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1

Drug-resistant respiratory pathogens in Japan  

Microsoft Academic Search

\\u000a In order to investigate the trends of antimicrobial susceptibility in respiratory pathogens in Japan, the Japanese Society\\u000a of Chemotherapy (JSC) established a nationwide surveillance network in 2006. During the period from January to August, 2007,\\u000a 1,178 strains were collected from clinical specimens obtained from adult patients with well-diagnosed respiratory tract infections.\\u000a Susceptibility testing was evaluated for 1,108 strains (226 Staphylococcus

Tetsuya Matsumoto

2

Human metapneumovirus: a new respiratory pathogen  

Microsoft Academic Search

Human metapneumovirus is a recently recognized pathogen of acute respiratory tract infection (ARI) in children as well as\\u000a elderly and immunocompromised adults. The virus belongs to the family Paramyxoviridae, sub family Pneumovirinae and genus Metapneumovirus. Through genetic analysis it has been characterized into two groups A and B which are further divided into four sub-lineages.\\u000a The virus is difficult to

S. Broor; P. Bharaj; H. S. Chahar

2008-01-01

3

Validation of Syndromic Surveillance for Respiratory Pathogen Activity  

PubMed Central

Syndromic surveillance is increasingly used to signal unusual illness events. To validate data-source selection, we retrospectively investigated the extent to which 6 respiratory syndromes (based on different medical registries) reflected respiratory pathogen activity. These syndromes showed higher levels in winter, which corresponded with higher laboratory counts of Streptococcus pneumoniae, respiratory syncytial virus, and influenza virus. Multiple linear regression models indicated that most syndrome variations (up to 86%) can be explained by counts of respiratory pathogens. Absenteeism and pharmacy syndromes might reflect nonrespiratory conditions as well. We also observed systematic syndrome elevations in the fall, which were unexplained by pathogen counts but likely reflected rhinovirus activity. Earliest syndrome elevations were observed in absenteeism data, followed by hospital data (+1 week), pharmacy/general practitioner consultations (+2 weeks), and deaths/laboratory submissions (test requests) (+3 weeks). We conclude that these syndromes can be used for respiratory syndromic surveillance, since they reflect patterns in respiratory pathogen activity.

van Asten, Liselotte; van Pelt, Wilfrid; Nagelkerke, Nico J.D.; Verheij, Robert; de Neeling, Albert J.; Dekkers, Arnold; van der Sande, Marianne A.B.; van Vliet, Hans; Koopmans, Marion P.G.

2008-01-01

4

In vitro activity of ertapenem against selected respiratory pathogens  

Microsoft Academic Search

Objectives: The in vitro activity of ertapenem was evaluated in comparison to 21 selected agents against a large collection of recently isolated respiratory tract pathogens including: 180 Streptococcus pneumoniae, 100 Streptococcus pyogenes ,7 0Haemophilus influenzae ,7 0Moraxella catarrhalis, 100 methicillin-susceptible Staphylococcus aureus and 30 Klebsiella pneumoniae. Additional in vitro tests (time-kill curves with ertapenem alone and in combination with four

A. Marchese; L. Gualco; A. M. Schito; E. A. Debbia; G. C. Schito

2004-01-01

5

Viral and Bacterial Pathogens in Bovine Respiratory Disease in Finland  

PubMed Central

Pathogens causing bovine respiratory tract disease in Finland were investigated. Eighteen cattle herds with bovine respiratory disease were included. Five diseased calves from each farm were chosen for closer examination and tracheobronchial lavage. Blood samples were taken from the calves at the time of the investigation and from 86 calves 3–4 weeks later. In addition, 6–10 blood samples from animals of different ages were collected from each herd, resulting in 169 samples. Serum samples were tested for antibodies to bovine parainfluenza virus-3 (PIV-3), bovine respiratory syncytial virus (BRSV), bovine coronavirus (BCV), bovine adenovirus-3 (BAV-3) and bovine adenovirus-7 (BAV-7). About one third of the samples were also tested for antibodies to bovine virus diarrhoea virus (BVDV) with negative results. Bacteria were cultured from lavage fluid and in vitro susceptibility to selected antimicrobials was tested. According to serological findings, PIV-3, BAV-7, BAV-3, BCV and BRSV are common pathogens in Finnish cattle with respiratory problems. A titre rise especially for BAV-7 and BAV-3, the dual growth of Mycoplasma dispar and Pasteurella multocida, were typical findings in diseased calves. Pasteurella sp. strains showed no resistance to tested antimicrobials. Mycoplasma bovis and Mannheimia haemolytica were not found.

Hartel, H; Nikunen, S; Neuvonen, E; Tanskanen, R; Kivela, S-L; Aho, P; Soveri, T; Saloniemi, H

2004-01-01

6

Pathogenic potential of Campylobacter ureolyticus.  

PubMed

The recent detection and isolation of the aflagellate Campylobacter ureolyticus (previously known as Bacteroides ureolyticus) from intestinal biopsy specimens and fecal samples of children with newly diagnosed Crohn's disease led us to investigate the pathogenic potential of this bacterium. Adherence and gentamicin protection assays were employed to quantify the levels of adherence to and invasion into host cells. C. ureolyticus UNSWCD was able to adhere to the Caco-2 intestinal epithelial cell line with a value of 5.341% ± 0.74% but was not able to invade the Caco-2 cells. The addition of two proinflammatory cytokines, tumor necrosis factor alpha (TNF-?) and gamma interferon (IFN-?), to the cell line did not affect attachment or invasion, with attachment levels being 4.156% ± 0.61% (P = 0.270) for TNF-? and 6.472% ± 0.61% (P = 0.235) for IFN-?. Scanning electron microscopy visually confirmed attachment and revealed that C. ureolyticus UNSWCD colonizes and adheres to intestinal cells, inducing cellular damage and microvillus degradation. Purification and identification of the C. ureolyticus UNSWCD secretome detected a total of 111 proteins, from which 29 were bioinformatically predicted to be secretory proteins. Functional classification revealed three putative virulence and colonization factors: the surface antigen CjaA, an outer membrane fibronectin binding protein, and an S-layer RTX toxin. These results suggest that C. ureolyticus has the potential to be a pathogen of the gastrointestinal tract. PMID:22124656

Burgos-Portugal, Jose A; Kaakoush, Nadeem O; Raftery, Mark J; Mitchell, Hazel M

2012-02-01

7

Screening of respiratory pathogens by Respiratory Multi Well System (MWS) r-gene™ assay in hospitalized patients.  

PubMed

Novel respiratory viruses have been identified as possible agents of upper and lower respiratory tract infections. Multiplex real-time PCRs have been developed to identify clinically relevant respiratory pathogens. In this study, 178 respiratory samples already screened for influenza virus types A and B by Flu A/B ASR real-time PCR kit were retrospectively analyzed with the Respiratory Multi Well System (MWS) r-gene™ real-time PCR kit which detects a wide spectrum of respiratory pathogens. The goal was to demonstrate the importance of a wide spectrum screening compared to a single diagnostic request. The Flu A/B ASR kit detected influenza B virus in 1.7% of the samples (3/178) and no influenza A virus. The MWS r-gene™ kit detected influenza virus in 6.7% (12/178) of samples (0.6% influenza A, and 6.2% influenza B), while the overall detection rate for respiratory pathogens was 54% (96/178). Co-infections were detected in 8/178 (4.5%) samples. Adenovirus was the infectious agent detected most frequently, followed by respiratory syncytial virus. The risk of being infected by respiratory syncytial virus is almost threefold higher in patients older than 65 years compared to the younger age group (OR:2.7, 95% CI: 1.2-6.2). Wide spectrum screening of respiratory pathogens by real-time PCR is an effective means of detecting clinically relevant viral pathogens. PMID:24858651

Paba, Pierpaolo; Farchi, Francesca; Mortati, Erika; Ciccozzi, Massimo; Piperno, Micol; Perno, Carlo Federico; Ciotti, Marco

2014-04-01

8

Frequency of pathogen occurrence and antimicrobial susceptibility among community-acquired respiratory tract infections in the respiratory surveillance program study: microbiology from the medical office practice environment  

Microsoft Academic Search

Continuing problems of antimicrobial resistance have prompted the initiation of several surveillance programs. Few, if any, of these programs focus on community-acquired respiratory tract infections seen in routine office-based practices. The Respiratory Surveillance Program (RESP; 1999–2000) in 674 community-based physician office practices in the United States determined the frequency of potential bacterial pathogens including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella

Michael A Pfaller; Anton F Ehrhardt; Ronald N Jones

2001-01-01

9

Potential Occupational Causes of Cancer. 1. The Respiratory Tract.  

National Technical Information Service (NTIS)

Contents: Epidemiology and etiology of potential occupational cancer of the respiratory tract; Carcinogenicity studies of occupation-related agents purported to cause respiratory tract cancer; Prevention of potential occupational cancer of the respiratory...

1986-01-01

10

Using a Resequencing Microarray as a Multiple Respiratory Pathogen Detection Assay? †  

PubMed Central

Simultaneous testing for detection of infectious pathogens that cause similar symptoms (e.g., acute respiratory infections) is invaluable for patient treatment, outbreak prevention, and efficient use of antibiotic and antiviral agents. In addition, such testing may provide information regarding possible coinfections or induced secondary infections, such as virally induced bacterial infections. Furthermore, in many cases, detection of a pathogen requires more than genus/species-level resolution, since harmful agents (e.g., avian influenza virus) are grouped with other, relatively benign common agents, and for every pathogen, finer resolution is useful to allow tracking of the location and nature of mutations leading to strain variations. In this study, a previously developed resequencing microarray that has been demonstrated to have these capabilities was further developed to provide individual detection sensitivity ranging from 101 to 103 genomic copies for more than 26 respiratory pathogens while still retaining the ability to detect and differentiate between close genetic neighbors. In addition, the study demonstrated that this system allows unambiguous and reproducible sequence-based strain identification of the mixed pathogens. Successful proof-of-concept experiments using clinical specimens show that this approach is potentially very useful for both diagnostics and epidemic surveillance.

Lin, Baochuan; Blaney, Kate M.; Malanoski, Anthony P.; Ligler, Adam G.; Schnur, Joel M.; Metzgar, David; Russell, Kevin L.; Stenger, David A.

2007-01-01

11

Beneficial effects of probiotics in upper respiratory tract infections and their mechanical actions to antagonize pathogens.  

PubMed

Probiotics are live micro-organisms with beneficial effects on human health, which have the ability to counteract infections at different locations of the body. Clinical trials have shown that probiotics can be used as preventive and therapeutic agents in upper respiratory tract infections (URTIs) and otitis. Their mechanical properties allow them to aggregate and to compete with pathogens for nutrients, space and attachment to host cells. Consequently, they can directly antagonize pathogens and thus exert beneficial effects without directly affecting the metabolism of the host. An overview of the probiotics with such traits, tested up to date in clinical trials for the prevention or treatment of URTIs and otitis, is presented in this review. Their mechanical properties in the respiratory tract as well as at other locations are also cited. Species with interesting in vitro properties towards pharyngeal cells or against common respiratory pathogens have also been included. The potential safety risks of the cited species are then discussed. This review could be of help in the screening of probiotic strains with specific mechanical properties susceptible to have positive effects in clinical trials against URTIs. PMID:22788970

Popova, M; Molimard, P; Courau, S; Crociani, J; Dufour, C; Le Vacon, F; Carton, T

2012-12-01

12

Moxifloxacin sensitivity of respiratory pathogens in the United Kingdom.  

PubMed

The in vitro activity of moxifloxacin and comparator agents against respiratory isolates from a range of geographically distinct centres around the United Kingdom was investigated in the following study. Clinical isolates of Streptococcus pneumoniae (n = 257), Haemophilus influenzae (n = 399) and Moraxella catarrhalis (n = 253) were obtained between March 1998 and April 1999 from nine centres in the United Kingdom. Sensitivity was determined by testing each isolate for its minimum inhibitory concentration (MIC) by agar dilution. Against Streptococcus pneumoniae moxifloxacin and grepafloxacin were the most active (MIC90 = 0.25 mg/l). Trovafloxacin and sparfloxacin were the next most active (MIC90 = 0.5 mg/l) followed by levofloxacin and ciprofloxacin. MIC90 values of the six fluoroquinolones versus H. influenzae ranged from <0.0039 mg/l to 0.0625 mg/l and from <0.0039 mg/l to 0.5 mg/l for M. catarrhalis. The rank order of activity of the fluoroquinolones versus H. influenzae was moxifloxacin = trovafloxacin = grepafloxacin = sparfloxacin > ciprofloxacin > levofloxacin. Against M. catarrhalis the lowest MIC90 was that of grepafloxacin at 0.0625 mg/l followed by moxifloxacin, sparfloxacin, levofloxacin and ciprofloxacin. Trovafloxacin demonstrated the highest MIC90 at 0.5 mg/l. These results demonstrate that moxifloxacin has superior in vitro activity against respiratory tract pathogens than any other comparator quinolones available for clinical use. PMID:11892894

Dorai-John, T; Thomson, C J; Amyes, S G

2002-02-01

13

Respiratory pathogens in dental plaque of hospitalized patients with chronic lung diseases  

Microsoft Academic Search

Bacterial cultivation studies have shown that dental plaque is a reservoir for respiratory pathogens in intensive care unit patients and in elderly who are debilitated, hospitalized or in a nursing home, placing them at risk of bacterial pneumonia. No information is available, however, concerning dental plaque as a reservoir of putative respiratory pathogens in hospitalized patients with chronic lung diseases.

Andreea C. Didilescu; Nils Skaug; Constantin Marica; Cristian Didilescu

2005-01-01

14

Evaluation of multiplexed PCR and liquid-phase array for identification of respiratory fungal pathogens.  

PubMed

Invasive fungal infections are the cause of serious morbidity and high mortality in immunocompromised patients. Early laboratory diagnostic options remain limited; however, rapid detection and accurate identification may improve outcome. Herein, multiplexed PCR followed by liquid-phase array was evaluated for detection and identification of common respiratory fungal pathogens, including Aspergillus fumigatus, Rhizopus microsporus, Scedosporium apiospermum and Fusarium solani. The limit of detection ranged 0.1-1 ng of DNA, depending on the fungus being tested. Primer cross-reactivity was seen for some fungi: Aspergillus flavus primers detected Aspergillus oryzae; Scedosporium apiospermum primers detected Paecilomyces lilacinus, and Aspergillus terreus primers detected S. apiospermum. PCR followed by liquid-phase array is potentially useful for the identification of clinically relevant fungal pathogens. PMID:22435876

Buelow, Daelynn R; Gu, Zhengming; Walsh, Thomas J; Hayden, Randall T

2012-10-01

15

Associations between Pathogens in the Upper Respiratory Tract of Young Children: Interplay between Viruses and Bacteria  

PubMed Central

Background High rates of potentially pathogenic bacteria and respiratory viruses can be detected in the upper respiratory tract of healthy children. Investigating presence of and associations between these pathogens in healthy individuals is still a rather unexplored field of research, but may have implications for interpreting findings during disease. Methodology/Principal Findings We selected 986 nasopharyngeal samples from 433 6- to 24-month-old healthy children that had participated in a randomized controlled trial. We determined the presence of 20 common respiratory viruses using real-time PCR. Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus were identified by conventional culture methods. Information on risk factors was obtained by questionnaires. We performed multivariate logistic regression analyses followed by partial correlation analysis to identify the overall pattern of associations. S. pneumoniae colonization was positively associated with the presence of H. influenzae (adjusted odds ratio 1.60, 95% confidence interval 1.18–2.16), M. catarrhalis (1.78, 1.29–2.47), human rhinoviruses (1.63, 1.19–2.22) and enteroviruses (1.97, 1.26–3.10), and negatively associated with S. aureus presence (0.59, 0.35–0.98). H. influenzae was positively associated with human rhinoviruses (1.63, 1.22–2.18) and respiratory syncytial viruses (2.78, 1.06–7.28). M. catarrhalis colonization was positively associated with coronaviruses (1.99, 1.01–3.93) and adenoviruses (3.69, 1.29–10.56), and negatively with S. aureus carriage (0.42, 0.25–0.69). We observed a strong positive association between S. aureus and influenza viruses (4.87, 1.59–14.89). In addition, human rhinoviruses and enteroviruses were positively correlated (2.40, 1.66–3.47), as were enteroviruses and human bocavirus, WU polyomavirus, parainfluenza viruses, and human parechovirus. A negative association was observed between human rhinoviruses and coronaviruses. Conclusions/Significance Our data revealed high viral and bacterial prevalence rates and distinct bacterial-bacterial, viral-bacterial and viral-viral associations in healthy children, hinting towards the complexity and potential dynamics of microbial communities in the upper respiratory tract. This warrants careful consideration when associating microbial presence with specific respiratory diseases.

van den Bergh, Menno R.; Biesbroek, Giske; Rossen, John W. A.; de Steenhuijsen Piters, Wouter A. A.; Bosch, Astrid A. T. M.; van Gils, Elske J. M.; Wang, Xinhui; Boonacker, Chantal W. B.; Veenhoven, Reinier H.; Bruin, Jacob P.

2012-01-01

16

Pharmacodynamics of Telithromycin In Vitro against Respiratory Tract Pathogens  

PubMed Central

Telithromycin (HMR 3647) is a new ketolide that belongs to a new class of semisynthetic 14-membered-ring macrolides which have expanded activity against multidrug-resistant gram-positive bacteria. The aim of the present study was to investigate different basic pharmacodynamic properties of this new compound. The following studies of telithromycin were performed: (i) studies of the rate and extent of killing of respiratory tract pathogens with different susceptibilities to erythromycin and penicillin exposed to a fixed concentration that corresponds to a dose of 800 mg in humans, (ii) studies of the rate and extent of killing of telithromycin at five different concentrations, (iii) studies of the rate and extent of killing of the same pathogens at three different inocula, (iv) studies of the postantibiotic effect and the postantibiotic sub-MIC effect of telithromycin, and (v) determination of the rate and extent of killing of telithromycin in an in vitro kinetic model. In conclusion, telithromycin exerted an extremely fast killing of all strains of Streptococcus pneumoniae both with static concentrations and in the in vitro kinetic model. A slower killing of the strains of Streptococcus pyogenes was noted, with regrowth in the kinetic model of a macrolide-lincosamide-streptogramin B-inducible strain. The strains of Haemophilus influenzae were not killed at all at a concentration of 0.6 mg/liter due to high MICs. A time-dependent killing was seen for all strains. No inoculum effect was seen for the strains of S. pneumoniae, with a 99.9% reduction in the numbers of CFU for all inocula at both 8 h and 24 h. The killing of the strains of S. pyogenes was reduced by 1 log10 CFU at 8 h and 2 to 3 log10 CFU at 24 h when the two lower inocula were used but not at all at 8 and 24 h when the highest inoculum was used. For both of the H. influenzae strains there was an inoculum effect, with 1 to 2 log10 CFU less killing for the inoculum of 108 CFU/ml in comparison to that for the inoculum of 106 CFU/ml. Overall, telithromycin exhibited long postantibiotic effects and postantibiotic sub-MIC effects for all strains investigated.

Odenholt, Inga; Lowdin, Elisabeth; Cars, Otto

2001-01-01

17

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.

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

18

Using a Resequencing Microarray as a Multiple Respiratory Pathogen Detection Assay  

Microsoft Academic Search

Simultaneous testing for detection of infectious pathogens that cause similar symptoms (e.g., acute respiratory infections) is invaluable for patient treatment, outbreak prevention, and efficient use of antibiotic and antiviral agents. In addition, such testing may provide information regarding possible coinfections or induced secondary infections, such as virally induced bacterial infections. Furthermore, in many cases, detection of a pathogen requires more

Baochuan Lin; Kate M. Blaney; Anthony P. Malanoski; Adam G. Ligler; Joel M. Schnur; David Metzgar; Kevin L. Russell; David A. Stenger

2007-01-01

19

Selection of resistant variants of respiratory pathogens by quinolones  

Microsoft Academic Search

Quinolones are widely used in the treatment of respiratory tract infections. However, some disquiet has been expressed over using quinolones for community-acquired pneumonia since their activity is generally rather poor against Streptococcus pneumoniae. In addition, it is known that resistant variants emerge at a fairly high frequency during exposure of Enterobacteriaceae to quinolones; if this also occurred during quinolone treatment

A. M Sefton; J. P Maskell; J. D Williams

1999-01-01

20

Diagnosis of atypical pathogens in patients hospitalized with community-acquired respiratory infection.  

PubMed

The object of our study was to determine the proportion of atypical respiratory pathogens among patients hospitalized with a community-acquired respiratory infection. From September 1997 to May 1999, 159 patients (57% male, median age 55, range 1-88 y) admitted to 3 regional hospitals for a community acquired respiratory infection, were enrolled in the study. Microbiological diagnosis for the atypical pathogens Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila was performed with PCR on a throat swab, sputum and/or broncho alveolar lavage (BAL). In addition, Legionella species other than L. pneumophila (L. non-pneumophila species) were detected by PCR. Two serum samples were collected and processed for M. pneumoniae and C. pneumoniae serology. In total, 27 patients (17%) were diagnosed with an atypical pathogen. Infection with M. pneumoniae was detected in 19 patients (12%) (PCR positive n = 7), with C. pneumoniae in 5 patients (3%) (PCR positive n = 0) and with L. pneumophila in 4 patients (2.5%) (PCR positive n = 4). In 54 (34%) patients routine microbiological investigations revealed aetiological agents other than the 3 atypical pathogens, the most frequently diagnosed pathogens being Streptococcus pneumoniae (n = 18), Haemophilus influenzae (n = 17), Gram-negative rods (n = 13), Moraxella catarrhalis (n = 6) and Staphylococcus aureus (n = 6). More than 1 pathogen was found in 13 patients. Atypical pathogens were found more often in the young age group (0-18 y), in contrast to bacterial pathogens that were found more often in the older age groups (> or = 65 y). Atypical pathogens were found less often in patients with a clinical presentation of atypical pneumonia. Legionella species other than L. pneumophila were found by PCR in 13 patients (8%), and in 6 patients in combination with another pathogen. An atypical pathogen (M. pneumoniae, C. pneumoniae or L. pneumophila) was found in 17% of the patients hospitalized with a community acquired respiratory infection, predominantly in the young age group. The role of Legionella non-pneumophila species as pathogen in community acquired respiratory infection needs to be determined. The clinical presentation does not predict the type of pathogen found. PMID:15198183

Schneeberger, Peter M; Dorigo-Zetsma, J Wendeline; van der Zee, Anneke; van Bon, Marion; van Opstal, Jean-Louis

2004-01-01

21

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.

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

22

Reverse transcription-PCR-electrospray ionization mass spectrometry for rapid detection of biothreat and common respiratory pathogens.  

PubMed

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

2013-10-01

23

Identification of Upper Respiratory Tract Pathogens Using Electrochemical Detection on an Oligonucleotide Microarray  

Microsoft Academic Search

Bacterial and viral upper respiratory infections (URI) produce highly variable clinical symptoms that cannot be used to identify the etiologic agent. Proper treatment, however, depends on correct identification of the pathogen involved as antibiotics provide little or no benefit with viral infections. Here we describe a rapid and sensitive genotyping assay and microarray for URI identification using standard amplification and

Michael J. Lodes; Dominic Suciu; Jodi L. Wilmoth; Marty Ross; Sandra Munro; Kim Dix; Karen Bernards; Axel G. Stöver; Miguel Quintana; Naomi Iihoshi; Wanda J. Lyon; David L. Danley; Andrew McShea; Maurizio Del Poeta

2007-01-01

24

In Vitro and In Vivo Activities of LB 10827, a New Oral Cephalosporin, against Respiratory Pathogens  

Microsoft Academic Search

The in vitro antibacterial activities of LB 10827, a new oral cephalosporin, against common respiratory tract pathogens were compared with those of six b-lactams (cefdinir, cefuroxime, cefprozil, penicillin G, amoxicillin- clavulanate, and ampicillin), two quinolones (trovafloxacin and ciprofloxacin), and one macrolide (clarithro- mycin). The MIC of LB 10827 at which 90% of the penicillin-resistant strains of Streptococcus pneumoniae tested were

KYONG-SOOK PAEK; MU-YONG KIM; CHANG-SEOK LEE; HASIK YOUN

2000-01-01

25

Complete Genome Sequence of a Novel Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Variant  

PubMed Central

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.

Wang, Lianghai; Hou, Jun; Zhang, Hexiao

2012-01-01

26

The impact of emotion on respiratory-related evoked potentials  

PubMed Central

Emotion influences the perception of respiratory sensations, although the specific mechanism underlying this modulation is not yet clear. We examined the impact of viewing pleasant, neutral, and unpleasant affective pictures on the respiratory-related evoked potential (RREP) elicited by a short inspiratory occlusion in healthy volunteers. Reduced P3 amplitude of the RREP was found for respiratory probes presented when viewing pleasant or unpleasant series, when compared to those presented during the neutral series. Earlier RREP components, such as Nf, P1, N1, and P2, showed no modulation by emotion. The results suggest that emotion impacts the perception of respiratory sensations by reducing the attentional resources available for processing afferent respiratory sensory signals.

von Leupoldt, Andreas; Vovk, Andrea; Bradley, Margaret M.; Keil, Andreas; Lang, Peter J.; Davenport, Paul W.

2013-01-01

27

Successful nanolitre real-time PCR detection of respiratory pathogens in clinical specimens.  

PubMed

We performed a proof-of-concept study to determine if human pathogens could be detected in clinical specimens using nanolitre-volume real-time PCR. Nanolitre PCR for Bordetella pertussis/B. parapertussis and respiratory syncytial virus (RSV) was performed on nasopharyngeal specimens and results compared with conventional methods. B. pertussis/B. parapertussis nanolitre PCR detection was 100% sensitive (20/20; 95% CI, 84-100%) and 100% specific (26/26; 95% CI, 87-100%). RSV nanolitre PCR was also 100% sensitive (21/21; 95% CI, 85-100%) and specific (25/25; 95%, CI 87-100%). Respiratory pathogens can be successfully detected in clinical specimens using nanolitre-volume PCR. PMID:22630162

Slinger, R; Moldovan, I; Barrowman, N; Chan, F

2012-08-01

28

Piracy of adhesins: attachment of superinfecting pathogens to respiratory cilia by secreted adhesins of Bordetella pertussis.  

PubMed

Two proteins secreted by Bordetella pertussis are known to mediate adherence of these bacteria to mammalian respiratory cilia. When either ciliated cells or other pathogenic bacteria were pretreated with these adhesins, Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus acquired the ability to adhere to cilia in vitro and in vivo. Such piracy of adhesins may contribute to superinfection in mucosal diseases such as whooping cough. PMID:2877952

Tuomanen, E

1986-12-01

29

Piracy of adhesins: attachment of superinfecting pathogens to respiratory cilia by secreted adhesins of Bordetella pertussis.  

PubMed Central

Two proteins secreted by Bordetella pertussis are known to mediate adherence of these bacteria to mammalian respiratory cilia. When either ciliated cells or other pathogenic bacteria were pretreated with these adhesins, Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus acquired the ability to adhere to cilia in vitro and in vivo. Such piracy of adhesins may contribute to superinfection in mucosal diseases such as whooping cough. Images

Tuomanen, E

1986-01-01

30

Association of serum Clara cell protein CC16 with respiratory infections and immune response to respiratory pathogens in elite athletes  

PubMed Central

Background Respiratory epithelium integrity impairment caused by intensive exercise may lead to exercise-induced bronchoconstriction. Clara cell protein (CC16) has anti-inflammatory properties and its serum level reflects changes in epithelium integrity and airway inflammation. This study aimed to investigate serum CC16 in elite athletes and to seek associations of CC16 with asthma or allergy, respiratory tract infections (RTIs) and immune response to respiratory pathogens. Methods The study was performed in 203 Olympic athletes. Control groups comprised 53 healthy subjects and 49 mild allergic asthmatics. Serum levels of CC16 and IgG against respiratory viruses and Mycoplasma pneumoniae were assessed. Allergy questionnaire for athletes was used to determine symptoms and exercise pattern. Current versions of ARIA and GINA guidelines were used when diagnosing allergic rhinitis and asthma, respectively. Results Asthma was diagnosed in 13.3% athletes, of whom 55.6% had concomitant allergic rhinitis. Allergic rhinitis without asthma was diagnosed in 14.8% of athletes. Mean CC16 concentration was significantly lower in athletes versus healthy controls and mild asthmatics. Athletes reporting frequent RTIs had significantly lower serum CC16 and the risk of frequent RTIs was more than 2-fold higher in athletes with low serum CC16 (defined as equal to or less than 4.99 ng/ml). Athletes had significantly higher anti-adenovirus IgG than healthy controls while only non-atopic athletes had anti-parainfluenza virus IgG significantly lower than controls. In all athletes weak correlation of serum CC16 and anti-parainfluenza virus IgG was present (R?=?0.20, p?respiratory syncytial virus (R?=?0.29, p?=?0.009), parainfluenza virus (R?=?0.31, p?=?0.01) and adenovirus (R?=?0.27, p?=?0.02) were seen as well. Conclusions Regular high-load exercise is associated with decrease in serum CC16 levels. Athletes with decreased CC16 are more susceptible to respiratory infections. Atopy may be an additional factor modifying susceptibility to infections in subjects performing regular high-load exercise.

2014-01-01

31

Antimicrobial resistance trends among community-acquired respiratory tract pathogens in Greece, 2009-2012.  

PubMed

The aim of the present study was to determine the antimicrobial resistance trends of respiratory tract pathogens isolated from patients with community-acquired respiratory tract infections (CARTIs) in Crete, Greece, over a 4-year period (2009-2012). A total of 588 community-acquired respiratory pathogens were isolated during the study period. Streptococcus pneumoniae was the most common organism responsible for 44.4% of CARTIs, followed by Haemophilus influenzae (44.2%) and Moraxella catarrhalis (11.4%). Among S. pneumoniae, the prevalence of isolates with intermediate- and high-level resistance to penicillin was 27.2% and 12.3%, respectively. Macrolide resistance slightly decreased from 29.4% over the period 2009-2010 to 28.8% over the period 2011-2012. Multiresistance was observed among 56 (54.4%) penicillin nonsusceptible isolates. A nonsignificant increase in resistance of H. influenzae isolates was noted for ? -lactams, cotrimoxazole, and tetracycline. Among the 67 M. catarrhalis tested, 32 produced beta-lactamase and were resistant to ampicillin. Macrolide resistance decreased over the study period. All isolates were susceptible to amoxicillin + clavulanic acid, chloramphenicol, rifampicin, and the fluoroquinolones. Although a decreasing trend in the prevalence of resistance of the three most common pathogens involved in CARTIs was noted, continuous surveillance of antimicrobial susceptibility at the local and national level remains important, in order to guide appropriate empirical antimicrobial therapy. PMID:24592201

Maraki, Sofia; Papadakis, Ioannis S

2014-01-01

32

Antimicrobial Resistance Trends among Community-Acquired Respiratory Tract Pathogens in Greece, 2009-2012  

PubMed Central

The aim of the present study was to determine the antimicrobial resistance trends of respiratory tract pathogens isolated from patients with community-acquired respiratory tract infections (CARTIs) in Crete, Greece, over a 4-year period (2009–2012). A total of 588 community-acquired respiratory pathogens were isolated during the study period. Streptococcus pneumoniae was the most common organism responsible for 44.4% of CARTIs, followed by Haemophilus influenzae (44.2%) and Moraxella catarrhalis (11.4%). Among S. pneumoniae, the prevalence of isolates with intermediate- and high-level resistance to penicillin was 27.2% and 12.3%, respectively. Macrolide resistance slightly decreased from 29.4% over the period 2009-2010 to 28.8% over the period 2011-2012. Multiresistance was observed among 56 (54.4%) penicillin nonsusceptible isolates. A nonsignificant increase in resistance of H. influenzae isolates was noted for ?-lactams, cotrimoxazole, and tetracycline. Among the 67 M. catarrhalis tested, 32 produced beta-lactamase and were resistant to ampicillin. Macrolide resistance decreased over the study period. All isolates were susceptible to amoxicillin + clavulanic acid, chloramphenicol, rifampicin, and the fluoroquinolones. Although a decreasing trend in the prevalence of resistance of the three most common pathogens involved in CARTIs was noted, continuous surveillance of antimicrobial susceptibility at the local and national level remains important, in order to guide appropriate empirical antimicrobial therapy.

Maraki, Sofia; Papadakis, Ioannis S.

2014-01-01

33

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.

2014-01-01

34

Pathogenicity and molecular characteristics of infectious bronchitis virus (IBV) strains isolated from broilers showing diarrhoea and respiratory disease.  

PubMed

Abstract 1. The possibility that infectious bronchitis virus (IBV) variants isolated from broilers with enteric and respiratory problems have a different tropism and pathological outcome from those IBV strains causing classical respiratory disease was investigated. 2. IBV variants were isolated from broiler flocks with enteric and respiratory problems in two regions of Brazil. The USP-10 isolate, of enteric origin, was inoculated via the oral oroculonasal routes into IBV-antibody-free broilers and specific pathogen-free (SPF) chickens to determine tissue tropism and pathogenicity and compared with an IBV variant (USP-50) isolated from chickens showing signs of respiratory disease only. 3. Both USP-10 and USP-50 strains caused similar pathological patterns by either route of inoculation. Both variants were detected in respiratory and non-respiratory tissues, including the kidney, intestine and testis. 4. Broilers were more susceptible to infection than SPF chickens, and seroconversion was detected in all of the chicks. PMID:24678626

Chacón, J L; Assayag, M S; Revolledo, L; Astolfi-Ferreira, C S; Vejarano, M P; Jones, R C; Piantino Ferreira, A J

2014-06-01

35

Pandemic influenza A (H1N1) and other respiratory pathogens: clinical insights - from epidemiology to treatment  

Microsoft Academic Search

This thesis contains clinical studies on 2009 pandemic influenza A (H1N1) and other respiratory pathogens. Chapter 1 is a general introduction. Chapter 2 comprises three studies on epidemiology. The first describes epidemiological characteristics of 964 adult outpatients who presented with influenza-like signs and symptoms during the 2009 H1N1 pandemic. Respiratory pathogens were detected in 41% and pandemic influenza A (H1N1)

P. M. Smit

2012-01-01

36

Antibacterial activity of carbapenems against clinical isolates of respiratory bacterial pathogens in the northeastern region of Japan in 2007  

Microsoft Academic Search

As the increasing prevalence of resistant strains of respiratory bacterial pathogens has recently been reported, continuous\\u000a monitoring of the susceptibility of clinical isolates to antibacterial agents is important. We performed a surveillance study\\u000a focusing on the susceptibility of major respiratory bacterial pathogens in the northeastern region of Japan to carbapenems\\u000a and control drugs. A total of 168 bacterial strains isolated

Kazunori GomiShigeru; Shigeru Fujimura; Katsuhiro Fuse; Hidenari Takane; Yoshihisa Nakano; Yasuko Kariya; Toshiaki Kikuchi; Iku Kurokawa; Yutaka Tokue; Akira Watanabe

2011-01-01

37

Bacterial 'Cell' Phones: Do cell phones carry potential pathogens?  

Microsoft Academic Search

Cell phones are important companions for professionals especially health care workers (HCWs) for better communication in hospital. The present study compared the nature of the growth of potentially pathogenic bacterial flora on cell phones in hospital and community. 75% cell phones from both the categories grew at least one potentially pathogenic organism. Cell phones from HCWs grew significantly more potential

Kiran Chawla; Chiranjay Mukhopadhayay; Bimala Gurung; Priya Bhate; Indira Bairy

38

Microbiological and pathological examination of fatal calf pneumonia cases induced by bacterial and viral respiratory pathogens.  

PubMed

The infectious origin of fatal cases of calf pneumonia was studied in 48 calves from 27 different herds on postmortem examination. Lung tissue samples were examined by pathological, histological, bacterial culture, virus isolation and immunohistochemical methods for the detection of viral and bacterial infections. Pneumonia was diagnosed in 47/48 cases and infectious agents were found in 40/47 (85%) of those cases. The presence of multiple respiratory pathogens in 23/40 (57.5%) cases indicated the complex origin of fatal calf pneumonia. The most important respiratory pathogens were Mannheimia-Pasteurella in 36/40 (90%) cases, followed by Arcanobacterium pyogenes in 16/40 (40%) cases, Mycoplasma bovis in 12/40 (30%) cases, and bovine respiratory syncytial virus in 4/40 (10%) cases. Histophilus somni was detected in 2/40 (5%) cases, while bovine herpesvirus-1, bovine viral diarrhoea virus and parainfluenza virus-3 were each found in 1/40 (2.5%) case. Mastadenovirus, bovine coronavirus, influenza A virus or Chlamydiaceae were not detected. PMID:20713325

Szeredi, Levente; Jánosi, Szilárd; Pálfi, Vilmos

2010-09-01

39

Potential role of periodontal infection in respiratory diseases-a review  

PubMed Central

Respiratory diseases are responsible for a significant number of deaths and considerable suffering in humans. Accumulating evidence suggests that oral disorders, particularly periodontal disease, may influence the course of respiratory infections like bacterial pneumonia and chronic obstructive pulmonary disease (COPD). Oral periodontopathic bacteria can be aspirated into the lung causing aspiration pneumonia. The teeth may also serve as a reservoir for respiratory pathogen colonization and subsequent nosocomial pneumonia. The overreaction of the inflammatory process that leads to the destruction of the connective tissue is present in both periodontal disease and emphysema. This overreaction may explain the association between periodontal disease and chronic obstructive pulmonary disease. The mechanisms of infection could be the aspiration into the lung of oral pathogens capable of causing pneumonia, colonization of dental plaque by respiratory pathogens followed by aspiration, or facilitation of colonization of the upper airway by pulmonary pathogens by periodontal pathogens. The present article briefly reviews the epidemiologic evidence & role of periodontopathogens in causing respiratory infections.

Bansal, M; Khatri, M; Taneja, V

2013-01-01

40

Prevalence of respiratory pathogens in diseased, non-vaccinated, routinely medicated veal calves.  

PubMed

The prevalence of respiratory pathogens in diseased veal calves was determined in 24 respiratory disease outbreaks in 15 herds in Belgium. Bacteria were cultured from nasopharyngeal swabs and seroconversion against viruses and Mycoplasma bovis was determined on paired sera. At the individual calf level, Mycoplasma species, Mannheimia haemolytica and Pasteurella multocida, were isolated from 70.5 per cent, 21.5 per cent and 26.0 per cent of swabs, respectively. At the herd level, the presence of M bovis could be confirmed in 84.6 per cent of the herds examined. Seroconversion against bovine viral diarrhoea virus (BVDV) was present in 71.4 per cent of herds, parainfluenzavirus type 3 in 53.3 per cent, bovine respiratory syncytial virus in 40.0 per cent, bovine adenovirus type 3 in 46.7 per cent, bovine coronavirus in 30.0 per cent, and bovine herpesvirus type 1 in 26.7 per cent. At postmortem examination, Mycoplasma species could be cultured from 61.9 per cent of pneumonic lungs (n=21). Sixty per cent of calves tested were positive for BVDV (n=20), and 20.0 per cent were positive for bovine respiratory syncytial virus (n=16). PMID:21831999

Pardon, B; De Bleecker, K; Dewulf, J; Callens, J; Boyen, F; Catry, B; Deprez, P

2011-09-10

41

Motor evoked potentials of the respiratory muscles in tetraplegic patients  

Microsoft Academic Search

We studied the respiratory muscles with magnetic transcranial stimulation (TCS) in four spinal cord injured (SCI) patients as compared to age-matched controls from a database of 40 healthy subjects. These SCI patients all had spinal cord lesions above C6 level with a clinically incomplete tetraplegia. One patient was artificially ventilated. Motor evoked potentials (MEPs) were recorded from the diaphragm, the

Mark A Lissens; Guy G Vanderstraeten

1996-01-01

42

Nationwide surveillance of bacterial respiratory pathogens conducted by the Japanese Society of Chemotherapy in 2007: general view of the pathogens’ antibacterial susceptibility  

Microsoft Academic Search

For the purpose of a nationwide surveillance of the antimicrobial susceptibility of bacterial respiratory pathogens in patients\\u000a in Japan, the Japanese Society of Chemotherapy conducted their second year survey, during the period from January to August,\\u000a 2007. A total of 1178 strains were collected from clinical specimens obtained from adult patients with well-diagnosed respiratory\\u000a tract infections. Susceptibility testing was evaluable

Y. Niki; H. Hanaki; T. Matsumoto; M. Yagisawa; S. Kohno; N. Aoki; A. Watanabe; J. Sato; R. Hattori; M. Terada; N. Koashi; T. Kozuki; A. Maruo; K. Morita; K. Ogasawara; Y. Takahashi; J. Watanabe; K. Takeuchi; S. Fujimura; H. Takeda; H. Ikeda; N. Sato; K. Niitsuma; M. Saito; S. Koshiba; M. Kaneko; M. Miki; S. Nakanowatari; Y. Honda; J. Chiba; H. Takahashi; M. Utagawa; T. Kondo; A. Kawana; H. Konosaki; Y. Aoki; H. Ueda; H. Sugiura; M. Ichioka; H. Goto; D. Kurai; M. Okazaki; K. Yoshida; T. Yoshida; Y. Tanabe; S. Kobayashi; M. Okada; H. Tsukada; Y. Imai; Y. Honma; K. Nishikawa; T. Yamamoto; A. Kawai; T. Kashiwabara; Y. Takesue; Y. Wada; K. Nakajima; T. Miyara; H. Toda; N. Mitsuno; H. Sugimura; S. Yoshioka; M. Kurokawa; Y. Munekawa; H. Nakajima; S. Kubo; Y. Ohta; K. Mikasa; K. Maeda; K. Kasahara; A. Koizumi; R. Sano; S. Yagi; M. Takaya; Y. Kurokawa; N. Kusano; E. Mihara; M. Kuwabara; Y. Fujiue; T. Ishimaru; N. Matsubara; Y. Kawasaki; H. Tokuyasu; K. Masui; K. Negayama; N. Ueda; M. Ishimaru; Y. Nakanishi; M. Fujita; J. Honda; J. Kadota; K. Hiramatsu; Z. Nagasawa; M. Suga; H. Muranaka; K. Yanagihara; J. Fujita; M. Tateyama; K. Sunakawa; K. Totsuka

2009-01-01

43

Nationwide surveillance of bacterial respiratory pathogens conducted by the Japanese Society of Chemotherapy in 2008: general view of the pathogens’ antibacterial susceptibility  

Microsoft Academic Search

For the purpose of nationwide surveillance of the antimicrobial susceptibility of bacterial respiratory pathogens collected\\u000a from patients in Japan, the Japanese Society of Chemotherapy conducted a third year of nationwide surveillance during the\\u000a period from January to April 2008. A total of 1,097 strains were collected from clinical specimens obtained from well-diagnosed\\u000a adult patients with respiratory tract infections. Susceptibility testing

Yoshihito NikiHideaki; Hideaki Hanaki; Tetsuya Matsumoto; Morimasa Yagisawa; Shigeru Kohno; Nobuki Aoki; Akira Watanabe; Junko Sato; Rikizo Hattori; Naoto Koashi; Michinori Terada; Tsuneo Kozuki; Akinori Maruo; Kohei Morita; Kazuhiko Ogasawara; Yoshisaburo Takahashi; Kenji Matsuda; Kunio Nakanishi; Keisuke Sunakawa; Kenichi Takeuchi; Seiichi Fujimura; Hiroaki Takeda; Hideki Ikeda; Naohito Sato; Katsunao Niitsuma; Miwako Saito; Shizuko Koshiba; Michiyo Kaneko; Makoto Miki; Susumu Nakanowatari; Hiroshi Takahashi; Mutsuko Utagawa; Hajime Nishiya; Sayoko Kawakami; Yasuko Aoki; Naohiko Chonabayashi; Hideko Sugiura; Masahiko Ichioka; Hajime Goto; Daisuke Kurai; Takeshi Saraya; Mitsuhiro Okazaki; Koichiro Yoshida; Takashi Yoshida; Hiroki Tsukada; Yumiko Imai; Yasuo Honma; Toshinobu Yamamoto; Atsuro Kawai; Hiroshige Mikamo; Yoshio Takesue; Yasunao Wada; Takeyuki Miyara; Hirofumi Toda; Noriko Mitsuno; Yasunori Fujikawa; Hirokazu Nakajima; Shuichi Kubo; Yoshio Ohta; Keiichi Mikasa; Kei Kasahara; Akira Koizumi; Reiko Sano; Shinichi Yagi; Mariko Takaya; Yukinori Kurokawa; Nobuchika Kusano; Eiichiro Mihara; Motoko Nose; Masao Kuwabara; Yoshihiro Fujiue; Toshiyuki Ishimaru; Nobuo Matsubara; Yuji Kawasaki; Hirokazu Tokuyasu; Kayoko Masui; Masamitsu Kido; Toshiyuki Ota; Junichi Honda; Junichi Kadota; Kazufumi Hiramatsu; Yosuke Aoki; Zenzo Nagasawa; Katsunori Yanagihara; Jiro Fujita; Masao Tateyama; Kyoichi Totsuka

44

In vitro susceptibility of upper respiratory tract pathogens to 13 oral antimicrobial agents.  

