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1.
Foodborne Pathog Dis ; 13(4): 212-20, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26859628

RESUMO

Enterotoxigenic Escherichia coli (ETEC) are an important cause of diarrhea in children under the age of 5 years in developing countries and are the leading bacterial agent of traveler's diarrhea in persons traveling to these countries. ETEC strains secrete heat-labile (LT) and/or heat-stable (ST) enterotoxins that induce diarrhea by causing water and electrolyte imbalance. We describe the validation of a real-time TaqMan PCR (RT-PCR) assay to detect LT, ST1a, and ST1b enterotoxin genes in E. coli strains and in stool specimens. We validated LT/ST1b duplex and ST1a single-plex RT-PCR assay using a conventional PCR assay as a gold standard with 188 ETEC strains and 42 non-ETEC strains. We validated LT/ST1b duplex and ST1a single-plex RT-PCR assay in stool specimens (n = 106) using traditional culture as the gold standard. RT- PCR assay sensitivities for LT, ST1a, and ST1b detection in strains were 100%, 100%, and 98%; specificities were 95%, 98%, and 99%, and Pearson correlation coefficient r was 0.9954 between RT-PCR assay and the gold standard. In stool specimens, RT-PCR assay sensitivities for LT, ST1a, and ST1b detection were 97%, 100%, and 97%; and specificities were 99%, 94%, and 97%. Pearson correlation coefficient r was 0.9975 between RT-PCR results in stool specimens and the gold standard. Limits of detection of LT, ST1a, and ST1b by RT-PCR assay were 0.1 to1.0 pg/µL and by conventional PCR assay were 100 to1000 pg/µL. The accuracy, rapidity and sensitivity of this RT-PCR assay is promising for ETEC detection in public health/clinical laboratories and for laboratories in need of an independent method to confirm results of other culture independent diagnostic tests.


Assuntos
Disenteria/microbiologia , Escherichia coli Enterotoxigênica/genética , Enterotoxinas/genética , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Centers for Disease Control and Prevention, U.S. , DNA Bacteriano/isolamento & purificação , DNA Bacteriano/metabolismo , Surtos de Doenças , Escherichia coli Enterotoxigênica/classificação , Escherichia coli Enterotoxigênica/isolamento & purificação , Escherichia coli Enterotoxigênica/metabolismo , Enterotoxinas/química , Enterotoxinas/metabolismo , Monitoramento Epidemiológico , Infecções por Escherichia coli/diagnóstico , Infecções por Escherichia coli/epidemiologia , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Fezes/microbiologia , Temperatura Alta , Humanos , Limite de Detecção , Tipagem Molecular , Reação em Cadeia da Polimerase Multiplex , Estabilidade Proteica , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Fatores de Tempo , Estados Unidos/epidemiologia
2.
PLoS Med ; 9(7): e1001256, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22802736

RESUMO

BACKGROUND: Diarrhea is a leading cause of childhood morbidity and mortality in sub-Saharan Africa. Data on risk factors for mortality are limited. We conducted hospital-based surveillance to characterize the etiology of diarrhea and identify risk factors for death among children hospitalized with diarrhea in rural western Kenya. METHODS AND FINDINGS: We enrolled all children <5 years old, hospitalized with diarrhea (≥3 loose stools in 24 hours) at two district hospitals in Nyanza Province, western Kenya. Clinical and demographic information was collected. Stool specimens were tested for bacterial and viral pathogens. Bivariate and multivariable logistic regression analyses were carried out to identify risk factors for death. From May 23, 2005 to May 22, 2007, 1,146 children <5 years old were enrolled; 107 (9%) children died during hospitalization. Nontyphoidal Salmonella were identified in 10% (118), Campylobacter in 5% (57), and Shigella in 4% (42) of 1,137 stool samples; rotavirus was detected in 19% (196) of 1,021 stool samples. Among stools from children who died, nontyphoidal Salmonella were detected in 22%, Shigella in 11%, rotavirus in 9%, Campylobacter in 5%, and S. Typhi in <1%. In multivariable analysis, infants who died were more likely to have nontyphoidal Salmonella (adjusted odds ratio [aOR] = 6·8; 95% CI 3·1-14·9), and children <5 years to have Shigella (aOR = 5·5; 95% CI 2·2-14·0) identified than children who survived. Children who died were less likely to be infected with rotavirus (OR = 0·4; 95% CI 0·2-0·8). Further risk factors for death included being malnourished (aOR = 4·2; 95% CI 2·1-8·7); having oral thrush on physical exam (aOR = 2·3; 95% CI 1·4-3·8); having previously sought care at a hospital for the illness (aOR = 2·2; 95% CI 1·2-3·8); and being dehydrated as diagnosed at discharge/death (aOR = 2·5; 95% CI 1·5-4·1). A clinical diagnosis of malaria, and malaria parasites seen on blood smear, were not associated with increased risk of death. This study only captured in-hospital childhood deaths, and likely missed a substantial number of additional deaths that occurred at home. CONCLUSION: Nontyphoidal Salmonella and Shigella are associated with mortality among rural Kenyan children with diarrhea who access a hospital. Improved prevention and treatment of diarrheal disease is necessary. Enhanced surveillance and simplified laboratory diagnostics in Africa may assist clinicians in appropriately treating potentially fatal diarrheal illness.


