Prevalence of Beta Lactamase Antibiotic Resistance Genes (ARGs) in Bacterial Isolates from Different Soils of Pakistan

Abstract

Ever since the discovery of the first antibiotic, 60 years ago, these drugs have been subjected to excessive use and misuse resulting in the emergence of resistant bacteria against all the classes of antibiotics in the current clinical use. We collected isolates from soils of 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 81 percent of the bacteria were resistant against 5 or more tested antibiotics. A high prevalence in resistance against 4th generation cephalosporin cefepime 73%, vancomycin (64.7%), Imipenum (30.4%) and the highest in cefexime (91%) were found in the soil samples. In addition, we determined the prevalence of bla CTXM15, bla SHV and bla TEM beta lactamases by polymerase chain reaction and found that 23%, 17% and 96% of the isolated bacterial strains were positive for the three genes respectively. Highest level of resistance was found in the Rawalpindi District and in central Punjab region. On the basis of this study, it is observed that bacteria in the soil samples are resistant against beta lactams, especially to 3rd generation cephalosporin’s. However, use of antibiotics in agriculture and husbandry, as well as industrialization seems to cause increased resistance in the environment bacteria.