Studies on diarrheagenic Escherichia coli isolated from children with diarrhea in Myanmar

Abstract

invasion-associated locus of the invasion plasmid found in EIEC; lt, heat-labile enterotoxin; NB, nutrient broth; PCR, polymerase chain reaction; pCVD, representative plasmid of EAEC; SDS, sodium dodecyl sulfate; SSC, standard saline citrate; stI, heat-stable enterotoxin I; stII, heat-stable enterotoxin II; Stx1, shiga-like toxin 1; Stx2, shiga-like toxin 2; UV, ultraviolet.Key words children, diarrhea, E. coli, Myanmar. ABSTRACTEscherichia coli isolates from 217 children in Myanmar with diarrhea were investigated for the presence of virulence genes related to diarrhea by colony hybridization and PCR. The genes examined were lt, stI, stII, stx1, stx2, eae, bfp, pCVD (which is the representative gene of plasmid of pCVD of EAEC), and ial (which is invasion-associated locus of the invasion plasmid found in EIEC). Isolates from 47 of 217 children (21.7%) possessed virulence genes characteristic of diarrheagenic E. coli. No instance was found of co-existence of different E. coli strains with different virulence genes in the same patient. Diarrheagenic E. coli are currently classified into five categories based on their virulence markers: ETEC, EHEC, EPEC, EAEC, and EIEC. Of the 47 isolates examined, 30 were EAEC, 12 were EPEC and 5 were ETEC. Susceptibility tests for antimicrobial agents showed that almost all diarrheagenic isolates were resistant to penicillin, tetracycline and streptomycin. However, the majority of strains were sensitive to cephalexin, nalidixic acid and norfloxacin. In particular, 42 of the 47 isolates were sensitive to norfloxacin, which is a fluoroquinolone. This study shows EAEC and EPEC are responsible for sporadic diarrhea in Myanmar and fluoroquinolones appear to be effective in the treatment of these patients.

Prevalence and molecular characterization of Shiga toxin-producing escherichia coli isolates from human and sheep in Al-Madinah Al-Munawarah

“…34,35 Previous studies have shown a certain degree of homogeneity for the presence of virulence factors within STEC serotypes. 36 The present study showed that stx 1 was significantly more frequent in isolates from O157 and non-O157 serotypes, followed by stx 2 and none of the strains lack either stx 1 or stx 2 . ehxA was observed to be frequent between isolates from O157 serotypes, but completely absent in non-O157 serotypes.…”

A study of virulence and antimicrobial resistance pattern in diarrhoeagenic Escherichia coli isolated from diarrhoeal stool specimens from children and adults in a tertiary hospital, Puducherry, India

“…In recent years, EAEC has emerged as diarrhoeal agent causing acute and chronic diarrhea in all age groups though it was once known to infect primarily newborns and immunocompromised patients [ 4 ]. Studies conducted in Mexico, Bolivia, Nicaragua, and Myanmar found that EAEC was the most common among all the DEC pathotypes [ 14 , 26 – 28 ]. On the contrary, in our study, EPEC was the most common, similar to the findings of the studies conducted in Israel, Norway [ 29 , 30 ].…”

<I>ESCHERICHIA COLI</I> PATHOTYPES ASSOCIATED WITH DIARRHEA IN HUMAN AND DOMESTIC ANIMALS

“…Detection of O-serogroup was performed using a commercially available Oserogrouping Kit (Denka Seiken, Tokyo, Japan) (Takahashi et al, 2008). The Flagellar phase inversion was carried out using the standard Craigie tube technique by passage through semi-solid agar containing the appropriate flagellar antis era (Davies and Wray, 1997).…”