DefinePK

Abstract

Staphylococcus aureus is a major cause of infections such as skin, bone-joint, pneumonia, septicemia etc. Its resistance to antibiotics is a growing concern. The notable resistant phenotype Methicillin resistant Staphylococcus aureus (MRSA) is a persistent pathogen in nosocomial as well as community infections. In Pakistan, MRSA cases have been steadily increasing; however, there is a significant lack of up-to-date regional data on its antibiotic resistance patterns; information crucial for developing effective treatment strategies and public health policies. 2,000 clinical samples were processed for S. aureus isolation using standard microbiological methods. Of these, 360 isolates (18%) were confirmed as S. aureus, and 82% as other pathogens. The overall recovery of MRSA was 7.7% (n=154). The highest recovery rate of S. aureus was from pus samples (30%), followed by blood (9%) and urine (5%). MRSA was identified in 43% of isolates using cefoxitin resistance, with the highest frequency in urine samples (57%). Gender-based analysis showed more MRSA in male urine samples (71%). Antibiotic susceptibility testing revealed high resistance to erythromycin (74%), cefepime (67%), and norfloxacin (66%). MRSA isolates exhibited greater resistance overall, especially to cefepime (79%), erythromycin (76%), and fluoroquinolones (68%). Notably, urinary MRSA strains showed 100% resistance to multiple antibiotics. Vancomycin resistance was more prevalent among female MRSA cases. To evaluate differences between MRSA and MSSA resistance patterns, percentage differences, odds ratios, and chi-square tests were applied. Statistically significant differences (p-value < 0.00001) were observed for all antibiotics except linezolid and norfloxacin, indicating a strong association of resistance with MRSA strains.
Keywords: Antibiotic Resistance; MRSA; S. aureus
http://dx.doi.org/10.19045/bspab.2025.140087