Occurrence of Multi-drug Resistant Bacteria in Some Selected Street Food Samples

Antimicrobial resistance is a subject of great concern in the public health. The prevalence of antimicrobial resistance among food pathogens has increased during recent decades.

Studying the incidence and antibiotic resistance pattern of bacterial species isolated from fish and vended street fruits.

Eleven fish swabs and thirteen sliced fruit samples were collected and prepared for isolation of bacterial species through inoculation onto selective and non-selective nutrient media. The grown colonies were purified through subculturing on nutrient agar plates then identified by morphological and biochemical methods. The obtained pure cultures were then kept on nutrient agar slants. Testing antibiotic resistance of the isolated bacterial strains was studied by Kirby-Bauer disk diffusion method on Mueller Hinton agar using ten antibiotics belonging to different classes. The resultant inhibition zone was interpreted according to Clinical Laboratory Standard Institute.

Twenty-eight bacterial cultures were isolated from the collected food samples. The conventional identification using morphological and biochemical methods of these cultures revealed presence of three Gram positive species; Staphylococcus aureus, Streptococcus sp. and Bacillus subtilis in addition to four Gram negative; Escherichia coli, Brucella sp., Enterococcus faecalis and Proteus mirabilis. The incidence of the obtained bacterial species was arranged as 29.16% for both S. aureus and E. faecalis followed by Brucella sp. 16.66%; B. subtilis & E. coli 12.5% then Streptococcus sp. and P. mirabilis with an incidence of 8.33% each. Testing antibiotic resistance pattern of seven bacterial species against ten antibiotics showed that, among three Gram positive bacterial species, only one (33.33%) strain S. aureus exhibited resistance to six antibiotics; amoxicillin, erythromycin, ciprofloxacin, ceftriaxone, fluconazole and dicloxacillin. Among four Gram negative bacterial strains only one (25.0%) strain Enterococcus faecalis exhibited resistance to eight antibiotics; amoxicillin, streptomycin, chloramphenicol, cotrimoxazole, ciprofloxacin, ofloxacin, sparfloxacin and cloxacillin.

Occurrence of multi-drug resistant bacteria in fish and vended street fruits poses not only risk of disease to the foods but public health hazard to food handlers and consumers in general. Also the result of this study recommended augmentin and cephazolin as good choice antibiotics for treatment of infection in the study area.