The prevalence of bacterial resistance in clinical, food, water and some environmental samples in Southwest Nigeria

The resistance pattern and mechanisms of bacterial isolates obtained from clinical origin, soil, industrial effluent, orange juice products and drinking water were studied using commonly used antibiotics. The microbial load of the water samples, industrial effluent and orange juice products were 1.0 × 10¹–2.25 × 10⁶, 2.15 × 10⁵, and 3.5 × 10⁴–2.15 × 10⁵ cfu mL^–1, respectively. The faecal coliform test revealed that only two out of twenty orange juice products had MPN of 2 and 20, the MPN of water ranged from 1–1800, while the effluent had MPN of 1800. The bacterial isolates that were isolated include E. coli, S. aureus, P. vulgaris, S. marcescens, S. pyogenes, B. cereus, B. subtilis, Micrococcus sp., Klebsiella sp., P. aeruginosa, and Enterobacter sp. Also, clinical and soil isolates of P. aeruginosa were used in the study. Among the eight antibiotics tested for resistance on five strains of each bacterium, seven different resistance patterns were observed among the bacterial isolates obtained from water, effluent and orange juice products. Among the clinical and soil isolates of P. aeruginosa, four multiple-drug resistance patterns were obtained. Thirty strains of E. coli and S. aureus were tested for -lactamase production and fourteen strains, seven each of E. coli and S. aureus that had high Minimum Inhibitory Concentration values (MIC) for both Amoxycillin and Cloxacillin were positive.