells showed further recovery of mitochondrial respiration and an intermediate lag to tumor growth, while cells from lung metastases exhibited full restoration of respiratory function and no lag in tumor growth. Stepwise assembly of mitochondrial respiratory (super)complexes was correlated with acquisition of respiratory function. Our findings indicate horizontal transfer of mtDNA from host cells in the tumor microenvironment to tumor cells with compromised respiratory function to re-establish respiration and tumor-initiating efficacy. These results suggest pathophysiological processes for overcoming mtDNA damage and support the notion of high plasticity of malignant cells. PMID:25565207

Tan, An S; Baty, James W; Dong, Lan-Feng; Bezawork-Geleta, Ayenachew; Endaya, Berwini; Goodwin, Jacob; Bajzikova, Martina; Kovarova, Jaromira; Peterka, Martin; Yan, Bing; Pesdar, Elham Alizadeh; Sobol, Margarita; Filimonenko, Anatolyj; Stuart, Shani; Vondrusova, Magdalena; Kluckova, Katarina; Sachaphibulkij, Karishma; Rohlena, Jakub; Hozak, Pavel; Truksa, Jaroslav; Eccles, David; Haupt, Larisa M; Griffiths, Lyn R; Neuzil, Jiri; Berridge, Michael V

2015-01-01

169

RARE OCCURRENCE OF HETEROTROPHIC BACTERIA WITH PATHOGENIC POTENTIAL IN POTABLE WATER  

EPA Science Inventory

Since the discovery of Legionella pneumophila, an opportunistic pathogen that is indigenous to water, microbiologists have speculated that there may be other opportunistic pathogens among the numerous heterotrophic bacteria found in potable water. The USEPA developed a series of...

170

Ageing and respiratory infections: The airway of ageing.  

PubMed

Respiratory infections are a leading cause of infectious disease burden worldwide especially among the elderly. Furthermore, a direct relationship between ageing and susceptibility to infections has been reported, which may be caused by impaired immune function, frailty and degree of exposure to infectious diseases. Many complex changes, including structural and age-associated decline in immunity are associated with increased pulmonary diseases worldwide and result in a high age-related disease burden. The common respiratory infections that present serious risks for the elderly include influenza, respiratory syncytial virus, and a number of bacterial pathogens including pneumococcus and tuberculosis. Vaccines are available for a limited number of these pathogens including influenza, pneumococcal and pertussis vaccines. This mini review article examines the age-related changes in immune function that predispose the elderly population to respiratory infections and potential loss of vaccine efficacy with a focus on ageing and influenza infections. PMID:24973652

Haq, Kamran; McElhaney, Janet E

2014-11-01

171

Potentially Pathogenic Escherichia coli Can Form a Biofilm under Conditions Relevant to the Food Production Chain  

PubMed Central

The biofilm-producing abilities of potentially human-pathogenic serotypes of Escherichia coli from the ovine reservoir were studied at different temperatures and on different surfaces. A possible influence of the hydrophobicity of the bacterial cells, as well as the presence of two virulence factors, the Shiga toxin-encoding (Stx) bacteriophage and the eae gene, was also studied. A total of 99 E. coli isolates of serotypes O26:H11, O103:H2, and O103:H25 isolated from sheep feces were included. The results show that isolates of all three E. coli serotypes investigated can produce biofilm on stainless steel, glass, and polystyrene at 12, 20, and 37°C. There was a good general correlation between the results obtained on the different surfaces. E. coli O103:H2 isolates produced much more biofilm than those of the other two serotypes at all three temperatures. In addition, isolates of serotype O26:H11 produced more biofilm than those of O103:H25 at 37°C. The hydrophobicity of the isolates varied between serotypes and was also influenced by temperature. The results strongly indicated that hydrophobicity influenced the attachment of the bacteria rather than their ability to form biofilm once attached. Isolates with the eae gene produced less biofilm at 37°C than isolates without this gene. The presence of a Stx bacteriophage did not influence biofilm production. In conclusion, our results show that potentially human-pathogenic E. coli from the ovine reservoir can form biofilm on various surfaces and at several temperatures relevant for food production and handling. PMID:24362422

Sekse, Camilla; Berg, Kristin; Johannesen, Karianne C. S.; Solheim, Heidi; Vestby, Lene K.; Urdahl, Anne Margrete

2014-01-01

172

The Potential for pathogenicity was present in the ancestor of the Ascomycete subphylum Pezizomycotina  

PubMed Central

Background Previous studies in Ascomycetes have shown that the function of gene families of which the size is considerably larger in extant pathogens than in non-pathogens could be related to pathogenicity traits. However, by only comparing gene inventories in extant species, no insights can be gained into the evolutionary process that gave rise to these larger family sizes in pathogens. Moreover, most studies which consider gene families in extant species only tend to explain observed differences in gene family sizes by gains rather than by losses, hereby largely underestimating the impact of gene loss during genome evolution. Results In our study we used a selection of recently published genomes of Ascomycetes to analyze how gene family gains, duplications and losses have affected the origin of pathogenic traits. By analyzing the evolutionary history of gene families we found that most gene families with an enlarged size in pathogens were present in an ancestor common to both pathogens and non-pathogens. The majority of these families were selectively maintained in pathogenic lineages, but disappeared in non-pathogens. Non-pathogen-specific losses largely outnumbered pathogen-specific losses. Conclusions We conclude that most of the proteins for pathogenicity were already present in the ancestor of the Ascomycete lineages we used in our study. Species that did not develop pathogenicity seemed to have reduced their genetic complexity compared to their ancestors. We further show that expansion of gained or already existing families in a species-specific way is important to fine-tune the specificities of the pathogenic host-fungus interaction. PMID:20964831

2010-01-01

173

Molecular cloning and characterizations of porcine SAMHD1 and its roles in replication of highly pathogenic porcine reproductive and respiratory syndrome virus.  

PubMed

The sterile alpha motif and HD domain 1 (SAMHD1) protein is a novel innate immunity restriction factor that inhibits HIV-1 infection in myeloid cells. Here, we cloned the full-length SAMHD1 complementary DNA (cDNA) from porcine peripheral blood lymphocytes. The porcine SAMHD1 cDNA was of 3951?bp with an open reading frame of 1884?bp, encoding a polypeptide of 627 amino acids. Porcine SAMHD1 mRNA was detected in all swine tissues examined, with the higher expression in the tonsil, lung, liver, and lymph node tissues. The SAMHD1 protein was localized to the nucleus. Overexpression of SAMHD1 blocked the proliferation of HuN4, a highly pathogenic strain of porcine reproductive and respiratory syndrome virus (HP-PRRSV), in MARC-145 cells, by inhibiting the synthesis of the HuN4 complement RNA. The antiviral effects of the simian SAMHD1 protein were nearly equivalent to those of porcine SAMHD1 in the HuN4-infected MARC-145 cells. Phosphorylation analysis of SAMHD1 showed that overexpressed SAMHD1 protein was in primarily an unphosphorylated state. SAMHD1 overexpression increased the transcript abundance of IFN-stimulated genes ISG15 and ISG56. The mRNA levels of SAMHD1 and ISGs were significantly increased in porcine alveolar macrophages infected with HP-PRRSV. SAMHD1 protein level was also elevated, and the protein was not phosphorylated during infection. Collectively, our data indicate that SAMHDI inhibits HP-PRRSV proliferation through inhibiting the replication of HP-PRRSV. SAMHD1 might be the protein participating in the IFN signaling and is thus an important immunoregulatory protein in innate immunity. PMID:25106914

Yang, Shen; Shan, Tongling; Zhou, Yanjun; Jiang, Yifeng; Tong, Wu; Liu, Fei; Wen, Feng; Zhang, Qingzhan; Tong, Guangzhi

2014-12-01

174

DNA-based methodologies for rapid detection, quantification, and species- or strain-level identification of respiratory pathogens (Mycobacteria and Pseudomonads) in metalworking fluids.  

PubMed

Mycobacteria and pseudomonads occurring in modern metalworking fluids (MWF) have been implicated in occupational health hazards as causal agents for hypersensitivity pneumonitis (HP) and other respiratory illnesses in machine workers exposed to these fluids and their aerosols. Unlike the conventional cultural and biochemical methods, which are often slow and ambiguous and detect only culturable cells, DNA-based methods offer a time-saving alternative for reliable detection and identification of both culturable and nonculturable bacteria in MWF and for selective quantification of individual genera of pathogens of interest in these fluids. This is the first report on DNA-based direct detection of mycobacteria and pseudomonads in MWF without culturing. Genus-specific PCR approach was successfully applied for screening of field MWF samples originating from different industrial users for detection of mycobacteria or pseudomonads including both culturable and nonculturable cells. PCR in combination with amplicon DNA sequencing led to the identification of Mycobacterium chelonae, Pseudomonas nitroreducens, and an undefined Pseudomonas species from these fluids. Genome fingerprinting by pulsed-field gel electrophoresis (PFGE) on Mycobacterium isolates further showed that the isolates represented three strains of M. chelonae although the possibility of one of the strains being clonal with M. immunogenum cannot be excluded. In parallel efforts, a quantitative competitive PCR method developed based on the Pseudomonas-specific PCR was applied to quantify total P. fluorescens cells in contaminated metalworking fluid and MWF aerosol without culturing. The DNA-based protocols developed in this study will allow rapid screening of field MWF samples for the presence of both culturable and nonculturable cells and thus facilitate effective fluid management and timely exposure assessment. PMID:14555451

Yadav, Jagjit S; Khan, Izhar U H; Fakhari, Farnaz; Soellner, Mathew B

2003-11-01

175

Antibacterial activity and mechanism of action of Monarda punctata essential oil and its main components against common bacterial pathogens in respiratory tract  

PubMed Central

The aim of the current research work was to study the chemical composition of the essential oil of Monarda punctata along with evaluating the essential oil and its major components for their antibacterial effects against some frequently encountered respiratory infection causing pathogens. Gas chromatographic mass spectrometric analysis revealed the presence of 13 chemical constituents with thymol (75.2%), p-cymene (6.7%), limonene (5.4), and carvacrol (3.5%) as the major constituents. The oil composition was dominated by the oxygenated monoterpenes. Antibacterial activity of the essential oil and its major constituents (thymol, p-cymene, limonene) was evaluated against Streptococcus pyogenes, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae, Haemophilus influenzae and Escherichia coli. The study revealed that the essential oil and its constituents exhibited a broad spectrum and variable degree of antibacterial activity against different strains. Among the tested strains, Streptococcus pyogenes, Escherichia coli and Streptococcus pneumoniae were the most susceptible bacterial strain showing lowest MIC and MBC values. Methicillin-resistant Staphylococcus aureus was the most resistant bacterial strain to the essential oil treatment showing relatively higher MIC and MBC values. Scanning electron microscopy revealed that the essential oil induced potent and dose-dependent membrane damage in S. pyogenes and MRSA bacterial strains. The reactive oxygen species generated by the Monarda punctata essential oil were identified using 2’, 7’-dichlorofluorescein diacetate (DCFDA).This study indicated that the Monarda punctata essential oil to a great extent and thymol to a lower extent triggered a substantial increase in the ROS levels in S. pyogenes bacterial cultures which ultimately cause membrane damage as revealed by SEM results.

Li, Hong; Yang, Tian; Li, Fei-Yan; Yao, Yan; Sun, Zhong-Min

2014-01-01

176

Survival of Potentially Pathogenic Human-Associated Bacteria in the Rhizosphere of Hydroponically Grown Wheat  

NASA Technical Reports Server (NTRS)

Plants may serve as reservoirs for human-associated bacteria (H-AB) in long-term space missions containing bioregenerative life support systems. The current study examined the abilities of five human-associated potential pathogens, Pseudomonas aeruginosa, Pseudomonas cepacia, Staphylococcus aureus, Streptococcus pyogenes, and Escherichia coli, to colonize and grow in the rhizosphere of hydroponically grown wheat, a candidate crop for life support. All of these bacteria have been recovered from past NASA missions and present potential problems for future missions. The abilities of these organisms to adhere to the roots of axenic five-day-old wheat (Triticum aestivum L. cv. Yecora rojo) were evaluated by enumeration of the attached organisms after a one hour incubation of roots in a suspension (approximately 10(exp 8 cu/ml)) of the H-AB. Results showed that a greater percentage of P. aeruginosa cells adhered to the wheat roots than the other four H-AB. Similarly incubated seedlings were also grown under attempted axenic conditions for seven days to examine the potential of each organism to proliferate in the rhizosphere (root colonization capacity). P. cepacia and P. aeruginosa showed considerable growth. E. coli and S. aureus showed no significant growth, and S. pyogenes died off in the wheat rhizosphere. Studies examining the effects of competition on the survival of these microorganisms indicated that P. aeruginosa was the only organism that survived in the rhizosphere of hydroponically grown wheat in the presence of different levels of microbial competition.

Morales, Anabelle; Garland, Jay L.; Lim, Daniel V.

1996-01-01

177

Characterisation of acute respiratory infections at a United Kingdom paediatric teaching hospital: observational study assessing the impact of influenza A (2009 pdmH1N1) on predominant viral pathogens  

PubMed Central

Background According to the World Health Organisation, influenza A (2009 pdmH1N1) has moved into the post-pandemic phase, but there were still high numbers of infections occurring in the United Kingdom in 2010-11. It is therefore important to examine the burden of acute respiratory infections at a large children’s hospital to determine pathogen prevalence, occurrence of co-infection, prevalence of co-morbidities and diagnostic yield of sampling methods. Methods This was a retrospective study of respiratory virus aetiology in acute admissions to a paediatric teaching hospital in the North West of England between 1st April 2010 and 31st March 2011. Respiratory samples were analysed either with a rapid RSV test if the patient had symptoms suggestive of bronchiolitis, followed by multiplex PCR testing for ten respiratory viruses, or with multiplex PCR testing alone if the patient had suspected other ARI. Patient demographics and data regarding severity of illness, presence of co-morbidities and respiratory virus sampling method were retrieved from case notes. Results 645 patients were admitted during the study period. 82/645 (12.7%) patients were positive for 2009 pdmH1N1, of whom 24 (29.2%) required PICU admission, with 7.3% mortality rate. Viral co-infection occurred in 48/645 (7.4%) patients and was not associated with more severe disease. Co-morbidities were present more frequently in older children, but there was no significant difference in prevalence of co-morbidity between 2009 pdmH1N1 patients and those with other ARI. NPA samples had the highest diagnostic yield with 192/210 (91.4%) samples yielding an organism. Conclusions Influenza A (2009 pdmH1N1) is an ongoing cause of occasionally severe disease affecting both healthy children and those with co-morbidities. Surveillance of viral pathogens provides valuable information on patterns of disease. PMID:24948099

2014-01-01

178

Absence of a set of plasmid-encoded genes is predictive of reduced pathogenic potential in Brachyspira hyodysenteriae.  

PubMed

The gene content of 14 strains of the intestinal spirochaete Brachyspira hyodysenteriae was compared using a DNA microarray. A consistent difference occurred in a block of four genes on the ~36 Kb plasmid, with these being present in six virulent strains and absent in eight strains with reduced pathogenic potential. These genes encoded a predicted radical S-adenosylmethionine domain protein, a glycosyl transferase group 1-like protein, an NAD dependent epimerase and a dTDP-4-dehydrorhamnose 2-5 epimerase: they may be involved in rhamnose biosynthesis and glycosylation. The absence of these plasmid genes in B. hyodysenteriae isolates is predictive of reduced pathogenic potential. PMID:25512147

La, Tom; Phillips, Nyree D; Thomson, Jill R; Hampson, David J

2014-01-01

179

"Features of two proteins of Leptospira interrogans with potential role in host-pathogen interactions"  

PubMed Central

Background Leptospirosis is considered a re-emerging infectious disease caused by pathogenic spirochaetes of the genus Leptospira. Pathogenic leptospires have the ability to survive and disseminate to multiple organs after penetrating the host. Leptospires were shown to express surface proteins that interact with the extracellular matrix (ECM) and to plasminogen (PLG). This study examined the interaction of two putative leptospiral proteins with laminin, collagen Type I, collagen Type IV, cellular fibronectin, plasma fibronectin, PLG, factor H and C4bp. Results We show that two leptospiral proteins encoded by LIC11834 and LIC12253 genes interact with laminin in a dose - dependent and saturable mode, with dissociation equilibrium constants (KD) of 367.5 and 415.4 nM, respectively. These proteins were named Lsa33 and Lsa25 (Leptospiral surface adhesin) for LIC11834 and LIC12253, respectively. Metaperiodate - treated laminin reduced Lsa25 - laminin interaction, suggesting that sugar moieties of this ligand participate in this interaction. The Lsa33 is also PLG - binding receptor, with a KD of 23.53 nM, capable of generating plasmin in the presence of an activator. Although in a weak manner, both proteins interact with C4bp, a regulator of complement classical route. In silico analysis together with proteinase K and immunoflorescence data suggest that these proteins might be surface exposed. Moreover, the recombinant proteins partially inhibited leptospiral adherence to immobilized laminin and PLG. Conclusions We believe that these multifunctional proteins have the potential to participate in the interaction of leptospires to hosts by mediating adhesion and by helping the bacteria to escape the immune system and to overcome tissue barriers. To our knowledge, Lsa33 is the first leptospiral protein described to date with the capability of binding laminin, PLG and C4bp in vitro. PMID:22463075

2012-01-01

180

Potential oversummering and overwintering regions for the wheat stripe rust pathogen in the contiguous United States  

NASA Astrophysics Data System (ADS)

Epidemics of wheat stripe rust, caused by Puccinia striiformis f. sp. tritici ( Pst), are more frequent in the regions where Pst can oversummer and overwinter. Regions for potential oversummering and overwintering of Pst were determined in the contiguous United States using a survival index (SI) ranging from 0 (most unfavorable) to 10 (most favorable) developed based on long-term weather data. The pathogen can survive in cool summer in the most regions north of latitude 40°N, particularly Washington, Idaho, Montana, Oregon and California. Due to limiting high temperatures, it survives marginally during summer in Arkansas, Delaware, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Massachusetts, Missouri, Ohio, Oklahoma, Rhode Island and Texas. Similarly, unfavorable hot summer restricts summer survival of the pathogen in the most regions south of 40°N except for highlands in the Rocky or Appalachian Mountains. Warm winters favor fungal survival in most regions south of 40°N and the Pacific Coast, including Alabama, Arkansas, Arizona, California, Florida, Georgia, Idaho, Louisiana, Mississippi, New Mexico, Nevada, Oregon, South Carolina, Texas and Washington. Severe winters do not allow survival in most regions north of 40°N and east of the Rocky Mountains, whereas less severe winter in Delaware, Illinois, Indiana, Kansas, Kentucky, Massachusetts, Maryland, Michigan, Missouri, North Carolina, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, Tennessee, Utah and Virginia permits marginal survival of Pst. Most wheat-growing regions have climatic suitability for either oversummering or overwintering. Both oversummering and overwintering can occur in the Pacific Northwest (Idaho, Oregon and Washington), Arizona, California, North Carolina, New Mexico, Pennsylvania, Virginia and West Virginia. These regions may provide primary inoculum for stripe rust epidemics in their own and surrounding regions.

Sharma-Poudyal, Dipak; Chen, Xianming; Rupp, Richard Alan

2014-07-01

181

Infected or not: are PCR-positive oropharyngeal swabs indicative of low pathogenic influenza A virus infection in the respiratory tract of Mallard Anas platyrhynchos?  

PubMed

Detection of influenza virus in oropharyngeal swabs collected during wild bird surveillance is assumed to represent respiratory infection, although intestine is the main site of infection. We tested this assumption by histological examination of the respiratory tract of wild Mallards with virus-positive oropharyngeal swabs. Thirty-two of 125 Mallards tested had viral-RNA positive oropharyngeal swabs. The respiratory tracts of four Mallards with the most virus were examined in detail by immunohistochemistry. None had detectable virus antigen in the respiratory tract, suggesting it was not infected. An alternative explanation is that the oropharynx was contaminated with virus through feeding in surface water or through preening. PMID:24885647

Wille, Michelle; van Run, Peter; Waldenström, Jonas; Kuiken, Thijs

2014-01-01

182

Present-day potentialities of endoscopic diagnostics and treatment of early cancer in respiratory and digestive tracts  

NASA Astrophysics Data System (ADS)

The paper presents the latest potentialities of the endoscopic fluorescent diagnostics as well as endoscopic electric-, laser surgery and photodynamic therapy (PDT) of the early cancer in the respiratory and digestive tracts. We present in detail indication and factors determining the application of the endoscopic resection of the tumor. The advantages of the combination application of PDT, electro-, Nd:YAG laser surgery and brachitherapy are stressed. The near and remote results of endoscopic treatment of the early cancer in larynx (37), lung (109), esophagus (39) and stomach (58) are shown.

Sokolov, Victor V.; Zharkova, Natalia N.; Filonenko, E. V.; Telegina, L. V.; Karpova, E. S.

1999-12-01

183

Tick capillary feeding for the study of proteins involved in tick-pathogen interactions as potential antigens for the control of tick infestation and pathogen infection  

PubMed Central

Background Ticks represent a significant health risk to animals and humans due to the variety of pathogens they can transmit during feeding. The traditional use of chemicals to control ticks has serious drawbacks, including the selection of acaricide-resistant ticks and environmental contamination with chemical residues. Vaccination with the tick midgut antigen BM86 was shown to be a good alternative for cattle tick control. However, results vary considerably between tick species and geographic location. Therefore, new antigens are required for the development of vaccines controlling both tick infestations and pathogen infection/transmission. Tick proteins involved in tick-pathogen interactions may provide good candidate protective antigens for these vaccines, but appropriate screening procedures are needed to select the best candidates. Methods In this study, we selected proteins involved in tick-Anaplasma (Subolesin and SILK) and tick-Babesia (TROSPA) interactions and used in vitro capillary feeding to characterize their potential as antigens for the control of cattle tick infestations and infection with Anaplasma marginale and Babesia bigemina. Purified rabbit polyclonal antibodies were generated against recombinant SUB, SILK and TROSPA and added to uninfected or infected bovine blood to capillary-feed female Rhipicephalus (Boophilus) microplus ticks. Tick weight, oviposition and pathogen DNA levels were determined in treated and control ticks. Results The specificity of purified rabbit polyclonal antibodies against tick recombinant proteins was confirmed by Western blot and against native proteins in tick cell lines and tick tissues using immunofluorescence. Capillary-fed ticks ingested antibodies added to the blood meal and the effect of these antibodies on tick weight and oviposition was shown. However, no effect was observed on pathogen DNA levels. Conclusions These results highlighted the advantages and some of the disadvantages of in vitro tick capillary feeding for the characterization of candidate tick protective antigens. While an effect on tick weight and oviposition was observed, the effect on pathogen levels was not evident probably due to high tick-to-tick variations among other factors. Nevertheless, these results together with previous results of RNA interference functional studies suggest that these proteins are good candidate vaccine antigens for the control of R. microplus infestations and infection with A. marginale and B. bigemina. PMID:24450836

2014-01-01

184

Assessment of Pathogenic Potential of Avian Influenza Viruses by MDCK Cell Culture  

Microsoft Academic Search

4 Abstract: The influenza viruses are sub-classified in to two pathotypes of Highly Pathogenic Avian Influenza (HPAI) and Low Pathogenic Avian Influenza (LPAI) viruses on the basis of the pathogenicity of AIV in domestic poultry. Samples of H5N1 (7966\\/06 and 7972\\/06) and the H9N1 (5844\\/05) viruses were also grown on MDCK cell. All these produced cytopathic effect within 72 h.

B. P. Shankar; R. N. Sreenivas; B. Pattnaik; B. H. Manjunatha; R. P. Kamal; B. K. Sreenivas; H. S. Madhusudhan; D. Ranjith; H. K. Pradhan

2009-01-01

185

Respiratory acidosis  

MedlinePLUS

Ventilatory failure; Respiratory failure; Acidosis - respiratory ... Causes of respiratory acidosis include: Diseases of the airways (such as asthma and chronic obstructive lung disease ) Diseases of the chest ( ...

186

Inhibition of Airway Na+ Transport by Respiratory Syncytial Virus  

Microsoft Academic Search

In previous studies, we have shown that two major respiratory pathogens, influenza virus and parainfluenza virus, produce acute alterations in ion transport upon contacting the apical membrane of the respiratory epithelium. In the present study, we examine the effects on ion transport by the mouse tracheal epithelium of a third major respiratory pathogen, respiratory syncytial virus (RSV). RSV infections are

Karl Kunzelmann; Jane Sun; Jayesh Meanger; Nicholas J. King; David I. Cook

2007-01-01

187

Neoplastic and potentially prenoeplastic changes in the upper respiratory tract of rats and mice.  

PubMed Central

The National Toxicology Program (NTP) database was examined for tumor incidences and chemicals producing tumors in the nasal cavity, larynx, or trachea. Slides from appropriate studies were then examined in an attempt to unify terminology and make comparisons between induced and spontaneous tumors and hyperplastic or preneoplastic lesions produced in the upper respiratory system. An attempt was also made to compare the species affected, route of administration, and tumor types produced by different chemicals. The results are not meant to be all inclusive of the NTP database but to be representative of observed trends. General conclusions that emerged from this review were that rats are much more susceptible to epithelial tumors of the nasal cavity than mice; that only mice have been reported to have chemically induced hemangiomas and hemangiosarcomas of the nasal cavity; that tumors of the olfactory epithelium and squamous cell tumors of the respiratory epithelium are almost uniformly malignant and invasive, while other tumors of the respiratory epithelium are typically less invasive; that most chemically induced tumors of the olfactory region, either mesenchymal or epithelial, do not require an inhalation route of exposure but appear to occur by systemic targeting of this region; and that a uniform nomenclature for tumors of the nasal cavity is needed. Images PLATE 1. PLATE 2. PLATE 3. A PLATE 3. B PLATE 3. C PLATE 4. A PLATE 4. B PLATE 5. A PLATE 5. B PLATE 6. A PLATE 6. B PLATE 7. PLATE 8. A PLATE 8. B PLATE 8. C PLATE 9. PLATE 10. A PLATE 10. B PLATE 11. PLATE 12. PLATE 13. PLATE 14. PLATE 15. PLATE 16. PLATE 17. PLATE 18. A PLATE 18. B PLATE 19. A PLATE 19. B PMID:2384063

Brown, H R

1990-01-01

188

The pathogenic potential of the Lichtheimia genus revisited: Lichtheimia brasiliensis is a novel, non-pathogenic species.  

PubMed

Lichtheimia brasiliensis was recently described as a novel species within the genus Lichtheimia, which comprises a total of six species. L. brasiliensis was first reported from soil in Brazil. The aim of the study was to determine the relative virulence potential of L. brasiliensis using an avian infection model based on chicken embryos. PMID:25267009

Schwartze, Volker U; de A Santiago, André Luiz C M; Jacobsen, Ilse D; Voigt, Kerstin

2014-12-01

189

Potential for bio-control of food-borne pathogens with Bacteriovorax spp. and implications for food safety  

Technology Transfer Automated Retrieval System (TEKTRAN)

Bacteriovorax spp. (Bvx) are delta proteobacteria adapted to marine ecosystems where salinity concentration range from 1-3%. Due to their predation of Gram-negative bacteria, Bvx may have great potential for biocontrol of food-borne pathogens on fruits and leafy greens. The goal of this research was...

190

Antibacterial activity and mode of action of the Artemisia capillaris essential oil and its constituents against respiratory tract infection-causing pathogens.  

PubMed

Inhalation therapy using essential oils has been used to treat acute and chronic sinusitis and bronchitis. The aim of the present study was to determine the chemical composition of the essential oil of Artemisia capillaris, and evaluate the antibacterial effects of the essential oil and its main components, against common clinically relevant respiratory bacterial pathogens. Gas chromatography and gas chromatography?mass spectrometry revealed the presence of 25 chemical constituents, the main constituents being: ??pinene, ??pinene, limonene, 1,8?cineole, piperitone, ??caryophyllene and capillin. The antibacterial activities of the essential oil, and its major constituents, were evaluated against Streptococcus pyogenes, methicillin?resistant Staphylococcus aureus (MRSA), MRSA (clinical strain), methicillin?gentamicin resistant Staphylococcus aureus (MGRSA), Streptococcus pneumoniae, Klebsiella pneumoniae, Haemophilus influenzae and Escherichia coli. The essential oil and its constituents exhibited a broad spectrum and variable degree of antibacterial activity against the various strains. The essential oil was observed to be much more potent, as compared with any of its major chemical constituents, exhibiting low minimum inhibitory and bacteriocidal concentration values against all of the bacterial strains. The essential oil was most active against S. pyogenes, MRSA (clinical strain), S. pneumoniae, K. pneumoniae, H. influenzae and E. coli. Piperitone and capillin were the most potent growth inhibitors, among the major chemical constituents. Furthermore, the essential oil of A. capillaris induced significant and dose?dependent morphological changes in the S. aureus bacterial strain, killing >90% of the bacteria when administered at a higher dose; as determined by scanning electron microscopy. In addition, the essential oil induced a significant leakage of potassium and phosphate ions from the S. aureus bacterial cultures. These results indicate that the antibacterial action of A. capillaris essential oil may be mediated through the leakage of these two important ions. In conclusion, A. capillaris essential oil exhibits potent antibacterial activity by inducing morphological changes and leakage of ions in S. aureus bacterial cultures. PMID:25522803

Yang, Chang; Hu, Dong-Hui; Feng, Yan

2015-04-01

191

The Pathogens of Diamondback Moth and Their Potential for its Control a Review  

Microsoft Academic Search

The larvae and less frequently the pupae of Plutella xylostella (L) are sometimes attacked naturally by pathogens, particularly two fungi of the family Entomophthoraceae, Erynia blunckii and Zoophthora radicans. Other pathogens recorded include one other entomophthoraceous fungus, a granulosis virus, one or possibly two nucleopolyhedrosis viruses and Bacillus thuringiensis var kurstaki. In the laboratory, larvae were also susceptible to strains

Neil Wilding

192

Adaptive potential of ash (Fraxinus excelsior) populations against the novel emerging pathogen Hymenoscyphus pseudoalbidus.  

PubMed

An emerging infectious pathogen Hymenoscyphus pseudoalbidus has spread across much of Europe within recent years causing devastating damage on European common ash trees (Fraxinus excelsior) and associated plant communities. The present study demonstrates the presence of additive genetic variation in susceptibility of natural F. excelsior populations to the new invasive disease. We observe high levels of additive variation in the degree of susceptibility with relatively low influence of environmental factors (narrow-sense heritability = 0.37-0.52). Most native trees are found to be highly susceptible, and we estimate that only around 1% has the potential of producing offspring with expected crown damage of <10% under the present disease pressure. The results suggest that the presence of additive genetic diversity in natural F. excelsior populations can confer the species with important ability to recover, but that low resistance within natural European populations is to be expected because of a low frequency of the hypo-sensitive trees. Large effective population sizes will be required to avoid genetic bottlenecks. The role of artificial selection and breeding for protection of the species is discussed based on the findings. PMID:25568043

Kjær, Erik Dahl; McKinney, Lea Vig; Nielsen, Lene Rostgaard; Hansen, Lars Nørgaard; Hansen, Jon Kehlet

2012-04-01

193

Occurrence of potentially pathogenic nontuberculous mycobacteria in Mexican household potable water: a pilot study  

PubMed Central

Background Nontuberculous mycobacteria (NTM) are environmental opportunistic pathogens found in natural and human-engineered waters, including drinking water distribution systems and household plumbing. This pilot study examined the frequency of occurrence of NTM in household potable water samples in Mexico City. Potable water samples were collected from the “main house faucet” and kitchen faucet. The presence of aerobic-mesophilic bacteria (AMB), total coliforms (TC), fecal coliforms (FC) and NTM species were determined. Mycobacteria species were identified by PCR restriction enzyme pattern analysis (PRA) of the 65-kDa heat shock protein gene (hsp65) and sequencing of the hypervariable region 2 (V2) of the 16S rRNA gene and of the rpoB gene. Results AMB (<100 CFU/ml) were present in 118 out of 120 samples; only two samples were outside guidelines ranges (>100 CFU/ml). TC and FC were detected in four and one samples, respectively. NTM species were recovered from 16% samples (19/120) and included M. mucogenicum (nine), M. porcinum (three), M. avium (three), M. gordonae (one), M. cosmeticum (one), M. fortuitum (one), and Mycobacterium sp (one). All household water samples that contained NTM complied with the standards required to grade the water as “good quality” potable water. Conclusion Household potable water may be a potential source of NTM infection in Mexico City. PMID:24330835

2013-01-01

194

Adaptive potential of ash (Fraxinus excelsior) populations against the novel emerging pathogen Hymenoscyphus pseudoalbidus  

PubMed Central

An emerging infectious pathogen Hymenoscyphus pseudoalbidus has spread across much of Europe within recent years causing devastating damage on European common ash trees (Fraxinus excelsior) and associated plant communities. The present study demonstrates the presence of additive genetic variation in susceptibility of natural F. excelsior populations to the new invasive disease. We observe high levels of additive variation in the degree of susceptibility with relatively low influence of environmental factors (narrow-sense heritability = 0.37–0.52). Most native trees are found to be highly susceptible, and we estimate that only around 1% has the potential of producing offspring with expected crown damage of <10% under the present disease pressure. The results suggest that the presence of additive genetic diversity in natural F. excelsior populations can confer the species with important ability to recover, but that low resistance within natural European populations is to be expected because of a low frequency of the hypo-sensitive trees. Large effective population sizes will be required to avoid genetic bottlenecks. The role of artificial selection and breeding for protection of the species is discussed based on the findings.

