Phylogeny of hospital acquired MRSA, and its comparative phenotypic clinico-epidemiology with vancomycin resistant S. aureus (VRSA). (December 2020) - Rehman, Tayyab ur
Abstract: Staphylococcus aureus is emerging as complicated pathogen because of its wide-ranging origin, multiple variants, and compromised antibiotic susceptibilities. Current study was planned to find lineage of hospital acquired methicillin resistant Staphylococcus aureus (HA-MRSA), and its comparative phenotypic clinico-epidemiology with vancomycin resistant S. aureus (VRSA). A total of (n = 200) samples were aseptically collected from wound, nose, and cerebrospinal fluid of patients from metropolitan and rural background hospitals along with on spot filling in of questionnaire. Phylogenetic analysis of HA-MRSA was identified by targeting mecA gene in S. aureus . At optimal tree branch length of 1.91 and evolutionary distance 0.1, high level sequence similarity (97%–99%) was observed with different strains of S. aureus isolated from both human and animal. Non-descriptive statistics at 5% probability found 61% S. aureus, while 43.44% of them were HA-MRSA, 92.62% VRSA, and 42.62% were both MRSA and VRSA. Among assumed risk factors, use of antibiotics, venous catheterization, chronic disease, pre-hospital visits, and ICU admitted patients showed significant association ( p <0.05) with pathogen. HA-MRSA was 37.50%, 80%, and 37.50% sensitive to chloramphenicol, gentamicin, and oxacillin, respectively. While <50% of VRSA were sensitive against oxacillin, enoxacin, and chloramphenicol. A significant difference ( p <0.05) of percentage responses of MRSA and VRSA at resistant, intermediate, and sensitive cadre against all antibiotics except chloramphenicol was obvious in this study. The Current study concluded higher prevalence of MRSA & VRSA, significant association of risk factors, limiting antibiotic susceptibility profile, and genetic transfer at animal-human interface which suggests further studies cum preventive strategies to be planned. Highlights: S. aureus is emerging as complicated pathogen due to its wide-ranging origin. High prevalence of MRSA, VRSA in hospital patients on base of mecA gene. Trimethoprim-sulphamethoxazole, oxytetracycline, gentamicin showed higher efficacacy. Clade (3650727_4_P; S. aureus _P10_Human) shared a common ancestor from same geographical location.