Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
evidence for phenotypic plasticity among multihost campylobacter jejuni and c. coli lineages, obtained using ribosomal multilocus sequence typing and raman spectroscopy.closely related bacterial isolates can display divergent phenotypes. this can limit the usefulness of phylogenetic studies for understanding bacterial ecology and evolution. here, we compare phenotyping based on raman spectrometric analysis of cellular composition to phylogenetic classification by ribosomal multilocus sequence typing (rmlst) in 108 isolates of the zoonotic pathogens campylobacter jejuni and c. coli. automatic relevance determination (ard) was used to identify informative peaks i ...201323204423
efficacy of oral fecal bacteriotherapy in rhesus macaques (macaca mulatta) with chronic diarrhea.chronic diarrhea remains the principal burden in providing health care for nonhuman primates in biomedical research facilities. although the exact etiology continues to puzzle nonhuman primate clinicians, recent research in humans has shown that restoring the indigenous microbial diversity may be successful in resolving cases of chronic diarrhea when other treatment modalities have failed. the process of restoring this microbial balance, known as fecal bacteriotherapy, uses the complete flora fr ...201323561941
campylobacter infection in poultry-processing workers, virginia, usa, 2008-2011.during a health hazard evaluation, we investigated 29 cases of laboratory-diagnosed campylobacter infection among workers at a poultry-processing plant. most infected employees worked at the plant <1 month, worked as live hangers, and lived at a state-operated center. to lessen the infection risk, we recommended improvements to engineering and administrative controls at the plant.201323347390
rapid detection of campylobacter antigen by enzyme immunoassay leads to increased positivity rates.campylobacter antigen detection by enzyme immunoassay (eia) provides rapid results compared to traditional culture. however, concern exists regarding specificity. verification studies of an eia compared to culture revealed a positive predictive value (ppv) of 91%, whereas ppv fell to 42% during routine diagnostic testing. we suggest all positive eia results be confirmed via culture.201323175262
symptomatic and asymptomatic campylobacter infections associated with reduced growth in peruvian children.although diarrheal illnesses are recognized as both a cause and effect of undernutrition, evidence for the effect of specific enteropathogens on early childhood growth remains limited. we estimated the effects of undernutrition as a risk factor for campylobacteriosis, as well as associations between symptomatic and asymptomatic campylobacter infections and growth.201323383356
marked host specificity and lack of phylogeographic population structure of campylobacter jejuni in wild birds.zoonotic pathogens often infect several animal species, and gene flow among populations infecting different host species may affect the biological traits of the pathogen including host specificity, transmissibility and virulence. the bacterium campylobacter jejuni is a widespread zoonotic multihost pathogen, which frequently causes gastroenteritis in humans. poultry products are important transmission vehicles to humans, but the bacterium is common in other domestic and wild animals, particularl ...201323356487
using major outer membrane protein typing as an epidemiological tool to investigate outbreaks caused by milk-borne campylobacter jejuni isolates in california.we describe using major outer membrane protein (momp) typing as a screen to compare the campylobacter jejuni pora gene sequences of clinical outbreak strains from human stool with the pora sequences of dairy farm strains isolated during two milk-borne campylobacteriosis outbreak investigations in california. the genetic relatedness of clinical and environmental strains with identical or closely related pora sequences was confirmed by multilocus sequence typing and pulsed-field gel electrophoresi ...201323115263
reply to "disk diffusion method for erythromycin and ciprofloxacin susceptibility testing of campylobacter jejuni and campylobacter coli". 201323269980
rapid methods for the detection of foodborne bacterial pathogens: principles, applications, advantages and limitations.the incidence of foodborne diseases has increased over the years and resulted in major public health problem globally. foodborne pathogens can be found in various foods and it is important to detect foodborne pathogens to provide safe food supply and to prevent foodborne diseases. the conventional methods used to detect foodborne pathogen are time consuming and laborious. hence, a variety of methods have been developed for rapid detection of foodborne pathogens as it is required in many food ana ...201425628612
rapid methods for the detection of foodborne bacterial pathogens: principles, applications, advantages and limitations.the incidence of foodborne diseases has increased over the years and resulted in major public health problem globally. foodborne pathogens can be found in various foods and it is important to detect foodborne pathogens to provide safe food supply and to prevent foodborne diseases. the conventional methods used to detect foodborne pathogen are time consuming and laborious. hence, a variety of methods have been developed for rapid detection of foodborne pathogens as it is required in many food ana ...201425628612
transcriptomic and proteomic analyses reveal key innate immune signatures in the host response to the gastrointestinal pathogen campylobacter concisus.pathogenic species within the genus campylobacter are responsible for a considerable burden on global health. campylobacter concisus is an emergent pathogen that plays a role in acute and chronic gastrointestinal disease. despite ongoing research on campylobacter virulence mechanisms, little is known regarding the immunological profile of the host response to campylobacter infection. in this study, we describe a comprehensive global profile of innate immune responses to c. concisus infection in ...201425486993
transcriptomic and proteomic analyses reveal key innate immune signatures in the host response to the gastrointestinal pathogen campylobacter concisus.pathogenic species within the genus campylobacter are responsible for a considerable burden on global health. campylobacter concisus is an emergent pathogen that plays a role in acute and chronic gastrointestinal disease. despite ongoing research on campylobacter virulence mechanisms, little is known regarding the immunological profile of the host response to campylobacter infection. in this study, we describe a comprehensive global profile of innate immune responses to c. concisus infection in ...201425486993
effect of administration route and dose escalation on plasma and intestinal concentrations of enrofloxacin and ciprofloxacin in broiler chickens.the (mis)use of fluoroquinolones in the fowl industry has led to an alarming incidence of fluoroquinolone resistance in pathogenic as well as commensal bacteria. next to simply reducing antimicrobial consumption, optimizing dosage regimens can be regarded as a suitable strategy to reduce antimicrobial resistance development without jeopardizing therapy efficacy and outcome. a first step in order to limit antimicrobial resistance is to assess the exposure of the intestinal microbiota to enrofloxa ...201425440469
