Prevalence and in vitro susceptibility pattern of MRSA,VRSA, VISA isolates from various clinical samples in tertiary care hospital

ABSTRACT

Background: Staphylococcus is notorious for its ability to become resistant to antibiotics. MRSA emerged as nosocomial pathogen in the early 1960. Methicillin Resistant Staphylococcus aureus are implicated in serious infections and nosocomial infection outbreaks, thus limiting the treating options to very few agents such as vancomycin and teicoplanin. Vancomycin has been regarded as the first line drug for the treatment for MRSA but its irrational use lead to emergence of vancomycin resistance. The Aim was to determine the prevalence and resistance of MRSA ,VRSA,VISA isolates from various clinical samples in a tertiary care hospital.Material & Methods:This present prospective study was done in the Microbiology department of Government Medical College. The study was conducted for a period of one and half year i.e from January 2019 to June 2020. All the samples (pus, urine, blood, body fluids, sputum etc) were processed as per standard protocols.Results:Out of 26,471 samples, 6578(24.85%) were found to be culture positive. 1583 isolates were identified as Staphylococcus aureus. Among them 1278(80.7%) were MRSA, 21(1.3%) were VISA and 8(0.5%) were VRSA. Maximum number of MRSA isolates were obtained from orthopaedics ward (22.7%) and Intensive Care Unit and most of them were isolated from pus(45%) followed by blood (19.09%)samples. Among them highest resistance were observed against azithromycin (85.6%), followed by ciprofloxacin (63.5%) and least resistance to rifampicin and doxycycline. Majority of the VISA and VRSA strains were isolated from ICU followed by orthopaedics, surgery. Most of them were isolated from pus followed by blood and urine specimen and most were found to be multidrug resistant while they retained their sensitivity to Linezolid and Teicoplanin.Conclusions:As there is high prevalence of MRSA isolates so the treatment options are limited to vancomycin. Overuse of vancomycin can lead to emergence of VRSA strains. So the need for rational use in the infection-control practices to prevent transmission of MRSA as well as VISA strains. Strict implementation of hand hygiene, decolonization of MRSA carriers,and education of healthcare team will be quite helpful.