ADHESION CAPACITY TO HOSPITAL MATERIALS BY BACTERIAL STRAINS

INTRODUCTION:. The use of probes, catheters, needles and endotracheal tubes is a routine practice in the nosocomial environment, and while it conditions survival, it confers a certain exposure to the action of microorganisms. Some bacterial species are easily disseminated in the environment and have the ability to adhere to inanimate surfaces. This process is a major concern in clinical care, given its obvious influence on patient morbidity and mortality. The aim of this study was to assess the ability of some bacterial strains of clinical origin to adhere to hospital materials. METHODS: This is a descriptive experimental study with a quantitative approach. The following clinical bacterial strains were used to show their ability to adhere: P.aeruginosa, S. aureus, S. putrefaciens and B. pseudomallei (CEP 394894). The bacterial suspensions were prepared in 0.9% saline and standardized according to the 0.5 turbidity of the MacFarland scale. Latex, silicone, leather and fabric bladder probes were used to produce the specimens, which were 0.5 mm in diameter. Each specimen was kept separately in tubes containing 5 mL of BHI broth (previously sterilized), where 0.1 mL of the bacterial suspension was added and incubated in an oven at 37ºC for different times (1, 3, 6, 12h).Afterwards, the specimens were washed and transferred to tubes with 5 mL of saline solution to be shaken in a Vortex. Then 0.1ml of each shaken suspension was removed and sown on plates with Mueller Hinton Agar and incubated in a bacteriological oven at 37ºC/24h to count the Colony Forming Units (CFU). RESULTS: All the strains evaluated had the potential to adhere to the different materials. It was also confirmed that time influences the increased colonization of these bacteria, as the number of colonies increased after each time.  S. aureus, P. aeruoginosa and B. pseudomallei obtained the following CFU on the tissue after 12 hours of incubation: 2,523, 4,754, 4,560. This was the material most susceptible to the expression of this virulence factor.  CONCLUSION: Bacterial strains of clinical origin have the potential to adhere to different materials. The type of material, exposure time and bacterial species are all factors that interfere with this virulence.