multilocus sequence typing (mlst) and whole-genome mlst of campylobacter jejuni isolates from human infections in three districts during a seasonal peak in finland.a total of 95 human campylobacter jejuni isolates acquired from domestic infections and collected from three districts in finland during the seasonal peak (june to september) in 2012 were analyzed by pcr-based multilocus sequence typing (mlst) and by whole-genome sequencing (wgs). four predominant sequence types (sts) were detected among the isolates: st-45 (21%) and st-230 (14%, st-45 clonal complex [cc]), st-267 (21%, st-283 cc), and st-677 (19%, st-677 cc). in districts 1 and 3, most of the i ...201425232158
extraintestinal campylobacteriosis in rhesus macaques (macaca mulatta).two cases of clinical disease associated with extraintestinal campylobacter infection were recently encountered in rhesus macaques (macaca mulatta). the first case was that of a 3-y-old, male, rhesus macaque experimentally infected with siv, who presented with abdominal pain and a midabdominal mass and was euthanized. pathology findings included an abscess within the median liver lobe, fibrinopurulent peritonitis, and intestinal serositis with isolation of campylobacter fetus from the blood, liv ...201425527031
antimicrobial susceptibility profiles and molecular typing of campylobacter jejuni and campylobacter coli isolates from ducks in south korea.campylobacter is a food-borne zoonotic pathogen that causes human gastroenteritis worldwide. campylobacter bacteria are commensal in the intestines of many food production animals, including ducks and chickens. the objective of the study was to determine the prevalence of campylobacter species in domestic ducks, and the agar dilution method was used to determine resistance of the isolates to eight antibiotics. in addition, multilocus sequence typing (mlst) was performed to determine the sequence ...201425261524
systematic review and meta-analysis of the proportion of campylobacter cases that develop chronic sequelae.understanding of chronic sequelae development after campylobacter infection is limited. the objective of the study was to determine via systematic review and meta-analysis the proportion of campylobacter cases that develop chronic sequelae.201425416162
first case report of fatal sepsis due to campylobacter upsaliensis.we encountered a rare case of severe fatal infection in a 70-year-old woman due to campylobacter upsaliensis, identified by pcr amplification and sequencing analysis of the 16s rrna gene using dna extracted from the isolates. to our knowledge, fatal sepsis due to this organism has never been described to date.201425411172
first case report of fatal sepsis due to campylobacter upsaliensis.we encountered a rare case of severe fatal infection in a 70-year-old woman due to campylobacter upsaliensis, identified by pcr amplification and sequencing analysis of the 16s rrna gene using dna extracted from the isolates. to our knowledge, fatal sepsis due to this organism has never been described to date.201425411172
a phylogeny-based sampling strategy and power calculator informs genome-wide associations study design for microbial pathogens.whole genome sequencing is increasingly used to study phenotypic variation among infectious pathogens and to evaluate their relative transmissibility, virulence, and immunogenicity. to date, relatively little has been published on how and how many pathogen strains should be selected for studies associating phenotype and genotype. there are specific challenges when identifying genetic associations in bacteria which often comprise highly structured populations. here we consider general methodologi ...201425484920
intraspecies comparison of streptomyces pratensis genomes reveals high levels of recombination and gene conservation between strains of disparate geographic origin.streptomyces are widespread bacteria that contribute to the terrestrial carbon cycle and produce the majority of clinically useful antibiotics. while interspecific genomic diversity has been investigated among streptomyces, information is lacking on intraspecific genomic diversity. streptomyces pratensis has high rates of homologous recombination but the impact of such gene exchange on genome evolution and the evolution of natural product gene clusters remains uncharacterized.201425399205
comparative genomics of the campylobacter lari group.the campylobacter lari group is a phylogenetic clade within the epsilon subdivision of the proteobacteria and is part of the thermotolerant campylobacter spp., a division within the genus that includes the human pathogen campylobacter jejuni. the c. lari group is currently composed of five species (c. lari, campylobacter insulaenigrae, campylobacter volucris, campylobacter subantarcticus, and campylobacter peloridis), as well as a group of strains termed the urease-positive thermophilic campylob ...201425381664
in depth analysis of the helicobacter pylori cag pathogenicity island transcriptional responses.the severity of symptoms elicited by the widespread human pathogen helicobacter pylori is strongly influenced by the genetic diversity of the infecting strain. among the most important pathogen factors that carry an increased risk for gastric cancer are specific genotypes of the cag pathogenicity island (cag-pai), encoding a type iv secretion system (t4ss) responsible for the translocation of the caga effector oncoprotein. to date, little is known about the regulatory events important for the ex ...201424892739
the importance of the viable but non-culturable state in human bacterial pathogens.many bacterial species have been found to exist in a viable but non-culturable (vbnc) state since its discovery in 1982. vbnc cells are characterized by a loss of culturability on routine agar, which impairs their detection by conventional plate count techniques. this leads to an underestimation of total viable cells in environmental or clinical samples, and thus poses a risk to public health. in this review, we present recent findings on the vbnc state of human bacterial pathogens. the characte ...201424917854
phenotypic and genotypic diversity of thermophilic campylobacter spp. in commercial turkey flocks: a longitudinal study.poultry are recognized as a main reservoir of campylobacter spp. however, longitudinal studies investigating the persistence of campylobacter on commercial meat turkeys are rare. the objectives of this study were to determine the prevalence, antimicrobial susceptibility, and persistence of genotypically related strains of campylobacter spp. recovered from three commercial turkey farms in ohio belonging to a single producer. eight hundred ten samples were collected from birds aged 1 week to slaug ...201425184688
inhibition controls for qualitative real-time pcr assays: are they necessary for all specimen matrices?a retrospective analysis of 386,706 specimens representing a variety of matrix types used in qualitative real-time pcr assays determined the overall inhibition rate to be 0.87% when the inhibition control was added preextraction to 5,613 specimens and 0.01% when the inhibition control was added postextraction but preamplification in 381,093 specimens. inhibition rates of ≤ 1% were found for all specimen matrix types except urine and formalin-fixed, paraffin-embedded tissue.201424740078