Kjær, Erik Dahl; McKinney, Lea Vig; Nielsen, Lene Rostgaard; Hansen, Lars Nørgaard; Hansen, Jon Kehlet

2012-01-01

195

Antimicrobial potential of Ricinus communis leaf extracts in different solvents against pathogenic bacterial and fungal strains  

PubMed Central

Objective To investigate the in vitro antimicrobial activities of the leaf extract in different solvents viz., methanol, ethanol and water extracts of the selected plant Ricinus communis. Methods Agar well diffusion method and agar tube dilution method were carried out to perform the antibacterial and antifungal activity of methanol, ethanol and aqueous extracts. Results Methanol leaf extracts were found to be more active against Gram positive bacteria (Bacillus subtilis: ATCC 6059 and Staphylococcus aureus: ATCC 6538) as well as Gram negative bacteria (Pseudomonas aeruginosa: ATCC 7221 and Klebsiella pneumoniae) than ethanol and aqueous leaf extracts. Antifungal activity of methanol and aqueous leaf extracts were also carried out against selected fungal strains as Aspergillus fumigatus and Aspergillus flavus. Methanolic as well as aqueous leaf extracts of Ricinus communis were effective in inhibiting the fungal growth. Conclusions The efficient antibacterial and antifungal activity of Ricinus communis from the present investigation revealed that the methanol leaf extracts of the selected plant have significant potential to inhibit the growth of pathogenic bacterial and fungal strains than ethanol and aqueous leaf extracts. PMID:23593573

Naz, Rabia; Bano, Asghari

2012-01-01

196

Oscillatory behavior of ventricular action potential duration in heart failure patients at respiratory rate and low frequency  

PubMed Central

Oscillations of arterial pressure occur spontaneously at a frequency of approximately 0.1 Hz coupled with synchronous oscillations of sympathetic nerve activity (“Mayer waves”). This study investigated the extent to which corresponding oscillations may occur in ventricular action potential duration (APD). Fourteen ambulatory (outpatient) heart failure patients with biventricular pacing devices were studied while seated upright watching movie clips to maintain arousal. Activation recovery intervals (ARI) as a measure of ventricular APD were obtained from unipolar electrograms recorded from the LV epicardial pacing lead during steady state RV pacing from the device. Arterial blood pressure was measured non-invasively (Finapress) and respiration monitored. Oscillations were quantified using time frequency and coherence analysis. Oscillatory behavior of ARI at the respiratory frequency was observed in all subjects. The magnitude of the ARI variation ranged from 2.2 to 6.9 ms (mean 5.0 ms). Coherence analysis showed a correlation with respiratory oscillation for an average of 43% of the recording time at a significance level of p < 0.05. Oscillations in systolic blood pressure in the Mayer wave frequency range were observed in all subjects for whom blood pressure was recorded (n = 13). ARI oscillation in the Mayer wave frequency range was observed in 6/13 subjects (46%) over a range of 2.9 to 9.2 ms. Coherence with Mayer waves at the p < 0.05 significance level was present for an average of 29% of the recording time. In ambulatory patients with heart failure during enhanced mental arousal, left ventricular epicardial APD (ARI) oscillated at the respiratory frequency (approximately 0.25 Hz). In 6 patients (46%) APD oscillated at the slower Mayer wave frequency (approximately 0.1 Hz). These findings may be important in understanding sympathetic activity-related arrhythmogenesis. PMID:25389408

Hanson, Ben; Child, Nick; Van Duijvenboden, Stefan; Orini, Michele; Chen, Zhong; Coronel, Ruben; Rinaldi, Christopher A.; Gill, Jaspal S.; Gill, Jaswinder S.; Taggart, Peter

2014-01-01

197

Genomic Target Database (GTD): A database of potential targets in human pathogenic bacteria  

PubMed Central

A Genomic Target Database (GTD) has been developed having putative genomic drug targets for human bacterial pathogens. The selected pathogens are either drug resistant or vaccines are yet to be developed against them. The drug targets have been identified using subtractive genomics approaches and these are subsequently classified into Drug targets in pathogen specific unique metabolic pathways,Drug targets in host-pathogen common metabolic pathways, andMembrane localized drug targets. HTML code is used to link each target to its various properties and other available public resources. Essential resources and tools for subtractive genomic analysis, sub-cellular localization, vaccine and drug designing are also mentioned. To the best of authors knowledge, no such database (DB) is presently available that has listed metabolic pathways and membrane specific genomic drug targets based on subtractive genomics. Listed targets in GTD are readily available resource in developing drug and vaccine against the respective pathogen, its subtypes, and other family members. Currently GTD contains 58 drug targets for four pathogens. Shortly, drug targets for six more pathogens will be listed. Availability GTD is available at IIOAB website http://www.iioab.webs.com/GTD.htm. It can also be accessed at http://www.iioabdgd.webs.com.GTD is free for academic research and non-commercial use only. Commercial use is strictly prohibited without prior permission from IIOAB. PMID:20011153

Barh, Debmalya; Kumar, Anil; Misra, Amarendra Narayana

2009-01-01

198

Potential role of porcine reproductive and respiratory syndrome virus structural protein GP2 in apoptosis inhibition.  

PubMed

Porcine reproductive and respiratory syndrome virus (PRRSV) is a serious threat to the pork industry, and its pathogenesis needs further investigations. To study the role of two structural proteins of PRRSV in virus-host cells interactions, two stable cell lines (MARC-2a and MARC-N) expressing GP2 and N proteins, respectively, were established. We induced apoptosis in these cells by treating them with staurosporine and found a significant reduction in the number of apoptotic cells in MARC-2a as compared to MARC-N and MARC-145 cells. In addition, we found significantly higher activities of transcriptional factors (NF- ? B and AP-1) in both cell lines as compared to MARC-145 (parent cells). Overall, our data suggest that, although both stable cell lines activate NF- ? B and AP-1, GP2 triggers the antiapoptotic process through an intermediate step that needs to be further investigated. PMID:24511529

Pujhari, Sujit; Baig, Tayyba T; Zakhartchouk, Alexander N

2014-01-01

199

Potential Role of Porcine Reproductive and Respiratory Syndrome Virus Structural Protein GP2 in Apoptosis Inhibition  

PubMed Central

Porcine reproductive and respiratory syndrome virus (PRRSV) is a serious threat to the pork industry, and its pathogenesis needs further investigations. To study the role of two structural proteins of PRRSV in virus-host cells interactions, two stable cell lines (MARC-2a and MARC-N) expressing GP2 and N proteins, respectively, were established. We induced apoptosis in these cells by treating them with staurosporine and found a significant reduction in the number of apoptotic cells in MARC-2a as compared to MARC-N and MARC-145 cells. In addition, we found significantly higher activities of transcriptional factors (NF-?B and AP-1) in both cell lines as compared to MARC-145 (parent cells). Overall, our data suggest that, although both stable cell lines activate NF-?B and AP-1, GP2 triggers the antiapoptotic process through an intermediate step that needs to be further investigated. PMID:24511529

Pujhari, Sujit; Baig, Tayyba T.; Zakhartchouk, Alexander N.

2014-01-01

200

Antifungal substances produced by Penicillium oxalicum strain PY1—potential antibiotics against plant pathogenic fungi  

Microsoft Academic Search

This paper reports the isolation from soil of Penicillium strain PY-1 with strong antagonistic activity against plant pathogenic fungi. On the basis of its morphological characteristics\\u000a and the sequence of the ITS region, strain PY-1 was identified as P. oxalicum. Strain PY-1 produces antifungal substances that suppress the mycelial growth of Sclerotinia sclerotiorum and many other plant pathogenic fungi tested;

Liping Yang; Jiatao Xie; Daohong Jiang; Yanping Fu; Guoqing Li; Fangcan Lin

2008-01-01

201

Components of Pathogenic Leptospira spp. with Potentials for Diagnosis of Human Leptospirosis  

Microsoft Academic Search

SUMMARY Existing serological methods for diagnosis of leptospirosis are still unsatisfactorily due mainly to their low accuracy. In this study, serum samples of 18 clinically diagnosed-, IgM dipstick positive-, MAT positive- leptospirosis patients (group 1) were analyzed by IgG Western blotting against SDS-PAGE separated-whole cell homogenates of pathogenic and non-pathogenic Leptospira spp. belonging to 20 serovars of 15 serogroups. The

Patcharin Saengjaruk; Yuwaporn Sakolvaree; Kanchana Tomanakan; Pongsri Tongtawe; Pramaun Tapchaisri; Wanpen Chaicumpa

202

Bacteriophages with Potential for Inactivation of Fish Pathogenic Bacteria: Survival, Host Specificity and Effect on Bacterial Community Structure  

PubMed Central

Phage therapy may represent a viable alternative to antibiotics to inactivate fish pathogenic bacteria. Its use, however, requires the awareness of novel kinetics phenomena not applied to conventional drug treatments. The main objective of this work was to isolate bacteriophages with potential to inactivate fish pathogenic bacteria, without major effects on the structure of natural bacterial communities of aquaculture waters. The survival was determined in marine water, through quantification by the soft agar overlay technique. The host specificity was evaluated by cross infection. The ecological impact of phage addition on the structure of the bacterial community was evaluated by DGGE of PCR amplified 16S rRNA gene fragments. The survival period varied between 12 and 91 days, with a higher viability for Aeromonas salmonicida phages. The phages of Vibrio parahaemolyticus and of A. salmonicida infected bacteria of different families with a high efficacy of plating. The specific phages of pathogenic bacteria had no detectable impact on the structure of the bacterial community. In conclusion, V. parahaemolyticus and A. salmonicida phages show good survival time in marine water, have only a moderated impact on the overall bacterial community structure and the desired specificity for host pathogenic bacteria, being potential candidates for therapy of fish infectious diseases in marine aquaculture systems. PMID:22163184

Pereira, Carla; Silva, Yolanda J.; Santos, Ana L.; Cunha, Ângela; Gomes, Newton C. M.; Almeida, Adelaide

2011-01-01

203

Molecular identification of potential pathogens in water and air of a hospital therapy pool  

PubMed Central

Indoor warm-water therapy pool workers in a Midwestern regional hospital were diagnosed with non-tuberculosis pulmonary hypersensitive pneumonitis and Mycobacterium avium infections. In response, we conducted a multiseason survey of microorganisms present in this therapy pool water, in biofilms associated with the pool containment walls, and in air immediately above the pool. The survey used culture, microscopy, and culture-independent molecular phylogenetic analyses. Although outfitted with a state-of-the-art UV-peroxide disinfection system, the numbers of bacteria in the therapy pool water were relatively high compared with the potable water used to fill the pool. Regardless of the source, direct microscopic counts of microbes were routinely ?1,000 times greater than conventional plate counts. Analysis of clone libraries of small subunit rRNA genes from environmental DNA provided phylogenetic diversity estimates of the microorganisms collected in and above the pool. A survey of >1,300 rRNA genes yielded a total of 628 unique sequences, the most common of which was nearly identical to that of M. avium strains. The high proportion of clones with different Mycobacterium spp. rRNA genes suggested that such organisms comprised a significant fraction of microbes in the pool water (to >30%) and preferentially partition into aerosols (to >80%) relative to other waterborne bacteria present. The results of the study strongly validate aerosol partitioning as a mechanism for disease transfer in these environments. The results also show that culture protocols currently used by public health facilities and agencies are seriously inadequate for the detection and enumeration of potential pathogens. PMID:15769858

Angenent, Largus T.; Kelley, Scott T.; Amand, Allison St.; Pace, Norman R.; Hernandez, Mark T.

2005-01-01

204

A Comparative Study of Metabolic Network Topology between a Pathogenic and a Non-Pathogenic Bacterium for Potential Drug Target Identification.  

PubMed

Metabolic network provides a unified platform to integrate all the biological information on genes, proteins, metabolites, drugs and drug targets for a comprehensive system level study of the relationship between metabolism and disease. In recent times, drug-target identification by in silico methods has emerged causing a phenomenal achievement in the field of drug discovery. This paper focuses on describing how microbial drug target identification can be carried out using bioinformatic tools. Specifically, it highlights the use of metabolic 'choke point' and 'load point' analyses to understand the local and global properties of metabolic networks in Pseudomonas aeruginosa and allow us to identify potential drug targets. We also list out top 10 choke point enzymes based on the load point values and the number of shortest paths. A non-pathogenic bacterial strain Pseudomonas putida KT2440 and a related pathogenic bacteria P.aeruginosa PA01 was selected for the network anlaysis. A comparative study of the metabolic networks of these two microbes highlights the analogies and differences between their respective pathways. System analysis of metabolic networks will help us in identifying new drug targets which in turn will generate more in-depth understanding of the mechanism of diseases and thus provide better guidance for drug discovery. PMID:21347179

Perumal, Deepak; Lim, Chu Sing; Sakharkar, Meena K

2009-01-01

205

Distinctive expansion of potential virulence genes in the genome of the oomycete fish pathogen Saprolegnia parasitica.  

PubMed

Oomycetes in the class Saprolegniomycetidae of the Eukaryotic kingdom Stramenopila have evolved as severe pathogens of amphibians, crustaceans, fish and insects, resulting in major losses in aquaculture and damage to aquatic ecosystems. We have sequenced the 63 Mb genome of the fresh water fish pathogen, Saprolegnia parasitica. Approximately 1/3 of the assembled genome exhibits loss of heterozygosity, indicating an efficient mechanism for revealing new variation. Comparison of S. parasitica with plant pathogenic oomycetes suggests that during evolution the host cellular environment has driven distinct patterns of gene expansion and loss in the genomes of plant and animal pathogens. S. parasitica possesses one of the largest repertoires of proteases (270) among eukaryotes that are deployed in waves at different points during infection as determined from RNA-Seq data. In contrast, despite being capable of living saprotrophically, parasitism has led to loss of inorganic nitrogen and sulfur assimilation pathways, strikingly similar to losses in obligate plant pathogenic oomycetes and fungi. The large gene families that are hallmarks of plant pathogenic oomycetes such as Phytophthora appear to be lacking in S. parasitica, including those encoding RXLR effectors, Crinkler's, and Necrosis Inducing-Like Proteins (NLP). S. parasitica also has a very large kinome of 543 kinases, 10% of which is induced upon infection. Moreover, S. parasitica encodes several genes typical of animals or animal-pathogens and lacking from other oomycetes, including disintegrins and galactose-binding lectins, whose expression and evolutionary origins implicate horizontal gene transfer in the evolution of animal pathogenesis in S. parasitica. PMID:23785293

Jiang, Rays H Y; de Bruijn, Irene; Haas, Brian J; Belmonte, Rodrigo; Löbach, Lars; Christie, James; van den Ackerveken, Guido; Bottin, Arnaud; Bulone, Vincent; Díaz-Moreno, Sara M; Dumas, Bernard; Fan, Lin; Gaulin, Elodie; Govers, Francine; Grenville-Briggs, Laura J; Horner, Neil R; Levin, Joshua Z; Mammella, Marco; Meijer, Harold J G; Morris, Paul; Nusbaum, Chad; Oome, Stan; Phillips, Andrew J; van Rooyen, David; Rzeszutek, Elzbieta; Saraiva, Marcia; Secombes, Chris J; Seidl, Michael F; Snel, Berend; Stassen, Joost H M; Sykes, Sean; Tripathy, Sucheta; van den Berg, Herbert; Vega-Arreguin, Julio C; Wawra, Stephan; Young, Sarah K; Zeng, Qiandong; Dieguez-Uribeondo, Javier; Russ, Carsten; Tyler, Brett M; van West, Pieter

2013-06-01

206

Distinctive Expansion of Potential Virulence Genes in the Genome of the Oomycete Fish Pathogen Saprolegnia parasitica  

PubMed Central

Oomycetes in the class Saprolegniomycetidae of the Eukaryotic kingdom Stramenopila have evolved as severe pathogens of amphibians, crustaceans, fish and insects, resulting in major losses in aquaculture and damage to aquatic ecosystems. We have sequenced the 63 Mb genome of the fresh water fish pathogen, Saprolegnia parasitica. Approximately 1/3 of the assembled genome exhibits loss of heterozygosity, indicating an efficient mechanism for revealing new variation. Comparison of S. parasitica with plant pathogenic oomycetes suggests that during evolution the host cellular environment has driven distinct patterns of gene expansion and loss in the genomes of plant and animal pathogens. S. parasitica possesses one of the largest repertoires of proteases (270) among eukaryotes that are deployed in waves at different points during infection as determined from RNA-Seq data. In contrast, despite being capable of living saprotrophically, parasitism has led to loss of inorganic nitrogen and sulfur assimilation pathways, strikingly similar to losses in obligate plant pathogenic oomycetes and fungi. The large gene families that are hallmarks of plant pathogenic oomycetes such as Phytophthora appear to be lacking in S. parasitica, including those encoding RXLR effectors, Crinkler's, and Necrosis Inducing-Like Proteins (NLP). S. parasitica also has a very large kinome of 543 kinases, 10% of which is induced upon infection. Moreover, S. parasitica encodes several genes typical of animals or animal-pathogens and lacking from other oomycetes, including disintegrins and galactose-binding lectins, whose expression and evolutionary origins implicate horizontal gene transfer in the evolution of animal pathogenesis in S. parasitica. PMID:23785293

Belmonte, Rodrigo; Löbach, Lars; Christie, James; van den Ackerveken, Guido; Bottin, Arnaud; Bulone, Vincent; Díaz-Moreno, Sara M.; Dumas, Bernard; Fan, Lin; Gaulin, Elodie; Govers, Francine; Grenville-Briggs, Laura J.; Horner, Neil R.; Levin, Joshua Z.; Mammella, Marco; Meijer, Harold J. G.; Morris, Paul; Nusbaum, Chad; Oome, Stan; Phillips, Andrew J.; van Rooyen, David; Rzeszutek, Elzbieta; Saraiva, Marcia; Secombes, Chris J.; Seidl, Michael F.; Snel, Berend; Stassen, Joost H. M.; Sykes, Sean; Tripathy, Sucheta; van den Berg, Herbert; Vega-Arreguin, Julio C.; Wawra, Stephan; Young, Sarah K.; Zeng, Qiandong; Dieguez-Uribeondo, Javier; Russ, Carsten; Tyler, Brett M.; van West, Pieter

2013-01-01

207

Cerebral chemosensory evoked potentials elicited by chemical stimulation of the human olfactory and respiratory nasal mucosa.  

PubMed

A stimulation method was employed by which chemosensory evoked potentials were recorded without tactile somatosensory contamination. The purpose of the study was to determine whether potential components evoked by stimulation of the chemoreceptors of the trigeminal nerve can be distinguished from those of the olfactory nerve. The stimulants (vanillin, phenylethyl alcohol, limonene, menthol, anethol, benzaldehyde, carbon dioxide and a mixture of vanillin and carbon dioxide) were presented in a randomized order to 13 volunteers. Chemosensory evoked potentials to substances which anosmics are unable to perceive (vanillin, phenylethyl alcohol) were termed olfactory evoked potentials; potentials to CO2, which effected no olfactory sensations were termed chemo-somatosensory potentials. Analysis of variance revealed that the different substances resulted in statistically significant changes in the amplitudes and latencies of the evoked potentials, and also in the subjective estimates of intensity. An increased excitation of the somatosensory system resulted in reduced latencies and enhanced amplitudes of the evoked potentials. Responses to the mixture of carbon dioxide and vanillin appeared significantly earlier (50-150 msec) than responses to either substance alone. PMID:2454788

Kobal, G; Hummel, C

1988-01-01

208

Loss of pathogenic potential after cloning of the low-passage Borrelia burgdorferi ZS7 tick isolate: a cautionary note  

Microsoft Academic Search

To study clonal polymorphism of Borrelia burgdorferi antigens in the course of an experimental infection sequence, the low-passage tick isolate ZS7 was cloned by two rounds of\\u000a agar subsurface plating. The resulting clones showed a variable pathogenic potential after experimental infection of C.B-17.scid mice. The test clone 4.2.II, selected for virulence by two passages in immunodeficient scid mice, failed to

Annette Siebers; Weimin Zhong; Reinhard Wallich; Markus M. Simon

1999-01-01

209

Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria  

PubMed Central

Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse. PMID:24904553

Denoncourt, Alix M.; Paquet, Valérie E.; Charette, Steve J.

2014-01-01

210

Application of a multiplex immunoassay for detection of salivary antibody responses to selected potentially waterborne pathogens  

EPA Science Inventory

Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy. Pathogen-specific antibodies in saliva can be used as bioindicators of recent or ongoing infection. Because collection of saliva is easy and painless, i...

211

Viral and Bacterial Interactions in the Upper Respiratory Tract  

PubMed Central

Respiratory infectious diseases are mainly caused by viruses or bacteria that often interact with one another. Although their presence is a prerequisite for subsequent infections, viruses and bacteria may be present in the nasopharynx without causing any respiratory symptoms. The upper respiratory tract hosts a vast range of commensals and potential pathogenic bacteria, which form a complex microbial community. This community is assumed to be constantly subject to synergistic and competitive interspecies interactions. Disturbances in the equilibrium, for instance due to the acquisition of new bacteria or viruses, may lead to overgrowth and invasion. A better understanding of the dynamics between commensals and pathogens in the upper respiratory tract may provide better insight into the pathogenesis of respiratory diseases. Here we review the current knowledge regarding specific bacterial–bacterial and viral–bacterial interactions that occur in the upper respiratory niche, and discuss mechanisms by which these interactions might be mediated. Finally, we propose a theoretical model to summarize and illustrate these mechanisms. PMID:23326226

Bosch, Astrid A. T. M.; Biesbroek, Giske; Trzcinski, Krzysztof; Sanders, Elisabeth A. M.; Bogaert, Debby

2013-01-01

212

Respiratory alkalosis  

MedlinePLUS

Alkalosis - respiratory ... leads to shortness of breath can also cause respiratory alkalosis. ... Treatment is aimed at the condition that causes respiratory alkalosis. Breathing into a paper bag -- or using ...

213

Respiratory Failure  

MedlinePLUS

... the air sacs. This process is called gas exchange. In respiratory failure, gas exchange is impaired. Respiratory failure can be acute (short ... oxygen—into your airways and then your lungs. Rate This Content: Next >> December 19, 2011 Respiratory Failure ...

214

The kinetics of white blood cell counts during vaccination against bovine respiratory disease pathogens and their correlations with lung lesions, diagnosis and average daily gain  

Technology Transfer Automated Retrieval System (TEKTRAN)

Bovine Respiratory Disease (BRD) is the most common disease within US feedlots. Infection can result in morbidity, mortality and reduced average daily gain. The discovery of cheap and reliable methods of prediction and/or protection would be highly advantageous to both breeders and farmers. Cattle (...

215

Infectious pathogens potentially transmitted by semen of the black variety of the Manchega sheep breed: Health constraints for conservation purposes.  

PubMed

Conservation of genetic resources from endangered breeds may be conducted through germinal banks. Preservation of healthy samples is paramount to avoid preserving pathogens shed with germinal products. The black variety of Manchega sheep (BMS), and endangered breed endemic to south-central Spain, is the subject of a conservation program; a germinal bank has been recently established. However, several pathogens circulating in BMS flocks may be shed with semen and threaten BMS preservation. Therefore, we investigated the sanitary status of BMS flocks and semen samples from 4 of the 17 flocks in which this variety is bred worldwide. A serological screening for Maedi-Visna virus, bluetongue virus, Pestivirus spp., Brucella spp., Coxiella burnetii, Chlamydophila spp., Mycobacterium tuberculosis complex, Mycobacterium avium paratuberculosis, Anaplasma spp., Mycoplasma agalactiae, Toxoplasma gondii and Neospora caninum was performed to assess for pathogens potentially shed by semen. Semen samples from 11 of the 35 BMS rams and 4 samples from coexisting rams of the white variety (WMS) were analyzed by PCR to detect Maedi-Visna virus, C. burnetii, Anaplasma marginale, Anaplasma phagocytophilum and T. gondii. Maedi-Visna virus RNA was detected in 3 semen samples (2 BMS and 1 WMS) while C. burnetii DNA was detected in 3 samples from WMS rams. Pathogens that can be transmitted by semen were present in BMS flocks, and Maedi-Visna virus and C. burnetii showed the highest potential for transmission by artificial insemination. Our results point to the need of testing semen samples kept for conservation purposes of BMS before using them for artificial insemination. PMID:25066603

Ruiz-Fons, Francisco; González-Barrio, David; Aguilar-Ríos, Fernando; Soler, Ana J; Garde, José Julián; Gortázar, Christian; Fernández-Santos, María Del Rocío

2014-10-01

216

The Key Events Dose-Response Framework: Its Potential for Application to Foodborne Pathogenic Microorganisms  

PubMed Central

The Key Events Dose-Response Framework (KEDRF) is an analytical approach that facilitates the use of currently available data to gain insight regarding dose-response relationships. The use of the KEDRF also helps identify critical knowledge gaps that once filled, will reduce reliance on assumptions. The present study considers how the KEDRF might be applied to pathogenic microorganisms, using fetal listeriosis resulting from maternal ingestion of food contaminated with L. monocytogenes as an initial example. Major biological events along the pathway between food ingestion and the endpoint of concern are systematically considered with regard to dose (i.e., number of organisms), pathogen factors (e.g., virulence), and protective host mechanisms (e.g., immune response or other homeostatic mechanisms). It is concluded that the KEDRF provides a useful structure for systematically evaluating the complex array of host and pathogen factors that influence the dose-response relationship. In particular, the KEDRF supports efforts to specify and quantify the sources of variability, a prerequisite to strengthening the scientific basis for food safety decision making. PMID:19690997

BUCHANAN, ROBERT L.; HAVELAAR, ARIE H.; SMITH, MARY ALICE; WHITING, RICHARD C.; JULIEN, ELIZABETH

2009-01-01

217

Modeling Human Respiratory Viral Infections in the Cotton Rat (Sigmodon hispidus)  

PubMed Central

For over three decades, cotton rats have been a preferred model for human Respiratory Syncytial Virus (RSV) infection and pathogenesis, and a reliable model for an impressive list of human respiratory pathogens including adenoviruses, para influenza virus, measles, and human metapneumo virus. The most significant contribution of the cotton rat to biomedical research has been the development of anti-RSV antibodies for prophylactic use in high-risk infants. More recently, however, the cotton rat model has been further explored as a model for infection with other respiratory viral pathogens including influenza and rhinovirus.Together with RSV, these viruses inflict the greatest impact on the human respiratory health.This review will focus on the characteristics of these new models and their potential contribution to the development of new therapies.

Blanco, Jorge CG; Boukhvalova, Marina S; Perez, Daniel R; Vogel, Stefanie N; Kajon, Adriana

2014-01-01

218

Respiratory Health Effects of Airborne Particulate Matter: The Role of Particle Size, Composition, and Oxidative Potential—The RAPTES Project  

PubMed Central

Background: Specific characteristics of particulate matter (PM) responsible for associations with respiratory health observed in epidemiological studies are not well established. High correlations among, and differential measurement errors of, individual components contribute to this uncertainty. Objectives: We investigated which characteristics of PM have the most consistent associations with acute changes in respiratory function in healthy volunteers. Methods: We used a semiexperimental design to accurately assess exposure. We increased exposure contrast and reduced correlations among PM characteristics by exposing volunteers at five different locations: an underground train station, two traffic sites, a farm, and an urban background site. Each of the 31 participants was exposed for 5 hr while exercising intermittently, three to seven times at different locations during March–October 2009. We measured PM10, PM2.5, particle number concentrations (PNC), absorbance, elemental/organic carbon, trace metals, secondary inorganic components, endotoxin content, gaseous pollutants, and PM oxidative potential. Lung function [FEV1 (forced expiratory volume in 1 sec), FVC (forced vital capacity), FEF25–75 (forced expiratory flow at 25–75% of vital capacity), and PEF (peak expiratory flow)] and fractional exhaled nitric oxide (FENO) were measured before and at three time points after exposure. Data were analyzed with mixed linear regression. Results: An interquartile increase in PNC (33,000 particles/cm3) was associated with an 11% [95% confidence interval (CI): 5, 17%] and 12% (95% CI: 6, 17%) FENO increase over baseline immediately and at 2 hr postexposure, respectively. A 7% (95% CI: 0.5, 14%) increase persisted until the following morning. These associations were robust and insensitive to adjustment for other pollutants. Similarly consistent associations were seen between FVC and FEV1 with PNC, NO2 (nitrogen dioxide), and NOx (nitrogen oxides). Conclusions: Changes in PNC, NO2, and NOx were associated with evidence of acute airway inflammation (i.e., FENO) and impaired lung function. PM mass concentration and PM10 oxidative potential were not predictive of the observed acute responses. PMID:22552951

Strak, Maciej; Janssen, Nicole A.H; Godri, Krystal J; Gosens, Ilse; Mudway, Ian S; Cassee, Flemming R; Lebret, Erik; Kelly, Frank J; Harrison, Roy M; Steenhof, Maaike; Hoek, Gerard

2012-01-01

219

Engineered nanoparticle respiratory exposure and potential risks for cardiovascular toxicity: predictive tests and biomarkers.  

PubMed

The most attractive properties of engineered nanomaterials for technological applications, including their small size, large surface area, and high reactivity, are also the main factors for their potential toxicity. Based on ambient ultrafine particle research, it is predicted that nanosized particles may have deeper pulmonary deposition, higher biological activity, and a tendency for extrapulmonary translocation compared to larger particles. In this regard, nanoparticle exposure, by direct or indirect mechanisms, may lead to unexpected distant responses, involving the immune system, cardiovascular system, liver, kidney, and brain. The systemic effects may induce or modify the progression of existing diseases such as cardiovascular disease. Current experimental toxicity evaluation of engineered nanomaterials, specifically carbon nanotubes, demonstrated that deposition of these materials in the lung leads to inflammation and fibrosis. The local toxicity is associated with cardiovascular effects related to atherosclerosis. Although translocation of carbon nanotubes into the systemic circulation is hypothetically possible, there is no current evidence to support this hypothesis. However, studies pointed out that carbon nanotube-induced lung inflammation results in a release of inflammatory mediators and activation of blood cells which can contribute to cardiovascular adverse effects. Furthermore, complex protein and gene expression blood analysis can help in development of biomarkers for application in human screening of nanoparticle exposure. Future studies to evaluate the systemic effects of carbon nanotube exposure under workplace or environmental exposure paradigms should be conducted. PMID:19558236

Simeonova, Petia P; Erdely, Aaron

2009-07-01

220

Regrowth of Potential Opportunistic Pathogens and Algae in Reclaimed-Water Distribution Systems ?  

PubMed Central

A study of the quality of reclaimed water in treated effluent, after storage, and at three points in the distribution system of four plants in California, Florida, Massachusetts, and New York was conducted for 1 year. The plants had different treatment processes (conventional versus membrane bioreactor), production capacities, and methods for storage of the water, and the intended end uses of the water were different. The analysis focused on the occurrence of indicator bacteria (heterotrophic bacteria, coliforms, Escherichia coli, and enterococci) and opportunistic pathogens (Aeromonas spp., enteropathogenic E. coli O157:H7, Legionella spp., Mycobacterium spp., and Pseudomonas spp.), as well as algae. Using immunological methods, E. coli O157:H7 was detected in the effluent of only one system, but it was not detected at the sampling points, suggesting that its survival in the system was poor. Although all of the treatment systems effectively reduced the levels of bacteria in the effluent, bacteria regrew in the reservoir and distribution systems because of the loss of residual disinfectant and high assimilable organic carbon levels. In the systems with open reservoirs, algal growth reduced the water quality by increasing the turbidity and accumulating at the end of the distribution system. Opportunistic pathogens, notably Aeromonas, Legionella, Mycobacterium, and Pseudomonas, occurred more frequently than indicator bacteria (enterococci, coliforms, and E. coli). The Mycobacterium spp. were very diverse and occurred most frequently in membrane bioreactor systems, and Mycobacterium cookii was identified more often than the other species. The public health risk associated with these opportunistic pathogens in reclaimed water is unknown. Collectively, our results show the need to develop best management practices for reclaimed water to control bacterial regrowth and degradation of water before it is utilized at the point of use. PMID:20453149

Jjemba, Patrick K.; Weinrich, Lauren A.; Cheng, Wei; Giraldo, Eugenio; LeChevallier, Mark W.

2010-01-01

221

Adaptive Potential of Maritime Pine (Pinus pinaster) Populations to the Emerging Pitch Canker Pathogen, Fusarium circinatum  

PubMed Central

There is a concern on how emerging pests and diseases will affect the distribution range and adaptability of their host species, especially due to different conditions derived from climate change and growing globalization. Fusarium circinatum, which causes pitch canker disease in Pinus species, is an exotic pathogen of recent introduction in Spain that threatens its maritime pine (P. pinaster) stands. To predict the impact this disease will have on the species, we examine host resistance traits and their genetic architecture. Resistance phenotyping was done in a clonal provenance/progeny trial, using three-year-old cuttings artificially inoculated with the pathogen and maintained under controlled environmental conditions. A total number of 670 ramets were assessed, distributed in 10 populations, with a total of 47 families, 2 to 5 half-sibs per family, and 3–7 ramets per clone. High genetic variation was found at the three hierarchical levels studied: population, family and clone, being both additive and non-additive effects important. Narrow-sense and broad-sense heritability estimates were relatively high, with respective values of 0.43–0.58 and 0.51–0.8, depending on the resistance traits measured (lesion length, lesion length rate, time to wilting, and survival). These values suggest the species' high capacity of evolutionary response to the F. circinatum pathogen. A population originated in Northern Spain was the most resistant, while another from Morocco was the most susceptible. The total number of plants that did not show lesion development or presented a small lesion (length<30 mm) was 224 out of 670, indicating a high proportion of resistant trees in the offspring within the analyzed populations. We found large differences among populations and considerable genetic variation within populations, which should allow, through natural or artificial selection, the successful adaptation of maritime pine to pitch canker disease. PMID:25500822

Elvira-Recuenco, Margarita; Iturritxa, Eugenia; Majada, Juan; Alia, Ricardo; Raposo, Rosa

2014-01-01

222

Adaptive potential of maritime pine (Pinus pinaster) populations to the emerging pitch canker pathogen, Fusarium circinatum.  

