Beta Lactamase Resistome in culturable bacterial isolates from drinking water of Pakistan

Abstract

Antibiotic resistance poses one of the greatest threats in the world. Misuse of antibiotics has resulted in the emergence of resistant bacteria in every part of the world. We collected isolates from drinking water from 28 cities across Pakistan and determined their antibiotic sensitivity profile against 14 beta lactam including 3rd & 4th generation cephalosporins, carbapenums and penicillin, vancomycin and tigecyclin by disc diffusion assay and found that more than 83 percent of the bacteria were resistant against 5 or more tested antibiotics. A high prevalence in resistance against 4th generation cephalosporin cefepime 73%, vancomycin (54%), impenum (32.8%) and the highest in cefexime (89%) was found in the water samples. In addition, we determined the prevalence of bla CTXM15, bla SHV and bla TEM beta lactamases by polymerase chain reaction and found that 34%, 22% and 98% of the isolated bacterial strains were positive for the three genes respectively. 40 percent of the strains which showed resistance against vancomycin were positive for Van A gene. Highest level of resistance was found in the Sahiwal disctrict, Talagang, Kasur and Nathiagali region. On the basis of this study, it is observed that bacteria in the drinking ground lake and stream waters are resistant against beta lactams and vancomycin. However, use of antibiotics in agriculture and husbandry, as well as industrialization seems to cause increased resistance in the environment bacteria