Abstract:
Diarrheagenic E. coli (DEC) are among re-emerging bacterial strains associated with
outbreaks of severe diarrhoea and multiple drug resistance. Our objectives were to
characterize DEC among diarrheal patients attending Thika Level 5 Hospital and
determine their antimicrobial susceptibility patterns. A cross-sectional study was
conducted. Consenting patients of all ages seeking diarrhoea treatment at the hospital
from April to July 2014 were recruited. A structured questionnaire was used to
collect clinical and epidemiological information. Stool samples were collected,
inoculated on bacterial differential media for growth of enteric pathogens and
antimicrobial susceptibility patterns of DEC isolates determined. Isolates were
characterized by Polymerase Chain Reaction for the presence of virulence properties.
A total of 402 stool samples were cultured. E. coli was isolated from 269, of which
72 (27%) were DEC; 60 (83.3%) enteroaggregative E. coli (EAEC), 6 (8.3%)
enteropathogenic E. coli (EPEC) and 6 (8.3%) enterotoxigenic E. coli (ETEC). Of
the DEC affected patients, 58% were female, median age was 8 (IQR: 2-28) years,
75% did not boil water and 100% did not treat water. Twenty five (35%) patients
with DEC were under-five years of age. Drinking un-boiled water (OR: 2.51, 95%
CI: 1.36-4.61) was associated with having DEC. Being under-five years was
associated with EAEC (P<0.05). Of the 60 EAEC strains, 24 (40%) EAEC isolates
were positive for both aggR and aspU genes, while 36 (60%) were positive for aspU
gene only. EPEC eae (100%, n=6) and ETEC elt (100%, n=6). All DEC isolates
were sensitive to cefoxitin, meropenem, amikacin, gentamicin and ciprofloxacin.
They were resistant to ampicillin (92%), trimethoprim-sulfamethoxazole (92%) and
amoxicillin-clavulanic acid (85%). Majority of diarrhea patients were female and
predominant DEC strain were EAEC. Drinking un-boiled water was associated with
DEC infection. High level of resistance to ampicillin, trimethoprimsulfamethoxazole and amoxicillin-clavulanic acid were observed. All isolates were
sensitive to ciprofloxacin and gentamicin.