PubMed

There is a concern on how emerging pests and diseases will affect the distribution range and adaptability of their host species, especially due to different conditions derived from climate change and growing globalization. Fusarium circinatum, which causes pitch canker disease in Pinus species, is an exotic pathogen of recent introduction in Spain that threatens its maritime pine (P. pinaster) stands. To predict the impact this disease will have on the species, we examine host resistance traits and their genetic architecture. Resistance phenotyping was done in a clonal provenance/progeny trial, using three-year-old cuttings artificially inoculated with the pathogen and maintained under controlled environmental conditions. A total number of 670 ramets were assessed, distributed in 10 populations, with a total of 47 families, 2 to 5 half-sibs per family, and 3-7 ramets per clone. High genetic variation was found at the three hierarchical levels studied: population, family and clone, being both additive and non-additive effects important. Narrow-sense and broad-sense heritability estimates were relatively high, with respective values of 0.43-0.58 and 0.51-0.8, depending on the resistance traits measured (lesion length, lesion length rate, time to wilting, and survival). These values suggest the species' high capacity of evolutionary response to the F. circinatum pathogen. A population originated in Northern Spain was the most resistant, while another from Morocco was the most susceptible. The total number of plants that did not show lesion development or presented a small lesion (length<30 mm) was 224 out of 670, indicating a high proportion of resistant trees in the offspring within the analyzed populations. We found large differences among populations and considerable genetic variation within populations, which should allow, through natural or artificial selection, the successful adaptation of maritime pine to pitch canker disease. PMID:25500822

Elvira-Recuenco, Margarita; Iturritxa, Eugenia; Majada, Juan; Alia, Ricardo; Raposo, Rosa

2014-01-01

223

Regrowth of potential opportunistic pathogens and algae in reclaimed-water distribution systems.  

PubMed

A study of the quality of reclaimed water in treated effluent, after storage, and at three points in the distribution system of four plants in California, Florida, Massachusetts, and New York was conducted for 1 year. The plants had different treatment processes (conventional versus membrane bioreactor), production capacities, and methods for storage of the water, and the intended end uses of the water were different. The analysis focused on the occurrence of indicator bacteria (heterotrophic bacteria, coliforms, Escherichia coli, and enterococci) and opportunistic pathogens (Aeromonas spp., enteropathogenic E. coli O157:H7, Legionella spp., Mycobacterium spp., and Pseudomonas spp.), as well as algae. Using immunological methods, E. coli O157:H7 was detected in the effluent of only one system, but it was not detected at the sampling points, suggesting that its survival in the system was poor. Although all of the treatment systems effectively reduced the levels of bacteria in the effluent, bacteria regrew in the reservoir and distribution systems because of the loss of residual disinfectant and high assimilable organic carbon levels. In the systems with open reservoirs, algal growth reduced the water quality by increasing the turbidity and accumulating at the end of the distribution system. Opportunistic pathogens, notably Aeromonas, Legionella, Mycobacterium, and Pseudomonas, occurred more frequently than indicator bacteria (enterococci, coliforms, and E. coli). The Mycobacterium spp. were very diverse and occurred most frequently in membrane bioreactor systems, and Mycobacterium cookii was identified more often than the other species. The public health risk associated with these opportunistic pathogens in reclaimed water is unknown. Collectively, our results show the need to develop best management practices for reclaimed water to control bacterial regrowth and degradation of water before it is utilized at the point of use. PMID:20453149

Jjemba, Patrick K; Weinrich, Lauren A; Cheng, Wei; Giraldo, Eugenio; Lechevallier, Mark W

2010-07-01

224

The potential distance of highly pathogenic avian influenza virus dispersal by mallard, common teal and Eurasian pochard.  

PubMed

Waterbirds represent the major natural reservoir for low pathogenic (LP) avian influenza viruses (AIV). Among the wide diversity of subtypes that have been described, two of them (H5 and H7) may become highly pathogenic (HP) after their introduction into domestic bird populations and cause severe outbreaks, as is the case for HP H5N1 in South-Eastern Asia. Recent experimental studies demonstrated that HP H5N1 AIV infection in ducks does not necessarily have significant pathological effects. These results suggest that wild migratory ducks may asymptomatically carry HP AIV and potentially spread viruses over large geographical distances. In this study, we investigated the potential spreading distance of HP AIV by common teal (Anas crecca), mallard (A. platyrhynchos), and Eurasian pochard (Aythya ferina). Based on capture-mark-recapture method, we characterized their wintering movements from a western Mediterranean wetland (Camargue, South of France) and identified the potential distance and direction of virus dispersal. Such data may be crucial in determining higher-risk areas in the case of HP AIV infection detection in this major wintering quarter, and may serve as a valuable reference for virus outbreaks elsewhere. PMID:20112048

Brochet, Anne-Laure; Guillemain, Matthieu; Lebarbenchon, Camille; Simon, Géraldine; Fritz, Hervé; Green, Andy J; Renaud, François; Thomas, Frédéric; Gauthier-Clerc, Michel

2009-09-01

225

Experimental vaccines against potentially pandemic and highly pathogenic avian influenza viruses  

PubMed Central

Influenza A viruses continue to emerge and re-emerge, causing outbreaks, epidemics and occasionally pandemics. While the influenza vaccines licensed for public use are generally effective against seasonal influenza, issues arise with production, immunogenicity, and efficacy in the case of vaccines against pandemic and emerging influenza viruses, and highly pathogenic avian influenza virus in particular. Thus, there is need of improved influenza vaccines and vaccination strategies. This review discusses advances in alternative influenza vaccines, touching briefly on licensed vaccines and vaccine antigens; then reviewing recombinant subunit vaccines, virus-like particle vaccines and DNA vaccines, with the main focus on virus-vectored vaccine approaches. PMID:23440999

Mooney, Alaina J; Tompkins, S Mark

2013-01-01

226

Lycorine: a potential broad-spectrum agent against crop pathogenic fungi.  

PubMed

A screening test showed that lycorine exhibited significant antifungal activity against 24 pathogenic crop fungi at concentrations of 500 ?g/ml and 100 ?g/ml, respectively. Fusarium graminearum was selected for antifungal mechanism studies by observing its mycelial morphology and investigating the variations in its conductivity. In addition, the substance absorption and metabolism of F. graminearum were explored. The mechanism was revealed as being one by which lycorine destroyed the cellular membrane and further influenced substance absorption and cell metabolism. PMID:24346469

Shen, Jin-Wen; Ruan, Yuan; Ren, Wei; Ma, Bing-Ji; Wang, Xiao-Long; Zheng, Chun-Feng

2014-03-28

227

Presence of potentially pathogenic Babesia sp. for human in Ixodes ricinus in Switzerland.  

PubMed

We have designed and performed a new PCR method based on the 18S rRNA in order to individuate the presence and the identity of Babesia parasites. Out of 1159 Ixodes ricinus (Acari: Ixodidae) ticks collected in four areas of Switzerland, nine were found to contain Babesia DNA. Sequencing of the short amplicon obtained (411-452 bp) allowed the identification of three human pathogenic species: Babesia microti, B. divergens, for the first time in Switzerland, Babesia sp. EU1. We also report coinfections with B. sp. EU1-Borrelia burgdorferi sensu stricto and Babesia sp. EU1-B. afzelii. PMID:16841874

Casati, Simona; Sager, Heinz; Gern, Lise; Piffaretti, Jean-Claude

2006-01-01

228

Balamuthia mandrillaris in South America: An emerging potential hidden pathogen in Perú.  

PubMed

Balamuthia mandrillaris is a free living amoeba that can be isolated from soil. It is an emerging pathogen causing skin lesions as well as CNS involvement with a fatal outcome if untreated. Further, infections can sometimes can also appear in peripheral areas such as extremities (usually knee), or trunk. Moreover, it often progresses to an infiltrative lesion that occasionally becomes ulcerated. In countries like Peru, a skin lesion will precede other symptoms. This primary cutaneous lesion can be present for weeks or even months. However, the appearance of neurological disease predicts a poor prognosis. Diagnosis requires a high level of suspicion. PMID:24858923

Cabello-Vílchez, Alfonso M; Rodríguez-Zaragoza, Salvador; Piñero, José; Valladares, Basilio; Lorenzo-Morales, Jacob

2014-11-01

229

Calpains: Potential Targets for Alternative Chemotherapeutic Intervention Against Human Pathogenic Trypanosomatids  

PubMed Central

The treatment for both leishmaniasis and trypanosomiasis, which are severe human infections caused by trypanosomatids belonging to Leishmania and Trypanosoma genera, respectively, is extremely limited because of concerns of toxicity and efficacy with the available anti-protozoan drugs, as well as the emergence of drug resistance. Consequently, the urgency for the discovery of new trypanosomatid targets and novel bioactive compounds is particularly necessary. In this context, the investigation of changes in parasite gene expression between drug resistant/sensitive strains and in the up-regulation of virulence-related genes in infective forms has brought to the fore the involvement of calpain-like proteins in several crucial pathophysiological processes performed by trypanosomatids. These studies were encouraged by the publication of the complete genome sequences of three human pathogenic trypanosomatids, Trypanosoma brucei, Trypanosoma cruzi and Leishmania major, which allowed in silico analyses that in turn directed the identification of numerous genes with interesting chemotherapeutic characteristics, including a large family of calpain-related proteins, in which to date 23 genes were assigned as calpains in T. brucei, 40 in T. cruzi and 33 in L. braziliensis. In the present review, we intend to add to these biochemical/biological reports the investigations performed upon the inhibitory capability of calpain inhibitors against human pathogenic trypanosomatids. PMID:23899207

M.H, Branquinha; F.A, Marinho; L.S, Sangenito; S.S.C, Oliveira; K.C, Gonçalves; V, Ennes-Vidal; C.M, d’Avila-Levy; A.L.S, Santos

2013-01-01

230

Comparative genomics of multiple strains of Pseudomonas cannabina pv. alisalensis, a potential model pathogen of both Monocots and Dicots  

Technology Transfer Automated Retrieval System (TEKTRAN)

Comparative genomics of closely related pathogens that differ in host range can provide insights into mechanisms of host-pathogen interactions and host adaptation. Sequencing multiple strains of the same pathogen further reveals information concerning pathogen diversity and the molecular basis of vi...

231

[Four cases of respiratory tract infections caused by Corynebacterium pseudodiphtheriticum].  

PubMed

Four cases of respiratory tract infections caused by Corynebacterium pseudodiphtheriticum were reported. The first two patients developed pneumonia with Corynebacterium pseudodiphtheriticum during steroid therapy used against their underlying diseases. The other two patients had acute exacerbation of chronic pulmonary diseases caused by C. pseudodiphtheriticum. These four patients improved by antibiotic therapy. Though nondiphtheria corynebacteria are regarded as "normal flora" when they are isolated from sputum, they should be recognized as potential pathogens. PMID:1402067

Yoshitomi, Y; Higashiyama, Y; Matsuda, H; Mitsutake, K; Miyazaki, Y; Maesaki, S; Yamada, H; Hori, H; Koga, H; Kohno, S

1992-01-01

232

tRNA modification enzymes GidA and MnmE: potential role in virulence of bacterial pathogens.  

PubMed

Transfer RNA (tRNA) is an RNA molecule that carries amino acids to the ribosomes for protein synthesis. These tRNAs function at the peptidyl (P) and aminoacyl (A) binding sites of the ribosome during translation, with each codon being recognized by a specific tRNA. Due to this specificity, tRNA modification is essential for translational efficiency. Many enzymes have been implicated in the modification of bacterial tRNAs, and these enzymes may complex with one another or interact individually with the tRNA. Approximately, 100 tRNA modification enzymes have been identified with glucose-inhibited division (GidA) protein and MnmE being two of the enzymes studied. In Escherichia coli and Salmonella, GidA and MnmE bind together to form a functional complex responsible for the proper biosynthesis of 5-methylaminomethyl-2-thiouridine (mnm?s²U34) of tRNAs. Studies have implicated this pathway in a major pathogenic regulatory mechanism as deletion of gidA and/or mnmE has attenuated several bacterial pathogens like Salmonella enterica serovar Typhimurium, Pseudomonas syringae, Aeromonas hydrophila, and many others. In this review, we summarize the potential role of the GidA/MnmE tRNA modification pathway in bacterial virulence, interactions with the host, and potential therapeutic strategies resulting from a greater understanding of this regulatory mechanism. PMID:25310651

Shippy, Daniel C; Fadl, Amin A

2014-01-01

233

Ultrahigh Resolution and Full-length Pilin Structures with Insights for Filament Assembly, Pathogenic Functions, and Vaccine Potential*  

PubMed Central

Pilin proteins assemble into Type IV pili (T4P), surface-displayed bacterial filaments with virulence functions including motility, attachment, transformation, immune escape, and colony formation. However, challenges in crystallizing full-length fiber-forming and membrane protein pilins leave unanswered questions regarding pilin structures, assembly, functions, and vaccine potential. Here we report pilin structures of full-length DnFimA from the sheep pathogen Dichelobacter nodosus and FtPilE from the human pathogen Francisella tularensis at 2.3 and 1 ? resolution, respectively. The DnFimA structure reveals an extended kinked N-terminal ?-helix, an unusual centrally located disulfide, conserved subdomains, and assembled epitopes informing serogroup vaccines. An interaction between the conserved Glu-5 carboxyl oxygen and the N-terminal amine of an adjacent subunit in the crystallographic dimer is consistent with the hypothesis of a salt bridge between these groups driving T4P assembly. The FtPilE structure identifies an authentic Type IV pilin and provides a framework for understanding the role of T4P in F. tularensis virulence. Combined results define a unified pilin architecture, specialized subdomain roles in pilus assembly and function, and potential therapeutic targets. PMID:22027840

Hartung, Sophia; Arvai, Andrew S.; Wood, Timothy; Kolappan, Subramaniapillai; Shin, David S.; Craig, Lisa; Tainer, John A.

2011-01-01

234

Identification of Common Biological Pathways and Drug Targets Across Multiple Respiratory Viruses Based on Human Host Gene Expression Analysis  

Microsoft Academic Search

BackgroundPandemic and seasonal respiratory viruses are a major global health concern. Given the genetic diversity of respiratory viruses and the emergence of drug resistant strains, the targeted disruption of human host-virus interactions is a potential therapeutic strategy for treating multi-viral infections. The availability of large-scale genomic datasets focused on host-pathogen interactions can be used to discover novel drug targets as

Steven B. Smith; William Dampier; Aydin Tozeren; James R. Brown; Michal Magid-Slav

2012-01-01

235

Characterization of the Viral Microbiome in Patients with Severe Lower Respiratory Tract Infections, Using Metagenomic Sequencing  

Microsoft Academic Search

The human respiratory tract is heavily exposed to microorganisms. Viral respiratory tract pathogens, like RSV, influenza and rhinoviruses cause major morbidity and mortality from respiratory tract disease. Furthermore, as viruses have limited means of transmission, viruses that cause pathogenicity in other tissues may be transmitted through the respiratory tract. It is therefore important to chart the human virome in this

Fredrik Lysholm; Anna Wetterbom; Cecilia Lindau; Hamid Darban; Annelie Bjerkner; Kristina Fahlander; A. Michael Lindberg; Bengt Persson; Tobias Allander; Björn Andersson

2012-01-01

236

Potentially pathogenic Escherichia coli in healthy, pasture-raised sheep on farms and at the abattoir in Brazil.  

PubMed

Sheep harbor pathogenic Escherichia coli, which may cause severe disease in humans. In this study, the prevalence of Shiga toxin-producing E. coli (STEC) and enteropathogenic E. coli (EPEC) was examined in sheep feces and carcasses on three farms and at an abattoir in Brazil. The isolates were further characterized for the presence of markers recently associated with disease in humans, to investigate their possible origin and role as food-borne pathogens. At the abattoir, 99 carcass samples yielded two STEC and 10 EPEC isolates while 101 fecal samples yielded five EPEC and eight STEC isolates. On the other hand, on the farms, 202 samples yielded 44 STEC and eight EPEC isolates. The 77 isolates were typed by PFGE. Isolates with the same PFGE pattern and also those that were not restricted with XbaI were termed as "clones" (n=49). The isolates of any one clone mostly originated from the same sampling site. In addition, seven isolates encoded for novel Stx2 variants and five for Stx2e, the subtype related to porcine edema disease, which was for the first time isolated from sheep feces and carcasses. Also, three stx2-only isolates harbored genes of predicted Stx2 variants that were formed by A and B subunits of different types including Stx2a and Stx2d. The EPEC isolates were heterogeneous, 21 (91.3%) of them possessing efa1, ehxA, lpfAO113 or paa genes associated with diarrhea in humans. Thus, using markers recently associated with disease, we have demonstrated that E. coli similar to those pathogenic for humans are present in the sheep intestinal microflora, particularly at the abattoir, underlining the potential for food-borne transmission. PMID:24438985

Maluta, Renato Pariz; Fairbrother, John Morris; Stella, Ariel Eurides; Rigobelo, Everlon Cid; Martinez, Roberto; de Ávila, Fernando Antonio

2014-02-21

237

Detection of seasonal weight loss and a serologic survey of potential pathogens in wild Pallas' cats (Felis [Otocolobus] manul) of the Daurian Steppe, Russia.  

PubMed

We measured seasonal changes in body mass and pathogen exposure in wild Pallas' cats (Felis [Otocolobus] manul) in the Daurian Steppe of Russia in 2010-11. Pallas' cats lost about 30% of body mass over winter. Tests for antibodies to 15 potential pathogens showed that Pallas' cats were exposed to four pathogens. Two of 16 cats had antibodies to Toxoplasma gondii. Two had antibodies to Mycoplasma sp., and one each had antibodies to Influenza A virus and Feline leukemia virus. The percentage of antibody-positive wild Pallas' cats was lower than results reported for other wild felids in the Russian Far East. PMID:24484481

Naidenko, Sergey V; Pavlova, Ekaterina V; Kirilyuk, Vadim E

2014-04-01

238

The development and use of respirator response functions as part of a workplace exposure monitoring program for control of potential respiratory hazards.  

PubMed

The traditional hierarchy of measures for control of potential respiratory hazards in the workplace includes (in order of preference) engineering controls, workplace practices, and use of respiratory protection. Although third in this hierarchy, respirators can be an important component of the control mix-particularly for difficult-to-control jobs, as an interim measure (pending implementation of other controls), and in cases where exposure is intermittent. One of the problems associated with the use of respirators as a control measure is that valid and adequate data on respirator usage are often not available. Absent these data it is difficult to determine the practical effectiveness of respirators and exposure calculations which include the protective effect of respirators are speculative. This paper presents models (and appropriate statistical fitting techniques) suitable for quantification of respirator usage and defines three potentially useful measures of effectiveness for a respirator program. These models are illustrated with monitoring data on refractory ceramic fiber (RCF) developed as part of a Consent Agreement between the RCF industry and the U.S. Environmental Protection Agency. For this substance there are extensive and comprehensive monitoring data available. The models and methods of analysis may prove applicable for other potential respiratory hazards in the workplace. PMID:9671568

Maxim, L D; Allshouse, J N; Chen, S H; Treadway, J; Venturin, D

1998-04-01

239

White-nosed coatis (Nasua narica) are a potential reservoir of Trypanosoma cruzi and other potentially zoonotic pathogens in Monteverde, Costa Rica.  

PubMed

We studied white-nosed coatis (Nasua narica) in Monteverde, Costa Rica to evaluate their potential as a reservoir for the vector-borne zoonotic parasite Trypanosoma cruzi and other selected microorganisms. We live-trapped 20 coatis in July and August 2011 and tested them for T. cruzi by blood smear, molecular analysis of blood, culture of blood and anal gland secretions, and serology. Seven coatis (35%) were polymerase-chain-reaction-positive for T. cruzi and one coati was also culture positive. We did not detect T. cruzi in anal gland secretions. All coatis were positive for Mycoplasma and Babesia, but were negative for Baylisascaris, Anaplasma, Candidatus Neoehrlichia lotoris, Ehrlichia, Bartonella, and several apicomplexan parasites. The possible pathogenicity of T. cruzi, Babesia, and Mycoplasma in coatis and their transmission potential to humans and domestic animals warrants further investigation. PMID:24502732

Mehrkens, Lea R; Shender, Lisa A; Yabsley, Michael J; Shock, Barbara C; Chinchilla, Federico A; Suarez, Jesus; Gilardi, Kirsten V K

2013-10-01

240

Respiratory Failure  

MedlinePLUS

Respiratory failure happens when not enough oxygen passes from your lungs into your blood. Your body's organs, ... brain, need oxygen-rich blood to work well. Respiratory failure also can happen if your lungs can' ...

241

Larval Bradysia impatiens (Diptera: Sciaridae) potential for vectoring Pythium root rot pathogens.  

PubMed

A series of laboratory experiments were conducted to investigate the capacity of Bradysia impatiens (Johannsen) larvae to ingest propagules from two strains each of Pythium aphanidermatum (Edson) Fitzp. and P. ultimum Trow and transmit the pathogens to healthy geranium seedlings on a filter-paper substrate in petri dishes. The capacity of fungus gnat larvae to transmit P. aphanidermatum to seedlings rooted in a commercial peat-based potting mix and germination of Pythium oospores and hyphal swellings before and after passage through the guts of larval fungus gnats were also examined. Assays revealed that Pythium spp. transmission by larval fungus gnats varied greatly with the assay substrate and also with the number and nature of ingested propagules. Transmission was highest (65%) in the petri dish assays testing larvae fed P. aphanidermatum K-13, a strain that produced abundant oospores. Transmission of strain K-13 was much lower (<6%) in plug cells with potting mix. Larvae were less efficient at vectoring P. ultimum strain PSN-1, which produced few oospores, and no transmission was observed with two non-oospore-producing strains: P. aphanidermatum Pa58 and P. ultimum P4. Passage of P. aphanidermatum K-13 through larval guts significantly increased oospore germination. However, decreased germination of hyphal swellings was observed following larval gut passage for strains of P. ultimum. These results expand previous studies suggesting that larval fungus gnats may vector Pythium spp. PMID:22085299

Braun, S E; Sanderson, J P; Wraight, S P

2012-03-01

242

Submitted to the Journal of the American Water Resources Association Potential Human Health Effects Associated with Pathogens in Urban Wet Weather Flows  

E-print Network

1 Submitted to the Journal of the American Water Resources Association Potential Human Health and indicator organisms found in urban receiving waters are a common cause of concern. Though some question describing the potential human health effects associated with pathogens and commo n indicator organisms found

Pitt, Robert E.

243

Development of an EvaGreen-based multiplex real-time PCR assay with melting curve analysis for simultaneous detection and differentiation of six viral pathogens of porcine reproductive and respiratory disorder.  

PubMed

Concurrent infection of pigs with two or more pathogens is common in pigs under intensive rearing conditions. Porcine circovirus type 2 (PCV2), porcine parvovirus (PPV), porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV), Japanese encephalitis virus (JEV) and pseudorabies virus (PRV) are all associated with reproductive or respiratory disorders or both and can cause significant economic losses in pig production worldwide. An EvaGreen-based multiplex real-time PCR (EG-mPCR) with melting curve analysis was developed in this study for simultaneous detection and differentiation of these six viruses in pigs. This method is able to detect and distinguish PCV2, PPV, PRRSV, CSFV, JEV and PRV with the limits of detection ranging from 100 to 500 copies/?L, high reproducibility, and intra-assay and inter-assay variation ranging from 0.11 to 3.20%. After validation, a total of 118 field samples were tested by the newly developed EG-mPCR. PCV2 was identified in 23%, PPV in 15%, PRRSV in 17% and PRV in 5% of the samples. Concurrent PCV2 and PRRSV infection was detected in 6.7%, PCV2 and PPV in 5% and PPV2 and PRRSV infection was detected in 5% of the cases. The agreement of the EG-mPCR and conventional PCR tests was 99.2%. This EG-mPCR will be a useful, rapid, reliable and cost-effective alternative for routine surveillance testing of viral infections in pigs. PMID:25102430

Rao, Pinbin; Wu, Haigang; Jiang, Yonghou; Opriessnig, Tanja; Zheng, Xiaowen; Mo, Yecheng; Yang, Zongqi

2014-11-01

244

Complete Genome Sequence of Staphylococcus xylosus HKUOPL8, a Potential Opportunistic Pathogen of Mammals  

PubMed Central

We report here the first complete genome sequence of Staphylococcus xylosus strain HKUOPL8, isolated from giant panda feces. The whole genome sequence of this strain will provide an important framework for investigating the genes responsible for potential opportunistic infections with this species, as well as its survival in various environments. PMID:25059860

Ma, Angel Po Yee; Jiang, Jingwei; Tun, Hein Min; Mauroo, Nathalie France; Yuen, Chan San

2014-01-01

245

The Potential Distance of Highly Pathogenic Avian Influenza Virus Dispersal by Mallard, Common Teal and Eurasian  

E-print Network

investigated the potential spreading distance of HP AIV by common teal (Anas crecca), mallard (A. platyrhynchos Don~ana-CSIC, C/ Ame´rico Vespucio s/n, 41092 Sevilla, Spain Abstract: Waterbirds represent the major, approximately 1­5% of migratory mallard (Anas platyrhynchos) and other dabbling ducks are infected with LP AIV

Green, Andy J.

246

Should respiratory care in preterm infants include prophylaxis against respiratory syncytial virus infection? The case in favour.  

PubMed

Respiratory syncytial virus (RSV) is the most significant cause of acute respiratory tract infections (RTI) in infants and young children throughout the world. Preterm infants are at increased risk for severe RSV lower respiratory tract infection due to small lung volumes, a reduced lung surface area, small airways and an increased air space wall thickness. Additionally, the airways of preterm infants have been ventilated mechanically and suctioned and potentially damaged by many microtraumas with disruption of endothelial surfaces enabling pathogens to invade more easily. The immune system of preterm infants is immature resulting in low antibody titers (incomplete transplacental transfer of maternal antibodies) and a reduced cellular immunity with reduced viral clearance. Rehospitalization rates of preterm compared to term infants due to RSV infection are increased as are total morbidity and mortality associated with RSV disease. Palivizumab effectively reduces RSV related rehospitalisation in this high-risk population. PMID:23375547

Resch, Bernhard; Resch, Elisabeth; Müller, Wilhelm

2013-06-01

247

Recent progress on phospholipases: different sources, assay methods, industrial potential and pathogenicity.  

PubMed

Significant studies on phospholipases optimization, characterization, physiological role and industrial potential have been conducted worldwide. Some of them have been directed for biotechnological advances such as gene discovery and functional enhancement by protein engineering. Others reported phospholipases as virulence factor and major cause of pathophysiological effects. A general overview on phospholipase is needed for the identification of new reliable and efficient phospholipase, which would be potentially used in number of industrial and medical applications. Phospholipases catalyse the hydrolysis of one or more ester and phosphodiester bonds of glycerophospholipids. They vary in site of action on phospholipid which can be used industrially for modification/production of new phospholipids. Catalytically active phospholipase mainly use phosphatidylcholine as major substrate, but they can also show specificity with other phospholipids. Several accurate phospholipase assay methods are known, but a rapid and reliable method for high-throughput screening is still a challenge for efficient supply of superior phospholipases and their practical applications. Major application of phospholipase is in industries like oil refinery, health food manufacturing, dairy, cosmetics etc. All types of phospholipases can be involved as virulence factor. They can also be used as diagnostic markers for microbial infection. The importance of phospholipase in virulence is proven and inhibitors of the enzyme can be used as candidate for preventing the associated disease. PMID:21302142

Ramrakhiani, Lata; Chand, Subhash

2011-08-01

248

Heat Shock Proteins: Pathogenic Role in Atherosclerosis and Potential Therapeutic Implications  

PubMed Central

Heat shock proteins (HSPs) are a highly conserved group of proteins that are constitutively expressed and function as molecular chaperones, aiding in protein folding and preventing the accumulation of misfolded proteins. In the arterial wall, HSPs have a protective role under normal physiologic conditions. In disease states, however, HSPs expressed on the vascular endothelial cell surface can act as targets for detrimental autoimmunity due to their highly conserved sequences. Developing therapeutic strategies for atherosclerosis based on HSPs is challenged by the need to balance such physiologic and pathologic roles of these proteins. This paper summarizes the role of HSPs in normal vascular wall processes as well as in the development and progression of atherosclerosis. The potential implications of HSPs in clinical therapies for atherosclerosis are also discussed. PMID:23304456

Kilic, Arman; Mandal, Kaushik

2012-01-01

249

Murine Model of Chronic Respiratory Inflammation  

Microsoft Academic Search

\\u000a The respiratory mucosa is exposed to the external environment each time we breathe and therefore requires a robust and sophisticated\\u000a immune defense system. As with other mucosal sites, the respiratory mucosal immune system must balance its response to pathogens\\u000a while also regulating inflammatory immune cell-mediated tissue damage. In the airways, a failure to tightly control immune\\u000a responses to a pathogen

Amit A. Lugade; Paul N. Bogner; Yasmin Thanavala

250

Combining inferential and deductive approaches to estimate the potential geographical range of the invasive plant pathogen, Phytophthora ramorum.  

PubMed

Phytophthora ramorum, an invasive plant pathogen of unknown origin, causes considerable and widespread damage in plant industries and natural ecosystems of the USA and Europe. Estimating the potential geographical range of P. ramorum has been complicated by a lack of biological and geographical data with which to calibrate climatic models. Previous attempts to do so, using either invaded range data or surrogate species approaches, have delivered varying results. A simulation model was developed using CLIMEX to estimate the global climate suitability patterns for establishment of P. ramorum. Growth requirements and stress response parameters were derived from ecophysiological laboratory observations and site-level transmission and disease factors related to climate data in the field. Geographical distribution data from the USA (California and Oregon) and Norway were reserved from model-fitting and used to validate the models. The model suggests that the invasion of P. ramorum in both North America and Europe is still in its infancy and that it is presently occupying a small fraction of its potential range. Phytophthora ramorum appears to be climatically suited to large areas of Africa, Australasia and South America, where it could cause biodiversity and economic losses in plant industries and natural ecosystems with susceptible hosts if introduced. PMID:23667628

Ireland, Kylie B; Hardy, Giles E St J; Kriticos, Darren J

2013-01-01

251

Combining Inferential and Deductive Approaches to Estimate the Potential Geographical Range of the Invasive Plant Pathogen, Phytophthora ramorum  

PubMed Central

Phytophthora ramorum, an invasive plant pathogen of unknown origin, causes considerable and widespread damage in plant industries and natural ecosystems of the USA and Europe. Estimating the potential geographical range of P. ramorum has been complicated by a lack of biological and geographical data with which to calibrate climatic models. Previous attempts to do so, using either invaded range data or surrogate species approaches, have delivered varying results. A simulation model was developed using CLIMEX to estimate the global climate suitability patterns for establishment of P. ramorum. Growth requirements and stress response parameters were derived from ecophysiological laboratory observations and site-level transmission and disease factors related to climate data in the field. Geographical distribution data from the USA (California and Oregon) and Norway were reserved from model-fitting and used to validate the models. The model suggests that the invasion of P. ramorum in both North America and Europe is still in its infancy and that it is presently occupying a small fraction of its potential range. Phytophthora ramorum appears to be climatically suited to large areas of Africa, Australasia and South America, where it could cause biodiversity and economic losses in plant industries and natural ecosystems with susceptible hosts if introduced. PMID:23667628

Ireland, Kylie B.; Hardy, Giles E. St. J.; Kriticos, Darren J.

2013-01-01

252

Effect of cinnamomum zeylanicum blume essential oil on the growth and morphogenesis of some potentially pathogenic Aspergillus species.  

PubMed

Cinnamomum zeylanicum Blume is known for a wide range of medicinal properties. This study aimed to assess the interference of C. zeylanicum essential oil on the growth and morphogenesis of some potentially pathogenic Aspergillus species. The essential oil presented strong antifungal effect causing the growth inhibition of the assayed strains and development of large growth inhibition zones. MIC50 and MIC90 values were 40 and 80 ?L/mL, respectively. 80, 40 and 20 ?L/mL of the oil strongly inhibited the radial mycelial growth of A. niger, A. flavus and A. fumigatus along 14 days. 80 and 40 ?L/mL of the oil caused a 100% inhibition of the fungal spore germination. Main morphological changes observed under light microscopy provided by the essential oil in the fungal strains were decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure indicating fungal wall degeneration. It is concluded that C. zeylanicum essential oil could be known as potential antifungal compound, particularly, to protect against the growth of Aspergillus species. PMID:24031186

Carmo, Egberto Santos; de Oliveira Lima, Edeltrudes; de Souza, Evandro Leite; de Sousa, Frederico Barbosa

2008-01-01

253

Molecular diagnostics on the toxigenic potential of Fusarium spp. plant pathogens  

PubMed Central

Aims We propose and test an efficient and rapid protocol for the detection of toxigenic Fusarium isolates producing three main types of Fusarium-associated mycotoxins (fumonisins, trichothecenes and zearelanone). Methods and Results The novel approach utilizes partially multiplexed markers based on genes essential for mycotoxin biosynthesis (fumonisin—fum6, fum8; trichothecenes—tri5, tri6; zearalenone, zea2) in Fusarium spp. The protocol has been verified by screening a collection of 96 isolates representing diverse species of filamentous fungi. Each Fusarium isolate was taxonomically identified through both molecular and morphological techniques. The results demonstrate a reliable detection of toxigenic potential for trichothecenes (sensitivity 100%, specificity 95%), zearalenone (sensitivity 100%, specificity 100%) and fumonisins (sensitivity 94%, specificity 88%). Both presence and identity of toxin biosynthetic genes were further confirmed by direct sequencing of amplification products. Conclusions The cross-species-specific PCR markers for key biosynthetic genes provide a sensitive detection of toxigenic fungal isolates, contaminating biological material derived from agricultural fields. Significance and Impact of the Study The conducted study shows that a PCR-based assay of biosynthetic genes is a reliable, cost-effective, early warning system against Fusarium contamination. Its future use as a high-throughput detection strategy complementing chemical assays enables effective targeted application of crop protection products. PMID:24575830

Dawidziuk, A; Koczyk, G; Popiel, D; Kaczmarek, J; Bu?ko, M

2014-01-01

254

Seasonal distribution of potentially pathogenic Acanthamoeba species from drinking water reservoirs in Taiwan.  

