D-117. Multirresistance and Adhesion Properties among Staphylococcus epidermidis Isolated from Blood Cultures in a Public Hospital, Brazil

M. F. L. Barros¹, J. C. O. Tortora¹, L. A. Teixeira¹, J. A. A. Pereira², C. Matheus-Guimarães¹, D. P. Alves¹, R. S. Sant'Anna¹, A. M. F. Cerqueira¹;
¹Univ. Federal Fluminense, Niterói, BRAZIL, ²Univ. do Estado do Rio de Janeiro, Rio de Janeiro, BRAZIL.

Background: Coagulase-negative staphylococci, in particular Staphylococcus epidermidis have emerged as major nosocomial pathogens associated with infections of implanted medical devices. Despite being part of normal human skin microbiota, their clinical significance as casual infectious agents in patients with indwelling medical devices such as central and peripheral venous catheters, valvular prosthesis and other infections involving biofilm formation on implanted biomaterial have increased in the last decades. An extracellular polysaccharide adhesin represents a key virulence determinant in S. epidermidis and is required for biofilm formation. Production of this adhesin is encoded by icaAD operon. The oxacillin resistance, encoded by mecA, is an important characteristic of this bacterial group. Objective: Search the profile of antimicrobials resistance, and the presence of icaAD and mecA genes in sixteen strains of S. epidermidis isolated from blood cultures of patients in a Public Hospital in Rio de Janeiro, Brazil. Methods: Species identification was confirmed by manitol fermentation, coagulase and urease production, polymyxin B and novobiocin susceptibility, and Voges-Proskauer test. The resistance profile against thirteen antimicrobials was evaluated by disk diffusion method. icaAD and mecA genes were searched using PCR assays. Results: The majority of strains were resistant to penicillin (94%) and additionally to oxacilin and ciprofloxacin (63%). Moreover, thirteen strains (81%) were multidrug resistant and one of them was susceptible only to rifampicin and vancomicyn. All oxacilin resistant strains were also positive to mecA. The icaAD gene was detected in five strains all but one was also positive to mecA. Conclusion: Although all the studied strains were isolated from blood culture of patients with infectious disease signals a low occurrence of icaAD gene was detected that suggests the presence of additional adhesion properties. The large resistance profile of the strains reinforces the importance of strict control measures to prevent nosocomial infections.