Prevalence and antibacterial resistance patterns of uropathogenic staphylococci in Casablanca, Morocco

Introduction: The purpose of this research is to evaluate the resistance profile of uropathogenic staphylococci bacteria in Casablanca, Morocco.

Methodology: In this retrospective cross-sectional research carried out from January 2017 to December 2020, isolation and identification were carried out according to the usual techniques in medical microbiology. Staphylococcus aureus isolates were confirmed by polymerase chain reaction (PCR) amplification of the nuc gene, and the antibiogram was performed according to the guidelines of the Antibiogram Committee of the French Society of Microbiology (CA-SFM 2021). The susceptibility of uropathogenic staphylococci to vancomycin was determined with broth microdilution following the recommendations of the Clinical and Laboratory Standards Institute. The mecA gene was tested on phenotypically cefoxitin-resistant S. aureus isolates by PCR.

Results: The prevalence of urinary tract infections (UTIs) was 18% (772/4374). UTIs were more common in females (n = 483, 63%) than males (n = 289, 37%). Among the Gram-positive bacteria isolated (198, 25.65%), the prevalence of staphylococci was (130/198, 65.66%). Among staphylococcal species identified, coagulase-negative staphylococci (CoNS) were more prevalent (112/130, 86.15%), and Staphylococcus saprophyticus was the most frequently isolated CoNS (46/112, 41.07%). Additionally, there were several S. aureus strains (18/130, 13.85%). Forty-four percent of S. aureus isolates (n = 8) were resistant to cefoxitin and also harboured the mecA gene. All S. aureus isolates were susceptible to linezolid, cotrimoxazole and vancomycin.

Conclusions: The prevalence and antibacterial resistance patterns of uropathogenic staphylococci in this study, with a high percentage of methicillin resistance, require careful consideration of antimicrobial therapy for staphylococcal UTIs.