PubMed

An in vitro comparison of the activities of 13 oral antimicrobial agents against clinical isolates of bacteria commonly responsible for causing upper respiratory tract infections was performed. With regard to Haemophilus influenzae, beta-lactamase-negative strains were susceptible to amoxycillin, augmentin, cefaclor, erythromycin, trimethoprim, cotrimoxazole and tetracycline, with CL 284,635 being the most active agent. With the exception of amoxycillin these drugs were also active against beta-lactamase-producing strains. CL 284,635 was also very active against Branhamella catarrhalis isolates, including beta-lactamase-producing strains, but was less active against the Gram-positive bacteria tested. Cefadroxil, cephradine and cephalexin were mainly active against Gram-positive pathogens. Based on minimum inhibitory concentration determinations, cefaclor, augmentin and co-trimoxazole would be appropriate drugs for the treatment of those cases of otitis media and sinusitis where H. influenzae and Streptococcus pneumoniae are important pathogens provided they are susceptible to these agents. PMID:3660122

Liebowitz, L D; Saunders, J; Koornhof, H J

1987-09-19

45

Unaltered respiratory-related evoked potentials after acute diaphragm dysfunction in humans  

Microsoft Academic Search

Respiratory muscles play an important role in the origin of respiratory sensations. Data dissecting the role of the diaphragm and other inspiratory muscles are scarce. This study aimed to determine the impact of diaphragm dysfunction following inspiratory resistive loading on respiratory-related evoked potentials considered as a neurophysiological substrate of certain types of respiratory sensations. Altogether, nine subjects aged 25-50 yrs

M. Bezzi; C. Donzel-Raynaud; C. Straus; C. Tantucciz; M. Zelter; J. P. Derenne; T. Similowski

2003-01-01

46

Biosynthesis of the respiratory toxin bongkrekic acid in the pathogenic bacterium Burkholderia gladioli.  

PubMed

Bongkrekic acid (BA), an infamous respiratory toxin of the pathogenic bacterium Burkholderia gladioli, causes lethal intoxications when tempe bongkrek is produced with contaminated Rhizopus oligosporus cultures. Genome sequencing of B. gladioli pathovar cocovenenans unveiled the genetic basis for BA biosynthesis, and pointed to a homologous bon gene cluster in a B. gladioli strain from an infected rice plant. For functional genetics in B. gladioli ? Red recombination was established. Dissection of the modular type I polyketide synthase (a trans-AT PKS) provided insights into complex polyketide assembly. Isoprenoid-like ?-branching events and a six-electron oxidation of a methyl group to a carboxylic acid give rise to the unique branched tricarboxylic fatty acid. The role of the cytochrome P450 monooxygenase, BonL, was proven by structural elucidation of deoxybongkrekic acid from a mutant. PMID:22999884

Moebius, Nadine; Ross, Claudia; Scherlach, Kirstin; Rohm, Barbara; Roth, Martin; Hertweck, Christian

2012-09-21

47

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

PubMed

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 interactions. Pathogen-free phytoseiid mites are important to obtain high efficacy in biological pest control and to get reliable data in mite research, as pathogens may affect the performance of their host or alter their reproduction and behaviour. Potential and verified pathogens have been reported for phytoseiid mites during the past 25 years. The present review provides an overview, including potential pathogens with unknown host effects (17 reports), endosymbiotic Wolbachia (seven reports), other bacteria (including Cardinium and Spiroplasma) (four reports), cases of unidentified diseases (three reports) and cases of verified pathogens (six reports). From the latter group four reports refer to Microsporidia, one to a fungus and one to a bacterium. Only five entities have been studied in detail, including Wolbachia infecting seven predatory mite species, other endosymbiotic bacteria infecting Metaseiulus (Galendromus, Typhlodromus) occidentalis (Nesbitt), the bacterium Acaricomes phytoseiuli infecting Phytoseiulus persimilis Athias-Henriot, the microsporidium Microsporidium phytoseiuli infecting P. persimilis and the microsporidium Oligosproridium occidentalis infecting M. occidentalis. In four cases (Wolbachia, A. phytoseiuli, M. phytoseiuli and O. occidentalis) an infection may be connected with fitness costs of the host. Moreover, infection is not always readily visible as no obvious gross symptoms are present. Monitoring of these entities on a routine and continuous basis should therefore get more attention, especially in commercial mass-production. Special attention should be paid to field-collected mites before introduction into the laboratory or mass rearing, and to mites that are exchanged among rearing facilities. However, at present general pathogen monitoring is not yet practical as effects of many entities are unknown. More research effort is needed concerning verified and potential pathogens of commercially reared arthropods and those used as model organisms in research. PMID:18763041

Schütte, Conny; Dicke, Marcel

2008-12-01

48

Are we ready for novel detection methods to treat respiratory pathogens in hospital-acquired pneumonia?  

PubMed

Hospital-acquired pneumonia represents one of the most difficult treatment challenges in infectious diseases. Many studies suggest that the timely administration of appropriate, pathogen-directed therapy can be lifesaving. Because results of culture and antimicrobial susceptibility testing can take 48 h or longer, physicians currently rely on clinical, epidemiological, and demographic factors to assist with the choice of empiric therapy for antibiotic-resistant pathogens. At present, a number of rapid molecular tests are being developed that identify pathogens and the presence of genetic determinants of antimicrobial resistance (eg, GeneXpert [Cepheid], ResPlex [Qiagen], FilmArray [Idaho Technologies], and Microarray [Check-Points]). In this review, the potential impact that molecular diagnostics has to identify and characterize pathogens that cause hospital-acquired bacterial pneumonia at an early stage is examined. In addition, a perspective on a novel technology, polymerase chain reaction followed by electrospray ionization mass spectrometry, is presented, and its prospective use in the diagnosis of pneumonia is also discussed. The complexities of the pulmonary microbiome represent a novel challenge to clinicians, but many questions still remain even as these technologies improve. PMID:21460299

Endimiani, Andrea; Hujer, Kristine M; Hujer, Andrea M; Kurz, Sebastian; Jacobs, Michael R; Perlin, David S; Bonomo, Robert A

2011-05-01

49

Are We Ready for Novel Detection Methods to Treat Respiratory Pathogens in Hospital-Acquired Pneumonia?  

PubMed Central

Hospital-acquired pneumonia represents one of the most difficult treatment challenges in infectious diseases. Many studies suggest that the timely administration of appropriate, pathogen-directed therapy can be lifesaving. Because results of culture and antimicrobial susceptibility testing can take 48 h or longer, physicians currently rely on clinical, epidemiological, and demographic factors to assist with the choice of empiric therapy for antibiotic-resistant pathogens. At present, a number of rapid molecular tests are being developed that identify pathogens and the presence of genetic determinants of antimicrobial resistance (eg, GeneXpert [Cepheid], ResPlex [Qiagen], FilmArray [Idaho Technologies], and Microarray [Check-Points]). In this review, the potential impact that molecular diagnostics has to identify and characterize pathogens that cause hospital-acquired bacterial pneumonia at an early stage is examined. In addition, a perspective on a novel technology, polymerase chain reaction followed by electrospray ionization mass spectrometry, is presented, and its prospective use in the diagnosis of pneumonia is also discussed. The complexities of the pulmonary microbiome represent a novel challenge to clinicians, but many questions still remain even as these technologies improve.

Endimiani, Andrea; Hujer, Kristine M.; Hujer, Andrea M.; Kurz, Sebastian; Jacobs, Michael R.; Perlin, David S.

2011-01-01

50

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.

2014-01-01

51

Antimicrobial susceptibility profiles among common respiratory tract pathogens: a GLOBAL perspective.  

PubMed

Antimicrobial resistance by common respiratory tract pathogens remains a global concern, but surveillance programs allow us to recognize trends in susceptibility that may help guide empiric antimicrobial selection. During 2003 to 2004, the Global Landscape On the Bactericidal Activity of Levofloxacin (GLOBAL) surveillance program collected 9323 isolates of Streptococcus pneumoniae, 5828 isolates of Haemophilus influenzae, and 1878 isolates of Moraxella catarrhalis from 15 countries worldwide, and tested them for susceptibility to commonly used antimicrobial agents at a central laboratory. For S pneumoniae, penicillin (oral) susceptibility ranged from 41.5% (Asia) to 75.3% (Europe), while susceptibility to erythromycin ranged from 23.7% (Asia) to 87.0% (Central and South America). Susceptibility to levofloxacin was > or = 98.0% for each region studied, with the minimum inhibitory concentration (90%) (MIC(90)) = 1 microg/mL. Susceptibility to ciprofloxacin was > or = 81% for each region studied, with the MIC(90) = 2 microg/mL. For H influenzae, resistance to ampicillin ranged from 8.7% (South Africa) to 29.6% (Asia), while resistance to trimethoprimsulfamethoxazole ranged from 15.3% (United States) to 40.3% (Asia). Moraxella catarrhalis isolates from each region were > 95.0% susceptible to all antimicrobials tested. Susceptibility of H influenzae and M catarrhalis to levofloxacin was > 99.0% in each country. In general, S pneumoniae resistance to penicillin and macrolides remains a concern. Although the prevalence of ss-lactamase production by H influenzae and M catarrhalis can be high, these organisms continue to be susceptible to several commonly used antimicrobials. Respiratory fluoroquinolones continue to show high activity against these 3 organisms. There has been no change in the levofloxacin MIC(90) values for S pneumoniae and only rarely have resistant isolates of H influenzae and M catarrhalis been identified worldwide. PMID:18931467

Sahm, Daniel F; Brown, Nina P; Thornsberry, Clyde; Jones, Mark E

2008-09-01

52

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.

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

2009-01-01

53

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

54

Rapid Identification and Strain-Typing of Respiratory Pathogens for Epidemic Surveillance.  

National Technical Information Service (NTIS)

Epidemic respiratory infections are responsible for extensive morbidity and mortality within both military and civilian populations. We describe a methodology to examine respiratory samples that simultaneously identifies broad groups of bacteria. The proc...

D. J. Ecker R. Sampath L. B. Blyn V. Samant K. Russell

2003-01-01

55

A multiplexed reverse transcriptase PCR assay for identification of viral respiratory pathogens at point-of-care  

SciTech Connect

We have developed a nucleic acid-based assay that is rapid, sensitive, specific, and can be used for the simultaneous detection of 5 common human respiratory pathogens including influenza A, influenza B, parainfluenza type 1 and 3, respiratory syncytial virus, and adenovirus group B, C, and E. Typically, diagnosis on an un-extracted clinical sample can be provided in less than 3 hours, including sample collection, preparation, and processing, as well as data analysis. Such a multiplexed panel would enable rapid broad-spectrum pathogen testing on nasal swabs, and therefore allow implementation of infection control measures, and timely administration of antiviral therapies. This article presents a summary of the assay performance in terms of sensitivity and specificity. Limits of detection are provided for each targeted respiratory pathogen, and result comparisons are performed on clinical samples, our goal being to compare the sensitivity and specificity of the multiplexed assay to the combination of immunofluorescence and shell vial culture currently implemented at the UCDMC hospital. Overall, the use of the multiplexed RT-PCR assay reduced the rate of false negatives by 4% and reduced the rate of false positives by up to 10%. The assay correctly identified 99.3% of the clinical negatives, 97% of adenovirus, 95% of RSV, 92% of influenza B, and 77% of influenza A without any extraction performed on the clinical samples. The data also showed that extraction will be needed for parainfluenza virus, which was only identified correctly 24% of the time on un-extracted samples.

Letant, S E; .Ortiz, J I; Tammero, L; Birch, J M; Derlet, R W; Cohen, S; Manning, D; McBride, M T

2007-04-11

56

Isolation, propagation, and characterization of a newly recognized pathogen, cilia-associated respiratory bacillus of rats, an etiological agent of chronic respiratory disease.  

PubMed Central

A Gram-negative, filamentous, rod-shaped bacillus which failed to grow in cell-free media was isolated in apparently pure culture from the bronchial scraping and washing of a laboratory rat suffering from chronic respiratory disease by inoculating embryonated chicken eggs via the allantoic route. None of the embryos died during 20 serial passages at weekly intervals. The bacillus was reisolated in embryonated eggs from cesarean-derived barrier-maintained N:SD(SD) rats 8 and 12 weeks after intranasal inoculation with 10th-passage allantoic fluid. The inoculated rats were housed in Horsfall-type units and remained free from other known respiratory pathogens, including mycoplasmas and murine viruses, throughout the study. The bacillus colonized the ciliated epithelial cells of the respiratory tract and caused a marked peribronchial infiltration and hyperplasia of mononuclear cells which progressed with time. The bacillus, ca. 0.2 micron wide by 4 to 6 micron long, stained very poorly with basic aniline dyes but was readily demonstrated with the Warthin-Starry silver technique. It was heat labile (56 degrees C for 30 min); spore forms were not observed. It withstood freeze-thawing and was successfully stored at -70 degrees C. Although no visible means of locomotion was observed with the electron microscope, a slow gliding motility, sometimes with bending and flexing of bacilli apparently adherent to the glass surface, was observed with phase microscopy. As an etiological agent of chronic respiratory disease of rats, this cilia-associated respiratory bacillus (tentatively designated the CAR bacillus) may be the first recognized gliding bacterium known to cause disease in a warm-blooded vertebrate. Images

Ganaway, J R; Spencer, T H; Moore, T D; Allen, A M

1985-01-01

57

Bioactive potential of Streptomyces against fish and shellfish pathogens  

PubMed Central

Background and Objectives In the present study, isolation of Streptomyces associated with marine sponges and its bioactive potential against fish and shellfish pathogens were assessed. The Streptomyces sp. were isolated from the marine sponges namely Callyspongia diffusa, Mycale mytilorum, Tedania anhelans and Dysidea fragilis collected from Vizhinjam port, situated in the South-West coast of India. Materials and Methods The Streptomyces associated with marine sponges were isolated using specific ISP media. The isolates of Streptomyces were characterized for their colony characteristics, morphological properties, physiological and biochemical properties and were tentatively identified. The strains were cultivated on a lab scale level as shake-flask cultures and the crude extracts of the bioactive compounds obtained with ethyl acetate were screened biologically and chemically. By biological screening, the extracts were analyzed for their activity against fish and shellfish pathogens namely Aeromonas hydrophila, Serratia sp. and Vibrio spp, using the disk and agar-well diffusion bioassay method, while by chemical screening the crude culture extracts were analyzed by TLC and UV–Vis spectrophotometer. Results Ninety-four isolates were found to be associated with marine sponges, among them only seven strains showed antagonism against fish and shellfish pathogens. Analysis of morphological, physiological and biochemical characteristics suggested that these strains belonged to the genus Streptomyces. The initial screening of the isolates by spot inoculation method exhibited antibacterial activity against Aeromonas hydrophila. In-vitro screening of the submerge culture extracts showed positive inhibition against the fish and shellfish pathogens namely Aeromonas hydrophila, Serratia sp. and Vibrio spp. The screening of bioactive compounds confirmed the production of polyene substances by UV spectrum, which resulted in absorbance peaks ranging from 225 to 245 nm and TLC analysis yielded Rf values ranging from 0.40 to 0.78. Conclusion The results suggest that the seven Streptomyces strains isolated from marine sponges produce potential antibacterial compounds against fish and shellfish pathogens.

Selvakumar, D; Arun, K; Suguna, S; Kumar, D; Dhevendaran, K

2010-01-01

58

Discovering Potential Pathogens among Fungi Identified as Nonsporulating Molds?  

PubMed Central

Fungal infections are increasing, particularly among immunocompromised hosts, and a rapid diagnosis is essential to initiate antifungal therapy. Often fungi cannot be identified by conventional methods and are classified as nonsporulating molds (NSM).We sequenced internal transcribed spacer regions from 50 cultures of NSM and found 16 potential pathogens that can be associated with clinical disease. In selected clinical settings, identification of NSM could prove valuable and have an immediate impact on patient management.

Pounder, June I.; Simmon, Keith E.; Barton, Claudia A.; Hohmann, Sheri L.; Brandt, Mary E.; Petti, Cathy A.

2007-01-01

59

Pathogenicity of severe acute respiratory coronavirus deletion mutants in hACE-2 transgenic mice.  

PubMed

Recombinant severe acute respiratory virus (SARS-CoV) variants lacking the group specific genes 6, 7a, 7b, 8a, 8b and 9b (rSARS-CoV-Delta[6-9b]), the structural gene E (rSARS-CoV-DeltaE), and a combination of both sets of genes (rSARS-CoV-Delta[E,6-9b]) have been generated. All these viruses were rescued in monkey (Vero E6) cells and were also infectious for human (Huh-7, Huh7.5.1 and CaCo-2) cell lines and for transgenic (Tg) mice expressing the SARS-CoV receptor human angiotensin converting enzyme-2 (hACE-2), indicating that none of these proteins is essential for the viral cycle. Furthermore, in Vero E6 cells, all the viruses showed the formation of particles with the same morphology as the wt virus, indicating that these proteins do not have a high impact in the final morphology of the virions. Nevertheless, in the absence of E protein, release of virus particles efficacy was reduced. Viruses lacking E protein grew about 100-fold lower than the wt virus in lungs of Tg infected mice but did not grow in the brains of the same animals, in contrast to the rSARS-CoV-Delta[6-9b] virus, which grew almost as well as the wt in both tissues. Viruses lacking E protein were highly attenuated in the highly sensitive hACE-2 Tg mice, in contrast to the minimal rSARS-CoV-Delta[6-9b] and wt viruses. These data indicate that E gene might be a virulence factor influencing replication level, tissue tropism and pathogenicity of SARS-CoV, suggesting that DeltaE attenuated viruses are promising vaccine candidates. PMID:18452964

Dediego, Marta L; Pewe, Lecia; Alvarez, Enrique; Rejas, Maria Teresa; Perlman, Stanley; Enjuanes, Luis

2008-07-01

60

Nasal colonization by four potential respiratory bacteria in healthy children attending kindergarten or elementary school in Seoul, Korea.  

PubMed

A longitudinal analysis was carried out of the colonization by four potential respiratory pathogens - Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Staphylococcus aureus - in 165 healthy children (aged 3-7 years) attending three kindergartens and 417 healthy children (aged 7-10 years) attending an elementary school in Seoul, Korea, by four consecutive examinations over 1 year. The prevalence of nasal carriers of one or more of four bacteria was found to be higher in younger children (?7 years) (mean 68.6%) than that in older children (mean 46.8%). The mean rates of nasal carriage of Strep. pneumoniae, H. influenzae, M. catarrhalis and Staph. aureus were 16.8, 18.9, 20.2 and 18.2%, respectively. Colonization by Strep. pneumoniae, H. influenzae and M. catarrhalis was higher in pre-school children (28.6, 32.4 and 35.0%, respectively) than in school children (12.2, 13.6 and 14.3%, respectively). Carriage trends differed with age, with Strep. pneumoniae, H. influenzae and M. catarrhalis colonization decreasing with age but Staph. aureus colonization increasing. Positive associations of co-occurrence between Strep. pneumoniae, H. influenzae and M. catarrhalis were evident, with a significant negative association evident between Staph. aureus and the other three bacteria. A better understanding of the colonization and interaction of potential respiratory pathogens may be important for predicting changes in bacterial ecology and for designing control strategies that target bacterial colonization in upper respiratory tract infections. PMID:22282460

Bae, Songmee; Yu, Jae-Yon; Lee, Kwangjun; Lee, Sunhwa; Park, Bohyun; Kang, Yeonho

2012-05-01

61

Upper respiratory tract microbial communities, acute otitis media pathogens, and antibiotic use in healthy and sick children.  

PubMed

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

Pettigrew, Melinda M; Laufer, Alison S; Gent, Janneane F; Kong, Yong; Fennie, Kristopher P; Metlay, Joshua P

2012-09-01

62

Orally administered Lactobacillus rhamnosus modulates the respiratory immune response triggered by the viral pathogen-associated molecular pattern poly(I:C)  

PubMed Central

Background Some studies have shown that probiotics, including Lactobacillus rhamnosus CRL1505, had the potential to beneficially modulate the outcome of certain bacterial and viral respiratory infections. However, these studies did not determine the mechanism(s) by which probiotics contribute to host defense against respiratory viruses. Results In this work we demonstrated that orally administered Lactobacillus rhamnosus CRL1505 (Lr1505) was able to increase the levels of IFN-?, IL-10 and IL-6 in the respiratory tract and the number of lung CD3+CD4+IFN-?+ T cells. To mimic the pro-inflammatory and physiopathological consecuences of RNA viral infections in the lung, we used an experimental model of lung inflammation based on the administration of the artificial viral pathogen-associated molecular pattern poly(I:C). Nasal administration of poly(I:C) to mice induced a marked impairment of lung function that was accompanied by the production of pro-inflammatory mediators and inflammatory cell recruitment into the airways. The preventive administration of Lr1505 reduced lung injuries and the production of TNF-?, IL-6, IL-8 and MCP-1 in the respiratory tract after the challenge with poly(I:C). Moreover, Lr1505 induced a significant increase in lung and serum IL-10. We also observed that Lr1505 was able to increase respiratory IFN-? levels and the number of lung CD3+CD4+IFN-?+ T cells after poly(I:C) challenge. Moreover, higher numbers of both CD103+ and CD11bhigh dendritic cells and increased expression of MHC-II, IL-12 and IFN-? in these cell populations were found in lungs of Lr1505-treated mice. Therefore, Lr1505 treatment would beneficially regulate the balance between pro-inflammatory mediators and IL-10, allowing an effective inflammatory response against infection and avoiding tissue damage. Conclusions Results showed that Lr1505 would induce a mobilization of cells from intestine and changes in cytokine profile that would be able to beneficially modulate the respiratory mucosal immunity. Although deeper studies are needed using challenges with respiratory viruses, the results in this study suggest that Lr1505, a potent inducer of antiviral cytokines, may be useful as a prophylactic agent to control respiratory virus infection.

2012-01-01

63

Rethinking Biosafety in Research on Potential Pandemic Pathogens  

PubMed Central

ABSTRACT If accidentally released, mammalian-transmissible influenza A/H5N1 viruses could pose a greater threat to public health than possibly any other infectious agent currently under study in laboratories, because of such viruses’ likely combination of transmissibility and virulence to humans. We advocate explicit risk-benefit assessments before work on such pathogens is permitted or funded, improvement of biosafety practices and enforcement, and harmonization of criteria for permitting such experiments across government agencies, as well as internationally. Such potential pandemic pathogens, as they have been called, jeopardize not only laboratory workers and their contacts, but also the wider population, who should be involved in assessments of when such risks are acceptable in the service of scientific knowledge that may itself bear major public health benefits.

Lipsitch, Marc; Bloom, Barry R.

2012-01-01

64

G-scores: A method for identifying disease-causing pathogens with application to lower respiratory tract infections.  

PubMed

Lower respiratory tract infections (LRTIs) are well known for the lack of a good diagnostic method. The main difficulty lies in the fact that there are a variety of pathogens causing LRTIs, and their management and treatment are quite different. The development of quantitative real-time loop-mediated isothermal amplification (qrt-LAMP) made it possible to rapidly amplify and quantify multiple pathogens simultaneously. The question that remains to be answered is how accurate and reliable is this method? More importantly, how are qrt-LAMP measurements utilized to inform/suggest medical decisions? When does a pathogen start to grow out of control and cause infection? Answers to these questions are crucial to advise treatment guidance for LRTIs and also helpful to design phase I/II trials or adaptive treatment strategies. In this article, our main contributions include the following two aspects. First, we utilize zero-inflated mixture models to provide statistical evidence for the validity of qrt-LAMP being used in detecting pathogens for LRTIs without the presence of a gold standard test. Our results on qrt-LAMP suggest that it provides reliable measurements on pathogens of interest. Second, we propose a novel statistical approach to identify disease-causing pathogens, that is, distinguish the pathogens that colonize without causing problems from those that rapidly grow and cause infection. We achieve this by combining information from absolute quantities of pathogens and their symbiosis information to form G-scores. Change-point detection methods are utilized on these G-scores to detect the three phases of bacterial growth-lag phase, log phase, and stationary phase. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24599506

Zhang, Peng; Peng, Peichao; Wang, Lu; Kang, Yu

2014-07-20

65

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.

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

66

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

67

Human serum activity of telithromycin, azithromycin and amoxicillin/clavulanate against common aerobic and anaerobic respiratory pathogens.  

PubMed

Telithromycin is a new ketolide antimicrobial with a good in vitro activity against both aerobic and anaerobic respiratory pathogens. In this study, we evaluated the antibacterial activity over time of telithromycin (800mg), azithromycin (500mg), and amoxicillin/clavulanate (875/125mg) in serum following single oral doses of these agents to 10 healthy subjects. Inhibitory and bactericidal titers were determined at 2, 6, 12, and 24h after each dose and the median titer was used to determine antibacterial activity. Against two azithromycin-resistant strains of Streptococcus pneumoniae, both telithromycin (MIC=0.25 and 0.5 microg/mL) and amoxicillin/clavulanate exhibited inhibitory and cidal activity for at least 6h. All three antibiotics provided prolonged (>or=12h) inhibitory activity against strains of Hemophilus influenzae (telithromycin MIC=4.0 microg/ml). Both telithromycin and amoxicillin/clavulanate exhibited rapid and prolonged inhibitory activity (>or=12h) against each of the anaerobes studied (Finegoldia [Peptostreptococcus] magna Peptostreptococcus micros, Prevotella bivia, and Prevotella melaninogenica). Moreover, both agents provided bactericidal activity against both Prevotella species. In this ex vivo pharmacodynamic study, we found that telithromycin provided rapid and prolonged antibacterial activity in serum against macrolide-resistant strains of S. pneumoniae, beta-lactamase-positive and -negative strains of H. influenzae, and common respiratory anaerobic pathogens. These findings suggest that telithromycin could have clinical utility in the treatment of community-acquired mixed aerobic-anaerobic respiratory tract infections, including chronic sinusitis and aspiration pneumonia. PMID:17189093

Stein, Gary E; Schooley, Sharon; Tyrrell, Kerin L; Citron, Diane M; Goldstein, Ellie J C

2007-01-01

68

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

Microsoft Academic Search

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

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

2005-01-01

69

Tracking resistance among bacterial respiratory tract pathogens: summary of findings of the TRUST Surveillance Initiative, 2001-2005.  

PubMed

Antimicrobial resistance observed among common respiratory tract pathogens--Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis--may complicate empiric therapeutic selection to treat community-acquired respiratory tract infections. The Tracking Resistance in the United States Today (TRUST) study determined the in vitro activities of frequently prescribed antimicrobial agents against isolates collected from all 50 states from 2001 to 2005. For S pneumoniae (N = 27,781), susceptibility of selected agents in ascending order were penicillin (oral) (65.4%), trimethoprim-sulfamethoxazole (TMP-SMX) (69.5%), erythromycin (72.0%), cefuroxime (oral) (75.9%), tetracycline (85.3%), amoxicillinclavulanate (92.6%), ceftriaxone (nonmeningitis) (96.6%), and levofloxacin (99.0%). Susceptibility to levofloxacin, which was used as a representative of the respiratory fluoroquinolones, was near 99% from 2001 to 2005, and the minimum inhibitory concentration (90%) (MIC(90)) remained unchanged at 1 microg/mL. Levofloxacin and the other respiratory fluoroquinolones remained highly effective against penicillin-resistant S pneumoniae(PRSP) (98%-99% susceptible). However, susceptibility of PRSP to amoxicillin-clavulanate decreased from 62%S in 2003 to 48%S in 2005. Haemophilus influenzae susceptibility to ampicillin averaged near 70%, and near 75% to TMP-SMX. Susceptibility rates to levofloxacin and the other respiratory fluoroquinolones for H influenzae and M catarrhalis remained at or near 100%. Although resistance rates among S pneumoniae have stabilized for penicillin (oral) at elevated levels and increased for macrolides, susceptibility to the respiratory fluoroquinolones has consistently remained high, as they have for H influenzae and M catarrhalis. PMID:18931466

Sahm, Daniel F; Brown, Nina P; Draghi, Deborah C; Evangelista, Alan T; Yee, Y Cheung; Thornsberry, Clyde

2008-09-01

70

Laboratory investigations on the low pathogenic potential of Plesiomonas shigelloides.  

PubMed Central

The pathogenic properties of 16 Plesiomonas shigelloides strains recovered from humans with extraintestinal and intestinal illnesses, infected animals, and environmental sources were investigated. Most strains possessed a high cell charge and low surface hydrophobicity analogous to those of Shigella spp.; additionally, serogroup O:17 strains reacted with Shigella group D antisera. However, unlike the shigellae, P. shigelloides strains did not universally bind Congo red, were noninvasive in HEp-2 cell assays, and did not produce a Shiga-like toxin on Vero cells. On HEp-2, Y1, and possibly Vero cells, a low-level cytolysin was consistently produced by all 16 P. shigelloides strains when grown in either Evan Casamino Acids-yeast extract or Penassay broth. The median 50% lethal dose for all 16 P. shigelloides strains in outbred Swiss Webster mice was 3.5 x 10(8) CFU (range, 3.2 x 10(7) to greater than 1 x 10(9) CFU). Animal pathogenicity did not correlate with cytolysin expression, possession of a greater than or equal to 120-MDa plasmid, protein profile, or resistance to complement-mediated lysis. No strain analyzed produced siderophores or a heat-stable enterotoxin. The results suggest that members of the genus Plesiomonas have an overall low pathogenic potential, irrespective of the site of isolation or phenotypic, serologic, or surface properties shared with other traditional enteropathogens. Images

Abbott, S L; Kokka, R P; Janda, J M

1991-01-01

71

Microbial diversity and potential pathogens in ornamental fish aquarium water.  

PubMed

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

72

Quantifying the potential pathogens transmission of the blowflies (Diptera: Calliphoridae).  

PubMed

To quantify the potential capability of transporting and passing infective pathogens of some blowflies (Diptera: Calliphoridae), Mihályi's danger-index was calculated for seven species. The original equation was modified to include synanthropic information to discriminate between asynanthropic, hemisynanthropic, and eusynanthropic status. Three groups were recognized, of which Phaenicia cluvia and Musca domestica proved the flies with lowest index value (D = 2.93 and 3.00 respectively); Cochliomyia macellaria, Chrysomya albiceps and Sarconesia chlorogaster presented a significantly higher index value (p<0.10; D = 4.28, 4.44 and 5.66 respectively) and C. megacephala, C. vicina and P. sericata appear to represent the heaviest potential sanitary risk with the highest index value (p<0.10; D = 15.54, 16.88 and 12.49 respectively). PMID:12764436

Maldonado, Marcelo A; Centeno, Néstor

2003-03-01

73

[Activity of tigecycline against pathogen bacteria isolated in respiratory infectious disease in Europe. TEST study 2004-2007].  

PubMed

Tigecycline (TGC), a semisynthetic glycylcycline, has a documented activity on Gram+ and Gram- pathogens including oxacillin-resistant (MRSA) and an extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae. Tigecycline Evaluation and Surveillance Trial (TEST) is an international surveillance study designed to assess the in vitro activity of TGC and 11 comparators against a range of important clinical pathogens from both the community and the hospital. The aim of this study was to assess efficacy of TGC, using this database, against pathogens implicated in community or hospital pneumonia and sinusitis. A total of 4163 isolates were consecutively collected in 21 European countries during three years (2004-2007). In all center, minimum inhibitory concentration (MIC) were determinated with the same Microscan panel (Dade-Behring). Tigecycline exhibited a good activity against respiratory pathogens, with the exception of Pseudomonas aeruginosa. Hundred percent of cocci Gram+ (Streptococcus pneumoniae, Staphylococcus aureus, Enterococcus sp.) and 100% of Haemophilus sp. are inhibited with 0.5 mg/L, without effect of an associated beta-lactam resistance mechanism. TGC is active in vitro on 89% of Enterobacteriaceae, with MIC 90 less or equal to 2mg/L. Eighty-nine percent of Enterobacter sp. and 77% of Serratia sp. are susceptible with range of MIC 90 from 2 to 4 mg/L. These interesting results obtained in vitro are to be strengthened by clinical studies. PMID:18829182

Rio, Y; Okamba, P; Staal, A; Didion, J; Jurin, F

2009-02-01

74

The respiratory syncytial virus fusion protein and neutrophils mediate the airway mucin response to pathogenic respiratory syncytial virus infection.  

PubMed

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; Moore, Martin L

2013-09-01

75

Collagen VI Is a Subepithelial Adhesive Target for Human Respiratory Tract Pathogens  

Microsoft Academic Search

Bacterial engagement of specific host tissue structures can be a means of targeting a pathogen to a particular niche, establishing persistent infections and inducing invasion. In this context, primary adhesion is often the first crucial colonization step allowing pathogens to withstand the mechanical clearing mechanisms of the host. As a consequence, bacteria have evolved adhesins with the capacity to mediate

Marta Bober; Charlotte Enochsson; Mattias Collin; Matthias Mörgelin

2010-01-01

76

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.

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

2012-01-01

77

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...

78

Mediterranean Fruit Fly as a Potential Vector of Bacterial Pathogens  

PubMed Central

The Mediterranean fruit fly (Ceratitis capitata) is a cosmopolitan pest of hundreds of species of commercial and wild fruits. It is considered a major economic pest of commercial fruits in the world. Adult Mediterranean fruit flies feed on all sorts of protein sources, including animal excreta, in order to develop eggs. After reaching sexual maturity and copulating, female flies lay eggs in fruit by puncturing the skin with their ovipositors and injecting batches of eggs into the wounds. In view of the increase in food-borne illnesses associated with consumption of fresh produce and unpasteurized fruit juices, we investigated the potential of Mediterranean fruit fly to serve as a vector for transmission of human pathogens to fruits. Addition of green fluorescent protein (GFP)-tagged Escherichia coli to a Mediterranean fruit fly feeding solution resulted in a dose-dependent increase in the fly's bacterial load. Flies exposed to fecal material enriched with GFP-tagged E. coli were similarly contaminated and were capable of transmitting E. coli to intact apples in a cage model system. Washing contaminated apples with tap water did not eliminate the E. coli. Flies inoculated with E. coli harbored the bacteria for up to 7 days following contamination. Fluorescence microscopy demonstrated that the majority of fluorescent bacteria were confined along the pseudotrachea in the labelum edge of the fly proboscis. Wild flies captured at various geographic locations were found to carry coliforms, and in some cases presumptive identification of E. coli was made. These findings support the hypothesis that the common Mediterranean fruit fly is a potential vector of human pathogens to fruits.

Sela, Shlomo; Nestel, David; Pinto, Riky; Nemny-Lavy, Esther; Bar-Joseph, Moshe

2005-01-01

79

[Distribution of potential pathogenic bacteria in the Jiulong River Watershed].  

PubMed

Recently, the human activities including economic growth and urbanization posed serious environmental health risks to the Jiulong River Watershed (JRW). In order to gain a full understanding of the distribution of potential pathogenic bacteria (PPB) in this area, we used 16S rRNA amplicon pyrosequencing technology to investigate planktonic and benthic bacterial community in two main tributaries (North River, NR, and West River, WR) of the Jiulong River (JR). At the genus level, a total of 68 genera of PPB were identified in JR, which accounted for 6. 1% of total gene sequences. Clostridium, Mycobacterium and Sphingomonas were three most dominant genera, which accounted for 54. 5% , 5.9% and 5. 6% of the total gene sequences respectively, and occurred in all samples. At the species level, a total of 48 species of PPB were identified in JR, which accounted for 0.76% of total gene sequences. Afipia felis, Mycobacterium asiaticum, Clostridium baratii, Brucella melitensis and Delftia tsuruhatensis were the five most dominant species, and accounted for 48.9% , 20.3% , 8% , 2.7% and 1.7% , respectively. Statistical analysis indicated that the number of taxa (species or genera) of PPB in JR water samples were significantly more than those from JR sediment samples. Moreover, WR water samples harbored the most abundant and diverse of PPB, suggesting that WR water might have a high potential risk for pathogen contamination. In addition, statistical analysis indicated that the diversity and abundance of PPB (species or genera) are significantly positively correlated with nutrient (nitrogen and phosphorus) concentrations, suggesting that human activities in the JRW such as sewage discharge from livestock and wastewater treatment facilities play important roles on affecting the distribution of PPB in JR. Therefore, in order to protect the public health, more efforts are needed to prevent water contamination, and conduct the real-time monitoring of PPB in JR. PMID:25055661

Hou, Li-Yuan; Hu, An-Yi; Ma, Ying; Yu, Chang-Ping

2014-05-01

80

Viral Pathogens and Severe Acute Respiratory Syndrome: Oligodynamic Ag1 for Direct Immune Intervention  

Microsoft Academic Search

This retrospective study of silver-based therapeutics briefly reviews their history, and then explores the modern application of charged silver particles, especially as an antiviral agent. The recent outbreak of severe acute respiratory syndrome (SARS) suggests this is timely. Medical literature shows that a variety of viruses have been successfully treated with silver- based drugs. However, 'silver salts' and\\/or inferior silver

ERIC J. RENTZ

81

Activities of New Fluoroquinolones against Fluoroquinolone- Resistant Pathogens of the Lower Respiratory Tract  

Microsoft Academic Search

The activities of six new fluoroquinolones (moxifloxacin, grepafloxacin, gatifloxacin, trovafloxacin, clinaflox- acin, and levofloxacin) compared with those of sparfloxacin and ciprofloxacin with or without reserpine (20 mg\\/ ml) were determined for 19 Streptococcus pneumoniae isolates, 5 Haemophilus sp. isolates, and 10 Pseudomonas aeruginosa isolates with decreased susceptibility to ciprofloxacin from patients with clinically confirmed lower respiratory tract infections. Based upon

LAURA J. V. PIDDOCK; M. JOHNSON; V. RICCI; S. L. HILL

1998-01-01

82

Common oligosaccharide moieties inhibit the adherence of typical and atypical respiratory pathogens  

Microsoft Academic Search

Intervention in bacterial adhesion to host cells is a novel method of overcoming current problems associated with antibiotic resistance. Antibiotic-resistant strains of bacteria that cause respiratory tract infections are a problem in hospitals and could be used in bioterrorist attacks. A range of bacterial species was demonstrated to attach to an alveolar epithelial (A549) cell line. In all cases, cell

Richard Thomas; Tim Brooks

2004-01-01

83

In vitro Activity of Sparfloxacin Compared with Ciprofloxacin and Ofloxacin against Respiratory Tract Pathogens  

Microsoft Academic Search

The in vitro activity of sparfloxacin, a new fluoroquinolone, was compared with ciprofloxacin and ofloxacin against 166 consecutive isolates from the upper respiratory tract of outpatients. The strains were fully susceptible to three quinolones. The antibacterial activity of sparfloxacin was comparable or better than that of ofloxacin and ciprofloxacin against all strains. Sparfloxacin was fourfold more active against Staphylococcus aureus

A.-S. Malmborg; S. Ahlén

1993-01-01

84

Rates of antimicrobial resistance among common bacterial pathogens causing respiratory, blood, urine, and skin and soft tissue infections in pediatric patients  

Microsoft Academic Search

Antimicrobial resistance patterns among the principal bacterial pathogens from infections of the respiratory tract, blood, skin and soft tissue, and urinary tract of pediatric patients from the USA, Canada, Germany, France, and Italy were studied using the The Surveillance Network (TSN) database. Among Streptococcus pneumoniae isolates from respiratory tract infections, the prevalence of high-level penicillin resistance (MIC=2 µg\\/ml) ranged from 1.1

M. E. Jones; J. A. Karlowsky; D. C. Draghi; C. Thornsberry; D. F. Sahm; J. S. Bradley

2004-01-01

85

Enterohepatic Helicobacter in Ulcerative Colitis: Potential Pathogenic Entities?  

PubMed Central

Background Changes in bacterial populations termed “dysbiosis” are thought central to ulcerative colitis (UC) pathogenesis. In particular, the possibility that novel Helicobacter organisms play a role in human UC has been debated but not comprehensively investigated. The aim of this study was to develop a molecular approach to investigate the presence of Helicobacter organisms in adults with and without UC. Methodology/Principal Findings A dual molecular approach to detect Helicobacter was developed. Oligonucleotide probes against the genus Helicobacter were designed and optimised alongside a validation of published H. pylori probes. A comprehensive evaluation of Helicobacter genus and H. pylori PCR primers was also undertaken. The combined approach was then assessed in a range of gastrointestinal samples prior to assessment of a UC cohort. Archival colonic samples were available from 106 individuals for FISH analysis (57 with UC and 49 non-IBD controls). A further 118 individuals were collected prospectively for dual FISH and PCR analysis (86 UC and 32 non-IBD controls). An additional 27 non-IBD controls were available for PCR analysis. All Helicobacter PCR-positive samples were sequenced. The association between Helicobacter and each study group was statistically analysed using the Pearson Chi Squared 2 tailed test. Helicobacter genus PCR positivity was significantly higher in UC than controls (32 of 77 versus 11 of 59, p?=?0.004). Sequence analysis indicated enterohepatic Helicobacter species prevalence was significantly higher in the UC group compared to the control group (30 of 77 versus 2 of 59, p<0.0001). PCR and FISH results were concordant in 74 (67.9%) of subjects. The majority of discordant results were attributable to a higher positivity rate with FISH than PCR. Conclusions/Significance Helicobacter organisms warrant consideration as potential pathogenic entities in UC. Isolation of these organisms from colonic tissue is needed to enable interrogation of pathogenicity against established criteria.

Thomson, John M.; Hansen, Richard; Berry, Susan H.; Hope, Mairi E.; Murray, Graeme I.; Mukhopadhya, Indrani; McLean, Mairi H.; Shen, Zeli; Fox, James G.; El-Omar, Emad; Hold, Georgina L.

2011-01-01

86

Molecular characterization of transcriptome-wide interactions between highly pathogenic porcine reproductive and respiratory syndrome virus and porcine alveolar macrophages in vivo.  

