Estudo da formação de biofilmes por pseudomonas aeruginosa

Abstract

The formation of biofilm by P. aeruginosa occurs through the production of specific polysaccharides, which increase its pathogenicity and resistance to antibiotics, among other factors, of inhibition of penetration. One of the main characteristics of the microbial biofilm is its high resistance to antimicrobial agents and the host defense system, being an average of 10 to 100 times greater in relation to planktonic life forms. This feature of low antimicrobial susceptibility makes it difficult to eradicate these infections caused by biofilm-forming bacteria. This work aims to study the kinetics of biofilm formation by Pseudomonas aeruginosa in polystyrene microplates in different media and time intervals, with the quantification of the total biomass formed. Were used Pseudomonas aeruginosa isolates and standard American Type Culture Collection strains (ATCC 9027, ATCC 27853) from the collection of the Laboratory of Microbiology of the State University of Goiás (UEG - CCET) and a clinical isolate of commercial chicken liver, collected from slaughterhouses and refrigerators of Goiás State, under state inspection system, using the methodology described by Stepanovic et al. (2004) with some modifications. The results obtained for the studied strains showed better conditions of biofilm formation in more nutritious broth (TSB), in incubation time of 24 h, except for the strain of clinical isolate of commercial chicken liver that presented similar levels of biofilm formation for the incubation times of 24 and 48 h, differing only when the TSB broth of 48 h was used in comparison with the AP of 48 h of incubation, thus presenting a slower development rate in relation to the other strains studied. Another aspect observed is that all the readings obtained for the standard strains with 24h incubation were superior to those obtained with 48h. This shows the influence of the nutritional composition of the medium and the capacity of biofilm formation, as well as the performance of the incubation time in relation to the biofilm intensity formed, and the variation of the adhesion factors according to each bacterial lineage.