Assuntos
Mortalidade da Criança , Diarreia/epidemiologia , Hospitalização/estatística & dados numéricos , População Rural/estatística & dados numéricos , Distribuição por Idade , Pré-Escolar , Técnicas de Laboratório Clínico , Diarreia/diagnóstico , Diarreia/microbiologia , Feminino , Humanos , Lactente , Quênia/epidemiologia , Modelos Logísticos , Masculino , Análise Multivariada , Vigilância da População , Fatores de Risco
3.
J Clin Microbiol ; 50(7): 2343-52, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22535979

RESUMO

In this study, 77 clinical and 67 oyster Vibrio parahaemolyticus isolates from North America were examined for biochemical profiles, serotype, and the presence of potential virulence factors (tdh, trh, and type III secretion system [T3SS] genes). All isolates were positive for oxidase, indole, and glucose fermentation, consistent with previous reports. The isolates represented 35 different serotypes, 9 of which were shared by clinical and oyster isolates. Serotypes associated with pandemic strains (O1:KUT, O1:K25, O3:K6, and O4:K68) were observed for clinical isolates, and 7 (9%) oyster isolates belonged to serotype O1:KUT. Of the clinical isolates, 27% were negative for tdh and trh, while 45% contained both genes. Oyster isolates were preferentially selected for the presence of tdh and/or trh; 34% contained both genes, 42% had trh but not tdh, and 3% had tdh but not trh. All but 1 isolate (143/144) had at least three of the four T3SS1 genes examined. The isolates lacking both tdh and trh contained no T3SS2α or T3SS2ß genes. All clinical isolates positive for tdh and negative for trh possessed all T3SS2α genes, and all isolates negative for tdh and positive for trh possessed all T3SS2ß genes. The two oyster isolates containing tdh but not trh possessed all but the vopB2 gene of T3SS2α, as reported previously. In contrast to the findings of previous studies, all strains examined that were positive for both tdh and trh also carried T3SS2ß genes. This report identifies the serotype as the most distinguishing feature between clinical and oyster isolates. Our findings raise concerns about the reliability of the tdh, trh, and T3SS genes as virulence markers and highlight the need for more-detailed pathogenicity investigations of V. parahaemolyticus.


Assuntos
Ostreidae/microbiologia , Vibrioses/microbiologia , Vibrio parahaemolyticus/classificação , Vibrio parahaemolyticus/isolamento & purificação , Animais , Técnicas de Tipagem Bacteriana , Genes Bacterianos , Humanos , América do Norte , Sorotipagem , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/metabolismo , Fatores de Virulência/genética
4.
Emerg Infect Dis ; 17(11): 2147-50, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22099121

RESUMO

During the 2010 cholera outbreak in Haiti, water and seafood samples were collected to detect Vibrio cholerae. The outbreak strain of toxigenic V. cholerae O1 serotype Ogawa was isolated from freshwater and seafood samples. The cholera toxin gene was detected in harbor water samples.