human diarrhea infections associated with domestic animal husbandry: a systematic review and meta-analysis.domestic animal husbandry, a common practice globally, can lead to zoonotic transmission of enteric pathogens. however, this risk has received little attention to date. this systematic review and meta-analysis examines the evidence for an association between domestic exposure to food-producing animals and cases of human diarrhea and specific enteric infections. we performed a systematic review of available literature to examine domestic livestock and poultry as risk factors for diarrhea and appl ...201424812065
high-throughput sequencing of campylobacter jejuni insertion mutant libraries reveals mapa as a fitness factor for chicken colonization.campylobacter jejuni is a leading cause of gastrointestinal infections worldwide, due primarily to its ability to asymptomatically colonize the gastrointestinal tracts of agriculturally relevant animals, including chickens. infection often occurs following consumption of meat that was contaminated by c. jejuni during harvest. because of this, much interest lies in understanding the mechanisms that allow c. jejuni to colonize the chicken gastrointestinal tract. to address this, we generated a c. ...201424633877
detection, identification and quantification of campylobacter jejuni, coli and lari in food matrices all at once using multiplex qpcr.thermotolerant campylobacter jejuni, coli and lari are recognized as leading food-borne pathogens causing an acute bacterial enteritis worldwide. due to narrow spectrum of their biochemical activity, it is very complicated to distinguish between individual species. for reliable risk assessment, proper incidence evaluation or swift sample analysis regarding individual species, a demand for simple and rapid method for their distinguishing is reasonable. in this study, we evaluated a reliable and s ...201425057300
comparison of maldi-tof ms, gene sequencing and the vitek 2 for identification of seventy-three clinical isolates of enteropathogens.this study was performed to evaluate the analytical and practical performance of the matrix-assisted laser desorption ionization-time of flight mass spectrometry (maldi-tof ms) compared to the sequencing method and the vitek 2 system for identification of enteropathogens in the clinical microbiology laboratory.201424822116
campylobacter prosthetic joint infection.a 75-year-old man was diagnosed with probable campylobacter jejuni prosthetic knee infection after a diarrheal illness. joint aspirate and operative cultures were negative, but pcr of prosthesis sonicate fluid was positive, as was stool culture. nineteen additional cases of campylobacter prosthetic joint infection reported in the literature are reviewed.201424523462
cryptic ecology among host generalist campylobacter jejuni in domestic animals.homologous recombination between bacterial strains is theoretically capable of preventing the separation of daughter clusters, and producing cohesive clouds of genotypes in sequence space. however, numerous barriers to recombination are known. barriers may be essential such as adaptive incompatibility, or ecological, which is associated with the opportunities for recombination in the natural habitat. campylobacter jejuni is a gut colonizer of numerous animal species and a major human enteric pat ...201424689900
campylobacter colonization and proliferation in the broiler chicken upon natural field challenge is not affected by the bird growth rate or breed.the zoonotic association between campylobacter bacteria in poultry and humans has been characterized by decades of research which has attempted to elucidate the epidemiology of this complex relationship and to reduce carriage within poultry. while much work has focused on the mechanisms facilitating its success in contaminating chicken flocks (and other animal hosts), it remains difficult to consistently exclude campylobacter under field conditions. within the united kingdom poultry industry, va ...201425172857
exploring pfge for detecting large plasmids in campylobacter jejuni and campylobacter coli isolated from various retail meats.campylobacter spp. is one of the most prevalent bacterial pathogens in retail meat, particularly poultry, and is a leading cause of diarrhea in humans. studies related to campylobacter large plasmids are limited in the literature possibly due to difficulty in isolating them using available alkaline lysis methods. the objectives of this study were to determine the prevalence of plasmids, particularly large ones, in campylobacter spp. isolated from various oklahoma retail meats, and to explore pfg ...201425436507
repetitive sequence variations in the promoter region of the adhesin-encoding gene saba of helicobacter pylori affect transcription.the pathogenesis of diseases elicited by the gastric pathogen helicobacter pylori is partially determined by the effectiveness of adaptation to the variably acidic environment of the host stomach. adaptation includes appropriate adherence to the gastric epithelium via outer membrane protein adhesins such as saba. the expression of saba is subject to regulation via phase variation in the promoter and coding regions as well as repression by the two-component system arsrs. in this study, we investi ...201425022855
emerging technologies for the clinical microbiology laboratory.in this review we examine the literature related to emerging technologies that will help to reshape the clinical microbiology laboratory. these topics include nucleic acid amplification tests such as isothermal and point-of-care molecular diagnostics, multiplexed panels for syndromic diagnosis, digital pcr, next-generation sequencing, and automation of molecular tests. we also review matrix-assisted laser desorption ionization-time of flight (maldi-tof) and electrospray ionization (esi) mass spe ...201425278575
incidence of and factors associated with false positives in laboratory diagnosis of norovirus infection by amplification of the rna-dependent rna polymerase gene.conventional reverse transcription-polymerase chain reaction (rt-pcr) amplification of the rna-dependent rna polymerase (rdrp) gene remains a used method for the rapid detection of norovirus (nv) in clinical laboratories. the incidence of and factors associated with false positives in this assay have not been previously evaluated.201425264621
emerging rapid resistance testing methods for clinical microbiology laboratories and their potential impact on patient management.atypical and multidrug resistance, especially esbl and carbapenemase expressing enterobacteriaceae, is globally spreading. therefore, it becomes increasingly difficult to achieve therapeutic success by calculated antibiotic therapy. consequently, rapid antibiotic resistance testing is essential. various molecular and mass spectrometry-based approaches have been introduced in diagnostic microbiology to speed up the providing of reliable resistance data. pcr- and sequencing-based approaches are th ...201425343142
susceptibility to campylobacter infection is associated with the species composition of the human fecal microbiota.the gut microbiota is essential for human health, but very little is known about how the composition of this ecosystem can influence and respond to bacterial infections. here we address this by prospectively studying the gut microbiota composition before, during, and after natural campylobacter infection in exposed poultry abattoir workers. the gut microbiota composition was analyzed with 16s amplicon sequencing of fecal samples from poultry abattoir workers during the peak season of campylobact ...201425227462