PubMed

In order to detect the presence/absence of Acanthamoeba along with geographical variations, water quality variations and seasonal change of Acanthamoeba in Taiwan was investigated by 18S ribosomal RNA (rRNA) gene TaqMan quantitative real-time PCR. Samples were collected quarterly at 19 drinking water reservoir sites from November 2012 to August 2013. Acanthamoeba was detected in 39.5 % (30/76) of the water sample, and the detection rate was 63.2 % (12/19) from samples collected in autumn. The average concentration of Acanthamoeba was 3.59?×?10(4) copies/L. For geographic distribution, the detection rate for Acanthamoeba at the northern region was higher than the central and southern regions in all seasons. Results of Spearman rank test revealed that heterotrophic plate count (HPC) had a negative correlation (R?=?-0.502), while dissolved oxygen (DO) had a positive correlation (R?=?0.463) in summer. Significant differences were found only between the presence/absence of Acanthamoeba and HPC in summer (Mann-Whitney U test, P?potential public health threat and should be further examined. PMID:25263419

Kao, Po-Min; Hsu, Bing-Mu; Hsu, Tsui-Kang; Liu, Jorn-Hon; Chang, Hsiang-Yu; Ji, Wen-Tsai; Tzeng, Kai-Jiun; Huang, Shih-Wei; Huang, Yu-Li

2014-09-30

255

Potentially pathogenic immune cells and networks in apparently healthy lacrimal glands.  

PubMed

Lacrimal glands of people over 40 years old frequently contain lymphocytic infiltrates. Relationships between histopathological presentation and physiological dysfunction are not straightforward. Data from rabbit studies have suggested that at least two immune cell networks form in healthy lacrimal glands, one responding to environmental dryness, the other to high temperatures. New findings indicate that mRNAs for several chemokines and cytokines are expressed primarily in epithelial cells; certain others are expressed in both epithelial cells and immune cells. Transcript abundances vary substantially across glands from animals that have experienced the same conditions, allowing for correlation analyses, which detect clusters that map to various cell types and to networks of coordinately functioning cells. A core network-expressing mRNAs including IL-1?, IL-6, IL-17A, and IL-10-expands adaptively with exposure to dryness, suppressing IFN-?, but potentially causing physiological dysfunction. High temperature elicits concurrent increases of mRNAs for prolactin (PRL), CCL21, and IL-18. PRL is associated with crosstalk to IFN-?, BAFF, and IL-4. The core network reacts to the resulting PRL-BAFF-IL-4 network, creating a profile reminiscent of Sjögren's disease. In a warmer, moderately dry setting, PRL-associated increases of IFN-? are associated with suppression of IL-10 and augmentations of IL-1? and IL-17, creating a profile reminiscent of severe chronic inflammation. PMID:25557346

Mircheff, Austin K; Wang, Yanru; Ding, Chuanqing; Warren, Dwight W; Schechter, Joel E

2015-01-01

256

Microbial Monitoring of Pathogens by Comparing Multiple Real-Time PCR Platforms for Potential Space Applications  

NASA Technical Reports Server (NTRS)

The International Space Station (ISS) is a closed environment wih rotations of crew and equipment each introducing their own microbial flora making it necessary to monitor the air, surfaces, and water for microbial contamination. Current microbial monitoring includes labor and time intensive methods to enumerate total bacterial and fungal cells with limited characterization during in-flight testing. Although this culture-based method has been sufficient for monitoring the ISS, future long duration missions will need to perform more comprehensive characterization in-flight, since sample return and ground characterization may not be available. A workshop was held in 2011 at the Johnson Space Center to discuss alternative methodologies and technologies suitable for microbial monitoring for these longterm exploration missions where molecular-based methodologies, such as polymerase chain reaction (PCR), were recommended. In response, a multi-center (Marshall Space Flight Center, Johnson Space Center, Jet Propulsion Laboratory, and Kennedy Space Center) collaborative research effort was initiated to explore novel commercial-off-the-shelf hardware options for spaceflight environmental monitoring. The goal was to evaluate quantitative/semi-quantitative PCR approaches to space applications for low cost in-flight rapid identification of microorganisms affecting crew safety. The initial phase of this project identified commercially available platforms that could be minimally modified to perform nominally in microgravity followed by proof-of-concept testing on the highest qualifying candidates with a universally available test organism, Salmonella enterica. The platforms evaluated during proof-of-concept testing included the iCubate 2.0(TradeMark) (iCubate, Huntsville, AL), RAZOR EX (BioFire Diagnostics; Salt Lake City, Utah) and SmartCycler(TradeMark) (Cepheid; Sunnyvale, CA). The analysis identified two potential technologies (iCubate 2.0 and RAZOR EX) that were able to perform sample-to-answer testing with cell sample concentrations between SO to 400 cells. In addition, the commercial systems were evaluated for initial flight safety and readiness, sample concentration needs were reviewed, and a competitive procurement of commercially available platforms was initiated.

Birmele, Michele

2012-01-01

257

DISTRIBUTION OF OROBAMCHE ALBA STEPHAN EX WILLD - POTENTIAL HOST OF PHYTOPHAGOUS ANIMALS AND PATHOGENS ATTACKING THE PEST OROBANCHE RAMOSA L. IN SLOVAKIA  

Microsoft Academic Search

Summary During 2002 and 2003, the survey of distribution of wild broomrapes (Orobanche sp.), as potential hosts of phytophagous animals and pathogens, was done in Slovakia. 50 localities were checked and broomrapes occurred on 30 of them. One of the most abundant broomrape species was Orobanche alba Stephan ex Willd., which infested plants from the genus Thymus L. and was

Peter TÓTH; A. Hlinku

258

Plant extracts, spices, and essential oils inactivate E. coli O157:H7 pathogens and reduce formation of potentially carcinogenic heterocyclic amines in grilled beef patties  

Technology Transfer Automated Retrieval System (TEKTRAN)

Meats need to be sufficiently heated to inactivate foodborne pathogens such as Escherichia coli O157:H7. High-temperature heat treatment used to prepare well-done meats could, however, increase the formation of potentially carcinogenic heterocyclic amines (HCAs). The objective of this study was to ...

259

Respiratory Virus Detection in Immunocompromised Patients with FilmArray Respiratory Panel Compared to Conventional Methods  

PubMed Central

Respiratory virus infections cause significant morbidity and mortality in immunocompromised patients. Timely diagnosis is needed to provide optimal clinical care. Diagnostic tests routinely available at most institutions are limited by poor sensitivity and a slow turnaround time. We collected 90 respiratory samples from 87 immunocompromised patients (56 bronchoalveolar lavage and 34 nasopharyngeal aspirate samples) in order to compare the performance of routine respiratory virus testing available at our institution to the FilmArray respiratory panel assay, a novel diagnostic tool which utilizes multiplex PCR to test for 21 respiratory pathogens with a 1-h turnaround time. Samples with discordant results and 13 samples with concordant results underwent further verification testing by laboratory-developed real-time PCR. The FilmArray assay identified viral pathogens in more samples than did clinical testing (30/90 versus 16/90; McNemar P = 0.001). Most of the additional viral pathogens identified by the FilmArray respiratory panel assay that were confirmed by verification testing were pathogens not assessed by routine clinical tests, including rhinovirus/enterovirus, human metapneumovirus, and coronavirus. The FilmArray respiratory panel assay allowed for increased identification of respiratory viral pathogens in this cohort of immunocompromised patients. PMID:22814461

Gagne, Lisa S.; Stock, Shannon R.; Marty, Francisco M.; Gelman, Rebecca S.; Marasco, Wayne A.; Poritz, Mark A.; Baden, Lindsey R.

2012-01-01

260

Emerging novel and antimicrobial-resistant respiratory tract infections: new drug development and therapeutic options.  

PubMed

The emergence and spread of antimicrobial-resistant bacterial, viral, and fungal pathogens for which diminishing treatment options are available is of major global concern. New viral respiratory tract infections with epidemic potential, such as severe acute respiratory syndrome, swine-origin influenza A H1N1, and Middle East respiratory syndrome coronavirus infection, require development of new antiviral agents. The substantial rise in the global numbers of patients with respiratory tract infections caused by pan-antibiotic-resistant Gram-positive and Gram-negative bacteria, multidrug-resistant Mycobacterium tuberculosis, and multiazole-resistant fungi has focused attention on investments into development of new drugs and treatment regimens. Successful treatment outcomes for patients with respiratory tract infections across all health-care settings will necessitate rapid, precise diagnosis and more effective and pathogen-specific therapies. This Series paper describes the development and use of new antimicrobial agents and immune-based and host-directed therapies for a range of conventional and emerging viral, bacterial, and fungal causes of respiratory tract infections. PMID:25189352

Zumla, Alimuddin; Memish, Ziad A; Maeurer, Markus; Bates, Matthew; Mwaba, Peter; Al-Tawfiq, Jaffar A; Denning, David W; Hayden, Frederick G; Hui, David S

2014-11-01

261

[Acute respiratory distress syndrome complicating an acute chest syndrome: potential benefit of early combination of exchange transfusion and prone positioning].  

PubMed

We report the case of an 8-year-old sickle cell anemia child admitted for acute respiratory failure complicating acute chest syndrome. Because of threatening respiratory failure, tracheal intubation was performed immediately after ICU admission. The patient met the criteria for ARDS with a PaO2/FiO2 ratio of 94mmHg. An exchange transfusion was performed immediately after admission. HbS fraction failed from 69 % to 30 %. Fluid resuscitation with crystalloids and continuous norepinephrine infusion was needed because of arterial hypotension. Due to persistent severe hypoxemia with PaO2/FiO2 ratio below 100, the patient was placed in prone positioning 16hours after admission, for a total duration of 14hours. A second 12-hour session of prone positioning was performed 41h after admission and PaO2/FiO2 ratio reached 300mmHg after. Treatment also included transfusion of two red-cell pack on day 1 and 2 after admission in order to maintain hemoglobin level above 8g/dL, and a daily folic acid supplementation. The control of hyperthermia was achieved by a systematic parenteral administration of paracetamol. Cefotaxime and erythromycine were continued until day 7 despite the negative results of all bacteriological samples. The outcome was favorable from day 3 and the patient met the criteria for extubation on day 5. A first attempt of extubation was performed on day 5, but re-intubation was required because of laryngeal edema. Steroids were given for 48h and the patient was successfully extubated on day 7. She was discharged from the ICU on day 8, and from the hospital on day 12. We discuss the various treatments available for the management of acute chest syndrome and their actual relevance in acute respiratory distress syndrome in the absence of strong evidence-based guidelines in pediatric ARDS. PMID:25458459

Dusacre, J-A; Pons, B; Piednoir, P; Soubirou, J-F; Thiery, G

2014-12-01

262

Network analysis suggests a potentially 'evil' alliance of opportunistic pathogens inhibited by a cooperative network in human milk bacterial communities.  

PubMed

The critical importance of human milk to infants and even human civilization has been well established. Yet our understanding of the milk microbiome has been limited to cataloguing OTUs and computation of community diversity. To the best of our knowledge, there has been no report on the bacterial interactions within the milk microbiome. To bridge this gap, we reconstructed a milk bacterial community network based on Hunt et al. Our analysis revealed that the milk microbiome network consists of two disconnected sub-networks. One sub-network is a fully connected complete graph consisting of seven genera as nodes and all of its pair-wise interactions among the bacteria are facilitative or cooperative. In contrast, the interactions in the other sub-network of eight nodes are mixed but dominantly cooperative. Somewhat surprisingly, the only 'non-cooperative' nodes in the second sub-network are mutually cooperative Staphylococcus and Corynebacterium that include some opportunistic pathogens. This potentially 'evil' alliance between Staphylococcus and Corynebacterium could be inhibited by the remaining nodes that cooperate with one another in the second sub-network. We postulate that the 'confrontation' between the 'evil' alliance and 'benign' alliance and the shifting balance between them may be responsible for dysbiosis of the milk microbiome that permits mastitis. PMID:25651890

Sam Ma, Zhanshan; Guan, Qiong; Ye, Chengxi; Zhang, Chengchen; Foster, James A; Forney, Larry J

2015-01-01

263

Alternative activation of macrophages by IL-4 impairs phagocytosis of pathogens but potentiates microbial-induced signalling and cytokine secretion.  

PubMed

Alternatively activated macrophages play an important role in host defense in the context of a T helper type 2 (Th2) microenvironment such as parasitic infection. However, the role of these macrophages during secondary challenge with Th1 pathogens is poorly defined. In this study, thioglycollate-elicited mouse peritoneal macrophages were treated with interleukin-4 (IL-4) or IL-13 in vitro and challenged with Neisseria meningitidis. After 8 to 12 hours of IL-4 pretreatment, the nonopsonic phagocytic uptake of N meningitidis was markedly reduced, depending on the common IL-4Ralpha chain, but independent of Scavenger receptor A and macrophage receptor with collagenous structure (MARCO), 2 known receptors for N meningitidis. Inhibition of phagocytosis extended to several other microbial particles, zymosan, and other bacteria. Concomitantly, IL-4 potentiated the secretion of proinflammatory cytokines, after additional bacterial stimulation, which depended on the MyD88 signaling pathway. Similar results were obtained after intraperitoneal stimulation of IL-4 and N meningitidis in vivo. Further in vitro studies showed a striking correlation with inhibition of Akt phosphorylation and stimulation of the mitogen-activated protein kinase pathway; inhibition of phagocytosis was associated with inhibition of phagosome formation. These findings are relevant to host defense in mixed infections within a Th2 microenvironment and shed light on immunologic functions associated with alternative priming and full activation of macrophages. PMID:19880493

Varin, Audrey; Mukhopadhyay, Subhankar; Herbein, Georges; Gordon, Siamon

2010-01-14

264

First Report of Pseudobodo sp, a New Pathogen for a Potential Energy-Producing Algae: Chlorella vulgaris Cultures  

PubMed Central

Chlorella vulgaris, is a kind of single-celled green algae, which could serve as a potential source of food and energy because of its photosynthetic efficiency. In our study, a pathogenic organism targeting C. vulgaris was discovered. The algae-lytic activity relates to a fraction from lysates of infected C. vulgaris that was blocked upon filtration through a 3 µm filter. 18S rRNA gene sequence analysis revealed that it shared 99.0% homology with the protist Pseudobodo tremulans. Scanning electron microscope analysis showed that Pseudobodo sp. KD51 cells were approximately 4–5 µm long, biflagellate with an anterior collar around the anterior part of the cell in unstressed feeding cells. Besides the initial host, Pseudobodo sp. KD51 could also kill other algae, indicating its relatively wide predatory spectrum. Heat stability, pH and salinity tolerance experiments were conducted to understand their effects on its predatory activities, and the results showed that Pseudobodo sp. KD51 was heat-sensitive, and pH and salinity tolerant. PMID:24599263

Zhang, Bangzhou; Yang, Luxi; Zhang, Huajun; Zhang, Jingyan; Li, Yi; Zheng, Wei; Tian, Yun; Liu, Jingwen; Zheng, Tianling

2014-01-01

265

Network analysis suggests a potentially ‘evil' alliance of opportunistic pathogens inhibited by a cooperative network in human milk bacterial communities  

PubMed Central

The critical importance of human milk to infants and even human civilization has been well established. Yet our understanding of the milk microbiome has been limited to cataloguing OTUs and computation of community diversity. To the best of our knowledge, there has been no report on the bacterial interactions within the milk microbiome. To bridge this gap, we reconstructed a milk bacterial community network based on Hunt et al. Our analysis revealed that the milk microbiome network consists of two disconnected sub-networks. One sub-network is a fully connected complete graph consisting of seven genera as nodes and all of its pair-wise interactions among the bacteria are facilitative or cooperative. In contrast, the interactions in the other sub-network of eight nodes are mixed but dominantly cooperative. Somewhat surprisingly, the only ‘non-cooperative' nodes in the second sub-network are mutually cooperative Staphylococcus and Corynebacterium that include some opportunistic pathogens. This potentially ‘evil' alliance between Staphylococcus and Corynebacterium could be inhibited by the remaining nodes that cooperate with one another in the second sub-network. We postulate that the ‘confrontation' between the ‘evil' alliance and ‘benign' alliance and the shifting balance between them may be responsible for dysbiosis of the milk microbiome that permits mastitis. PMID:25651890

(Sam) Ma, Zhanshan; Guan, Qiong; Ye, Chengxi; Zhang, Chengchen; Foster, James A.; Forney, Larry J.

2015-01-01

266

Rabbit respiratory system: clinical anatomy, physiology and disease.  

PubMed

Rabbits are obligate nose breathers due to their epiglottis positioned rostrally to the soft palate. Any obstruction within the nasal cavity will produce a respiratory wheeze with increased respiratory effort. Respiratory diseases are a major cause of morbidity and mortality in rabbits. This article focuses on these diseases and their causative pathogens. PMID:21601814

Johnson-Delaney, Cathy A; Orosz, Susan E

2011-05-01

267

Assessment of Shiga toxin-producing Escherichia coli isolates from wildlife meat as potential pathogens for humans.  

PubMed

A total of 140 Shiga toxin-producing Escherichia coli (STEC) strains from wildlife meat (deer, wild boar, and hare) isolated in Germany between 1998 and 2006 were characterized with respect to their serotypes and virulence markers associated with human pathogenicity. The strains grouped into 38 serotypes, but eight O groups (21, 146, 128, 113, 22, 88, 6, and 91) and four H types (21, 28, 2, and 8) accounted for 71.4% and 75.7% of all STEC strains from game, respectively. Eighteen of the serotypes, including enterohemorrhagic E. coli (EHEC) O26:[H11] and O103:H2, were previously found to be associated with human illness. Genes linked to high-level virulence for humans (stx(2), stx(2d), and eae) were present in 46 (32.8%) STEC strains from game. Fifty-four STEC isolates from game belonged to serotypes which are frequently found in human patients (O103:H2, O26:H11, O113:H21, O91:H21, O128:H2, O146:H21, and O146:H28). These 54 STEC isolates were compared with 101 STEC isolates belonging to the same serotypes isolated from farm animals, from their food products, and from human patients. Within a given serotype, most STEC strains were similar with respect to their stx genotypes and other virulence attributes, regardless of origin. The 155 STEC strains were analyzed for genetic similarity by XbaI pulsed-field gel electrophoresis. O103:H2, O26:H11, O113:H21, O128:H2, and O146:H28 STEC isolates from game were 85 to 100% similar to STEC isolates of the same strains from human patients. By multilocus sequence typing, game EHEC O103:H2 strains were attributed to a clonal lineage associated with hemorrhagic diseases in humans. The results from our study indicate that game animals represent a reservoir for and a potential source of human pathogenic STEC and EHEC strains. PMID:19700552

Miko, Angelika; Pries, Karin; Haby, Sabine; Steege, Katja; Albrecht, Nadine; Krause, Gladys; Beutin, Lothar

2009-10-01

268

Analyzing indicator microorganisms, antibiotic resistant Escherichia coli, and regrowth potential of foodborne pathogens in various organic fertilizers.  

PubMed

This study analyzed various organic fertilizers for indicator microorganisms, pathogens, and antibiotic-resistant Escherichia coli, and evaluated the growth potential of E. coli O157:H7 and Salmonella in fertilizers. A microbiological survey was conducted on 103 organic fertilizers from across the United States. Moisture content ranged from approximately 1% to 86.4%, and the average pH was 7.77. The total aerobic mesophiles ranged from approximately 3 to 9 log colony-forming units (CFU)/g. Enterobacteriaceae populations were in the range of <1 to approximately 7 log CFU/g, while coliform levels varied from <1 to approximately 6 log CFU/g. Thirty samples (29%) were positive for E. coli, with levels reaching approximately 6 log CFU/g. There were no confirmed positives for E. coli O157:H7, Salmonella, or Listeria monocytogenes. The majority of E. coli isolates (n=73), confirmed by glutamate decarboxylase (gad) PCR, were from group B1 (48%) and group A (32%). Resistance to 16 antibiotics was examined for 73 E. coli isolates, with 11 isolates having resistance to at least one antibiotic, 5 isolates to ? 2 antibiotics, and 2 isolates to ? 10 antibiotics. In the presence of high levels of background aerobic mesophiles, Salmonella and E. coli O157:H7 grew approximately 1 log CFU/g within 1 day of incubation in plant-based compost and fish emulsion-based compost, respectively. With low levels of background aerobic mesophiles, Salmonella grew approximately 2.6, 3.0, 3.0, and 3.2 log CFU/g in blood, bone, and feather meals and the mixed-source fertilizer, respectively, whereas E. coli O157:H7 grew approximately 4.6, 4.0, 4.0, and 4.8 log CFU/g, respectively. Our results revealed that the microbiological quality of organic fertilizers varies greatly, with some fertilizers containing antibiotic resistant E. coli and a few supporting the growth of foodborne pathogens after reintroduction into the fertilizer. PMID:23614803

Miller, Cortney; Heringa, Spencer; Kim, Jinkyung; Jiang, Xiuping

2013-06-01

269

Phylogenetic identification of bacterial MazF toxin protein motifs among probiotic strains and foodborne pathogens and potential implications of engineered probiotic intervention in food  

PubMed Central

Background Toxin-antitoxin (TA) systems are commonly found in bacteria and Archaea, and it is the most common mechanism involved in bacterial programmed cell death or apoptosis. Recently, MazF, the toxin component of the toxin-antitoxin module, has been categorized as an endoribonuclease, or it may have a function similar to that of a RNA interference enzyme. Results In this paper, with comparative data and phylogenetic analyses, we are able to identify several potential MazF-conserved motifs in limited subsets of foodborne pathogens and probiotic strains and further provide a molecular basis for the development of engineered/synthetic probiotic strains for the mitigation of foodborne illnesses. Our findings also show that some probiotic strains, as fit as many bacterial foodborne pathogens, can be genetically categorized into three major groups based on phylogenetic analysis of MazF. In each group, potential functional motifs are conserved in phylogenetically distant species, including foodborne pathogens and probiotic strains. Conclusion These data provide important knowledge for the identification and computational prediction of functional motifs related to programmed cell death. Potential implications of these findings include the use of engineered probiotic interventions in food or use of a natural probiotic cocktail with specificity for controlling targeted foodborne pathogens. PMID:23186337

2012-01-01

270

Molecular characterization of the porcine S100A6 gene and analysis of its expression in pigs infected with highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV).  

PubMed

Our previous microarray study revealed that S100A6 was significantly upregulated in porcine alveolar macrophages (PAMs) infected with highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV). In the present study, we cloned both cDNA and genomic DNA sequences of the gene. Transient transfection indicated that the porcine S100A6 protein was located in the nucleus and cytoplasm. Reverse transcription polymerase chain reaction (RT-PCR) revealed that the porcine S100A6 gene was highly expressed in the kidney and subcutaneous fat. Polyinosinic-polycytidylic acid [poly (I:C)] induced porcine S100A6 gene expression in PK-15 cells. Quantitative real-time PCR (Q-PCR) analysis further showed that the porcine S100A6 gene was upregulated in different cells and tissues of Tongcheng pigs infected with HP-PRRSV. Chromosome walking obtained the porcine S100A6 promoter region and then luciferase reporter assays confirmed its regulatory activities. We observed a putative NF-?B binding site in the core promoter region, which may explain the upregulation of porcine S100A6 in response to PRRSV. Transfection of NF-?B (p65 subunit) intensely induced the promoter activity of the porcine S100A6 gene, while an NF-?B inhibitor, pyrrolidine dithiocarbamate (PDTC), inhibited this activity. Furthermore, compared to its wild type, the promoter activity was significantly reduced when it contained a mutant NF-?B binding site. All these results provide a solid foundation to further investigate how S100A6 is involved in PRRSV infection. PMID:25480733

Zhou, Xiang; Wang, Peng; Michal, Jennifer J; Wang, Yan; Zhao, Jinhua; Jiang, Zhihua; Liu, Bang

2014-12-01

271

77 FR 68789 - Establishing a List of Qualifying Pathogens That Have the Potential To Pose a Serious Threat to...  

Federal Register 2010, 2011, 2012, 2013

...A) resistant [G]ram positive pathogens, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Staphylococcus aureus, and vancomycin-resistant [E]nterococcus; (B) multi-drug resistant...

2012-11-16

272

The Potential Distance of Highly Pathogenic Avian Influenza Virus Dispersal by Mallard, Common Teal and Eurasian Pochard  

Microsoft Academic Search

Waterbirds represent the major natural reservoir for low pathogenic (LP) avian influenza viruses (AIV). Among the wide diversity\\u000a of subtypes that have been described, two of them (H5 and H7) may become highly pathogenic (HP) after their introduction into\\u000a domestic bird populations and cause severe outbreaks, as is the case for HP H5N1 in South-Eastern Asia. Recent experimental\\u000a studies demonstrated

Anne-Laure Brochet; Matthieu Guillemain; Camille Lebarbenchon; Géraldine Simon; Hervé Fritz; Andy J. Green; François Renaud; Frédéric Thomas; Michel Gauthier-Clerc

2009-01-01

273

Gorilla gorilla gorilla gut: a potential reservoir of pathogenic bacteria as revealed using culturomics and molecular tools.  

PubMed

Wild apes are considered to be the most serious reservoir and source of zoonoses. However, little data are available about the gut microbiota and pathogenic bacteria in gorillas. For this propose, a total of 48 fecal samples obtained from 21 Gorilla gorilla gorilla individuals (as revealed via microsatellite analysis) were screened for human bacterial pathogens using culturomics and molecular techniques. By applying culturomics to one index gorilla and using specific media supplemented by plants, we tested 12,800 colonies and identified 147 different bacterial species, including 5 new species. Many opportunistic pathogens were isolated, including 8 frequently associated with human diseases; Mycobacterium bolletii, Proteus mirabilis, Acinetobacter baumannii, Klebsiella pneumoniae, Serratia marcescens, Escherichia coli, Staphylococcus aureus and Clostridium botulinum. The genus Treponema accounted for 27.4% of the total reads identified at the genus level via 454 pyrosequencing. Using specific real-time PCR on 48 gorilla fecal samples, in addition to classical human pathogens, we also observed the fastidious bacteria Bartonella spp. Borrelia spp., Coxiella burnetii and Tropheryma whipplei in the gorilla population. We estimated that the prevalence of these pathogens vary between 4.76% and 85.7%. Therefore, gorillas share many bacterial pathogens with humans suggesting that they could be a reservoir for their emergence. PMID:25417711

Bittar, Fadi; Keita, Mamadou B; Lagier, Jean-Christophe; Peeters, Martine; Delaporte, Eric; Raoult, Didier

2014-01-01

274

Gorilla gorilla gorilla gut: a potential reservoir of pathogenic bacteria as revealed using culturomics and molecular tools  

PubMed Central

Wild apes are considered to be the most serious reservoir and source of zoonoses. However, little data are available about the gut microbiota and pathogenic bacteria in gorillas. For this propose, a total of 48 fecal samples obtained from 21 Gorilla gorilla gorilla individuals (as revealed via microsatellite analysis) were screened for human bacterial pathogens using culturomics and molecular techniques. By applying culturomics to one index gorilla and using specific media supplemented by plants, we tested 12,800 colonies and identified 147 different bacterial species, including 5 new species. Many opportunistic pathogens were isolated, including 8 frequently associated with human diseases; Mycobacterium bolletii, Proteus mirabilis, Acinetobacter baumannii, Klebsiella pneumoniae, Serratia marcescens, Escherichia coli, Staphylococcus aureus and Clostridium botulinum. The genus Treponema accounted for 27.4% of the total reads identified at the genus level via 454 pyrosequencing. Using specific real-time PCR on 48 gorilla fecal samples, in addition to classical human pathogens, we also observed the fastidious bacteria Bartonella spp. Borrelia spp., Coxiella burnetii and Tropheryma whipplei in the gorilla population. We estimated that the prevalence of these pathogens vary between 4.76% and 85.7%. Therefore, gorillas share many bacterial pathogens with humans suggesting that they could be a reservoir for their emergence. PMID:25417711

Bittar, Fadi; Keita, Mamadou B.; Lagier, Jean-Christophe; Peeters, Martine; Delaporte, Eric; Raoult, Didier

2014-01-01

275

Characterizing the interface between wild ducks and poultry to evaluate the potential of transmission of avian pathogens  

PubMed Central

Background Characterizing the interface between wild and domestic animal populations is increasingly recognized as essential in the context of emerging infectious diseases (EIDs) that are transmitted by wildlife. More specifically, the spatial and temporal distribution of contact rates between wild and domestic hosts is a key parameter for modeling EIDs transmission dynamics. We integrated satellite telemetry, remote sensing and ground-based surveys to evaluate the spatio-temporal dynamics of indirect contacts between wild and domestic birds to estimate the risk that avian pathogens such as avian influenza and Newcastle viruses will be transmitted between wildlife to poultry. We monitored comb ducks (Sarkidiornis melanotos melanotos) with satellite transmitters for seven months in an extensive Afro-tropical wetland (the Inner Niger Delta) in Mali and characterise the spatial distribution of backyard poultry in villages. We modelled the spatial distribution of wild ducks using 250-meter spatial resolution and 8-days temporal resolution remotely-sensed environmental indicators based on a Maxent niche modelling method. Results Our results show a strong seasonal variation in potential contact rate between wild ducks and poultry. We found that the exposure of poultry to wild birds was greatest at the end of the dry season and the beginning of the rainy season, when comb ducks disperse from natural water bodies to irrigated areas near villages. Conclusions Our study provides at a local scale a quantitative evidence of the seasonal variability of contact rate between wild and domestic bird populations. It illustrates a GIS-based methodology for estimating epidemiological contact rates at the wildlife and livestock interface integrating high-resolution satellite telemetry and remote sensing data. PMID:22085837

2011-01-01

276

Experimental antibiotic treatment identifies potential pathogens of white band disease in the endangered Caribbean coral Acropora cervicornis  

PubMed Central

Coral diseases have been increasingly reported over the past few decades and are a major contributor to coral decline worldwide. The Caribbean, in particular, has been noted as a hotspot for coral disease, and the aptly named white syndromes have caused the decline of the dominant reef building corals throughout their range. White band disease (WBD) has been implicated in the dramatic loss of Acropora cervicornis and Acropora palmata since the 1970s, resulting in both species being listed as critically endangered on the International Union for Conservation of Nature Red list. The causal agent of WBD remains unknown, although recent studies based on challenge experiments with filtrate from infected hosts concluded that the disease is probably caused by bacteria. Here, we report an experiment using four different antibiotic treatments, targeting different members of the disease-associated microbial community. Two antibiotics, ampicillin and paromomycin, arrested the disease completely, and by comparing with community shifts brought about by treatments that did not arrest the disease, we have identified the likely candidate causal agent or agents of WBD. Our interpretation of the experimental treatments is that one or a combination of up to three specific bacterial types, detected consistently in diseased corals but not detectable in healthy corals, are likely causal agents of WBD. In addition, a histophagous ciliate (Philaster lucinda) identical to that found consistently in association with white syndrome in Indo-Pacific acroporas was also consistently detected in all WBD samples and absent in healthy coral. Treatment with metronidazole reduced it to below detection limits, but did not arrest the disease. However, the microscopic disease signs changed, suggesting a secondary role in disease causation for this ciliate. In future studies to identify a causal agent of WBD via tests of Henle–Koch's postulates, it will be vital to experimentally control for populations of the other potential pathogens identified in this study. PMID:24943374

Sweet, M. J.; Croquer, A.; Bythell, J. C.

2014-01-01

277

Comparative Genomics of Multiple Strains of Pseudomonas cannabina pv. alisalensis, a Potential Model Pathogen of Both Monocots and Dicots  

PubMed Central

Comparative genomics of closely related pathogens that differ in host range can provide insights into mechanisms of host-pathogen interactions and host adaptation. Furthermore, sequencing of multiple strains with the same host range reveals information concerning pathogen diversity and the molecular basis of virulence. Here we present a comparative analysis of draft genome sequences for four strains of Pseudomonas cannabina pathovar alisalensis (Pcal), which is pathogenic on a range of monocotyledonous and dicotyledonous plants. These draft genome sequences provide a foundation for understanding host range evolution across the monocot-dicot divide. Like other phytopathogenic pseudomonads, Pcal strains harboured a hrp/hrc gene cluster that codes for a type III secretion system. Phylogenetic analysis based on the hrp/hrc cluster genes/proteins, suggests localized recombination and functional divergence within the hrp/hrc cluster. Despite significant conservation of overall genetic content across Pcal genomes, comparison of type III effector repertoires reinforced previous molecular data suggesting the existence of two distinct lineages within this pathovar. Furthermore, all Pcal strains analyzed harbored two distinct genomic islands predicted to code for type VI secretion systems (T6SSs). While one of these systems was orthologous to known P. syringae T6SSs, the other more closely resembled a T6SS found within P. aeruginosa. In summary, our study provides a foundation to unravel Pcal adaptation to both monocot and dicot hosts and provides genetic insights into the mechanisms underlying pathogenicity. PMID:23555661

Sarris, Panagiotis F.; Trantas, Emmanouil A.; Baltrus, David A.; Bull, Carolee T.; Wechter, William Patrick; Yan, Shuangchun; Ververidis, Filippos; Almeida, Nalvo F.; Jones, Corbin D.; Dangl, Jeffery L.; Panopoulos, Nickolas J.; Vinatzer, Boris A.; Goumas, Dimitrios E.

2013-01-01

278

Comparative genomics of multiple strains of Pseudomonas cannabina pv. alisalensis, a potential model pathogen of both monocots and dicots.  