Assuntos
Cólera/transmissão , Água Doce/microbiologia , Alimentos Marinhos/microbiologia , Vibrio cholerae O1/isolamento & purificação , Cólera/epidemiologia , Toxina da Cólera/genética , Surtos de Doenças , Haiti/epidemiologia , Humanos , Vibrio cholerae O1/genética
5.
Appl Environ Microbiol ; 75(21): 6745-56, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19749061

RESUMO

Vibrio parahaemolyticus is a pathogenic marine bacterium that is the main causative agent of bacterial seafood-borne gastroenteritis in the United States. An increase in the frequency of V. parahaemolyticus-related infections during the last decade has been attributed to the emergence of an O3:K6 pandemic clone in 1995. The diversity of the O3:K6 pandemic clone and its serovariants has been examined using multiple molecular techniques including multilocus sequence analysis, pulsed-field gel electrophoresis, and group-specific PCR analysis. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has become a powerful tool for rapidly distinguishing between related bacterial species. In the current study, we demonstrate the development of a whole-cell MALDI-TOF MS method for the distinction of V. parahaemolyticus from other Vibrio spp. We identified 30 peaks that were present only in the spectra of the V. parahaemolyticus strains examined in this study that may be developed as MALDI-TOF MS biomarkers for identification of V. parahaemolyticus. We detected variation in the MALDI-TOF spectra of V. parahaemolyticus strains isolated from different geographical locations and at different times. The MALDI-TOF MS spectra of the V. parahaemolyticus strains examined were distinct from those of the other Vibrio species examined including the closely related V. alginolyticus, V. harveyi, and V. campbellii. The results of this study demonstrate the first use of whole-cell MALDI-TOF MS analysis for the rapid identification of V. parahaemolyticus.


Assuntos
Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Vibrio parahaemolyticus/química , Vibrio parahaemolyticus/isolamento & purificação , Análise por Conglomerados , Impressões Digitais de DNA , DNA Bacteriano/química , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Genótipo , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Estados Unidos , Vibrioses/diagnóstico
6.
Clin Infect Dis ; 47(1): 1-7, 2008 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-18491967

RESUMO

BACKGROUND: In August and November 2004, 2 clusters of diarrhea cases occurred among patrons of 2 affiliated sushi restaurants (sushi restaurant A and sushi restaurant B) in Nevada. In August 2004, a stool sample from 1 ill sushi restaurant A patron yielded enterotoxigenic Escherichia coli (ETEC). In December 2004, we investigated a third cluster of diarrhea cases among sushi restaurant B patrons. METHODS: We defined a case as diarrhea in a person who ate at sushi restaurant B from 3 December through 13 December 2004. Control subjects were individuals who dined with case patients but did not become ill. Duplex polymerase chain reaction was used to detect genes coding for heat-stable and heat-labile enterotoxins of ETEC. RESULTS: One-hundred thirty patrons of sushi restaurant B reported illness; we enrolled 36 case patients and 29 control subjects. The diarrhea-to-vomiting prevalence ratio among patients was 4.5. Illness was associated with consumption of butterfly shrimp (estimated odds ratio, 7.2; 95% confidence interval, 1.1 to infinity). The implicated food was distributed to many restaurants, but only sushi restaurant B patrons reported diarrhea. We observed poor food-handling and hand hygiene practices at sushi restaurant B. Stool samples from 6 of 7 ill patrons and 2 of 27 employees who denied illness yielded ETEC. CONCLUSIONS: ETEC was identified as the etiologic agent of a large foodborne outbreak at a sushi restaurant in Nevada. Poor food-handling practices and infected foodhandlers likely contributed to this outbreak. Although ETEC is a well-documented cause of domestic foodborne outbreaks, few laboratories can test for it. Earlier recognition of ETEC infections may prevent subsequent outbreaks from occurring.


Assuntos
Diarreia/epidemiologia , Diarreia/microbiologia , Surtos de Doenças , Escherichia coli Enterotoxigênica/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Microbiologia de Alimentos , Adulto , Idoso , Toxinas Bacterianas/genética , Impressões Digitais de DNA , DNA Bacteriano/genética , Farmacorresistência Bacteriana , Eletroforese em Gel de Campo Pulsado , Escherichia coli Enterotoxigênica/classificação , Escherichia coli Enterotoxigênica/genética , Enterotoxinas/genética , Proteínas de Escherichia coli/genética , Fezes/microbiologia , Feminino , Manipulação de Alimentos/métodos , Humanos , Higiene , Masculino , Pessoa de Meia-Idade , Nevada/epidemiologia , Restaurantes
7.
N Engl J Med ; 353(14): 1463-70, 2005 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-16207848