comparison of the bd max enteric bacterial panel to routine culture methods for detection of campylobacter, enterohemorrhagic escherichia coli (o157), salmonella, and shigella isolates in preserved stool specimens.we compared the bd max enteric bacterial panel (ebp) to culture for the detection of salmonella, shigella, campylobacter, and shiga toxin-producing enterohemorrhagic escherichia coli (ehec) o157 in seeded stool samples. the ebp panel demonstrated superior sensitivity and reliably detected salmonella, ehec o157, shigella, and campylobacter at concentrations 1- to 2-log10 lower than those needed for culture detection.201424430460
evaluation of a loop-mediated isothermal amplification suite for the rapid, reliable, and robust detection of shiga toxin-producing escherichia coli in produce.shiga toxin-producing escherichia coli (stec) strains are a leading cause of produce-associated outbreaks in the united states. rapid, reliable, and robust detection methods are needed to better ensure produce safety. we recently developed a loop-mediated isothermal amplification (lamp) suite for stec detection. in this study, the stec lamp suite was comprehensively evaluated against real-time quantitative pcr (qpcr) using a large panel of bacterial strains (n = 156) and various produce items (s ...201424509927
accurate detection of campylobacter spp. antigens by immunochromatography and enzyme immunoassay in routine microbiological laboratory.campylobacter spp. are fastidious microorganisms, and their detection by culture depends on the freshness of the stool sample and the skills of the laboratory staff. to improve laboratory diagnosis, assays for the detection of specific antigens have been developed. here, we evaluated two assays for the detection of campylobacter spp.-specific antigens, i.e., one immunochromatographic test and one enzyme-linked immunosorbent assay (eia), in 38 frozen campylobacter spp.-positive specimens and pros ...201425215191
genomic evidence for the emergence and evolution of pathogenicity and niche preferences in the genus campylobacter.the genus campylobacter includes some of the most relevant pathogens for human and animal health; the continuous effort in their characterization has also revealed new species putatively involved in different kind of infections. nowadays, the available genomic data for the genus comprise a wide variety of species with different pathogenic potential and niche preferences. in this work, we contribute to enlarge this available information presenting the first genome for the species campylobacter sp ...201425193310
evolution and comparative genomics of campylobacter jejuni st-677 clonal complex.campylobacter is the most common bacterial cause of gastroenteritis in the european union with over 200,000 laboratory-confirmed cases reported annually. this is the first study to describe findings related to comparative genomics analyses of the sequence type (st)-677 clonal complex (cc), a campylobacter jejuni lineage associated with bacteremia cases in humans. we performed whole-genome sequencing, using illumina hiseq sequencing technology, on five related st-677 cc isolates from two chicken ...201425193305
identifying etiological agents causing diarrhea in low income ecuadorian communities.continued success in decreasing diarrheal disease burden requires targeted interventions. to develop such interventions, it is crucial to understand which pathogens cause diarrhea. using a case-control design we tested stool samples, collected in both rural and urban ecuador, for 15 pathogenic microorganisms. pathogens were present in 51% of case and 27% of control samples from the urban community, and 62% of case and 18% of control samples collected from the rural community. rotavirus and shige ...201425048373
same-day subtyping of campylobacter jejuni and c. coli isolates by use of multiplex ligation-dependent probe amplification-binary typing.campylobacteriosis is the most commonly reported form of human bacterial gastroenteritis in the world. sound identification of infectious sources requires subtyping, but the most widely used methods have turnaround times measured in days and require specialist equipment and skills. a multiplex ligation-dependent probe amplification-binary typing (mbit) assay was developed for subtyping campylobacter jejuni and campylobacter coli. it was tested on 245 isolates, including recent isolates from belg ...201424989612
emergence of multidrug-resistant campylobacter species isolates with a horizontally acquired rrna methylase.antibiotic-resistant campylobacter constitutes a serious threat to public health, and resistance to macrolides is of particular concern, as this class of antibiotics is the drug of choice for clinical therapy of campylobacteriosis. very recently, a horizontally transferrable macrolide resistance mediated by the rrna methylase gene erm(b) was reported in a campylobacter coli isolate, but little is known about the dissemination of erm(b) among campylobacter isolates and the association of erm(b)-c ...201424982085
occurrence of thermotolerant campylobacter in raw poultry meat, environmental and pigeon stools collected in open-air markets.campylobacteriosis was the most commonly reported zoonosis for confirmed human cases in european union during 2011. poultry meat was very often implicated in campylobacter infections in humans. in italy commerce of raw poultry meat is common in open-air markets: these areas can be considered at high risk of bacterial contamination due to the high presence birds like pigeons. the aim of this study was to collect data about the contamination by thermotolerant campylobacter of raw poultry meat comm ...201427800355
investigating the host specificity of campylobacter jejuni and campylobacter coli by sequencing gyrase subunit a.surveillance and field investigations of campylobacter infections require molecular tools with genetic markers appropriate for tracing purposes, i.e. based on the principle that some campylobacter lineages acquire a host signature under adaptive selection pressure. we developed a sequence-based method targeting the quinolone resistance determining region within the subunit a of dna gyrase (gyra). host specificity was evaluated by characterizing two collections of campylobacter jejuni (n = 430) a ...201425163418
a current overview of commercially available nucleic acid diagnostics approaches to detect and identify human gastroenteritis pathogens.gastroenteritis is caused by a wide range of viral, bacterial and parasitic pathogens and causes millions of deaths worldwide each year, particularly in infant populations in developing countries. traditional microbiological culture and immunological based tests are time consuming, laborious and often lack diagnostic specificity and sensitivity. as a result patients can receive suboptimal and/or inappropriate antimicrobial treatment. in recent years, rapid nucleic acid diagnostics (nad) technolo ...201427920992
genome analysis of bacillus amyloliquefaciens subsp. plantarum ucmb5113: a rhizobacterium that improves plant growth and stress management.the bacillus amyloliquefaciens subsp. plantarum strain ucmb5113 is a gram-positive rhizobacterium that can colonize plant roots and stimulate plant growth and defense based on unknown mechanisms. this reinforcement of plants may provide protection to various forms of biotic and abiotic stress. to determine the genetic traits involved in the mechanism of plant-bacteria association, the genome sequence of ucmb5113 was obtained by assembling paired-end illumina reads. the assembled chromosome of 3, ...201425119988