PubMed

Comparative genomics of closely related pathogens that differ in host range can provide insights into mechanisms of host-pathogen interactions and host adaptation. Furthermore, sequencing of multiple strains with the same host range reveals information concerning pathogen diversity and the molecular basis of virulence. Here we present a comparative analysis of draft genome sequences for four strains of Pseudomonas cannabina pathovar alisalensis (Pcal), which is pathogenic on a range of monocotyledonous and dicotyledonous plants. These draft genome sequences provide a foundation for understanding host range evolution across the monocot-dicot divide. Like other phytopathogenic pseudomonads, Pcal strains harboured a hrp/hrc gene cluster that codes for a type III secretion system. Phylogenetic analysis based on the hrp/hrc cluster genes/proteins, suggests localized recombination and functional divergence within the hrp/hrc cluster. Despite significant conservation of overall genetic content across Pcal genomes, comparison of type III effector repertoires reinforced previous molecular data suggesting the existence of two distinct lineages within this pathovar. Furthermore, all Pcal strains analyzed harbored two distinct genomic islands predicted to code for type VI secretion systems (T6SSs). While one of these systems was orthologous to known P. syringae T6SSs, the other more closely resembled a T6SS found within P. aeruginosa. In summary, our study provides a foundation to unravel Pcal adaptation to both monocot and dicot hosts and provides genetic insights into the mechanisms underlying pathogenicity. PMID:23555661

Sarris, Panagiotis F; Trantas, Emmanouil A; Baltrus, David A; Bull, Carolee T; Wechter, William Patrick; Yan, Shuangchun; Ververidis, Filippos; Almeida, Nalvo F; Jones, Corbin D; Dangl, Jeffery L; Panopoulos, Nickolas J; Vinatzer, Boris A; Goumas, Dimitrios E

2013-01-01

279

Recognition of Potentially Novel Human Disease-Associated Pathogens by Implementation of Systematic 16S rRNA Gene Sequencing in the Diagnostic Laboratory? †  

PubMed Central

Clinical isolates that are difficult to identify by conventional means form a valuable source of novel human pathogens. We report on a 5-year study based on systematic 16S rRNA gene sequence analysis. We found 60 previously unknown 16S rRNA sequences corresponding to potentially novel bacterial taxa. For 30 of 60 isolates, clinical relevance was evaluated; 18 of the 30 isolates analyzed were considered to be associated with human disease. PMID:20631113

Keller, Peter M.; Rampini, Silvana K.; Büchler, Andrea C.; Eich, Gerhard; Wanner, Roger M.; Speck, Roberto F.; Böttger, Erik C.; Bloemberg, Guido V.

2010-01-01

280

A survey of fungal plant pathogens associated with weed infestations of barberry ( Berberis spp.) in New Zealand and their biocontrol potential  

Microsoft Academic Search

Since the introduction and subsequent naturalisation of five species of Berberis into New Zealand, two species, B. glaucocarpa and B. darwinii have become aggressive invaders of both agricultural and native ecosystems throughout many regions. Both are now targets\\u000a for a biological control program. A survey for pathogens to be used as potential classical or inundative biocontrol agents\\u000a was initiated on

N. W. Waipara; L. A. Smith; A. F. Gianotti; J. P. Wilkie; C. J. Winks; E. H. C. McKenzie

2005-01-01

281

The potential role of arbuscular mycorrhizal (AM) fungi in the bioprotection of plants against soil-borne pathogens in organic and/or other sustainable farming systems.  

PubMed

Sustainable farming systems strive to minimise the use of synthetic pesticides and to optimise the use of alternative management strategies to control soil-borne pathogens. Arbuscular mycorrhizal (AM) fungi are ubiquitous in nature and constitute an integral component of terrestrial ecosystems, forming symbiotic associations with plant root systems of over 80% of all terrestrial plant species, including many agronomically important species. AM fungi are particularly important in organic and/or sustainable farming systems that rely on biological processes rather than agrochemicals to control plant diseases. Of particular importance is the bioprotection conferred to plants against many soil-borne pathogens such as species of Aphanomyces, Cylindrocladium, Fusarium, Macrophomina, Phytophthora, Pythium, Rhizoctonia, Sclerotinium, Verticillium and Thielaviopsis and various nematodes by AM fungal colonisation of the plant root. However, the exact mechanisms by which AM fungal colonisation confers the protective effect are not completely understood, but a greater understanding of these beneficial interactions is necessary for the exploitation of AM fungi within organic and/or sustainable farming systems. In this review, we aim to discuss the potential mechanisms by which AM fungi may contribute to bioprotection against plant soil-borne pathogens. Bioprotection within AM fungal-colonised plants is the outcome of complex interactions between plants, pathogens and AM fungi. The use of molecular tools in the study of these multifaceted interactions may aid the optimisation of the bioprotective responses and their utility within sustainable farming systems. PMID:14971681

Harrier, Lucy A; Watson, Christine A

2004-02-01

282

Cytotoxic Responses and Potential Respiratory Health Effects of Carbon and Carbonaceous Nanoparticulates in the Paso del Norte Airshed Environment  

PubMed Central

We have utilized a range of manufactured or commercial nanoparticulate materials, including surrogate carbon nano-PM along with combustion-generated carbonaceous (soot) nano-PM characteristic of environmental nano-PM (both indoor and outdoor) to investigate and compare their cytotoxic response in vitro with an immortalized human epithelial (lung model) cell line (A549). These have included nano-Ag, Al2O3, TiO2, Fe2O3, ZrO2, Si3N4, chrysotile asbestos, BC, 2 types of MWCNT-aggregate PM (MWCNT-R and MWCNT-N), and high-volume glass fiber collected soots: candle, wood, diesel (truck), tire, and 3-types of natural gas kitchen burner-generated soots: yellow (fuel-rich) flame, low-flow blue flame, and normal flow blue flame soot PM. These carbonaceous nano-PM species can be found in either the indoor and outdoor environments or microenvironments. Two-day and two-week in-vitro cultures of A549 showed cell death (or decreased cell viability) for all nanoparticulate materials, but especially significant for all but the TiO2 and candle, wood, and diesel PM. The natural gas kitchen burner combustion PM cell death response was characteristic of BC and MWCNT PM. There was no correlation with total PAH content of the soot PM. Cytokine release (IL-6, IL-8) was detected for the Ag, Fe2 O3, asbestos, BC and the MWCNT PM. Reactive oxygen species (ROS) production was also detected for Ag, Fe2 O3, ZrO2, asbestos, BC, and the MWCNT aggregate PM, as well as the natural gas kitchen burner combustion PM. TEM, FESEM, and optical microscopy examination of these nanomaterials illustrate the wide range in PM morphologies and crystallinities as well as cell morphologies. Taken together, these results illustrate proinflammatory and related respiratory health issues in relation to environmental nanoparticulates. PMID:18441401

Soto, K. F.; Murr, L. E.; Garza, K. M.

2008-01-01

283

Severe respiratory insufficiency during pandemic H1N1 infection: prognostic value and therapeutic potential of pulmonary surfactant protein A.  

PubMed

For almost two decades, studies have shown collectins to be critical for effective antimicrobial defense of the airways. Members of this protein family, which includes surfactant proteins (SP)-A and D, provide broad-spectrum protection through promoting the aggregation and clearance of pathogens. Interestingly, these proteins may also modulate the immune response, and growing evidence has shown collectins to be protective against several markers of inflammation and injury. In a recent study by Herrera-Ramos and colleagues, genetic variants of collectins were examined in Spanish patients with the pandemic 2009 H1N1 influenza A virus. Comparing genotypes for measures of poor lung function, inflammation, and admission to intensive care, these authors identified three variants of the SP-A gene SFTPA2 that positively correlated with flu severity. Remarkably, they also found the haplotype 1A1 of SFTPA2 to be protective against these indicators, suggesting that targeted therapy with a recombinant form of SP-A2 may improve patient outcome. Although further work is required to confirm the specificity and efficacy of SP-A in therapeutic H1N1 protection, this study is one of the first to suggest a clinical role for SP-A in pandemic influenza. PMID:25184962

Tolosa, Monica; Palaniyar, Nades

2014-08-01

284

CADMIUM AS A RESPIRATORY TOXICANT  

EPA Science Inventory

Cadmium is a major respiratory toxicant as evidenced by numerous human and animal studies. Controlled animal inhalation studies provide supporting evidence to the associations observed in epidemiological studies that Cd has the potential to cause lung fibrosis, emphysema, cancer,...

285

Range-wide genetic population structure of common pochard (Aythya ferina): a potentially important vector of highly pathogenic avian influenza viruses  

PubMed Central

An understanding of the distribution and spatial structure of the natural vectors of zoonothic pathogens is of interest for effective disease control and prevention. Here, we investigate the range-wide population genetic structure of common pochard (Aythya ferina), a long-distance migratory duck and potential vector of highly pathogenic avian influenza. We collected several hundred samples from breeding and wintering grounds across Eurasia including some H5N1-positive individuals and generated partial sequences of the mitochondrial control region and multilocus microsatellite genotypes. Genetic differentiation among breeding populations was significant for both marker types but higher for maternally inherited mtDNA than for biparentally inherited nuclear markers. There was only weak genetic divergence between ducks sampled in Europe and East Asia, and genetic differentiation between populations was not generally associated with geographical distance. No evidence of genetic substructure was detected for ducks sampled on the European wintering grounds. Our results suggest limited breeding-site fidelity, especially in females, but extensive population admixture on the wintering grounds. The specific role of pochards as natural vectors of zoonotic pathogens and in particular H5N1 remains to be clarified but our results point to wintering grounds as potential hotspots for disease transmission. PMID:22393520

Liu, Yang; Keller, Irene; Heckel, Gerald

2011-01-01

286

Transcriptional Response of Mucoid Pseudomonas aeruginosa to Human Respiratory Mucus  

PubMed Central

ABSTRACT Adaptation of bacterial pathogens to a host can lead to the selection and accumulation of specific mutations in their genomes with profound effects on the overall physiology and virulence of the organisms. The opportunistic pathogen Pseudomonas aeruginosa is capable of colonizing the respiratory tract of individuals with cystic fibrosis (CF), where it undergoes evolution to optimize survival as a persistent chronic human colonizer. The transcriptome of a host-adapted, alginate-overproducing isolate from a CF patient was determined following growth of the bacteria in the presence of human respiratory mucus. This stable mucoid strain responded to a number of regulatory inputs from the mucus, resulting in an unexpected repression of alginate production. Mucus in the medium also induced the production of catalases and additional peroxide-detoxifying enzymes and caused reorganization of pathways of energy generation. A specific antibacterial type VI secretion system was also induced in mucus-grown cells. Finally, a group of small regulatory RNAs was identified and a fraction of these were mucus regulated. This report provides a snapshot of responses in a pathogen adapted to a human host through assimilation of regulatory signals from tissues, optimizing its long-term survival potential. PMID:23143799

Cattoir, V.; Narasimhan, G.; Skurnik, D.; Aschard, H.; Roux, D.; Ramphal, R.; Jyot, J.; Lory, S.

2012-01-01

287

Pathogenic Microorganisms in Water  

NSDL National Science Digital Library

Pathogenic Microorganisms in Water: Traditionally, groundwater has been used without treatment because the soil acts as a filter, removing pathogenic microorganisms. Some potential sources of pathogens (or disease causing organisms) in groundwater include septic tanks, leaking sewer lines, sewage sludge, intentional groundwater recharge with sewage, irrigation with sewage, direct injection of sewage, domestic solid waste disposal (landfills) and sewage oxidation ponds. The objective of the session is to introduce hydrogeologist to the types of microorganisms, sources of pathogens, and a simple exercise that can be incorporated into a hydrogeology class.

Melissa Lenczewski

288

Multiplex RT-PCR in the diagnosis of human picornaviruses and human respiratory viruses.  

E-print Network

??The family Picornaviridae includes many human pathogens. Human enteroviruses (HEVs) exhibit a variety of clinical manifestations ranging from poliomyelitis and encephalomyelitis to respiratory infections and… (more)

Jokela, Pia

2012-01-01

289

Inactivation and potential reactivation of pathogenic Escherichia coli O157:H7 in apple juice following ultraviolet light exposure at three monochromatic wavelengths.  

PubMed

Ultraviolet (UV) light irradiation at 254 nm is considered as a novel non-thermal method for decontamination of foodborne pathogenic bacteria. However, lower penetration depth of UV light at 254 nm in apple juice resulted in higher UV dose consumption during apple juice decontamination. In addition, no studies are available on the reactivation of pathogens following exposure to UV light in drinks and beverages. Two novel monochromatic UV light sources (? = 222 and 282 nm) have been developed for bacterial disinfection. However, the inactivation of pathogenic Escherichia coli O157:H7 following exposure to these UV wavelengths is still unclear. Therefore, the present study was conducted to determine the inactivation and reactivation potential of pathogenic E. coli O157:H7 in apple juice following exposure to UV light at three monochromatic wavelengths: Far UV (? = 222 nm), Far UV+ (? = 282 nm) and UVC light (? = 254 nm). The results showed that E. coli O157:H7 is acid-resistant, and up to 99.50% of cells survived in apple juice when incubated at 20 °C for 24 h. Inactivation of E. coli O157:H7 following exposure to Far UV light (2.81 Log reduction) was higher (P < 0.05) than the inactivation caused by UVC light (1.95 Log reduction) and Far UV+ light (1.83 Log reduction) at the similar levels of UV fluence of 75 mJ/cm(2). No any reactivation potential was observed for E. coli O157:H7 in dark incubation phases after exposure to UV light as determined by the regular plating method. In addition, the exposure to Far UV light at 222 nm followed by incubating at 37 °C significantly decreased (P < 0.05) the survival of E. coli O157:H7 during dark incubation phase compared to that of UVC and Far UV+ light. PMID:25475303

Yin, Fugui; Zhu, Yan; Koutchma, Tatiana; Gong, Joshua

2015-04-01

290

METHODOLOGY TO APPORTION AMBIENT AIR MEASUREMENTS TO INVESTIGATE POTENTIAL SHORT-TERM RESPIRATORY EFFECTS NEAR WASTE INCINERATORS  

EPA Science Inventory

Ambient air samples at four sites located near two incinerators (a biomedical waste and a municipal incinerator) in the vicinity of Charlotte, North Carolina were acquired as part of a health effects study that is examining potential, short-term, lung dysfunctions associated with...

291

Genesis of a highly pathogenic and potentially pandemic H5N1 influenza virus in eastern Asia  

Microsoft Academic Search

A highly pathogenic avian influenza virus, H5N1, caused disease outbreaks in poultry in China and seven other east Asian countries between late 2003 and early 2004; the same virus was fatal to humans in Thailand and Vietnam. Here we demonstrate a series of genetic reassortment events traceable to the precursor of the H5N1 viruses that caused the initial human outbreak

K. S. Li; Y. Guan; J. Wang; G. J. D. Smith; K. M. Xu; L. Duan; A. P. Rahardjo; P. Puthavathana; C. Buranathai; T. D. Nguyen; A. T. S. Estoepangestie; A. Chaisingh; P. Auewarakul; H. T. Long; N. T. H. Hanh; R. J. Webby; L. L. M. Poon; H. Chen; K. F. Shortridge; K. Y. Yuen; R. G. Webster; J. S. M. Peiris

2004-01-01

292

A survey of rodent-borne pathogens carried by wild-caught Norway rats: a potential threat to laboratory rodent colonies.  

PubMed

Unintentional infection of laboratory rodents can compromise scientific research as well as the health of the animals and animal handlers. The source of contamination often is unknown, but may be introduced by wild rats from surrounding environments. To determine whether rats in Baltimore, Maryland, USA carry infectious agents commonly found in laboratory rodent colonies, we live-trapped 162 rats during 2005 to 2006 and screened them for a panel of viruses, bacteria and parasites. Antibodies against rat coronavirus/sialodacryoadenitis virus (91.7%), Mycoplasma pulmonis (72.9%), cilia-associated respiratory bacillus (52.1%), rat parvovirus/rat minute virus (29.2%), Kilham rat virus (10.4%), Toolan's H-1 virus (10.4%), Sendai virus (4.2%) and Theiler's mouse encephalomyelitis virus (4.2%), were detected in wild-caught Norway rats. Antibodies against reovirus and pneumonia virus of mice were not detected in wild Norway rats. Endoparasites, including Nippostrongylus braziliensis (71.6%), Rodentolepis nana or Hymenolepis diminuta (34.4%), Hetarakis spumosa (24.1%) and Trichuris muris (14.8%), as well as ectoparasites (14.8%), were identified in wild-caught rats. The risk of pathogen transmission from wild-caught rats to laboratory colonies needs to be mitigated by minimizing exposures rather than assuming wild animals represent a minimal hazard. PMID:18348770

Easterbrook, Judith D; Kaplan, J B; Glass, G E; Watson, J; Klein, S L

2008-01-01

293

Full-genome analysis of a canine pneumovirus causing acute respiratory disease in dogs, Italy.  

PubMed

An outbreak of canine infectious respiratory disease (CIRD) associated to canine pneumovirus (CnPnV) infection is reported. The outbreak occurred in a shelter of the Apulia region and involved 37 out of 350 dogs that displayed cough and/or nasal discharge with no evidence of fever. The full-genomic characterisation showed that the causative agent (strain Bari/100-12) was closely related to CnPnVs that have been recently isolated in the USA, as well as to murine pneumovirus, which is responsible for respiratory disease in mice. The present study represents a useful contribution to the knowledge of the pathogenic potential of CnPnV and its association with CIRD in dogs. Further studies will elucidate the pathogenicity and epidemiology of this novel pneumovirus, thus addressing the eventual need for specific vaccines. PMID:24400129

Decaro, Nicola; Pinto, Pierfrancesco; Mari, Viviana; Elia, Gabriella; Larocca, Vittorio; Camero, Michele; Terio, Valentina; Losurdo, Michele; Martella, Vito; Buonavoglia, Canio

2014-01-01

294

Full-Genome Analysis of a Canine Pneumovirus Causing Acute Respiratory Disease in Dogs, Italy  

PubMed Central

An outbreak of canine infectious respiratory disease (CIRD) associated to canine pneumovirus (CnPnV) infection is reported. The outbreak occurred in a shelter of the Apulia region and involved 37 out of 350 dogs that displayed cough and/or nasal discharge with no evidence of fever. The full-genomic characterisation showed that the causative agent (strain Bari/100-12) was closely related to CnPnVs that have been recently isolated in the USA, as well as to murine pneumovirus, which is responsible for respiratory disease in mice. The present study represents a useful contribution to the knowledge of the pathogenic potential of CnPnV and its association with CIRD in dogs. Further studies will elucidate the pathogenicity and epidemiology of this novel pneumovirus, thus addressing the eventual need for specific vaccines. PMID:24400129

Decaro, Nicola; Pinto, Pierfrancesco; Mari, Viviana; Elia, Gabriella; Larocca, Vittorio; Camero, Michele; Terio, Valentina; Losurdo, Michele; Martella, Vito; Buonavoglia, Canio

2014-01-01

295

Virion packaging of multiple cleavage isoforms of porcine reproductive and respiratory syndrome virus nonstructural protein 2  

Technology Transfer Automated Retrieval System (TEKTRAN)

Porcine reproductive and respiratory syndrome virus (PRRSV) is the cause of a complex disease often resulting in significant morbidity and mortality. Recently, highly pathogenic isolates have emerged which have proven to be devastatingly effective pathogens, resulting in rapid systemic deterioration...

296

A Prospective Study of Agents Associated with Acute Respiratory Infection among Young American Indian Children  

PubMed Central

Background Native American children have higher rates of morbidity associated with acute respiratory infection than children in the general United States population, yet detailed information is lacking regarding their principal clinical presentations and infectious etiologies. Methods We pursued a comprehensive molecular survey of bacteria and viruses in nasal wash specimens from children with acute respiratory disease collected prospectively over one year (January 1 through December 31, 2009) from 915 Navajo and White Mountain Apache children in their second or third year of life who had been enrolled in an efficacy study of an RSV monoclonal antibody in the first year of life. Results During the surveillance period, 1476 episodes of disease were detected in 669 children. Rates of outpatient and inpatient lower respiratory tract illness were 391 and 79 per 1000 child-years, respectively, and were most commonly diagnosed as pneumonia. Potential pathogens were detected in 88% of specimens. Viruses most commonly detected were respiratory syncytial virus (RSV) and human rhinovirus (HRV); 2009 pandemic influenza A (H1N1) illnesses primarily occurred in the fall. Streptococcus pneumoniae was detected in 60% of subjects; only HRV was significantly associated with S. pneumoniae carriage. The presence of influenza virus, HRV, or S. pneumoniae was not associated with increased risk for lower respiratory tract involvement or hospitalization. Conclusions Acute lower respiratory illnesses occur at disproportionately high rates among young American Indian children, and are associated with a range of common pathogens. This study provides critical evidence to support reducing the disproportionate burden of acute respiratory disease among young Native Americans. PMID:23470677

Bhat, Niranjan; Tokarz, Rafal; Jain, Komal; Haq, Saddef; Weatherholtz, Robert; Chandran, Aruna; Karron, Ruth; Reid, Raymond; Santosham, Mathuram; O’Brien, Katherine L.; Lipkin, W. Ian

2013-01-01

297

Effectiveness of serum megakaryocyte potentiating factor in evaluating the effects of chrysotile and its heated products on respiratory organs  

Microsoft Academic Search

Chrysotile (CH), the most common form of asbestos, is rendered less toxic by heating it at 1000°C and converting it to forsterite (FO-1000). However, further safety tests are needed to evaluate human health risk of these materials. It has been reported that serum concentrations of megakaryocyte potentiating factor N-ERC\\/mesothelin become elevated in patients with mesotheliomas caused by asbestos exposure. In

Ayako Takata; Hiroshi Yamauchi; Tadao Toya; Sayako Miyamoto-Kohno; Yuka Iwatatsu; Iroha Teranaka; Masahito Aminaka; Kiyotsugu Yamashita; Norihiko Kohyama

2011-01-01

298

Pulsing of Membrane Potential in Individual Mitochondria: A Stress-Induced Mechanism to Regulate Respiratory Bioenergetics in Arabidopsis[W  

PubMed Central

Mitochondrial ATP synthesis is driven by a membrane potential across the inner mitochondrial membrane; this potential is generated by the proton-pumping electron transport chain. A balance between proton pumping and dissipation of the proton gradient by ATP-synthase is critical to avoid formation of excessive reactive oxygen species due to overreduction of the electron transport chain. Here, we report a mechanism that regulates bioenergetic balance in individual mitochondria: a transient partial depolarization of the inner membrane. Single mitochondria in living Arabidopsis thaliana root cells undergo sporadic rapid cycles of partial dissipation and restoration of membrane potential, as observed by real-time monitoring of the fluorescence of the lipophilic cationic dye tetramethyl rhodamine methyl ester. Pulsing is induced in tissues challenged by high temperature, H2O2, or cadmium. Pulses were coincident with a pronounced transient alkalinization of the matrix and are therefore not caused by uncoupling protein or by the opening of a nonspecific channel, which would lead to matrix acidification. Instead, a pulse is the result of Ca2+ influx, which was observed coincident with pulsing; moreover, inhibitors of calcium transport reduced pulsing. We propose a role for pulsing as a transient uncoupling mechanism to counteract mitochondrial dysfunction and reactive oxygen species production. PMID:22395486

Schwarzländer, Markus; Logan, David C.; Johnston, Iain G.; Jones, Nick S.; Meyer, Andreas J.; Fricker, Mark D.; Sweetlove, Lee J.

2012-01-01

299

Expression of the beta-glucan receptor, Dectin-1, on murine leukocytes in situ correlates with its function in pathogen recognition and reveals potential roles in leukocyte interactions.  

PubMed

Dectin-1 is a pathogen-recognition receptor on macrophages (MPhis), neutrophils, and dendritic cells (DCs). On MPhis and bone marrow-derived DCs, it has been shown to mediate the nonopsonic recognition of and response to soluble and particulate yeast beta-glucans. We have optimized the immunohistochemical detection of Dectin-1 and demonstrated its expression on neutrophils, subpopulations of MPhis in splenic red and white pulp, alveolar MPhis, Kupffer cells, and MPhis and DCs in the lamina propria of gut villi. This is consistent with its role in pathogen surveillance. A significant proportion of CD11c(+) splenic DCs expressed Dectin-1, but expression was not restricted to any one subset. Dectin-1 expression was low on resident MPhis and DCs of skin and was not detected on resident MPhis or DCs in kidney, heart, brain, or eye. The proposed, additional role of Dectin-1 as a coreceptor for T cell activation is supported by its expression on DCs in the T cell areas of the spleen and lymph nodes. Strong expression of Dectin-1 on subpopulations of MPhis and DCs in the medullary and corticomedullary regions of the thymus suggests a role distinct from pathogen recognition. Tissue localization thus revealed potential roles of Dectin-1 in leukocyte interactions during innate immune responses and T cell development. PMID:15107454

Reid, Delyth M; Montoya, Maria; Taylor, Philip R; Borrow, Persephone; Gordon, Siamon; Brown, Gordon D; Wong, Simon Y C

2004-07-01

300

Respiratory Distress  

NASA Technical Reports Server (NTRS)

The University of Miami School of Medicine asked the Research Triangle Institute for assistance in improvising the negative pressure technique to relieve respiratory distress in infants. Marshall Space Flight Center and Johnson Space Center engineers adapted this idea to the lower-body negative-pressure system seals used during the Skylab missions. Some 20,000 babies succumb to respiratory distress in the U.S. each year, a condition in which lungs progressively lose their ability to oxygenate blood. Both positive and negative pressure techniques have been used - the first to force air into lungs, the second to keep infant's lungs expanded. Negative pressure around chest helps the baby expand his lungs and maintain proper volume of air. If doctors can keep the infant alive for four days, the missing substance in the lungs will usually form in sufficient quantity to permit normal breathing. The Skylab chamber and its leakproof seals were adapted for medical use.

1976-01-01

301

Grain dust originating from organic and conventional farming as a potential source of biological agents causing respiratory diseases in farmers  

PubMed Central

Introduction Agricultural producers are exposed to a number of different health risks associated with their work environment. Aim The objective of the study was to assess the degree of colonization by fungi in terms of quantity and in terms of variety of species the samples taken from the settled dust from combine threshing of rye cultivation from organic and conventional farms in the Province of Lublin. Material and methods This paper is a preliminary quantitative assessment of the species of fungi colonizing the samples of settled dust collected during combine threshing from organic and conventional farms in the Province of Lublin. One of the stages of the project was the classification of biosafety BSL (biosafety level) of selected isolates and API ZYM tests to evaluate the potential ability of isolates to cause adverse health effects. To determine the concentration and composition of fungi in collected samples plate dilution method was used with two media: Malt Agar and Potato Dextrose Agar. Results Most commonly isolated fungi in settled dust samples collected during combine threshing from organic farms, on PDA medium were: Alternaria alternata and Aureobasidium pullulans. Cultures on MA medium were dominated by Alternaria alternata, Mycelia sterilia and Fusarium poae. In samples of dust from conventional crops, the predominant species was Alternaria alternata on PDA medium and on MA medium. Conclusions The obtained results show a potential risk of people involved in agricultural work. PMID:24493998

Cholewa, Gra?yna; Krasowska, Ewelina; Chmielewska-Badora, Jolanta; Zwoli?ski, Jacek; Sobczak, Pawe?

2013-01-01

302

Regulation of mitochondrial respiratory chain structure and function by estrogens/estrogen receptors and potential physiological/pathophysiological implications.  

PubMed

It is well known that the biological and carcinogenic effects of 17beta-estradiol (E2) are mediated via nuclear estrogen receptors (ERs) by regulating nuclear gene expression. Several rapid, non-nuclear genomic effects of E2 are mediated via plasma membrane-bound ERs. In addition, there is accumulating evidence suggesting that mitochondria are also important targets for the action of estrogens and ERs. This review summarized the studies on the effects of estrogens via ERs on mitochondrial structure and function. The potential physiological and pathophysiological implications of deficiency and/or overabundance of these E2/ER-mediated mitochondrial effects in stimulation of cell proliferation, inhibition of apoptosis, E2-mediated cardiovascular and neuroprotective effects in target cells are also discussed. PMID:16169101

Chen, Jin-Qiang; Yager, James D; Russo, Jose

2005-10-30

303

EXPERIMENTAL INFECTION OF THE RESPIRATORY TRACT WITH MYCOPLASMA PNEUMONIAE  

EPA Science Inventory

Mycoplasma pneumoniae, a common human respiratory pathogen, has been studied experimentally for years using intranasal inoculation of the golden Sytrian hamster. Because of recent evidence outlining the role in pulmonary immune development of particle size and depth of mycoplasma...

304

Potential Role for Telavancin in Bacteremic Infections Due to Gram-Positive Pathogens: Focus on Staphylococcus aureus.  

PubMed

Staphylococcus aureus bacteremia (SAB) is one of the most common serious bacterial infections and the most frequent invasive infection due to methicillin-resistant S. aureus (MRSA). Treatment is challenging, particularly for MRSA, because of limited treatment options. Telavancin is a bactericidal lipoglycopeptide antibiotic that is active against a range of clinically relevant gram-positive pathogens including MRSA. In experimental animal models of sepsis telavancin was shown to be more effective than vancomycin. In clinically evaluable patients enrolled in a pilot study of uncomplicated SAB, cure rates were 88% for telavancin and 89% for standard therapy. Among patients with infection due to only gram-positive pathogens enrolled in the 2 phase 3 studies of telavancin for treatment of hospital-acquired pneumonia, cure rates for those with bacteremic S. aureus pneumonia were 41% (9/22, telavancin) and 40% (10/25, vancomycin) with identical mortality rates. These data support further evaluation of telavancin in larger, prospective studies of SAB. PMID:25472944

Corey, G Ralph; Rubinstein, Ethan; Stryjewski, Martin E; Bassetti, Matteo; Barriere, Steven L

2015-03-01

305

Epidemiology and identification of potential fungal pathogens causing invasive fungal infections in a tertiary care hospital in northeast Thailand.  

PubMed

Invasive fungal infections (IFIs) are life threatening and associated with a high mortality rate. Here, we describe the distribution of pathogens, host risk factors, and significance of fungi isolated from patients with IFIs. The study included 861 fungal isolates recovered between 2006 and 2011 from 802 patients at Srinagarind Hospital, Thailand. Based on the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group 2008 criteria, 28.5% (245/861 isolates) of the fungal isolates were considered to be causative agents of IFIs. The most common fungus was Candida albicans (46%, 396/861 isolates). However, the most common yeast causing IFIs was Cryptococcus neoformans (34.7%, 85/245 isolates), while the most common mould was Penicillium marneffei (10.6%, 26/245 isolates). Cryptococcosis was significantly associated with human immunodeficiency virus infections (P < 0.001). Trend analysis revealed that there was no significant increase in IFI cases (P = 0.34) from 2006 to 2011 or from 2007 to 2011 (P = 0.05), but there was a trend toward significant increases in candidiasis (P = 0.04). The fungal isolates were categorized according to the positive predictive value of their recovery in cultures as being true (>95%), moderate (5%-95%), and rare (<5%) pathogens. This classification system could facilitate the prediction of the likelihood of diseases caused by the isolated fungi. PMID:25231771

Faksri, Kiatichai; Kaewkes, Wanlop; Chaicumpar, Kunyaluk; Chaimanee, Prajuab; Wongwajana, Suwin

2014-11-01

306

Tetrahydrocannabinol Induces Brain Mitochondrial Respiratory Chain Dysfunction and Increases Oxidative Stress: A Potential Mechanism Involved in Cannabis-Related Stroke  

PubMed Central

Cannabis has potential therapeutic use but tetrahydrocannabinol (THC), its main psychoactive component, appears as a risk factor for ischemic stroke in young adults. We therefore evaluate the effects of THC on brain mitochondrial function and oxidative stress, key factors involved in stroke. Maximal oxidative capacities Vmax (complexes I, III, and IV activities), Vsucc (complexes II, III, and IV activities), Vtmpd (complex IV activity), together with mitochondrial coupling (Vmax/V0), were determined in control conditions and after exposure to THC in isolated mitochondria extracted from rat brain, using differential centrifugations. Oxidative stress was also assessed through hydrogen peroxide (H2O2) production, measured with Amplex Red. THC significantly decreased Vmax (?71%; P < 0.0001), Vsucc (?65%; P < 0.0001), and Vtmpd (?3.5%; P < 0.001). Mitochondrial coupling (Vmax/V0) was also significantly decreased after THC exposure (1.8±0.2 versus 6.3±0.7; P < 0.001). Furthermore, THC significantly enhanced H2O2 production by cerebral mitochondria (+171%; P < 0.05) and mitochondrial free radical leak was increased from 0.01±0.01 to 0.10±0.01% (P < 0.001). Thus, THC increases oxidative stress and induces cerebral mitochondrial dysfunction. This mechanism may be involved in young cannabis users who develop ischemic stroke since THC might increase patient's vulnerability to stroke. PMID:25654095

Wolff, Valérie; Schlagowski, Anna-Isabel; Rouyer, Olivier; Charles, Anne-Laure; Singh, François; Auger, Cyril; Schini-Kerth, Valérie; Marescaux, Christian; Raul, Jean-Sébastien; Zoll, Joffrey; Geny, Bernard

2015-01-01

307

Characterization of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) spike glycoprotein-mediated viral entry  

Microsoft Academic Search

Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) is a rapidly emerging pathogen with potentially serious consequences for public health. Here we describe conditions that result not only in the efficient expression of the SARS-CoV spike (S) protein on the surface of cells, but in its incorporation into lentiviral particles that can be used to transduce cells in an S glycoprotein-dependent manner.

Graham Simmons; Jacqueline D. Reeves; Andrew J. Rennekamp; Sean M. Amberg; Andrew J. Piefer; Paul Bates

2004-01-01

308

Anti-adherence potential of Enterococcus durans cells and its cell-free supernatant on plastic and stainless steel against foodborne pathogens.  

