Rafik Aniba
Sultan Moulay Slimane University, Beni Mellal, Morocco
Title: Phenotypic and genotypic characterization of antimicrobial susceptibility and biofilm formation by uropathogenic Staphylococcus haemolyticus
Biography
Biography: Rafik Aniba
Abstract
Introduction: This study aimed to assess the correlation between antibiotic resistance and biofilm formation capacity in Staphylococcus haemolyticus strains isolated from patients with urinary tract infections (UTIs).
Methods: Antibiotic susceptibility testing was conducted using the disc diffusion and liquid microdilution methods. The blaZ and mecA genes were investigated in all penicillin- and cefoxitin-resistant S. haemolyticus isolates by PCR. Biofilm formation was investigated using the Congo red agar and tissue culture plate methods. All S. haemolyticus isolates were screened for genes encoding adhesion and biofilm formation (atlE, embP, eno, aap, fnb AB, clfA, and bap) and intercellular adhesin (icaADB and icaR).
Results: Among the 21 S. haemolyticus isolates, 85.71% were multidrug-resistant (MDR) and methicillin-resistant (MRSH). 95% of the strains were biofilm producers, including 43% of moderate biofilm producers and 5% of strong biofilm producers. A significant correlation was observed between the MRSH and MSSH isolates in terms of biofilm production. All strains were sensitive to linezolid and 22.2 % exhibited an inducible clindamycin resistance phenotype.
The effect of antibiotics on the inhibition of biofilm formation is controversial; vancomycin, gentamicin, and ciprofloxacin subinhibitory antibiotic concentrations promote biofilm formation in most S. haemolyticus isolates.
The eno gene was present in 76.2% of the S. haemolyticus strains, followed by aap (42.8%), icaD (42.8%), and atlE (23.8%). Meanwhile, 9.5 % of the isolates carried embP and icaA genes.
Conclusion: This study revealed a significant association between biofilm formation by uropathogenic S. haemolyticus and antibiotic resistance, highlighting a noteworthy public health concern.