Antibiotic Resistance Pattern of Staphylococcus aureus Isolated from Seafood

Staphylococcus aureus is a pathogen known to cause hospital, community acquired and foodborne illness with varying susceptibility to antibiotics. The selective pressure due to the use of antibiotics along with horizontal and vertical gene transfer has resulted in the evolution of multidrug resistant S. aureus. The purpose of the study was to determine the antibiotic resistance pattern in S. aureus isolated from seafood of Kerala, India. One hundred and thirty three S. aureus isolates obtained during 2012 to 2015 were included in this study. Antibiotic susceptibility testing was performed with a set of 20 antibiotics representing eleven classes of antibiotics by standard disk diffusion assay. The study revealed that 90.9% of the S. aureus isolates were resistant to at least one class of antibiotics. Resistance was found among 33.8, 27.8, 17.3, 6.8, 3.8, 0.7 and 0.7% isolates to one, two, three, four, five, six and eight classes of antibiotics respectively. Multidrug resistance was found in 29.3% of the S. aureus isolates with resistance to antibiotics ranging from 3 to 8 classes of antibiotics. The study reveals that S. aureus isolates were sensitive to aminoglycosides and phenicols.