Biofilm formation in catheter-related infections by Panton-Valentine leukocidin-producing Staphylococcus aureus

The use of invasive techniques, such as intravascular catheter insertion, and the formation of biofilms in several devices by methicillin-resistant Staphylococcus aureus (MRSA) have contributed to the increased number of septic patients, morbidity and mortality. This study aimed to evaluate the virulence of strains through catheter colonization and identification of microbial biofilm, as well as pathological changes on the colonized skin. An experimental biofilm formation model utilized catheter fragments implanted subcutaneously in 25 Swiss mice. The technique consisted of inoculating a catheter fragment on the back of each animal, followed by intradermal inoculation of 50 μl of bacterial suspension at 1.0 × 10⁷ colony forming units/ml. After 96 h, catheters were removed for macroscopic analysis and evaluated through culture. Local skin fragments were also extracted for histopathology analysis. Staphylococcus aureus can adhere to catheters, colonize and form biofilms. The high amount of viable bacterial cells colonizing catheters and virulence factors can lead to severe infections of skin and adjacent tissues. [Int Microbiol 19(4): 199-207 (2016)].