RESUMO

BACKGROUND: Vibrio parahaemolyticus, the leading cause of seafood-associated gastroenteritis in the United States, typically is associated with the consumption of raw oysters gathered from warm-water estuaries. We describe a recognized outbreak of V. parahaemolyticus infection associated with the consumption of seafood from Alaska. METHODS: After we received reports of the occurrence of gastroenteritis on a cruise ship, we conducted a retrospective cohort study among passengers, as well as active surveillance throughout Alaska to identify additional cases, and an environmental study to identify sources of V. parahaemolyticus and contributors to the outbreak. RESULTS: Of 189 passengers, 132 (70 percent) were interviewed; 22 of the interviewees (17 percent) met our case definition of gastroenteritis. In our multiple logistic-regression analysis, consumption of raw oysters was the only significant predictor of illness; the attack rate among people who consumed oysters was 29 percent. Active surveillance identified a total of 62 patients with gastroenteritis. V. parahaemolyticus serotype O6:K18 was isolated from the majority of patients tested and from environmental samples of oysters. Patterns on pulsed-field gel electrophoresis were highly related across clinical and oyster isolates. All oysters associated with the outbreak were harvested when mean daily water temperatures exceeded 15.0 degrees C (the theorized threshold for the risk of V. parahaemolyticus illness from the consumption of raw oysters). Since 1997, mean water temperatures in July and August at the implicated oyster farm increased 0.21 degrees C per year (P<0.001 by linear regression); 2004 was the only year during which mean daily temperatures in July and August at the shellfish farm did not drop below 15.0 degrees C. CONCLUSIONS: This investigation extends by 1000 km the northernmost documented source of oysters that caused illness due to V. parahaemolyticus. Rising temperatures of ocean water seem to have contributed to one of the largest known outbreaks of V. parahaemolyticus in the United States.


Assuntos
Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Gastroenterite/microbiologia , Ostreidae/microbiologia , Intoxicação por Frutos do Mar , Vibrioses/epidemiologia , Vibrio parahaemolyticus/isolamento & purificação , Adolescente , Adulto , Idoso , Alaska/epidemiologia , Animais , Aquicultura , Criança , Estudos de Coortes , Fezes/microbiologia , Feminino , Doenças Transmitidas por Alimentos/microbiologia , Gastroenterite/epidemiologia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Água do Mar/microbiologia , Sorotipagem , Frutos do Mar/microbiologia , Temperatura , Vibrio parahaemolyticus/classificação
8.
Clin Infect Dis ; 42(3): 329-34, 2006 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-16392076

RESUMO

BACKGROUND: In June 1998, we investigated one of the largest foodborne outbreaks of enterotoxigenic Escherichia coli gastroenteritis reported in the United States. METHODS: We conducted cohort studies of 11 catered events to determine risk factors for illness. We used stool cultures, polymerase chain reaction, and serologic tests to determine the etiologic agent, and we conducted an environmental inspection to identify predisposing conditions and practices at the implicated establishment. RESULTS: During 5-7 June, the implicated delicatessen catered 539 events attended by >16,000 people. Our epidemiological study of 11 events included a total of 612 attendees. By applying the median prevalence of illness (20%) among events with ill attendees to the total number of events with any ill attendees, we estimate that at least 3300 persons may have developed gastroenteritis during this outbreak. Multiple food items (potato salad, macaroni salad, egg salad, and watermelon) were associated with illness, all of which required extensive handling during preparation. Enterotoxigenic Escherichia coli serotype O6:H16 producing heat-labile and heat-stable toxins was isolated from the stool specimens from 11 patients. Eight patients with positive stool culture results, 11 (58%) of 19 other symptomatic attendees, and 0 (0%) of 17 control subjects had elevated serum antibody titers to E. coli O6 lipopolysaccharide. The delicatessen had inadequate hand-washing supplies, inadequate protection against back siphonage of wastewater in the potable water system, a poorly draining kitchen sink, and improper food storage and transportation practices. CONCLUSIONS: In the United States, where enterotoxigenic Escherichia coli is an emerging cause of foodborne disease, enterotoxigenic Escherichia coli should be suspected in outbreaks of gastroenteritis when common bacterial or viral enteric pathogens are not identified.


