Abstract:
Background: Vegetables can be contaminated with a range of microbial contaminants and
pathogens and have long been known to serve as vehicles for transmission of infectious
microorganisms Thus, this study was aimed to assess antibiotic susceptibility patterns and
plasmid profile of microbial isolates from fresh vegetables collected in selected local market at
Jimma town, southwest Ethiopia from Feb to April, 2015.
Methods: A cross sectional study design was employed. A total of 150 fresh vegetable samples
were purchased in different days from different outlets in Jimma town, from open market and
groceries between Feb-April 2015. Equal numbers of vegetable types comprising lettuce,
cabbage, carrot, tomato, green pepper, was purchased from farmers and four purposively
selected local markets. For microbiological analyses, 25g of sample was aseptically weighed
and washed in 225ml of sterile 0.1% (w/v) bacteriological peptone water (Oxoid) for 3 minutes.
Appropriate serial dilutions of the suspension were plated on nutrient agar medium. Total plate
count and pathogens isolation was done. Antimicrobial susceptibilities test and plasmid profile
was performed.
Results: More than 80% of vegetable samples had total viable counts of greater
than106CFU/g with ranges of 105-107CFU/g. A total of 102 bacterial isolates of eight genera
were identified. Enterobacter spp. (21.60%) was the most dominant followed by Citrobacter
spp. (20.6%), Klebsiella spp. (18.6%), Salmonella spp. (11.8%), E. coli (10.8%), Proteus spp.
(9.8%), Staphylococcus spp. (4.9%), and Pseudomonas aeruginosa (2%). Ampicillin and
amoxicillin were highly resisted by more than 89% of microbial isolates. All the five S. aureus
isolates were sensitive to oxacillin and vancomycin but two isolates were intermediately
sensitive to erythromycin. Ciprofloxacillin was the least resisted drugs only 3.9 % whereas
oxytetracycline was resisted by 31.4 % of the isolates. Resistance to nitrofurantoin, nalidic
acid, streptomycin, chloramphenicol, cotrimoxazole, ceftriaxone, kanamycin and Gentamycin
were 30.4%, 26.5%, 18.6%, 12.7%, 10.8%, 10.8%, 7.8%, 4.9% respectively. Plasmid was
detected in 20 out of 91resistant isolate to at least one antibiotic.
Conclusion and Recommendation: - Occurrence of antimicrobial resistance and plasmid
carriage in bacterial populations in fresh vegetables at retails may constitute threats to
consumers, possibly via resistance transfer. Thus, these results suggest the necessity to follow
the hygienic practices in handling the vegetables.