genes required for assembly of pili associated with the helicobacter pylori cag type iv secretion system.helicobacter pylori causes numerous alterations in gastric epithelial cells through processes that are dependent on activity of the cag type iv secretion system (t4ss). filamentous structures termed "pili" have been visualized at the interface between h. pylori and gastric epithelial cells, and previous studies suggested that pilus formation is dependent on the presence of the cag pathogenicity island (pai). thus far, there has been relatively little effort to identify specific genes that are re ...201424891108
inactivation of selected bacterial pathogens in dairy cattle manure by mesophilic anaerobic digestion (balloon type digester).anaerobic digestion of animal manure in biogas digesters has shown promise as a technology in reducing the microbial load to safe and recommended levels. we sought to treat dairy manure obtained from the fort hare dairy farm by investigating the survival rates of bacterial pathogens, through a total viable plate count method, before, during and after mesophilic anaerobic digestion. different microbiological media were inoculated with different serial dilutions of manure samples that were withdra ...201425026086
campylobacter infection in a cohort of rural children in moramanga, madagascar.campylobacter infection is the most common cause of bacterial gastroenteritis in developing countries, including madagascar. reports of pathogenicity have not been consistent and repeated exposures over time seem to lead to the development of protective immunity in developing areas. we conducted this study to support evidence for these hypotheses by exploring the association between infection and age, the reoccurrence of infection and the pathogenicity of campylobacter.201424996559
comparison of fecalswab and eswab devices for storage and transportation of diarrheagenic bacteria.using a collection (n = 12) of atcc and known stock isolates, as well as 328 clinical stool specimens, we evaluated the eswab and the new fecalswab liquid-based microbiology (lbm) devices for storing and transporting diarrheagenic bacteria. the stock isolates were stored in these swab devices up to 48 h at refrigeration (4°c) or room (∼25°c) temperature and up to 3 months at -20°c or -70°c. with the clinical stool specimens, the performances of the eswab and fecalswab were compared to those of r ...201424740083
antimicrobial susceptibility of campylobacter jejuni and campylobacter coli isolates obtained in montreal, quebec, canada, from 2002 to 2013.from 2002 to 2013 in montreal, quebec, canada, 38 campylobacter coli isolates were more frequently erythromycin, tetracycline, and ciprofloxacin resistant than 440 campylobacter jejuni subsp. jejuni isolates (18.4% versus 1.8%; p = 0.00005), of which the 148 isolates acquired abroad were more frequently erythromycin, tetracycline, and ciprofloxacin resistant than the 292 isolates acquired locally (5.4% versus 0%; p = 0.0001).201424759726
benefits and risks of antimicrobial use in food-producing animals.benefits and risks of antimicrobial drugs, used in food-producing animals, continue to be complex and controversial issues. this review comprehensively presents the benefits of antimicrobials drugs regarding control of animal diseases, protection of public health, enhancement of animal production, improvement of environment, and effects of the drugs on biogas production and public health associated with antimicrobial resistance. the positive and negative impacts, due to ban issue of antimicrobia ...201424971079
videotaped behavior as a predictor of clinical outcome in rhesus macaques (macaca mulatta).understanding the behavior of laboratory nhp facilitates health assessment and clinical care. we sought to characterize the behavior of critically ill rhesus macaques (macaca mulatta) and determine whether specific behaviors or behavioral changes might facilitate the determination of prognosis and clinical endpoints. twenty-two critically-ill subjects were videorecorded after they were removed from the outdoor breeding colony for diagnostic work-up and treatment. subjects were categorized as sur ...201424956211
hygromycin b and apramycin antibiotic resistance cassettes for use in campylobacter jejuni.campylobacter jejuni genetic manipulation is restricted by the limited number of antibiotic resistance cassettes available for use in this diarrheal pathogen. in this study, two antibiotic resistance cassettes were developed, encoding for hygromycin b and apramycin resistance, for use in mutagenesis or for selection of gene expression and complementation constructs in c. jejuni. first, the marker genes were successfully modified to allow for insertional mutagenesis or deletion of a gene-of-inter ...201424751825
comparison of conventional pcr, multiplex pcr, and loop-mediated isothermal amplification assays for rapid detection of arcobacter species.this study aimed to develop a loop-mediated isothermal amplification (lamp) method for the rapid detection of arcobacter species. specific primers targeting the 23s ribosomal rna gene were used to detect arcobacter butzleri, arcobacter cryaerophilus, and arcobacter skirrowii. the specificity of the lamp primer set was assessed using dna samples from a panel of arcobacter and campylobacter species, and the sensitivity was determined using serial dilutions of arcobacter species cultures. lamp show ...201424478488
detection and molecular analysis of campylobacter ureolyticus in domestic animals.previous studies showed the presence of campylobacter ureolyticus in a large proportion of diarrhoeal samples from patients in ireland. this emerging gastrointestinal pathogen was the second most common campylobacter species detected in patients presenting with gastroenteritis, surpassed only by c. jejuni. however, the source of c. ureolyticus infections in humans remains unknown. the aim of this study was to investigate the presence of c. ureolyticus in a range of domestic animals. over a perio ...201424739468
colonisation of a phage susceptible campylobacter jejuni population in two phage positive broiler flocks.the pathogens campylobacter jejuni and campylobacter coli are commensals in the poultry intestine and campylobacteriosis is one of the most frequent foodborne diseases in developed and developing countries. phages were identified to be effective in reducing intestinal campylobacter load and this was evaluated, in the first field trials which were recently carried out. the aim of this study was to further investigate campylobacter population dynamics during phage application on a commercial broil ...201424733154
draft genome sequence of campylobacter ureolyticus strain cit007, the first whole-genome sequence of a clinical isolate.herein, we present the draft genome sequence of campylobacter ureolyticus. strain cit007 was isolated from a stool sample from an elderly female presenting with diarrheal illness and end-stage chronic renal disease.201424723712
