Species distribution, antimicrobial resistance and biofilm production among coagulase-negative staphylococci isolated from blood and clinical specimens: A cross-sectional study from a tertiary care hospital in Sawangi (meghe), Wardha

Abstract

Background: Coagulase-negative staphylococci (CoNS) are increasingly implicated in healthcare-associated and device-related infections and are frequently associated with multidrug resistance and biofilm formation. AimsandObjectives: TodeterminethespeciesdistributionofCoNSisolatedfromclinicalspecimensandtoassessantimicrobialresistancepatterns, methicillin resistance, and biofilm production. Materials and Methods: A hospital-based cross-sectional study was conducted in the Department of Microbiology of a tertiary care hospital from July 2022 to December 2023. CoNS isolates were identified and speciated by standard phenotypic methods. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion as per CLSI 2022. Methicillin resistance was assessed using the cefoxitin disc. Biofilm production was detected by tissue culture plate (TCP) and standard tube (ST) methods. Results: Of 12,188 specimens processed, 130 CoNS isolates were obtained. Most isolates were from blood 115 (88.5%), followed by urine 8 (6.2%), CSF 3 (2.3%), pleural fluid 3 (2.3%) and BAL 1 (0.8%), ICU areas contributed 54 (41.5%) isolates. Predominant species were S. epidermidis 54 (41.5%) and S. haemolyticus 39 (30.0%). Resistance was highest to azithromycin 110 (84.6%), penicillin 107 (82.3%) and erythromycin 102 (78.5%), cefoxitin resistance was 91 (70.0%). Vancomycin resistance was 4 (3.1%), while all isolates were susceptible to linezolid and tetracycline. Biofilm production was detected in 81 (62.3%) isolates by TCP and 70 (53.8%) by ST. Conclusion: CoNS in this setting show high macrolide/ β -lactam resistance with substantial methicillin resistance and frequent biofilm production. The predominance of blood isolates and substantial ICU burden suggest potential clinical relevance, underscoring the need for routine speciation, careful clinical correlation, AST-guided therapy, stringent infection control and antimicrobial stewardship.