Prevalence and antibiogram of multidrug resistant Staphylococcus haemolyticus from various clinical samples in a tertiary care hospital in Hyderabad, India

Abstract

Background: Staphylococcus haemolyticus (S. haemolyticus) is one of the important organisms in hospital-acquired infections. This strain comprises many enzymes, cytolysins, and surface substances which contribute to its virulence. We in the present study tried to evaluate the prevalence of methicillin-resistant S. haemolyticus causing nosocomial infections in a Tertiary Care Hospital. Methods: A total of n = 95 non-repeated S. hemolyticus were isolated in the Department of microbiology out of n = 2116 various clinical specimen present. The strains collected were initially identified by colony morphology on Nutrient agar, Sheep blood agar, Chocolate agar, Uri Chrom agar, gram staining, catalase, coagulase (both slide coagulase and tube coagulase), mannitol fermentation, Amino acid decarboxylation. Results: n = 95 (4.5%) samples of n = 2116 samples were positive for S. haemolyticus. Most positive cultures of S. haemolyticus were from pus samples n = 40 out of n = 95. The susceptibility pattern revealed none were susceptible to penicillin and 94% susceptibility was found with Linezolid and 100% susceptibility to Nitrofurantoin. The vancomycin Minimum Inhibitory Concentration (MIC) results showed 71.57% (68/95) strains were susceptible; out of these 12 (12.63%) were showing MIC < 1 μg/mL, n = 56 isolates (58.94%) were showing MIC value less than n = 2 μg/mL, and none of them were less than MIC 0.5 μg/mL. Conclusion: In this study, variable antimicrobial resistance susceptibilities were shown by S. haemolyticus isolates. Some clinical situations may require a single strain of S. haemolyticus to be identified up to the species level with their antibiogram. Critical and timely detection of drug-resistant S. haemolyticus in hospital settings will be a helpful guide in the management and prevent further proliferation of drug resistance.