prevalence, antibiogram and risk factors of thermophilic campylobacter spp. in dressed porcine carcass of chitwan, nepal.campylobacter is the primary cause of food borne gastroenteritis. moreover, the emergence of multiple drug resistant campylobacters from poultry and pork has produced a potential threat to public health. research addressing these issues is sparse in nepal. so, this cross-sectional study aims at determining the prevalence, antibiogram and risk factors of campylobacters from dressed porcine carcass of chitwan, nepal.201424708489
identification of a novel membrane transporter mediating resistance to organic arsenic in campylobacter jejuni.although bacterial mechanisms involved in the resistance to inorganic arsenic are well understood, the molecular basis for organic arsenic resistance has not been described. campylobacter jejuni, a major food-borne pathogen causing gastroenteritis in humans, is highly prevalent in poultry and is reportedly resistant to the arsenic compound roxarsone (4-hydroxy-3-nitrobenzenearsonic acid), which has been used as a feed additive in the poultry industry for growth promotion. in this study, we repor ...201424419344
detection of campylobacter in stool and determination of significance by culture, enzyme immunoassay, and pcr in developing countries.campylobacter is a common bacterial enteropathogen that can be detected in stool by culture, enzyme immunoassay (eia), or pcr. we compared culture for c. jejuni/c. coli, eia (prospect), and duplex pcr to distinguish campylobacter jejuni/c. coli and non-jejuni/coli campylobacter on 432 diarrheal and matched control stool samples from infants in a multisite longitudinal study of enteric infections in tanzania, bangladesh, and peru. the sensitivity and specificity of culture were 8.5% and 97.6%, re ...201424452175
distribution of indigenous bacterial pathogens and potential pathogens associated with roof-harvested rainwater.the harvesting of rainwater is gaining acceptance among many governmental authorities in countries such as australia, germany, and south africa, among others. however, conflicting reports on the microbial quality of harvested rainwater have been published. to monitor the presence of potential pathogenic bacteria during high-rainfall periods, rainwater from 29 rainwater tanks was sampled on four occasions (during june and august 2012) in a sustainable housing project in kleinmond, south africa. t ...201424487540
comparative analysis and limitations of ethidium monoazide and propidium monoazide treatments for the differentiation of viable and nonviable campylobacter cells.the lack of differentiation between viable and nonviable bacterial cells limits the implementation of pcr-based methods for routine diagnostic approaches. recently, the combination of a quantitative real-time pcr (qpcr) and ethidium monoazide (ema) or propidium monoazide (pma) pretreatment has been described to circumvent this disadvantage. in regard to the suitability of this approach for campylobacter spp., conflicting results have been reported. thus, we compared the suitabilities of ema and ...201424487529
molecular testing for clinical diagnosis and epidemiological investigations of intestinal parasitic infections.over the past few decades, nucleic acid-based methods have been developed for the diagnosis of intestinal parasitic infections. advantages of nucleic acid-based methods are numerous; typically, these include increased sensitivity and specificity and simpler standardization of diagnostic procedures. dna samples can also be stored and used for genetic characterization and molecular typing, providing a valuable tool for surveys and surveillance studies. a variety of technologies have been applied, ...201424696439
[bacterial biofilms: their importance in animal health and public health].bacterial biofilms are structured communities of bacterial cells enclosed in a self-produced polymer matrix that is attached to a surface. biofilms protect and allow bacteria to survive and thrive in hostile environments. bacteria within biofilms can withstand host immune responses, and are much less susceptible to antibiotics and disinfectants when compared to their planktonic counterparts. the ability to form biofilms is now considered an attribute of many microorganisms. diseases associated w ...201424688172
metabolomic profiling and antioxidant activity of some acacia species.metabolomic profiling of different parts (leaves, flowers and pods) of acacia species (acacia nilotica, acacia seyal and acacia laeta) was evaluated. the multivariate data analyses such as principal component analysis (pca) and partial least square-discriminant analysis (pls-da) were used to differentiate the distribution of plant metabolites among different species or different organs of the same species. a. nilotica was characterized with a high content of saponins and a. seyal was characteriz ...201425313274
perspectives in the use of tannins as alternative to antimicrobial growth promoter factors in poultry.antibiotics have been included in the formulation of feed for livestock production for more than 40 years as a strategy to improve feed conversion rates and to reduce costs. the use of antimicrobials as growth-promoting factors (agp) in sub-therapeutic doses for long periods is particularly favorable for the selection of antimicrobial resistant microorganisms. in the last years, global concern about development of antimicrobial resistance and transference of resistance genes from animal to human ...201424723916
a reference pan-genome approach to comparative bacterial genomics: identification of novel epidemiological markers in pathogenic campylobacter.the increasing availability of hundreds of whole bacterial genomes provides opportunities for enhanced understanding of the genes and alleles responsible for clinically important phenotypes and how they evolved. however, it is a significant challenge to develop easy-to-use and scalable methods for characterizing these large and complex data and relating it to disease epidemiology. existing approaches typically focus on either homologous sequence variation in genes that are shared by all isolates ...201424676150
alternative bacteriophage life cycles: the carrier state of campylobacter jejuni.members of the genus campylobacter are frequently responsible for human enteric disease, often through consumption of contaminated poultry products. bacteriophages are viruses that have the potential to control pathogenic bacteria, but understanding their complex life cycles is key to their successful exploitation. treatment of campylobacter jejuni biofilms with bacteriophages led to the discovery that phages had established a relationship with their hosts typical of the carrier state life cycle ...201424671947
isolation of a campylobacter lanienae-like bacterium from laboratory chinchillas (chinchilla laniger).routine necropsies of 27 asymptomatic juvenile chinchillas revealed a high prevalence of gastric ulcers with microscopic lymphoplasmacytic gastroenteritis and typhlocolitis. polymerase chain reaction (pcr) analysis using campylobacter genus-specific partial 16s rrna primers revealed the presence of campylobacter spp. dna in the faeces of 12 of 27 animals (44.4%). species-specific partial 16s rrna pcr and sequencing confirmed that these animals were colonized with campylobacter lanienae, a gram-n ...201424628887
draft genome sequence of campylobacter coli strain ipsid-1 isolated from a patient with immunoproliferative small intestinal disease.the genome sequence and annotation of campylobacter coli strain ipsid-1 are reported here. this bacterial isolate is the first to be cultured from a patient with immunoproliferative small intestinal disease (ipsid). the draft genome sequence is 1.683 mb long, comprises 64 contigs, and has 31.26% g+c content.201424625865