PubMed

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

87

Exploiting the potential of insects for in vivo pathogenicity testing of microbial pathogens  

Microsoft Academic Search

Conventional assays for quantifying the virulence of microbial pathogens and mutants have traditionally relied upon the use of a range of mammalian species. A number of workers have demonstrated that insects can be used for evaluating microbial pathogenicity and provide results comparable to those that can be obtained with mammals since one component of the vertebrate immune system, the innate

Kevin Kavanagh; Emer P. Reeves

2004-01-01

88

Isolation of antibiotic-resistant pathogenic and potentially pathogenic bacteria from carpets of mosques in Tripoli, Libya  

PubMed Central

Objective Isolation of potentially pathogenic bacteria from carpets in hospitals has been reported earlier, but not from carpets in mosques. The aim of the present study is to determine the pathogenic and potentially pathogenic bacteria that may exist on the carpets of mosques in Tripoli, Libya. Methods Dust samples from carpets were collected from 57 mosques in Tripoli. Samples were examined for pathogenic bacteria using standard bacteriological procedures. Susceptibility of isolated bacteria to antimicrobial agents was determined by the disc-diffusion method. Results Of dust samples examined, Salmonella spp. was detected in two samples (3.5%, 1 in group B and 1 in group C1), Escherichia coli in 16 samples (28.1%), Aeromonas spp. in one sample (1.8%), and Staphylococcus aureus in 12 samples (21.1%). Multiple drug resistance was observed in >16.7% of E. coli and in 25% of S. aureus. Conclusion Contamination of carpets in mosques of Tripoli with antibiotic-resistant pathogenic and potentially pathogenic bacteria may pose a health risk to worshipers, particularly, the very young, the old and the immunecompromised. Worshipers are encouraged to use personal praying mats when praying in mosques.

Rahouma, Amal; Elghamoudi, Abdunabi; Nashnoush, Halima; Belhaj, Khalifa; Tawil, Khaled; Sifaw Ghenghesh, Khalifa

2010-01-01

89

Demonstration of the metaphylactic use of gamithromycin against bacterial pathogens associated with bovine respiratory disease in a multicentre farm trial.  

PubMed

On five commercial cattle rearing sites across Europe, a total of 802 young cattle at high risk of developing bovine respiratory disease (BRD) associated with the bacterial pathogens Mannheimia haemolytica or Pasteurella multocida and/or Mycoplasma bovis were enrolled into a multicentre, controlled field trial. Half were treated with a single dose of gamithromycin at 6 mg/kg bodyweight by subcutaneous injection and half received an injection of a saline placebo as the control. All animals were observed daily for 14 days for signs of BRD as defined by set criteria. The proportion of metaphylactic preventive treatment successes, defined as animals surviving to day 14 without signs of BRD, in the gamithromycin-treated group (86 per cent) was significantly (P=0.0012) higher than in the saline-treated controls (61 per cent). Morbidity among the treated animals was reduced by 64 per cent compared with the controls. PMID:21493573

Baggott, D; Casartelli, A; Fraisse, F; Manavella, C; Marteau, R; Rehbein, S; Wiedemann, M; Yoon, S

2011-03-01

90

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

91

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.

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

92

LOW PATHOGENIC POTENTIAL IN HETEROTROPHIC BACTERIA FROM POTABLE WATER  

EPA Science Inventory

Forty-five isolates of HPC bacteria, most of which express virulence-related characteristics are being tested for pathogenicity in immunocompromised mice. All forty-five were negative for facultative intracellular pathogenicity. All twenty-three isolates tested thus far were a...

93

Monoclonal antibodies against Nsp2 protein of the highly pathogenic porcine reproductive and respiratory syndrome virus.  

PubMed

Porcine reproductive and respiratory syndrome (PRRS) continues to be a serious threat, causing an economically significant impact on the swine industry worldwide. In this study, non-structural protein Nsp2 of porcine reproductive and respiratory syndrome virus (PRRSV) was expressed in Escherichia coli and purified by dialysis. An important monoclonal antibody (MAb 2H6) against Nsp2 protein was generated by fusing mouse myeloma cell line SP2/0 with spleen lymphocytes from Nsp2 protein immunized mice. Then activity of the MAb was characterized by enzyme-linked immunosorbent assay (ELISA), Western blot analysis, and indirect immunofluorescence assays. The results demonstrated that the MAb has a positive reaction to HP-PRRSV in IFA at 1:100 dilution and in Western blot analysis at 1:500 dilution, and no reaction with classic PRRSV. These indicated that this MAb against Nsp2 protein of PRRSV might be a good candidate for a specific diagnostic method and functional exploration of the Nsp2 protein. PMID:24111869

Li, Bin; Du, Luping; Sun, Bing; Yu, Zhengyu; Wen, Libin; Zhang, Xuehan; Guo, Rongli; Ni, Yanxiu; Hu, Yiyi; Zhou, Junming; Zhu, Haodan; Lv, Lixin; Yu, Yang; Wang, Xiaomin; He, Kongwang

2013-10-01

94

Pharmacokinetics of cefuroxime axetil and cefaclor: relationship of concentrations in serum to MICs for common respiratory pathogens.  

PubMed Central

The pharmacokinetics of single doses of cefaclor at 250 and 375 mg and cefuroxime axetil at 250 mg administered under optimal conditions (i.e., cefuroxime axetil after food and cefaclor in the fasted state) were studied in 24 healthy male volunteers. Drug concentrations in serum were related to MICs for common respiratory tract pathogens by using data generated from a recently completed national survey. The time the concentrations in serum exceeded the MICs for Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella (formerly Branhamella) catarrhalis were significantly greater (P less than 0.05) for cefuroxime axetil at 250 mg than for cefaclor at 250 or 375 mg. With the recommended dosing regimens (cefuroxime axetil at 250 mg and cefaclor at 375 mg twice daily or cefaclor at 250 mg three times daily), cefuroxime concentrations exceed the MIC for 90% of the strains tested for a greater time period than cefaclor concentrations with either regimen. The reasons for this difference are (i) the greater potency and slower clearance of cefuroxime compared with those of cefaclor and (ii) the greater sensitivity of these pathogens to cefuroxime.

James, N C; Donn, K H; Collins, J J; Davis, I M; Lloyd, T L; Hart, R W; Powell, J R

1991-01-01

95

Targeting the mitochondrial respiratory chain of Cryptococcus through antifungal chemosensitization: a model for control of non-fermentative pathogens.  

PubMed

Enhanced control of species of Cryptococcus, non-fermentative yeast pathogens, was achieved by chemosensitization through co-application of certain compounds with a conventional antimicrobial drug. The species of Cryptococcus tested showed higher sensitivity to mitochondrial respiratory chain (MRC) inhibition compared to species of Candida. This higher sensitivity results from the inability of Cryptococcus to generate cellular energy through fermentation. To heighten disruption of cellular MRC, octyl gallate (OG) or 2,3-dihydroxybenzaldehyde (2,3-DHBA), phenolic compounds inhibiting mitochondrial functions, were selected as chemosensitizers to pyraclostrobin (PCS; an inhibitor of complex III of MRC). The cryptococci were more susceptible to the chemosensitization (i.e., PCS + OG or 2,3-DHBA) than the Candida with all Cryptococcus strains tested being sensitive to this chemosensitization. Alternatively, only few of the Candida strains showed sensitivity. OG possessed higher chemosensitizing potency than 2,3-DHBA, where the concentration of OG required with the drug to achieve chemosensitizing synergism was much lower than that required of 2,3-DHBA. Bioassays with gene deletion mutants of the model yeast Saccharomyces cerevisiae showed that OG or 2,3-DHBA affect different cellular targets. These assays revealed mitochondrial superoxide dismutase or glutathione homeostasis plays a relatively greater role in fungal tolerance to 2,3-DHBA or OG, respectively. These findings show that application of chemosensitizing compounds that augment MRC debilitation is a promising strategy to antifungal control against yeast pathogens. PMID:23892633

Kim, Jong H; Haff, Ronald P; Faria, Natália C G; Martins, Maria de L; Chan, Kathleen L; Campbell, Bruce C

2013-01-01

96

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.

2011-01-01

97

Development of a New Resequencing Pathogen Microarray Based Assay for Detection of Broad-Spectrum Respiratory Tract Viruses in Patients with Community-Acquired Pneumonia  

PubMed Central

A Resequencing Pathogen Microarray (RPM) is a single, highly multiplexed assay for detecting and differentiating similarly related pathogens by using closely overlapping probe sets to determine a target organism’s nucleotide sequence. In this study, a new RPM (RPM-IVDC1) that consisted of 224-bp detector tiles corresponding to 9 influenza A subtypes, 11 rhinoviruses, 28 enteroviruses and 38 other respiratory viruses was developed and optimized to provide individual and simultaneous detection sensitivities ranging from 15 to 750 genomic copies for 16 common respiratory pathogens. A total of 110 consecutive patients with community-acquired pneumonia (CAP) admitted to 5 district general hospitals in Beijing during a 1-year period were assessed using the new assay. Among the children (under age 5) and adult patients (above age 18), respiratory syncytial virus (RSV) and rhinovirus (RV) were the most common etiological agents, respectively, which is consistent with reference assays. Atypical pathogens that may cause CAP-like illness, including rubella virus, measles virus, influenza type C virus, human herpesvirus (HHV) were also detected. The results show the capability of RPM-IVDC1 for the accurate detection and identification of multiple virus types, which may be of significant use in epidemic surveillance and outbreak investigations of atypical pathogens.

Wang, Miao; Li, Jin; Zhang, Chen; Nie, Kai; Yang, Mengjie; Zhang, Yi; Li, Aihua; Tan, Wenjie; Ma, Xuejun

2013-01-01

98

Social contacts of school children and the transmission of respiratory-spread pathogens.  

PubMed

Empirical data about contact frequencies of children is needed for estimating parameters in mathematical modelling studies that investigate the effect of targeting influenza intervention to children. A survey about the social contacts of school children was conducted in a primary school in Germany. The distribution of the daily numbers of contacts was stratified by age of the contacted person and by weekday. A negative binomial regression analysis was performed to investigate factors that influence contact behaviour. Using logistic regression analysis we examined the relationship between the numbers of private contacts and having been ill in the last 6 months. We computed effective contact numbers to take the heterogeneity in contact behaviour into account in assessing the contribution of children's contacts to the overall transmission of an infection. The possible effects of intervention measures such as school closure and vaccination on the transmission of respiratory-spread agents to other age groups are discussed. PMID:17634160

Mikolajczyk, R T; Akmatov, M K; Rastin, S; Kretzschmar, M

2008-06-01

99

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.

Monteoliva, Lucia; Querol, Amparo; Molina, Maria; Fernandez-Espinar, Maria T.

2014-01-01

100

[Recent development in animal testing to predict the skin and respiratory sensitizing potential of chemicals].  

PubMed

The identification of chemicals with skin and/or respiratory sensitizing potential is important for the prevention of allergic diseases in both living and work environments. Although a number of animal models for respiratory allergic diseases have been reported, none of these models meets the goals of broad assessments of chemical sensitizing potential. We are attempting to develop a test for predicting the respiratory sensitization of chemicals. In the evaluation of skin sensitization of chemicals, the mostly used predictive tests are the guinea pig maximization test, Buehler test, and mouse local lymph node assay (LLNA). However, only LLNA has been validated formally and independently. Recent studies have revealed that EC3 estimated by LLNA correlates well with human skin sensitizing potency and the threshold for the induction of skin sensitization in the human repeat patch test. Thus, LLNA can predict the potency of skin sensitizing potential of a chemical and its risk in humans. PMID:20134104

Aoyama, Kohji

2010-01-01

101

*Biomarkers of acute respiratory allergen exposure: Screening for sensitization potential  

EPA Science Inventory

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 fol...

102

Respiratory infections during air travel.  

PubMed

An increasing number of individuals undertake air travel annually. Issues regarding cabin air quality and the potential risks of transmission of respiratory infections during flight have been investigated and debated previously, but, with the advent of severe acute respiratory syndrome and influenza outbreaks, these issues have recently taken on heightened importance. Anecdotally, many people complain of respiratory symptoms following air travel. However, studies of ventilation systems and patient outcomes indicate the spread of pathogens during flight occurs rarely. In the present review, aspects of the aircraft cabin environment that affect the likelihood of transmission of respiratory pathogens on airplanes are outlined briefly and evidence for the occurrence of outbreaks of respiratory illness among airline passengers are reviewed. PMID:15667469

Leder, K; Newman, D

2005-01-01

103

The complete genome sequence of the murine respiratory pathogen Mycoplasma pulmonis  

PubMed Central

Mycoplasma pulmonis is a wall-less eubacterium belonging to the Mollicutes (trivial name, mycoplasmas) and responsible for murine respiratory diseases. The genome of strain UAB CTIP is composed of a single circular 963 879 bp chromosome with a G + C content of 26.6 mol%, i.e. the lowest reported among bacteria, Ureaplasma urealyticum apart. This genome contains 782 putative coding sequences (CDSs) covering 91.4% of its length and a function could be assigned to 486 CDSs whilst 92 matched the gene sequences of hypothetical proteins, leaving 204 CDSs without significant database match. The genome contains a single set of rRNA genes and only 29 tRNAs genes. The replication origin oriC was localized by sequence analysis and by using the G + C skew method. Sequence polymorphisms within stretches of repeated nucleotides generate phase-variable protein antigens whilst a recombinase gene is likely to catalyse the site-specific DNA inversions in major M.pulmonis surface antigens. Furthermore, a hemolysin, secreted nucleases and a glyco-protease are predicted virulence factors. Surprisingly, several of the genes previously reported to be essential for a self-replicating minimal cell are missing in the M.pulmonis genome although this one is larger than the other mycoplasma genomes fully sequenced until now.

Chambaud, Isabelle; Heilig, Roland; Ferris, Stephane; Barbe, Valerie; Samson, Delphine; Galisson, Frederique; Moszer, Ivan; Dybvig, Kevin; Wroblewski, Henri; Viari, Alain; P.C. Rocha, Eduardo; Blanchard, Alain

2001-01-01

104

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.

2013-01-01

105

Mechanisms, molecular and sero-epidemiology of antimicrobial resistance in bacterial respiratory pathogens isolated from Japanese children  

PubMed Central

Background The clinical management of community-acquired respiratory tract infections (RTIs) is complicated by the increasing worldwide prevalence of antibacterial resistance, in particular, ?-lactam and macrolide resistance, among the most common causative bacterial pathogens. This study aimed to determine the mechanisms and molecular- and sero-epidemiology of antibacterial resistance among the key paediatric respiratory pathogens in Japan. Methods Isolates were collected at 18 centres in Japan during 2002 and 2003 from children with RTIs as part of the PROTEKT surveillance programme. A proportion of Haemophilus influenzae isolates was subjected to sequencing analysis of the ftsI gene; phylogenetic relatedness was assessed using multilocus sequence typing. Streptococcus pneumoniae isolates were screened for macrolide-resistance genotype by polymerase chain reaction and serotyped using the capsular swelling method. Susceptibility of isolates to selected antibacterials was performed using CLSI methodology. Results and Discussion Of the 557 H. influenzae isolates collected, 30 (5.4%) were ?-lactamase-positive [BL+], 115 (20.6%) were BL-nonproducing ampicillin-resistant (BLNAR; MIC ? 4 mg/L) and 79 (14.2%) were BL-nonproducing ampicillin-intermediate (BLNAI; MIC 2 mg/L). Dabernat Group III penicillin binding protein 3 (PBP3) amino acid substitutions in the ftsI gene were closely correlated with BLNAR status but phylogenetic analysis indicated marked clonal diversity. PBP mutations were also found among BL+ and BL-nonproducing ampicillin-sensitive isolates. Of the antibacterials tested, azithromycin and telithromycin were the most active against H. influenzae (100% and 99.3% susceptibility, respectively). A large proportion (75.2%) of the 468 S. pneumoniae isolates exhibited macrolide resistance (erythromycin MIC ? 1 mg/L); erm(B) was the most common macrolide resistance genotype (58.8%), followed by mef(A) (37.2%). The most common pneumococcal serotypes were 6B (19.7%), 19F (13.7%), 23F (13.5%) and 6A (12.8%). Telithromycin and amoxicillin-clavulanate were the most active antibacterials against S. pneumoniae (99.8% and 99.6% susceptibility, respectively). Conclusion Approximately one-third of H. influenzae isolates from paediatric patients in Japan are BLNAI/BLNAR, mainly as a result of clonally diverse PBP3 mutations. Together with the continued high prevalence of pneumococcal macrolide resistance, these results may have implications for the clinical management of paediatric RTIs in Japan.

Sunakawa, Keisuke; Farrell, David J

2007-01-01

106

Clinical and bacteriological efficacy of the ketolide telithromycin against isolates of key respiratory pathogens: a pooled analysis of phase III studies.  

PubMed

A pooled analysis of data from 13 phase III studies of telithromycin in the treatment of community-acquired pneumonia, acute exacerbations of chronic bronchitis, acute sinusitis or group A beta-haemolytic streptococcal pharyngitis and tonsillitis was undertaken. Causative key respiratory tract pathogens (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus and Streptococcus pyogenes) were isolated at entry to the studies from cultures of relevant respiratory samples and tested for their susceptibility to telithromycin, penicillin and macrolides (erythromycin A). The combined clinical and bacteriological efficacy of telithromycin at the post-therapy, test-of-cure visit (days 17-24) was assessed in patients from whom a microbiologically evaluable pathogen was isolated at entry. More than 98% of key respiratory pathogens isolated, including penicillin G- and macrolide (erythromycin A)-resistant strains of S. pneumoniae, demonstrated full or intermediate susceptibility to telithromycin in vitro at the breakpoints of < or = 1.0 mg/L (susceptible) and 2.0 mg/L (intermediate) used for the purpose of evaluating the susceptibility of isolates recovered during the clinical trials. Treatment with telithromycin 800 mg once-daily for 5, 7 or 7-10 days resulted in high rates of clinical cure (88.5%) and a satisfactory bacteriological outcome (88.9%), similar to the figures seen with comparator antibacterial agents. Clinical cure and eradication rates were good for all key respiratory pathogens, including penicillin G- and macrolide (erythromycin A)-resistant S. pneumoniae. The results suggest that telithromycin will provide effective empirical therapy for community-acquired upper and lower respiratory tract infections. PMID:14706083

Low, D E; Brown, S; Felmingham, D

2004-01-01

107

Distribution of potential nosocomial pathogens in a hospital environment  

Microsoft Academic Search

The distribution of probable nosocomial pathogens in a government hospital in Nigeria was investigated. Thirty swab and air samples were collected from patients, hospital personnel, formites and air in four wards namely orthopaedic (OW), paediatric (PW), surgical (SW) and medical (MW). For the patients and personnel, skin and nasal samples were taken. A total of 56 Gram positive (45) and

C. B. Chikere; V. T. Omoni; B. O. Chikere

2008-01-01

108

Computational analysis and identification of an emergent human adenovirus pathogen implicated in a respiratory fatality  

PubMed Central

Adenoviral infections are typically acute, self-limiting, and not associated with death. However, we present the genomic and bioinformatics analysis of a novel recombinant human adenovirus (HAdV-D56) isolated in France that caused a rare neonatal fatality, and keratoconjunctivitis in three health care workers who cared for the neonate. Whole genome alignments revealed the expected diversity in the penton base, hexon, E3, and fiber coding regions, and provided evidence for extensive recombination. Bootscan analysis confirmed recombination between HAdV-D9, HAdV-D26, HAdV-D15, and HAdV-D29 in the penton base and hexon proteins, centered around hypervariable loops within the putative proteins. Protein structure analysis of the fiber coding region revealed similarity with HAdV-D8, HAdV-D9, and HAdV-D53, possibly accounting for the ocular tropism of the virus. Based on these data, this virus appears to be a new HAdV-D type (HAdV-D56), underscoring the importance of recombination events in human adenovirus evolution and the emergence of new adenovirus pathogens.

Robinson, Christopher M.; Singh, Gurdeep; Henquell, Cecile; Walsh, Michael P.; Peigue-Lafeuille, Helene; Seto, Donald; Jones, Morris S.; Dyer, David W.; Chodosh, James

2010-01-01

109

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.

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

2011-01-01

110

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.

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

2009-01-01

111

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...

112

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...

113

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...

114

Chest Radiograph Scores as Potential Prognostic Indicators in Severe Acute Respiratory Syndrome (SARS)  

Microsoft Academic Search

OBJECTIVE. We analyzed serial chest radiographic scores for lung opacification in pa- tients with severe acute respiratory syndrome (SARS) for temporal changes and differences be- tween fatal and discharged cases. We sought to establish the earliest radiographic scores sensitive as potential prognostic indicators of fatal outcomes. MATERIALS AND METHODS. Chest radiographs that had been obtained from pre- sentation until the

Gregory E. Antonio; Ka T. Wong; Eva L. H. Tsui; David P. N. Chan; David S. C. Hui; Alex W. H. Ng; Kwok K. Shing; Edmund H. Y. Yuen; Jane C. K. Chan; Anil T. Ahuja

115

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

PubMed

The pathogenesis of Type 2 highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) in 10-week old swine in the United States was investigated. rJXwn06, rescued from an infectious clone of Chinese HP-PRRSV, replicated in swine with at least 100-fold increased kinetics over U.S. strain VR-2332. rJXwn06 caused significant weight loss, exacerbated disease due to bacterial sepsis and more severe histopathological lung lesions in pigs exposed to HP-PRRSV than to those infected with VR-2332. Novel findings include identification of bacterial species present, the degree of thymic atrophy seen, and the inclusion of contact animals that highlighted the ability of HP-PRRSV to rapidly transmit between animals. Furthermore, comprehensive detailed cytokine analysis of serum, bronchoalveolar lavage fluid, and tracheobronchial lymph node tissue homogenate revealed a striking elevation in levels of cytokines associated with both innate and adaptive immunity in HP-PRRSV infected swine, and showed that contact swine differed in the degree of cytokine response. PMID:23079105

Guo, Baoqing; Lager, Kelly M; Henningson, Jamie N; Miller, Laura C; Schlink, Sarah N; Kappes, Matthew A; Kehrli, Marcus E; Brockmeier, Susan L; Nicholson, Tracy L; Yang, Han-Chun; Faaberg, Kay S

2013-01-20

116

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

117

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

118

Potentially durable resistance mechanisms in plants to specialised fungal pathogens  

Microsoft Academic Search

Specialised plant pathogens are in many ways adapted to exploit their host plants. Infective propagules should reach the appropriate\\u000a plant tissue, gain access to the tissue and negate or suppress various kinds of constitutive and inducible resistance mechanisms.\\u000a The resistance type most frequently deployed in plant breeding is the race-specific resistance, where a hypersensitive response\\u000a of plant tissue is elicited

Rients E. Niks; Diego Rubiales

2002-01-01

119

Biocontrol potential of Trichoderma species against mango malformation pathogens  

Microsoft Academic Search

Malformation disease of Mango (Mangifera indica L.) caused by Fusarium moniliforme var. subglutinans is one of the most destructive diseases, which is a major production constraint in the mango-growing regions of India. In this study, The bioagents Trichoderma viride (Tr1), Trichoderma virens (Tr2) and Trichoderma harzianum (Tr3) were evaluated in culture with the pathogens to monitor the antagonistic effect and

Pradeep Kumar; Ashok Kumar Misra; Dinesh Raj Modi; Vijai Kumar Gupta

2012-01-01

120

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.

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

2014-01-01

121

Bioengineered 2'-fucosyllactose and 3-fucosyllactose inhibit the adhesion of Pseudomonas aeruginosa and enteric pathogens to human intestinal and respiratory cell lines.  

PubMed

Human milk oligosaccharides help to prevent infectious diseases in breastfed infants. Larger scale testing, particularly in animal models and human clinical studies, is still limited due to shortened availability of more complex oligosaccharides. The purpose of this study was to evaluate 2'-fucosyllactose (2'-FL) and 3-fucosyllactose (3-FL) synthesized by whole-cell biocatalysis for their biological activity in vitro. Therefore, we have tested these oligosaccharides for their inhibitory potential of pathogen adhesion in two different human epithelial cell lines. 2'-FL could inhibit adhesion of Campylobacter jejuni, enteropathogenic Escherichia coli, Salmonella enterica serovar fyris, and Pseudomonas aeruginosa to the intestinal human cell line Caco-2 (reduction of 26%, 18%, 12%, and 17%, respectively), as could be shown for 3-FL (enteropathogenic E coli 29%, P aeruginosa 26%). Furthermore, adherence of P aeruginosa to the human respiratory epithelial cell line A549 was significantly inhibited by 2'-FL and 3-FL (reduction of 24% and 23%, respectively). These results confirm the biological and functional activity of biotechnologically synthesized human milk oligosaccharides. Mass-tailored human milk oligosaccharides could be used in the future to supplement infant formula ingredients or as preventatives to reduce the impact of infectious diseases. PMID:24074741

Weichert, Stefan; Jennewein, Stefan; Hüfner, Eric; Weiss, Christel; Borkowski, Julia; Putze, Johannes; Schroten, Horst

2013-10-01

122

Genetic Relationships between Respiratory Pathogens Isolated from Dental Plaque and Bronchoalveolar Lavage Fluid from Patients in the Intensive Care Unit Undergoing Mechanical Ventilation  

PubMed Central

Background Ventilator-associated pneumonia (VAP) is a leading cause of morbidity and mortality in patients hospitalized in intensive care units. Recent studies suggest that dental plaque biofilms serve as a reservoir for respiratory pathogens. The goal of this study was to determine the genetic relationship between strains of respiratory pathogens first isolated from the oral cavity and later isolated from bronchoalveolar lavage fluid from the same patient undergoing mechanical ventilation with suspected VAP. Methods Plaque and tracheal secretion samples were obtained on the day of hospital admission and every other day thereafter until discharge from the intensive care unit from 100 patients who underwent mechanical ventilation. Bronchoalveolar lavage was performed for 30 patients with suspected VAP. Pulse-field gel electrophoresis and multilocus sequence typing were used to determine the genetic relatedness of strains obtained from oral, tracheal, and bronchoalveolar lavage samples. Results Isolates of Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter species, and enteric species recovered from plaque from most patients were indistinguishable from isolates recovered from bronchoalveolar lavage fluid (i.e., had >95% similarity of pulse-field gel electrophoresis patterns). Nearly one-half of the Pseudomonas strains showed identical genetic profiles between patients, which suggested a common environmental source of infection. Conclusions Respiratory pathogens isolated from the lung are often genetically indistinguishable from strains of the same species isolated from the oral cavity in patients who receive mechanical ventilation who are admitted to the hospital from the community. Thus, dental plaque serves as an important reservoir for respiratory pathogens in patients who undergo mechanical ventilation. Trial registration ClinicalTrials.gov identifier: NCT00123123

Heo, Seok-Mo; Haase, Elaine M.; Lesse, Alan J.; Gill, Steven R.; Scannapieco, Frank A.

2013-01-01

123

PROTEKT 1999–2000: a multicentre study of the antibiotic susceptibility of respiratory tract pathogens in Hong Kong, Japan and South Korea  

Microsoft Academic Search

A multicentre surveillance study performed in the Far East during 1999–2000 investigated the in vitro activity of >20 antibacterials against common respiratory pathogens. In Hong Kong, Japan, and South Korea, 57.1, 44.5 and 71.5% Streptococcus pneumoniae were penicillin-resistant and 71.4, 77.9 and 87.6% were erythromycin-resistant, respectively. Overall, >90% of penicillin-resistant strains were also macrolide-resistant. All strains were susceptible to telithromycin.

Matsuhisa Inoue; Nam Yong Lee; Seto Wing Hong; Kyungwon Lee; David Felmingham

2004-01-01

124

Giant viruses of amoebae as potential human pathogens.  

PubMed

Giant viruses infecting phagocytic protists are composed of mimiviruses, the record holders of particle and genome size amongst viruses, and marseilleviruses. Since the discovery in 2003 at our laboratory of the first of these giant viruses, the Mimivirus, a growing body of data has revealed that they are common inhabitants of our biosphere. Moreover, from the outset, the story of Mimivirus has been linked to that of patients exhibiting pneumonia and it was shown that patients developed antibodies to this amoebal pathogen. Since then, there have been several proven cases of human infection or colonization with giant viruses of amoebae, which are known to host several bacteria that are human pathogens. Mimiviruses and marseilleviruses represent a major challenge in human pathology, as virological procedures implemented to date have not used appropriate media to allow their culture, and molecular techniques have used filtration steps that likely prevented their detection. Nevertheless, there is an increasing body of evidence that mimiviruses might cause pneumonia and that humans carry marseilleviruses, and re-analyses of metagenomic databases have provided evidence that these giant viruses can be common in human samples. The proportion of human infections related to these giant mimiviruses and marseilleviruses and the precise short- and long-term consequences of these infections have been scarcely investigated so far and should be the subject of future works. PMID:24157884

Colson, Philippe; La Scola, Bernard; Raoult, Didier

2013-01-01

125

Potential pathogens carried by Spanish ibex (Capra pyrenaica hispanica) in southern Spain.  

PubMed

The Spanish ibex (Capra pyrenaica hispanica) population of southern Spain was surveyed for potential pathogens associated with the conjunctiva, external ear canal, as well as reproductive and upper respiratory tracts. We sampled 321 ibex (131 adult males, 100 adult females, and 90 yearlings); these included 271 apparently healthy animals and 50 that were naturally infected with Sarcoptes scabiei. A total of 688 bacterial isolates were identified (377 gram-negatives, 225 gram-positives, and 86 Mycoplasma spp.); sex, age, location, infection with S. scabiei, and disposition of the animal (free-ranging versus captive) were evaluated as risk factors for infection. Infections with Mycoplasma agalactiae and Mycoplasma arginini were associated with age, having a higher frequency of isolation in young animals. With Escherichia coli, Mannheimia haemolytica, Pasteurella multocida biotype A, and Staphylococcus aureus, significantly higher isolation rates were associated with adults. The isolation frequency for E. coli was higher in females, whereas Moraxella bovis isolations were mostly associated with males. The presence of mange increased the risk of infection with both Streptococcus equi subsp. zooepidemicus and M. haemolytica. The geographic origin of sampled animals was related to the isolation of Branhamella ovis, M. agalactiae, and all Pasteurella sp. Isolations of M. haemolytica, P. multocida biotype A, E. coli, and B. ovis were more prevalent in samples from free-ranging rather than captive animals. Of the gram-positive bacteria, S. aureus represented the predominant species isolated from nasal, vaginal, and ocular samples. Mycoplasma agalactiae and M. arginini were the predominant Mycoplasma spp., and both were associated most often with the external ear canal. The most frequently isolated gram-negative bacteria included E. coli, M. haemolytica, P. multocida biotype A, and B. ovis. Isolation rates of gram-negative species varied by source. In nasal samples, M. haemolytica and P. multocida biotype A were isolated most frequently, whereas in ocular and vaginal samples, B. ovis and E. coli, respectively, were most frequently isolated. PMID:16870855

González-Candela, Mónica; Cubero-Pablo, María José; Martín-Atance, Pablo; León-Vizcaíno, Luis

2006-04-01

126

Development of Indirect ELISAs for Differential Serodiagnosis of Classical and Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus.  

PubMed

The objective of this study was to develop two indirect enzyme-linked immunosorbent assays (iELISAs) for detection of serum antibodies against classical vaccine strain of porcine reproductive and respiratory syndrome virus (PRRSV) and highly pathogenic PRRSV (HP-PRRSV). To detect the common antibodies against classical and HP-PRRSV, the coating antigen used in the iELISA (designated iELISA-180) was the antigen of Nsp2-180, the 180aa at amino terminal of Nsp2. To detect the different antibodies against classical and HP-PRRSV, the coating antigen in the second iELISA (designated iELISA-D29) was Nsp2-D29, the deleted 29aa in Nsp2 of HP-PRRSV. The antigen concentration and serum dilutions were optimized using a draughtboard titration. The cut-off values of 0.361 at OD450nm for the iELISA-180 and 0.27 at OD450nm for the iELISA-D29 were determined by testing a panel of 120 classical PRRSV positive and 198 PRRSV negative pig serum samples, which generated the specificity of 97.1% and 96.7%, the sensitivity of 96.9% and 96.3% for iELISA-180 and iELISA-D29, respectively. The agreements between the Western blot and iELISA-180 and iELISA-D29 were 98%, 96.7%, respectively. The developed iELISAs can be used to differentiate serologically HP-PRRSV from the vaccinated or classical PRRSV in clinical serum samples. PMID:23217174

Xiao, Y H; Wang, T T; Zhao, Q; Wang, C B; Lv, J H; Nie, L; Gao, J M; Ma, X C; Hsu, W H; Zhou, E M

2014-08-01

127

Prediction and validation of potential pathogenic microRNAs involved in Phytophthora infestans infection.  

PubMed

Being one kind of approximately 22nt long small RNA, miRNA has shown its roles in host-pathogen interaction, providing one possible way for pathogen infection. Though Phytophthora infestans is a major pathogen that causes devastating late blight of potato, tomato and so on, so far there have not been any systematic researches on miRNAs and even pathogenic miRNAs in P. infestans. Here, for the first time we comprehensively predicted and identified pathogenic miRNAs that may exist in P. infestans. First, a total of 128 putative miRNAs belonging to 66 miRNA family were identified by bioinformatic approaches. Then, 33 vital pathogenic miRNAs were screened by constructing miRNA-miRNA relationship networks. Finally, four potential pathogenic miRNAs were chosen for detection, two of which are chosen for validation. The expression quantity of pi-miR466 and pi-miR1918 changed dramatically during incubation of tomato leaves, implying that they are potential pathogenic miRNAs. PMID:24430294

Cui, Juanjuan; Luan, Yushi; Wang, Weichen; Zhai, Junmiao

2014-03-01

128

The impact of animal age, bacterial coinfection, and isolate pathogenicity on the shedding of Porcine reproductive and respiratory syndrome virus in aerosols from experimentally infected pigs  

PubMed Central

The objective of this study was to evaluate the role of different variables (animal age, bacterial coinfection, and isolate pathogenicity) on the shedding of Porcine reproductive and respiratory syndrome virus (PRRSV) in aerosols. Animals were grouped according to age (2 versus 6 mo) and inoculated with a PRRSV isolate of either low (MN-30100) or high (MN-184) pathogenicity. Selected animals in each group were also inoculated with Mycoplasma hyopneumoniae. The pigs were anesthetized and aerosol samples (1000 breaths/sample) collected on alternating days from 1 to 21 after PRRSV inoculation. The results indicated that animal age (P = 0.09), M. hyopneumoniae coinfection (P = 0.09), and PRRSV isolate pathogenicity (P = 0.15) did not significantly influence the concentration of PRRSV in aerosols. However, inoculation with the PRRSV MN-184 isolate significantly increased the probability of aerosol shedding (P = 0.00005; odds ratio = 3.22). Therefore, the shedding of PRRSV in aerosols may be isolate-dependent.

Cho, Jenny G.; Dee, Scott A.; Deen, John; Trincado, Carlos; Fano, Eduardo; Jiang, Yin; Faaberg, Kay; Murtaugh, Michael P.; Guedes, Alonso; Collins, James E.; Joo, Han Soo

2006-01-01

129

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

130

Potential Human Pathogenic Bacteria in a Mixed Urban Watershed as Revealed by Pyrosequencing  

PubMed Central

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.

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

2013-01-01

131

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

132

Correlation of gross tumor volume excursion with potential benefits of respiratory gating  

SciTech Connect

Purpose: To test the hypothesis that the magnitude of thoracic tumor motion can be used to determine the desirability of respiratory gating. Methods and materials: Twenty patients to be treated for lung tumors had computed tomography image data sets acquired under assisted breath hold at normal inspiration (100% tidal volume), at full expiration (0% tidal volume), and under free breathing. A radiation oncologist outlined gross tumor volumes (GTVs) on the breath-hold computed tomographic images. These data sets were registered to the free-breathing image data set. Two sets of treatment plans were generated: one based on an internal target volume explicitly formed from assessment of the excursion of the clinical target volume (CTV) through the respiratory cycle, representing an ungated treatment, and the other based on the 0% tidal volume CTV, representing a gated treatment with little margin for residual motion. Dose-volume statistics were correlated to the magnitude of the motion of the center of the GTV during respiration. Results: Patients whose GTVs were >100 cm{sup 3} showed little decrease in lung dose under gating. The other patients showed a correlation between the excursion of the center of the GTV and a reduction in potential lung toxicity. As residual motion increased, the benefits of respiratory gating increased. Conclusion: Gating seems to be advantageous for patients whose GTVs are <100 cm{sup 3} and for whom the center of the GTV exhibits significant motion, provided residual motion under gating is kept small.

Starkschall, George [Department of Radiation Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)]. E-mail: gstarksc@mdanderson.org; Forster, Kenneth M. [Department of Radiation Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Kitamura, Kei [Department of Radiation Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Department of Radiology, Hokkaido University, Graduate School of Medicine, Sapporo (Japan); Cardenas, Alex [Department of Radiation Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Tucker, Susan L. [Department of Biomathematics, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Stevens, Craig W. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)

2004-11-15

133

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

134

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.

Locarnini, Stephen

2012-01-01

135

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

136

Comparison of the Luminex xTAG Respiratory Viral Panel with In-House Nucleic Acid Amplification Tests for Diagnosis of Respiratory Virus Infections  

Microsoft Academic Search

Detection of respiratory viruses using sensitive real-time nucleic acid amplification tests (NATs) is invalu- able for patient and outbreak management. However, the wide range of potential respiratory virus pathogens makes testing using individual real-time NATs expensive and laborious. The objective of this study was to compare the detection of respiratory virus targets using the Luminex xTAG respiratory viral panel (RVP)

Kanti Pabbaraju; Kara L. Tokaryk; Sallene Wong; Julie D. Fox

2008-01-01

137

Diagnosis of tuberculosis by trained African giant pouched rats and confounding impact of pathogens and microflora of the respiratory tract.  

PubMed

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; Kaufmann, Stefan H E

2012-02-01

138

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.

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

2012-01-01

139

Potential for the International Spread of Middle East Respiratory Syndrome in Association with Mass Gatherings in Saudi Arabia  

PubMed Central

Background: A novel coronavirus (MERS-CoV) causing severe, life-threatening respiratory disease has emerged in the Middle East at a time when two international mass gatherings in Saudi Arabia are imminent. While MERS-CoV has already spread to and within other countries, these mass gatherings could further amplify and/or accelerate its international dissemination, especially since the origins and geographic source of the virus remain poorly understood. Methods: We analyzed 2012 worldwide flight itinerary data and historic Hajj pilgrim data to predict population movements out of Saudi Arabia and the broader Middle East to help cities and countries assess their potential for MERS-CoV importation. We compared the magnitude of travel to countries with their World Bank economic status and per capita healthcare expenditures as surrogate markers of their capacity for timely detection of imported MERS-CoV and their ability to mount an effective public health response. Results: 16.8 million travelers flew on commercial flights out of Saudi Arabia, Jordan, Qatar, and the United Arab Emirates between June and November 2012, of which 51.6% were destined for India (16.3%), Egypt (10.4%), Pakistan (7.8%), the United Kingdom (4.3%), Kuwait (3.6%), Bangladesh (3.1%), Iran (3.1%) and Bahrain (2.9%). Among the 1.74 million foreign pilgrims who performed the Hajj last year, an estimated 65.1% originated from low and lower-middle income countries. Conclusion: MERS-CoV is an emerging pathogen with pandemic potential with its apparent epicenter in Saudi Arabia, where millions of pilgrims will imminently congregate for two international mass gatherings. Understanding global population movements out of the Middle East through the end of this year's Hajj could help direct anticipatory MERS-CoV surveillance and public health preparedness to mitigate its potential global health and economic impacts.

Khan, Kamran; Sears, Jennifer; Hu, Vivian Wei; Brownstein, John S; Hay, Simon; Kossowsky, David; Eckhardt, Rose; Chim, Tina; Berry, Isha; Bogoch, Isaac; Cetron, Martin

2013-01-01

140

Intranasal Immunization with an Archaeal Lipid Mucosal Vaccine Adjuvant and Delivery Formulation Protects against a Respiratory Pathogen Challenge  

PubMed Central

Archaeal lipid mucosal vaccine adjuvant and delivery (AMVAD) is a safe mucosal adjuvant that elicits long lasting and memory boostable mucosal and systemic immune responses to model antigens such as ovalbumin. In this study, we evaluated the potential of the AMVAD system for eliciting protective immunity against mucosal bacterial infections, using a mouse model of intranasal Francisella tularensis LVS (LVS) challenge. Intranasal immunization of mice with cell free extract of LVS (LVSCE) adjuvanted with the AMVAD system (LVSCE/AMVAD) induced F. tularensis-specific antibody responses in sera and bronchoalveolar lavage fluids, as well as antigen-specific splenocyte proliferation and IL-17 production. More importantly, the AMVAD vaccine partially protected the mice against a lethal intranasal challenge with LVS. Compared to LVSCE immunized and naïve mice, the LVSCE/AMVAD immunized mice showed substantial to significant reduction in pathogen burdens in the lungs and spleens, reduced serum and pulmonary levels of proinflammatory cytokines/chemokines, and longer mean time to death as well as significantly higher survival rates (p<0.05). These results suggest that the AMVAD system is a promising mucosal adjuvant and vaccine delivery technology, and should be explored further for its applications in combating mucosal infectious diseases.

Patel, Girishchandra B.; Zhou, Hongyan; Ponce, Amalia; Harris, Greg; Chen, Wangxue

2010-01-01

141

Potentiation of pathogen-specific defense mechanisms in Arabidopsis by beta -aminobutyric acid.  

PubMed

The nonprotein amino acids gamma-aminobutyric acid (GABA) and beta-aminobutyric acid (BABA) have known biological effects in animals and plants. Their mode of action has been the object of thorough research in animals but remains unclear in plants. Our objective was to study the mode of action of BABA in the protection of Arabidopis plants against virulent pathogens. BABA protected Arabidopsis against the oomycete pathogen Peronospora parasitica through activation of natural defense mechanisms of the plant such as callose deposition, the hypersensitive response, and the formation of trailing necroses. BABA was still fully protective against P. parasitica in transgenic plants or mutants impaired in the salicylic acid, jasmonic acid, and ethylene signaling pathways. Treatment with BABA did not induce the accumulation of mRNA of the systemic acquired resistance (SAR)-associated PR-1 and the ethylene- and jasmonic acid-dependent PDF1.2 genes. However, BABA potentiated the accumulation of PR-1 mRNA after attack by virulent pathogenic bacteria. As a result, BABA-treated Arabidopsis plants were less diseased compared with the untreated control. In the case of bacteria, BABA protected mutants insensitive to jasmonic acid and ethylene but was not active in plants impaired in the SAR transduction pathway. Thus, BABA protects Arabidopsis against different virulent pathogens by potentiating pathogen-specific plant resistance mechanisms. In addition, we provide evidence that BABA-mediated papilla formation after P. parasitica infection is independent of the SAR signaling pathway. PMID:11058166

Zimmerli, L; Jakab, G; Metraux, J P; Mauch-Mani, B

2000-11-01

142

Highly Pathogenic Avian Influenza Virus H7N7 Isolated From a Fatal Human Case Causes Respiratory Disease in Cats but Does Not Spread Systemically  

PubMed Central

Highly pathogenic avian influenza viruses (HPAIV) of the H5 and H7 subtypes primarily infect poultry but are occasionally transmitted to humans and other mammalian species, often causing severe disease. Previously we have shown that HPAIV H5N1 causes severe systemic disease in cats. In this study, we investigated whether HPAIV H7N7 isolated from a fatal human case is also able to cause disease in cats. Additionally, we compared the cell tropism of both viruses by immunohistochemistry and virus histochemistry. Three domestic cats were inoculated intratracheally with HPAIV H7N7. Virus excretion was restricted to the pharynx. At necropsy, 7 days post inoculation, lesions were restricted to the respiratory tract in all cats. Lesions consisted of diffuse alveolar damage and colocalized with virus antigen expression in type II pneumocytes and nonciliated bronchiolar cells. The attachment patterns of HPAIV H7N7 and H5N1 were similar: both viruses attached to nonciliated bronchiolar epithelial cells, type II pneumocytes, as well as alveolar macrophages. These data show for the first time that a non-H5 HPAIV is able to infect and cause respiratory disease in cats. The failure of HPAIV H7N7 to spread beyond the respiratory tract was not explained by differences in cell tropism compared to HPAIV H5N1. These findings suggest that HPAIV H5N1 possesses other characteristics that allow it to cause systemic disease in both humans and cats.

van Riel, Debby; Rimmelzwaan, Guus F.; van Amerongen, Geert; Osterhaus, Albert D.M.E.; Kuiken, Thijs

2010-01-01

143

Antimicrobial Activity of Home Disinfectants and Natural Products Against Potential Human Pathogens  

Microsoft Academic Search

OBJECTIVE: To assess the efficacy of both natural prod- ucts (vinegar, baking soda) and common commercial disinfectants (Vesphene IIse, TBQ, Clorox, Lysol Disinfectant Spray, Lysol Antibacterial Kitchen Cleaner, Mr. Clean Ultra, ethanol) designed for home or institutional use against potential human pathogens, including selected antibiotic-resistant bacteria. DESIGN: A quantitative suspension test was used to assess the efficacy of selected disinfectants

William A. Rutala; Susan L. Barbee; Newman C. Aguiar; Mark D. Sobsey; David J. Weber

2000-01-01

144

Potential Human Health Effects Associated with Pathogens in Urban Wet Weather Flows  

Microsoft Academic Search

High concentrations of pathogens and indicator organisms found in urban receiving waters are a common cause of concern. Though some question the actual public health risk associated with exposure to these organisms, large amounts of resources are spent attempting to identify and correct their source. This paper contains a summary of recent work describing the potential human health effects associated

Robert Pitt; Melinda Lalor; John Easton

145

Isolation of potentially pathogenic Escherichia coli O157:H7 from the Ganges River.  

