RESUMO
Staphylococcus aureus is an important healthcare-associated bacterium that causes a multitude of infections in humans such as superficial skin and soft tissue infections, necrotizing pneumonia, foodborne illnesses and postsurgical infections. Treatment of S. aureus infections has become more complicated due to the emergence of Methicillin-Resistant Staphylococcus aureus (MRSA), some of which are multidrug resistant. The present study aimed to characterize S. aureus isolates from a tertiary care hospital in the Rawalpindi district of Pakistan. Staphylococci were isolated from 300 clinical samples collected from January 2018 to January 2019 and S. aureus isolates were tested for antimicrobial susceptibility and analyzed using Pulsed-Field Gel Electrophoresis (PFGE), Multi-Locus Sequence Typing (MLST), staphylococcal cassette chromosome mec (SCCmec) and spa typing. Approximately 25.3% (76/300) of the clinical samples were positive for S. aureus; of those, 88.2% (67/76) were mecA+ (MRSA). In addition to the ß-lactam antibiotics, high levels of resistance were also found to the fluoroquinolones (ciprofloxacin, gatifloxacin and levofloxacin (73.7% each)). Of the 23 different spa types identified, the majority of isolates belonged to spa type t632 and t657 (9/66; 13.6% each spa type). ST772-t657 (Bengal Bay clone) was the most commonly identified clone in this study although other clones circulating around different regions of the world were also found indicating the diversity in MRSA isolates from this area of Pakistan. This study emphasizes the need to monitor MRSA in the clinical setting for improved infection control and treatment options.
RESUMO
OBJECTIVE: To isolate and characterise multidrug resistant strains of Staphylococcus aureus from healthcare workers who are at potential risk of nosocomial infections. METHODS: The observational, cross-sectional study was conducted from November 2014 to April 2015 at different hospitals of Haripur and Abbottabad, Pakistan, and comprised ward and operation theatre staff. The isolates were identified on the basis of microbiological and biochemical tests and further confirmed by polymerase chain reaction. Disc diffusion method was used for antibiotic sensitivity testing, and panton valentine leukocidin and methicillin resistance mecA genes were detected using polymerase chain reaction. RESULTS: Of 208 isolates, 108(52%) were from the ward staff and 100(48%) were from the operation theatre staff. Overall, 167(80.3%) isolates were positive for Staphylococcus aureus, and 75(36%) were methicillin-resistant Staphylococcus aureus. The number of antibiotic-resistant isolates was 75(45%) cefoxitin, 60(36%) ofloxacin, 152(91%) erythromycin, 52(31%) doxycycline, 127(76%) lincomycin, 53(32%) amoxicillin-clavulanate, 67(40%) ciprofloxacin, and 89(53%) ceftriaxone. CONCLUSIONS: A high number of hospital staff, including those working in operation theatres, were found to be carrying methicillin-resistant Staphylococcus aureus and multidrug resistant strains in their nasal passage that may be a source of infection to patients.