a multiplex pcr/ldr assay for simultaneous detection and identification of the niaid category b bacterial food and water-borne pathogens.enteric pathogens that cause gastroenteritis remain a major global health concern. the goal of this study was to develop a multiplex pcr/ligation detection reaction (ldr) assay for the detection of all niaid category b bacterial food and water-borne pathogens directly from stool specimens. to validate the pcr/ldr assay, clinical isolates of campylobacter spp., vibrio spp., shigella spp., salmonella spp., listeria monocytogenes, yersinia enterocolitica, and diarrheagenic escherichia coli were tes ...201424709368
prevalence of virulence genes in strains of campylobacter jejuni isolated from human, bovine and broiler.campylobacter jejuni isolates of different origins (bovine, broiler meat, human) were screened by polymerase chain reaction for the presence of 4 genes cdtb, cst-ii, ggt, and virb11, previously linked to virulence such as adherence, invasion, colonization, molecular mimicry, and cytotoxin production. in addition, the isolates were screened for the presence of the global gene regulator csra linked to oxidative stress responses, biofilms formation, and cell adhesion. all the c. jejuni isolates wer ...201424688515
prevalence and pathogenic potential of campylobacter isolates from free-living, human-commensal american crows.recent studies have suggested a potential role for wild birds in zoonotic transmission of campylobacter jejuni, the leading cause of gastroenteritis in humans worldwide. in this study, we detected campylobacter spp. in 66.9% (85/127) of free-ranging american crows (corvus brachyrhyncos) sampled in the sacramento valley of california in 2012 and 2013. biochemical testing and sequence analysis of 16s rrna revealed that 93% of isolates (n = 70) were c. jejuni, with cytolethal distending toxin (cdt) ...201424375131
divergent distribution of the sensor kinase coss in non-thermotolerant campylobacter species and its functional incompatibility with the response regulator cosr of campylobacter jejuni.two-component signal transduction systems are commonly composed of a sensor histidine kinase and a cognate response regulator, modulating gene expression in response to environmental changes through a phosphorylation-dependent process. cosr is an ompr-type response regulator essential for the viability of campylobacter jejuni, a major foodborne pathogenic species causing human gastroenteritis. although cosr is a response regulator, its cognate sensor kinase has not been identified in c. jejuni. ...201424587027
antimicrobial resistance of bacterial enteropathogens isolated from stools in madagascar.diarrheal diseases are a major public health problem in developing countries, and are one of the main causes of hospital admissions in madagascar. the pasteur institute of madagascar undertook a study to determine the prevalence and the pathogenicity of bacterial, viral and protozoal enteropathogens in diarrheal and non-diarrheal stools of children aged less than 5 years in madagascar. we present here the results of the analysis of antimicrobial susceptibility of the bacteria isolated during thi ...201424568189
comparative genomics of unintrogressed campylobacter coli clades 2 and 3.campylobacter jejuni and c. coli share a multitude of risk factors associated with human gastrointestinal disease, yet their phylogeny differs significantly. c. jejuni is scattered into several lineages, with no apparent linkage, whereas c. coli clusters into three distinct phylogenetic groups (clades) of which clade 1 has shown extensive genome-wide introgression with c. jejuni, yet the other two clades (2 and 3) have less than 2% of c. jejuni ancestry. we characterized a c. coli strain (76339) ...201424524824
a severe case of persistent diarrhoea associated with arcobacter cryaerophilus but attributed to campylobacter sp. and a review of the clinical incidence of arcobacter spp.although rarely, arcobacter spp. have been associated with diarrhoea and bacteraemia. we report a persistent case in a healthy 26-year-old spanish male of bloody diarrhoea, which was attributed to campylobacter but in fact was caused by arcobacter cryaerophilus, as determined by sequencing of the rpob gene. the isolate was re-identified by matrix-assisted laser desorption ionization time of flight (maldi-tof) and genotyped for five putative virulence genes and for seven genes included in the arc ...201425356338
the sweet tooth of bacteria: common themes in bacterial glycoconjugates.humans have been increasingly recognized as being superorganisms, living in close contact with a microbiota on all their mucosal surfaces. however, most studies on the human microbiota have focused on gaining comprehensive insights into the composition of the microbiota under different health conditions (e.g., enterotypes), while there is also a need for detailed knowledge of the different molecules that mediate interactions with the host. glycoconjugates are an interesting class of molecules fo ...201425184559
a quantitative prioritisation of human and domestic animal pathogens in europe.disease or pathogen risk prioritisations aid understanding of infectious agent impact within surveillance or mitigation and biosecurity work, but take significant development. previous work has shown the h-(hirsch-)index as an alternative proxy. we present a weighted risk analysis describing infectious pathogen impact for human health (human pathogens) and well-being (domestic animal pathogens) using an objective, evidence-based, repeatable approach; the h-index. this study established the highe ...201425136810
the molecular evolution of the qo motif.quinol oxidation in the catalytic quinol oxidation site (q(o) site) of cytochrome (cyt) bc(1) complexes is the key step of the q cycle mechanism, which laid the ground for mitchell's chemiosmotic theory of energy conversion. bifurcated electron transfer upon quinol oxidation enables proton uptake and release on opposite membrane sides, thus generating a proton gradient that fuels atp synthesis in cellular respiration and photosynthesis. the q(o) site architecture formed by cyt b and rieske iron- ...201425115012
thermal control of virulence factors in bacteria: a hot topic.pathogenic bacteria sense environmental cues, including the local temperature, to control the production of key virulence factors. thermal regulation can be achieved at the level of dna, rna or protein and although many virulence factors are subject to thermal regulation, the exact mechanisms of control are yet to be elucidated in many instances. understanding how virulence factors are regulated by temperature presents a significant challenge, as gene expression and protein production are often ...201425494856
detection of zoonotic pathogens and characterization of novel viruses carried by commensal rattus norvegicus in new york city.norway rats (rattus norvegicus) are globally distributed and concentrate in urban environments, where they live and feed in closer proximity to human populations than most other mammals. despite the potential role of rats as reservoirs of zoonotic diseases, the microbial diversity present in urban rat populations remains unexplored. in this study, we used targeted molecular assays to detect known bacterial, viral, and protozoan human pathogens and unbiased high-throughput sequencing to identify ...201425316698