PubMed

Escherichia coli serotype O157:H7 was detected among bacteria collected from the Ganges River. O157:H7 isolates tested positive for stx(1), stx(2), and eae gene sequences. Identification of potentially pathogenic isolates from extensively used source water indicates that O157:H7 may be a significant but as yet underacknowledged public health concern in India. PMID:17293524

Hamner, Steve; Broadaway, Susan C; Mishra, Veer Bhadra; Tripathi, Anshuman; Mishra, Rajesh Kumar; Pulcini, Elinor; Pyle, Barry H; Ford, Timothy E

2007-04-01

146

Isolation of Potentially Pathogenic Escherichia coli O157:H7 from the Ganges River?  

PubMed Central

Escherichia coli serotype O157:H7 was detected among bacteria collected from the Ganges River. O157:H7 isolates tested positive for stx1, stx2, and eae gene sequences. Identification of potentially pathogenic isolates from extensively used source water indicates that O157:H7 may be a significant but as yet underacknowledged public health concern in India.

Hamner, Steve; Broadaway, Susan C.; Mishra, Veer Bhadra; Tripathi, Anshuman; Mishra, Rajesh Kumar; Pulcini, Elinor; Pyle, Barry H.; Ford, Timothy E.

2007-01-01

147

Pathogens in livestock waste, their potential for movement through soil and environmental pollution  

Microsoft Academic Search

Livestock wastes contain many pathogenic microorganisms including bacteria, viruses and protozoa. Following the application of these wastes to land the potential exists for environmental contamination. Plants, soil and ultimately water courses which may subsequently be used as catchments for public water supplies may all be affected. Research attention is now being focused on this possibility, especially in the case of

Jane L. Mawdsley; Richard D. Bardgett; Roger J. Merry; Brian F. Pain; Michael K. Theodorou

1995-01-01

148

Identification of Potentially Human-Pathogenic Enterocytozoon bieneusi Genotypes in Various Birds?  

PubMed Central

Enterocytozoon bieneusi was detected in 24 of 83 samples from birds of the orders Columbiformes, Passeriformes, and Psittaciformes. It was identical to or closely related to the Peru6 genotype, which was previously found in humans in Peru. Thus, various birds can be a significant source of environmental contamination by potentially human-pathogenic E. bieneusi.

Lobo, Maria Luisa; Xiao, Lihua; Cama, Vitaliano; Magalhaes, Nuno; Antunes, Francisco; Matos, Olga

2006-01-01

149

Potential of two nucleic acid amplification assays for quantifying mycobacterial load in respiratory and non-respiratory specimens: a prospective study.  

PubMed

Quantification of bacillary load plays a critical prognostic role in tuberculosis patients. This study evaluated the potential of the Cepheid GeneXpert (GX) MTB/RIF and the BD ProbeTec system as quantitative assays. The time to positivity (TTP) measured by the Mycobacterial Growth Index Tube system was compared to the cycle threshold (Ct) of GX MTB/RIF and the Metric Other than Acceleration (MOTA) scores generated by the ProbeTec system. Out of 714 samples examined, 44 culture confirmed cases were identified. The Ct values in 21 respiratory samples showed a high linear fit with the TTP in liquid culture (Spearman's correlation coefficient r = 0.9, P value < 0.0001), which was not the case in 23 non-respiratory samples. In both types of specimens, the MOTA scores did not correlate with the TTP in liquid culture. This indicates the suitability of GX as a quantitative measurement of mycobacterial load in respiratory but not non-respiratory specimens. PMID:24369994

Alnimr, Amani Mansour; Hassan, Manal Ismail

2014-03-01

150

Nsp9 and Nsp10 Contribute to the Fatal Virulence of Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Emerging in China  

PubMed Central

Atypical porcine reproductive and respiratory syndrome (PRRS), which is caused by the Chinese highly pathogenic PRRS virus (HP-PRRSV), has resulted in large economic loss to the swine industry since its outbreak in 2006. However, to date, the region(s) within the viral genome that are related to the fatal virulence of HP-PRRSV remain unknown. In the present study, we generated a series of full-length infectious cDNA clones with swapped coding regions between the highly pathogenic RvJXwn and low pathogenic RvHB-1/3.9. Next, the in vitro and in vivo replication and pathogenicity for piglets of the rescued chimeric viruses were systematically analyzed and compared with their backbone viruses. First, we swapped the regions including the 5?UTR+ORF1a, ORF1b, and structural proteins (SPs)-coding region between the two viruses and demonstrated that the nonstructural protein-coding region, ORF1b, is directly related to the fatal virulence and increased replication efficiency of HP-PRRSV both in vitro and in vivo. Furthermore, we substituted the nonstructural protein (Nsp) 9-, Nsp10-, Nsp11- and Nsp12-coding regions separately; or Nsp9- and Nsp10-coding regions together; or Nsp9-, Nsp10- and Nsp11-coding regions simultaneously between the two viruses. Our results indicated that the HP-PRRSV Nsp9- and Nsp10-coding regions together are closely related to the replication efficiency in vitro and in vivo and are related to the increased pathogenicity and fatal virulence for piglets. Our findings suggest that Nsp9 and Nsp10 together contribute to the fatal virulence of HP-PRRSV emerging in China, helping to elucidate the pathogenesis of this virus.

Zhang, Jialong; Ge, Xinna; Zhou, Rong; Zheng, Huaguo; Geng, Gang; Guo, Xin; Yang, Hanchun

2014-01-01

151

Antibiotic resistance patterns among respiratory pathogens at a german university children’s hospital over a period of 10 years  

Microsoft Academic Search

Growing antimicrobial resistance among Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis is raising major concern worldwide. Strains of S. pneumoniae, H. influenzae and M. catarrhalis isolated from children with respiratory tract as well as invasive infection in a South-Western region of Germany between 1993 and 2002 were tested for susceptibility to common antibiotics including penicillins, cephalosporins and macrolides. A total

Sandra J. Arri; Kirsten Fluegge; Urban Mueller; Reinhard Berner

2006-01-01

152

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.

2014-01-01

153

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.

Sekse, Camilla; Sunde, Marianne; Hopp, Petter; Bruheim, Torkjel; Cudjoe, Kofitsyo Sewornu; Kvitle, Bj?rg

2013-01-01

154

Occurrence of potentially human-pathogenic Escherichia coli O103 in Norwegian sheep.  

PubMed

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; Urdahl, Anne Margrete

2013-12-01

155

Bacterial inclusion bodies as potential synthetic devices for pathogen recognition and a therapeutic substance release  

PubMed Central

Background Adhesins of pathogens recognise the glycans on the host cell and mediate adherence. They are also crucial for determining the tissue preferences of pathogens. Currently, glyco-nanomaterials provide potential tool for antimicrobial therapy. We demonstrate that properly glyco-tailored inclusion bodies can specifically bind pathogen adhesins and release therapeutic substances. Results In this paper, we describe the preparation of tailored inclusion bodies via the conjugation of indicator protein aggregated to form inclusion bodies with soluble proteins. Whereas the indicator protein represents a remedy, the soluble proteins play a role in pathogen recognition. For conjugation, glutaraldehyde was used as linker. The treatment of conjugates with polar lysine, which was used to inactivate the residual glutaraldehyde, inhibited unwanted hydrophobic interactions between inclusion bodies. The tailored inclusion bodies specifically interacted with the SabA adhesin from Helicobacter pylori aggregated to form inclusion bodies that were bound to the sialic acids decorating the surface of human erythrocytes. We also tested the release of indicator proteins from the inclusion bodies using sortase A and Ssp DNAB intein self-cleaving modules, respectively. Sortase A released proteins in a relatively short period of time, whereas the intein cleavage took several weeks. Conclusions The tailored inclusion bodies are promising “nanopills” for biomedical applications. They are able to specifically target the pathogen, while a self-cleaving module releases a soluble remedy. Various self-cleaving modules can be enabled to achieve the diverse pace of remedy release.

2013-01-01

156

Mitochondrial respiratory pathways inhibition in Rhizopus oryzae potentiates activity of posaconazole and itraconazole via apoptosis.  

PubMed

The incidence of mucormycosis has increased drastically in immunocompromised patients. Also the array of targets whose inhibition results in Mucorales death is limited. Recently, researchers identified mitochondria as important regulators of detoxification and virulence mechanisms in fungi. In this context, targeting the mitochondrial respiratory chain may provide a new platform for antifungal development. We hypothesized that targeting respiratory pathways potentiates triazoles activity via apoptosis. We found that simultaneous administration of antimycin A (AA) and benzohydroxamate (BHAM), inhibitors of classical and alternative mitochondrial pathways respectively, resulted in potent activity of posaconazole (PCZ) and itraconazole (ICZ) against Rhizopus oryzae. We observed cellular changes characteristic of apoptosis in R. oryzae cells treated with PCZ or ICZ in combination with AA and BHAM. The fungicidal activity of this combination against R. oryzae was correlated with intracellular reactive oxygen species accumulation (ROS), phosphatidylserine externalization, mitochondrial membrane depolarization, and increased caspase like activity. DNA fragmentation and condensation assays also revealed apoptosis of R. oryzae cells. These apoptotic features were prevented by the addition of the ROS scavenger N-acetyl-cysteine. Taken together, these findings suggest that the use of PCZ or ICZ in combination with AA and BHAM makes R. oryzae exquisitely sensitive to treatment with triazoles via apoptosis. This strategy may serve as a new model for the development of improved or novel antifungal agents. PMID:23696824

Shirazi, Fazal; Kontoyiannis, Dimitrios P

2013-01-01

157

Screening of Swiss hot spring resorts for potentially pathogenic free-living amoebae.  

PubMed

Free-living amoebae (FLA) belonging to Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris, and Sappinia pedata are known to cause infections in humans and animals leading to severe brain pathologies. Worldwide, warm aquatic environments have been found to be suitable habitats for pathogenic FLA. The present study reports on screening for potentially pathogenic FLA in four hot spring resorts in Switzerland. Water samples were taken from water filtration units and from the pools, respectively. Amoebae isolated from samples taken during, or before, the filtration process were demonstrated to be morphologically and phylogenetically related to Stenoamoeba sp., Hartmannella vermiformis, Echinamoeba exundans, and Acanthamoeba healyi. With regard to the swimming pools, FLA were isolated only in one resort, and the isolate was identified as non-pathogenic and as related to E. exundans. Further investigations showed that the isolates morphologically and phylogenetically related to A. healyi displayed a pronounced thermotolerance, and exhibited a marked in vitro cytotoxicity upon 5-day exposure to murine L929 fibroblasts. Experimental intranasal infection of Rag2-immunodeficient mice with these isolates led to severe brain pathologies, and viable trophozoites were isolated from the nasal mucosa, brain tissue, and lungs post mortem. In summary, isolates related to A. healyi were suggestive of being potentially pathogenic to immunocompromised persons. However, the presence of these isolates was limited to the filtration units, and an effective threat for health can therefore be excluded. PMID:20036656

Gianinazzi, Christian; Schild, Marc; Zumkehr, Beatrice; Wüthrich, Fritz; Nüesch, Irina; Ryter, Regula; Schürch, Nadia; Gottstein, Bruno; Müller, Norbert

2010-09-01

158

Contamination of community water sources by potentially pathogenic vibrios following sea water inundation.  

PubMed

Potentially pathogenic members of the Vibrionaceae family including Vibrio cholerae and Vibrio parahemolyticus were isolated from domestic sources of drinking water in coastal villages following sea water inundation during the tsunami in Southern India. Phenotypic and genotypic studies were done to confirm the identity and detection of toxins. Vibrio-gyr (gyrase B gene) was detected in all sixteen vibrio isolates. Toxin regulating genes i.e.: ctx gene, tdh gene, and trh gene, however were not detected in any of the strains, thereby ruling out presence of toxins which could endanger human life. Other potentially pathogenic bacteria Aeromonas and Plesiomonas were also isolated from hand pumps and wells, in a few localities. There was no immediate danger in the form of an outbreak or sporadic gastroenteritis at the time of the study. Timely chlorination and restoration of potable water supply to the flood affected population by governmental and nongovernmental agencies averted waterborne gastroenteritis. Assessment of quality of water and detection of potential virulent organisms is an important public health activity following natural disasters. This work highlights the importance of screening water sources for potentially pathogenic microorganisms after natural disasters to avert outbreaks of gastroenteritis and other infectious diseases. PMID:18697592

Kanungo, Reba; Shashikala; Karunasagar, I; Srinivasan, S; Sheela, Devi; Venkatesh, K; Anitha, P

2007-12-01

159

Bartonella Infection in Animals: Carriership, Reservoir Potential, Pathogenicity, and Zoonotic Potential for Human Infection  

PubMed Central

Recent observations have begun to support a role for Bartonella spp. as animal as well as human pathogens. Bartonella spp. are vector-transmitted, blood-borne, intracellular, gram-negative bacteria that can induce prolonged infection in the host. Persistent infections in domestic and wild animals result in a substantial reservoir of Bartonella organisms in nature that can serve as a source for inadvertent human infection. The prevalence of bacteremia can range from 50 to 95% in selected rodent, cat, deer, and cattle populations. Dogs infected with Bartonella spp. can develop lameness, endocarditis, granulomatous lymphadenitis, and peliosis hepatis, lesions that have also been reported in association with human infection. Understanding the role of Bartonella spp. as pathogens in cats and other wild or domestic animals awaits the results of additional studies. Considering the extensive animal reservoirs and the large number of insects that have been implicated in the transmission of Bartonella spp., both animal and human exposure to these organisms may be more substantial than is currently believed.

Breitschwerdt, Edward B.; Kordick, Dorsey L.

2000-01-01

160

Determinants of Microbial Pathogenicity.  

National Technical Information Service (NTIS)

The terms of pathogenicity and virulence are synonymous; they mean the capacity to produce disease. To be pathogenic a microorganism must be able to: (1) Infect the mucous surfaces of the respiratory, alimentary or urogenital tracts. Some microbes are int...

H. Smith

1984-01-01

161

German Cockroaches (Blattella Germanica L.) as a Potential Source of Pathogens Causing Nosocomial Infections  

Microsoft Academic Search

German cockroaches collected in two hospitals were examined bacteriologically. Twenty strains of different taxons were isolated, all considered to be potentially pathogenic to humans. Some strains were resistant to antibacterial drugs widely used for treatment of patients: Gram-negative rods were resistant to amoxicillin\\/clavulanic acid, Pseudomonas spp. additionally resistant to co-trimoxasole. Strains of Staphylococcus equorum, S. hominis were methicillin-resistant, a strain

A. Gliniewicz; E. Czajka; A. E. Laudy; M. Kochman; K. Grzegorzak; B. Sawicka; H. Stypulkowska-Misiurewicz; K. Pancer

2003-01-01

162

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.

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

2013-01-01

163

Changes in epithelial secretory cells and potentiation of neurogenic inflammation in the trachea of rats with respiratory tract infections  

Microsoft Academic Search

In rats respiratory tract infections due to Sendai virus and coronavirus usually are transient, but they can have long-lasting consequences when accompanied by Mycoplasma pulmonis infections. Morphological alterations in the tracheal epithelium and a potentiation of the inflammatory response evoked by sensory nerve stimulation (“neurogenic inflammation”) are evident nine weeks after the infections begin, but the extent to which these

Hung-Tu Huang; Amy Haskell; Donald M. McDonald

1989-01-01

164

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.

2012-01-01

165

The effect of glyphosate on potential pathogens and beneficial members of poultry microbiota in vitro.  

PubMed

The use of glyphosate modifies the environment which stresses the living microorganisms. The aim of the present study was to determine the real impact of glyphosate on potential pathogens and beneficial members of poultry microbiota in vitro. The presented results evidence that the highly pathogenic bacteria as Salmonella Entritidis, Salmonella Gallinarum, Salmonella Typhimurium, Clostridium perfringens and Clostridium botulinum are highly resistant to glyphosate. However, most of beneficial bacteria as Enterococcus faecalis, Enterococcus faecium, Bacillus badius, Bifidobacterium adolescentis and Lactobacillus spp. were found to be moderate to highly susceptible. Also Campylobacter spp. were found to be susceptible to glyphosate. A reduction of beneficial bacteria in the gastrointestinal tract microbiota by ingestion of glyphosate could disturb the normal gut bacterial community. Also, the toxicity of glyphosate to the most prevalent Enterococcus spp. could be a significant predisposing factor that is associated with the increase in C. botulinum-mediated diseases by suppressing the antagonistic effect of these bacteria on clostridia. PMID:23224412

Shehata, Awad A; Schrödl, Wieland; Aldin, Alaa A; Hafez, Hafez M; Krüger, Monika

2013-04-01

166

Molecular detection of CF lung pathogens: current status and future potential.  

PubMed

Molecular diagnostic tests, based on the detection and identification of nucleic acids in human biological samples, are increasingly employed in the diagnosis of infectious diseases and may be of future benefit to CF microbiology services. Our growing understanding of the complex polymicrobial nature of CF airway infection has highlighted current and likely future shortcomings in standard diagnostic practices. Failure to detect fastidious or slow growing microbes and misidentification of newly emerging pathogens could potentially be addressed using culture-independent molecular technologies with high target specificity. This review considers existing molecular diagnostic tests in the context of the key requirements for an envisaged CF microbiology focussed assay. The issues of assay speed, throughput, detection of multiple pathogens, data interpretation and antimicrobial susceptibility testing are discussed. PMID:23402821

Pattison, Sally H; Rogers, Geraint B; Crockard, Martin; Elborn, J Stuart; Tunney, Michael M

2013-05-01

167

A potential link between bacterial pathogens and allergic conjunctivitis by dendritic cells.  

PubMed

The association and mechanism of bacteria linking to the allergic inflammation have not been well elucidated. This study was to explore a potential link between bacterial pathogens and allergic conjunctivitis by dendritic cells (DCs). Bone marrow-derived DCs from BALB/c and MyD88 knockout mice were treated with or without bacterial pathogens or thymic stromal lymphopoietin (TSLP). Two murine models of the topical challenge with LPS or flagellin and experimental allergic conjunctivitis (EAC) were used for in vivo study. The mRNA expression was determined by reverse transcription and real time PCR, and protein production was evaluated by ELISA, Western blotting, immunofluorescent staining and flow cytometry. TSLP mRNA and protein were found to be largely induced by DCs challenged with microbial pathogens, highly by lipopolysaccharide (LPS) and flagellin. The expression of MyD88, NF?B1, NF?B2 and RelA accompanied by NF?B p65 nuclear translocation and TSLP induction were significantly stimulated by flagellin, but blocked by TLR5 antibody or NF?B inhibitor in DCs from MyD88(+/+) but not MyD88(-/-) mice. TSLP promoted the expression of CD40, CD80, OX40 ligand (OX40L), IL-13 and CCL17 by DCs. TSLP-producing DCs were identified in vivo in ocular surface conjunctiva and draining cervical lymph nodes from two murine models of topical challenge with LPS or flagellin, and EAC in BALB/c mice. TSLP/TSLPR/OX40L signaling was observed in DCs of EAC mice. Our findings demonstrate that DCs not only respond to TSLP, but also produce TSLP via TLR/MyD88/NF?B pathways in response to bacterial pathogens, suggesting a potential link between bacteria and allergic disease. PMID:24486456

Deng, Ruzhi; Su, Zhitao; Lu, Fan; Zhang, Lili; Lin, Jing; Zhang, Xiaobo; de Paiva, Cintia S; Pflugfelder, Stephen C; Li, De-Quan

2014-03-01

168

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

169

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

170

Potential therapeutic implications of new insights into respiratory syncytial virus disease  

Microsoft Academic Search

Viral bronchiolitis is the most common cause of hospitalization in infants under 6 months of age, and 70% of all cases of bronchiolitis are caused by respiratory syncytial virus (RSV). Early RSV infection is associated with respiratory problems such as asthma and wheezing later in life. RSV infection is usually spread by contaminated secretions and infects the upper then lower

Peter JM Openshaw

2002-01-01

171

Elucidation of bacteria found in car interiors and strategies to reduce the presence of potential pathogens  

PubMed Central

The human microbiome is influenced by a number of factors, including environmental exposure to microbes. Because many humans spend a large amount of time in built environments, it can be expected that the microbial ecology of these environments will influence the human microbiome. In an attempt to further understand the microbial ecology of built environments, the microbiota of car interiors was analyzed using culture dependent and culture independent methods. While it was found that the number and type of bacteria varied widely among the cars and sites tested, Staphylococcus and Propionibacterium were nearly always the dominant genera found at the locations sampled. Because Staphylococcus is of particular concern to human health, the characteristics of this genus found in car interiors were investigated. Staphylococcus epidermidis, S. aureus, and S. warnerii were the most prevalent staphylococcal species found, and 22.6% of S. aureus strains isolated from shared community vehicles were resistant to methicillin. The reduction in the prevalence of pathogenic bacteria in cars by using silver-based antimicrobial surface coatings was also evaluated. Coatings containing 5% silver ion additives were applied to steering wheels, placed in cars for five months and were found to eliminate the presence of culturable pathogenic bacteria recovered from these sites relative to controls. Together, these results provide new insight into the microbiota found in an important built environment, the automobile, and potential strategies for controlling the presence of human pathogens.

Stephenson, Rachel E.; Gutierrez, Daniel; Peters, Cindy; Nichols, Mark; Boles, Blaise R.

2014-01-01

172

Genotyping of Environmental and Clinical Stenotrophomonas maltophilia Isolates and their Pathogenic Potential  

PubMed Central

Stenotrophomonas maltophilia is a highly versatile species with useful biotechnological potential but also with pathogenic properties. In light of possible differences in virulence characteristics, knowledge about genomic subgroups is therefore desirable. Two different genotyping methods, rep-PCR fingerprinting and partial gyrB gene sequencing were used to elucidate S. maltophilia intraspecies diversity. Rep-PCR fingerprinting revealed the presence of 12 large subgroups, while gyrB gene sequencing distinguished 10 subgroups. For 8 of them, the same strain composition was shown with both typing methods. A subset of 59 isolates representative for the gyrB groups was further investigated with regards to their pathogenic properties in a virulence model using Dictyostelium discoideum and Acanthamoeba castellanii as host organisms. A clear tendency towards accumulation of virulent strains could be observed for one group with A. castellanii and for two groups with D. discoideum. Several virulent strains did not cluster in any of the genetic groups, while other groups displayed no virulence properties at all. The amoeba pathogenicity model proved suitable in showing differences in S. maltophilia virulence. However, the model is still not sufficient to completely elucidate virulence as critical for a human host, since several strains involved in human infections did not show any virulence against amoeba.

Adamek, Martina; Overhage, Jorg; Bathe, Stephan; Winter, Josef; Fischer, Reinhard; Schwartz, Thomas

2011-01-01

173

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.

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

2011-01-01

174

Subtype distribution of Blastocystis isolates identified in a Sydney population and pathogenic potential of Blastocystis.  

PubMed

Blastocystis is one of the most common enteric parasites present in humans. There is still much uncertainty about the pathogenic potential of this parasite, and it was suggested that its pathogenicity could be subtype-related. This report aimed to study 98 Blastocystis isolates found in human stool specimens to identify the subtypes present and carry out phylogenetic analysis on these isolates. This study also aimed to show the relationship between subtype and symptoms. Five-hundred and thirteen stool samples were submitted to five different diagnostic techniques for the detection of Blastocystis. Polymerase chain reaction (PCR)-positive samples were then sequenced and the small subunit (SSU) rDNA sequences were aligned and submitted to phylogenetic analysis. Ninety-eight samples were positive by any of the diagnostic methods for Blastocystis and 96 were positive by PCR. There were seven different subtypes (1, 2, 3, 4, 6, 7 and 8) identified by PCR and sequencing. This is the first large-scale study to examine the occurrence of Blastocystis in Australia. This study reports the high incidence of subtype 3 (44 %) in this population and discusses the emerging idea of subtype-dependent pathogenicity. PMID:22996007

Roberts, T; Stark, D; Harkness, J; Ellis, J

2013-03-01

175

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

176

Respiratory syncytial virus (RSV) infection induces cyclooxygenase 2: a potential target for RSV therapy.  

PubMed

Cyclooxygenases (COXs) are rate-limiting enzymes that initiate the conversion of arachidonic acid to prostanoids. COX-2 is the inducible isoform that is up-regulated by proinflammatory agents, initiating many prostanoid-mediated pathological aspects of inflammation. The roles of cyclooxygenases and their products, PGs, have not been evaluated during respiratory syncytial virus (RSV) infection. In this study we demonstrate that COX-2 is induced by RSV infection of human lung alveolar epithelial cells with the concomitant production of PGs. COX-2 induction was dependent on the dose of virus and the time postinfection. PG production was inhibited preferentially by NS-398, a COX-2-specific inhibitor, and indomethacin, a pan-COX inhibitor, but not by SC-560, a COX-1-specific inhibitor. In vivo, COX-2 mRNA expression and protein production were strongly induced in the lungs and cells derived from bronchioalveolar lavage of cotton rats infected with RSV. The pattern of COX-2 expression in vivo in lungs is cyclical, with a final peak on day 5 that correlates with maximal histopathology. Treatment of cotton rats with indomethacin significantly mitigated lung histopathology produced by RSV. The studies described in this study provide the first evidence that COX-2 is a potential therapeutic target in RSV-induced disease. PMID:15778400

Richardson, Joann Y; Ottolini, Martin G; Pletneva, Lioubov; Boukhvalova, Marina; Zhang, Shuling; Vogel, Stefanie N; Prince, Gregory A; Blanco, Jorge C G

2005-04-01

177

Ambroxol: a multifaceted molecule with additional therapeutic potentials in respiratory disorders of childhood.  

PubMed

Introduction: Mucoactive drugs are currently used to cleanse the respiratory tract following disturbance of the normal mucociliary clearance due to mucous hyperproduction and/or modification of its physicochemical characteristics. However, in addition to possessing the ability to perform specific actions on airway secretion, these compounds have the capability to modulate the mechanisms involved in abnormal secretions. Indeed, over the years, in the postmarketing phase, a large number of studies have been published showing interesting pharmacological activities in addition to their secretagogue activity. Areas covered: This article collates available data on ambroxol (2-amino-3,5-dibromo-N-[trans-4-hydroxycyclohexyl]benzylamine), a metabolite of bromhexine, used as a secretagogue in the treatment of childhood airway diseases. This article goes beyond the mucoactive aspects of the drug covering its multiple pharmacological properties. Expert opinion: The non-mucoactive functions exhibited by the compound may provide beneficial effects on airway structure and function in health and disease. Beyond the mucokinetic and secretagogue effects, ambroxol showed great antioxidant, anti-inflammatory, local anesthetic and surfactant synthesis stimulatory activities. Moreover, some antiviral and antibacterial activities were shown. These findings may better explain the clinical results observed in a variety of airway disorders and suggest additional therapeutic potential. Further studies are needed to better define the clinical relevance of these non-mucolytic activities. PMID:22646987

Paleari, Davide; Rossi, Giovanni A; Nicolini, Gabriele; Olivieri, Dario

2011-11-01

178

The Pathogenic Potential of Campylobacter concisus Strains Associated with Chronic Intestinal Diseases  

PubMed Central

Campylobacter concisus has garnered increasing attention due to its association with intestinal disease, thus, the pathogenic potential of strains isolated from different intestinal diseases was investigated. A method to isolate C. concisus was developed and the ability of eight strains from chronic and acute intestinal diseases to adhere to and invade intestinal epithelial cells was determined. Features associated with bacterial invasion were investigated using comparative genomic analyses and the effect of C. concisus on host protein expression was examined using proteomics. Our isolation method from intestinal biopsies resulted in the isolation of three C. concisus strains from children with Crohn's disease or chronic gastroenteritis. Four C. concisus strains from patients with chronic intestinal diseases can attach to and invade host cells using mechanisms such as chemoattraction to mucin, aggregation, flagellum-mediated attachment, “membrane ruffling”, cell penetration and damage. C. concisus strains isolated from patients with chronic intestinal diseases have significantly higher invasive potential than those from acute intestinal diseases. Investigation of the cause of this increased pathogenic potential revealed a plasmid to be responsible. 78 and 47 proteins were upregulated and downregulated in cells infected with C. concisus, respectively. Functional analysis of these proteins showed that C. concisus infection regulated processes related to interleukin-12 production, proteasome activation and NF-?B activation. Infection with all eight C. concisus strains resulted in host cells producing high levels of interleukin-12, however, only strains capable of invading host cells resulted in interferon-? production as confirmed by ELISA. These findings considerably support the emergence of C. concisus as an intestinal pathogen, but more significantly, provide novel insights into the host immune response and an explanation for the heterogeneity observed in the outcome of C. concisus infection. Moreover, response to infection with invasive strains has substantial similarities to that observed in the inflamed mucosa of Crohn's disease patients.

Kaakoush, Nadeem O.; Deshpande, Nandan P.; Wilkins, Marc R.; Tan, Chew Gee; Burgos-Portugal, Jose A.; Raftery, Mark J.; Day, Andrew S.; Lemberg, Daniel A.; Mitchell, Hazel

2011-01-01

179

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

180

Evaluation of the efficacy of an attenuated live vaccine against highly pathogenic porcine reproductive and respiratory syndrome virus in young pigs.  

PubMed

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 (10(5.0) 50% tissue culture infective doses [TCID(50)]) 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; Wu, Hua

2012-08-01

181

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.

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

2012-01-01

182

Fluorescence in situ hybridization investigation of potentially pathogenic bacteria involved in neonatal porcine diarrhea  

PubMed Central

Background Neonatal diarrhea is a multifactorial condition commonly present on pig farms and leads to economic losses due to increased morbidity and mortality of piglets. Immature immune system and lack of fully established microbiota at birth predispose neonatal piglets to infection with enteric pathogens. The microorganisms that for decades have been associated with enteritis and diarrhea in suckling piglets are: rotavirus A, coronavirus, enterotoxigenic Escherichia coli (ETEC), Clostridium perfringens type C, Cryptosporidium spp., Giardia spp., Cystoisospora suis and Strongyloides ransomi. However, in recent years, the pig industry has experienced an increased number of neonatal diarrhea cases in which the above mentioned pathogens are no longer detected. Potentially pathogenic bacteria have recently received focus in the research on the possible etiology of neonatal diarrhea not caused by common pathogens. The primary aim of this study was to investigate the role of E. coli, Enterococcus spp., C. perfringens and C. difficile in the pathogenesis of neonatal porcine diarrhea with no established casual agents. Fluorescence in situ hybridization with oligonucleotide probes was applied on the fixed intestinal tissue samples from 51 diarrheic and 50 non-diarrheic piglets collected from four Danish farms during outbreaks of neonatal diarrhea not caused by well-known enteric pathogens. Furthermore, an association between the presence of these bacteria and histological lesions was evaluated. Results The prevalence of fluorescence signals specific for E. coli, C. perfringens and C. difficile was similar in both groups of piglets. However, Enterococcus spp. was primarily detected in the diarrheic piglets. Furthermore, adherent bacteria were detected in 37 % diarrheic and 14 % non-diarrheic piglets. These bacteria were identified as E. coli and Enterococcus spp. and their presence in the intestinal mucosa was associated with histopathological changes. Conclusions The results of this study showed that simultaneous colonization of the intestinal mucosa by adherent non-ETEC E. coli and Enterococcus spp. can be involved in the pathogenesis of neonatal porcine diarrhea. These bacteria should be considered in diagnosis of diarrhea in piglets, when detection of common, well-known enteric agents is unsuccessful.

2014-01-01

183

Saffold cardioviruses of 3 lineages in children with respiratory tract infections, Beijing, China.  

PubMed

To clarify the potential for respiratory transmission of Saffold cardiovirus (SAFV) and characterize the pathogen, we analyzed respiratory specimens from 1,558 pediatric patients in Beijing. We detected SAFV in 7 (0.5%) patients and identified lineages 1-3. However, because 3 patients had co-infections, we could not definitively say SAFV caused disease. PMID:20587195

Ren, Lili; Gonzalez, Richard; Xie, Zhengde; Xiao, Yan; Li, Yongjun; Liu, Chunyan; Chen, Lan; Yang, Qingqing; Vernet, Guy; Paranhos-Baccalà, Glaucia; Jin, Qi; Shen, Kunling; Wang, Jianwei

2010-07-01

184

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

185

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

186

Induction of cyclooxygenase-2 signaling by Stomatococcus mucilaginosus highlights the pathogenic potential of an oral commensal.  

PubMed

Stomatococcus mucilaginosus is an oral commensal that has been occasionally reported to cause severe infections in immunocompromised patients. There is no information about the pathogenic role of S. mucilaginosus in airway infections. In a cohort of 182 subjects with bronchiectasis, we found that 9% were colonized with S. mucilaginosus in their lower airways by culture growth from bronchoalveolar lavage. To address the pathogenic potential of S.mucilaginosus, we developed a murine model of S. mucilaginosus lung infection. Intratracheal injection of S. mucilaginosus in C57BL/6 mice resulted in a neutrophilic influx with production of proinflammatory cytokines, chemokines, and lipid mediators, mainly PGE? with induction of cyclooxygenase-2 (COX-2) in the lungs. Presence of TLR2 was necessary for induction of COX-2 and production of PGE? by S. mucilaginosus. TLR2-deficient mice showed an enhanced clearance of S. mucilaginosus compared with wild-type mice. Administration of PGE? to TLR2(-/-) mice resulted in impaired clearance of S. mucilaginosus, suggesting a key role for COX-2-induced PGE? production in immune response to S. mucilaginosus. Mechanistically, induction of COX-2 in macrophages was dependent on the p38-ERK/MAPK signaling pathway. Furthermore, mice treated with S. mucilaginosus and Pseudomonas aeruginosa showed an increased mortality compared with mice treated with PA103 or S. mucilaginosus alone. Inhibition of COX-2 significantly improved survival in mice infected with PA103 and S. mucilaginosus. These data provide novel insights into the bacteriology and personalized microbiome in patients with bronchiectasis and suggest a pathogenic role for S. mucilaginosus in patients with bronchiectasis. PMID:24018272

Yuan, Zhihong; Panchal, Dipti; Syed, Mansoor Ali; Mehta, Hiren; Joo, Myungsoo; Hadid, Walid; Sadikot, Ruxana T

2013-10-01

187

Dendryphion penicillatum and Pleospora papaveracea, Destructive Seedborne Pathogens and Potential Mycoherbicides for Papaver somniferum.  

PubMed

ABSTRACT Dendryphion penicillatum and Pleospora papaveracea were isolated from blighted Papaver somniferum and Papaver bracteatum plants grown in growth chambers and the field in Beltsville, MD. The etiology of the diseases was determined, and the fungi are being investigated as potential mycoherbicides to control the narcotic opium poppy plant. P. papaveracea is known to be a highly destructive seedborne pathogen of Papaver somniferum, causing seedling blight, leaf blight, crown rot, and capsule rot. Single conidia and ascospores were isolated and cultures established from naturally infested seed and diseased foliage and pods of opium poppy from Iran, Colombia, Venezuela, Sweden, India, and the United States (Maryland and Washington). Mycelia and conidia of P. papaveracea and D. penicillatum produced on necrotic leaf tissues appear morphologically similar, and the fungi were previously considered to be anamorph and teleomorph. However, no anamorph/teleomorph connection could be established, and the fungi appear to be distinct taxa. P. papaveracea produced conidia, mature pseudothecia, and chlamydospores in vitro and on infected stems. D. penicillatum produced conidia, microsclerotia, and macronematous conidiophores. Although both fungi were pathogenic to three poppy cultivars, conidial inoculum from P. papaveracea cultures was more virulent than conidial inoculum from D. penicillatum. Eight-week-old plants became necrotic and died 8 days after inoculation with a conidial suspension of P. papaveracea at 2 x 10(5) spores per ml. Disease severity was significantly enhanced by inoculum formulations that contained corn oil, by higher conidial inoculum concentrations, and by increased wetness periods. Symptoms on plants inoculated with either pathogen included leaf and stem necrosis, stem girdling, stunting, necrotic leaf spots, and foliar and pod blight. Inoculated seedlings exhibited wire stem, damping-off, and root rot. Conidia, and less frequently pseudothecia, of P. papaveracea and conidia of D. penicillatum were produced abundantly on inoculated, necrotic foliage, pods, and seedlings. Cultures from conidia or ascospores reisolated from these tissues consistently produced fungi whose morphologies were typical of the fungus from which the inoculum was derived. PMID:18944487

O'Neill, N R; Jennings, J C; Bailey, B A; Farr, D F

2000-07-01

188

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

189

Contribution of Plasminogen Activation towards the Pathogenic Potential of Oral Streptococci  

PubMed Central

Oral streptococci are a heterogeneous group of human commensals, with a potential to cause serious infections. Activation of plasminogen has been shown to increase the virulence of typical human pathogenic streptococci such as S. pneumoniae. One important factor for plasminogen activation is the streptococcal ?-enolase. Here we report that plasminogen activation is also common in oral streptococci species involved in clinical infection and that it depends on the action of human plasminogen activators. The ability to activate plasminogen did not require full conservation of the internal plasminogen binding sequence motif FYDKERKVY of ?-enolase that was previously described as crucial for increased plasminogen binding, activation and virulence. Instead, experiments with recombinant ?-enolase variants indicate that the naturally occurring variations do not impair plasminogen binding. In spite of these variations in the internal plasminogen binding motif oral streptococci showed similar activation of plasminogen. We conclude that the pathomechanism of plasminogen activation is conserved in oral streptococci that cause infections in human. This may contribute to their opportunistic pathogenic character that is unfurled in certain niches.

Itzek, Andreas; Gillen, Christine M.; Fulde, Marcus; Friedrichs, Claudia; Rodloff, Arne C.; Chhatwal, Gursharan S.; Nitsche-Schmitz, Daniel Patric

2010-01-01

190

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

191

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

PubMed Central

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 three samplings carried out in 2006-2007 in public parks and gardens in Madrid, Spain. Standard haematological and morphological analyses were carried out on the pigeons. PCR was used to screen for the presence of Campylobacter jejuni, C. coli and Chlamydophila psittaci. Positive samples were confirmed by DNA sequencing. Results The analyses demonstrated a high prevalence of Chlamydophila psittaci (52.6%) and Campylobacter jejuni (69.1%) among the birds captured. In contrast, Campylobacter coli was rarely detected (1.1%). Conclusions Pigeons in Madrid can carry Chlamydophila psittaci and Campylobacter jejuni. They may be asymptomatic or subclinical carriers of both pathogens.

2010-01-01

192

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.

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

2014-01-01

193

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.

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

2014-01-01

194

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

PubMed

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; Feng, Wen-Hai

2014-06-01

195

Predatory bacteria: a potential ally against multidrug-resistant Gram-negative pathogens.  

PubMed

Multidrug-resistant (MDR) Gram-negative bacteria have emerged as a serious threat to human and animal health. Bdellovibrio spp. and Micavibrio spp. are Gram-negative bacteria that prey on other Gram-negative bacteria. In this study, the ability of Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus to prey on MDR Gram-negative clinical strains was examined. Although the potential use of predatory bacteria to attack MDR pathogens has been suggested, the data supporting these claims is lacking. By conducting predation experiments we have established that predatory bacteria have the capacity to attack clinical strains of a variety of ß-lactamase-producing, MDR Gram-negative bacteria. Our observations indicate that predatory bacteria maintained their ability to prey on MDR bacteria regardless of their antimicrobial resistance, hence, might be used as therapeutic agents where other antimicrobial drugs fail. PMID:23650563

Kadouri, Daniel E; To, Kevin; Shanks, Robert M Q; Doi, Yohei

2013-01-01

196

Predatory Bacteria: A Potential Ally against Multidrug-Resistant Gram-Negative Pathogens  

PubMed Central

Multidrug-resistant (MDR) Gram-negative bacteria have emerged as a serious threat to human and animal health. Bdellovibrio spp. and Micavibrio spp. are Gram-negative bacteria that prey on other Gram-negative bacteria. In this study, the ability of Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus to prey on MDR Gram-negative clinical strains was examined. Although the potential use of predatory bacteria to attack MDR pathogens has been suggested, the data supporting these claims is lacking. By conducting predation experiments we have established that predatory bacteria have the capacity to attack clinical strains of a variety of ß-lactamase-producing, MDR Gram-negative bacteria. Our observations indicate that predatory bacteria maintained their ability to prey on MDR bacteria regardless of their antimicrobial resistance, hence, might be used as therapeutic agents where other antimicrobial drugs fail.

Kadouri, Daniel E.; To, Kevin; Shanks, Robert M. Q.; Doi, Yohei

2013-01-01

197

Pathogenic potential and genetic diversity of environmental and clinical isolates of Pseudomonas aeruginosa.  

PubMed

The aim of this study was to investigate the occurrence of virulence genes among clinical and environmental isolates of Pseudomonas aeruginosa and to establish their genetic relationships by Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR). A total of 60 P. aeruginosa isolates from environmental and clinical sources were studied. Of these, 20 bacterial isolates were from soil, 20 from water, and 20 from patients with cystic fibrosis. Analysis of ERIC-PCR demonstrated that the isolates of P. aeruginosa showed a considerable genetic variability, regardless of their habitat. Numerous virulence genes were detected in both clinical and environmental isolates, reinforcing the possible pathogenic potential of soil and water isolates. The results showed that the environmental P. aeruginosa has all the apparatus needed to cause disease in humans and animals. PMID:23879442

Martins, Vinicius Vicente; Pitondo-Silva, André; Manço, Luisa de Melo; Falcão, Juliana Pfrimer; Freitas, Sueli dos Santos; da Silveira, Wanderley Dias; Stehling, Eliana Guedes

2014-02-01

198

Effect of 1-methylascorbigen on the resistance potential of plants to pathogens.  

PubMed

We have studied the effect of 1'-methylascorbigen, an immunostimulating substance in animal systems on the resistance potential of barley, bean and wheat plants to the fungal pathogens Erysiphe graminis, Uromyces phaseoli and Puccinia recondita, respectively. The effectiveness of protection depends - as in the case of other endogenous, N-methylated compounds - on the dosage of applied 1'-methylascorbigen and on the time interval between the chemical pretreatment and inoculation. The time- and dose-dependent double immune response was clearly demonstrated in case of the barley - Erysiphe graminis and bean - Uromyces phaseoli host-parasite relationships while in case of the wheat -Puccinia recondita relationship the relatively long-time interval between pretreatment and inoculation allowed manifestation of only a single immune response. PMID:10526989

Kátay, G; Tyihák, E

1998-01-01

199

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

Microsoft Academic Search

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

Tim Frederik Weber; Ralf Tetzlaff; Fabian Rengier; Philipp Geisbuesch; Annette Kopp-Schneider; Dittmar Boeckler; Monika Eichinger; Hans-Ulrich Kauczor; Hendrik von Tengg-Kobligk

2009-01-01

200

Respiratory symptoms among glass bottle makers exposed to stannic chloride solution and other potentially hazardous substances  

Microsoft Academic Search

Concern about upper respiratory tract irritation and other symptoms among workers at a glass bottle manufacturing plant led to an epidemiologic and an industrial hygiene survey. Questionnaire responses from 35 hot end and 53 cold end workers indicated that the incidence of wheezing, chest pain, dyspnea on exertion, and cough was significantly elevated among hot end workers. Among both smokers

B. S. Levy; F. Davis; B. Johnson

1985-01-01

201

Potentially Human-Pathogenic Escherichia coli O26 in Norwegian Sheep Flocks ?  

