37 / 46
Volume 2
Journal of Environmental Research
Page 84
JOINT EVENT
July 26-27, 2018 Rome, Italy
&
6
th
Edition of International Conference on
Water Pollution & Sewage Management
4
th
International Conference on
Pollution Control & Sustainable Environment
Molecular characterization of extended spectrum beta-lactamase producing
Escherichia coli
O157:H7
from three selected rivers in Osun State, Nigeria
M A Bisi Johnson
1
, Adedeji A A
1
and
Sulaiman A A
2
1
Obafemi Awolowo University, Nigeria
2
Institute of Human Virology, Nigeria
E
scherichia coli
O157:H7 is a known pathogenic microorganism associated with contaminated water and food. The pathogen
is implicated in diseases with severe morbidity and increasing death rate and resistant of the bacteria to antibiotics such as
cephalosporins have complicated health interventions. Water samples from three selected rivers were investigated as a potential
reservoir for extended spectrum beta lactamase (ESBL) - producing
E. coli
O157:H7 using phenotypic (culture-based) and
molecular methods. Antibiotic susceptibility was determined using Kirk Bauer double disc method. Double disc synergy test
was determined between a disc of amoxicillin-clavulanate (20µg/10µg) (Augmentin) and a 30-µg disc of each third generation
cephalosporin antibiotic. ESBL positive isolates were then subjected to specific Polymerase Chain Reaction (PCR). A total of 65
isolates were confirmed as
E. coli
O157: H7. Among these, 98% were resistant to cefixime, ofloxacin (93%), cefuroxime (87%),
augmentin (86%), cefotaxime (80%) and ciprofloxacin (43%). Of the 64 isolates resistant to third generation cephalosporins,
58 were ESBL positive phenotypically while, but at least 2 genes coexisted in 6 of the isolates. Of the 52 isolates with confirmed
ESBL genes, ESBL type
bla
SHV was found to be dominant (40%),
bla
TEM 36% and
bla
CTX 3%. The rivers sampled were
identified to harbour resistant
E. coli
O157:H7 and therefore, strategies should be employed to reduce the dissemination of
ESBL producing bacteria in the aquatic sources which may threaten human life, animal and surrounding environment.
jumokade@yahoo.co.ukJ Environ Res 2018, Volume: 2