PubMed

It is demonstrated that numerous bacteria are able to attach to surfaces of equipment used for food handling or processing. In this study, a strain of Enterococcus durans, originally isolated from a milking machine surface, was firstly studied for its biofilm formation potential on plastic and stainless steel supports. The strain was found to be a biofilm producer either at 25, 30 or 37 °C on polystyrene microtitre plates, with a best adherence level observed at 25 °C. En. durans showed a strong adhesion to stainless steel AISI-304. Antibacterial and anti-adherence activities of En. durans were tested against four foodborne pathogens (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853 and Listeria innocua CLIP 74915) which were shown as biofilm producers on both plastic and stainless steel. En. durans cells and cell-free culture supernatant showed a significant (P?potential of the pathogens either on solid media or in broth co-cultures. Characterization of the antibacterial substances indicated their proteinaceous nature which assigned them most probably to bacteriocins group. PMID:25466409

Amel, Ait Meddour; Farida, Bendali; Djamila, Sadoun

2014-12-01

309

Pathogenic Potential of Two Sibling Species, Anisakis simplex (s.s.) and Anisakis pegreffii (Nematoda: Anisakidae): In Vitro and In Vivo Studies  

PubMed Central

The pathogenic potentials of two sibling nematodes Anisakis simplex sensu stricto (s.s.) and A. pegreffii were compared by in vitro and in vivo studies. Live third-stage larvae of each species were subjected to agar blocks made using PBS or RPMI-1640, overlaid with different supernatants (artificial gastric juice, PBS, and RPMI-1640), and their penetration ability was compared. Their tolerance of artificial gastric juice was also tested. Further, they were introduced into rats by gastric intubation, and the in vivo locations of them were investigated. A. pegreffii showed higher penetration ability than A. simplex (s.s.) in most of the experimental conditions, except for the RPMI-1640 agar block overlaid with artificial gastric juice. In an acid tolerance test, the mean survival times were 6.1 days for A. simplex (s.s.) and 4.2 days for A. pegreffii. In an animal experiment, A. simplex (s.s.) stayed for a shorter time in the stomachs of rats than A. pegreffii. Some A. pegreffii and A. simplex (s.s.) were embedded in the gastric mucosa or freely existed in the abdominal cavity. All of these results suggest that A. pegreffii has the pathogenic potential to cause anisakidosis in humans when ingested, as does A. simplex (s.s.).

Jeon, Chan-Hyeok; Kim, Jeong-Ho

2015-01-01

310

Rapid laboratory diagnosis for respiratory infectious diseases by using MALDI-TOF mass spectrometry  

PubMed Central

It is still challenging to prevent and treat respiratory infectious diseases. One critical step in the successful treatment of respiratory infections is rapid diagnosis by identifying the causative microorganisms in a timely fashion. However, traditional methods for identification of causative agents could not satisfy the need for rapid and accurate testing due to the limitations of technology-used. In recent years, matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) has been validated and used for rapid identification of microorganism and for potential discovery of diseases associated biomarkers. We reviewed recent advances of MALDI-TOF-MS as the laboratory diagnostic tool for the rapid laboratory diagnosis of microorganisms associated with respiratory infectious diseases, with the focus on rapid identification of pathogenic bacteria and molecular markers discovery using MALDI-TOF-MS. With the advanced technologies such as MALDI-TOF, early and targeted therapies based on rapid identification of pathogens and could lead to quick and effective treatment of respiratory infections and better patient management. PMID:24822111

Fu, Jianfeng

2014-01-01

311

Human Pathogens Abundant in the Bacterial Metagenome of Cigarettes  

PubMed Central

Background Many studies have evaluated chemical, heavy metal, and other abiotic substances present in cigarettes and their roles in the development of lung cancer and other diseases, yet no studies have comprehensively evaluated bacterial diversity of cigarettes and the possible impacts of these microbes on respiratory illnesses in smokers and exposed nonsmokers. Objectives The goal of this study was to explore the bacterial metagenomes of commercially available cigarettes. Methods A 16S rRNA-based taxonomic microarray and cloning and sequencing were used to evaluate total bacterial diversity of four brands of cigarettes. Normalized microarray data were compared using principal component analysis and hierarchical cluster analysis to evaluate potential differences in microbial diversity across cigarette brands. Results Fifteen different classes of bacteria and a broad range of potentially pathogenic organisms were detected in all cigarette samples. Most notably, we detected Acinetobacter, Bacillus, Burkholderia, Clostridium, Klebsiella, Pseudomonas aeruginosa, and Serratia in ? 90% of all cigarette samples. Other pathogenic bacteria detected included Campylobacter, Enterococcus, Proteus, and Staphylococcus. No significant variability in bacterial diversity was observed across the four different cigarette brands. Conclusions Previous studies have shown that smoking is associated with colonization by pathogenic bacteria and an increased risk of lung infections. However, this is the first study to show that cigarettes themselves could be the direct source of exposure to a wide array of potentially pathogenic microbes among smokers and other people exposed to secondhand smoke. The overall public health implications of these findings are unclear at this time, and future studies are necessary to determine whether bacteria in cigarettes could play important roles in the development of both infectious and chronic respiratory diseases. PMID:20064769

Sapkota, Amy R.; Berger, Sibel; Vogel, Timothy M.

2010-01-01

312

Biosecurity and Vector Behaviour: Evaluating the Potential Threat Posed by Anglers and Canoeists as Pathways for the Spread of Invasive Non-Native Species and Pathogens  

PubMed Central

Invasive non-native species (INNS) endanger native biodiversity and are a major economic problem. The management of pathways to prevent their introduction and establishment is a key target in the Convention on Biological Diversity's Aichi biodiversity targets for 2020. Freshwater environments are particularly susceptible to invasions as they are exposed to multiple introduction pathways, including non-native fish stocking and the release of boat ballast water. Since many freshwater INNS and aquatic pathogens can survive for several days in damp environments, there is potential for transport between water catchments on the equipment used by recreational anglers and canoeists. To quantify this biosecurity risk, we conducted an online questionnaire with 960 anglers and 599 canoeists to investigate their locations of activity, equipment used, and how frequently equipment was cleaned and/or dried after use. Anglers were also asked about their use and disposal of live bait. Our results indicate that 64% of anglers and 78.5% of canoeists use their equipment/boat in more than one catchment within a fortnight, the survival time of many of the INNS and pathogens considered in this study and that 12% of anglers and 50% of canoeists do so without either cleaning or drying their kit between uses. Furthermore, 8% of anglers and 28% of canoeists had used their equipment overseas without cleaning or drying it after each use which could facilitate both the introduction and secondary spread of INNS in the UK. Our results provide a baseline against which to evaluate the effectiveness of future biosecurity awareness campaigns, and identify groups to target with biosecurity awareness information. Our results also indicate that the biosecurity practices of these groups must improve to reduce the likelihood of inadvertently spreading INNS and pathogens through these activities. PMID:24717714

Anderson, Lucy G.; White, Piran C. L.; Stebbing, Paul D.; Stentiford, Grant D.; Dunn, Alison M.

2014-01-01

313

Biosecurity and vector behaviour: evaluating the potential threat posed by anglers and canoeists as pathways for the spread of invasive non-native species and pathogens.  

PubMed

Invasive non-native species (INNS) endanger native biodiversity and are a major economic problem. The management of pathways to prevent their introduction and establishment is a key target in the Convention on Biological Diversity's Aichi biodiversity targets for 2020. Freshwater environments are particularly susceptible to invasions as they are exposed to multiple introduction pathways, including non-native fish stocking and the release of boat ballast water. Since many freshwater INNS and aquatic pathogens can survive for several days in damp environments, there is potential for transport between water catchments on the equipment used by recreational anglers and canoeists. To quantify this biosecurity risk, we conducted an online questionnaire with 960 anglers and 599 canoeists to investigate their locations of activity, equipment used, and how frequently equipment was cleaned and/or dried after use. Anglers were also asked about their use and disposal of live bait. Our results indicate that 64% of anglers and 78.5% of canoeists use their equipment/boat in more than one catchment within a fortnight, the survival time of many of the INNS and pathogens considered in this study and that 12% of anglers and 50% of canoeists do so without either cleaning or drying their kit between uses. Furthermore, 8% of anglers and 28% of canoeists had used their equipment overseas without cleaning or drying it after each use which could facilitate both the introduction and secondary spread of INNS in the UK. Our results provide a baseline against which to evaluate the effectiveness of future biosecurity awareness campaigns, and identify groups to target with biosecurity awareness information. Our results also indicate that the biosecurity practices of these groups must improve to reduce the likelihood of inadvertently spreading INNS and pathogens through these activities. PMID:24717714

Anderson, Lucy G; White, Piran C L; Stebbing, Paul D; Stentiford, Grant D; Dunn, Alison M

2014-01-01

314

Respiratory Distress Syndrome  

MedlinePLUS

... page from the NHLBI on Twitter. What Is Respiratory Distress Syndrome? Respiratory distress syndrome (RDS) is a breathing disorder that ... damage. Rate This Content: Next >> January 24, 2012 Respiratory Distress Syndrome Clinical Trials Clinical trials are research ...

315

Respiratory infections: a current and future threat.  

PubMed

Despite all the medical progress in the last 50 years pulmonary infections continue to exact and extremely high human and economic cost. This review will focus on the human, pathogen and environmental factors that contribute to the continued global burden or respiratory diseases with a particular focus on areas where we might hope to see some progress in the coming decades. PMID:19659646

Waterer, Grant; Wunderink, Richard

2009-07-01

316

EGFR activation suppresses respiratory virus-induced IRF1-dependent CXCL10 production.  

PubMed

Airway epithelial cells are the primary cell type involved in respiratory viral infection. Upon infection, airway epithelium plays a critical role in host defense against viral infection by contributing to innate and adaptive immune responses. Influenza A virus, rhinovirus, and respiratory syncytial virus (RSV) represent a broad range of human viral pathogens that cause viral pneumonia and induce exacerbations of asthma and chronic obstructive pulmonary disease. These respiratory viruses induce airway epithelial production of IL-8, which involves epidermal growth factor receptor (EGFR) activation. EGFR activation involves an integrated signaling pathway that includes NADPH oxidase activation of metalloproteinase, and EGFR proligand release that activates EGFR. Because respiratory viruses have been shown to activate EGFR via this signaling pathway in airway epithelium, we investigated the effect of virus-induced EGFR activation on airway epithelial antiviral responses. CXCL10, a chemokine produced by airway epithelial cells in response to respiratory viral infection, contributes to the recruitment of lymphocytes to target and kill virus-infected cells. While respiratory viruses activate EGFR, the interaction between CXCL10 and EGFR signaling pathways is unclear, and the potential for EGFR signaling to suppress CXCL10 has not been explored. Here, we report that respiratory virus-induced EGFR activation suppresses CXCL10 production. We found that influenza virus-, rhinovirus-, and RSV-induced EGFR activation suppressed IFN regulatory factor (IRF) 1-dependent CXCL10 production. In addition, inhibition of EGFR during viral infection augmented IRF1 and CXCL10. These findings describe a novel mechanism that viruses use to suppress endogenous antiviral defenses, and provide potential targets for future therapies. PMID:24838750

Kalinowski, April; Ueki, Iris; Min-Oo, Gundula; Ballon-Landa, Eric; Knoff, David; Galen, Benjamin; Lanier, Lewis L; Nadel, Jay A; Koff, Jonathan L

2014-07-15

317

Oxidized Fatty Acids: A Potential Pathogenic Link Between Fatty Liver and Type 2 Diabetes in Obese Adolescents?  

PubMed Central

Abstract In this study, we sought to investigate the putative association of the oxidized metabolites derived from linoleic acid (OXFAs) with pediatric nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes (T2D). We studied 80 obese adolescents (age 13.3±3.31 years; body mass index 33.0±6.79?kg/m2), who underwent an oral glucose tolerance test, a magnetic resonance imaging (MRI) to measure the hepatic fat content, and the measurement of OXFAs and caspase-cleaved Citokeratin18 fragment (CK-18), a robust biomarker of liver injury. In this study, we show that only in subjects with hepatic steatosis, the OXFAs are associated with the CK-18 and that this association is modulated by the PNPLA3 rs738409 variant. We also show that most of the OXFAs are associated with a lower insulin secretion and that adolescents with T2D have higher levels of OXFAs than subjects with impaired or normal glucose tolerance. These observations lead to the hypothesis that the OXFAs may be the pathogenic link between liver injury and T2D and that the novel therapeutic opportunities targeting the OXFAs are possible in adolescents with early-onset NAFLD and T2D. Antioxid. Redox Signal. 20, 383–389. PMID:23815500

Caprio, Sonia; Giannini, Cosimo; Kim, Grace; Kursawe, Romy; Pierpont, Bridget; Shaw, Melissa M.; Feldstein, Ariel E.

2014-01-01

318

Potential new sources of wheat curl mite resistance in wheat to prevent the spread of yield-reducing pathogens.  

PubMed

The wheat curl mite (WCM), Aceria tosichella Keifer (Trombidiformes: Eriophyidae), is a major pest in cropping regions of the world and is recognised as the primary vector of several yield-reducing pathogens, primarily affecting wheat. Management of WCM is complicated due to several aspects of the mite's biology and ecology; however, commercially viable mite resistant wheat varieties may offer practical long-term management options. Unfortunately, mite populations have adapted to previously identified sources of resistance, highlighting the need for further sources of resistance and the value of stacking different resistances to give greater degrees and longevity of control. In this study we assessed the susceptibility of 42 wheat-derived genotypes to mite population growth using a new experimental method that overcomes methodological limitations of previous studies. Experimental wheat lines included a variety of wheat genotypes, related Triticeae species, wheat-alien chromosome amphiploids, and chromosome addition or substitution lines. From these we identify new promising sources of WCM resistance associated with Thinopyrum intermedium, Th. ponticum and Hordeum marinum chromosomes. More specifically we identify group 1J and 5J chromosomes of the L3 and L5 wheat-Th. intermedium addition lines as new sources of resistance that could be exploited to transfer resistance onto homoeologous wheat chromosomes. This study offers new methods for reliable in situ estimations of mite abundance on cereal plants, and new sources of WCM resistance that may assist management of WCM and associated viruses in wheat. PMID:24705793

Richardson, Kelly; Miller, Adam D; Hoffmann, Ary A; Larkin, Philip

2014-09-01

319

Re-identification of Aeromonas isolates from chironomid egg masses as the potential pathogenic bacteria Aeromonas aquariorum.  

PubMed

Egg masses of the non-biting midge Chironomous sp. have recently been found to serve as a reservoir for Vibrio cholerae and Aeromonas species. These insects are widely distributed in freshwater and evidence suggests that they may disseminate pathogenic bacteria species into drinking water systems. In the current study the taxonomy of 26 Aeromonas isolates, previously recovered from chironomid egg masses, was re-evaluated. It was found that 23 isolates, which had previously been identified as Aeromonas caviae, could belong to the recently described species Aeromonas aquariorum by their biochemical traits. To date, A. aquariorum has been found in ornamental fish and also in human extra-intestinal infections. ERIC-PCR genotyping differentiated 11 strains within the 23 A. aquariorum isolates, whose identity was confirmed by their rpoD gene sequences. Strains were found to possess the following virulence-associated genes: alt (90.9%), ahpB (81.8%), pla/lip/lipH3/apl-1/lip (54.5%), fla (27.3%), act/hylA/aerA (27.3%), ascF-ascG (81.8%) and aexT (9%) encoding for the cytotonic heat-labile enterotoxin, elastase, lipase, flagella, cytotoxic enterotoxins, the Type III Secretion System and the AexT toxin delivered by this system respectively. These findings indicate that chironomid egg masses harbour strains of A. aquariorum, which bear an important number of virulence genes, and that this species was misidentified originally as A. caviae. PMID:23761256

Figueras, Maria José; Beaz-Hidalgo, Roxana; Senderovich, Yigal; Laviad, Sivan; Halpern, Malka

2011-04-01

320

Design of potential RNAi (miRNA and siRNA) molecules for Middle East respiratory syndrome coronavirus (MERS-CoV) gene silencing by computational method.  

PubMed

The Middle East respiratory syndrome coronavirus (MERS-CoV) is a virus that manifests itself in viral infection with fever, cough, shortness of breath, renal failure and severe acute pneumonia, which often result in a fatal outcome. MERS-CoV has been shown to spread between people who are in close contact. Transmission from infected patients to healthcare personnel has also been observed and is irredeemable with present technology. Genetic studies on MERS-CoV have shown that ORF 1ab encodes replicase polyproteins and play a foremost role in viral infection. Therefore, ORF 1ab replicase polyprotein may be used as suitable target for disease control. Viral activity can be controlled by RNA interference (RNAi) technology, a leading method for post transcriptional gene silencing in a sequence specific manner. However, there is a genetic inconsistency in different viral isolates; it is a great challenge to design potential RNAi (miRNA and siRNA) molecules which can silence the respective target genes rather than any other viral gene simultaneously. In current study four effective miRNA and five siRNA molecules for silencing of nine different strains of MERS-CoV were rationally designed and corroborated using computational methods, which might lead to knockdown the activity of virus. siRNA and miRNA molecules were predicted against ORF1ab gene of different strains of MERS-CoV as effective candidate using computational methods. Thus, this method may provide an insight for the chemical synthesis of antiviral RNA molecule for the treatment of MERS-CoV, at genomic level. PMID:25373633

Nur, Suza Mohammad; Hasan, Md Anayet; Amin, Mohammad Al; Hossain, Mehjabeen; Sharmin, Tahmina

2014-11-01

321

HOST-PARASITE AND GENOTYPE-BY-ENVIRONMENT INTERACTIONS: TEMPERATURE MODIFIES POTENTIAL FOR SELECTION BY A STERILIZING PATHOGEN  

Microsoft Academic Search

Parasite-mediated selection is potentially of great importance in modulating genetic diversity. Genetic variation for resistance, the fuel for natural selection, appears to be common in host-parasite interactions, but responses to selection are rarely observed. In the present study, we tested whether environmental variation could mediate infection and determine evolutionary outcomes. Temperature was shown to dramatically alter the potential for parasite-mediated

Suzanne E. Mitchell; Emily S. Rogers; Tom J. Little; Andrew F. Read

2005-01-01

322

Genome analysis of Cronobacter phage vB_CsaP_Ss1 reveals an endolysin with potential for biocontrol of Gram-negative bacterial pathogens.  

PubMed

Bacteriophages and their derivatives are continuously gaining impetus as viable alternative therapeutic agents to control harmful multi-drug resistant bacterial pathogens, particularly in the food industry. The reduced efficacy of conventional antibiotics has resulted in a quest to find novel alternatives in the war against infectious disease. This study describes the full genome sequence of Cronobacter phage Ss1, with subsequent cloning and expression of its endolysin, capable of hydrolysing Gram-negative peptidoglycan. Cronobacter phage Ss1 is composed of 42,205 bp of double stranded DNA with a GC content of 46.1%. 57 ORFs were identified of which 18 could be assigned a putative function based on similarity to characterised proteins. The genome of Cronobacter phage Ss1 showed little similarity to the any other bacteriophage genomes available in the database and thus was considered unique. In addition, functional analysis on the predicted endolysin (LysSs1) was also investigated. Zymographic experiments demonstrated the hydrolytic activity of LysSs1 against Gram-negative peptidoglycan, thus highlighting the potential use of this enzyme as an antibacterial against Gram-negative pathogens. PMID:25371517

Endersen, Lorraine; Guinane, Caitriona; Johnston, Christopher; Neve, Horst; Coffey, Aidan; Ross, R Paul; McAuliffe, Olivia; O'Mahony, Jim

2014-11-01

323

Sex Hormone Regulation of Innate Immunity in the Female Reproductive Tract: The Role of Epithelial Cells in Balancing Reproductive Potential with Protection against Sexually Transmitted Pathogens  

PubMed Central

The immune system in the female reproductive tract (FRT) does not mount an attack against HIV or other sexually transmitted infections (STI) with a single endogenously produced microbicide or with a single arm of the immune system. Instead, the body deploys dozens of innate antimicrobials to the secretions of the female reproductive tract. Working together, these antimicrobials along with mucosal antibodies attack many different viral, bacterial and fungal targets. Within the FRT, the unique challenges of protection against sexually transmitted pathogens coupled with the need to sustain the development of an allogeneic fetus have evolved in such a way that sex hormones precisely regulate immune function to accomplish both tasks. The studies presented in this review demonstrate that estradiol and progesterone secreted during the menstrual cycle act both directly and indirectly on epithelial cells and other immune cells in the reproductive tract to modify immune function in a way that is unique to specific sites throughout the FRT. As presented in this review, studies from our laboratory and others demonstrate that the innate immune response is under hormonal control, varies with the stage of the menstrual cycle, and as such is suppressed at mid-cycle to optimize conditions for successful fertilization and pregnancy. In doing so, a window of STI vulnerability is created during which potential pathogens including HIV enter the reproductive tract to infect host targets. PMID:20367623

Wira, Charles R.; Fahey, John V.; Ghosh, Mimi; Patel, Mickey V.; Hickey, Danica K.; Ochiel, Daniel O.

2013-01-01

324

Effect of Ethanol on Differential Protein Production and Expression of Potential Virulence Functions in the Opportunistic Pathogen Acinetobacter baumannii  

PubMed Central

Acinetobacter baumannii persists in the medical environment and causes severe human nosocomial infections. Previous studies showed that low-level ethanol exposure increases the virulence of A. baumannii ATCC 17978. To better understand the mechanisms involved in this response, 2-D gel electrophoresis combined with mass spectrometry was used to investigate differential protein production in bacteria cultured in the presence or absence of ethanol. This approach showed that the presence of ethanol significantly induces and represses the production of 22 and 12 proteins, respectively. Although over 25% of the ethanol-induced proteins were stress-response related, the overall bacterial viability was uncompromised when cultured under these conditions. Production of proteins involved in lipid and carbohydrate anabolism was increased in the presence of ethanol, a response that correlates with increased carbohydrate biofilm content, enhanced biofilm formation on abiotic surfaces and decrease bacterial motility on semi-solid surfaces. The presence of ethanol also induced the acidification of bacterial cultures and the production of indole-3-acetic acid (IAA), a ubiquitous plant hormone that signals bacterial stress-tolerance and promotes plant-bacteria interactions. These responses could be responsible for the significantly enhanced virulence of A. baumannii ATCC 17978 cells cultured in the presence of ethanol when tested with the Galleria mellonella experimental infection model. Taken together, these observations provide new insights into the effect of ethanol in bacterial virulence. This alcohol predisposes the human host to infections by A. baumannii and could favor the survival and adaptation of this pathogen to medical settings and adverse host environments. PMID:23284824

Nwugo, Chika C.; Arivett, Brock A.; Zimbler, Daniel L.; Gaddy, Jennifer A.; Richards, Ashley M.; Actis, Luis A.

2012-01-01

325

Induction of indoleamine 2,3-dioxygenase by Borrelia burgdorferi in human immune cells correlates with pathogenic potential.  

PubMed

Borrelia burgdorferi, the bacterial agent of Lyme disease, induces the production of type I IFNs by human DCs through TLR7 and TLR9 signaling. This type I IFN response occurs in a genotype-dependent manner, with significantly higher levels of IFN-? elicited by B. burgdorferi strains that have a greater capacity for causing disseminated infection. A B. burgdorferi strain that was previously shown to induce IFN-? was found to elicit significantly higher levels of IDO1 protein and its downstream metabolite, kynurenine, compared with a B. burgdorferi mutant that lacks a single linear plasmid (lp36); this mutant is unable to induce IFN-? and is severely attenuated for infectivity in mice. Production of IDO by mDC and pDC populations, present within human PBMCs, was concomitant with increased expression of the DC maturation markers, CD83 and CCR7. The defects in IDO production and expression of CD83 and CCR7 could be restored by complementation of the mutant with lp36. Maximal IDO production in response to the wild-type strain was dependent on contributions by both type I IFN and IFN-?, the type II IFN. Induction of IDO was mediated by the same TLR7-dependent recognition of B. burgdorferi RNA that contributes to the production of type I IFNs by human DCs. The ability of IFN-?-inducing B. burgdorferi strains to stimulate production of IDO and kynurenines may be a mechanism that is used by the pathogen to promote localized immunosuppression and facilitate hematogenous dissemination. PMID:25420916

Love, Andrea C; Schwartz, Ira; Petzke, Mary M

2015-02-01

326

Respiratory Burst: Role in Signal Transduction in Alveolar Macrophages  

Microsoft Academic Search

Alveolar macrophages play an important role in defense against airborne pathogens and particles. These macrophages respond through both the adaptive and acquired immune responses, and through the activation of a multitude of signaling pathways. One major macrophage defense mechanism is respiratory burst, the production of reactive oxygen species (ROS). While the ROS produced may act directly in pathogen killing, they

Maureen R. Gwinn; Val Vallyathan

2006-01-01

327

Respiratory syncytial virus infections in infants affected by primary immunodeficiency.  

PubMed

Primary immunodeficiencies are rare inherited disorders that may lead to frequent and often severe acute respiratory infections. Respiratory syncytial virus (RSV) is one of the most frequent pathogens during early infancy and the infection is more severe in immunocompromised infants than in healthy infants, as a result of impaired T- and B-cell immune response unable to efficaciously neutralize viral replication, with subsequent increased viral shedding and potentially lethal lower respiratory tract infection. Several authors have reported a severe clinical course after RSV infections in infants and children with primary and acquired immunodeficiencies. Environmental prophylaxis is essential in order to reduce the infection during the epidemic season in hospitalized immunocompromised infants. Prophylaxis with palivizumab, a humanized monoclonal antibody against the RSV F protein, is currently recommended in high-risk infants born prematurely, with chronic lung disease or congenital heart disease. Currently however the prophylaxis is not routinely recommended in infants with primary immunodeficiency, although some authors propose the extension of prophylaxis to this high risk population. PMID:25089282

Lanari, Marcello; Vandini, Silvia; Capretti, Maria Grazia; Lazzarotto, Tiziana; Faldella, Giacomo

2014-01-01

328

Respiratory Syncytial Virus Infections in Infants Affected by Primary Immunodeficiency  

PubMed Central

Primary immunodeficiencies are rare inherited disorders that may lead to frequent and often severe acute respiratory infections. Respiratory syncytial virus (RSV) is one of the most frequent pathogens during early infancy and the infection is more severe in immunocompromised infants than in healthy infants, as a result of impaired T- and B-cell immune response unable to efficaciously neutralize viral replication, with subsequent increased viral shedding and potentially lethal lower respiratory tract infection. Several authors have reported a severe clinical course after RSV infections in infants and children with primary and acquired immunodeficiencies. Environmental prophylaxis is essential in order to reduce the infection during the epidemic season in hospitalized immunocompromised infants. Prophylaxis with palivizumab, a humanized monoclonal antibody against the RSV F protein, is currently recommended in high-risk infants born prematurely, with chronic lung disease or congenital heart disease. Currently however the prophylaxis is not routinely recommended in infants with primary immunodeficiency, although some authors propose the extension of prophylaxis to this high risk population. PMID:25089282

Capretti, Maria Grazia; Lazzarotto, Tiziana; Faldella, Giacomo

2014-01-01

329

Potential spread of highly pathogenic avian influenza H5N1 by wildfowl: dispersal ranges and rates determined from large-scale satellite telemetry  

USGS Publications Warehouse

1. Migratory birds are major candidates for long-distance dispersal of zoonotic pathogens. In recent years, wildfowl have been suspected of contributing to the rapid geographic spread of the highly pathogenic avian influenza (HPAI) H5N1 virus. Experimental infection studies reveal that some wild ducks, geese and swans shed this virus asymptomatically and hence have the potential to spread it as they move. 2. We evaluate the dispersive potential of HPAI H5N1 viruses by wildfowl through an analysis of the movement range and movement rate of birds monitored by satellite telemetry in relation to the apparent asymptomatic infection duration (AID) measured in experimental studies. We analysed the first large-scale data set of wildfowl movements, including 228 birds from 19 species monitored by satellite telemetry in 2006–2009, over HPAI H5N1 affected regions of Asia, Europe and Africa. 3. Our results indicate that individual migratory wildfowl have the potential to disperse HPAI H5N1 over extensive distances, being able to perform movements of up to 2900 km within timeframes compatible with the duration of asymptomatic infection. 4. However, the likelihood of such virus dispersal over long distances by individual wildfowl is low: we estimate that for an individual migratory bird there are, on average, only 5–15 days per year when infection could result in the dispersal of HPAI H5N1 virus over 500 km. 5. Staging at stopover sites during migration is typically longer than the period of infection and viral shedding, preventing birds from dispersing a virus over several consecutive but interrupted long-distance movements. Intercontinental virus dispersion would therefore probably require relay transmission between a series of successively infected migratory birds. 6. Synthesis and applications. Our results provide a detailed quantitative assessment of the dispersive potential of HPAI H5N1 virus by selected migratory birds. Such dispersive potential rests on the assumption that free-living wildfowl will respond analogously to captive, experimentally-infected birds, and that asymptomatic infection will not alter their movement abilities. Our approach of combining experimental exposure data and telemetry information provides an analytical framework for quantifying the risk of spread of avian-borne diseases.

Gaidet, Nicolas; Cappelle, Julien; Takekawa, John Y.; Prosser, Diann J.; Iverson, Samuel A.; Douglas, David C.; Perry, William M.; Mundkur, Taej; Newman, Scott H.

2010-01-01

330

Birth and pathogenesis of rogue respiratory viruses.  

PubMed

Emerging infectious diseases of zoonotic origin are shaping today's infectious disease field more than ever. In this article, we introduce and review three emerging zoonotic viruses. Novel hantaviruses emerged in the Americas in the mid-1990s as the cause of severe respiratory infections, designated hantavirus pulmonary syndrome, with case fatality rates of around 40%. Nipah virus emerged a few years later, causing respiratory infections and encephalitis in Southeast Asia, with case fatality rates ranging from 40% to more than 90%. A new coronavirus emerged in 2012 on the Arabian Peninsula with a clinical syndrome of acute respiratory infections, later designated as Middle East respiratory syndrome (MERS), and an initial case fatality rate of more than 40%. Our current state of knowledge on the pathogenicity of these three severe, emerging viral infections is discussed. PMID:25423349

Safronetz, David; Feldmann, Heinz; de Wit, Emmie

2015-01-24

331

Non-typeable Haemophilus influenzae, an under-recognised pathogen.  

PubMed

Non-typeable Haemophilus influenzae (NTHi) is a major cause of mucosal infections such as otitis media, sinusitis, conjunctivitis, and exacerbations of chronic obstructive pulmonary disease. In some regions, a strong causal relation links this pathogen with infections of the lower respiratory tract. In the past 20 years, a steady but constant increase has occurred in invasive NTHi worldwide, with perinatal infants, young children, and elderly people most at risk. Individuals with underlying comorbidities are most susceptible and infection is associated with high mortality. ?-lactamase production is the predominant mechanism of resistance. However, the emergence and spread of ?-lactamase-negative ampicillin-resistant strains in many regions of the world is of substantial concern, potentially necessitating changes to antibiotic treatment guidelines for community-acquired infections of the upper and lower respiratory tract and potentially increasing morbidity associated with invasive NTHi infections. Standardised surveillance protocols and typing methodologies to monitor this emerging pathogen should be implemented. International scientific organisations need to raise the profile of NTHi and to document the pathobiology of this microbe. PMID:25012226

Van Eldere, Johan; Slack, Mary P E; Ladhani, Shamez; Cripps, Allan W

2014-12-01

332

[Two cases of Corynebacterium pseudodiphtheriticum respiratory tract infection].  

PubMed

Corynebacterium pseudodiphtheriticum, one cause of respiratory tract infection, is rarely considered as a pathogen because it is among normal bacterial flora colonizing the oral cavity. We report two cases of C. pseudodiphtheriticum causing respiratory tract infection--an exacerbation of chronic obstructive pulmonary disease and pneumonia--, both in the presence of underlying respiratory disease. Both required antibiotics after first-line chemotherapy failed. Isolates were susceptible to beta-lactams. Gram-staining of respiratory tract specimens is important in diagnosing this infection and determining appropriate antimicrobial use. PMID:20170017

Morinaga, Yoshitomo; Yanagihara, Katsunori; Yamada, Koichi; Nakamura, Shigeki; Izumikawa, Koichi; Seki, Masafumi; Kakeya, Hiroshi; Yamamoto, Yoshihiro; Inoue, Yuichi; Kamihira, Shimeru; Kohno, Shigeru

2010-01-01

333

Food Scarcity, Neuroadaptations, and the Pathogenic Potential of Dieting in an Unnatural Ecology: Binge Eating and Drug Abuse  

PubMed Central

In the laboratory, food restriction has been shown to induce neuroadaptations in brain reward circuitry which are likely to be among those that facilitate survival during periods of food scarcity in the wild. However, the upregulation of mechanisms that promote foraging and reward-related learning may pose a hazard when food restriction is self-imposed in an ecology of abundant appetitive rewards. For example, episodes of loss of control during weight-loss dieting, use of drugs with addictive potential as diet aids, and alternating fasting with alcohol consumption in order to avoid weight gain, may induce synaptic plasticity that increases the risk of enduring maladaptive reward-directed behavior. In the present mini-review, representative basic research findings are outlined which indicate that food restriction alters the function of mesoaccumbens dopamine neurons, potentiates cellular and behavioral responses to D-1 and D-2 dopamine receptor stimulation, and increases stimulus-induced synaptic insertion of AMPA receptors in nucleus accumbens. Possible mechanistic underpinnings of increased drug reward magnitude, drug-seeking, and binge intake of sucrose in food-restricted animal subjects are discussed and possible implications for human weight-loss dieting are considered. PMID:21530562

Carr, Kenneth D.

2011-01-01

334

Host-parasite and genotype-by-environment interactions: temperature modifies potential for selection by a sterilizing pathogen.  