PubMed Central

A national survey of Escherichia coli O26 in Norwegian sheep flocks was conducted, using fecal samples to determine the prevalence. In total, 491 flocks were tested, and E. coli O26 was detected in 17.9% of the flocks. One hundred forty-two E. coli O26 isolates were examined for flagellar antigens (H typing) and four virulence genes, including stx and eae, to identify possible Shiga toxin-producing E. coli (STEC) and enteropathogenic E. coli (EPEC). Most isolates (129 out of 142) were identified as E. coli O26:H11. They possessed eae and may have potential as human pathogens, although only a small fraction were identified as STEC O26:H11, giving a prevalence in sheep flocks of only 0.8%. Correspondingly, the sheep flock prevalence of atypical EPEC (aEPEC) O26:H11 was surprisingly high (15.9%). The genetic relationship between the E. coli O26:H11 isolates was investigated by pulsed-field gel electrophoresis (PFGE) and multilocus variable number tandem repeat analysis (MLVA), identifying 63 distinct PFGE profiles and 22 MLVA profiles. Although the MLVA protocol was less discriminatory than PFGE and a few cases of disagreement were observed, comparison by partition mapping showed an overall good accordance between the two methods. A close relationship between a few isolates of aEPEC O26:H11 and STEC O26:H11 was identified, but all the E. coli O26:H11 isolates should be considered potentially pathogenic to humans. The present study consisted of a representative sampling of sheep flocks from all parts of Norway. This is the first large survey of sheep flocks focusing on E. coli O26 in general, including results of STEC, aEPEC, and nonpathogenic isolates.

Sekse, C.; Sunde, M.; Lindstedt, B.-A.; Hopp, P.; Bruheim, T.; Cudjoe, K. S.; Kvitle, B.; Urdahl, A. M.

2011-01-01

202

Potentially human-pathogenic Escherichia coli O26 in Norwegian sheep flocks.  

PubMed

A national survey of Escherichia coli O26 in Norwegian sheep flocks was conducted, using fecal samples to determine the prevalence. In total, 491 flocks were tested, and E. coli O26 was detected in 17.9% of the flocks. One hundred forty-two E. coli O26 isolates were examined for flagellar antigens (H typing) and four virulence genes, including stx and eae, to identify possible Shiga toxin-producing E. coli (STEC) and enteropathogenic E. coli (EPEC). Most isolates (129 out of 142) were identified as E. coli O26:H11. They possessed eae and may have potential as human pathogens, although only a small fraction were identified as STEC O26:H11, giving a prevalence in sheep flocks of only 0.8%. Correspondingly, the sheep flock prevalence of atypical EPEC (aEPEC) O26:H11 was surprisingly high (15.9%). The genetic relationship between the E. coli O26:H11 isolates was investigated by pulsed-field gel electrophoresis (PFGE) and multilocus variable number tandem repeat analysis (MLVA), identifying 63 distinct PFGE profiles and 22 MLVA profiles. Although the MLVA protocol was less discriminatory than PFGE and a few cases of disagreement were observed, comparison by partition mapping showed an overall good accordance between the two methods. A close relationship between a few isolates of aEPEC O26:H11 and STEC O26:H11 was identified, but all the E. coli O26:H11 isolates should be considered potentially pathogenic to humans. The present study consisted of a representative sampling of sheep flocks from all parts of Norway. This is the first large survey of sheep flocks focusing on E. coli O26 in general, including results of STEC, aEPEC, and nonpathogenic isolates. PMID:21642413

Sekse, C; Sunde, M; Lindstedt, B-A; Hopp, P; Bruheim, T; Cudjoe, K S; Kvitle, B; Urdahl, A M

2011-07-01

203

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.

2010-01-01

204

Tetraphenylborate potentiates the respiratory inhibition by the dopaminergic neurotoxin MPP+ in both electron transport particles and intact mitochondria.  

PubMed

The cytotoxicity of 1-methyl-4-phenylpyridinium (MPP+) is believed to arise as a consequence of its time- and energy-dependent accumulation inside mitochondria, followed by inhibition of electron transport at Complex I of the respiratory chain. Consistent with our proposal that the accumulation of MPP+ represents a passive Nernstian transport into mitochondria in response to the transmembrane electrochemical potential gradient, tetraphenylborate (TPB-) was found to accelerate the onset of the respiratory inhibition by MPP+ on intact mitochondria. Moreover, the ultimate level of inhibition reached was unexpectedly also increased. The latter is now explained by our finding that TPB- elicits a 12-fold enhancement of MPP+ inhibition of respiration in electron transport particles. It is suggested that TPB- facilitates access of MPP+ to its intramembrane site of inhibitory action in Complex I. PMID:2786720

Sayre, L M; Wang, F; Hoppel, C L

1989-06-15

205

Experimental Study to Determine if Low-Pathogenicity and High-Pathogenicity Avian Influenza Viruses Can Be Present in Chicken Breast and Thigh Meat Following Intranasal Virus Inoculation  

Microsoft Academic Search

SUMMARY. Two low-pathogenicity (LP) and two high-pathogenicity (HP) avian influenza (AI) viruses were inoculated into chickens by the intranasal route to determine the presence of the AI virus in breast and thigh meat as well as any potential role that meat could fill as a transmission vehicle. The LPAI viruses caused localized virus infections in respiratory and gastrointestinal (GI) tracts.

David E. Swayne; Joan R. Beck

2005-01-01

206

Results of the Alexander Project: a continuing, multicenter study of the antimicrobial susceptibility of community-acquired lower respiratory tract bacterial pathogens.  

PubMed

In 1992, an ongoing, international multicenter study was established to investigate the antimicrobial susceptibility of community-acquired lower respiratory tract bacterial pathogens: the Alexander Project. Isolates cultured from patients living in geographically separated areas, ten in the European Union (EU) and five in the United States (US), were collected and tested using standard methods in a central laboratory. A total of 4,155 isolates of Haemophilus influenzae was collected during the period 1992-1994. beta-lactamase production was the principal mechanism of resistance observed with overall rates in the US (1992 = 26.3%; 1993 = 28.2%; and 1994 = 30.1%) generally twice those seen in the EU (1992 = 12.3%; 1993 = 14.4%; and 1994 = 15.5%). Chloramphenicol resistance was generally low except in Spanish centers where rates ranging from 4.0 to 15.9% were observed during the study period. One thousand one hundred ninety-three isolates of Moraxella catarrhalis were tested. beta-lactamase production was the only mechanism of resistance of any importance detected, with the vast majority of isolates producing the enzyme. Two thousand eight hundred twenty-nine isolates of Streptococcus pneumoniae were tested. French and Spanish centers provided isolates with the highest rates of either low-level (intermediate) or high-level penicillin resistance, which in 1994 ranged from 10.2 to 31.4% and 30.4 to 40.1% for each resistance category, respectively. With the exception of the fluoroquinolones, rates of resistance to other antimicrobials including the macrolides, doxycycline, chloramphenicol, and trimethoprim/sulfamethoxazole were high, generally, in centers with a high prevalence of penicillin resistance. However, in some centers (Toulouse, France and Genoa, Italy) this association was not complete for the macrolides. PMID:8937841

Grüneberg, R N; Felmingham, D

1996-08-01

207

Assessing pathogenicity of Gallibacterium anatis in a natural infection model: the respiratory and reproductive tracts of chickens are targets for bacterial colonization.  

PubMed

Two separate bird trials were performed to establish a reliable route of infection for Gallibacterium anatis in chickens, comparing intranasal (i.n.) and intravenous (i.v.) applications. Additionally, three mutually divergent isolates from three geographical locations, as shown by MALDI-TOF-MS and partial rpoB gene sequence analysis, were compared. In the first trial, birds were infected with one of the selected isolates by the i.v. or i.n. route. Subsequently, birds were killed 3, 12 and 24 h post infection following i.v. infection while at 3, 7 and 10 days post infection (dpi) in the case of i.n. infection along with birds of the control group. As a result, i.n. infection showed prominent and consistent bacterial tissue distribution in different organs persisting until 10 dpi, which was a striking contrast to the i.v. infection route. Likewise, histopathology revealed mild to severe tracheal lesions following i.n. infection. The second trial was set up to confirm both the achieved results and the robustness of i.n. infection but with an extended observation period, until 28 dpi In agreement with the preceding trial, identical results for bacteriological and histopathological examinations were obtained with persistency of bacteria until 28 dpi Comparing the three different isolates from Mexico, China and Austria, the Mexican isolate showed a somewhat higher pathogenicity than the other strains. Consequently, pathogenesis of G. anatis strains was studied in chickens elucidating i.n. infection as the most reliable route characterized by a long-lasting bacteraemia, targeting the respiratory and reproductive tract. PMID:24098932

Paudel, Surya; Alispahic, Merima; Liebhart, Dieter; Hess, Michael; Hess, Claudia

2013-12-01

208

Advances in and the potential of vaccines for respiratory syncytial virus.  

PubMed

Respiratory syncytial virus (RSV) is the leading cause of serious lower respiratory track illness causing bronchiolitis and some mortality in infants and the elderly. Despite decades of research there is no licensed RSV vaccine. To enable the development of RSV vaccines, several major obstacles must be overcome including immature and waning immunity to RSV infection, the capacity of RSV to evade immunity and the failure of RSV infection to induce robust enduring immunity. Since the failure of the formalin-inactivated RSV vaccine trial, more cautious and deliberate progress has been made toward RSV vaccine development using a variety of experimental approaches. The scientific rational and the state of development of these approaches are reviewed in this article. PMID:23964629

Jorquera, Patricia A; Oakley, Katie E; Tripp, Ralph A

2013-08-01

209

"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.

2012-01-01

210

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

PubMed

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. PMID:23722926

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

2014-07-01

211

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

Microsoft Academic Search

The purpose of this study was to assess the magnitude and direction of respiratory displacement of the ascending and descending\\u000a thoracic aorta during breathing maneuvers. In 11 healthy nonsmokers, dynamic magnetic resonance imaging was performed in transverse\\u000a orientation at the tracheal bifurcation during maximum expiration and inspiration as well as tidal breathing. The magnitude\\u000a and direction of aortic displacement was

Tim Frederik Weber; Ralf Tetzlaff; Fabian Rengier; Philipp Geisbüsch; Annette Kopp-Schneider; Dittmar Böckler; Monika Eichinger; Hans-Ulrich Kauczor; Hendrik von Tengg-Kobligk

2009-01-01

212

Potential role for imidazole in the rhythmic respiratory activity of the in vitro neonatal rat brainstem  

Microsoft Academic Search

We used the imidazole-binding agent, diethylpyrocarbonate (DEPC), to test the hypothesis that rhythmic respiratory activity of the in vitro neonatal rat brainstem-spinal cord preparation was functionally dependent on imidazole. Neural activity was recorded from spinal nerves (C1-C4) during superfusion with 95%O2\\/5%CO2 buffer at pH 7.3 and T=26°C. Superfusate containing DEPC (40 mM) caused cessation of rhythmic activity within minutes. In

William L Krause; Homayoun Kazemi; Melvin D Burton

1998-01-01

213

Respiratory Syncytial Virus (RSV) Infection Induces Cyclooxygenase 2: A Potential Target for RSV Therapy1  

Microsoft Academic Search

Cyclooxygenases (COXs) are rate-limiting enzymes that initiate the conversion of arachidonic acid to prostanoids. COX-2 is the inducible isoform that is up-regulated by proinflammatory agents, initiating many prostanoid-mediated pathological aspects of inflammation. The roles of cyclooxygenases and their products, PGs, have not been evaluated during respiratory syncytial virus (RSV) infection. In this study we demonstrate that COX-2 is induced by

Joann Y. Richardson; Martin G. Ottolini; Lioubov Pletneva; Marina Boukhvalova; Shuling Zhang; Stefanie N. Vogel; Gregory A. Prince; Jorge C. G. Blanco

214

Production of prodigiosin and chitinases by tropical Serratia marcescens strains with potential to control plant pathogens.  

PubMed

The potential of three Serratia marcescens strains (CFFSUR-B2, CFFSUR-B3 and CFFSUR-B4) isolated from tropical regions in Mexico to inhibit the mycelial growth and conidial germination of Colletotrichum gloeosporioides, causal agent of fruit anthracnose, was evaluated. The ability of these strains to produce prodigiosin and chitinases when cultivated in oil seed-based media (peanut, sesame, soybean and castor bean) and in Luria-Bertani medium was determined. All of the strains exhibited similar fungal antagonistic activities and inhibited myceliar growth by more than 40% while inhibiting conidial germination by 81-89% (P = 0.01). The highest level of prodigiosin (40 ?g/ml) was produced in the peanut-based medium while growth in soybean-based medium allowed the highest production of chitinases (56 units/ml), independent of the strain used. Strain CFFSUR-B2 grown in peanut medium was used to evaluate the effect of inoculum density and initial pH on metabolite production. The amount of prodigiosin produced increased with greater inoculum densities, with an initial density of 1 × 10(12) resulting in the highest production (60 ?g/ml). Prodigiosin production was not affected by pH. The strains studied have the advantage of being adapted to tropical climates and are able to produce chitinases in the absence of chitin induction in vitro. These characteristics suggest their potential as biocontrol agents for fungal pathogens in tropical regions of the world. PMID:22806790

Gutiérrez-Román, Martha Ingrid; Holguín-Meléndez, Francisco; Bello-Mendoza, Ricardo; Guillén-Navarro, Karina; Dunn, Michael F; Huerta-Palacios, Graciela

2012-01-01

215

Protective or pathogenic effects of vascular endothelial growth factor (VEGF) as potential biomarker in cerebral malaria.  

PubMed

Cerebral malaria (CM) is the major lethal complication of Plasmodium falciparum infection. It is characterized by persistent coma along with symmetrical motor signs. Several clinical, histopathological, and laboratory studies have suggested that cytoadherence of parasitized erythrocytes, neural injury by malarial toxin, and excessive inflammatory cytokine production are possible pathogenic mechanisms. Although the detailed pathophysiology of CM remains unsolved, it is thought that the binding of parasitized erythrocytes to the cerebral endothelia of microvessels, leading to their occlusion and the consequent angiogenic dysregulation play a key role in the disease pathogenesis. Recent evidences showed that vascular endothelial growth factor (VEGF) and its receptor-related molecules are over-expressed in the brain tissues of CM patients, as well as increased levels of VEGF are detectable in biologic samples from malaria patients. Whether the modulation of VEGF is causative agent of CM mortality or a specific phenotype of patients with susceptibility to fatal CM needs further evaluation. Currently, there is no biological test available to confirm the diagnosis of CM and its complications. It is hoped that development of biomarkers to identify patients and potential risk for adverse outcomes would greatly enhance better intervention and clinical management to improve the outcomes. We review and discuss here what it is currently known in regard to the role of VEGF in CM as well as VEGF as a potential biomarker. PMID:24601908

Canavese, Miriam; Spaccapelo, Roberta

2014-03-01

216

Cross-infection potential of crown rot pathogen ( Lasiodiplodia theobromae ) isolates and their management using potential native bioagents in banana  

Microsoft Academic Search

Crown rot infected banana samples collected from different regions of India revealed that the fungus Lasiodiplodia theobromae was the major pathogen responsible for crown rot and Colletotrichum musae and Fusarium spp. were the minor pathogens. The cross-inoculation experiment, conducted using five different virulent isolates of L. theobromae on five different commercial cultivars of banana, demonstrated that generally the isolates were

R. Thangavelu; G. Sangeetha; M. M. Mustaffa

2007-01-01

217

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.

2014-01-01

218

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

219

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 Central

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.

2014-01-01

220

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

Brown, H R

1990-01-01

221

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

222

Genome Sequence of Aureobasidium pullulans AY4, an Emerging Opportunistic Fungal Pathogen with Diverse Biotechnological Potential  

PubMed Central

Aureobasidium pullulans AY4 is an opportunistic pathogen that was isolated from the skin of an immunocompromised patient. We present here the draft genome of strain AY4, which reveals an abundance of genes relevant to bioindustrial applications, including biocontrol and biodegradation. Putative genes responsible for the pathogenicity of strain AY4 were also identified.

Bamadhaj, Hasima Mustafa; Gan, Han Ming; Rashid, Noor Aini Abdul

2012-01-01

223

Prevalence of potentially pathogenic enteric organisms in clinically healthy kittens in the UK.  

PubMed

Faecal samples were collected from 57 clinically healthy kittens presented for initial vaccination, in the UK. Routine bacteriological examination identified Salmonella species in one and Campylobacter species in five samples. Polymerase chain reaction (PCR) detected the presence of Campylobacter species in a further four samples. Routine parasitological examination revealed Toxocara species ova in nine (including four kittens stated to have been administered an anthelmintic) and Isospora species in four samples. No Giardia or Cryptosporidium species were detected by routine methods. A Giardia species enzyme-linked immunosorbent assay (ELISA) test kit designed for use in cats was positive in three kittens. A similar test kit designed for use in humans was negative in all samples and produced negative results even when known positive samples were tested. Potentially pathogenic enteric organisms were detected in 19 kittens by routine methods and 26 (prevalence 45%) by all methods. The high prevalence in asymptomatic kittens highlights the possibility that the detection of these organisms in kittens with gastrointestinal disease may be an incidental finding. PMID:19249233

Gow, Adam G; Gow, Deborah J; Hall, Edward J; Langton, Debra; Clarke, Chris; Papasouliotis, Kostas

2009-08-01

224

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.

Kjaer, Erik Dahl; McKinney, Lea Vig; Nielsen, Lene Rostgaard; Hansen, Lars N?rgaard; Hansen, Jon Kehlet

2012-01-01

225

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.

Naz, Rabia; Bano, Asghari

2012-01-01

226

Years of potential life lost for six major enteric pathogens, Germany, 2004-2008.  

PubMed

In industrialized countries, acute infectious enteric diseases are usually mild, but they can also cause death. They do so, however, at different ages. Using 2004-2008 German notification data, we computed and compared crude and premature mortality [three different measures of years of potential life lost (YPLL)] of illnesses caused by Campylobacter spp., Listeria monocytogenes, norovirus, rotavirus, non-typhoidal Salmonella spp., and Shiga toxin-producing E. coli (STEC). Among ~1.5 million notified illnesses, those caused by norovirus were the most frequent. The highest annual mortality was registered for salmonellosis (0.55/1 000 000 population), but listeriosis accounted for the highest number of YPLL (n=4245). Disregarding death at advanced age (i.e. >70 years), STEC illness (n=757) and rotavirus gastroenteritis (n=648) ranked second and third, following listeriosis (n=2306). Routine surveillance captures only a fraction of all incident cases and deaths, under-ascertaining the true burden of disease. Weighting death by age permits a different view on the disease burden individual enteric pathogens cause and particularly underscores the public health importance of listeriosis prevention. PMID:22813426

Werber, D; Hille, K; Frank, C; Dehnert, M; Altmann, D; Müller-Nordhorn, J; Koch, J; Stark, K

2013-05-01

227

Overwintering of Culex mosquitoes in Sweden and their potential as reservoirs of human pathogens.  

PubMed

1. Culex pipiens L. and Cx torrentium Martini are suspected enzootic vectors in Sweden of Sindbis virus causing Ockelbo disease in man. To estimate their potential as virus reservoirs over the winter, mosquitoes were collected from August to May from a cellar in a rural area, central Sweden. The mosquitoes were dissected and examined for blood content, gonotrophic stage, parity and insemination, and tested for fructose. 2. Cx pipiens, Cx torrentium and Cx territans Walker constituted 94% of 887 females caught. A few Culiseta annulata (Schrank), Cs. alaskaensis (Ludlow) and An. maculipennis Meigen s.l. were also collected. 3. Data suggested that all blood-fed, parous Culex females disappeared during the winter and that only non-bloodfed, nulliparous females survived. 4. Fructose, detected in some of these females, and other plant sugars may be the main energy sources for winter survival. 5. Unless transovarially or venerally infected, Culex females are presumably of no or very limited importance in rural, central Sweden as winter reservoirs for blood-borne pathogens of vertebrates. PMID:2856507

Jaenson, T G

1987-04-01

228

Antibacterial potential of silver nanoparticles against isolated urinary tract infectious bacterial pathogens  

NASA Astrophysics Data System (ADS)

The silver nanoparticles were synthesized by chemical reduction method and the nanoparticles were characterized using ultraviolet-visible (UV-Vis) absorption spectroscopy and X-ray diffraction (XRD) studies. The synthesized silver nanoparticles were investigated to evaluate the antibacterial activity against urinary tract infectious (UTIs) bacterial pathogens. Thirty-two bacteria were isolated from mid urine samples of 25 male and 25 female patients from Thondi, Ramanathapuram District, Tamil Nadu, India and identified by conventional methods. Escherichia coli was predominant (47%) followed by Pseudomonas aeruginosa (22%), Klebsiella pneumoniae (19%), Enterobacter sp. (6%), Proteus morganii (3%) and Staphylococcus aureus (3%). The antibacterial activity of silver nanoparticles was evaluated by disc diffusion assay. P. aeruginosa showed maximum sensitivity (11 ± 0.58 mm) followed by Enterobacter sp. (8 ± 0.49 mm) at a concentration of 20 ?g disc-1 and the sensitivity was highly comparable with the positive control kanamycin and tetracycline. K. pneumoniae, E. coli, P. morganii and S. aureus showed no sensitivity against all the tested concentrations of silver nanoparticles. The results provided evidence that, the silver nanoparticles might indeed be the potential sources to treat urinary tract infections caused by P. aeruginosa and Enterobacter sp.

Jacob Inbaneson, Samuel; Ravikumar, Sundaram; Manikandan, Nachiappan

2011-12-01

229

Respiratory symptoms among glass bottle makers exposed to stannic chloride solution and other potentially hazardous substances  

SciTech Connect

Concern about upper respiratory tract irritation and other symptoms among workers at a glass bottle manufacturing plant led to an epidemiologic and an industrial hygiene survey. Questionnaire responses from 35 hot end and 53 cold end workers indicated that the incidence of wheezing, chest pain, dyspnea on exertion, and cough was significantly elevated among hot end workers. Among both smokers and nonsmokers, hot end workers reported higher, but not significantly higher, rates of wheezing and chest pain. Among smokers, hot end workers reported significantly higher rates of dyspnea on exertion and cough than did cold end workers. Data suggest that reported exposure to stannic chloride solution likely caused these symptoms. The industrial hygiene survey, conducted when stannic chloride use had been reduced, cleaning had been done, and ventilation improved, focused on measuring air contaminants that might possibly cause symptoms. Levels of hydrogen chloride, which apparently was formed by the combination of stannic chloride and water in the presence of heat, were elevated. The finding of increased prevalence of respiratory symptoms among hot end workers was consistent with this exposure. Recommendations were made to reduce hazardous exposures at this plant. Individuals responsible for occupational health should be aware that relatively benign substances, such as stannic chloride and water, can combine spontaneously to form hazardous substances.

Levy, B.S.; Davis, F.; Johnson, B.

1985-04-01

230

Antimicrobial resistance among respiratory pathogens in Spain: latest data and changes over 11 years (1996-1997 to 2006-2007).  

PubMed

A nationwide multicenter susceptibility surveillance study (Susceptibility to the Antimicrobials Used in the Community in España [SAUCE] project), SAUCE-4, including 2,559 Streptococcus pneumoniae, 2,287 Streptococcus pyogenes, and 2,736 Haemophilus influenzae isolates was carried out from May 2006 to June 2007 in 34 Spanish hospitals. Then, the results from SAUCE-4 were compared to those from all three previous SAUCE studies carried out in 1996-1997, 1998-1999, and 2001-2002 to assess the temporal trends in resistance and the phenotypes of resistance over the 11-year period. In SAUCE-4, on the basis of the CLSI breakpoints, penicillin (parenteral, nonmeningitis breakpoint) and cefotaxime were the antimicrobials that were the most active against S. pneumoniae (99.8% and 99.6%, respectively). Only 0.9% of isolates had a penicillin MIC of > or = 2 microg/ml. In S. pyogenes, nonsusceptibility to erythromycin was observed in 19.4% of isolates. Among the H. influenzae isolates, a beta-lactamase-positive prevalence of 15.7% was found. A statistically significant temporal decreasing trend over the 11-year period was observed for nonsusceptibility (from 60.0% to 22.9%) and resistance (from 36.5% to 0.9%) to penicillin and for the proportion of erythromycin-resistant isolates of S. pneumoniae of the macrolide-lincosamide-streptogramin B (MLS(B)) phenotype (from 98.4% to 81.3%). A similar trend was observed for the prevalence of ampicillin resistance (from 37.6% to 16.1%), beta-lactamase production (from 25.7% to 15.7%), and beta-lactamase-negative ampicillin resistance (BLNAR) in H. influenzae (from 13.5% to 0.7%). Among erythromycin-resistant isolates of S. pyogenes, a significant increasing trend in the prevalence of MLS(B) was observed (from 7.0% to 35.5%). SAUCE-4 confirms a generalized decline in the resistance of the main respiratory pathogens to the antimicrobials as well as a shift in their resistance phenotypes. PMID:20439616

Pérez-Trallero, Emilio; Martín-Herrero, Jose E; Mazón, Ana; García-Delafuente, Celia; Robles, Purificación; Iriarte, Victor; Dal-Ré, Rafael; García-de-Lomas, Juan

2010-07-01

231

Antimicrobial Resistance among Respiratory Pathogens in Spain: Latest Data and Changes over 11 Years (1996-1997 to 2006-2007)?  

PubMed Central

A nationwide multicenter susceptibility surveillance study (Susceptibility to the Antimicrobials Used in the Community in España [SAUCE] project), SAUCE-4, including 2,559 Streptococcus pneumoniae, 2,287 Streptococcus pyogenes, and 2,736 Haemophilus influenzae isolates was carried out from May 2006 to June 2007 in 34 Spanish hospitals. Then, the results from SAUCE-4 were compared to those from all three previous SAUCE studies carried out in 1996-1997, 1998-1999, and 2001-2002 to assess the temporal trends in resistance and the phenotypes of resistance over the 11-year period. In SAUCE-4, on the basis of the CLSI breakpoints, penicillin (parenteral, nonmeningitis breakpoint) and cefotaxime were the antimicrobials that were the most active against S. pneumoniae (99.8% and 99.6%, respectively). Only 0.9% of isolates had a penicillin MIC of ?2 ?g/ml. In S. pyogenes, nonsusceptibility to erythromycin was observed in 19.4% of isolates. Among the H. influenzae isolates, a ?-lactamase-positive prevalence of 15.7% was found. A statistically significant temporal decreasing trend over the 11-year period was observed for nonsusceptibility (from 60.0% to 22.9%) and resistance (from 36.5% to 0.9%) to penicillin and for the proportion of erythromycin-resistant isolates of S. pneumoniae of the macrolide-lincosamide-streptogramin B (MLSB) phenotype (from 98.4% to 81.3%). A similar trend was observed for the prevalence of ampicillin resistance (from 37.6% to 16.1%), ?-lactamase production (from 25.7% to 15.7%), and ?-lactamase-negative ampicillin resistance (BLNAR) in H. influenzae (from 13.5% to 0.7%). Among erythromycin-resistant isolates of S. pyogenes, a significant increasing trend in the prevalence of MLSB was observed (from 7.0% to 35.5%). SAUCE-4 confirms a generalized decline in the resistance of the main respiratory pathogens to the antimicrobials as well as a shift in their resistance phenotypes.

Perez-Trallero, Emilio; Martin-Herrero, Jose E.; Mazon, Ana; Garcia-Delafuente, Celia; Robles, Purificacion; Iriarte, Victor; Dal-Re, Rafael; Garcia-de-Lomas, Juan

2010-01-01

232

Epidemiology of nasopharyngeal carriage of respiratory bacterial pathogens in children and adults: cross-sectional surveys in a population with high rates of pneumococcal disease  

PubMed Central

Background To determine the prevalence of carriage of respiratory bacterial pathogens, and the risk factors for and serotype distribution of pneumococcal carriage in an Australian Aboriginal population. Methods Surveys of nasopharyngeal carriage of Streptococcus pneumoniae, non-typeable Haemophilus influenzae, and Moraxella catarrhalis were conducted among adults (?16 years) and children (2 to 15 years) in four rural communities in 2002 and 2004. Infant seven-valent pneumococcal conjugate vaccine (7PCV) with booster 23-valent pneumococcal polysaccharide vaccine was introduced in 2001. Standard microbiological methods were used. Results At the time of the 2002 survey, 94% of eligible children had received catch-up pneumococcal vaccination. 324 adults (538 examinations) and 218 children (350 examinations) were enrolled. Pneumococcal carriage prevalence was 26% (95% CI, 22-30) among adults and 67% (95% CI, 62-72) among children. Carriage of non-typeable H. influenzae among adults and children was 23% (95% CI, 19-27) and 57% (95% CI, 52-63) respectively and for M. catarrhalis, 17% (95% CI, 14-21) and 74% (95% CI, 69-78) respectively. Adult pneumococcal carriage was associated with increasing age (p = 0.0005 test of trend), concurrent carriage of non-typeable H. influenzae (Odds ratio [OR] 6.74; 95% CI, 4.06-11.2) or M. catarrhalis (OR 3.27; 95% CI, 1.97-5.45), male sex (OR 2.21; 95% CI, 1.31-3.73), rhinorrhoea (OR 1.66; 95% CI, 1.05-2.64), and frequent exposure to outside fires (OR 6.89; 95% CI, 1.87-25.4). Among children, pneumococcal carriage was associated with decreasing age (p < 0.0001 test of trend), and carriage of non-typeable H. influenzae (OR 9.34; 95% CI, 4.71-18.5) or M. catarrhalis (OR 2.67; 95% CI, 1.34-5.33). Excluding an outbreak of serotype 1 in children, the percentages of serotypes included in 7, 10, and 13PCV were 23%, 23%, and 29% (adults) and 22%, 24%, and 40% (2-15 years). Dominance of serotype 16F, and persistent 19F and 6B carriage three years after initiation of 7PCV is noteworthy. Conclusions Population-based carriage of S. pneumoniae, non-typeable H. influenzae, and M. catarrhalis was high in this Australian Aboriginal population. Reducing smoke exposure may reduce pneumococcal carriage. The indirect effects of 10 or 13PCV, above those of 7PCV, among adults in this population may be limited.

2010-01-01

233

Arcobacter: comparison of isolation methods, diversity, and potential pathogenic factors in commercially retailed chicken breast meat from costa rica.  

PubMed

Arcobacter species have been recognized as potential food- and waterborne pathogens. The lack of standardized isolation methods and the relatively scarce knowledge about their prevalence and distribution as emerging pathogens are due to the limitations in their detection and identification. This study aimed to determine the presence and the identification of Arcobacter in chicken breast samples commercially retailed in San José, Costa Rica, as well as to describe the adherence and invasive potential of the strains to human cells (HEp-2). Fifty chicken breast samples were collected from retail markets in the metropolitan area of the country. Six different isolation methodologies were applied for the isolation of Arcobacter. Isolation strategies consisted of combinations of enrichments in de Boer or Houf selective broths and subsequent isolation in blood agar (directly or with a previous passive membrane filtration step) or Arcobacter selective agar. Suspicious colonies were identified with a genus-specific PCR, whereas species-level identification was achieved with a multiplex PCR. The overall isolation frequency of Arcobacter was 56%. From the isolation strategies, the combination of enrichment in Houf selective broth followed by filtration on blood agar showed the best performance, with a sensitivity of 89% and a specificity of 84%. A total of 46 isolates were confirmed as Arcobacter with the genus-specific PCR, from which 27 (59%) corresponded to Arcobacter butzleri, 9 (19%) to Arcobacter cryaerophilus, and 10 (22%) were not identified with this multiplex PCR. Regarding the potential pathogenicity, 75% of the isolates presented adherence to HEp-2 cells, while only 22% were invasive to that cell line. All invasive strains were A. butzleri or nonidentified strains. The results show the presence of potentially pathogenic Arcobacter in poultry and recognize the importance it should receive as a potential foodborne pathogen from public health authorities. PMID:24853508

Fallas-Padilla, Karolina L; Rodríguez-Rodríguez, Carlos E; Jaramillo, Heriberto Fernández; Echandi, María Laura Arias

2014-06-01

234

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.

Belmonte, Rodrigo; Lobach, Lars; Christie, James; van den Ackerveken, Guido; Bottin, Arnaud; Bulone, Vincent; Diaz-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

235

Glycans in pathogenic bacteria--potential for targeted covalent therapeutics and imaging agents.  

PubMed

A substantial obstacle to the existing treatment of bacterial diseases is the lack of specific probes that can be used to diagnose and treat pathogenic bacteria in a selective manner while leaving the microbiome largely intact. To tackle this problem, there is an urgent need to develop pathogen-specific therapeutics and diagnostics. Here, we describe recent evidence that indicates distinctive glycans found exclusively on pathogenic bacteria could form the basis of targeted therapeutic and diagnostic strategies. In particular, we highlight the use of metabolic oligosaccharide engineering to covalently deliver therapeutics and imaging agents to bacterial glycans. PMID:24647371

Tra, Van N; Dube, Danielle H

2014-05-11

236

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

237

Secretome analysis identifies potential virulence factors of Diplodia corticola, a fungal pathogen involved in cork oak (Quercus suber) decline.  

PubMed

The characterisation of the secretome of phytopathogenic fungi may contribute to elucidate the molecular mechanisms of pathogenesis. This is particularly relevant for Diplodia corticola, a fungal plant pathogen belonging to the family Botryosphaeriaceae, whose genome remains unsequenced. This phytopathogenic fungus is recognised as one of the most important pathogens of cork oak, being related to the decline of cork oak forests in the Iberian Peninsula. Unfortunately, secretome analysis of filamentous fungi is limited by the low protein concentration and by the presence of many interfering substances, such as polysaccharides, which affect the separation and analysis by 1D and 2D gel electrophoresis. We compared six protein extraction protocols concerning their suitability for further application with proteomic workflows. The protocols involving protein precipitation were the most efficient, with emphasis on TCA-acetone protocol, allowing us to identify the most abundant proteins on the secretome of this plant pathogen. Approximately 60 % of the spots detected were identified, all corresponding to extracellular proteins. Most proteins identified were carbohydrate degrading enzymes and proteases that may be related to D. corticola pathogenicity. Although the secretome was assessed in a noninfection environment, potential virulence factors such as the putative glucan-?-glucosidase, neuraminidase, and the putative ferulic acid esterase were identified. The data obtained forms a useful basis for a deeper understanding of the pathogenicity and infection biology of D. corticola. Moreover, it will contribute to the development of proteomics studies on other members of the Botryosphaeriaceae. PMID:24863480

Fernandes, Isabel; Alves, Artur; Correia, António; Devreese, Bart; Esteves, Ana Cristina

2014-01-01

238

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

239

Reptiles as potential vectors and hosts of the amphibian pathogen Batrachochytrium dendrobatidis in Panama.  

PubMed

Chytridiomycosis, the disease caused by Batrachochytrium dendrobatidis, is considered to be a disease exclusively of amphibians. However, B. dendrobatidis may also be capable of persisting in the environment, and non-amphibian vectors or hosts may contribute to disease transmission. Reptiles living in close proximity to amphibians and sharing similar ecological traits could serve as vectors or reservoir hosts for B. dendrobatidis, harbouring the organism on their skin without succumbing to disease. We surveyed for the presence of B. dendrobatidis DNA among 211 lizards and 8 snakes at 8 sites at varying elevations in Panama where the syntopic amphibians were at pre-epizootic, epizootic or post-epizootic stages of chytridiomycosis. Detection of B. dendrobatidis DNA was done using qPCR analysis. Evidence of the amphibian pathogen was present at varying intensities in 29 of 79 examined Anolis humilis lizards (32%) and 9 of 101 A. lionotus lizards (9%), and in one individual each of the snakes Pliocercus euryzonus, Imantodes cenchoa, and Nothopsis rugosus. In general, B. dendrobatidis DNA prevalence among reptiles was positively correlated with the infection prevalence among co-occurring anuran amphibians at any particular site (r = 0.88, p = 0.004). These reptiles, therefore, may likely be vectors or reservoir hosts for B. dendrobatidis and could serve as disease transmission agents. Although there is no evidence of B. dendrobatidis disease-induced declines in reptiles, cases of coincidence of reptile and amphibian declines suggest this potentiality. Our study is the first to provide evidence of non-amphibian carriers for B. dendrobatidis in a natural Neotropical environment. PMID:22303629

Kilburn, Vanessa L; Ibáñez, Roberto; Green, David M

2011-12-01

240

Potentially Pathogenic Airway Bacteria and Neutrophilic Inflammation in Treatment Resistant Severe Asthma  

PubMed Central

Background Molecular microbiological analysis of airway samples in asthma has demonstrated an altered microbiome in comparison to healthy controls. Such changes may have relevance to treatment-resistant severe asthma, particularly those with neutrophilic airway inflammation, as bacteria might be anticipated to activate the innate immune response, a process that is poorly steroid responsive. An understanding of the relationship between airway bacterial presence and dominance in severe asthma may help direct alternative treatment approaches. Objective We aimed to use a culture independent analysis strategy to describe the presence, dominance and abundance of bacterial taxa in induced sputum from treatment resistant severe asthmatics and correlate findings with clinical characteristics and airway inflammatory markers. Methods Induced sputum was obtained from 28 stable treatment-resistant severe asthmatics. The samples were divided for supernatant IL-8 measurement, cytospin preparation for differential cell count and Terminal Restriction Fragment Length Polymorphism (T-RFLP) profiling for bacterial community analysis. Results In 17/28 patients, the dominant species within the airway bacterial community was Moraxella catarrhalis or a member of the Haemophilus or Streptococcus genera. Colonisation with these species was associated with longer asthma disease duration (mean (SD) 31.8 years (16.7) vs 15.6 years (8.0), p?=?0.008), worse post-bronchodilator percent predicted FEV1 (68.0% (24.0) vs 85.5% (19.7), p?=?0.025) and higher sputum neutrophil differential cell counts (median (IQR) 80% (67–83) vs 43% (29–67), p?=?0.001). Total abundance of these organisms significantly and positively correlated with sputum IL-8 concentration and neutrophil count. Conclusions Airway colonisation with potentially pathogenic micro-organisms in asthma is associated with more severe airways obstruction and neutrophilic airway inflammation. This altered colonisation may have a role in the development of an asthma phenotype that responds less well to current asthma therapies.

Grainge, Christopher; Rogers, Geraint B.; Kehagia, Valia; Lau, Laurie; Carroll, Mary P.; Bruce, Kenneth D.; Howarth, Peter H.

2014-01-01

241

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

242

Feline respiratory disease complex.  

PubMed

Feline respiratory disease complex (FRDC) refers to the characteristic acute presentation of a contagious respiratory or ocular disease caused by one or multiple pathogens. Environmental and host factors impact the transmission, clinical presentation, preventive strategy, and treatment of affected cats. The FRDC is especially problematic in settings where large numbers of cats cohabit, including animal shelters, catteries, and semi-feral colonies. Although elimination of FRDC is an unrealistic goal, improved understanding can lead to strategies to minimize disease impact. PMID:22041216

Cohn, Leah A

2011-11-01

243

Propellant-driven aerosols of functional proteins as potential therapeutic agents in the respiratory tract.  

PubMed

Aerosols of respirable-sized particles of functional proteins were delivered by volatile propellant from metered-dose aerosol canisters. The enzyme alkaline-phosphatase and a monoclonal antibody were lyophilized with surfactant and suspended in the aerosol propellant dimethylether. As much as 20 micrograms of functional protein, assessed by enzyme function or antibody binding activity, was delivered per 40 microliters of released propellant. Up to 25% of the protein was of respirable size (< or = 4 microns mass median aerodynamic diameter) when aerosolized proteins were sampled with a Casella cyclone. Respirable particles were derived from visible surfactant/protein complexes suspended in the liquified propellant and from propellant-soluble, nonsedimentable, surfactant/protein molecules that are probably reverse micelles. 10-14 days of propellant exposure in dimethylether increased protein solubility in the propellant, increased the total protein aerosolized and maintained or increased the quantity of respirable-sized protein molecules, as compared to the day aerosol vials were charged with propellant. Scanning electron microscopic studies of the respirable-sized protein/surfactant particles showed that they ranged in size from 0.07 to 3.25 microns in diameter, and they appeared to be chain aggregates of spherical subunits, 0.11 to 0.93 microns in diameter. This structural motif was common to both proteins. The possibility of delivering immunizing antigens, cytokines, passive antibodies and other therapeutic proteins to the respiratory tract using propellant-driven aerosols is discussed. PMID:7852055

Brown, A R; Slusser, J G

1994-01-01

244

Pathogen-pathogen interaction  

PubMed Central

There is growing awareness of the health implications of the fact that infectious agents often do not act independently; rather their disease potential is mediated in diverse and significant ways by their relationships with other pathogens. Pathogen-pathogen interaction (PPI), for example, impacts various virulence factors in human infection. Although still in its infancy, the study of PPI, a form of epidemiological synergism, is emerging as an important arena of new research and new understanding in health and clinical care. The aims of this paper are to: (1) draw attention to the role of PPI in human disease patterns; (2) present the syndemics model as a biosocial approach for examining the nature, pathways, contexts, and health implications of PPI and (3) suggest the utility of this approach to PPI. Toward these ends, this paper (a) reviews three case examples of alternative PPIs, (b) describes the development and key concepts and components of the syndemics model with specific reference to interacting infectious agents, (c) contextualizes this discussion with a brief review of broader syndemics disease processes (not necessarily involving infections disease) and (d) comments on the research, treatment and prevention implications of syndemic interaction among pathogens.

2010-01-01

245

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.

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

2014-01-01

246

Ralstonia solanacearum strains from Martinique (French West Indies) exhibiting a new pathogenic potential.  

PubMed

We investigated a destructive pathogenic variant of the plant pathogen Ralstonia solanacearum that was consistently isolated in Martinique (French West Indies). Since the 1960s, bacterial wilt of solanaceous crops in Martinique has been caused primarily by strains of R. solanacearum that belong to either phylotype I or phylotype II. Since 1999, anthurium shade houses have been dramatically affected by uncharacterized phylotype II strains that also affected a wide range of species, such as Heliconia caribea, cucurbitaceous crops, and weeds. From 1989 to 2003, a total of 224 R. solanacearum isolates were collected and compared to 6 strains isolated in Martinique in the 1980s. The genetic diversity and phylogenetic position of selected strains from Martinique were assessed (multiplex PCRs, mutS and egl DNA sequence analysis) and compared to the genetic diversity and phylogenetic position of 32 reference strains covering the known diversity within the R. solanacearum species complex. Twenty-four representative isolates were tested for pathogenicity to Musa species (banana) and tomato, eggplant, and sweet pepper. Based upon both PCR and sequence analysis, 119 Martinique isolates from anthurium, members of the family Cucurbitaceae, Heliconia, and tomato, were determined to belong to a group termed phylotype II/sequevar 4 (II/4). While these strains cluster with the Moko disease-causing strains, they were not pathogenic to banana (NPB). The strains belonging to phylotype II/4NPB were highly pathogenic to tomato, eggplant, and pepper, were able to wilt the resistant tomato variety Hawaii7996, and may latently infect cooking banana. Phylotype II/4NPB constitutes a new pathogenic variant of R. solanacearum that has recently appeared in Martinique and may be latently prevalent throughout Caribbean and Central/South America. PMID:17720825

Wicker, Emmanuel; Grassart, Laurence; Coranson-Beaudu, Régine; Mian, Danièle; Guilbaud, Caroline; Fegan, Mark; Prior, Philippe

2007-11-01

247

Occurrence of potentially pathogenic Vibrio species in raw, processed, and ready-to-eat seafood and seafood products  

Microsoft Academic Search

This study investigated the occurrence (by means of the presence-absence test) and level (by means of a plate count technique) of selected potentially pathogenic Vibrio species in processed and ready-to-eat seafood, and some raw seafood normally used as raw materials or ingredients in these products, that were commercially available in Chiang Mai, Thailand. The level of Vibrio in raw seafood

Thararat Chitov; Sutipong Wongdao

248

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.

