Environmental Listeria monocytogenes isolates from Ado-Ekiti, Nigeria and its antibiotic resistance pattern
Keywords:
Listeria monocytogenes, vegetable, cow dung, antibiotic resistance, environmental isolates.Abstract
Incidence of Listeria monocytogenes in cow manure, agricultural soil, and common vegetables sold in major
markets in Ado-Ekiti, Nigeria was determined. Antibiotic resistant pattern of the isolates was examined by
paper disk assay. A total of 196 environmental samples were cultured on a selective medium out of which 153
(78.1%) were positive for L. monocytogenes. Erythromycin was the most effective antibiotic against the isolates
with the least resistance (28.1%) while chloramphenicol proved to be least effective with resistant of 52.29%.
The multiple-antibiotic resistant pattern of the isolates showed augumentin/amoxicillin (33.3%),
augumentin/erythromycin (24.18%), and cotrimoxazole/ chloramphenicol/amoxicillin (28.8%) to be most
prominent. The least value was observed in cloxacilin/cotrimoxazole/gentamycin with 15.34%. The modal
values of the Minimum Inhibitory Concen-trations (MICs) of the antibiotics to the isolates range between 4.0
and >16.0 μg/ml. cotrimoxazole and gentamicin recorded the highest MIC compared with other antibiotics.
