BACTERIOLOGICAL EVALUATION AND ANTIBIOTIC SUSCEPTIBILITY PROFILE OF ISOLATES FROM READY- TO- EAT FRIED FISH.

Abstract

The study was carried out to ascertain the level of bacterial contamination of ready-to-eat fried
fish hawked in Lapai metropolis of Niger state, Nigeria. Fried fish samples were collected from
two different markets in Lapai. The bacterial load of the samples was determined using the pour
plate technique. Bacteria growth was sub-cultured on MacConkey agar and Mannitol salt agar.
Identification and characterization of various isolates were based on Gram staining technique and
conventional biochemical tests. Results indicated that the mean bacteria population across the
two markets after sampling for two (2) months ranged from 7.0 x 104 to 8.4 x 106 cfu/mg. The
lowest bacteria population of 7.0 x104 cfu/mg occurred in the samples from the main market,
while the highest bacteria population of 8.4 x 106 cfu/mg occurred in the samples from Badeggi
market. Pseudomonas aeruginosa isolates had the highest distribution of 4 (44.5%), while
Streptococcus spp isolate had the least distribution of 1 (11.1%). Bacillus subtillis and
Staphylococcus aureus isolates had equal distribution of 2 (22.2%). Antibiotic susceptibility test
was conducted on the isolates, and the result showed that S. aureus was 100% resistant to all the
antibiotics used in the research study. Bacillus subtilis showed resistance to all the antibiotics,
except Levofloxacin and Rifampicin to which the isolates were susceptible by 50%.
Streptococcus spp was 100% resistant to Ampiclox, Erythromycin, Chloramphenicol,
Norfloxacin, Amoxil and Rifampicin, but showed 100% susceptibility to Gentamicin,
Levofloxacin, Ciproflox and Streptomycin. The isolates of P.aeruginosa were moderately
susceptible to all the antibiotics used, but resisted Ampiclox and Norfloxacin. The findings of
this research indicated that ready- to- eat foods are potential vehicles for transmitting food
borne illnesses, therefore, there is the need to develop practical strategies that would prevent
microbial contamination of street hawked foods.