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

249

Chemosensory TRP channels in the respiratory tract: role in toxic lung injury and potential as "sweet spots" for targeted therapies.  

PubMed

Acute toxic lung injury by reactive inhalational compounds is an important and still unresolved medical problem. Hazardous gases or vapors, e. g. chlorine, phosgene, sulfur mustard or methyl isocyanate, are released during occupational accidents or combustion processes and also represent a potential threat in terroristic scenarios. According to their broad-range chemical reactivity, the mechanism of lung injury evoked by these agents has long been described as rather unspecific. Consequently, therapeutic options are still restricted to symptomatic treatment. However, in recent years, ion channels of the transient receptor potential (TRP) family have been identified to act as specific sensor molecules expressed in the respiratory tract and to engage defined signaling pathways upon inhalational exposure to toxic challenges. These pulmonary receptor molecules have been primarily characterized in sensory neurons of the lung. However, chemosensory molecules are also expressed in non-neuronal cells, e.g. in the lung epithelium as well as in the pulmonary vasculature. Thus, activation of respiratory chemosensors by toxic inhalants promotes a complex signaling network directly or indirectly regulating pulmonary blood flow, the integrity of the epithelial lining, and the mucociliary clearance of the bronchial system. This review gives a synopsis on reactive lung-toxic agents and their specific target molecules in the lung and summarizes the current knowledge about the pathophysiological role of chemosensory signaling in neuronal and non-neuronal cells in toxic lung injury. Finally, we describe possible future strategies for a causal, specifically tailored treatment option based on the mechanistic understanding of molecular events ensuing inhalation of lung-toxic agents. PMID:23532495

Büch, Thomas; Schäfer, Eva; Steinritz, Dirk; Dietrich, Alexander; Gudermann, Thomas

2013-01-01

250

Ixodes ricinus: the potential of two-dimensional gel electrophoresis as a tool for studying host-vector-pathogen interactions.  

PubMed

Ixodes ricinus is a three-host tick, with three active instars. For moulting to occur the tick has to find a host where it can take a blood meal. Throughout feeding I. ricinus can be infected or infect the host with different pathogens, e.g., Tick-Borne Encephalitis virus or Borrelia burgdorferi. The host-vector-pathogen interaction is very complex, making a detailed study difficult. Here we analyse the potential of two-dimensional gel electrophoresis (2DE) to study the host-vector-pathogen interaction. We examined 20 nymphs, which as larvae parasitised either mouse or hen. After moulting, they were kept alive for up to 30 weeks, to analyse whether tick ageing influenced host determination, and for comparison of the 2D-gels. Even though the number of proteins in the gel decreased during ageing, some proteins of the host determination persisted for all 30 weeks. We also discovered persisting proteins in relation to nymphs. These findings showed that 2DE is suitable as a tool for studying host-vector-pathogen interactions. PMID:16904668

Vennestrøm, J; Jensen, P M

2007-01-01

251

Potentiation of pathogen-specific defense mechanisms in Arabidopsis by -aminobutyric acid  

Microsoft Academic Search

The nonprotein amino acids -aminobutyric acid (GABA) and -aminobutyric acid (BABA) have known biological effects in animals and plants. Their mode of action has been the object of thorough research in animals but remains unclear in plants. Our objective was to study the mode of action of BABA in the protection of Arabidopis plants against virulent pathogens. BABA protected Arabidopsis

Laurent Zimmerli; Gabor Jakab; Jean-Pierre Métraux; Brigitte Mauch-Mani

2000-01-01

252

In Vitro Antimicrobial Potential of the Lichen Parmotrema sp. Extracts against Various Pathogens.  

PubMed

Objective(s): The ongoing increasing antibiotic resistance is one of the biggest challenges faced by global public health. The perennial need for new antimicrobials against a background of increasing antibiotic resistance in pathogenic and opportunistic microorganisms obliges the scientific community to constantly develop new drugs and antimicrobial agents. Lichens are known prolific sources of natural antimicrobial drugs and biologically active natural products. This study was aimed to explore in vitro antimicrobial activity of lichen Parmotrema sp. Material and Methods: The methanol and aqueous extracts of lichen Parmotrema sp. was extracted using Soxhlet extractor. Antibiotic assessment of methanol and aqueous extracts was done against eight bacterial (Escherichia coli, Staphylococcus aureus, Proteus mirabilis, Salmonella sp., Shigella sp., Enterococci faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae,) clinical pathogens and five plant pathogenic fungal strains (Aspergillus terreus strain JAS1, Scedosporium sp. JAS1, Ganoderma sp. JAS4, Candida tropicalis and Fusarium sp.) by Kirby-Bauer method. Results: The methanol lichen Parmotrema sp. extract inhibited all the test organisms. The highest antibacterial activity was found against Pseudomonas aeruginosa and Staphylococcus aureus. The weakest activity was manifested in Salmonella sp. and Scedosporium sp. JAS1. Strong antifungal effect was found against Ganoderma sp. JAS4 and Fusarium sp. The aqueous lichen Parmotrema sp. extract revealed neither antibacterial nor antifungal activity. Conclusion: The present study shows that tested lichen Parmotrema sp. extracts demonstrated a strong antimicrobial effect. That suggests the active components from methanol extracts of the investigated lichen Parmotrema sp. can be used as natural antimicrobial agent against pathogens. PMID:23997920

Chauhan, Ritika; Abraham, Jayanthi

2013-07-01

253

In Vitro Antimicrobial Potential of the Lichen Parmotrema sp. Extracts against Various Pathogens  

PubMed Central

Objective(s): The ongoing increasing antibiotic resistance is one of the biggest challenges faced by global public health. The perennial need for new antimicrobials against a background of increasing antibiotic resistance in pathogenic and opportunistic microorganisms obliges the scientific community to constantly develop new drugs and antimicrobial agents. Lichens are known prolific sources of natural antimicrobial drugs and biologically active natural products. This study was aimed to explore in vitro antimicrobial activity of lichen Parmotrema sp. Material and Methods: The methanol and aqueous extracts of lichen Parmotrema sp. was extracted using Soxhlet extractor. Antibiotic assessment of methanol and aqueous extracts was done against eight bacterial (Escherichia coli, Staphylococcus aureus, Proteus mirabilis, Salmonella sp., Shigella sp., Enterococci faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae,) clinical pathogens and five plant pathogenic fungal strains (Aspergillus terreus strain JAS1, Scedosporium sp. JAS1, Ganoderma sp. JAS4, Candida tropicalis and Fusarium sp.) by Kirby-Bauer method. Results: The methanol lichen Parmotrema sp. extract inhibited all the test organisms. The highest antibacterial activity was found against Pseudomonas aeruginosa and Staphylococcus aureus. The weakest activity was manifested in Salmonella sp. and Scedosporium sp. JAS1. Strong antifungal effect was found against Ganoderma sp. JAS4 and Fusarium sp. The aqueous lichen Parmotrema sp. extract revealed neither antibacterial nor antifungal activity. Conclusion: The present study shows that tested lichen Parmotrema sp. extracts demonstrated a strong antimicrobial effect. That suggests the active components from methanol extracts of the investigated lichen Parmotrema sp. can be used as natural antimicrobial agent against pathogens.

Chauhan, Ritika; Abraham, Jayanthi

2013-01-01

254

The poultry red mite ( Dermanyssus gallinae ): a potential vector of pathogenic agents  

Microsoft Academic Search

\\u000a The poultry red mite, D. gallinae has been involved in the transmission of many pathogenic agents, responsible for serious diseases both in animals and humans.\\u000a Nowadays, few effective methods are available to control the ectoparasite in poultry farms. Consequently, this is an emerging\\u000a problem which must be taken into account to maintain good health in commercial egg production. This paper

Claire Valiente Moro; Carlos J. De Luna; Alexander Tod; Jonathan H. Guy; Olivier A. E. Sparagano; Lionel Zenner

255

The poultry red mite ( Dermanyssus gallinae ): a potential vector of pathogenic agents  

Microsoft Academic Search

The poultry red mite, D. gallinae has been involved in the transmission of many pathogenic agents, responsible for serious diseases both in animals and humans.\\u000a Nowadays, few effective methods are available to control the ectoparasite in poultry farms. Consequently, this is an emerging\\u000a problem which must be taken into account to maintain good health in commercial egg production. This paper

Claire Valiente Moro; Carlos J. De Luna; Alexander Tod; Jonathan H. Guy; Olivier A. E. Sparagano; Lionel Zenner

2009-01-01

256

Potential Role of Pathogen Signaling in Multitrophic Plant-Microbe Interactions Involved in Disease Protection  

PubMed Central

Multitrophic interactions mediate the ability of fungal pathogens to cause plant disease and the ability of bacterial antagonists to suppress disease. Antibiotic production by antagonists, which contributes to disease suppression, is known to be modulated by abiotic and host plant environmental conditions. Here, we demonstrate that a pathogen metabolite functions as a negative signal for bacterial antibiotic biosynthesis, which can determine the relative importance of biological control mechanisms available to antagonists and which may also influence fungus-bacterium ecological interactions. We found that production of the polyketide antibiotic 2,4-diacetylphloroglucinol (DAPG) was the primary biocontrol mechanism of Pseudomonas fluorescens strain Q2-87 against Fusarium oxysporum f. sp. radicis-lycopersici on the tomato as determined with mutational analysis. In contrast, DAPG was not important for the less-disease-suppressive strain CHA0. This was explained by differential sensitivity of the bacteria to fusaric acid, a pathogen phyto- and mycotoxin that specifically blocked DAPG biosynthesis in strain CHA0 but not in strain Q2-87. In CHA0, hydrogen cyanide, a biocide not repressed by fusaric acid, played a more important role in disease suppression.

Duffy, Brion; Keel, Christoph; Defago, Genevieve

2004-01-01

257

Immunodominant antigens in Naegleria fowleri excretory--secretory proteins were potential pathogenic factors.  

PubMed

Naegleria fowleri, a ubiquitous pathogenic free-living amoeba, is the most virulent species and causes primary amoebic meningoencephalitis in laboratory animals and humans. The parasite secretes various inducing molecules as biological responses, which are thought to be involved in pathophysiological and immunological events during infection. To investigate what molecules of N. fowleri excretory-secretory proteins (ESPs) are related with amoebic pathogenicity, N. fowleri ESPs fractionated by two-dimensional electrophoresis were reacted with N. fowleri infection or immune sera. To identify immunodominant ESPs, six major protein spots were selected and analyzed by N-terminal sequencing. Finally, six proteins, 58, 40, 24, 21, 18, and 16 kDa of molecular weight, were partially cloned and matched with reference proteins as follow: 58 kDa of exendin-3 precursor, 40 kDa of secretory lipase, 24 kDa of cathepsin B-like proteases and cysteine protease, 21 kDa of cathepsin B, 18 kDa of peroxiredoxin, and 16 kDa of thrombin receptor, respectively. These results suggest that N. fowleri ESPs contained important proteins, which may play an important role in the pathogenicity of N. fowleri. PMID:19756751

Kim, Jong-Hyun; Yang, Ae-Hee; Sohn, Hae-Jin; Kim, Daesik; Song, Kyoung-Ju; Shin, Ho-Joon

2009-11-01

258

Potential role of pathogen signaling in multitrophic plant-microbe interactions involved in disease protection.  

PubMed

Multitrophic interactions mediate the ability of fungal pathogens to cause plant disease and the ability of bacterial antagonists to suppress disease. Antibiotic production by antagonists, which contributes to disease suppression, is known to be modulated by abiotic and host plant environmental conditions. Here, we demonstrate that a pathogen metabolite functions as a negative signal for bacterial antibiotic biosynthesis, which can determine the relative importance of biological control mechanisms available to antagonists and which may also influence fungus-bacterium ecological interactions. We found that production of the polyketide antibiotic 2,4-diacetylphloroglucinol (DAPG) was the primary biocontrol mechanism of Pseudomonas fluorescens strain Q2-87 against Fusarium oxysporum f. sp. radicis-lycopersici on the tomato as determined with mutational analysis. In contrast, DAPG was not important for the less-disease-suppressive strain CHA0. This was explained by differential sensitivity of the bacteria to fusaric acid, a pathogen phyto- and mycotoxin that specifically blocked DAPG biosynthesis in strain CHA0 but not in strain Q2-87. In CHA0, hydrogen cyanide, a biocide not repressed by fusaric acid, played a more important role in disease suppression. PMID:15006813

Duffy, Brion; Keel, Christoph; Défago, Geneviève

2004-03-01

259

Relationships between nasal potential difference and respiratory function in adults with cystic fibrosis  

Microsoft Academic Search

This study investigated the relations between nasal transepithelial elec- tric potential difference (PD) and the phenotype and genotype of cystic fibrosis (CF) adult patients. Basal nasal PD was measured in 95 adult CF patients who were classified into three groups of nasal PD (expressed as absolute values) according to the 10th and the 90th percentiles (28.3 and 49.2 mV, respectively),

I. Fajac; D. Hubert; T. Bienvenu; B. Richaud-Thiriez; R. Matran; J. C. Kaplan; J. Dall'Ava-Santucci; D. J. Dusser

1998-01-01

260

Potential Usefulness of Inflammatory Markers to Monitor Respiratory Functional Impairment in Sarcoidosis  

Microsoft Academic Search

Background: Sarcoidosis is a multiorgan inflammatory granulomatous disorder of unknown origin for which adequate markers to monitor disease severity are lack- ing. The aim of this study was to evaluate the potential clinical usefulness of serologic markers of inflammation (high-sensitivity C-reactive protein (hs-CRP) and serum amyloid A (SAA)), T-cell activation (soluble interleu- kin-2 receptor (sIL2R)), and granuloma formation (an- giotensin-converting

Marja P. van Dieijen-Visser; Paul G. H. Mulder; Marjolein Drent

261

Validity of Methods to Predict the Respiratory Sensitizing Potential of Chemicals: A Study with a Piperidinyl Chlorotriazine Derivative That Caused an Outbreak of Occupational Asthma  

Microsoft Academic Search

A piperidinyl chlorotriazine (PCT) derivative, used as a plastic UV-stabilizer, caused an outbreak of occupational asthma. We verified, in BALB\\/c mice, the sensitizing potential of PCT in comparison to a known respiratory sensitizer (toluene diisocya- nate (TDI)) and a known dermal sensitizer (oxazolone), using three different methods in order to evaluate the validity of current models of sensitization. These included

Jeroen A. J. Vanoirbeek; Cindy Mandervelt; Albert R. Cunningham; Peter H. M. Hoet; Haiyan Xu; Hadewijch M. Vanhooren; Benoit Nemery

2003-01-01

262

The mouse IgE test for the identification of potential chemical respiratory allergens: considerations of stability and controls.  

PubMed

The mouse IgE test is a novel approach to the predictive identification of chemicals that have the potential to cause sensitization of the respiratory tract. The method is based upon measurement of induced changes in the serum concentration of IgE in BALB/c strain mice following topical exposure to the test chemical. The investigations described here were undertaken to examine the stability of the assay, to evaluate the utility of trimellitic anhydride (TMA) and 2,4-dinitrochlorobenzene (DNCB) as, respectively, positive and negative controls for use in the test and to consider criteria for the classification of chemicals as potential respiratory allergens based upon changes induced in serum IgE concentration. On the basis of fifteen independent experiments it was found that, while there was some intra- and inter-test variability with respect to absolute concentrations of IgE measured in the sera of individual mice, the relative pattern of reactivity observed following treatment of mice with TMA, DNCB or with vehicle (4:1 acetone:olive oil) alone remained consistent. In each experiment treatment with TMA provoked a very substantial increase in serum IgE relative to vehicle controls. In no instance did exposure of mice to DNCB cause an increase in the concentration of serum IgE, and in some instances treatment with this chemical resulted in reduced IgE levels. In a parallel series of experiments it was found that serum IgE concentrations in vehicle-treated mice were comparable with those found in the serum of untreated animals. It is concluded that the differential ability of chemicals to induce changes in the concentration of serum IgE in BALB/c mice is a stable phenomenon. It is recommended that, in practice, TMA and DNCB should be incorporated in mouse IgE tests as, respectively, positive and negative controls. Finally, it is proposed that activity in the test is assessed as a function of induced changes in serum IgE levels relative to concurrent vehicle controls, rather than by reference to historical normal range values. PMID:8935793

Hilton, J; Dearman, R J; Boylett, M S; Fielding, I; Basketter, D A; Kimber, I

1996-01-01

263

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

264

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

265

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.

Mooney, Alaina J; Tompkins, S Mark

2013-01-01

266

Impact of Implementing 5 Potentially Better Respiratory Practices on Neonatal Outcomes and Costs  

PubMed Central

OBJECTIVE: We implemented 5 potentially better practices to limit mechanical ventilation (MV), supplemental oxygen, and bronchopulmonary dysplasia in newborn infants born before 33 weeks' gestation. METHODS: The methods used in this study included (1) exclusive use of bubble continuous positive airway pressure (bCPAP), (2) provision of bCPAP in the delivery room, (3) strict intubation criteria, (4) strict extubation criteria, and (5) prolonged CPAP to avoid supplemental oxygen. We excluded outborn infants and those with major anomalies and obstetric complications from analysis. RESULTS: Demographics were similar in 61 infants born before and 60 born after implementation. For infants born at 26 to 3267 weeks' gestation, intubation (first 72 hours) decreased from 52% to 11% (P < .0001) and surfactant use decreased from 48% to 14% (P = .0001). In all infants, the mean ± SD fraction of inspired oxygen requirement (first 24 hours) decreased from 0.27 ± 0.08 to 0.24 ± 0.05 (P = .0005), days of oxygen decreased from 23.5 ± 44.5 to 9.3 ± 22.0 (P = .04), and days of MV decreased from 8.8 ± 27.8 to 2.2 ± 6.2 (P = .005). Hypotension decreased from 33% to 15% (P = .03). The percentage of infants with bronchopulmonary dysplasia was 17% before and 8% after (P = .27). Nurse staffing ratios remained unchanged. CONCLUSIONS: Implementation of these potentially better practices reduced the need for MV, surfactant, and supplemental oxygen as well as reduced hypotension among infants born before 33 weeks' gestation without adverse consequences. The costs for equipment and surfactant were lower.

Kalish, Leslie A.; LaPierre, Justine; Welch, Maureen; Porter, Virginia

2011-01-01

267

Acute lower respiratory infections in >=5 year -old hospitalized patients in Cambodia, a low-income tropical country: clinical characteristics and pathogenic etiology  

PubMed Central

Background Few data exist on viral and bacterial etiology of acute lower respiratory infections (ALRI) in ?5 year –old persons in the tropics. Methods We conducted active surveillance of community-acquired ALRI in two hospitals in Cambodia, a low-income tropical country. Patients were tested for acid-fast bacilli (AFB) by direct sputum examination, other bacteria by blood and/or sputum cultures, and respiratory viruses using molecular techniques on nasopharyngeal/throat swabs. Pulmonologists reviewed clinical/laboratory data and interpreted chest X-rays (CXR) to confirm ALRI. Results Between April 2007 - December 2009, 1,904 patients aged ?5 years were admitted with acute pneumonia (50.4%), lung sequelae-associated ALRI (24.3%), isolated pleural effusions (8.9%) or normal CXR-related ALRI (17.1%); 61 (3.2%) died during hospitalization. The two former diagnoses were predominantly due to bacterial etiologies while viral detection was more frequent in the two latter diagnoses. AFB-positive accounted for 25.6% of acute pneumonia. Of the positive cultures (16.8%), abscess-prone Gram-negative bacteria (39.6%) and Haemophilus influenzae (38.0%) were most frequent, followed by Streptococcus pneumoniae (17.7%). Of the identified viruses, the three most common viruses included rhinoviruses (49.5%), respiratory syncytial virus (17.7%) and influenza viruses (12.1%) regardless of the diagnostic groups. Wheezing was associated with viral identification (31.9% vs. 13.8%, p?respiratory viruses and wheezing merits further studies.

2013-01-01

268

Potential effect of Curcuma longa extract on infectivity and pathogenicity of Schistosoma mansoni cercariae.  

PubMed

Batch of freshly shed cercariae from infected laboratory bred Biomphalaria alexandrina were exposed to different sub-lethal concentrations of turmeric extract for an hour and divided into two groups. The first one was to study the ultrastructural changes induced in them using scanning electron microscopy (SEM). The second group was to study infectivity and pathogenicity of the exposed cercariae. One hundred and fifty mice were divided into 5 groups: GI: Infected by normal cercariae and served as controls; GII, GIII, GIV & GV infected by cercariae exposed to 2.5, 5, 7.5 & 10 ppm, respectively. Ten weeks post infection all animals were sacrificed and subjected to parasitologic, histopathologic and immunologic assays. SEM showed cercariae exposed to 5 ppm with minimal destruction of head spines and tail. The degenerative changes were progressively severe by increasing extract concentration to reach complete destruction of both at 10 ppm. Infectivity decreased with the increase in concentration to reach highest significance at 10 ppm. Pathogenicity or mean number of egg deposited, mean diameter of liver granulomas and level of IL-10 gene expression significantly decreased in Gs IV & V. PMID:19143127

Shoheib, Zeinab S; El-Nouby, Kholoud A; Deyab, Fetouh A; Dar, Yasser D; Kabbash, Amal M

2008-04-01

269

Potentially pathogenic amoeba-associated microorganisms in cooling towers and their control.  

PubMed

Cooling towers provide a favorable environment for the proliferation of microorganisms. Cooling towers generate a biofilm and often aerosolize contaminated water, thereby increasing the risk of microorganism dissemination by human inhalation. This pathogen dissemination was first revealed by the epidemics of Legionnaires' disease that were directly related to the presence of cooling towers, and since then, the ecology of Legionella pneumophila has been well studied. Each country has specific standards regarding the acceptable amount of microorganisms in cooling tower systems. However, those standards typically only concern L. pneumophila, even though many other microorganisms can also be isolated from cooling towers, including protozoa, bacteria and viruses. Microbiological control of the cooling tower system can be principally achieved by chemical treatments and also by improving the system's construction. Several new treatments are being studied to improve the efficiency of disinfection. However, as most of these treatments continue to focus solely on L. pneumophila, reports of other types of pathogens continue to increase. Therefore, how their dissemination affects the human populous health should be addressed now. PMID:19492970

Pagnier, Isabelle; Merchat, Michèle; La Scola, Bernard

2009-06-01

270

Felis catus gammaherpesvirus 1; a widely endemic potential pathogen of domestic cats.  

PubMed

Felis catus gammaherpesvirus 1 (FcaGHV1), recently discovered in the USA, was detected in domestic cats in Australia (11.4%, 95% confidence interval 5.9-19.1, n=110) and Singapore (9.6%, 95% confidence interval 5.9-14.6, n=176) using qPCR. FcaGHV1 qPCR positive cats were 2.8 times more likely to be sick than healthy. Risk factors for FcaGHV1 detection included being male, increasing age and coinfection with pathogenic retroviruses, feline immunodeficiency virus (FIV) or feline leukaemia virus. FcaGHV1 DNA was detected in multiple tissues from infected cats with consistently high virus loads in the small intestine. FcaGHV1 viral load was significantly higher in FIV-infected cats compared with matched controls, mimicking increased Epstein-Barr virus loads in human immunodeficiency virus-infected humans. FcaGHV1 is endemic in distant geographic regions and is associated with being sick and with coinfections. Horizontal transmission of FcaGHV1 is supported, with biting being a plausible route. A pathogenic role for FcaGHV1 in domestic cats is supported. PMID:25010275

Beatty, Julia A; Troyer, Ryan M; Carver, Scott; Barrs, Vanessa R; Espinasse, Fanny; Conradi, Oliver; Stutzman-Rodriguez, Kathryn; Chan, Cathy C; Tasker, Séverine; Lappin, Michael R; VandeWoude, Sue

2014-07-01

271

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

272

Discrepancy between antibiotics administered in acute exacerbations of chronic bronchitis and susceptibility of isolated pathogens in respiratory samples: multicentre study in the primary care setting  

Microsoft Academic Search

A national multicentre prevalence study was undertaken to determine the bacterial strains associated with mild-to-moderate acute exacerbations of chronic bronchitis (AECB) in the primary care setting and the susceptibility of isolated pathogens to different antimicrobials usually prescribed to these patients. All samples were processed by a central reference laboratory. Microdilution tests were carried out to establish the minimum inhibitory concentration

J. M. Querol-Ribelles; J. Molina; K. Naberan; E. Esteban; A. Herreras; J. Garcia-de-Lomas

2006-01-01

273

Opportunistic invasive fungal pathogen Macrophomina phaseolina prognosis from immunocompromised humans to potential mitogenic RBL with an exceptional and novel antitumor and cytotoxic effect.  

PubMed

With the ever-increasing risk for fungal infections, one can no longer ignore fungi. It is imperative that clinical manifestations "presume fungus" with their epidemiologic and pathogenic features when evaluating a potentially infected patient. In the high-risk patient groups, fungi with intrinsic resistance to antifungal agents already exist, with a tendency to emerge as opportunistic pathogens. One of the smart pathogens is Macrophomina phaseolina, with the potential to disarm plant, animal, and human immunity. The response prophylaxis may vary from antifungal therapy and surgical measures to biochemical (Rhizoctonia bataticola lectin [RBL] with antitumor and cytotoxic nature) and gene therapeutics. PMID:21553299

Arora, P; Dilbaghi, N; Chaudhury, A

2012-02-01

274

Neutralizing Human Monoclonal Antibodies to Severe Acute Respiratory Syndrome Coronavirus: Target, Mechanism of Action and Therapeutic Potential  

PubMed Central

Summary The emergence of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) led to a rapid response not only to contain the outbreak but also to identify possible therapeutic interventions, including the generation of human monoclonal antibodies (hmAbs). Human mAbs may be used therapeutically without the drawbacks of chimeric or animal Abs. Several different methods have been used to generate SARS-CoV specific neutralizing hmAbs including the immunization of transgenic mice, cloning of small chain variable regions from naïve and convalescent patients, and the immortalization of convalescent B cells. Irrespective of the techniques used, the majority of hmAbs specifically reacted with the receptor binding domain (RBD) of the spike (S) protein and likely prevented receptor binding. However, several hmAbs that can bind to epitopes either within the RBD, located N terminal of the RBD or in the S2 domain and neutralize the virus with or without inhibiting receptor binding have been identified. Therapeutic utility of hmAbs has been further elucidated through the identification of potential combinations of hmAbs that could neutralize viral variants including escape mutants selected using hmAbs. These results suggest that a cocktail of hmAbs which can bind to unique epitopes and have different mechanisms of action might be of clinical utility against SARS-CoV infection, and indicate that a similar approach may be applied to treat other viral infections.

Coughlin, Melissa M.; Prabhakar, Bellur S.

2011-01-01

275

Investigations on the prevalence and potential pathogenicity of intestinal trichomonads in pigs using in situ hybridization  

PubMed Central

In pigs, three different trichomonad species (Tritrichomonas foetus, Tetratrichomonas buttreyi and Tritrichomonas rotunda) have been described as commensals in the large intestine. The aim of this study was to gain further knowledge on the prevalence and pathogenicity of trichomonads in pigs by using a morphology-based approach. Chromogenic in situ hybridization (ISH) is a technique which allows direct localization of the protozoa in the intestinal tissue and correlation of the infection with pathologic changes. In the present study paraffin-wax embedded colon and ileum samples of 192 pigs were analyzed with this method. Using a probe specific for all known members of the order Trichomonadida (OT) 100 of the 192 pigs were tested positive. Thereof, about 10% showed moderate to high-grade parasitic load with trichomonads invading the lamina propria. Partial 18S ribosomal RNA gene sequencing of six of those animals showed a 100% sequence identity with T. foetus sequences. The majority of these animals were also tested positive for other enteropathogenic agents, such as Brachyspira sp., Lawsonia intracellularis, Escherichia coli, and porcine circovirus type 2. All OT-positive samples were further examined with another probe complementary to all known Tritrichomonas species sequences including T. foetus, T. augusta, T. mobilensis and T. nonconforma resulting in only 48 positives. These results suggest that T. foetus may not only be considered as an intestinal commensal but rather a facultative pathogen of pigs with a tendency for tissue invasion in the presence of other agents. Furthermore, the existence of other – yet to be identified – trichomonad species in the colon of pigs was shown.

Mostegl, Meike M.; Richter, Barbara; Nedorost, Nora; Maderner, Anton; Dinhopl, Nora; Weissenbock, Herbert

2011-01-01

276

Lactobacillus crispatus L1: high cell density cultivation and exopolysaccharide structure characterization to highlight potentially beneficial effects against vaginal pathogens  

PubMed Central

Background Vaginal lactic acid bacteria defend the host against pathogens through a combination of competitive exclusion, competition for nutrients, production of antimicrobial substances and through the activation of the immune system. A new human isolate named Lactobacillus crispatus L1 was characterized in this work, and a preliminary evaluation of its probiotic potential is described together with a process to obtain a high productivity of viable biomass. Results In a simulated digestion process 1.8?1010 cells?ml?1 survived the gastric environment with 80% viability, without being affected by small intestine juices. Experiments on six different C sources were performed to analyze growth and organic acids production and, glucose, provided the best performances. A microfiltration strategy was exploited to improve the cellular yield in 2 L-fermentation processes, reaching 27 g?·?l?1 of dry biomass. Moreover, L. crispatus L1 demonstrated a greater stability to high concentrations of lactic acid, compared to other lactobacilli. The specific L. crispatus L1 exopolysaccharide was purified from the fermentation broth and characterized by NMR showing structural features and similarity to exopolysaccharides produced by pathogenic strains. Live L. crispatus L1 cells strongly reduced adhesion of a yeast pathogenic strain, Candida albicans in particular, in adherence assays. Interestingly a higher expression of the human defensin HBD-2 was also observed in vaginal cells treated with the purified exopolysaccharide, indicating a possible correlation with C. albicans growth inhibition. Conclusions The paper describes the evaluation of L. crispatus L1 as potential vaginal probiotic and the fermentation processes to obtain high concentrations of viable cells.

2014-01-01

277

Identification of nonessential regions of the nsp2 protein of an attenuated vaccine strain (HuN4-F112) of highly pathogenic porcine reproductive and respiratory syndrome virus for replication in marc-145 cell  

PubMed Central

Background The regions in the middle of nonstructural protein 2 (nsp2) of porcine reproductive and respiratory syndrome virus (PRRSV) have been shown to be nonessential for PRRSV replication, and these nonessential regions are different in various viral strains. Finding In this study, the nonessential regions of the nsp2 of an attenuated vaccine strain (HuN4-F112) of highly pathogenic porcine reproductive and respiratory syndrome virus were identified based on an infectious cDNA clone of HuN4-F112. The results demonstrated that the segments of nsp2 [amino acids (aa) 480 to 667] tolerated deletions. Characterization of the mutants demonstrated that those with small deletions did not affect the viral growth on Marc-145 cells, but deletion of these regions led to earlier PRRSV replication increased (before 36?h after infectious in vitro). Conclusion The functional roles of nsp2 variable middle region for PRRSV HuN4-F112 replication have been identified. Our results also suggested that none-essential region might be an ideal insertion region to express foreign gene in PRRSV genome.

2012-01-01

278

Potentially pathogenic free-living amoebae in some flood-affected areas during 2011 Chiang Mai flood.  

PubMed

The survey was carried out to investigate the presence of potentially pathogenic free-living amoebae (FLA) during flood in Chiang Mai, Thailand in 2011. From different crisis flood areas, seven water samples were collected and tested for the presence of amoebae using culture and molecular methods. By monoxenic culture, FLA were detected from all samples at 37 °C incubation. The FLA growing at 37 °C were morphologically identified as Acanthamoeba spp., Naegleria spp. and some unidentified amoebae. Only three samples (42.8%), defined as thermotolerant FLA, continued to grow at 42 °C. By molecular methods, two non-thermotolerant FlA were shown to have 99% identity to Acanthamoeba sp. and 98% identity to Hartmannella vermiformis while the two thermotolerant FLA were identified as Echinamoeba exundans (100% identity) and Hartmannella sp. (99% identity). This first report of the occurrence of FLA in water during the flood disaster will provide information to the public to be aware of potentially pathogenic FLA. PMID:24213194

Wannasan, Anchalee; Uparanukraw, Pichart; Songsangchun, Apichart; Morakote, Nimit

2013-01-01

279

POTENTIALLY PATHOGENIC FREE-LIVING AMOEBAE IN SOME FLOOD-AFFECTED AREAS DURING 2011 CHIANG MAI FLOOD  

PubMed Central

SUMMARY The survey was carried out to investigate the presence of potentially pathogenic free-living amoebae (FLA) during flood in Chiang Mai, Thailand in 2011. From different crisis flood areas, seven water samples were collected and tested for the presence of amoebae using culture and molecular methods. By monoxenic culture, FLA were detected from all samples at 37 °C incubation. The FLA growing at 37 °C were morphologically identified as Acanthamoeba spp., Naegleria spp. and some unidentified amoebae. Only three samples (42.8%), defined as thermotolerant FLA, continued to grow at 42 °C. By molecular methods, two non-thermotolerant FlA were shown to have 99% identity to Acanthamoeba sp. and 98% identity to Hartmannella vermiformis while the two thermotolerant FLA were identified as Echinamoeba exundans (100% identity) and Hartmannella sp. (99% identity). This first report of the occurrence of FLA in water during the flood disaster will provide information to the public to be aware of potentially pathogenic FLA.

Wannasan, Anchalee; Uparanukraw, Pichart; Songsangchun, Apichart; Morakote, Nimit

2013-01-01

280

Antimicrobial potential of bacteriocin producing Lysinibacillus jx416856 against foodborne bacterial and fungal pathogens, isolated from fruits and vegetable waste.  

PubMed

In this study, antimicrobial potential, some probiotics properties and bacteriocin nature of Lysinibacillus, isolated from fruits and vegetable waste were evaluated. For this, 125 Lactobacillus isolates were tested against foodborne bacterial and fungal pathogens. Among these, an isolated Bacillus spp. showed significant aggregation-co-aggregation probiotics properties and potentially inhibits the foodborne gram positive microbial pathogens such as Staphylococcus aureus, (22 mm ZOI), Staphylococcus epedermidis and Bacillus cereus (18 mm). Phenotypically and molecularly it was identified as Lysinibacillus (NCBI accession no. JX416856) and it was found closest to Lysinibacillus fusiformis, Lysinibacillus sphaericus and Lysinibacillus xylanilyticus. Physico-biochemically, it was found to be negative for amylase, protease, gelatinase, nitrate reductase and urease while positive for catalase. The diagnostic fatty acid was 22;2 (3.51). The growth conditions and bacteriocin activity were found to be optimum with MRS media at pH 7-10, Temperature 35-40 °C and salt tolerance at 1-3%. Eventually its production was optimized with MRS broth at pH 7.6, 37 °C, for 36 h in shaking conditions at the rate of 100 rpm. Active bacteriocin was isolated at 60% ammonium sulfate precipitation. The molecular weight of given bacteriocin was found to be nearly 25-35 kDa by SDS-PAGE. Based on physico- biochemical properties, the isolated bacteriocin was to be categories in class II bacteriocin. The bacteriocin was found to be stable in the range of 4-80 °C temperature, 6-10 pH and even in the presence of surfactant (such as SDS and Tween 80). However, proteases like pepsin and trypsin were found to degrade the bacteriocin. Collectively, the broad spectrum inhibitory potential and physical stability offered the antimicrobial potential to Lysinibacillus, and its relevant bacteriocin might be used as an alternative food preservative or therapeutic agent to control spoilage of different food products. PMID:24735603

Ahmad, Varish; Muhammad Zafar Iqbal, A N; Haseeb, Mohd; Khan, Mohd Sajid

2014-06-01

281

Influenza Virus Respiratory Infection and Transmission Following Ocular Inoculation in Ferrets  

PubMed Central

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 entry for establishment of a respiratory infection. However, the properties which govern ocular tropism of influenza viruses, the mechanisms of virus spread from ocular to respiratory tissue, and the potential differences in respiratory disease initiated from different exposure routes are poorly understood. Here, we established a ferret model of ocular inoculation to explore the development of virus pathogenicity and transmissibility following influenza virus exposure by the ocular route. We found that multiple subtypes of human and avian influenza viruses mounted a productive virus infection in the upper respiratory tract of ferrets following ocular inoculation, and were additionally detected in ocular tissue during the acute phase of infection. H5N1 viruses maintained their ability for systemic spread and lethal infection following inoculation by the ocular route. Replication-independent deposition of virus inoculum from ocular to respiratory tissue was limited to the nares and upper trachea, unlike traditional intranasal inoculation which results in virus deposition in both upper and lower respiratory tract tissues. Despite high titers of replicating transmissible seasonal viruses in the upper respiratory tract of ferrets inoculated by the ocular route, virus transmissibility to naïve contacts by respiratory droplets was reduced following ocular inoculation. These data improve our understanding of the mechanisms of virus spread following ocular exposure and highlight differences in the establishment of respiratory disease and virus transmissibility following use of different inoculation volumes and routes.

Belser, Jessica A.; Gustin, Kortney M.; Maines, Taronna R.; Pantin-Jackwood, Mary J.; Katz, Jacqueline M.; Tumpey, Terrence M.

2012-01-01

282

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

283

Zoonotic potential of multidrug-resistant extraintestinal pathogenic Escherichia coli obtained from healthy poultry carcasses in Salvador, Brazil.  

PubMed

The zoonotic potential to cause human and/or animal infections among multidrug-resistant extraintestinal pathogenic Escherichia coli from avian origin was investigated. Twenty-seven extraintestinal pathogenic E. coli isolates containing the increased survival gene (iss) were obtained from the livers of healthy and diseased poultry carcasses at two slaughterhouses in Salvador, northeastern Brazil. The antimicrobial resistance-susceptibility profiles were conducted with antibiotics of avian and/or human use by the standardized disc-diffusion method. Antimicrobial resistance was higher for levofloxacin (51.8%), amoxicillin/clavulanic acid (70.4%), ampicillin (81.5%), cefalotin (88.8%), tetracycline (100%) and streptomycin (100%). The minimum inhibitory concentrations above the resistance breakpoints of doxycycline, neomycin, oxytetracycline and enrofloxacin reached, respectively, 88.0%, 100%, 75% and 91.7% of the isolates. Strains with high and low antimicrobial resistance were i.p. administered to Swiss mice, and histopathological examination was carried out seven days after infection. Resistance to goat and human serum complement was also evaluated. The results show that Swiss mice challenged with strain 2B (resistant to 11 antimicrobials) provoked a severe degeneration of hepatocytes besides lymphocytic infiltration in the liver, whereas the spleen showed areas of degeneration of the white and red pulp. Conversely, the spleen and liver of mice challenged with strain 4A (resistant to two antimicrobials) were morphologically preserved. In addition, complement resistance to goat and human serum was high for strain 2B and low for strain 4A. Our data show that multidrug resistance and pathogenesis can be correlated in extraintestinal pathogenic E. coli strains obtained from apparently healthy poultry carcasses, increasing the risk for human public healthy. PMID:23290470

Lima-Filho, José Vitor; Martins, Liliane Vilela; Nascimento, Danielle Cristina de Oliveira; Ventura, Roberta Ferreira; Batista, Jacqueline Ellen Camelo; Silva, Ayrles Fernanda Brandão; Ralph, Maria Taciana; Vaz, Renata Valença; Rabello, Carlos Boa-Viagem; Silva, Isabella de Matos Mendes da; Evêncio-Neto, Joaquim

2013-01-01

284

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

285

Antimicrobial potential for the combination of bovine lactoferrin or its hydrolysate with lactoferrin-resistant probiotics against foodborne pathogens.  

PubMed

Previous reports have shown that several probiotic strains can resist the antibacterial activity of bovine lactoferrin (bLf), but the results are inconsistent. Moreover, a portion of orally administered apo-bLf is digested in vivo by pepsin to yield bLf hydrolysate, which produces stronger antibacterial activity than that observed with apo-bLf. However, whether bLf hydrolysate affects the growth of probiotic strains is unclear. Therefore, various probiotic strains in Taiwan were collected and evaluated for activity against apo-bLf and bLf hydrolysate in vitro. Thirteen probiotic strains were evaluated, and the growth of Lactobacillus acidophilus ATCC 4356, Lactobacillus salivarius ATCC 11741, Lactobacillus rhamnosus ATCC 53103, Bifidobacterium longum ATCC 15707, and Bifidobacterium lactis BCRC 17394 were inhibited by both apo-bLf and bLf hydrolysate. The growth of 8 strains were not affected by apo-bLf and bLf hydrolysate, including L. rhamnosus ATCC 7469, Lactobacillus reuteri ATCC 23272, Lactobacillus fermentum ATCC 11739, Lactobacillus coryniformis ATCC 25602, L. acidophilus BCRC 14065, Bifidobacterium infantis ATCC 15697, Bifidobacterium bifidum ATCC 29521, and Pediococcus acidilactici ATCC 8081. However, apo-bLf and its hydrolysate inhibited the growth of foodborne pathogens, including Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Enterococcus faecalis. Moreover, the supernatants produced by L. fermentum, B. lactis, and B. longum inhibited the growth of most pathogens. Importantly, a combination of apo-bLf or bLf hydrolysate with the supernatants of cultures of the organisms described above showed synergistic or partially synergistic effects against the growth of most of the selected pathogens. In conclusion, several probiotic strains are resistant to apo-bLf and bLf hydrolysate, warranting clinical studies to evaluate the antimicrobial potential for the combination of apo-bLf or its hydrolysate with specific probiotics. PMID:23332852

Chen, P-W; Jheng, T T; Shyu, C-L; Mao, F C

2013-03-01

286

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

287

Fungal pathogens of Euphorbia heterophylla and E. hirta in Brazil and their potential as weed biocontrol agents.  

PubMed

A two-year survey of the fungi associated with two important congeneric pantropical weeds, Euphorbia heterophylla and E. hirta, was conducted in part of their native range in southern Brazil. Sampling was concentrated mainly in Rio de Janeiro State and ten species were identified as pathogens of these weeds. Two taxa, Botrytis ricini and Uromyces euphorbiae, were common to both weed hosts. Alternaria euphorbiicola, Bipolaris euphorbiae, Melampsora sp., Oidium sp. and Sphaceloma poinsettiae were recorded only from E. heterophylla, whereas Colletotrichum gloeosporioides, Sphaceloma sp. and Sphaerotheca fuliginea were restricted to E. hirta. Botrytis ricini and Colletotrichum gloeosporioides are new records for E. hirta, and Alternaria euphorbiicola and Sphaerotheca fuliginea are new host records for Brazil. Bipolaris euphorbiae, previously identified as Helminthosporium sp., is considered to be the correct name for the causal agent of a major disease of E. heterophyllum in Brazil. The potential of these pathogens as biocontrol agents is discussed and the mycobiota associated with both these weeds worldwide is reviewed. PMID:16284862

Barreto, R W; Evans, H C

1998-01-01

288

Molecular detection of potential sexually transmitted pathogens in semen and urine specimens of infertile and fertile males.  