Assuntos
Diarreia/epidemiologia , Diarreia/microbiologia , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Adulto , Estudos de Coortes , Surtos de Doenças , Feminino , Microbiologia de Alimentos , Gastroenterite/epidemiologia , Gastroenterite/microbiologia , Humanos , Illinois/epidemiologia , Masculino , Pessoa de Meia-Idade , Restaurantes , Fatores de Risco , Fatores de Tempo
9.
Am J Prev Med ; 30(3): 252-7, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16476642

RESUMO

BACKGROUND: The incidence of diarrheal disease among cruise ship passengers declined from 29.2 cases per 100,000 passenger days in 1990 to 16.3 per 100,000 passenger days in 2000. In 2002, the Vessel Sanitation Program of the Centers for Disease Control and Prevention reported 29 outbreaks (3% or more passengers ill) of acute gastroenteritis on cruise ships, an increase from 3 the previous year. This analysis of gastroenteritis on cruise ships, conducted in 2005, details the increase in outbreak incidence rates during 2001 through 2004. METHODS: Using Gastrointestinal Illness Surveillance System data, investigators evaluated incidence rates of gastroenteritis on cruise ships calling on U.S. ports, carrying 13 or more passengers, by cruise length and reporting region during the study period. The investigators also evaluated the association between inspection scores, and gastroenteritis incidence and the frequency of outbreaks in 2001 through 2004. RESULTS: During the study period, the background and outbreak-associated incidence rates of passengers with acute gastroenteritis per cruise were 25.6 and 85, respectively. Acute gastroenteritis outbreaks per 1000 cruises increased overall from 0.65 in 2001 to 5.46 in 2004; outbreaks increased from 2 in 2001 to a median of 15 per year in 2002-2004. Median ship inspection scores remained relatively constant during the study period (median 95 on a 100-point scale), and were not significantly associated with either gastroenteritis incidence rates (risk ratio, 1.00; 95% confidence interval, 0.98-1.02) or outbreak frequency (Spearman's coefficient, 0.01, p=0.84). CONCLUSIONS: Despite good performance on environment health sanitation inspections by cruise ships, the expectation of passenger cases of gastroenteritis on an average 7-day cruise increased from two cases during 1990-2000 to three cases during the study period. This increase, likely attributable to noroviruses, highlights the inability of environmental programs to fully predict and prevent risk factors common to person-to-person and fomite spread of disease.


Assuntos
Diarreia/epidemiologia , Surtos de Doenças , Exposição Ambiental/prevenção & controle , Gastroenterite/epidemiologia , Gestão de Riscos , Saneamento/normas , Navios/normas , Doença Aguda , Controle de Doenças Transmissíveis/normas , Diarreia/microbiologia , Diarreia/prevenção & controle , Surtos de Doenças/estatística & dados numéricos , Gastroenterite/microbiologia , Gastroenterite/prevenção & controle , Humanos , Incidência , Distribuição de Poisson , Vigilância da População , Saneamento/métodos , Navios/estatística & dados numéricos , Fatores de Tempo , Viagem , Estados Unidos/epidemiologia , United States Public Health Service
10.
One Health ; 2: 144-149, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28616489

RESUMO

Live poultry-associated salmonellosis is an emerging public health issue in the United States. Public and animal health officials collaborated to investigate one of the largest (356 cases, 39 states) of these outbreaks reported to date. A case was defined as illness in a person infected with the outbreak strain of Salmonella Typhimurium with illness onset between 1 March and 22 October 2013. The median patient age was seven years (range: < 1-87 years); 58% of ill persons were children ≤ 10 years, 51% were female, 25% were hospitalized; 189 (76%) of 250 patients reported live poultry exposure in the week before illness; and 149 (95%) of 157 reported purchasing live poultry from agricultural feed stores. Traceback investigations identified 18 live poultry sources, including 16 mail-order hatcheries. Environmental sampling was conducted at two mail-order hatcheries. One (2.5%) of 40 duplicate samples collected at one hatchery yielded the outbreak strain. Live poultry are an important source of human salmonellosis, particularly among children, highlighting the need for educational campaigns and comprehensive interventions at the mail-order hatchery and agricultural feed store levels. Prevention and control efforts depend on a One Health approach, involving cooperation between public and animal health officials, industry, health professionals, and consumers.

11.
Genome Announc ; 3(3)2015 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-26044422

RESUMO

Enterotoxigenic Escherichia coli (ETEC) is an important cause of diarrhea in children under the age of 5 years and in adults living in developing countries, as well as in travelers to these countries. In this announcement, we release the draft whole-genome sequences of 10 ETEC serogroup O6 strains.

