Antibiogram and plasmid profiling of beta-lactamase producing multi drug resistant Staphylococcus aureus isolated from poultry litter

Abstract

The occurrence of antibiotic resistant microorganisms in poultry litter is due to the increasing use of antibiotics. Poultry litter is used as a fertilizer for its high nutrient content. The presence of antibiotic resistant microorganisms in poultry litter makes its handling, amendment and application as fertilizer a challenging task. This study is designed to evaluate the antibiotic susceptibility and plasmid profiling of beta-lactamase producing multi-drug resistant Staphylococcus aureus in poultry litter. Sample collected from a poultry farm was screened for the presence of Staphylococcus aureus strains. The in vitro antibiotic susceptibility test by disk diffusion method were carried out in all the isolates. All the isolates were highly susceptible to oxacillin and gentamycin and intermediate for erythromycin and were completely resistant to vancomycin and penicillin. The isolated Staphylococcus aureus strains showed beta-lactamase activity which is the basis for the resistance to beta-lactum antibiotics. These strains when exposed to curing agent namely ethidium bromide, the beta-lactamase activity was lost. Results indicate that Staphylococcus aureus isolated from poultry litter are beta-lactamase producers and relatively resistant to commonly used antibiotics. The resistance among the isolated strains is found to be plasmid-mediated. The outcome of our present study exercises both usefulness in shaping the existing antibiotics prescription and thus helps to reduce or prevent the development of multiple drug resistant microorganism.