Antimicrobial resistance of bacterial strains isolated from orange juice products

Abstract

Forty samples of twenty brands of sachet orange juice products were examined microbiologically. All 
the products were contaminated with bacteria and yeasts. The organisms encountered include 
Saccharomyces cerevisiae, Saccharomyces sp, Rhodotorula sp, Bacillus cereus, Bacillus subtilis, 
Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes and Micrococcus sp. The 
resistances of thirty bacterial strains isolated from orange juice products to the commonly used 
antibiotics were studied. About 66.67% of the isolates were resistant to augmentin and amoxycillin; 
63.33% to cotrimoxazole, 56% to cloxacillin, and 23.33% to tetracycline. Resistances of 10, 6.67, and 
3.33% were obtained for gentamicin, erythromycin and chloramphenicol respectively. Among the eight 
antibiotics tested, seven patterns of drug resistance were obtained. Six out of these are multiple-drug 
resistance with number of antibiotics ranging between 2 to 8. While MIC of amoxycillin ranged between 
10-25mg/ml for the strains of E. coli, MIC of 10- 20mg/ml was obtained for the strains of S. aureus. The 
MIC for cloxacillin was 0.1-1.0mg/ml for E. coli strains, and 0.01-1.0mg/ml for S. aureus strains. In all, 
ten strains of the bacterial isolates had evidence for the production of -lactamases.