PubMed

A total of 93 infertile and 70 fertile men attending various urology and gynecology clinics in Jordan were investigated in this prospective study. First void urine and the corresponding semen specimens were collected from 96% of the patients. Presence of Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), Ureaplasma urealyticum (UU), and Mycoplasma genitalium (MG) DNA in specimen was detected using polymerase chain reaction. The distribution of NG, CT, UU, and MG in semen and FVU specimens among infertile versus fertile men was 6.5% versus 0%, 4.3% versus 1.4%, 10.8% versus 5.7%, and 3.2% versus 1.4%, respectively. Two of infertile and 1 of fertile men harbored mixed pathogens. The highest number of positive potential pathogens was found among young men aged 20-29 years old. The present study found a very high concordance between the detection of CT, UU, and MG DNA in semen and the corresponding FVU specimens, while NG DNA found only in semen and not in the corresponding FVU specimens. This study also revealed that Ureaplasma parvum species is more prevalent than Ureaplasma urealyticum in specimens of infertile men (90%). The study demonstrates that infertile men have higher prevalence of NG, CT, UU, and MG compared with fertile men and NG as significantly associated with infertile men. PMID:24079950

Abusarah, Eman A; Awwad, Ziad M; Charvalos, Ekatherina; Shehabi, Asem A

2013-12-01

289

Molecular Mechanisms of Host-Pathogen Interactions and their Potential for the Discovery of New Drug Targets  

PubMed Central

Vaccines and chemotherapy have undeniably been the discoveries in the field of biomedical research that have exerted the biggest impact on the improvement of public health. Nevertheless, the development of bacterial resistance to antibiotics has co-evolved over time with the discovery of new drugs. This entails the necessity for continuous research on new anti-infectious agents.The current review highlights recent discoveries in the molecular mechanisms of specific host pathogen interactions and their potential for drug discovery. The focus is on facultative and obligate intracellular pathogens (Mycobacterium, Chlamydia and Legionella) and their manipulation of host cells in regard to inhibition of phagosome maturation and cell death. Furthermore, the composition and role of the SecA2 and the ESX-1 secretion pathways in bacterial virulence and manipulation of infected host cells is discussed. The central hypothesis proposed in this review is that the characterization of bacterial proteins and lipids involved in host cell manipulation (modulins) will provide an abundance of new drug targets. One advantage of targeting such bacterial modulins for drug development is that these anti-modulin drugs will not disrupt the beneficial host microflora and therefore have fewer side effects.

Briken, Volker

2008-01-01

290

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

291

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.

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

2014-01-01

292

A Comparative Chemogenomics Strategy to Predict Potential Drug Targets in the Metazoan Pathogen, Schistosoma mansoni  

Microsoft Academic Search

Schistosomiasis is a prevalent and chronic helmintic disease in tropical regions. Treatment and control relies on chemotherapy with just one drug, praziquantel and this reliance is of concern should clinically relevant drug resistance emerge and spread. Therefore, to identify potential target proteins for new avenues of drug discovery we have taken a comparative chemogenomics approach utilizing the putative proteome of

Conor R. Caffrey; Andreas Rohwer; Frank Oellien; Richard J. Marhöfer; Simon Braschi; Guilherme Oliveira; James H. McKerrow; Paul M. Selzer

2009-01-01

293

Diversity of Alternaria alternata a common destructive pathogen of Eichhornia crassipes in Egypt and its potential use in biological control  

Microsoft Academic Search

Alternaria alternata is a pathogen of the Waterhyacinth (Eichhornia crassipes), which is an important weed in the Delta of the Nile. We conducted a survey of this pathogen at different sites in the Delta and isolated 400 strains. The colonization frequency of the pathogen was more than 85% in all tested sites. Isolate A was the most common isolate, while

El-Sayed M. El-Morsy; S. M. EL-Dohlob; K. D. Hyde

294

Recognition of Dermabacter hominis, formerly CDC fermentative coryneform group 3 and group 5, as a potential human pathogen.  

PubMed Central

Thirty strains of fermentative coryneform-like bacteria designated CDC fermentative coryneform group 3 and coryneform group 5 were compared biochemically by cellular fatty acid analysis and by DNA relatedness with the type strain of Dermabacter hominis, ATCC 49369. DNA from 22 strains of both CDC groups showed 69 to 96% relatedness (hydroxyapatite method) to labeled DNA from ATCC 49369 and to DNA from CDC group 3 strain G4964, and the strains are considered to belong to D. hominis. The remaining eight strains were genetically but not phenotypically differentiable from D. hominis. They were genetically heterogeneous, but hybridization results indicated that they probably belong to the genus Dermabacter. Thirteen of the 22 D. hominis strains and all 8 of the other Dermabacter strains had been isolated from blood, which indicates the pathogenic potential of this species and genus.

Gruner, E; Steigerwalt, A G; Hollis, D G; Weyant, R S; Weaver, R E; Moss, C W; Daneshvar, M; Brenner, D J

1994-01-01

295

Respiratory system  

NASA Technical Reports Server (NTRS)

The general anatomy and function of the human respiratory system is summarized. Breathing movements, control of breathing, lung volumes and capacities, mechanical relations, and factors relevant to respiratory support and equipment design are discussed.

Bartlett, R. G., Jr.

1973-01-01

296

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

297

Emerging Respiratory Viruses: Challenges and Vaccine Strategies  

PubMed Central

The current threat of avian influenza to the human population, the potential for the reemergence of severe acute respiratory syndrome (SARS)-associated coronavirus, and the identification of multiple novel respiratory viruses underline the necessity for the development of therapeutic and preventive strategies to combat viral infection. Vaccine development is a key component in the prevention of widespread viral infection and in the reduction of morbidity and mortality associated with many viral infections. In this review we describe the different approaches currently being evaluated in the development of vaccines against SARS-associated coronavirus and avian influenza viruses and also highlight the many obstacles encountered in the development of these vaccines. Lessons learned from current vaccine studies, coupled with our increasing knowledge of the host and viral factors involved in viral pathogenesis, will help to increase the speed with which efficacious vaccines targeting newly emerging viral pathogens can be developed.

Gillim-Ross, Laura; Subbarao, Kanta

2006-01-01

298

IL-4R? on CD4+ T cells plays a pathogenic role in respiratory syncytial virus reinfection in mice infected initially as neonates  

PubMed Central

RSV is the major cause of severe bronchiolitis in infants, and severe bronchiolitis as a result of RSV is associated with subsequent asthma development. A biased Th2 immune response is thought to be responsible for neonatal RSV pathogenesis; however, molecular mechanisms remain elusive. Our data demonstrate, for the first time, that IL-4R? is up-regulated in vitro on human CD4+ T cells from cord blood following RSV stimulation and in vivo on mouse pulmonary CD4+ T cells upon reinfection of mice, initially infected as neonates. Th cell-specific deletion of Il4ra attenuated Th2 responses and abolished the immunopathophysiology upon reinfection, including airway hyper-reactivity, eosinophilia, and mucus hyperproduction in mice infected initially as neonates. These findings support a pathogenic role for IL-4R? on Th cells following RSV reinfection of mice initially infected as neonates; more importantly, our data from human cells suggest that the same mechanism occurs in humans.

You, Dahui; Marr, Nico; Saravia, Jordy; Shrestha, Bishwas; Lee, Greg I.; Turvey, Stuart E.; Brombacher, Frank; Herbert, De'Broski R.; Cormier, Stephania A.

2013-01-01

299

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

SciTech Connect

Chrysotile (CH), the most common form of asbestos, is rendered less toxic by heating it at 1000 {sup o}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 this study, a single 2 mg dose of CH or FO-1000 was intratracheally administered to rats. Within 180 days after the administrations, serum N-ERC/mesothelin concentrations, levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in lung tissues and pathological changes in respiratory organs were determined. In the CH group, a significant increase in serum N-ERC/mesothelin concentrations was observed immediately after intratracheal administration, and the elevation lasted for 30 days. In lung tissues, positive staining for 8-OHdG in bronchioles, alveolar epithelium, inflammatory cells, and granulomas was evidence of a marked DNA oxidative damage. Furthermore, measurements of 8-OHdG in lung tissues based on the HPLC-ECD method suggested that serum N-ERC/mesothelin concentrations tended to increase when there are significant DNA damages in lung tissues. In contrast, in the FO-1000 group, a marked rise in serum N-ERC/mesothelin concentrations occurred only in the early phase (1-7 days) after intratracheal administration. Similarly, FO-1000 induced elevation of 8-OHdG in lung tissues was transient and modest compared with those of the CH-treated animals. In both the CH and FO-1000 groups, we observed significant correlations between serum N-ERC/mesothelin concentrations and lung 8-OHdG concentrations (r = 0.559, p = 0.001 for the CH group; r = 0.516, p = 0.01 for the FO-1000 group). In summary, we demonstrated the possibility of using serum N-ERC/mesothelin concentrations as a useful biomarker for early phase exposure to either CH or FO-1000.

Takata, Ayako [Department of Preventive Medicine, St. Marianna University School of Medicine, Kawasaki (Japan); Yamauchi, Hiroshi, E-mail: hyama@kitasato-u.ac.jp [Department of Public Health, School of Allied Health Science, Kitasato University, Sagamihara (Japan); Toya, Tadao [National Institute of Occupational Safety and Health, Kawasaki (Japan); Miyamoto-Kohno, Sayako; Iwatatsu, Yuka; Teranaka, Iroha [Department of Public Health, School of Allied Health Science, Kitasato University, Sagamihara (Japan); Aminaka, Masahito [Department of Preventive Medicine, St. Marianna University School of Medicine, Kawasaki (Japan); Yamashita, Kiyotsugu [Department of Public Health, School of Allied Health Science, Kitasato University, Sagamihara (Japan); Nozawa Corporation, Kobe (Japan); Kohyama, Norihiko [Natural Science Laboratory, Faculty of Economics, Toyo University, Tokyo (Japan)

2011-04-15

300

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

PubMed

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 this study, a single 2mg dose of CH or FO-1000 was intratracheally administered to rats. Within 180days after the administrations, serum N-ERC/mesothelin concentrations, levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in lung tissues and pathological changes in respiratory organs were determined. In the CH group, a significant increase in serum N-ERC/mesothelin concentrations was observed immediately after intratracheal administration, and the elevation lasted for 30days. In lung tissues, positive staining for 8-OHdG in bronchioles, alveolar epithelium, inflammatory cells, and granulomas was evidence of a marked DNA oxidative damage. Furthermore, measurements of 8-OHdG in lung tissues based on the HPLC-ECD method suggested that serum N-ERC/mesothelin concentrations tended to increase when there are significant DNA damages in lung tissues. In contrast, in the FO-1000 group, a marked rise in serum N-ERC/mesothelin concentrations occurred only in the early phase (1-7days) after intratracheal administration. Similarly, FO-1000 induced elevation of 8-OHdG in lung tissues was transient and modest compared with those of the CH-treated animals. In both the CH and FO-1000 groups, we observed significant correlations between serum N-ERC/mesothelin concentrations and lung 8-OHdG concentrations (r=0.559, p=0.001 for the CH group; r=0.516, p=0.01 for the FO-1000 group). In summary, we demonstrated the possibility of using serum N-ERC/mesothelin concentrations as a useful biomarker for early phase exposure to either CH or FO-1000. PMID:20933535

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

2011-04-15

301

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.

Kilic, Arman; Mandal, Kaushik

2012-01-01

302

Evaluation of the vaccine potential of a cytotoxic protease and a protective immunogen from a pathogenic Vibrio harveyi strain.  

PubMed

Vibrio harveyi is an important aquaculture pathogen that can infect a number of fish species and marine invertebrates. A putative protease, Vhp1, was identified from a pathogenic V. harveyi strain isolated from diseased fish as a protein with secretion capacity. Vhp1 is 530 amino acids in length and shares high sequence identities with several extracellular serine proteases of the Vibrio species. In silico analysis identified a protease domain in Vhp1, which is preceded by a subtilisin-N domain and followed by a bacterial pre-peptidase C-terminal domain. Purified recombinant protein corresponding to the protease domain of Vhp1 exhibited apparent proteolytic activity that was relatively heat-stable and reached maximum at pH 8.0 and 50 degrees C. The activity of purified recombinant Vhp1 protease was enhanced by Ca(2+) and inhibited by Mn(2+) and ethylenedinitrilotetraacetic acid. Cytotoxicity analyses indicated that recombinant Vhp1 protease was toxic to cultured Japanese flounder cells and could cause complete cell lysis. Immunoprotective analysis using Japanese flounder as an animal model showed that purified recombinant Vhp1 in the form of a denatured and proteolytically inactive protein was an effective subunit vaccine. To improve the vaccine potential of Vhp1, an Escherichia coli strain that expresses and secrets a cytotoxically impaired Vhp1 was constructed, which, when used as a live vaccine, afforded a high level of protection upon the vaccinated fish against lethal V. harveyi challenge. Taken together, these results demonstrate that Vhp1 is a cytotoxic protease and an effective vaccine candidate against V. harveyi infection. PMID:19897068

Cheng, Shuang; Zhang, Wei-wei; Zhang, Min; Sun, Li

2010-01-22

303

Rolipram attenuates bile duct ligation-induced liver injury in rats: a potential pathogenic role of PDE4.  

PubMed

Anti-inflammatory and antifibrotic effects of the broad spectrum phosphodiesterase (PDE) inhibitor pentoxifylline have suggested an important role for cyclic nucleotides in the pathogenesis of hepatic fibrosis; however, studies examining the role of specific PDEs are lacking. Endotoxemia and Toll-like receptor 4 (TLR4)-mediated inflammatory and profibrotic signaling play a major role in the development of hepatic fibrosis. Because cAMP-specific PDE4 critically regulates lipopolysaccharide (LPS)-TLR4-induced inflammatory cytokine expression, its pathogenic role in bile duct ligation-induced hepatic injury and fibrogenesis in Sprague-Dawley rats was examined. Initiation of cholestatic liver injury and fibrosis was accompanied by a significant induction of PDE4A, B, and D expression and activity. Treatment with the PDE4-specific inhibitor rolipram significantly decreased liver PDE4 activity, hepatic inflammatory and profibrotic cytokine expression, injury, and fibrosis. At the cellular level, in relevance to endotoxemia and inflammatory cytokine production, PDE4B was observed to play a major regulatory role in the LPS-inducible tumor necrosis factor (TNF) production by isolated Kupffer cells. Moreover, PDE4 expression was also involved in the in vitro activation and transdifferentiation of isolated hepatic stellate cells (HSCs). Particularly, PDE4A, B, and D upregulation preceded induction of the HSC activation marker ?-smooth muscle actin (?-SMA). In vitro treatment of HSCs with rolipram effectively attenuated ?-SMA, collagen expression, and accompanying morphologic changes. Overall, these data strongly suggest that upregulation of PDE4 expression during cholestatic liver injury plays a potential pathogenic role in the development of inflammation, injury, and fibrosis. PMID:23887098

Gobejishvili, Leila; Barve, Shirish; Breitkopf-Heinlein, Katja; Li, Yan; Zhang, JingWen; Avila, Diana V; Dooley, Steven; McClain, Craig J

2013-10-01

304

Caspase Dependent Programmed Cell Death in Developing Embryos: A Potential Target for Therapeutic Intervention against Pathogenic Nematodes  

PubMed Central

Background Successful embryogenesis is a critical rate limiting step for the survival and transmission of parasitic worms as well as pathology mediated by them. Hence, blockage of this important process through therapeutic induction of apoptosis in their embryonic stages offers promise for developing effective anti-parasitic measures against these extra cellular parasites. However, unlike in the case of protozoan parasites, induction of apoptosis as a therapeutic approach is yet to be explored against metazoan helminth parasites. Methodology/Principal Findings For the first time, here we developed and evaluated flow cytometry based assays to assess several conserved features of apoptosis in developing embryos of a pathogenic filarial nematode Setaria digitata, in-vitro as well as ex-vivo. We validated programmed cell death in developing embryos by using immuno-fluorescence microscopy and scoring expression profile of nematode specific proteins related to apoptosis [e.g. CED-3, CED-4 and CED-9]. Mechanistically, apoptotic death of embryonic stages was found to be a caspase dependent phenomenon mediated primarily through induction of intracellular ROS. The apoptogenicity of some pharmacological compounds viz. DEC, Chloroquine, Primaquine and Curcumin were also evaluated. Curcumin was found to be the most effective pharmacological agent followed by Primaquine while Chloroquine displayed minimal effect and DEC had no demonstrable effect. Further, demonstration of induction of apoptosis in embryonic stages by lipid peroxidation products [molecules commonly associated with inflammatory responses in filarial disease] and demonstration of in-situ apoptosis of developing embryos in adult parasites in a natural bovine model of filariasis have offered a framework to understand anti-fecundity host immunity operational against parasitic helminths. Conclusions/Significance Our observations have revealed for the first time, that induction of apoptosis in developing embryos can be a potential approach for therapeutic intervention against pathogenic nematodes and flow cytometry can be used to address different issues of biological importance during embryogenesis of parasitic worms.

Mohapatra, Alok Das; Kumar, Sunil; Satapathy, Ashok Kumar; Ravindran, Balachandran

2011-01-01

305

Genome sequencing of multidrug resistant novel Clostridium sp. BL8 reveals its potential for pathogenicity  

PubMed Central

Background The human gut microbiome is important for maintaining the health status of the host. Clostridia are key members of the human gut microbiome, carrying out several important functions in the gut environment. Hence understanding the role of different Clostridium species isolated from human gut is essential. The present study was aimed at investigating the role of novel Clostridium sp. isolate BL8 in human gut using genome sequencing as a tool. Findings The genome analysis of Clostridium sp. BL8 showed the presence of several adaptive features like bile resistance, presence of sensory and regulatory systems, presence of oxidative stress managing systems and presence of membrane transport systems. The genome of Clostridium sp. BL8 consists of a wide variety of virulence factors like phospholipase C (alpha toxin), hemolysin, aureolysin and exfoliative toxin A, as well as adhesion factors, proteases, Type IV secretion system and antibiotic resistance genes. In vitro antibiotic sensitivity testing showed that Clostridium sp. BL8 was resistant to 11 different tested antibiotics belonging to 6 different classes. The cell cytotoxicity assay confirmed the cytotoxic effect of Clostridium sp. BL8 cells, which killed 40% of the Vero cells after 4 hrs of incubation. Conclusions Clostridium sp. BL8 has adapted for survival in human gut environment, with presence of different adaptive features. The presence of several virulence factors and cell cytotoxic activity indicate that Clostridium sp. BL8 has a potential to cause infections in humans, however further in vivo studies are necessary to ascertain this fact.

2014-01-01

306

IL-4R? on CD4+ T cells plays a pathogenic role in respiratory syncytial virus reinfection in mice infected initially as neonates.  

PubMed

RSV is the major cause of severe bronchiolitis in infants, and severe bronchiolitis as a result of RSV is associated with subsequent asthma development. A biased Th2 immune response is thought to be responsible for neonatal RSV pathogenesis; however, molecular mechanisms remain elusive. Our data demonstrate, for the first time, that IL-4R? is up-regulated in vitro on human CD4(+) T cells from cord blood following RSV stimulation and in vivo on mouse pulmonary CD4(+) T cells upon reinfection of mice, initially infected as neonates. Th cell-specific deletion of Il4ra attenuated Th2 responses and abolished the immunopathophysiology upon reinfection, including airway hyper-reactivity, eosinophilia, and mucus hyperproduction in mice infected initially as neonates. These findings support a pathogenic role for IL-4R? on Th cells following RSV reinfection of mice initially infected as neonates; more importantly, our data from human cells suggest that the same mechanism occurs in humans. PMID:23543769

You, Dahui; Marr, Nico; Saravia, Jordy; Shrestha, Bishwas; Lee, Greg I; Turvey, Stuart E; Brombacher, Frank; Herbert, De'Broski R; Cormier, Stephania A

2013-06-01

307

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

308

Enhanced infectivity of H5N1 highly pathogenic avian influenza (HPAI) virus in pig ex vivo respiratory tract organ cultures following adaptation by in vitro passage.  

PubMed

Pigs are thought to play a role in the adaptation of avian influenza (AI) viruses to mammalian hosts. To better understand this mechanism and to identify key mutations two highly pathogenic AI (HPAI) viruses (H5N1 and H7N7) were grown in pig cells, To mimic the pressure of an immune response, these viruses were grown in the presence of antiserum to the homologous virus or porcine IFN-?. Mutations were identified in both viruses grown in vitro in the presence and absence of antisera or IFN-? and included the PB2 mutations, E627K or 627E,D701N, described previously as requirements for the adaptation of AI viruses to mammalian species. Additional mutations were also identified in PB1, HA, NP and M genes for viruses passaged in the presence of immune pressure. The infectivity of these viruses was then assessed using ex vivo pig bronchi and lung organ cultures. For lung explants, higher levels of virus were detected in organ cultures infected with H5N1 HPAI viruses passaged in pig cell lines regardless of the presence or absence of homologous antisera or IFN-? when compared with the wild-type parental viruses. No infection was observed for any of the H7N7 HPAI viruses. These results suggest that the mutations identified in H5N1 HPAI viruses may provide a replication or infection advantage in pigs in vivo and that pigs may continue to play an important role in the ecology of influenza A viruses including those of avian origin. PMID:24050997

Londt, Brandon Z; Brookes, Sharon M; Nash, Bethany J; Núñez, Alejandro; Kelly, Michael D; Garçon, Fanny; Graham, Simon P; Brown, Ian H

2013-12-26

309

Injury of respiratory epithelium.  

PubMed Central

The large surface area provided by the respiratory tract epithelium of humans for exposure to microbial agents and toxic substances in the environment makes this organ system very vulnerable but a good early indicator of adverse health effects. However, the complexity of pulmonary defense mechanisms complicates definition of the interactive effects of pollutants and infectious agents. Tracheal organ culture has been utilized to maintain organized, differentiated respiratory epithelium in vitro. This model system permits the exposure of respiratory epithelium to injurious agents in an easily visualized and controlled environment. Effects of individual toxin and/or infectious agents may be examined without the involvement of most host defenses and unwanted secondary microbial invaders which hamper interpretation of in vivo model studies. Further, elements of host immune response, pharmacologic agents and the like may be added selectively if desired. A body of information is being developed on specialized respiratory cell injury by various common pathogenic agents--including respiratory syncytial virus, parainfluenza virus type 3, Bordetella pertussis and Mycoplasma pneumoniae--through studies in tracheal organ cultures. These agents injure specialized epithelial cells in different ways, providing a spectrum of changes against which the added effects of toxic substances could be evaluated at the cellular and subcellular levels. Information on the pathogenesis of infectious/toxic injury could suggest new directions for human health research and for means to benefit the human host.

Collier, A M

1980-01-01

310

Pathogens and atherosclerosis: update on the potential contribution of multiple infectious organisms to the pathogenesis of atherosclerosis.  

PubMed

It is currently unclear what causes the chronic inflammation within atherosclerotic plaques. One emerging paradigm suggests that infection with bacteria and/or viruses can contribute to the pathogenesis of atherosclerosis either via direct infection of vascular cells or via the indirect effects of cytokines or acute phase proteins induced by infection at non-vascular sites. This paradigm has been supported by multiple epidemiological studies that have established positive associations between the risk of cardiovascular disease morbidity and mortality and markers of infection. It has also been supported by experimental studies showing an acceleration of the development of atherosclerosis following infection of hyperlipidaemic animal models. There are now a large number of different infectious agents that have been linked with an increased risk of cardiovascular disease. These include: Chlamydia pneumoniae, Porphyromonas gingivalis, Helicobacter pylori , influenza A virus, hepatitis C virus, cytomegalovirus, and human immunodeficiency virus. However, there are significant differences in the strength of the data supporting their association with cardiovascular disease pathogenesis. In some cases, the infectious agents are found within the plaques and viable organisms can be isolated suggesting a direct effect. In other cases, the association is entirely based on biomarkers. In the following review, we evaluate the strength of the data for individual or groups of pathogens with regard to atherosclerosis pathogenesis and their potential contribution by direct or indirect mechanisms and discuss whether the established associations are supportive of the infectious disease paradigm. We also discuss the failure of antibiotic trials and the question of persistent infection. PMID:22012133

Rosenfeld, M E; Campbell, L A

2011-11-01

311

Probiotic yeasts: Anti-inflammatory potential of various non-pathogenic strains in experimental colitis in mice  

PubMed Central

AIM: To evaluate the in vitro immunomodulation capacity of various non-pathogenic yeast strains and to investigate the ability of some of these food grade yeasts to prevent experimental colitis in mice. METHODS: In vitro immunomodulation was assessed by measuring cytokines [interleukin (IL)-12p70, IL-10, tumor necrosis factor and interferon ?] released by human peripheral blood mononuclear cells after 24 h stimulation with 6 live yeast strains (Saccharomyces ssp.) and with bacterial reference strains. A murine model of acute 2-4-6-trinitrobenzene sulfonic acid (TNBS)-colitis was next used to evaluate the distinct prophylactic protective capacities of three yeast strains compared with the performance of prednisolone treatment. RESULTS: The six yeast strains all showed similar non-discriminating anti-inflammatory potential when tested on immunocompetent cells in vitro. However, although they exhibited similar colonization patterns in vivo, some yeast strains showed significant anti-inflammatory activities in the TNBS-induced colitis model, whereas others had weaker or no preventive effect at all, as evidenced by colitis markers (body-weight loss, macroscopic and histological scores, myeloperoxidase activities and blood inflammatory markers). CONCLUSION: A careful selection of strains is required among the biodiversity of yeasts for specific clinical studies, including applications in inflammatory bowel disease and other therapeutic uses.

Foligne, Benoit; Dewulf, Joelle; Vandekerckove, Pascal; Pignede, Georges; Pot, Bruno

2010-01-01

312

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

313

Pathogenicity and cytadherence of Mycoplasma imitans in chicken and duck embryo tracheal organ cultures.  

PubMed Central

Two strains of the avian organism Mycoplasma imitans were examined for pathogenicity and cytadherence in chicken and duck embryo tracheal organ cultures, and a virulent strain of the related pathogen Mycoplasma gallisepticum was included for comparison. All consistently cause ciliostasis in tracheal explants from both hosts, and examination of infected tissues by immunofluorescence and transmission electron microscopy demonstrated that M. imitans proliferated on the epithelial surface and adhered to the respiratory epithelium by means of its terminal tip structure in the same manner as M. gallisepticum. These observations endorse the striking phenotypic similarities between M. imitans and M. gallisepticum and suggest that M. imitans may have pathogenic potential in vivo.

Abdul-Wahab, O M; Ross, G; Bradbury, J M

1996-01-01

314

Antifungal potential of Indian medicinal plants  

Microsoft Academic Search

Fourteen Indian plants, selected based on their use in respiratory and other disorders in traditional systems of medicine, were analyzed for their potential activity against fungi. The antifungal activity was investigated by disc diffusion, microbroth dilution and percent spore germination inhibition tests against pathogenic Aspergilli. Methanolic extracts of Solanum xanthocarpum and Datura metel inhibited the growth of Aspergillus fumigatus, A.

Rajesh Dabur; H. Singh; A. K. Chhillar; M. Ali; G. L. Sharma

2004-01-01

315

Inflammatory responses to Respiratory Syncytial Virus (RSV) infection and the development of immunomodulatory pharmacotherapeutics  

PubMed Central

Respiratory syncytial virus (RSV; Family Paramyxoviridae, Genus Pneumovirus) is a major respiratory pathogen of infants and children and an emerging pathogen of the elderly. Current management of RSV disease includes monoclonal antibody prophylaxis for infants identified as high risk and supportive care for those with active infection; there is no vaccine, although several are under study. In this manuscript, we review published findings from human autopsy studies, as well as experiments that focus on human clinical samples and mouse models of acute pneumovirus infection that elucidate basic principles of disease pathogenesis. Consideration of these data suggests that the inflammatory responses to RSV and related pneumovirus pathogens can be strong, persistent, and beyond the control of conventional antiviral and anti-inflammatory therapies, and can have profound negative consequences to the host. From this perspective, we consider the case for specific immunomodulatory strategies that may have the potential to alleviate some of the more serious sequelae of this disease.

Rosenberg, Helene F.; Domachowske, Joseph B.

2012-01-01

316

Comparison of the Pathogenic Potentials of Environmental and Clinical Vibrio parahaemolyticus Strains Indicates a Role for Temperature Regulation in Virulence? †  

PubMed Central

Although the presence of pathogenic Vibrio spp. in estuarine environments of northern New England has been known for some time (C. H. Bartley and L. W. Slanetz, Appl. Microbiol. 21: 965-966, 1971, and K. R. O'Neil, S. H. Jones, and D. J. Grimes, FEMS Microbiol. Lett. 60:163-167, 1990), their virulence and the relative threat they may pose to human health has yet to be evaluated. In this study, the virulence potential of 33 Vibrio parahaemolyticus isolates collected from the Great Bay Estuary of New Hampshire was assessed in comparison to that of clinical strains. The environmental isolates lack thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH), which are encoded by tdh and trh, respectively. Though not hemolytic, they do possess putative virulence factors, such type III secretion system 1, and are highly cytotoxic to human gastrointestinal cells. The expression of known and putative virulence-associated traits, including hemolysin, protease, motility, biofilm formation, and cytotoxicity, by clinical reference isolates correlated with increased temperature from 28°C to 37°C. In contrast, the environmental isolates did not induce their putative virulence-associated traits in response to a temperature of 37°C. We further identified a significant correlation between hemolytic activity and growth phase among clinical strains, whereby hemolysin production decreases with increasing cell density. The introduction of a tdh::gfp promoter fusion into the environmental strains revealed that they regulate this virulence-associated gene appropriately in response to temperature, indicating that their existing regulatory mechanisms are primed to manage newly acquired virulence genes.

Mahoney, Jennifer C.; Gerding, Matthew J.; Jones, Stephen H.; Whistler, Cheryl A.

2010-01-01

317

Comparison of the pathogenic potentials of environmental and clinical vibrio parahaemolyticus strains indicates a role for temperature regulation in virulence.  

PubMed

Although the presence of pathogenic Vibrio spp. in estuarine environments of northern New England has been known for some time (C. H. Bartley and L. W. Slanetz, Appl. Microbiol. 21: 965-966, 1971, and K. R. O'Neil, S. H. Jones, and D. J. Grimes, FEMS Microbiol. Lett. 60:163-167, 1990), their virulence and the relative threat they may pose to human health has yet to be evaluated. In this study, the virulence potential of 33 Vibrio parahaemolyticus isolates collected from the Great Bay Estuary of New Hampshire was assessed in comparison to that of clinical strains. The environmental isolates lack thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH), which are encoded by tdh and trh, respectively. Though not hemolytic, they do possess putative virulence factors, such type III secretion system 1, and are highly cytotoxic to human gastrointestinal cells. The expression of known and putative virulence-associated traits, including hemolysin, protease, motility, biofilm formation, and cytotoxicity, by clinical reference isolates correlated with increased temperature from 28°C to 37°C. In contrast, the environmental isolates did not induce their putative virulence-associated traits in response to a temperature of 37°C. We further identified a significant correlation between hemolytic activity and growth phase among clinical strains, whereby hemolysin production decreases with increasing cell density. The introduction of a tdh::gfp promoter fusion into the environmental strains revealed that they regulate this virulence-associated gene appropriately in response to temperature, indicating that their existing regulatory mechanisms are primed to manage newly acquired virulence genes. PMID:20889774

Mahoney, Jennifer C; Gerding, Matthew J; Jones, Stephen H; Whistler, Cheryl A

2010-11-01

318

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

PubMed

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

2014-08-01

319

The Challenge of Respiratory Virus Infections in Hematopoietic Cell Transplant Recipients  

PubMed Central

Respiratory virus infections in hematopoietic cell transplant (HCT) recipients are a major cause of morbidity and mortality. While respiratory syncytial virus (RSV), human metapneumonvirus, parainfluenzaviruses, and influenza viruses are well known for their potential to cause fatal pneumonia, information is emerging only recently on the significance of the newly discovered viruses such as human coronaviruses NL63 and HKU1, and human bocavirus. Lymphopenia seems to be the most recent risk factors for progression to lower respiratory tract disease. Airflow obstruction is another complication of respiratory virus infections after HCT, and data to date indicate this complication may occur following parainfluenza virus and RSV infection. Infection control procedures are key for prevention. Unfortunately, there are no randomized treatment studies, which make the interpretation of the literature on interventions difficult. This article reviews the spectrum of pathogens, epidemiology, risk factors and clinical manifestations of infection, as well as recent advances in diagnostic and clinical management.

Boeckh, Michael

2009-01-01

320

Respiratory protection.  

PubMed

Respiratory protection is used as a method of protecting individuals from inhaling harmful airborne contaminants and in some cases to supply them with breathable air in oxygen-deficient environments. This article focuses on the use and types of personal respiratory protection (respirators) worn by individuals at workplaces where airborne hazardous contaminants may exist. Respirators are increasingly also being used in nonindustrial settings such as health care facilities, as concerns regarding infectious epidemics and terrorist threats grow. Pulmonologists and other clinicians should understand fundamental issues regarding respiratory protection against airborne contaminants and the use of respirators. PMID:23153616

Cohen, Howard J; Birkner, Jeffrey S

2012-12-01

321

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.

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

322

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

323

Benthic respiratory potential with relation to sedimentary carbon quality in seagrass beds and oyster parks in the tidal flats of Arcachon Bay, France  

NASA Astrophysics Data System (ADS)

Relationships between sedimentary organic carbon quality and the benthic response were checked in tidal sediment of Arcachon Bay, France. Pigment and easily extractable macromolecular contents were used as indicators of the quality of particulate organic carbon (POC) while respiratory electron transport system (ETS) activity was chosen as an indicator for benthic response. The study was carried out in seven stations representing strongly different facies; these stations were sampled seasonally. Total ETS-activity includes the respiratory potential of various benthic compartments (phytobenthos, meiofauna, protozoa and bacteria). The importance of each of these components was calculated using conversion factors between ETS and biomass parameters. It was shown that ETS-activity due to phytobenthos was relatively high (up to 87% of total ETS) in stations under intense hydrodynamic conditions, but low (less than 23%) in the most sheltered stations. The impact of meiofauna was very low in all stations (less than 15% of heterotrophic ETS). Total and heterotrophic ETS activities were highly correlated with either POC, macromolecular content or protein. The slopes of the curves were compared with the ratios known for living organisms. The ETS/POC ratio in sediment was much lower than that in living matter while ETS/macromolecules and especially ETS/protein in sediment were of the same order as that in living material. We conclude that the degradable organic matter, (i.e. easily extractable biopolymers) could be mainly biomass and that detrital degradable molecules could be rapidly incorporated in biomass and not accumulate.

Relexans, Jean-Claude; Etcheber, Henri; Castel, Jacques; Escaravage, Vincent; Auby, Isabelle

1992-02-01

324

Respiratory System  

NSDL National Science Digital Library

The purpose, components, and functions of the respiratory system are presented in this learning through disussion and visualizations. Participants learn about the nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and alveoli.

Bidlack, Jim

325

Pathogen survival in the external environment and the evolution of virulence.  

PubMed

Recent studies have provided evolutionary explanations for much of the variation in mortality among human infectious diseases. One gap in this knowledge concerns respiratory tract pathogens transmitted from person to person by direct contact or through environmental contamination. The sit-and-wait hypothesis predicts that virulence should be positively correlated with durability in the external environment because high durability reduces the dependence of transmission on host mobility. Reviewing the epidemiological and medical literature, we confirm this prediction for respiratory tract pathogens of humans. Our results clearly distinguish a high-virulence high-survival group of variola (smallpox) virus, Mycobacterium tuberculosis, Cornynebacterium diphtheriae, Bordetella pertussis, Streptococcus pneumoniae, and influenza virus (where all pathogens have a mean percent mortality > or = 0.01% and mean survival time >10 days) from a low-virulence low-survival group containing ten other pathogens. The correlation between virulence and durability explains three to four times of magnitude of difference in mean percent mortality and mean survival time, using both across-species and phylogenetically controlled analyses. Our findings bear on several areas of active research and public health policy: (1) many pathogens used in the biological control of insects are potential sit-and-wait pathogens as they combine three attributes that are advantageous for pest control: high virulence, long durability after application, and host specificity; (2) emerging pathogens such as the 'hospital superbug' methicillin-resistant Staphylococcus aureus (MRSA) and potential bioweapons pathogens such as smallpox virus and anthrax that are particularly dangerous can be discerned by quantifying their durability; (3) hospital settings and the AIDS pandemic may provide footholds for emerging sit-and-wait pathogens; and (4) studies on food-borne and insect pathogens point to future research considering the potential evolutionary trade-offs and genetic linkages between virulence and durability. PMID:15682873

Walther, Bruno A; Ewald, Paul W

2004-11-01

326

A survey of the fecal bacteria of bison (Bison bison) for potential pathogens and antimicrobial susceptibility of bison-origin E. coli  

PubMed Central

An observational study determined the normal fecal bacterial flora of clinically healthy bison, detected the presence of common potential zoonotic pathogens, and determined the antimicrobial susceptibility of isolated E. coli strains. Ninety-six fecal samples from 10 captive herds were cultured for aerobic, anaerobic, facultative, and microaerophillic bacteria. Nineteen major genera of gram-positive and 8 genera of gram-negative bacteria were identified. Salmonella spp. were not detected but some of the isolated bacteria are potential gastrointestinal pathogens. Minimum inhibitory concentrations (MIC) of 24 antimicrobials were determined for the E. coli isolated. Nearly all were susceptible to 23 of the 24 antimicrobials but there was a reduced susceptibility to sulphonamide. There were fewer resistant strains than were reported in recent studies of generic E. coli from cattle living in the same area.

Woodbury, Murray R.; Chirino-Trejo, Manuel

2011-01-01

327

Characterization of small ruminant lentivirus A4 subtype isolates and assessment of their pathogenic potential in naturally infected goats  

PubMed Central

Background Small ruminant lentiviruses escaping efficient serological detection are still circulating in Swiss goats in spite of a long eradication campaign that essentially eliminated clinical cases of caprine arthritis encephalitis in the country. This strongly suggests that the circulating viruses are avirulent for goats. To test this hypothesis, we isolated circulating viruses from naturally infected animals and tested the in vitro and in vivo characteristics of these field isolates. Methods Viruses were isolated from primary macrophage cultures. The presence of lentiviruses in the culture supernatants was monitored by reverse transcriptase assay. Isolates were passaged in different cells and their cytopathogenic effects monitored by microscopy. Proviral load was quantified by real-time PCR using customized primer and probes. Statistical analysis comprised Analysis of Variance and Bonferroni Multiple Comparison Test. Results The isolated viruses belonged to the small ruminant lentiviruses A4 subtype that appears to be prominent in Switzerland. The 4 isolates replicated very efficiently in macrophages, displaying heterogeneous phenotypes, with two isolates showing a pronounced cytopathogenicity for these cells. By contrast, all 4 isolates had a poor replication capacity in goat and sheep fibroblasts. The proviral loads in the peripheral blood and, in particular, in the mammary gland were surprisingly high compared to previous observations. Nevertheless, these viruses appear to be of low virulence for goats except for the mammary gland were histopathological changes were observed. Conclusions Small ruminant lentiviruses continue to circulate in Switzerland despite a long and expensive caprine arthritis encephalitis virus eradication campaign. We isolated 4 of these lentiviruses and confirmed their phylogenetic association with the prominent A4 subtype. The pathological and histopathological analysis of the infected animals supported the hypothesis that these A4 viruses are of low pathogenicity for goats, with, however, a caveat about the potentially detrimental effects on the mammary gland. Moreover, the high proviral load detected indicates that the immune system of the animals cannot control the infection and this, combined with the phenotypic plasticity observed in vitro, strongly argues in favour of a continuous and precise monitoring of these SRLV to avoid the risk of jeopardizing a long eradication campaign.

2014-01-01

328

Misdiagnosis of spider bites: bacterial associates, mechanical pathogen transfer, and hemolytic potential of venom from the hobo spider, Tegenaria agrestis (Araneae: Agelenidae).  

PubMed

The European spider Tegenaria agrestis (Walckenaer) (hobo spider) has been implicated as a spider of medical importance in the Pacific Northwest since its introduction in the late 1980s. Studies have indicated that the hobo spider causes necrotic tissue lesions through hemolytic venom or through the transfer of pathogenic bacteria introduced by its bite. Bacterial infections are often diagnosed as spider bites, in particular the pathogenic bacteria methicillin-resistant Staphylococcus aureus (MRSA). This study examines three aspects of the potential medical importance of hobo spiders in part of its introduced range, Washington State. First, the bacterial diversity of the spider was surveyed using a polymerase chain reaction-based assay to determine whether the spider carries any pathogenic bacteria. Second, an experiment was conducted to determine the ability of the spiders to transfer MRSA. Third, the venom was evaluated to assess the hemolytic activity. We found 10 genera of ubiquitous bacteria on the exterior surface of the spiders. In addition, none of the spiders exposed to MRSA transferred this pathogen. Finally, the hemolytic venom assay corroborates previous studies that found hobo spider venom was not deleterious to vertebrate red blood cells. PMID:21485377

Gaver-Wainwright, Melissa M; Zack, Richard S; Foradori, Matthew J; Lavine, Laura Corley

2011-03-01

329

Burden of respiratory viruses in patients with acute respiratory failure.  

PubMed

Respiratory viruses (RVs) are ubiquitous pathogens that represent a major cause of community-acquired pneumonia and chronic pulmonary diseases exacerbations. However, their contribution to acute respiratory failure events requiring intensive care unit admission in the era of rapid multiplex molecular assay deserves further evaluation. This study investigated the burden of viral infections in non immunocompromised patients admitted to the intensive care unit for acute respiratory failure using a multiplex molecular assay. Patients were investigated for RVs using immunofluoresence testing and a commercial multiplex molecular assay, and for bacteria using conventional culture. Half the patients (34/70, 49%) had a documented RVs infection. No other pathogen was found in 24 (71%) patients. Viral infection was detected more frequently in patients with obstructive respiratory diseases (64% vs. 29%; P?=?0.0075). Multiplex molecular assay should be considered as an usefull diagnostic tool in patients admitted to the intensive care unit with acute respiratory failure, especially those with acute exacerbations of chronic obstructive pulmonary disease and asthma. PMID:24108695

Schnell, David; Gits-Muselli, Maud; Canet, Emmanuel; Lemiale, Virginie; Schlemmer, Benoît; Simon, François; Azoulay, Elie; Legoff, Jérôme

2014-07-01

330

Zoonotic mosquito-borne flaviviruses: Worldwide presence of agents with proven pathogenicity and potential candidates of future emerging diseases  

Microsoft Academic Search

An update on the mosquito-borne flavivirus species including certain subtypes, as listed in the Eighth Report of the International Committee on Taxonomy of Viruses, is given. Special emphasis is placed on viruses which have been shown to cause diseases in animals, and viruses for which no pathogenicity has been proven yet. Several recent examples (Usutu virus and lineage-2 West Nile

H. Weissenböck; Z. Hubálek; T. Bakonyi; N. Nowotny

2010-01-01

331

Equal virulence of rhinovirus and respiratory syncytial virus in infants hospitalized for lower respiratory tract infection.  

PubMed

Respiratory syncytial virus (RSV) and rhinovirus (RV) are predominant viruses associated with lower respiratory tract infection in infants. We compared the symptoms of lower respiratory tract infection caused by RSV and RV in hospitalized infants. RV showed the same symptoms as RSV, so on clinical grounds, no difference can be made between these pathogens. No relation between polymerase chain reaction cycle threshold value and length of hospital stay was found. PMID:21909047

Van Leeuwen, Janneke C; Goossens, Loes K; Hendrix, Ron M G R; Van Der Palen, Job; Lusthusz, Anneloes; Thio, Boony J

2012-01-01

332

Respiratory virus infections among children in South China.  