PubMed

Parasite-mediated selection is potentially of great importance in modulating genetic diversity. Genetic variation for resistance, the fuel for natural selection, appears to be common in host-parasite interactions, but responses to selection are rarely observed. In the present study, we tested whether environmental variation could mediate infection and determine evolutionary outcomes. Temperature was shown to dramatically alter the potential for parasite-mediated selection in two independent laboratory infection experiments at four temperatures. The bacterial parasite, Pasteuria ramosa, was extremely virulent at 20 degrees C and 25 degrees C, sterilizing its host, Daphnia magna, so that females often never produced a single brood. However, at 10 degrees C and 15 degrees C, the host-parasite interaction was much more benign, as nearly all females produced broods before becoming sterile. This association between virulence and temperature alone could stabilize coexistence and lead to the maintenance of diversity, because it would weaken parasite-mediated selection during parts of the season. Additionally, highly significant genotype-by-environment interactions were found, with changes in clone rank order for infection rates at different temperatures. Our results clearly show that the outcome of parasite-mediated selection in this system is strongly context dependent. PMID:15792228

Mitchell, Suzanne E; Rogers, Emily S; Little, Tom J; Read, Andrew F

2005-01-01

335

Post-genomic analyses of fungal lignocellulosic biomass degradation reveal the unexpected potential of the plant pathogen Ustilago maydis  

PubMed Central

Background Filamentous fungi are potent biomass degraders due to their ability to thrive in ligno(hemi)cellulose-rich environments. During the last decade, fungal genome sequencing initiatives have yielded abundant information on the genes that are putatively involved in lignocellulose degradation. At present, additional experimental studies are essential to provide insights into the fungal secreted enzymatic pools involved in lignocellulose degradation. Results In this study, we performed a wide analysis of 20 filamentous fungi for which genomic data are available to investigate their biomass-hydrolysis potential. A comparison of fungal genomes and secretomes using enzyme activity profiling revealed discrepancies in carbohydrate active enzymes (CAZymes) sets dedicated to plant cell wall. Investigation of the contribution made by each secretome to the saccharification of wheat straw demonstrated that most of them individually supplemented the industrial Trichoderma reesei CL847 enzymatic cocktail. Unexpectedly, the most striking effect was obtained with the phytopathogen Ustilago maydis that improved the release of total sugars by 57% and of glucose by 22%. Proteomic analyses of the best-performing secretomes indicated a specific enzymatic mechanism of U. maydis that is likely to involve oxido-reductases and hemicellulases. Conclusion This study provides insight into the lignocellulose-degradation mechanisms by filamentous fungi and allows for the identification of a number of enzymes that are potentially useful to further improve the industrial lignocellulose bioconversion process. PMID:22300648

2012-01-01

336

Evidence for the Emergence of Non-O1 and Non-O139 Vibrio cholerae Strains with Pathogenic Potential by Exchange of O-Antigen Biosynthesis Regions  

PubMed Central

The novel epidemic strain Vibrio cholerae O139 Bengal originated from a seventh-pandemic O1 El Tor strain by antigenic shift resulting from homologous recombination-mediated exchange of O-antigen biosynthesis (wb*) clusters. Conservation of the genetic organization of wb* regions seen in other serogroups raised the possibility of the existence of pathogenic non-O1 and non-O139 V. cholerae strains that emerged by similar events. To test this hypothesis, 300 V. cholerae isolates of non-O1 and non-O139 serogroups were screened for the presence of virulence genes and an epidemic genetic background by DNA dot blotting, IS1004 fingerprinting, and restriction fragment length polymorphism (RFLP) analysis. We found four non-O1 strains (serogroups O27, O37, O53, and O65) with an O1 genetic backbone suggesting exchange of wb* clusters. DNA sequence analysis of the O37 wb* region revealed that a novel ?23.4-kb gene cluster had replaced all but the ?4.2-kb right junction of the 22-kb O1 wbe region. In sharp contrast to the backbones, the virulence regions of the four strains were quite heterogeneous; the O53 and O65 strains had the El Tor vibrio pathogenicity island (VPI) cluster, the O37 strain had the classical VPI cluster, and the O27 strain had a novel VPI cluster. Two of the four strains carried CTX?; the O27 strain possessed a CTX? with a recently reported immune specificity (rstR-4** allele) and a novel ctxB allele, and the O37 strain had an El Tor CTX? (rstRET allele) and novel ctxAB alleles. Although the O53 and O65 strains lacked the ctxAB genes, they carried a pre-CTX? (i.e., rstRcla). Identification of non-O1 and non-O139 serogroups with pathogenic potential in epidemic genetic backgrounds means that attention should be paid to possible future epidemics caused by these serogroups and to the need for new, rapid vaccine development strategies. PMID:11953381

Li, Manrong; Shimada, Toshio; Morris, J. Glenn; Sulakvelidze, Alexander; Sozhamannan, Shanmuga

2002-01-01

337

Regulation of macrophage and dendritic cell function by pathogens and through immunomodulation in the avian mucosa.  

PubMed

Macrophages (MPh) and dendritic cells (DC) are members of the mononuclear phagocyte system. In chickens, markers to distinguish MPh from DC are lacking, but whether MPh and DC can be distinguished in humans and mice is under debate, despite the availability of numerous markers. Mucosal MPh and DC are strategically located to ingest foreign antigens, suggesting they can rapidly respond to invading pathogens. This review addresses our current understanding of DC and MPh function, the receptors expressed by MPh and DC involved in pathogen recognition, and the responses of DC and MPh against respiratory and intestinal pathogens in the chicken. Furthermore, potential opportunities are described to modulate MPh and DC responses to enhance disease resistance, highlighting modulation through nutraceuticals and vaccination. PMID:23542704

de Geus, Eveline D; Vervelde, Lonneke

2013-11-01

338

Pathogenic Potential, Genetic Diversity, and Population Structure of Escherichia coli Strains Isolated from a Forest-Dominated Watershed (Comox Lake) in British Columbia, Canada.  

PubMed

Escherichia coli isolates (n = 658) obtained from drinking water intakes of Comox Lake (2011 to 2013) were screened for the following virulence genes (VGs): stx1 and stx2 (Shiga toxin-producing E. coli [STEC]), eae and the adherence factor (EAF) gene (enteropathogenic E. coli [EPEC]), heat-stable (ST) enterotoxin (variants STh and STp) and heat-labile enterotoxin (LT) genes (enterotoxigenic E. coli [ETEC]), and ipaH (enteroinvasive E. coli [EIEC]). The only genes detected were eae and stx2, which were carried by 37.69% (n = 248) of the isolates. Only eae was harbored by 26.74% (n = 176) of the isolates, representing potential atypical EPEC strains, while only stx2 was detected in 10.33% (n = 68) of the isolates, indicating potential STEC strains. Moreover, four isolates were positive for both the stx2 and eae genes, representing potential EHEC strains. The prevalence of VGs (eae or stx2) was significantly (P < 0.0001) higher in the fall season, and multiple genes (eae plus stx2) were detected only in fall. Repetitive element palindromic PCR (rep-PCR) fingerprint analysis of 658 E. coli isolates identified 335 unique fingerprints, with an overall Shannon diversity (H') index of 3.653. Diversity varied among seasons over the years, with relatively higher diversity during fall. Multivariate analysis of variance (MANOVA) revealed that the majority of the fingerprints showed a tendency to cluster according to year, season, and month. Taken together, the results indicated that the diversity and population structure of E. coli fluctuate on a temporal scale, reflecting the presence of diverse host sources and their behavior over time in the watershed. Furthermore, the occurrence of potentially pathogenic E. coli strains in the drinking water intakes highlights the risk to human health associated with direct and indirect consumption of untreated surface water. PMID:25548059

Chandran, Abhirosh; Mazumder, Asit

2015-03-01

339

Differential sensitivity of osteoblasts and bacterial pathogens to 405-nm light highlighting potential for decontamination applications in orthopedic surgery  

NASA Astrophysics Data System (ADS)

Healthcare associated infections pose a major threat to patients admitted to hospitals and infection rates following orthopedic arthroplasty surgery are as high as 4%. A 405-nm high-intensity narrow spectrum light has been proven to reduce environmental contamination in hospital isolation rooms, and there is potential to develop this technology for application in arthroplasty surgery. Cultured rat osteoblasts were exposed to varying light intensities and it was found that exposures of up to a dose of 36 J/cm2 had no significant effect on cell viability [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay], function (alkaline phosphatase activity), and proliferation rate (BrdU cell proliferation assay). High irradiance exposures (54 J/cm2) significantly affected the cell viability indicating that the effects of 405-nm light on osteoblasts are dose dependent. Additionally, exposure of a variety of clinically related bacteria to a dose of 36 J/cm2 resulted in up to 100% kill. These results demonstrating the differential sensitivity of osteoblasts and bacteria to 405-nm light are an essential step toward developing the technique for decontamination in orthopedic surgery.

Ramakrishnan, Praveen; Maclean, Michelle; MacGregor, Scott J.; Anderson, John G.; Grant, M. Helen

2014-10-01

340

Detection of respiratory viruses by real-time polymerase chain reaction in outpatients with acute respiratory infection  

PubMed Central

Viruses are the major contributors to the morbidity and mortality of upper and lower acute respiratory infections (ARIs) for all age groups. The aim of this study was to determine the frequencies for a large range of respiratory viruses using a sensitive molecular detection technique in specimens from outpatients of all ages with ARIs. Nasopharyngeal aspirates were obtained from 162 individuals between August 2007-August 2009. Twenty-three pathogenic respiratory agents, 18 respiratory viruses and five bacteria were investigated using multiplex real-time reverse transcriptase polymerase chain reaction (RT-PCR) and indirect immunofluorescence assay (IIF). Through IIF, 33 (20.4%) specimens with respiratory virus were recognised, with influenza virus representing over half of the positive samples. Through a multiplex real-time RT-PCR assay, 88 (54.3%) positive samples were detected; the most prevalent respiratory viral pathogens were influenza, human rhinovirus and respiratory syncytial virus (RSV). Six cases of viral co-detection were observed, mainly involving RSV. The use of multiplex real-time RT-PCR increased the viral detection by 33.9% and revealed a larger number of respiratory viruses implicated in ARI cases, including the most recently described respiratory viruses [human bocavirus, human metapneumovirus, influenza A (H1N1) pdm09 virus, human coronavirus (HCoV) NL63 and HCoV HKU1]. PMID:25317699

Martins, Ronaldo Bragança; Carney, Sharon; Goldemberg, Daniel; Bonine, Lucas; Spano, Liliana Cruz; Siqueira, Marilda; Checon, Rita Elizabeth

2014-01-01

341

Pathogenic rare copy number variants in community-based schizophrenia suggest a potential role for clinical microarrays  

PubMed Central

Individually rare, large copy number variants (CNVs) contribute to genetic vulnerability for schizophrenia. Unresolved questions remain, however, regarding the anticipated yield of clinical microarray testing in schizophrenia. Using high-resolution genome-wide microarrays and rigorous methods, we investigated rare CNVs in a prospectively recruited community-based cohort of 459 unrelated adults with schizophrenia and estimated the minimum prevalence of clinically significant CNVs that would be detectable on a clinical microarray. A blinded review by two independent clinical cytogenetic laboratory directors of all large (>500 kb) rare CNVs in cases and well-matched controls showed that those deemed to be clinically significant were highly enriched in schizophrenia (16.4-fold increase, P < 0.0001). In a single community catchment area, the prevalence of individuals with these CNVs was 8.1%. Rare 1.7 Mb CNVs at 2q13 were found to be significantly associated with schizophrenia for the first time, compared with the prevalence in 23 838 population-based controls (42.9-fold increase, P = 0.0002). Additional novel findings that will facilitate the future clinical interpretation of smaller CNVs in schizophrenia include: (i) a greater proportion of individuals with two or more rare exonic CNVs >10 kb in size (1.5-fold increase, P = 0.0109) in schizophrenia; (ii) the systematic discovery of new candidate genes for schizophrenia; and, (iii) functional gene enrichment mapping highlighting a differential impact in schizophrenia of rare exonic deletions involving diverse functions, including neurodevelopmental and synaptic processes (4.7-fold increase, P = 0.0060). These findings suggest consideration of a potential role for clinical microarray testing in schizophrenia, as is now the suggested standard of care for related developmental disorders like autism. PMID:23813976

Costain, Gregory; Lionel, Anath C.; Merico, Daniele; Forsythe, Pamela; Russell, Kathryn; Lowther, Chelsea; Yuen, Tracy; Husted, Janice; Stavropoulos, Dimitri J.; Speevak, Marsha; Chow, Eva W.C.; Marshall, Christian R.; Scherer, Stephen W.; Bassett, Anne S.

2013-01-01

342

MTO1 mutations are associated with hypertrophic cardiomyopathy and lactic acidosis and cause respiratory chain deficiency in humans and yeast.  

PubMed

We report three families presenting with hypertrophic cardiomyopathy, lactic acidosis, and multiple defects of mitochondrial respiratory chain (MRC) activities. By direct sequencing of the candidate gene MTO1, encoding the mitochondrial-tRNA modifier 1, or whole exome sequencing analysis, we identified novel missense mutations. All MTO1 mutations were predicted to be deleterious on MTO1 function. Their pathogenic role was experimentally validated in a recombinant yeast model, by assessing oxidative growth, respiratory activity, mitochondrial protein synthesis, and complex IV activity. In one case, we also demonstrated that expression of wt MTO1 could rescue the respiratory defect in mutant fibroblasts. The severity of the yeast respiratory phenotypes partly correlated with the different clinical presentations observed in MTO1 mutant patients, although the clinical outcome was highly variable in patients with the same mutation and seemed also to depend on timely start of pharmacological treatment, centered on the control of lactic acidosis by dichloroacetate. Our results indicate that MTO1 mutations are commonly associated with a presentation of hypertrophic cardiomyopathy, lactic acidosis, and MRC deficiency, and that ad hoc recombinant yeast models represent a useful system to test the pathogenic potential of uncommon variants, and provide insight into their effects on the expression of a biochemical phenotype. PMID:23929671

Baruffini, Enrico; Dallabona, Cristina; Invernizzi, Federica; Yarham, John W; Melchionda, Laura; Blakely, Emma L; Lamantea, Eleonora; Donnini, Claudia; Santra, Saikat; Vijayaraghavan, Suresh; Roper, Helen P; Burlina, Alberto; Kopajtich, Robert; Walther, Anett; Strom, Tim M; Haack, Tobias B; Prokisch, Holger; Taylor, Robert W; Ferrero, Ileana; Zeviani, Massimo; Ghezzi, Daniele

2013-11-01

343

MTO1 Mutations are Associated with Hypertrophic Cardiomyopathy and Lactic Acidosis and Cause Respiratory Chain Deficiency in Humans and Yeast  

PubMed Central

We report three families presenting with hypertrophic cardiomyopathy, lactic acidosis, and multiple defects of mitochondrial respiratory chain (MRC) activities. By direct sequencing of the candidate gene MTO1, encoding the mitochondrial-tRNA modifier 1, or whole exome sequencing analysis, we identified novel missense mutations. All MTO1 mutations were predicted to be deleterious on MTO1 function. Their pathogenic role was experimentally validated in a recombinant yeast model, by assessing oxidative growth, respiratory activity, mitochondrial protein synthesis, and complex IV activity. In one case, we also demonstrated that expression of wt MTO1 could rescue the respiratory defect in mutant fibroblasts. The severity of the yeast respiratory phenotypes partly correlated with the different clinical presentations observed in MTO1 mutant patients, although the clinical outcome was highly variable in patients with the same mutation and seemed also to depend on timely start of pharmacological treatment, centered on the control of lactic acidosis by dichloroacetate. Our results indicate that MTO1 mutations are commonly associated with a presentation of hypertrophic cardiomyopathy, lactic acidosis, and MRC deficiency, and that ad hoc recombinant yeast models represent a useful system to test the pathogenic potential of uncommon variants, and provide insight into their effects on the expression of a biochemical phenotype. PMID:23929671

Baruffini, Enrico; Dallabona, Cristina; Invernizzi, Federica; Yarham, John W; Melchionda, Laura; Blakely, Emma L; Lamantea, Eleonora; Donnini, Claudia; Santra, Saikat; Vijayaraghavan, Suresh; Roper, Helen P; Burlina, Alberto; Kopajtich, Robert; Walther, Anett; Strom, Tim M; Haack, Tobias B; Prokisch, Holger; Taylor, Robert W; Ferrero, Ileana; Zeviani, Massimo; Ghezzi, Daniele

2013-01-01

344

Student Handbook Respiratory Therapy Program  

E-print Network

Student Handbook Respiratory Therapy Program Department of Cardiopulmonary Science School of Allied .......................................................................................................... 2 Respiratory Therapy Program Accreditation .................................................................. 2 Respiratory Therapy Program Goal and Objectives

345

Student Handbook Respiratory Therapy Program  

E-print Network

Student Handbook Respiratory Therapy Program Department of Cardiopulmonary Science School of Allied ............................................................................. 2 Respiratory Therapy Program Accreditation ............................................... 3 Respiratory Therapy Program Goal and Objectives ..................................... 3 Description

346

Pathogen intelligence  

PubMed Central

Different species inhabit different sensory worlds and thus have evolved diverse means of processing information, learning and memory. In the escalated arms race with host defense, each pathogenic bacterium not only has evolved its individual cellular sensing and behavior, but also collective sensing, interbacterial communication, distributed information processing, joint decision making, dissociative behavior, and the phenotypic and genotypic heterogeneity necessary for epidemiologic success. Moreover, pathogenic populations take advantage of dormancy strategies and rapid evolutionary speed, which allow them to save co-generated intelligent traits in a collective genomic memory. This review discusses how these mechanisms add further levels of complexity to bacterial pathogenicity and transmission, and how mining for these mechanisms could help to develop new anti-infective strategies. PMID:24551600

Steinert, Michael

2014-01-01

347

Computerized management of respiratory care.  

PubMed

Respiratory care as an organized discipline is only about 45 years old, and the management of this dynamic allied health profession has usually been characterized by a demand-for-service mentality. As pressure continues to control costs, those departments that maximize quality patient care cost-effectively with thoroughly documented outcomes are in a better position to compete for future resources. The practice of respiratory care is changing as is the practice of medical care in general. Accountability for resource consumption and the quality of the product delivered are essential elements in the delivery of respiratory modalities. We have developed and implemented a comprehensive patient-data-based approach to the management of respiratory care. The essential elements of this approach are (1) relative-value-unit procedure base; (2) individual, shift, and department productivity that is attached to the annual performance review process; (3) management reporting on a 24-hour basis, with biweekly review at the management level; (4) development and implementation of a comprehensive patient-data-documentation system that permits automatic patient billing and 100% data review for quality-assurance documentation; (5) the development of a medical alerting system that alerts the Medical Director and Respiratory Care staff to potentially harmful events that, if untreated, may result in increased morbidity or mortality; and (6) the development of concurrent and retrospective tools for patient-outcomes research. These functions are supported by an active Medical Informatics Department that is nationally recognized in medical computing and logic application. PMID:10145759

Greenway, L; Jeffs, M; Turner, K

1993-01-01

348

Characterization of antibiotic-resistant and potentially pathogenic Escherichia coli from soil fertilized with litter of broiler chickens fed antimicrobial-supplemented diets.  

PubMed

The objective of this study was to characterize antimicrobial resistance and virulence determinants of Escherichia coli from soil amended with litter from 36-day-old broiler chickens ( Gallus gallus domesticus ) fed with diets supplemented with a variety of antimicrobial agents. Soil samples were collected from plots before and periodically after litter application in August to measure E. coli numbers. A total of 295 E. coli were isolated from fertilized soil samples between August and March. Antibiotic susceptibility was determined by Sensititre, and polymerase chain reaction was performed to detect the presence of resistance and virulence genes. The results confirmed that E. coli survived and could be quantified by direct plate count for at least 7 months in soil following litter application in August. The effects of feed supplementation were observed on E. coli numbers in November and January. Among the 295 E. coli, the highest antibiotic resistance level was observed against tetracycline and ?-lactams associated mainly with the resistance genes tetB and bla(CMY-2), respectively. Significant treatment effects were observed for phylogenetic groups, antibiotic resistance profiles, and virulence gene frequencies. Serotyping, phylogenetic grouping, and pulsed-field gel electrophoresis confirmed that multiple-antibiotic-resistant and potentially pathogenic E. coli can survive in soil fertilized with litter for several months regardless of antimicrobials used in the feed. PMID:22906311

Merchant, Laura E; Rempel, Heidi; Forge, Tom; Kannangara, Tissa; Bittman, Shabtai; Delaquis, Pascal; Topp, Edward; Ziebell, Kim A; Diarra, Moussa S

2012-09-01

349

VibrioBase: A MALDI-TOF MS database for fast identification of Vibrio spp. that are potentially pathogenic in humans.  

PubMed

Mesophilic marine bacteria of the family Vibrionaceae, specifically V. cholerae, V. parahaemolyticus and V. vulnificus, are considered to cause severe illness in humans. Due to climate-change-driven temperature increases, higher Vibrio abundances and infections are predicted for Northern Europe, which in turn necessitates environmental surveillance programs to evaluate this risk. We propose that whole-cell matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) profiling is a promising tool for the fast and reliable species classification of environmental isolates. Because the reference database does not contain sufficient Vibrio spectra we generated the VibrioBase database in this study. Mass spectrometric data were generated from 997 largely environmental strains and filed in this new database. MALDI-TOF MS clusters were assigned based on the species classification obtained by analysis of partial rpoB (RNA polymerase beta-subunit) sequences. The affiliation of strains to species-specific clusters was consistent in 97% of all cases using both approaches, and the extended VibrioBase generated more specific species identifications with higher matching scores compared to the commercially available database. Therefore, we have made the VibrioBase database freely accessible, which paves the way for detailed risk assessment studies of potentially pathogenic Vibrio spp. from marine environments. PMID:25466918

Erler, René; Wichels, Antje; Heinemeyer, Ernst-August; Hauk, Gerhard; Hippelein, Martin; Reyes, Nadja Torres; Gerdts, Gunnar

2014-11-01

350

Denaturing gradient gel electrophoresis for nonlethal detection of Aeromonas salmonicida in salmonid mucus and its potential for other bacterial fish pathogens.  

PubMed

Denaturing gradient gel electrophoresis (DGGE) of 16S rDNA was used to nonlethally detect Aeromonas salmonicida and other bacteria in salmonid skin mucus. Mucus samples from wild spawning coho salmon (Oncorhynchus kisutch) with endemic A. salmonicida and from cultured lake trout (Salvelinus namaycush) were tested by PCR-DGGE and were compared with mucus culture on Coomassie brilliant blue agar and internal organ culture. PCR-DGGE gave a highly reproducible 4-band pattern for 9 strains of typical A. salmonicida, which was different from other Aeromonas spp. Aeromonas salmonicida presence in mucus was evident as a band that comigrated with the bottom band of the A. salmonicida 4-band pattern and was verified by sequencing. PCR-DGGE found 36 of 52 coho salmon positive for A. salmonicida, compared with 31 positive by mucus culture and 16 by organ culture. Numerous other bacteria were detected in salmonid mucus, including Pseudomonas spp., Shewanella putrefaciens, Aeromonas hydrophila and other aeromonads. However, Yersinia ruckeri was not detected in mucus from 27 lake trout, but 1 fish had a sorbitol-positive Y. ruckeri isolated from organ culture. Yersinia ruckeri seeded into a mucus sample suggested that PCR-DGGE detection of this bacterium from mucus was possible. PCR-DGGE allows nonlethal detection of A. salmonicida in mucus and differentiation of some Aeromonas spp. and has the potential to allow simultaneous detection of other pathogens present in fish mucus. PMID:22506865

Quinn, Robert A; Stevenson, Roselynn M W

2012-05-01

351

Bayesian Contact Tracing for Communicable Respiratory Disease  

PubMed Central

Objective The purpose of our work is to develop a system for automatic contact tracing with the goal of identifying individuals who are most likely infected, even if we do not have direct diagnostic information on their health status. Control of the spread of respiratory pathogens (e.g. novel influenza viruses) in the population using vaccination is a challenging problem that requires quick identification of the infectious agent followed by large-scale production and administration of a vaccine. This takes a significant amount of time. A complementary approach to control transmission is contact tracing and quarantining, which are currently applied to sexually transmitted diseases (STDs). For STDs, identifying the contacts that might have led to disease transmission is relatively easy; however, for respiratory pathogens, the contacts that can lead to transmission include a huge number of face-to-face daily social interactions that are impossible to trace manually. Introduction The evolution of novel influenza viruses in humans is a biological phenomenon that can not be stopped. All existing data suggest that vaccination against the morbidity and mortality of the novel influenza viruses is our best line of defence. Unfortunately, vaccination requires that the infectious agent to be quickly identified and a safe vaccine in large quantities is produced and administered. As was witnessed with the 2009 H1N1 influenza pandemic, these steps took a frustratingly long period during which the novel influenza virus continued its unstoppable and rapid global spreading. In addition to the different vaccination strategies (e.g. random mass vaccination, age structured vaccination), isolation and quarantining of infected individuals is another effective method used by the public health agencies to control the spreading of infectious diseases. Isolation is effective against any infectious disease, however it can be very hard to detect infectious individuals in the population when: Symptoms are ambiguous or easily misdiagnosed (e.g. 2009 H1N1 influenza outbreak shared many symptoms with many other influenza like illnesses)When the symptoms emerge after the individual become infectious. Methods We developed a dynamic Bayesian network model to process sensor information from users’ cellphones together with (possibly incomplete) diagnosis information to track the spread of disease in a population. Our model tracks real-time proximity contacts and can provide public health agencies with the probability of infection for each individual in the model. For testing our algorithm, we used a real-world mobile sensor dataset with 120 individuals collected over a period of 9 months, and we simulated an outbreak. Results We ran several experiments where different sub-populations were “infected” and “diagnosed.” By using the contact information, our model was able to automatically identify individuals in the population who were likely to be infected even though they were not directly “diagnosed” with an illness. Conclusions Automatic contact tracing for respiratory pathogens is a powerful idea, however we have identified several implementation challenges. The first challenge is scalability: we note that a contact tracing system with a hundred thousand individuals requires a Bayesian model with a billion nodes. Bayesian inference on models of this scale is an open problem and an active area of research. The second challenge is privacy protection: although the test data were collected in an academic setting, deploying any system will require appropriate safeguards for user privacy. Nonetheless, our work llustrates the potential for broader use of contact tracing for modeling and controlling disease transmission.

Shalaby, Ayman; Lizotte, Daniel

2013-01-01

352

Avian respiratory system disorders  

USGS Publications Warehouse

Diagnosing and treating respiratory diseases in avian species requires a basic knowledge about the anatomy and physiology of this system in birds. Differences between mammalian and avian respiratory system function, diagnosis, and treatment are highlighted.

Olsen, G.H.

1989-01-01

353

Upper respiratory tract (image)  

MedlinePLUS

The major passages and structures of the upper respiratory tract include the nose or nostrils, nasal cavity, mouth, throat (pharynx), and voice box (larynx). The respiratory system is lined with a mucous membrane that ...

354

MSFC Respiratory Protection Services  

NASA Technical Reports Server (NTRS)

An overview of the Marshall Space Flight Center Respiratory Protection program is provided in this poster display. Respiratory protection personnel, building, facilities, equipment, customers, maintenance and operational activities, and Dynatech fit testing details are described and illustrated.

CoVan, James P.

1999-01-01

355

Environmental Health and Safety RESPIRATORY  

E-print Network

Environmental Health and Safety RESPIRATORY PROTECTION PROGRAM Revised March 2014 #12;RESPIRATORY of Respiratory Protection Equipment................................................3 2.4 Medical Evaluation Considerations For Use Of Supplied Air Respirators ...............7 2.7.3 Respiratory Protection Equipment

Farritor, Shane

356

A Legacy of Low-Impact Logging does not Elevate Prevalence of Potentially Pathogenic Protozoa in Free-Ranging Gorillas and Chimpanzees in the Republic of Congo: Logging and Parasitism in African Apes  

PubMed Central

Many studies have examined the long-term effects of selective logging on the abundance and diversity of free-ranging primates. Logging is known to reduce the abundance of some primate species through associated hunting and the loss of food trees for frugivores; however, the potential role of pathogens in such primate population declines is largely unexplored. Selective logging results in a suite of alterations in host ecology and forest structure that may alter pathogen dynamics in resident wildlife populations. In addition, environmental pollution with human fecal material may present a risk for wildlife infections with zoonotic protozoa, such as Cryptosporidium and Giardia. To better understand this interplay, we compared patterns of infection with these potentially pathogenic protozoa in sympatric western lowland gorillas (Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes troglodytes) in the undisturbed Goualougo Triangle of Nouabalé-Ndoki National Park and the adjacent previously logged Kabo Concession in northern Republic of Congo. No Cryptosporidium infections were detected in any of the apes examined and prevalence of infection with Giardia was low (3.73% overall) and did not differ between logged and undisturbed forest for chimpanzees or gorillas. These results provide a baseline for prevalence of these protozoa in forest-dwelling African apes and suggest that low-intensity logging may not result in long-term elevated prevalence of potentially pathogenic protozoa. PMID:20238141

Morgan, David; Deutsch, J. Charlie; Kuhlenschmidt, Mark S.; Salzer, Johanna S.; Cameron, Kenneth; Reed, Trish; Sanz, Crickette

2010-01-01

357

Bioluminescent Diagnostic Imaging to Characterize Altered Respiratory Tract Colonization by the Burkholderia Pseudomallei Capsule Mutant  

PubMed Central

Pneumonia is a common manifestation of the potentially fatal disease melioidosis, caused by the select agent bacteria Burkholderia pseudomallei. In this study we describe a new model system to investigate pulmonary melioidosis in vivo using bioluminescent-engineered bacteria in a murine respiratory disease model. Studies were performed to validate that the stable, light producing B. pseudomallei strain JW280 constitutively produced light in biologically relevant host–pathogen interactions. Hairless outbred SKH1 mice were used to enhance the ability to monitor B. pseudomallei respiratory disease, and were found to be similarly susceptible to respiratory melioidosis as BALB/c mice. This represents the first demonstration of in vivo diagnostic imaging of pulmonary melioidosis permitting the detection of B. pseudomallei less than 24?h post-infection. Diagnostic imaging of pulmonary melioidosis revealed distinct temporal patterns of bacterial colonization unique to both BALB/c and SKH1 mice. Validation of these model systems included the use of the previously characterized capsule mutant, which was found to colonize the upper respiratory tract at significantly higher levels than the wild type strain. These model systems allow for high resolution detection of bacterial pulmonary disease which will facilitate studies of therapeutics and basic science evaluation of melioidosis. PMID:21720539

Warawa, Jonathan M.; Long, Dan; Rosenke, Rebecca; Gardner, Don; Gherardini, Frank C.

2011-01-01

358

Resolution of the cellular proteome of the nucleocapsid protein from a highly pathogenic isolate of porcine reproductive and respiratory syndrome virus identifies PARP-1 as a cellular target whose interaction is critical for virus biology.  

PubMed

Porcine reproductive and respiratory syndrome virus (PRRSV) is a major threat to the swine industry and food security worldwide. The nucleocapsid (N) protein is a major structural protein of PRRSV. The primary function of this protein is to encapsidate the viral RNA genome, and it is also thought to participate in the modulation of host cell biology and recruitment of cellular factors to facilitate virus infection. In order to the better understand these latter roles the cellular interactome of PRRSV N protein was defined using label free quantitative proteomics. This identified several cellular factors that could interact with the N protein including poly [ADP-ribose] polymerase 1 (PARP-1), a cellular protein, which can add adenosine diphosphate ribose to a protein. Use of the PARP-1 small molecule inhibitor, 3-AB, in PRRSV infected cells demonstrated that PARP-1 was required and acted as an enhancer factor for virus biology. Serial growth of PRRSV in different concentrations of 3-AB did not yield viruses that were able to grow with wild type kinetics, suggesting that by targeting a cellular protein crucial for virus biology, resistant phenotypes did not emerge. This study provides further evidence that cellular proteins, which are critical for virus biology, can also be targeted to ablate virus growth and provide a high barrier for the emergence of drug resistance. PMID:25614100

Liu, Long; Lear, Zoe; Hughes, David J; Wu, Weining; Zhou, En-Min; Whitehouse, Adrian; Chen, Hongying; Hiscox, Julian A

2015-03-23

359

A New High-Speed Droplet-Real-Time Polymerase Chain Reaction Method Can Detect Bovine Respiratory Syncytial Virus in Less than 10 Min  

PubMed Central

ABSTRACT The polymerase chain reaction (PCR) has been widely used for diagnosis of infectious diseases of domestic animals. Rapid detection of respiratory pathogens of cattle is useful for making therapeutic decisions. Therefore, we developed a new genetic-based method called droplet-real-time PCR, which can detect bovine respiratory syncytial virus (BRSV) within 10 min. Our droplet-real-time PCR markedly reduced the reaction time of reverse transcription-PCR while maintaining the same sensitivity as conventional real-time PCR, and it can be used as a rapid assay for detection of BRSV. Furthermore, our method is potentially applicable for rapid diagnosis of almost all infectious diseases, including highly pathogenic avian influenza virus. PMID:24285011

UEHARA, Masayuki; MATSUDA, Kazuyuki; SUGANO, Mitsutoshi; HONDA, Takayuki

2013-01-01

360

Satellite tracking on the flyways of brown-headed gulls and their potential role in the spread of highly pathogenic avian influenza H5N1 virus.  

PubMed

Brown-headed gulls (Larus brunnicephalus), winter visitors of Thailand, were tracked by satellite telemetry during 2008-2011 for investigating their roles in the highly pathogenic avian influenza (HPAI) H5N1 virus spread. Eight gulls negative for influenza virus infection were marked with solar-powered satellite platform transmitters at Bang Poo study site in Samut Prakarn province, Thailand; their movements were monitored by the Argos satellite tracking system, and locations were mapped. Five gulls completed their migratory cycles, which spanned 7 countries (China, Bangladesh, India, Myanmar, Thailand, Cambodia, and Vietnam) affected by the HPAI H5N1 virus. Gulls migrated from their breeding grounds in China to stay overwinter in Thailand and Cambodia; while Bangladesh, India, Myanmar, and Vietnam were the places of stopovers during migration. Gulls traveled an average distance of about 2400 km between Thailand and China and spent 1-2 weeks on migration. Although AI surveillance among gulls was conducted at the study site, no AI virus was isolated and no H5N1 viral genome or specific antibody was detected in the 75 gulls tested, but 6.6% of blood samples were positive for pan-influenza A antibody. No AI outbreaks were reported in areas along flyways of gulls in Thailand during the study period. Distance and duration of migration, tolerability of the captive gulls to survive the HPAI H5N1 virus challenge and days at viral shedding after the virus challenging suggested that the Brown-headed gull could be a potential species for AI spread, especially among Southeast Asian countries, the epicenter of H5N1 AI outbreak. PMID:23209623

Ratanakorn, Parntep; Wiratsudakul, Anuwat; Wiriyarat, Witthawat; Eiamampai, Krairat; Farmer, Adrian H; Webster, Robert G; Chaichoune, Kridsada; Suwanpakdee, Sarin; Pothieng, Duangrat; Puthavathana, Pilaipan

2012-01-01

361

C-terminal truncation of the transmembrane protein of an attenuated lentiviral vaccine alters its in vitro but not in vivo replication and weakens its potential pathogenicity.  

