Study on the genotype and epidemic characteristics of diarrheagenic Escherichia coli isolated from diarrheal patients in Beijing / 中华流行病学杂志

ABSTRACT

Objective To understand the distribution of virulence gene and the epidemiological characteristics of diarrheagenic Escherichia(E.) coli (DEC) from diarrheal patients in Beijing. Methods Stool specimens from diarrheal patients were cultured which were collected from the hospitals under sentinel surveillance program,during 2012-2013. DNA was examined by real-time PCR. Results 253 out of 6 370 specimens were positive for DEC detection with the rate as 4.0%. A total number of 262 DEC strains were isolated. Two different pathotypes of DEC strains with mixed infection,were isolated from 9 specimens. Different pathotypes would show the following profiles42.8% for enteropathogenic E. coli (EPEC) including 42.0% atypical and 0.8% typical;38.9% for enterotoxigenic E. coli(ETEC)including 24.8%st positive,9.9%lt positive and 4.2%st and lt both positive;15.3% for enteroaggregative E. coli(EAEC);2.7% for enteroinvasive E. coli(EIEC);one strain STEC with serotype O26 ∶ K60. ETEC had obvious characteristics on age. All kinds of DEC were isolated throughout the year with seasonal fluctuation. Conclusion DEC isolates from diarrheal patients in Beijing were dominated by EPEC and ETEC,with atypical ones accounted for the majority of EPEC. One specimen was found under mixed infection. Pathotypes DEC were found to have different age and seasonal distributions.