12.
Clin Lab Med ; 35(2): 273-88, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26004642

RESUMO

Vibriosis is a group of intestinal and extraintestinal infections caused by marine-dwelling bacteria of the genus Vibrio. Infections range from indolent illnesses to fulminant diseases, including cholera and necrotizing fasciitis. Most illnesses result from direct contact with the marine environment or consumption of shellfish, especially oysters. In the United States vibrio infections are increasing but are underreported because of lack of clinical recognition and appropriate detection in the microbiology laboratory. Recent advances to aid in the detection and identification of vibrio illnesses in the laboratory include rapid identification tests, new media, and molecular identification systems.


Assuntos
Doenças Transmitidas por Alimentos/microbiologia , Alimentos Marinhos/microbiologia , Vibrioses/diagnóstico , Vibrio/isolamento & purificação , Gastroenterite/microbiologia , Humanos , Manejo de Espécimes , Estados Unidos , Vibrio/patogenicidade , Vibrio/fisiologia , Vibrioses/complicações , Vibrioses/epidemiologia , Vibrioses/microbiologia
13.
Front Microbiol ; 6: 204, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25852665

RESUMO

Vibrio parahaemolyticus is an aquatic halophilic bacterium that occupies estuarine and coastal marine environments, and is a leading cause of seafood-borne food poisoning cases. To investigate the environmental reservoir and potential gene flow that occurs among V. parahaemolyticus isolates, the virulence-associated gene content and genome diversity of a collection of 133 V. parahaemolyticus isolates were analyzed. Phylogenetic analysis of housekeeping genes, and pulsed-field gel electrophoresis, demonstrated that there is genetic similarity among V. parahaemolyticus clinical and environmental isolates. Whole-genome sequencing and comparative analysis of six representative V. parahaemolyticus isolates was used to identify genes that are unique to the clinical and environmental isolates examined. Comparative genomics demonstrated an O3:K6 environmental isolate, AF91, which was cultured from sediment collected in Florida in 2006, has significant genomic similarity to the post-1995 O3:K6 isolates. However, AF91 lacks the majority of the virulence-associated genes and genomic islands associated with these highly virulent post-1995 O3:K6 genomes. These findings demonstrate that although they do not contain most of the known virulence-associated regions, some V. parahaemolyticus environmental isolates exhibit significant genetic similarity to clinical isolates. This highlights the dynamic nature of the V. parahaemolyticus genome allowing them to transition between aquatic and host-pathogen states.

14.
Genome Announc ; 2(6)2014 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-25523765

RESUMO

Entertotoxigenic Escherichia coli (ETEC) is a major cause of global diarrhea, resulting in approximately 200 million occurrences and 300,000 to 400,000 deaths annually, primarily in children under the age of five. Here, we announce the release of the draft genomes of 10 ETEC isolates belonging to serogroup O6.

15.
Genome Announc ; 2(3)2014 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-24926061

RESUMO

We report here the draft genome sequences of nine enteropathogenic Escherichia coli (EPEC) strains isolated from children in Kenya who died during hospitalization with diarrhea. Each of the isolates possess the EPEC adherence factor (EAF) plasmid encoding the bundle-forming pilus, which is characteristic of EPEC. These isolates represent diverse serogroups and EPEC phylogenomic lineages.

18.
J Clin Microbiol ; 45(1): 134-40, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17093013

RESUMO

Vibrio, a diverse genus of aquatic bacteria, currently includes 72 species, 12 of which occur in human clinical samples. Of these 12, three species--Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus-account for the majority of Vibrio infections in humans. Rapid and accurate identification of Vibrio species has been problematic because phenotypic characteristics are variable within species and biochemical identification requires 2 or more days to complete. To facilitate the identification of human-pathogenic species, we developed a multiplex PCR that uses species-specific primers to amplify gene regions in four species (V. cholerae, V. parahaemolyticus, V. vulnificus, and V. mimicus). The assay was tested on a sample of 309 Vibrio isolates representing 26 named species (including 12 human pathogens) that had been characterized by biochemical methods. A total of 190 isolates that had been identified as one of the four target species all yielded results consistent with the previous classification. The assay identified an additional four V. parahaemolyticus isolates among the other 119 isolates. Sequence analysis based on rpoB was used to validate the multiplex results for these four isolates, and all clustered with other V. parahaemolyticus sequences. The rpoB sequences for 12 of 15 previously unidentified isolates clustered with other Vibrio species in a phylogenetic analysis, and three isolates appeared to represent unnamed Vibrio species. The PCR assay provides a simple, rapid, and reliable tool for identification of the major Vibrio pathogens in clinical samples, and rpoB sequencing provides an additional identification tool for other species in the genus Vibrio.


