RESUMO
The source and routes of diarrheagenic Escherichia coli (DEC) remain poorly understood. To investigate the involvement of domestic animals in the dissemination of DEC, the prevalence of DEC in foods and fecal specimens from cattle, pigs, chickens, healthy carriers, and patients in Osaka and Hyogo, Japan was investigated using a multiplex real-time Polymerase Chain Reaction assay. The most abundant virulence genes were astA and eae, which had a prevalence 46.8% and 27.4%, respectively. Additionally, stx1 (26.6%) and stx2 (45.9%) were prevalent in cattle feces, while est (8.5%) and elt (7.6%) were prevalent in pig feces. afaB was the second-most prevalent gene in patients and healthy carriers, and it had detection rates of 5.1% and 8.1%, respectively. In contrast, afaB was not detected in animal feces or foods, except for three porcine fecal samples. The aggR gene was more prevalent in humans than in foods or animal feces. Both Shiga toxin-producing E. coli and atypical enteropathogenic E. coli carried by cattle may be sources for diarrheal diseases in humans. Pigs may be a source for human enterotoxigenic E. coli infections, whereas humans are expected to be the reservoir for diffusely adhering E. coli, enteroaggregative E. coli, and enteroinvasive E. coli.
Assuntos
Portador Sadio/epidemiologia , Portador Sadio/veterinária , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Microbiologia de Alimentos , Animais , Portador Sadio/microbiologia , Bovinos , Galinhas , Escherichia coli/genética , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Humanos , Japão/epidemiologia , Reação em Cadeia da Polimerase Multiplex , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Suínos , Fatores de Virulência/genéticaRESUMO
The etiological roles of diarrheagenic Escherichia coli (DEC), including enteroaggregative E. coli (EAggEC), diffusely adherent E. coli (DAEC) and EAST1EC--a strain of E. coli that possesses no diarrheagenic characteristics other than the EAggEC heat-stable toxin 1 (EAST1) gene--remain controversial. To clarify the prevalence of DEC among healthy individuals in Osaka City, Japan, and to compare the virulence properties of strains previously isolated from diarrheal patients, fecal specimens were examined for DEC. Isolation rates of Shiga toxin-producing E. coli, enterotoxigenic E. coli, and EAggEC were significantly lower among healthy adults than sporadic adult patients. There were no differences in enteropathogenic E. coli (EPEC), DAEC and EAST1EC between patients and healthy carriers. Subtyping of the intimin gene (eae) of EPEC, and measuring the IL-8 inductivity of DAEC on epithelial cells could provide criteria to distinguish strains in diarrheal patients from those in healthy carriers. Proper criteria should be established in order to diagnose subtypes of DEC as causative agents.
Assuntos
Portador Sadio/epidemiologia , Portador Sadio/microbiologia , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/isolamento & purificação , Adesinas Bacterianas/genética , Adulto , Impressões Digitais de DNA/métodos , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Proteínas de Escherichia coli/genética , Fezes/microbiologia , Genótipo , Humanos , Japão/epidemiologia , Prevalência , Fatores de Virulência/genética , Adulto JovemRESUMO
A population-based study of Mycobacterium tuberculosis isolated from homeless tuberculosis patients was performed during 2002-2004 in Osaka City, Japan. The data show that the ancient Beijing subfamily was predominant, whereas clustered isolates based on refined variable number of tandem repeats genotyping (19 loci) mainly belonged to the modern Beijing subfamily, suggesting its increased transmissibility.
