Evaluation of multiplex polymerase chain reaction as an alternative to conventional antibiotic sensitivity test

This study was designed to evaluate the potential of the use of multiplex polymerase chain reaction (PCR) as an alternative to conventional antibiotic sensitivity test.

Isolates of Staphylococcus aureus (total = 36) from clinical cases presented to Teaching Veterinary Clinical Complex of College of Veterinary and Animal Sciences (CVAS), Navania, Udaipur, were characterized by morphological, cultural, and biochemical methods. Then, the isolates were further subjected to molecular characterization by PCR targeting S. aureus-specific sequence (107 bp). Phenotypic antibiotic sensitivity pattern was analyzed by Kirby-Bauer disc diffusion method against 11 commonly used antibiotics in veterinary medicine in and around Udaipur region. The genotypic antibiotic sensitivity pattern was studied against methicillin, aminoglycosides, and tetracycline targeting the gene mecA, aacA-aphD, and tetK by multiplex PCR.

There was 100% correlation between the phenotype and genotype of aminoglycoside resistance, more than 90% correlation for methicillin resistance, and 58.3% in the case tetracycline resistance.

As there is a good correlation between phenotype and genotype of antibiotic resistance, multiplex PCR can be used as an alternative to the conventional antibiotic susceptibility testing, as it can give a rapid and true prediction of antibiotic sensitivity pattern.