Association between Biofilm Formation and Susceptibility to Antibiotics in Staphylococcus Lentus Isolated from Urinary Catheterized Patients

Staphylococcus lentus (S. lentus) is a coagulase negative gram positive cocci recognized as opportunistic pathogens and rarely forming biofilm; it has many virulence factors, but recently caused nosocomial and community infections. Biofilm formation of Staphylococcus lentus may be associated with the ability to resist antibiotics which leads to increase in mortality rate due to the difficulty in eradicate infections. To evaluate the biofilm forming capacity of Staphylococcus lentus and its susceptibility to antibiotics, phenotypic and genotypic assays were used. Among 28 biofilm bacteria, Staphylococcus lentus was isolated and identified from urine catheterized patients who were hospitalized in different departments of four Iraqi hospitals (Al-Diwaniyah Teaching, Al-Hilla Teaching, Al Qassim and Al Hashimiyah Hospitals). Staphylococcus lentus was examined for detection of biofilm formation by detecting icaA gene, the intercellular adhesion gene which expressed adhesion factor to form biofilm in staphylococci by using polymerase chain reaction (PCR) method and tested for antimicrobial susceptibility by disc diffusion method and VITEK2 system according to guidelines of the Clinical & Laboratory Standards Institute (CLSI).Three isolates of Staphylococcus lentus revealed the ability to form biofilm phenotypically which contained icaA gene with 100% antibiotics resistance to penicillin, carbenicillin, gentamicin, tobramycin, oxacillin, vancomycin, clindamycin, ciprofloxacin, and 0% antibiotics resistance to azithromycin. icaA genes are present in Staphylococcus lentus and responsible for biofilm formation which is considered as the indicator; biofilm formation is a strong cause of multidrug resistance in bacteria.