Phenotypic and Molecular Analysis of Antibiotic Resistance in Lactobacilli of Poultry Origin from Lahore, Pakistan

Acquired antibiotic resistance in lactobacilli poses a significant threat to public health.This study presents phenotypic and molecular analysis of antibiotic resistance in lactobacilli of poultry gut origin.A total of 105 Lactobacillus spp.isolates including 59 from indigenous and 46 from commercial poultry were recovered.Lactobacilli were identified by genus specific polymerase chain reaction (PCR) targeting 16SrDNA-23S rDNA inter-spacer region.Minimum inhibitory concentrations of different antibiotics were determined by broth micro dilution method.Antibiotic resistance genes for erythromycin [erm(B)] and tetracycline [tet(M)] were amplified by PCR and sequenced for homology analysis.Antibiotic resistance against cephradine (67.39% vs 55.93%), cefuroxime (100% vs 77.96%), erythromycin (86.95% vs 38.98%), tetracycline (41.30% vs 32.2%), ciprofloxacin (91.30% vs 84.74%), levofloxacin (97.82% vs 81.35%) and ofloxacin (95.65% vs 88.13%) were comparatively higher in lactobacilli of commercial poultry origin as compared to indigenous poultry.Resistance against ampicillin was slightly higher in back yard (49.15%) as compared to commercial poultry (43.47%).Overall, a high level resistance against cefuroxime (87.61%), levofloxacin (88.57%), ofloxacin (91.42%), ciprofloxacin (87.61%), and moderate level resistance against cephradine (60.95%), ampicillin (46.66%), tetracycline (36.19%) and erythromycin (60%) was observed.Erythromycin and tetracycline resistant genes [erm (B), and tet(M), respectively] were successfully amplified from phenotypically resistant lactobacilli.Sequencing analysis revealed that erm(B) gene had >99% similarity with erm(B) gene of Enterococcus faecium while tet(M) had >99% similarity with tet(M) of E. coli.It is concluded that lactobacilli of poultry gut origin contain acquired antibiotic resistance and its transmission to other bacterial strains is a significant threat to public health.