PubMed

Preliminary studies revealed that the gene of the gp45 transmembrane protein (TM) of the attenuated equine infectious anemia virus (EIAV) vaccine strain EIAV(FDDV13) had a high frequency of a premature stop codon at position 261W, which generated a 154-residue truncation at the C-terminus. EIAV(FDDV-TM36), a recombinant virus with the TM truncated at the intracytoplasmic (CT) domain due to the presence of a stop codon, was constructed based on EIAV(FDDV)3-8, which is a proviral derivative of the vaccine. EIAV(FDDV-TM36) had a significantly reduced replication capability compared to EIAV(FDDV)3-8 in equine or donkey monocyte-derived macrophages and a decreased ability to induce apoptosis. However, both viruses raised a similar plasma viral load in inoculated horses and did not induce clinical symptoms of EIA. To further compare the in vivo behavior between EIAV(FDDV-TM36) and EIAV(FDDV)3-8, inoculated horses were transiently immunosuppressed with dexamethasone. While three of the four horses inoculated with EIAV(FDDV)3-8 demonstrated significant increases in viral loads after the drug treatment, none of the four horses inoculated with EIAV(FDDV-TM36) showed a statistically increased plasma viral load. Significantly increased neutralizing antibody levels were also observed in the group of horses inoculated with EIAV(FDDV)3-8, but not EIAV(FDDV-TM36), after immunosuppression. Our results indicate that although the CT truncation of TM decreased viral replication in cultivated equine and donkey macrophages, the primary target cell of EIAV, and did not influence the plasma viral load of inoculated hosts, it weakened the potential pathogenicity of the vaccine. The host immunity is presumably responsible for the equal in vivo replication levels of viruses with either the CT-truncated or prototype TM. PMID:21539871

Jiang, Cheng-Gang; Gao, Xu; Ma, Jian; Lin, Yue-Zhi; Wang, Xue-Feng; Zhao, Li-Ping; Hua, Yue-Ping; Liu, Di; Zhou, Jian-Hua

2011-06-01

362

Satellite Tracking on the Flyways of Brown-Headed Gulls and Their Potential Role in the Spread of Highly Pathogenic Avian Influenza H5N1 Virus  

PubMed Central

Brown-headed gulls (Larus brunnicephalus), winter visitors of Thailand, were tracked by satellite telemetry during 2008–2011 for investigating their roles in the highly pathogenic avian influenza (HPAI) H5N1 virus spread. Eight gulls negative for influenza virus infection were marked with solar-powered satellite platform transmitters at Bang Poo study site in Samut Prakarn province, Thailand; their movements were monitored by the Argos satellite tracking system, and locations were mapped. Five gulls completed their migratory cycles, which spanned 7 countries (China, Bangladesh, India, Myanmar, Thailand, Cambodia, and Vietnam) affected by the HPAI H5N1 virus. Gulls migrated from their breeding grounds in China to stay overwinter in Thailand and Cambodia; while Bangladesh, India, Myanmar, and Vietnam were the places of stopovers during migration. Gulls traveled an average distance of about 2400 km between Thailand and China and spent 1–2 weeks on migration. Although AI surveillance among gulls was conducted at the study site, no AI virus was isolated and no H5N1 viral genome or specific antibody was detected in the 75 gulls tested, but 6.6% of blood samples were positive for pan-influenza A antibody. No AI outbreaks were reported in areas along flyways of gulls in Thailand during the study period. Distance and duration of migration, tolerability of the captive gulls to survive the HPAI H5N1 virus challenge and days at viral shedding after the virus challenging suggested that the Brown-headed gull could be a potential species for AI spread, especially among Southeast Asian countries, the epicenter of H5N1 AI outbreak. PMID:23209623

Ratanakorn, Parntep; Wiratsudakul, Anuwat; Wiriyarat, Witthawat; Eiamampai, Krairat; Farmer, Adrian H.; Webster, Robert G.; Chaichoune, Kridsada; Suwanpakdee, Sarin; Pothieng, Duangrat; Puthavathana, Pilaipan

2012-01-01

363

Induction of endotoxin tolerance by pathogenic Neisseria is correlated with the inflammatory potential of lipooligosaccharides and regulated by microRNA-146a.  

PubMed

In this article, we report that retreatment of human monocytic THP-1 cells and primary monocytes with pathogenic Neisseria or with purified lipooligosaccharides (LOS) after previous exposure to LOS induced immune tolerance, as evidenced by reduced TNF-? and IL-1? cytokine expression. LOS that we have previously shown to vary in their potential to activate TLR4 signaling, which was correlated with differences in levels of lipid A phosphorylation, had similarly variable ability to induce tolerance. Efficacy for induction of tolerance was proportional to the level of lipid A phosphorylation, as LOS from meningococcal strain 89I with the highest degree of phosphorylation was the most tolerogenic following retreatment with LOS or whole bacteria, compared with LOS from gonococcal strains 1291 and GC56 with reduced levels of phosphorylation. Hydrogen fluoride treatment of 89I LOS to remove phosphates rendered the LOS nontolerogenic. Tolerance induced by the more highly inflammatory meningococcal LOS was correlated with significantly greater downregulation of p38 activation, greater induction of the expression of A20 and of microRNA-146a, and greater reductions in IL-1R-associated kinase 1 and TRAF6 levels following LOS retreatment of cells. The role of miR-146a in regulation of induction of TNF-? was confirmed by transfecting cells with an inhibitor and a mimic of miR-146a. Our results provide a mechanistic framework for understanding the variable pathophysiology of meningococcal and gonococcal infections given that after an initial exposure, greater upregulation of microRNA-146a by more highly inflammatory LOS conversely leads to the suppression of immune responses, which would be expected to facilitate bacterial survival and dissemination. PMID:24442429

Liu, Mingfeng; John, Constance M; Jarvis, Gary A

2014-02-15

364

Targeting phosphoinositide 3-kinase ? for the treatment of respiratory diseases.  

PubMed

Asthma and chronic obstructive pulmonary disease (COPD) are characterized in their pathogenesis by chronic inflammation in the airways. Phosphoinositide 3-kinase ? (PI3K?), a lipid kinase expressed predominantly in leukocytes, is thought to hold much promise as a therapeutic target for such inflammatory conditions. Of particular interest for the treatment of severe respiratory disease is the observation that inhibition of PI3K? may restore steroid effectiveness under conditions of oxidative stress. PI3K? inhibition may also prevent recruitment of inflammatory cells, including T lymphocytes and neutrophils, as well as the release of proinflammatory mediators, such as cytokines, chemokines, reactive oxygen species, and proteolytic enzymes. In addition, targeting the PI3K? pathway could reduce the incidence of pathogen-induced exacerbations by improving macrophage-mediated bacterial clearance. In this review, we discuss the potential and highlight the unknowns of targeting PI3K? for the treatment of respiratory disease, focusing on recent developments in the role of the PI3K? pathway in inflammatory cell types believed to be critical to the pathogenesis of COPD. PMID:23551101

Sriskantharajah, Srividya; Hamblin, Nicole; Worsley, Sally; Calver, Andrew R; Hessel, Edith M; Amour, Augustin

2013-03-01

365

New use of broomcorn millets for production of granular cultures of aphid-pathogenic fungus Pandora neoaphidis for high sporulation potential and infectivity to Myzus persicae.  

PubMed

Glutinous broomcorn millets from the crop Panicum miliaceum were first used as substrate to produce granular cultures of Pandora neoaphidis, an obligate fungal pathogen specific to aphids. Carrying a water content of 36.5% after being steamed in a regular autoclaving procedure, millet grains of each 15 g (dry weight) in a 100-ml flask were mixed with 3 ml modified Sabouraud dextrose broth containing half a mashed colony of P. neoaphidis grown on egg yolk milk agar and then incubated at 20 degrees C and a light/dark cycle of 12 h/12 h for 21 days. Based on individually monitoring conidial production potential of 20 millet grains sampled from an arbitrarily taken flask at 3-day intervals, the millet cultures incubated for 6-15 days were capable of producing 16.8-23.4 x 10(4) conidia per millet grain with conidial ejection lasting for up to 6 days. The cultured millet grains individually produced significantly more conidia than apterous adults of Myzus persicae killed by P. neoaphidis (8.4 x 10(4) conidia per cadaver) and sporulated twice longer. The modeling of time-dose-mortality data from bioassays on M. persicae apterae exposed to conidial showers from the cultured millet grains and the mycelial mats produced in liquid culture resulted in similar estimates of LC(50) (millets: 21.4, 7.3, and 4.9 conidia mm(-2) on days 5-7 after exposure; mycelial mats: 22.1, 10.6, and 7.7 conidia mm(-2)) although the LT(50) estimated at a given conidial concentration was slightly smaller for the millet cultures than for the mycelial mats. This indicates that the millet grains cultured with P. neoaphidis produced conidia as infective as or slightly more infective to M. persicae than those from the mycelial mats. Based on the sporulation potential, infectivity, and ease and cost of the millet cultures, the method developed in this study highly improved in vitro cultures of P. neoaphidis and may adapt to culturing other entomophthoralean fungi for microbial control of insect pests. PMID:14592724

Hua, Li; Feng, Ming-Guang

2003-10-24

366

Immunodetection of fungal and oomycete pathogens: Established and emerging threats to human health, animal welfare and global food security.  

PubMed

Abstract Filamentous fungi (moulds), yeast-like fungi, and oomycetes cause life-threatening infections of humans and animals and are a major constraint to global food security, constituting a significant economic burden to both agriculture and medicine. As well as causing localized or systemic infections, certain species are potent producers of allergens and toxins that exacerbate respiratory diseases or cause cancer and organ damage. We review the pathogenic and toxigenic organisms that are etiologic agents of both animal and plant diseases or that have recently emerged as serious pathogens of immunocompromised individuals. The use of hybridoma and phage display technologies and their success in generating monoclonal antibodies for the detection and control of fungal and oomycete pathogens are explored. Monoclonal antibodies hold enormous potential for the development of rapid and specific tests for the diagnosis of human mycoses, however, unlike plant pathology, their use in medical mycology remains to be fully exploited. PMID:23734714

Thornton, Christopher R; Wills, Odette E

2015-02-01

367

Respiratory viruses in children hospitalized for acute lower respiratory tract infection in Ghana  

PubMed Central

Background Acute respiratory tract infections are one of the major causes of morbidity and mortality among young children in developing countries. Information on the viral aetiology of acute respiratory infections in developing countries is very limited. The study was done to identify viruses associated with acute lower respiratory tract infection among children less than 5 years. Method Nasopharyngeal samples and blood cultures were collected from children less than 5 years who have been hospitalized for acute lower respiratory tract infection. Viruses and bacteria were identified using Reverse Transcriptase Real-Time Polymerase Chain Reaction and conventional biochemical techniques. Results Out of 128 patients recruited, 33(25.88%%, 95%CI: 18.5% to 34.2%) were positive for one or more viruses. Respiratory Syncytial Virus (RSV) was detected in 18(14.1%, 95%CI: 8.5% to 21.3%) patients followed by Adenoviruses (AdV) in 13(10.2%, 95%CI: 5.5% to 16.7%), Parainfluenza (PIV type: 1, 2, 3) in 4(3.1%, 95%CI: 0.9% to 7.8%) and influenza B viruses in 1(0.8%, 95%CI: 0.0 to 4.3). Concomitant viral and bacterial co-infection occurred in two patients. There were no detectable significant differences in the clinical signs, symptoms and severity for the various pathogens isolated. A total of 61.1% (22/36) of positive viruses were detected during the rainy season and Respiratory Syncytial Virus was the most predominant. Conclusion The study has demonstrated an important burden of respiratory viruses as major causes of childhood acute respiratory infection in a tertiary health institution in Ghana. The data addresses a need for more studies on viral associated respiratory tract infection. PMID:22490115

2012-01-01

368

Comprehensive non-clinical respiratory evaluation of promising new drugs  

SciTech Connect

The need to evaluate the potential for new drugs to produce adverse effects on respiratory function in non-clinical safety assessment is based on the known effects of drugs from a variety of pharmacological/therapeutic classes on the respiratory system, the life-threatening consequences of respiratory dysfunction, and compliance with world-wide regulatory safety guidelines. The objective of this article is to provide a brief overview of the functional disorders of the respiratory system and to present the strategy and techniques considered to be most appropriate for detecting and characterizing drug-induced respiratory disorders in non-clinical safety studies.

Murphy, Dennis J. [Department of Safety Pharmacology, GlaxoSmithKline Pharmaceuticals, 709 Swedeland Road, King of Prussia, PA 19406 (United States)]. E-mail: dennis.j.murphy@GSK.com

2005-09-01

369

A Legacy of Low-Impact Logging does not Elevate Prevalence of Potentially Pathogenic Protozoa in Free-Ranging Gorillas and Chimpanzees in the Republic of Congo: Logging and Parasitism in African Apes  

Microsoft Academic Search

Many studies have examined the long-term effects of selective logging on the abundance and diversity of free-ranging primates.\\u000a Logging is known to reduce the abundance of some primate species through associated hunting and the loss of food trees for\\u000a frugivores; however, the potential role of pathogens in such primate population declines is largely unexplored. Selective\\u000a logging results in a suite

Thomas R. Gillespie; David Morgan; J. Charlie Deutsch; Mark S. Kuhlenschmidt; Johanna S. Salzer; Kenneth Cameron; Trish Reed; Crickette Sanz

2009-01-01

370

Vaccine-preventable adenoviral respiratory illness in US military recruits, 1999-2004  

PubMed Central

Background and Methods: The high burden of respiratory infections in military populations is well documented throughout history. The primary pathogen responsible for morbidity among US recruits in training was shown to be adenovirus. Highly efficacious oral vaccines were used for 25 years, but vaccine production ceased in 1996, and available stores were depleted by early 1999. Surveillance for acute febrile respiratory illness was performed at eight military recruit training sites throughout the United States from July 1999 through June 2004 to document rates after loss of the vaccines. Laboratory diagnoses complimented the surveillance efforts. Results: Over the 5 years, nearly 12 million person-weeks were followed and an estimated 110,172 febrile respiratory illness cases and 73,748 adenovirus cases were identified. Rates of illness were highest at the Navy and Air Force training centers, with average annual rates of 1.20 and 1.35 cases per 100 recruit- weeks respectively. Adenoviral-associated illness rates peaked in weeks 3 to 5 of training, depending upon service. Conclusions: The burden of adenoviral illness among US recruit populations has returned to high levels since loss of the vaccines. Restoration of an effective adenovirus vaccine effort within the military is anticipated by 2008, potentially reducing the adenovirus morbidity suffered in this vulnerable population. Efforts to determine the burden of adenovirus and potential benefits of vaccination in civilian populations are being renewed. PMID:16480793

Russell, Kevin L.; Hawksworth, Anthony W.; Ryan, Margaret A. K.; Strickler, Jennifer; Irvine, Marina; Hansen, Christian J.; Gray, Gregory C.; Gaydos, Joel C.

2007-01-01

371

Metagenomic analysis of a sample from a patient with respiratory tract infection reveals the presence of a ?-papillomavirus  

PubMed Central

Previously unknown or unexpected pathogens may be responsible for that proportion of respiratory diseases in which a causative agent cannot be identified. The application of broad-spectrum, sequence independent virus discovery techniques may be useful to reduce this proportion and widen our knowledge about respiratory pathogens. Thanks to the availability of high-throughput sequencing (HTS) technology, it became today possible to detect viruses which are present at a very low load, but the clinical relevance of those viruses must be investigated. In this study we used VIDISCA-454, a restriction enzyme based virus discovery method that utilizes Roche 454 HTS system, on a nasal swab collected from a subject with respiratory complaints. A ?-papillomavirus was detected (complete genome: 7142 bp) and its role in disease was investigated. Respiratory samples collected both during the acute phase of the illness and 2 weeks after full recovery contained the virus. The patient presented antibodies directed against the virus but there was no difference between IgG levels in blood samples collected during the acute phase and 2 weeks after full recovery. We therefore concluded that the detected ?-papillomavirus is unlikely to be the causative agent of the respiratory complaints and its presence in the nose of the patient is not related to the disease. Although HTS based virus discovery techniques proved their great potential as a tool to clarify the etiology of some infectious diseases, the obtained information must be subjected to cautious interpretations. This study underlines the crucial importance of performing careful investigations on viruses identified when applying sensitive virus discovery techniques, since the mere identification of a virus and its presence in a clinical sample are not satisfactory proofs to establish a causative link with a disease. PMID:25071755

Canuti, Marta; Deijs, Martin; Jazaeri Farsani, Seyed M.; Holwerda, Melle; Jebbink, Maarten F.; de Vries, Michel; van Vugt, Saskia; Brugman, Curt; Verheij, Theo; Lammens, Christine; Goossens, Herman; Loens, Katherine; Ieven, Margareta; van der Hoek, Lia

2014-01-01

372

Identification of Common Biological Pathways and Drug Targets Across Multiple Respiratory Viruses Based on Human Host Gene Expression Analysis  

PubMed Central

Background Pandemic and seasonal respiratory viruses are a major global health concern. Given the genetic diversity of respiratory viruses and the emergence of drug resistant strains, the targeted disruption of human host-virus interactions is a potential therapeutic strategy for treating multi-viral infections. The availability of large-scale genomic datasets focused on host-pathogen interactions can be used to discover novel drug targets as well as potential opportunities for drug repositioning. Methods/Results In this study, we performed a large-scale analysis of microarray datasets involving host response to infections by influenza A virus, respiratory syncytial virus, rhinovirus, SARS-coronavirus, metapneumonia virus, coxsackievirus and cytomegalovirus. Common genes and pathways were found through a rigorous, iterative analysis pipeline where relevant host mRNA expression datasets were identified, analyzed for quality and gene differential expression, then mapped to pathways for enrichment analysis. Possible repurposed drugs targets were found through database and literature searches. A total of 67 common biological pathways were identified among the seven different respiratory viruses analyzed, representing fifteen laboratories, nine different cell types, and seven different array platforms. A large overlap in the general immune response was observed among the top twenty of these 67 pathways, adding validation to our analysis strategy. Of the top five pathways, we found 53 differentially expressed genes affected by at least five of the seven viruses. We suggest five new therapeutic indications for existing small molecules or biological agents targeting proteins encoded by the genes F3, IL1B, TNF, CASP1 and MMP9. Pathway enrichment analysis also identified a potential novel host response, the Parkin-Ubiquitin Proteasomal System (Parkin-UPS) pathway, which is known to be involved in the progression of neurodegenerative Parkinson's disease. Conclusions Our study suggests that multiple and diverse respiratory viruses invoke several common host response pathways. Further analysis of these pathways suggests potential opportunities for therapeutic intervention. PMID:22432004

Smith, Steven B.; Dampier, William; Tozeren, Aydin; Brown, James R.; Magid-Slav, Michal

2012-01-01

373

A Molecular Epidemiology Survey of Respiratory Adenoviruses Circulating in Children Residing in Southern Palestine  

Microsoft Academic Search

A molecular epidemiology survey was performed in order to establish and document the respiratory adenovirus pathogen profiles among children in Southern Palestine. Three hundred and thirty-eight hospitalized pediatric cases with adenovirus-associated respiratory tract infections were analyzed. Forty four cases out of the 338 were evaluated in more detail for the adenoviruses types present. All of the children resided in Southern

Lina Qurei; Donald Seto; Zaidoun Salah; Maysa Azzeh

2012-01-01

374

Respiratory syncytial virus infection reduces lung inflammation and fibrosis in mice exposed to vanadium pentoxide  

Microsoft Academic Search

BACKGROUND: Vanadium pentoxide (V2O5) exposure is a cause of occupational bronchitis and airway fibrosis. Respiratory syncytial virus (RSV) is a ubiquitous pathogen that causes airway inflammation. It is unknown whether individuals with pre-existing respiratory viral infection are susceptible to V2O5-induced bronchitis. We hypothesized that respiratory viral infection will exacerbate vanadium-induced lung fibrosis. METHODS: In this study we investigated the effect

Elizabeth A Turpin; Aurita Antao-Menezes; Mark F Cesta; James B Mangum; Duncan G Wallace; Edilberto Bermudez; James C Bonner

2010-01-01

375

Detection of respiratory viruses and Bordetella bronchiseptica in dogs with acute respiratory tract infections.  

PubMed

Canine infectious respiratory disease (CIRD) is an acute, highly contagious disease complex caused by a variety of infectious agents. At present, the role of viral and bacterial components as primary or secondary pathogens in CIRD is not fully understood. The aim of this study was to investigate the prevalence of canine parainfluenza virus (CPIV), canine adenovirus type 2 (CAV-2), canine influenza virus (CIV), canine respiratory coronavirus (CRCoV), canine herpes virus-1 (CHV-1), canine distemper virus (CDV) and Bordetella bronchiseptica in dogs with CIRD and to compare the data with findings in healthy dogs. Sixty-one dogs with CIRD and 90 clinically healthy dogs from Southern Germany were prospectively enrolled in this study. Nasal and pharyngeal swabs were collected from all dogs and were analysed for CPIV, CAV-2, CIV, CRCoV, CHV-1, CDV, and B. bronchiseptica by real-time PCR. In dogs with acute respiratory signs, 37.7% tested positive for CPIV, 9.8% for CRCoV and 78.7% for B. bronchiseptica. Co-infections with more than one agent were detected in 47.9% of B. bronchiseptica-positive, 82.6% of CPIV-positive, and 100% of CRCoV-positive dogs. In clinically healthy dogs, 1.1% tested positive for CAV-2, 7.8% for CPIV and 45.6% for B. bronchiseptica. CPIV and B. bronchiseptica were detected significantly more often in dogs with CIRD than in clinically healthy dogs (P?pathogen) and were the most common infectious agents in dogs with CIRD in Southern Germany. Mixed infections with several pathogens were common. In conclusion, clinically healthy dogs can carry respiratory pathogens and could act as sources of infection for susceptible dogs. PMID:24980809

Schulz, B S; Kurz, S; Weber, K; Balzer, H-J; Hartmann, K

2014-09-01

376

Plant-pathogen interactions and elevated CO2: morphological changes in favour of pathogens  

Microsoft Academic Search

Crop losses caused by pests and weeds have been estimated at 42% worldwide, with plant pathogens responsible for almost $10 billion worth of damage in the USA in 1994 alone. Elevated carbon dioxide (ECO2) and associated climate change have the potential to accelerate plant pathogen evolution, which may, in turn, affect virulence. Plant- pathogen interactions under increasing CO2 concentrations have

Janice Ann Lake; Ruth Nicola Wade

2009-01-01

377

Protection of Mice against Lethal Infection with Highly Pathogenic H7N7 Influenza A Virus by Using a Recombinant Low-Pathogenicity Vaccine Strain  

Microsoft Academic Search

Received 8 April 2005\\/Accepted 30 June 2005 In 2003, an outbreak of highly pathogenic avian influenza occurred in the Netherlands. The avian H7N7 virus causing the outbreak was also detected in 88 humans suffering from conjunctivitis or mild respiratory symptoms and one person who died of pneumonia and acute respiratory distress syndrome. Here we describe a mouse model for lethal

Emmie de Wit; Vincent J. Munster; Monique I. J. Spronken; Theo M. Bestebroer; Chantal Baas; Walter E. P. Beyer; Guus F. Rimmelzwaan; Albert D. M. E. Osterhaus; Ron A. M. Fouchier

2005-01-01

378

Respiratory Care Therapist.  

ERIC Educational Resources Information Center

This document, which is designed for use in developing a tech prep competency profile for the occupation of respiratory care therapist, lists technical competencies and competency builders for 18 units pertinent to the health technologies cluster in general as well as those specific to the occupation of respiratory care therapist. The following…

Ohio State Univ., Columbus. Center on Education and Training for Employment.

379

Cardiovascular & Respiratory Modeling, Analysis & Control  

E-print Network

Cardiovascular & Respiratory Systems: Modeling, Analysis & Control J. J. Batzel, F. Kappel, D . . . . . . . . . . . . . . . . 36 1.7.3 Sensitivity analysis . . . . . . . . . . . . . . . . . . . 38 2 Respiratory Modeling 45 2.1 Respiratory Control Physiology . . . . . . . . . . . . . . . . . . 46 2.1.1 General features of respiration

Batzel, Jerry

380

Middle East Respiratory Syndrome (MERS)  

MedlinePLUS

Middle East Respiratory Syndrome Coronavirus; MERS-CoV; Novel coronavirus; nCoV ... Middle East Respiratory Syndrome (MERS) is a severe respiratory illness. It causes fever, coughing, and shortness of breath. About 30% of ...

381

Respiratory Disease and the Environment  

MedlinePLUS

... www.niehs.nih.gov Respiratory Disease and the Environment Respiratory diseases such as asthma, pneumonia, influenza and ... pollutants and tobacco smoke. The National Institute of Environmental Health Sciences sees respiratory disease as environmental disease. ...

382

Chitosan against cutaneous pathogens  

PubMed Central

Propionibacterium acnes and Staphylococcus aureus are cutaneous pathogens that have become increasingly resistant to antibiotics. We sought to determine if chitosan, a polymer of deacetylated chitin, could be used as a potential treatment against these bacteria. We found that higher molecular weight chitosan had superior antimicrobial properties compared to lower molecular weights, and that this activity occurred in a pH dependent manner. Electron and fluorescence microscopy revealed that chitosan forms aggregates and binds to the surface of bacteria, causing shrinkage of the bacterial membrane from the cell wall. Of special relevance, clinical isolates of P. acnes were vulnerable to chitosan, which could be combined with benzoyl peroxide for additive antibacterial effect. Chitosan also demonstrated significantly less cytotoxicity to monocytes than benzoyl peroxide. Overall, chitosan demonstrates many promising qualities for treatment of cutaneous pathogens. PMID:23829873

2013-01-01

383

Surveillance for upper respiratory tract disease and Mycoplasma in free-ranging gopher tortoises (Gopherus polyphemus) in Georgia, USA.  

PubMed

Abstract Upper respiratory tract disease (URTD) in the gopher tortoise (Gopherus polyphemus) is highly contagious and has been implicated in the reduction of populations throughout the range. With the exception of a few limited studies, the prevalence of URTD in Georgia, USA tortoise populations is poorly known. We found that exposure to Mycoplasma agassizii and Mycoplasma testudineum, associated with URTD, varied geographically among 11 Georgia tortoise populations. The prevalence of antibodies to M. agassizii in individual populations was either very low (0-3%, n=7 populations) or very high (96-100%, n=4 populations), whereas there was variation in the prevalence of antibodies to M. testudineum among populations (20-61%, n=10) with only one site being negative. Five sites had tortoises with antibodies to both pathogens, and these were the only sites where we observed tortoises with clinical signs consistent with URTD. We did not find tortoises with clinical signs of URTD at sites with tortoises with antibodies only to M. testudineum, which provides evidence that this organism may be of limited pathogenicity for gopher tortoises. Collectively, these data indicate that both M. agassizii and M. testudineum are present in Georgia populations of gopher tortoises and that clinical disease is apparent in populations where both pathogens are present. Additional research is needed to better understand the role of these two pathogens, and other potential pathogens, in the overall health of tortoise populations, especially if future conservation efforts involve translocation of tortoises. PMID:25098305

McGuire, Jessica L; Smith, Lora L; Guyer, Craig; Lockhart, J Mitchell; Lee, Gregory W; Yabsley, Michael J

2014-10-01

384

Phylogeny and Phenotypic Characterization of Pathogenic Cryptococcus Species and Closely Related Saprobic Taxa in the Tremellales ? †  

PubMed Central

The basidiomycetous yeasts Cryptococcus neoformans and Cryptococcus gattii are closely related sibling species that cause respiratory and neurological disease in humans and animals. Within these two recognized species, phylogenetic analysis reveals at least six cryptic species defined as molecular types (VNI/II/B, VNIV, VGI, VGII, VGIII, and VGIV) that comprise the pathogenic Cryptococcus species complex. These pathogenic species are clustered in the Filobasidiella clade within the order Tremellales. Previous studies have shown that the Filobasidiella clade also includes several saprobic fungi isolated from insect frass, but information evaluating the relatedness of the saprobes and pathogens within this cluster is limited. Here, the phylogeny encompassing a subset of species in the Tremellales lineage that clusters closely with the pathogenic Cryptococcus species complex was resolved by employing a multilocus sequencing approach for phylogenetic analysis. Six highly conserved genomic loci from 15 related basidiomycete species were sequenced, and the alignments from the concatenated gene sequences were evaluated with different tree-building criteria. Furthermore, these 15 species were subjected to virulence and phenotype assays to evaluate their pathogenic potential. These studies revealed that Cryptococcus amylolentus and Tsuchiyaea wingfieldii, two nonpathogenic sibling species, are the taxa most closely related to the pathogens C. neoformans and C. gattii and together with Filobasidiella depauperata form a Cryptococcus sensu stricto group. Five other saprobic yeast species form the Kwoniella clade, which appears to be a part of a more distantly related sensu lato group. This study establishes a foundation for future comparative genomic approaches that will provide insight into the structure, function, and evolution of the mating type locus, the transitions in modes of sexual reproduction, and the emergence of human pathogenic species from related or ancestral saprobic species. PMID:19151324

Findley, Keisha; Rodriguez-Carres, Marianela; Metin, Banu; Kroiss, Johannes; Fonseca, Álvaro; Vilgalys, Rytas; Heitman, Joseph

2009-01-01

385

WFDC2 (HE4): A potential role in the innate immunity of the oral cavity and respiratory tract and the development of adenocarcinomas of the lung  

PubMed Central

Background The Whey Acidic Protein domain is an evolutionarily conserved motif found in a number of proteins, the best studied of which are antiproteinases involved in the innate immune defence of multiple epithelia. We recently characterised the WFDC2 gene which encodes a two WAP domain-containing protein, initially suggested as a marker for epididymis, and showed that it is highly expressed in the lung and salivary gland. The precise location of WFDC2 protein in these sites has not been described. Methods We used immunohistochemistry to localise WFDC2 in normal tissues of the respiratory tract, naso- and oropharynx, as well as in chronically inflamed lung from Cystic Fibrosis and a range of pulmonary carcinomas. We have complemented these studies with molecular analysis of WFDC2 gene expression in primary human lung cell cultures. Results WFDC2 is expressed in some epithelial cells of the upper airways as well as in mucous cells and ducts of submucosal glands. No staining was seen in peripheral lung. Intense staining is found in major salivary glands and in minor glands of the nose, sinuses, posterior tongue and tonsil. Studies with the related protein Secretory Leukocyte Protease Inhibitor (SLPI) show that although both proteins are expressed in similar tissues, the precise cellular localisation differs. Significant increases in expression and localisation of WFDC2 are seen in patients with Cystic Fibrosis. SLPI expression was greatly reduced in the same samples. In cultures of tracheobronchial epithelial cells, expression of WFDC2 and SLPI are differentially regulated during differentiation yet WFDC2 is not induced by pro-inflammatory mediators. The majority of adenocarcinomas stain with WFDC2 whilst a significant minority of squamous, small cell and large cell carcinomas exhibit focal staining. There is no clear association with tumour grade. Conclusion We believe that these studies support the hypothesis that WFDC2 may be a component of the innate immune defences of the lung, nasal and oral cavities and suggest that WFDC2 functions in concert with related WAP domain containing proteins in epithelial host defence. We also suggest that WFDC2 re-expression in lung carcinomas may prove to be associated with tumour type and should be studied in further detail. PMID:16600032

Bingle, Lynne; Cross, Simon S; High, Alec S; Wallace, William A; Rassl, Doris; Yuan, Guanglu; Hellstrom, Ingegerd; Campos, Michael A; Bingle, Colin D

2006-01-01

386

Evidence for the Emergence of Non-O1 and Non-O139 Vibrio cholerae Strains with Pathogenic Potential by Exchange of O-Antigen Biosynthesis Regions  

Microsoft Academic Search

The novel epidemic strain Vibrio cholerae O139 Bengal originated from a seventh-pandemic O1 El Tor strain by antigenic shift resulting from homologous recombination-mediated exchange of O-antigen biosynthesis (wb*) clusters. Conservation of the genetic organization of wb* regions seen in other serogroups raised the possibility of the existence of pathogenic non-O1 and non-O139 V. cholerae strains that emerged by similar events.

Manrong Li; Toshio Shimada; J. Glenn Morris; Alexander Sulakvelidze; Shanmuga Sozhamannan

2002-01-01

387

The pathogenic potential of different pulsed-field gel electrophoresis types of Listeria monocytogenes strains isolated from food in Northeast Bosnia and Herzegovina.  

PubMed

Listeria monocytogenes is often present in meat and meat products that are sold in the area of northeast Bosnia and Herzegovina. The major objective of this study was to examine the virulence of L. monocytogenes strains isolated from these types of food in that geographic area. Polymerase chain reaction was used to detect eight genes responsible for virulence of this pathogen, namely, prfA, inlA, inlB, hly, plcA, plcB, actA, and mpl. All examined isolates were confirmed to possess the eight virulence genes. Ten different pulsed-field gel electrophoresis (PFGE) macrorestriction profiles were recognized among 19 L. monocytogenes strains after restriction with two different endonucleases (ApaI and AscI). The pathogenicity of three different PFGE types of L. monocytogenes was confirmed through in vivo tests, which were performed on female white mice (Pasteur strain), and it ranged from 3.55 × 10(8) LD50 to 1.58 × 10(10) LD50. All of the three different PFGE types of L. monocytogenes were regarded as moderately virulent in relation to the reference strain L. monocytogenes Scott A. This result might be one of the reasons for the absence of reported listeriosis in northeast Bosnia and Herzegovina, despite the high degree of food contamination with this pathogen. PMID:21612523

Hodži?, Snjezana; Huki?, Mirsada; Franciosa, Giovanna; Aureli, Paolo

2011-09-01

388