biological roles of the o-methyl phosphoramidate capsule modification in campylobacter jejuni.campylobacter jejuni is a major cause of bacterial gastroenteritis worldwide, and the capsular polysaccharide (cps) of this organism is required for persistence and disease. c. jejuni produces over 47 different capsular structures, including a unique o-methyl phosphoramidate (meopn) modification present on most c. jejuni isolates. although the meopn structure is rare in nature it has structural similarity to some synthetic pesticides. in this study, we have demonstrated, by whole genome comparis ...201424498018
presence and analysis of plasmids in human and animal associated arcobacter species.in this study, we report the screening of four arcobacter species for the presence of small and large plasmids. plasmids were present in 9.9% of the 273 examined strains. one arcobacter cryaerophilus and four arcobacter butzleri plasmids were selected for further sequencing. the size of three small plasmids isolated from a. butzleri and the one from a. cryaerophilus strains ranged between 4.8 and 5.1 kb, and the size of the large plasmid, isolated from a. butzleri, was 27.4 kbp. the g+c content ...201424465575
detection of cdt toxin genes in campylobacter spp. strains isolated from broiler carcasses and vegetables in são paulo, brazil.campylobacteriosis is a worldwide distributed zoonosis. one of the main virulence factors related to campylobacter spp. in animals and humans is the cytolethal distending toxin (cdt), encoded by three adjacent genes (cdta, cdtb, cdtc). the occurrence of campylobacter spp. in samples of vegetables has not been reported in brazil yet, and has seldom been described in the international literature. the detection of cdt in these strains has not been reported, either. the objectives of the present stu ...201424516435
isolation and antimicrobial susceptibility patterns of campylobacter species among diarrheic children at jimma, ethiopia.introduction. campylobacter is one of the leading bacterial causes of food-borne disease. the prevalence of campylobacter species resistant to antimicrobial agents is increasing. this study is intended to determine prevalence and antimicrobial susceptibility patterns of campylobacter species among under-five children with diarrhea. methodology. a cross-sectional study was conducted among 227 under-five children with diarrhea from july to october 2012 at jimma town. isolation and identification o ...201426904735
the renaissance of bacillosamine and its derivatives: pathway characterization and implications in pathogenicity.prokaryote-specific sugars, including n,n'-diacetylbacillosamine (dinacbac) and pseudaminic acid, have experienced a renaissance in the past decade because of their discovery in glycans related to microbial pathogenicity. dinacbac is found at the reducing end of oligosaccharides of n- and o-linked bacterial protein glycosylation pathways of gram-negative pathogens, including campylobacter jejuni and neisseria gonorrhoeae. further derivatization of dinacbac results in the nonulosonic acid known a ...201424383882
comparison of characteristics of patients infected by campylobacter jejuni, campylobacter coli, and campylobacter fetus.a large database of campylobacter isolates precisely identified at the species level was used to compare patients' characteristics. in a multivariate analysis, campylobacter coli was found more often in older patients and in patients having traveled abroad and less often in summertime than campylobacter jejuni. campylobacter fetus infection occurred in much older patients and in hospitalized patients with a systemic disease.201424197884
lipooligosaccharide locus class of campylobacter jejuni: sialylation is not needed for invasive infection.campylobacter jejuni is a highly diverse enteropathogen that is commonly detected worldwide. it can sometimes cause bacteraemia, but the bacterial characteristics facilitating bloodstream infection are not known. a total of 73 c. jejuni isolates, consecutively collected from blood-borne infections during a 10-year period all over finland and for which detailed clinical information of the patients were available, were included. we screened the isolates by pcr for the lipooligosaccharide (los) loc ...201424102802
target optimization for peptide nucleic acid (pna)-mediated antisense inhibition of the cmeabc multidrug efflux pump in campylobacter jejuni.cmeabc is a resistance-nodulation-cell division (rnd)-type multidrug efflux pump conferring resistance to clinically important antibiotics in campylobacter. this study aimed to identify the optimal target sites for the inhibition of cmeabc with antisense peptide nucleic acid (pna).201424084637
an epidemiological investigation of campylobacter in pig and poultry farms in the mekong delta of vietnam.campylobacter are zoonotic pathogens commonly associated with gastroenteritis. to assess the relevance of campylobacter in vietnam, an economically transitioning country in se asia, we conducted a survey of 343 pig and poultry farms in the mekong delta, a region characterized by mixed species farming with limited biosecurity. the animal-level prevalence of campylobacter was 31·9%, 23·9% and 53·7% for chickens, ducks and pigs, respectively. c. jejuni was predominant in all three host species, wit ...201424067502
identification and characterization of an invasion antigen b gene from the oral pathogen campylobacter rectus.the oral bacterium, campylobacter rectus, is an etiological agent of periodontitis. the virulence genes of c. rectus are largely unknown. the aim of this study was to query c. rectus for the presence of an invasion antigen b (ciab) gene, which is needed for cell invasion by the related species campylobacter jejuni. pcr and pcr-walking identified a ciab from c. rectus. in silico analyses of c. rectus 314 ciab (cr-ciab) revealed an orf of 1,830 base pairs. the cr-ciab protein shared significant se ...201424426164
prevalence and antimicrobial susceptibility of campylobacter spp. in oklahoma conventional and organic retail poultry.campylobacter is one of the most important foodborne pathogens that cause bacterial gastroenteritis.this study was conducted to investigate the prevalence and antimicrobial resistance of campylobacter in conventional and organic retail poultry samples purchased from grocery stores in tulsa, oklahoma.one hundred and fifty six chilled retail chicken samples (85 conventional and 71 organic) and 65 chilled retail conventional turkey samples were collected in this study. the prevalence of campylobact ...201425408778
differences in carbon source utilisation distinguish campylobacter jejuni from campylobacter coli.campylobacter jejuni and c. coli are human intestinal pathogens that are the most frequent causes of bacterial foodborne gastroenteritis in humans in the uk. in this study, we aimed to characterise the metabolic diversity of both c. jejuni and c. coli using a diverse panel of clinical strains isolated from the uk, pakistan and thailand, thereby representing both the developed and developing world. our aim was to apply multi genome analysis and biolog phenotyping to determine differences in carbo ...201425348335
Refresh
firstprev
...11121314151617181920...
nextlast
Displaying items 1901 - 2000 of 2341