TITLE:
Characterization of Multidrug Resistant Escherichia coli Isolates Recovered from Humans and Chickens, Trinidad and Tobago
AUTHORS:
Sandra Ashiboe-Mensah, Francis Dziva, Patrick Eberechi Akpaka, Caroline Mlambo, Abiodun A. Adesiyun
KEYWORDS:
Extended-Spectrum Beta-Lactamase (ESBL), Escherichia coli, PCR, Virulence Genes, Trinidad & Tobago
JOURNAL NAME:
Advances in Infectious Diseases,
Vol.6 No.4,
November
18,
2016
ABSTRACT: To characterize
extended-spectrum beta-lactamase (ESBL) and extra-intestinal pathogenic Escherichia coli (ExPEC) associated
virulence genes in E. coli isolates
from chickens and humans in Trinidad and Tobago. This cross sectional study was
conducted over a three-month period. A total of 471 E. coli isolates; 160 from
humans treated at a regional tertiary hospital and 311 from chicken caecal
samples from “pluck shops” in Trinidad & Tobago were identified using both conventional and
molecular microbiological methods. Phenotypic confirmation of ESBL producing E.
coli isolates from humans was by Microscan system (Siemens, USA) while the
double disk diffusion method was used for the chicken isolates. Polymerase
chain reaction (PCR) analysis was used to determine the ESBL and
ExPEC-associated virulence genes in representative human isolates and all
chicken isolates. From the 311 chicken E. coli isolates, 49.2% (153/311)
produced ESBL, while 56.3% (90/160) from humans were ESBL positive. All human
and chicken ESBL isolates were 100% susceptible to carbapenems and aminoglycosides
antimicrobials. PCR detected 21.1% blaCTX-M, 13.3% blaTEM and 7.8% blaSHV genes among E coli isolates from
humans compared to 0.6% blaCTX-M and 48.6% blaTEM genes in chickens. PCR analysis revealed diverse virulence profiles among
the isolates. There was a high occurrence rate of ExPEC-asso- ciated virulence genes in E. coli isolates from both humans and
chickens. However, the CTX-M-1 genes were most predominant in humans
while TEM occurred in chic- ken isolates. The diverse ESBL and virulence
associated gene profiles encountered in E. coli isolates from humans and
chickens on the surface depicts no similarity or relationships despite occurrence
in both cohort groups. Therefore E. coli strains from chickens and
humans require further investigation to determine their clonal relatedness or
transmission in the country.