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.