Assuntos
RNA Polimerases Dirigidas por DNA/genética , Reação em Cadeia da Polimerase/métodos , Análise de Sequência de DNA , Vibrio/classificação , Técnicas de Tipagem Bacteriana , Primers do DNA , Humanos , Dados de Sequência Molecular , Filogenia , Especificidade da Espécie , Vibrio/genética , Vibrio/isolamento & purificação , Vibrio/patogenicidade , Vibrioses/microbiologia , Vibrio cholerae/classificação , Vibrio cholerae/genética , Vibrio cholerae/isolamento & purificação , Vibrio mimicus/classificação , Vibrio mimicus/genética , Vibrio mimicus/isolamento & purificação , Vibrio parahaemolyticus/classificação , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/isolamento & purificação , Vibrio vulnificus/classificação , Vibrio vulnificus/genética , Vibrio vulnificus/isolamento & purificação
19.
J Clin Microbiol ; 45(4): 1133-9, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17301274

RESUMO

Vibrio parahaemolyticus is a halophilic bacterium capable of causing food- and waterborne gastroenteritis, wound infections, and septicemia in humans. The organism has recently received increasing attention, as the emergence of a new clone, V. parahaemolyticus O3:K6, has resulted in the first documented pandemic spread of V. parahaemolyticus. We used microarray analyses to explore the presence of known virulence factors and genetic markers thought to be specific for V. parahaemolyticus O3:K6 and its clonal derivatives. Analyses of 48 human clinical isolates collected between 1997 and 2005 revealed that the V. parahaemolyticus chromosome 2 type III secretion system is not specifically associated with pandemic strains and can be found in tdh-negative (i.e., Kanagawa-negative) clinical isolates. These results highlight the genetic dynamism of V. parahaemolyticus and aid in refining the genetic definition of the pandemic group members.


Assuntos
Vibrioses/microbiologia , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/patogenicidade , Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , DNA Bacteriano/análise , DNA Bacteriano/genética , Genes Bacterianos , Genótipo , Proteínas Hemolisinas/genética , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Transporte Proteico/genética , Vibrio parahaemolyticus/classificação , Vibrio parahaemolyticus/isolamento & purificação , Virulência/genética
20.
Proc Natl Acad Sci U S A ; 102(52): 19109-14, 2005 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-16354840

RESUMO

The morbidity and mortality associated with Vibrio-mediated waterborne diseases necessitates the development of sensitive detection technologies that are able to elucidate the identity, potential pathogenicity, susceptibility, and viability of contaminating bacteria in a timely manner. For this purpose, we have designed a single multiplex PCR assay to simultaneously amplify 95 diagnostic regions (encompassing species/serogroup-specific, antimicrobial resistance, and known toxin markers) and combined it with a long oligonucleotide microarray to create a platform capable of rapidly detecting and discriminating the major human pathogenic species from the genus Vibrio: V. cholerae, V. parahaemolyticus, V. vulnificus, and V. mimicus. We were able to validate this strategy by testing 100 geographically and temporally distributed isolates and observed an excellent concordance between species- and serotype-level microarray-based identification and traditional typing methods. In addition to accurate identification, the microarray simultaneously provided evidence of antibiotic resistance genes and mobile genetic elements, such as sulfamethoxazole-trimethoprim constins and class I integrons, and common toxin (ctxAB, rtxA, hap, hlyA, tl, tdh, trh, vvhA, vlly, and vmhA) and pathogenicity (tcpA, type III secretion system) genes that are associated with pathogenic Vibrio. The versatility of this method was further underscored by its ability to detect the expression of known toxin and virulence genes from potentially harmful viable but nonculturable organisms. The results suggest that this molecular identification method provides rapid and definitive information that would be of value in epidemiological, environmental, and health risk assessment surveillance.


Assuntos
Anti-Infecciosos/farmacologia , Análise de Sequência com Séries de Oligonucleotídeos , Vibrio/genética , Técnicas de Cultura de Células/métodos , DNA Bacteriano/metabolismo , Variação Genética , Genótipo , Humanos , Integrons , Modelos Genéticos , Fenótipo , Reação em Cadeia da Polimerase , Fatores de Tempo , Vibrio/metabolismo , Vibrio/patogenicidade , Vibrioses/metabolismo
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