COMPARATIVE STUDY OF STAPHYLOCOCCUS AUREUS ISOLATES IN PUS AND NASAL SWABS AMONG LAHORE PATIENTS

Abstract

Staphylococcus aureus predominately found in nasal and pus samples is one of the major causes of skin infections and invasive diseases like endocarditis, pneumonia, and osteomyelitis. The current study was performed over the 3 month period, from April 2022 to June 2022. A total of 368 participants’ nasal and pus swab specimens were included in this study and were collected from the different hospitals in Lahore. The objective of the study was to discern the relative prevalence of Staphylococcus aureus isolates in Pus and Nasal Swabs among Patients in Lahore. All the collected samples were cultured in sterile conditions on Blood agar, Chocolate agar, MacConkey agar, and Mannitol salt agar according to the standard laboratory guidelines. S. aureus culture plates were identified based on the colonial morphology after 48hrs. Furthermore, isolated bacteria were characterized based on Gram stain, and differential biochemical analyses like the Coagulase test, Oxidase test, Catalase test, Triple sugar iron, Urease test, Indole test, Motility agar test that was performed to reconfirm S. aureus presence in the given pus and nasal specimens. The modified Kirby Bauer disc diffusion method was employed for antimicrobial susceptibility testing and Zone sizes were interpreted according to the Clinical and Laboratory Standard Institute guidelines (2020). From a total of 368 bacterial samples, 283 were pus swabs and 85 were nasal swabs, whereas the most frequently isolated organism was gram-positive Staphylococcus aureus which accounts for 90% (330) of the total samples. Our results showed a 90 % MRSA prevalence rate in Lahore and in our study oxacillin represents high resistance against MRSA in nasal samples, whereas, clindamycin represents high resistance in pus samples respectively. The reason for this increased prevalence of MRSA is due to the irrational use of antibiotics without prior cultural reports, the absence of antimicrobial situation programs in hospitals, and the failure to look at the infection management practices which may be some of the highlighted reasons for this drawback in the hospital and clinical setup.