PubMed

Acute respiratory tract infection is an important cause of morbidity and mortality with a worldwide disease burden. This study aimed to determine the prevalence and clinical characteristics of children with viral-induced acute respiratory tract infection, in Southern China. Nasopharyngeal aspirate samples from 1,980 pediatric patients with suspected acute respiratory tract infection, and 82 samples from healthy subject controls were collected for routine examination at the Second Affiliated Hospital of Shantou University Medical College, from October 2007 to August 2011. Specimens were tested by multiplex polymerase chain reaction (mPCR). At least one or more viruses were detected from 1,087 samples (54.9%). These included laboratory confirmations for 446 respiratory syncytial virus (RSV), 386 influenza virus A (FluA), 315 human rhinovirus (HRV), 135 human bocavirus (HBoV), 119 Parainfluenza virus 3 (PIV3), 82 Parainfluenza virus 1 (PIV1), 66 adenovirus (ADV), 53 WU polyomavirus (WUPyV), 52 human metapneumovirus (hMPV), and 29 influenza virus B (FluB) samples. Samples from healthy subjects were negative for any virus. Of the patients with positive specimens, 107 (9.8%) were admitted to pediatric intensive care unit (PICU). Co-infection with at least two of the viral pathogens under study was observed in 325 of the 1,980 patients (16.4% of the total number of cases). These findings may help in the diagnosis of viral infections of the respiratory tract in children, and help to consider current and potential therapeutic approaches for the treatment of acute respiratory tract infection, and further respiratory complications. PMID:24619492

Cai, Xiao-Ying; Wang, Qiong; Lin, Guang-Yu; Cai, Zhi-Wei; Lin, Chuang-Xing; Chen, Pai-Zhen; Zhou, Xiao-Hua; Xie, Jin-Chun; Lu, Xue-Dong

2014-07-01

333

Respiratory virus disease in Malaysian children: a serological study*  

PubMed Central

Paired sera from 101 Malaysian children aged up to 10 years and suffering from respiratory illnesses were examined serologically for evidence of respiratory viral infections. Of these children, 32.6% showed rising antibody titres for one or more of the test agents. Respiratory syncytial virus appeared to be the main respiratory pathogen involved, followed by Mycoplasma pneumoniae, parainfluenza viruses, adenoviruses, and influenza A virus. These findings are generally similar to those reported by others in temperate and tropical countries.

Ong, S. B.; Lam, K. L.; Lam, S. K.

1975-01-01

334

Respiratory system: applied pharmacology  

Microsoft Academic Search

Manipulation of respiratory physiology by pharmacological intervention is a significant role of the anaesthetist and intensivist. Successful use of these various agents requires a thorough understanding of their mechanisms of actions, potential side effects and limitations. These interventions involve changes in airway calibre, secretions and sensitivity of the airway to noxious stimuli. Other agents act to inhibit the depressant effect

Daniel J Saul; Jonathan B Kendall

335

Emerging and reemerging pathogens.  

PubMed

From 1973 to 1995, 29 new and reemerging pathogenic microbes were recognized. However, in discussions about emerging infectious diseases, the focus is often on the clinical effects of the host-parasite relationship, rather than the examination of the biology of the pathogen. Many of what we refer to as emerging diseases are characterized better as 'diseases of human progress'. Thus, the aerosolization of water has played an important role in the emergence of Legionella pneumophila infections. New diseases are superimposed on endemic diseases such as diarrhoeal diseases, malaria and tuberculosis. In addition, many pathogens are becoming increasingly resistant to standard antimicrobial drugs, making treatment difficult and in some cases impossible. We summarize our experience on emerging parasitic diseases (primary amoebic meningoencephalitis, respiratory cryptosporidiosis, and diplogonoporiasis), and selected problems of bacterial resistance (MDR tuberculosis caused by Mycobacterium bovis and macrolide-resistance mechanisms of Streptococcus pneumoniae and S. pyogenes). PMID:11091058

Gomez-Lus, R; Clavel, A; Castillo, J; Seral, C; Rubio, C

2000-11-01

336

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.

Liu, Yang; Keller, Irene; Heckel, Gerald

2011-01-01

337

Pathogenicity of the family Legionellaceae.  

PubMed

The Legionellae are Gram-negative bacteria able to survive and replicate in a wide range of protozoan hosts in natural environments, but they also occur in man-made aquatic systems, which are the major source of infection. After transmission to humans via aerosols, Legionella spp. can cause pneumonia (Legionnaires' disease) or influenza-like respiratory infections (Pontiac fever). In children, Legionnaires' disease is uncommon and is mainly diagnosed in children with immunosuppression. The clinical picture of Legionella pneumonia does not allow differentiation from pneumonia caused by others pathogens. The key to diagnosis is performing appropriate microbiological testing. The clinical presentation and the natural course of Legionnaires' disease in children are not clear due to an insufficient number of samples, but morbidity and mortality caused by this infection are extremely high. The mortality rate for legionellosis depends on the promptness of an appropriate antibiotic therapy. Fluoroquinolones are the most efficacious drugs against Legionella. A combination of these drugs with macrolides seems to be promising in the treatment of immunosuppressed patients and individuals with severe legionellosis. Although all Legionella species are considered potentially pathogenic for humans, Legionella pneumophila is the etiological agent responsible for most reported cases of community-acquired and nosocomial legionellosis. PMID:19578813

Palusi?ska-Szysz, Marta; Cendrowska-Pinkosz, Monika

2009-01-01

338

Fungal pathogens of Euphorbia heterophylla and E. hirta in Brazil and their potential as weed biocontrol agents  

Microsoft Academic Search

A two-year survey of the fungi associated with two important congeneric pantropical weeds, Euphorbia heterophylla and E. hirta, was conducted in part of their native range in southern Brazil. Sampling was concentrated mainly in Rio de Janeiro State\\u000a and ten species were identified as pathogens of these weeds. Two taxa, Botrytis ricini and Uromyces euphorbiae, were common to both weed

Robert W. Barreto; Harry C. Evans

1998-01-01

339

Pathogenic potential of vibriophages against an experimental infection with Vibrio cholerae O1 in the RITARD model  

Microsoft Academic Search

Cholera continues to be an important public health problem in developing countries, including India. This study concerns the feasibility of possible exploitation of bacteriophages as a biocontrol agent to eliminate the pathogen Vibrio cholerae from the gut using the removable intestinal tie–adult rabbit diarrhoea (RITARD) model. A control rabbit challenged with 109 colony-forming units (CFU)\\/mL of V. cholerae MAK 757

Tushar Suvra Bhowmick; Hemanta Koley; Mayukh Das; Dhira Rani Saha; B. L. Sarkar

2009-01-01

340

High rate of Simkania negevensis among Canadian inuit infants hospitalized with lower respiratory tract infections.  

PubMed

To determine the prevalence of Simkania negevensis in causing pulmonary infections in children, nasopharyngeal washes were obtained from 22 infants hospitalized with acute bronchiolitis in the Baffin Island, Canada. 14 (63.6%) were positive for S. negevensis. Mixed infections with other respiratory viruses were common. All patients recovered without specific antibiotic treatment. Even though a high prevalence of S. negevensis was found, this organism may potentially well be an opportunistic agent rather than a true pathogen. PMID:14514154

Greenberg, David; Banerji, Anna; Friedman, Maureen G; Chiu, Cheng-Hsun; Kahane, Simona

2003-01-01

341

Advancing Respiratory Research  

PubMed Central

Respiratory diseases remain a major public health problem in the United States and worldwide, with increasing morbidity and mortality. Substantial progress has been made to advance understanding of the basic mechanisms of lung disease and to optimize clinical management of patients with a range of respiratory diseases. Despite this progress, our knowledge of how to predict disease prior to symptoms, improve disease definition and subclassification, and target novel and new treatments in a more personalized manner still remains inadequate. This article highlights several future opportunities and challenges related to genomics and molecular characterization of lung disease, lung injury and repair, translational lung research, the microbiome, and sleep and circadian biology as potential frontiers to advance progress in respiratory biology in health and disease.

2011-01-01

342

In-vitro renal epithelial cell infection reveals a viral kidney tropism as a potential mechanism for acute renal failure during Middle East Respiratory Syndrome (MERS) Coronavirus infection  

PubMed Central

Background The Middle East Respiratory Syndrome Coronavirus (MERS-CoV) causes symptoms similar to Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), yet involving an additional component of acute renal failure (ARF) according to several published case reports. Impairment of the kidney is not typically seen in Coronavirus infections. The role of kidney infection in MERS is not understood. Findings A systematic review of communicated and peer-reviewed case reports revealed differences in descriptions of kidney involvement in MERS versus SARS patients. In particular, ARF in MERS patients occurred considerably earlier after a median time to onset of 11 days (SD ±2,0 days) as opposed to 20 days for SARS, according to the literature. In-situ histological staining of the respective cellular receptors for MERS- and SARS-Coronavirus showed highly similar staining patterns with a focus of a receptor-specific signal in kidney epithelial cells. Comparative infection experiments with SARS- and MERS-CoV in primary human kidney cells versus primary human bronchial epithelial cells showed cytopathogenic infection only in kidney cells, and only if infected with MERS-CoV. Kidney epithelial cells produced almost 1000-fold more infectious MERS-CoV progeny than bronchial epithelial cells, while only a small difference was seen between cell types when infected with SARS-CoV. Conclusion Epidemiological studies should analyze kidney impairment and its characteristics in MERS-CoV. Virus replication in the kidney with potential shedding in urine might constitute a way of transmission, and could explain untraceable transmission chains leading to new cases. Individual patients might benefit from early induction of renoprotective treatment.

2013-01-01

343

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...

344

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.

Lenczewski, Melissa

345

Respiratory monitoring of neonatal resuscitation.  

PubMed

Video observations and recordings of respiratory signals from mannequin studies and delivery room (DR) resuscitations are described. This article discusses the uses of a respiratory function monitor (RFM) during training and resuscitations along with potential pitfalls and limitations. It adds objectivity to the clinical assessment. A respiratory function monitor provides real-time quantitative information including tidal volume and leak. It may be used to teach correct mask hold and positioning techniques during simulation-based mannequin. Examples demonstrating its potential usefulness during resuscitations are provided. However, further studies are needed to investigate whether it can help improve short-term and long-term outcomes. PMID:19776023

Schmölzer, Georg M; Kamlin, Omar C O F; Dawson, Jennifer A; te Pas, Arjan B; Morley, Colin J; Davis, Peter G

2010-07-01

346

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.

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

2012-01-01

347

COL4A1 and COL4A2 mutations and disease: insights into pathogenic mechanisms and potential therapeutic targets.  

PubMed

Heterotrimers composed of collagen type IV alpha 1 (COL4A1) and alpha 2 (COL4A2) constitute one of the most abundant components of nearly all basement membranes. Accordingly, mutations in COL4A1 or COL4A2 are pleiotropic and contribute to a broad spectrum of disorders, including myopathy, glaucoma and hemorrhagic stroke. Here, we summarize the contributions of COL4A1 and COL4A2 mutations in human disease, integrate knowledge gained from model organisms and evaluate the implications for pathogenic mechanisms and therapeutic approaches. PMID:22914737

Kuo, Debbie S; Labelle-Dumais, Cassandre; Gould, Douglas B

2012-10-15

348

Metabotropic glutamate receptors (mGluR5) activate transient receptor potential canonical channels to improve the regularity of the respiratory rhythm generated by the pre-Bötzinger complex in mice.  

PubMed

Metabotropic glutamate receptors (mGluRs) are hypothesized to play a key role in generating the central respiratory rhythm and other rhythmic activities driven by central pattern generators (e.g. locomotion). However, the functional role of mGluRs in rhythmic respiratory activity and many motor patterns is very poorly understood. Here, we used mouse respiratory brain-slice preparations containing the pre-Bötzinger complex (pre-BötC) to identify the role of group I mGluRs (mGluR1 and mGluR5) in respiratory rhythm generation. We found that activation of mGluR1/5 is not required for the pre-BötC to generate a respiratory rhythm. However, our data suggest that mGluR1 and mGluR5 differentially modulate the respiratory rhythm. Blocking endogenous mGluR5 activity with 2-Methyl-6-(phenylethynyl)pyridine (MPEP) decreases the inspiratory burst duration, burst area and frequency, whereas it increases the irregularity of the fictive eupneic inspiratory rhythm generated by the pre-BötC. In contrast, blocking mGluR1 reduces the frequency. Moreover, the mGluR1/5 agonist 3,5-dihydroxyphenylglycine increases the frequency and decreases the irregularity of the respiratory rhythm. Based on previous studies, we hypothesized that mGluR signaling decreases the irregularity of the respiratory rhythm by activating transient receptor potential canonical (TRPC) channels, which carry a non-specific cation current (ICAN). Indeed, 3,5-dihydroxyphenylglycine (DHPG) application reduces cycle-by-cycle variability and subsequent application of the TRPC channel blocker 1-[2-(4-methoxyphenyl)-2-[3-(4-methoxyphenyl)propoxy]ethyl]imidazole (SKF-96365) hydrochloride reverses this effect. Our data suggest that mGluR5 activation of ICAN-carrying TRPC channels plays an important role in governing the cycle-by-cycle variability of the respiratory rhythm. These data suggest that modulation of TRPC channels may correct irregular respiratory rhythms in some central neuronal diseases. PMID:22612431

Ben-Mabrouk, Faiza; Amos, Louella B; Tryba, Andrew K

2012-06-01

349

Transplantation-associated long-term immunosuppression promotes oral colonization by potentially opportunistic pathogens without impacting other members of the salivary bacteriome.  

PubMed

Solid-organ transplant recipients rely on pharmacological immunosuppression to prevent allograft rejection. The effect of such chronic immunosuppression on the microflora at mucosal surfaces is not known. We evaluated the salivary bacterial microbiome of 20 transplant recipients and 19 nonimmunosuppressed controls via 454 pyrosequencing of 16S rRNA gene amplicons. Alpha-diversity and global community structure did not differ between transplant and control subjects. However, principal coordinate analysis showed differences in community membership. Taxa more prevalent in transplant subjects included operational taxonomic units (OTUs) of potentially opportunistic Gammaproteobacteria such as Klebsiella pneumoniae, Pseudomonas fluorescens, Acinetobacter species, Vibrio species, Enterobacteriaceae species, and the genera Acinetobacter and Klebsiella. Transplant subjects also had increased proportions of Pseudomonas aeruginosa, Acinetobacter species, Enterobacteriaceae species, and Enterococcus faecalis, among other OTUs, while genera with increased proportions included Klebsiella, Acinetobacter, Staphylococcus, and Enterococcus. Furthermore, in transplant subjects, the dose of the immunosuppressant prednisone positively correlated with bacterial richness, while prednisone and mycophenolate mofetil doses positively correlated with the prevalence and proportions of transplant-associated taxa. Correlation network analysis of OTU relative abundance revealed a cluster containing potentially opportunistic pathogens as transplant associated. This cluster positively correlated with serum levels of C-reactive protein, suggesting a link between the resident flora at mucosal compartments and systemic inflammation. Network connectivity analysis revealed opportunistic pathogens as highly connected to each other and to common oral commensals, pointing to bacterial interactions that may influence colonization. This work demonstrates that immunosuppression aimed at limiting T-cell-mediated responses creates a more permissive oral environment for potentially opportunistic pathogens without affecting other members of the salivary bacteriome. PMID:23616410

Diaz, Patricia I; Hong, Bo-Young; Frias-Lopez, Jorge; Dupuy, Amanda K; Angeloni, Mark; Abusleme, Loreto; Terzi, Evimaria; Ioannidou, Effie; Strausbaugh, Linda D; Dongari-Bagtzoglou, Anna

2013-06-01

350

Recurrent Respiratory Papillomatosis: A Rare Chronic Disease, Difficult to Treat, with Potential to Lung Cancer Transformation: Apropos of Two Cases and a Brief Literature Review  

Microsoft Academic Search

Recurrent respiratory papillomatosis (RRP), which is caused exclusively by human papilloma virus (HPV), is a rare condition characterized by recurrent growth of benign papillomata in the respiratory tract. The papillomata can occur anywhere in the aerodigestive tract but most frequently in the larynx, affecting both children and adults. The management of this entity remains still challenging since no specific definitive

Stamatis Katsenos; Heinrich D. Becker

2011-01-01

351

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.

Cholewa, Grazyna; Krasowska, Ewelina; Chmielewska-Badora, Jolanta; Zwolinski, Jacek; Sobczak, Pawel

2013-01-01

352

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

...Potential To Pose a Serious Threat to Public Health; Public Hearing; Request for...potential to pose a serious threat to public health), as required under the Food...potential to pose a serious threat to public health, such as[:] (A)...

2012-11-16

353

A two-centre study for the evaluation and validation of an animal model for the assessment of the potential of small molecular weight chemicals to cause respiratory allergy.  

PubMed

This study evaluated a single intradermal injection model in the guinea pig with subsequent inhalation challenge and serological analysis as a method to predict the potential of chemicals to induce respiratory allergy. Four known respiratory allergens (trimellitic anhydride, diphenyl methane diisocyanate, phthalic anhydride and toluene diisocyanate (TDI)) were screened by two industrial research laboratories using this protocol. Dinitrochlorobenzene, a potent contact allergen, was included as a negative control material. In both laboratories, the respiratory allergens, but not the contact allergen, induced high titre antigen-specific antibodies in treated animals. The inhalation challenge results were similar in both laboratories but were less conclusive in that exposure to free TDI failed to induce pulmonary responses, probably because it fails to penetrate to the deep lung in sufficient concentration. Although the assay shows promise as a means of identifying chemical respiratory sensitisers, its use as a routine screen for the prediction of the ability of materials to induce respiratory allergy in man is probably questionable. PMID:7863510

Blaikie, L; Morrow, T; Wilson, A P; Hext, P; Hartop, P J; Rattray, N J; Woodcock, D; Botham, P A

1995-01-19

354

Ambient temperature and respiratory virus infection.  

PubMed

Respiratory viruses are important pediatric pathogens with pronounced seasonal patterns of circulation. Various hypotheses have been put forth to explain the seasonality of these infections, many involving environmental factors. This review summarizes the effect of temperature on the epidemicity of respiratory viruses, with an emphasis on epidemiological findings from large-scale metanalyses, laboratory-derived data using animal models and possible mechanisms to account for viral seasonality. PMID:24378933

Pica, Natalie; Bouvier, Nicole M

2014-03-01

355

Etiology of acute lower respiratory tract infection  

Microsoft Academic Search

Objective : To identify pathogens responsible for acute severe lower respiratory tract infection (ALRTI) in under five children by\\u000a non-invasive methods.Method : 95 children hospitalized with acute severe lower respiratory tract infection were investigated for identification of viruses,\\u000a bacteria, chlamydia or mycoplasma by nasopharyngeal aspirates, blood culture and serology.Result : Etiological agents could be identified in 94% of the patients.

S. K. Kabra; Rakesh Lodha; S. Broor; R. Chaudhary; M. Ghosh; R. S. Maitreyi

2003-01-01

356

An endophytic/pathogenic Phoma sp. from creosote bush producing biologically active volatile compounds having fuel potential.  

PubMed

A Phoma sp. was isolated and characterized as endophytic and as a pathogen of Larrea tridentata (creosote bush) growing in the desert region of southern Utah, USA. This fungus produces a unique mixture of volatile organic compounds (VOCs), including a series of sesquiterpenoids, some alcohols and several reduced naphthalene derivatives. Trans-caryophyllene, a product in the fungal VOCs, was also noted in the VOCs of this pungent plant. The gases of Phoma sp. possess antifungal properties and is markedly similar to that of a methanolic extract of the host plant. Some of the test organisms with the greatest sensitivity to the Phoma sp. VOCs were Verticillium, Ceratocystis, Cercospora and Sclerotinia while those being the least sensitive were Trichoderma, Colletotrichum and Aspergillus. We discuss the possible involvement of VOC production by the fungus and its role in the biology/ecology of the fungus/plant/environmental relationship with implications for utilization as an energy source. PMID:21535100

Strobel, Gary; Singh, Sanjay K; Riyaz-Ul-Hassan, Syed; Mitchell, Angela M; Geary, Brad; Sears, Joe

2011-07-01

357

Carriage by the housefly (Musca domestica) of multiple-antibiotic-resistant bacteria that are potentially pathogenic to humans, in hospital and other urban environments in Misurata, Libya.  

PubMed

Using standard microbiological procedures, bacteria that are potentially pathogenic to humans were isolated from 150 houseflies collected in the Libyan city of Misurata (50 flies each from the Central Hospital, streets and abattoir). Salmonella spp., Yersinia enterocolitica and Edwardsiella tarda were isolated from flies collected on the streets and in the abattoir but not from those collected in the hospital. Shigella sonnei was detected in just one fly, which was collected in the abattoir. Of the flies collected in the hospital, streets and abattor, 42%, 42% and 32% were positive for Escherichia coli, 70%, 50% and 62% for Klebsiella spp., 2%, 20% and 10% for Aeromonas spp., 96%, 36% and 34% for Pseudomonas spp., 20%, 12% and 16% for Staphylococcus spp., and 24%, 22% and 18% for Streptococcus spp., respectively. When the antibiotic susceptibilities of the fly isolates were investigated, the Enterobacteria isolated from the houseflies collected in the hospital were found to be resistant to significantly more of the commonly used antibiotics that were tested than the Enterobacteria isolated from the flies caught in the streets or abattoir. Whatever the source of the flies from which they were collected, the Pseudomonas isolates frequently showed resistance to multiple antibiotics, with >50% each being resistant to at least 10 antimicrobial agents. Two isolates of Sta. aureus (both from flies collected in the hospital) were resistant to methicillin. The present study supports the belief that the housefly is a potential vector of multiple-antibiotic-resistant, pathogenic bacteria, including methicillin-resistant Sta. aureus, in the hospital environment. Given their mobility, it seems likely that houseflies carry such pathogens from hospitals to surrounding communities, and vice versa. PMID:16297293

Rahuma, N; Ghenghesh, K S; Ben Aissa, R; Elamaari, A

2005-12-01

358

Testing for aerobic heterotrophic bacteria allows no prediction of contamination with potentially pathogenic bacteria in the output water of dental chair units  

PubMed Central

Background: Currently, to our knowledge, quality of output water of dental chair units is not covered by specific regulations in the European Union, and national recommendations are heterogeneous. In Germany, water used in dental chair units must follow drinking water quality. In the United States of America, testing for aerobic heterotrophic bacteria is recommended. The present study was performed to evaluate whether the counts of aerobic heterotrophic bacteria correlate with the presence of potentially pathogenic bacteria such as Legionella spp. or Pseudomonas aeruginosa. Methods: 71 samples were collected from 26 dental chair units with integrated disinfection device and 31 samples from 15 outlets of the water distribution pipework within the department were examined. Samples were tested for aerobic heterotrophic bacteria at 35°C and 22°C using different culture media and for Legionella spp. and for Pseudomonas aeruginosa. Additionally, strains of Legionella pneumophila serogroup 1 were typed with monoclonal antibodies and representative samples of Legionella pneumophila serogroup 1 were typed by sequence based typing. Results: Our results showed a correlation between different agars for aerobic heterotrophic bacteria but no correlation for the count of aerobic heterotrophic bacteria and the presence of Legionella spp. or Pseudomonas aeruginosa. Conclusion: Testing for aerobic heterotrophic bacteria in output water or water distribution pipework within the departments alone is without any value for predicting whether the water is contaminated with potentially pathogenic bacteria like Legionella spp. or Pseudomonas aeruginosa.

Bristela, Margit; Skolka, Astrid; Schmid-Schwap, Martina; Piehslinger, Eva; Indra, Alexander; Wewalka, Gunther; Stauffer, Fritz

2012-01-01

359

New strategies against Stenotrophomonas maltophilia: a serious worldwide intrinsically drug-resistant opportunistic pathogen.  

PubMed

Stenotrophomonas maltophilia is a worldwide human opportunistic pathogen associated with serious infections in humans, and is most often recovered from respiratory tract infections. In addition to its intrinsic drug resistance, this organism may acquire resistance via multiple molecular mechanisms. New antimicrobial strategies are needed to combat S. maltophilia infections, particularly in immunocompromised patients, cystic fibrosis patients with polymicrobial infections of the lung, and in patients with chronic infections. This editorial reports on newer drugs and antimicrobial strategies and their potential for use in treatment of S. maltophilia infections, the development of new technologies to detect this organism, and identifies strategies currently in use to reduce transmission of this pathogen. PMID:24308713

Brooke, Joanna S

2014-01-01

360

Induced changes in total serum IgE concentration in the Brown Norway rat: potential for identification of chemical respiratory allergens.  

PubMed

A variety of chemicals can cause sensitization of the respiratory tract and occupational asthma that may be associated with IgE antibody production. Topical exposure to chemical respiratory allergens such as trimellitic anhydride (TMA) has been shown previously to induce increases in the total serum concentration of IgE in BALB/c strain mice. Contact allergens such as 2,4-dinitrochlorobenzene (DNCB), which apparently lack respiratory sensitizing potential, fail to provoke similar changes. However, it became apparent with time that there was some inter-animal variation in constitutive and inducible IgE levels. We have now examined the influence of topical exposure to TMA and DNCB on serum IgE levels in the Brown Norway (BN) rat. Such animals can be bled serially and thus it is possible to perform longitudinal analyses of changes in serum IgE concentration. The kinetics of IgE responses therefore can be followed on an individual animal basis, allowing discrimination between transient and sustained increases in serum IgE concentration. Rats (n = 5) were exposed on shaved flanks to 50% TMA, to 1% DNCB (concentrations that elicit comparable immune activation with respect to draining lymph node cellularity and proliferation) or to vehicle alone. Total IgE was measured by enzyme-linked immunosorbent assay in serum samples taken prior to and 14-42 days following initial exposure. Those animals having high pre-existing IgE levels (>1.0 microg ml(-1)) were excluded from subsequent analyses. The levels of serum IgE in the majority of rats exposed to DNCB or vehicle alone remained relatively stable throughout the duration of all the experiments conducted, although some animals displayed transient increases in serum IgE. Only TMA treatment was associated with a significant and sustained increase in the level of serum IgE in the majority of experiments. The elevated concentrations of IgE induced by topical exposure to TMA are persistent, the results reported here demonstrating that induced changes in IgE are maximal or near maximal at approximately 35 days, with a significant increase in IgE demonstrable for at least 42 days following the initiation of exposure. Interestingly, although TMA and DNCB at the test concentrations used were found to be of comparable overall immunogenicity with regard to lymph node activation and the induction of lymph node cell proliferation, there were apparent differences in humoral immune responses. Thus, not only did exposure to TMA stimulate increases in total serum IgE concentration and the production of specific IgE antibody, but also a more vigorous IgG antibody response was provoked by TMA compared with DNCB. These data suggest that the measurement of induced changes in serum IgE concentration in the BN strain of rat is able to differentiate between different classes of chemical allergen. Given the inter-animal variation in IgE production, it would be prudent to incorporate a concurrent assessment of responses induced by treatment with TMA as a positive control against which to assess the activity of other test materials. PMID:11807923

Warbrick, E V; Dearman, R J; Kimber, I

2002-01-01

361

Moraxella catarrhalis: from emerging to established pathogen.  

PubMed

Moraxella catarrhalis (formerly known as Branhamella catarrhalis) has emerged as a significant bacterial pathogen of humans over the past two decades. During this period, microbiological and molecular diagnostic techniques have been developed and improved for M. catarrhalis, allowing the adequate determination and taxonomic positioning of this pathogen. Over the same period, studies have revealed its involvement in respiratory (e.g., sinusitis, otitis media, bronchitis, and pneumonia) and ocular infections in children and in laryngitis, bronchitis, and pneumonia in adults. The development of (molecular) epidemiological tools has enabled the national and international distribution of M. catarrhalis strains to be established, and has allowed the monitoring of nosocomial infections and the dynamics of carriage. Indeed, such monitoring has revealed an increasing number of B-lactamase-positive M. catarrhalis isolates (now well above 90%), underscoring the pathogenic potential of this organism. Although a number of putative M. catarrhalis virulence factors have been identified and described in detail, their relationship to actual bacterial adhesion, invasion, complement resistance, etc. (and ultimately their role in infection and immunity), has been established in a only few cases. In the past 10 years, various animal models for the study of M. catarrhalis pathogenicity have been described, although not all of these models are equally suitable for the study of human infection. Techniques involving the molecular manipulation of M. catarrhalis genes and antigens are also advancing our knowledge of the host response to and pathogenesis of this bacterial species in humans, as well as providing insights into possible vaccine candidates. This review aims to outline our current knowledge of M. catarrhalis, an organism that has evolved from an emerging to a well-established human pathogen. PMID:11781271

Verduin, Cees M; Hol, Cees; Fleer, André; van Dijk, Hans; van Belkum, Alex

2002-01-01

362

Quantitation of respiratory viruses in relation to clinical course in children with acute respiratory tract infections.  

PubMed

Quantitation of respiratory viruses by PCR could potentially aid in clinical interpretation of PCR results. We conducted a study in children admitted with acute respiratory tract infections to study correlations between the clinical course of illness and semiquantitative detection of 14 respiratory viruses. Clinical improvement was associated with reduction of viral quantity after 3 days of hospitalization. PMID:19858770

Jansen, Rogier R; Schinkel, Janke; Dek, Irene; Koekkoek, Sylvie M; Visser, Caroline E; de Jong, Menno D; Molenkamp, Richard; Pajkrt, Dasja

2010-01-01

363

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...

364

Potentially pathogenic nontuberculous mycobacteria found in aquatic systems. Analysis from a reclaimed water and water distribution system in Mexico City.  

PubMed

We investigated the presence of nontuberculous mycobacteria (NTM) in three Mexican aquatic systems to evaluate the prevalence with the distribution of NTM species. Key physicochemical parameters of the water samples were determined to find correlations with the species' distributions. We used multilocus sequence analysis (MLSA) based on hsp65, rpoB, and 16S rRNA fragments to determine their taxonomic affiliations. NTM were recovered from water distribution systems and reclaimed water from the Mexico City Metropolitan Area (MCMA). The isolated species were associated with a temperature of 21°C and pH >7.7. The phylogenetic analysis showed that eight of the 14 different NTM strains were unambiguously classifiable: Mycobacterium peregrinum, M. nonchromogenicum (2), M. smegmatis (2), M. fortuitum, M. avium ssp. hominissuis, M. arupense, M. gordonae, and M. chitae. One strain was tentatively identified as M. mantenni/ scrofulaceum and another strain was related to M. porcinum/M. septicum. All NTM species identified in the water distribution system were also detected in the reclaimed water, but some species from the reclaimed water were not found in the water distribution systems. Two of the identified species found in the reclaimed water, M. avium and M. fortuitum, are considered important human opportunistic pathogens. PMID:21805195

Castillo-Rodal, A I; Mazari-Hiriart, M; Lloret-Sánchez, L T; Sachman-Ruiz, B; Vinuesa, P; López-Vidal, Y

2012-05-01

365

Use of Zebrafish to Probe the Divergent Virulence Potentials and Toxin Requirements of Extraintestinal Pathogenic Escherichia coli  

PubMed Central

Extraintestinal pathogenic E. coli (ExPEC) cause an array of diseases, including sepsis, neonatal meningitis, and urinary tract infections. Many putative virulence factors that might modulate ExPEC pathogenesis have been identified through sequencing efforts, epidemiology, and gene expression profiling, but few of these genes have been assigned clearly defined functional roles during infection. Using zebrafish embryos as surrogate hosts, we have developed a model system with the ability to resolve diverse virulence phenotypes and niche-specific restrictions among closely related ExPEC isolates during either localized or systemic infections. In side-by-side comparisons of prototypic ExPEC isolates, we observed an unexpectedly high degree of phenotypic diversity that is not readily apparent using more traditional animal hosts. In particular, the capacity of different ExPEC isolates to persist and multiply within the zebrafish host and cause disease was shown to be variably dependent upon two secreted toxins, ?-hemolysin and cytotoxic necrotizing factor. Both of these toxins appear to function primarily in the neutralization of phagocytes, which are recruited in high numbers to sites of infection where they act as an essential host defense against ExPEC as well as less virulent E. coli strains. These results establish zebrafish as a valuable tool for the elucidation and functional analysis of both ExPEC virulence factors and host defense mechanisms.

Wiles, Travis J.; Bower, Jean M.; Redd, Michael J.; Mulvey, Matthew A.

2009-01-01

366

Oxidized fatty acids: A potential pathogenic link between fatty liver and type 2 diabetes in obese adolescents?  

PubMed

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/m(2)), 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. PMID:23815500

Santoro, Nicola; Caprio, Sonia; Giannini, Cosimo; Kim, Grace; Kursawe, Romy; Pierpont, Bridget; Shaw, Melissa M; Feldstein, Ariel E

2014-01-10

367

DDA adjuvant induces a mixed Th1\\/Th2 immune response when associated with BBG2Na, a respiratory syncytial virus potential vaccine  

Microsoft Academic Search

Human respiratory syncytial virus (hRSV) is one of the most common causes of respiratory infection in infants and the elderly. Previous attempts to vaccinate children against RSV failed and the induction of an aberrant Th2-type immune response was shown to induce severe to fatal pulmonary disease characterised in part by eosinophilia. BBG2Na is a promising human RSV subunit vaccine candidate

Christine Klinguer-Hamour; Christine Libon; Hélène Plotnicky-Gilquin; Marie-Claire Bussat; Lydie Revy; Thien Nguyen; Jean-Yves Bonnefoy; Alain Beck

2002-01-01

368

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

369

Attenuated and Replication-Competent Vaccinia Virus Strains M65 and M101 with Distinct Biology and Immunogenicity as Potential Vaccine Candidates against Pathogens  

PubMed Central

Replication-competent poxvirus vectors with an attenuation phenotype and with a high immunogenic capacity of the foreign expressed antigen are being pursued as novel vaccine vectors against different pathogens. In this investigation, we have examined the replication and immunogenic characteristics of two vaccinia virus (VACV) mutants, M65 and M101. These mutants were generated after 65 and 101 serial passages of persistently infected Friend erythroleukemia (FEL) cells. In cultured cells of different origins, the mutants are replication competent and have growth kinetics similar to or slightly reduced in comparison with those of the parental Western Reserve (WR) virus strain. In normal and immune-suppressed infected mice, the mutants showed different levels of attenuation and pathogenicity in comparison with WR and modified vaccinia Ankara (MVA) strains. Wide genome analysis after deep sequencing revealed selected genomic deletions and mutations in a number of viral open reading frames (ORFs). Mice immunized in a DNA prime/mutant boost regimen with viral vectors expressing the LACK (Leishmania homologue for receptors of activated C kinase) antigen of Leishmania infantum showed protection or a delay in the onset of cutaneous leishmaniasis. Protection was similar to that triggered by MVA-LACK. In immunized mice, both polyfunctional CD4+ and CD8+ T cells with an effector memory phenotype were activated by the two mutants, but the DNA-LACK/M65-LACK protocol preferentially induced CD4+ whereas DNA-LACK/M101-LACK preferentially induced CD8+ T cell responses. Altogether, our findings showed the adaptive changes of the WR genome during long-term virus-host cell interaction and how the replication competency of M65 and M101 mutants confers distinct biological properties and immunogenicity in mice compared to those of the MVA strain. These mutants could have applicability for understanding VACV biology and as potential vaccine vectors against pathogens and tumors.

Sanchez-Sampedro, Lucas; Gomez, Carmen Elena; Mejias-Perez, Ernesto; Perez-Jimenez, Eva; Oliveros, Juan Carlos

2013-01-01

370

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.

Anderson, Lucy G.; White, Piran C. L.; Stebbing, Paul D.; Stentiford, Grant D.; Dunn, Alison M.

2014-01-01

371

Transposon-based high sequence diversity in Avr-Pita alleles increases the potential for pathogenicity of Magnaporthe oryzae populations.  

PubMed

Magnaporthe oryzae causes rice blast that is one of the most devastating diseases of rice worldwide. Highly variable nature of this fungus has evolved itself against major resistance genes in newly released rice varieties. Understanding the population structure of this fungus is essential for proper utilization of the rice blast resistance genes in rice crop plants. In the present study, we analyzed 133 isolates of M. oryzae from ten countries to find the allelic variation of Avr-Pita gene that is triggering Pita-mediated resistance in rice plant. The diversity analysis of these alleles showed higher level of nucleotide variation in the coding regions than the noncoding regions. Evolutionary analysis of these alleles indicates that Avr-Pita gene is under purifying selection to favor its major alleles in 133 isolates analyzed in this study. We hypothesize that the selection of favorable Avr-Pita allele in these isolates may occur through a genetic mechanism known as recurrent selective sweeps. A total of 22 functional Avr-Pita protein variants were identified in this study. Insertion of Pot3 transposable element into the promoter of Avr-Pita gene was identified in virulent isolates and was suggested that mobility of repeat elements in avirulence genes of M. oryzae seems to help in emergence of new virulent types of the pathogen. Allele-specific markers developed in this study will be helpful to identify a particular type of Avr-Pita allele from M. oryzae population which can form the basis for the deployment of Pita gene in different epidemiological regions. PMID:24633351

Singh, P K; Thakur, S; Rathour, R; Variar, M; Prashanthi, S K; Singh, A K; Singh, U D; Sharma, V; Singh, N K; Sharma, T R

2014-06-01

372

[Recommendations for respiratory muscle testing].  

PubMed

Based on the tremendous impact of impaired respiratory muscle function, tests on their function play a significant role in respiratory and intensive care medicine. Besides differential diagnosing e.g. during prolonged weaning and quantification of impaired respiratory muscle function, e.g. in COPD, neuro-muscular diseases or ventilator-induced diaphragmatic dysfunction, those tests qualify for follow-up assessment, e.g. phrenic nerve lesions or specific respiratory muscle training. In general, (simple) volitional and (complex) non-volitional tests are available. Volitional tests aim at screening for potential respiratory muscle impairment, while non-volitional tests - including ultrasound application - are used to further specify low values assessed by volitional tests and to assess complex clinical conditions (e.g. intubated, sedated patients). Several tests are complementary or additive to each other. Complete assessment for respiratory muscle function, therefore, frequently requires the combination of different test regimes. The current recommendations include in-depth description and practical guidelines for the different tests and approaches to assess respiratory muscle function. PMID:24715428

Kabitz, H-J; Walterspacher, S; Mellies, U; Criée, C P; Windisch, W

2014-05-01

373

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.

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

2010-01-01

374

A cultured strain of "Helicobacter heilmannii," a human gastric pathogen, identified as H. bizzozeronii: evidence for zoonotic potential of Helicobacter.  

PubMed Central

We compared the characteristics of a cultured human "Helicobacter heilmannii" isolate with those of other helicobacters found in animals. Phenotypic, protein profile, 16S rDNA sequence, and DNA-DNA hybridization analyses identified the human strain as H. bizzozeronii, a species frequently found in dogs. Thus, H. bizzozeronii may have zoonotic potential.

Jalava, K.; On, S. L.; Harrington, C. S.; Andersen, L. P.; Hanninen, M. L.; Vandamme, P.

2001-01-01

375

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

PubMed

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

Wang, Yun F Wayne; Fu, Jianfeng

2014-05-01

376

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.

Fu, Jianfeng

2014-01-01

377

Report on ticks collected in the Southeast and Mid-West regions of Brazil: analyzing the potential transmission of tick-borne pathogens to man.  

PubMed

Specimens of ticks were collected in 1993, 1996, 1997, and 1998, mostly from wild and domestic animals in the Southeast and Mid-West regions of Brazil. Nine species of Amblyommidae were identified: Anocentor nitens, Amblyomma cajennense, Amblyomma ovale, Amblyomma fulvum, Amblyomma striatum, Amblyomma rotundatum, Boophilus microplus, Boophilus annulatus, and Rhipicephalus sanguineus. The potential of these tick species as transmitters of pathogens to man was analyzed. A Flaviviridade Flavivirus was isolated from Amblyomma cajennense specimens collected from a sick capybara (Hydrochaeris hydrochaeris). Amblyomma cajennense is the main transmitter of Rickettsia rickettsii (=R. rickettsi), the causative agent of spotted fever in Brazil. Wild mammals, mainly capybaras and deer, infested by ticks and living in close contact with cattle, horses and dogs, offer the risk of transmission of wild zoonosis to these domestic animals and to man. PMID:10881097

Figueiredo, L T; Badra, S J; Pereira, L E; Szabó, M P

1999-01-01

378

Successful topical respiratory tract immunization of primates against Ebola virus.  

PubMed

Ebola virus causes outbreaks of severe viral hemorrhagic fever with high mortality in humans. The virus is highly contagious and can be transmitted by contact and by the aerosol route. These features make Ebola virus a potential weapon for bioterrorism and biological warfare. Therefore, a vaccine that induces both systemic and local immune responses in the respiratory tract would be highly beneficial. We evaluated a common pediatric respiratory pathogen, human parainfluenza virus type 3 (HPIV3), as a vaccine vector against Ebola virus. HPIV3 recombinants expressing the Ebola virus (Zaire species) surface glycoprotein (GP) alone or in combination with the nucleocapsid protein NP or with the cytokine adjuvant granulocyte-macrophage colony-stimulating factor were administered by the respiratory route to rhesus monkeys--in which HPIV3 infection is mild and asymptomatic--and were evaluated for immunogenicity and protective efficacy against a highly lethal intraperitoneal challenge with Ebola virus. A single immunization with any construct expressing GP was moderately immunogenic against Ebola virus and protected 88% of the animals against severe hemorrhagic fever and death caused by Ebola virus. Two doses were highly immunogenic, and all of the animals survived challenge and were free of signs of disease and of detectable Ebola virus challenge virus. These data illustrate the feasibility of immunization via the respiratory tract against the hemorrhagic fever caused by Ebola virus. To our knowledge, this is the first study in which topical immunization through respiratory tract achieved prevention of a viral hemorrhagic fever infection in a primate model. PMID:17428868

Bukreyev, Alexander; Rollin, Pierre E; Tate, Mallory K; Yang, Lijuan; Zaki, Sherif R; Shieh, Wun-Ju; Murphy, Brian R; Collins, Peter L; Sanchez, Anthony

2007-06-01

379

Pathogen inactivation techniques.  

PubMed

The desire to rid the blood supply of pathogens of all types has led to the development of many technologies aimed at the same goal--eradication of the pathogen(s) without harming the blood cells or generating toxic chemical agents. This is a very ambitious goal, and one that has yet to be achieved. One approach is to shun the 'one size fits all' concept and to target pathogen-reduction agents at the Individual component types. This permits the development of technologies that might be compatible with, for example, plasma products but that would be cytocidal and thus incompatible with platelet concentrates or red blood cell units. The technologies to be discussed include solvent detergent and methylene blue treatments--designed to inactivate plasma components and derivatives; psoralens (S-59--amotosalen) designed to pathogen-reduce units of platelets; and two products aimed at red blood cells, S-303 (a Frale--frangible anchor-linker effector compound) and Inactine (a binary ethyleneimine). A final pathogen-reduction material that might actually allow one material to inactivate all three blood components--riboflavin (vitamin B2)--is also under development. The sites of action of the amotosalen (S-59), the S-303 Frale, Inactine, and riboflavin are all localized in the nucleic acid part of the pathogen. Solvent detergent materials act by dissolving the plasma envelope, thus compromising the integrity of the pathogen membrane and rendering it non-infectious. By disrupting the pathogen's ability to replicate or survive, its infectivity is removed. The degree to which bacteria and viruses are affected by a particular pathogen-reducing technology relates to its Gram-positive or Gram-negative status, to the sporulation characteristics for bacteria, and the presence of lipid or protein envelopes for viruses. Concerns related to photoproducts and other breakdown products of these technologies remain, and the toxicology of pathogen-reduction treatments is a major ongoing area of investigation. Clearly, regulatory agencies have a major role to play in the evaluation of these new technologies. This chapter will cover the several types of pathogen-reduction systems, mechanisms of action, the inactivation efficacy for specific types of pathogens, toxicology of the various systems and the published research and clinical trial data supporting their potential usefulness. Due to the nature of the field, pathogen reduction is a work in progress and this review should be considered as a snapshot in time rather than a clear picture of what the future will bring. PMID:16377551

Pelletier, J P R; Transue, S; Snyder, E L

2006-01-01