TY - JOUR T1 - Biofilm production by clinical isolates of Pseudomonas aeruginosa and structural changes in LasR protein of isolates non biofilm-producing JO - The Brazilian Journal of Infectious Diseases T2 - AU - Lima,Jailton Lobo da Costa AU - Alves,Lilian Rodrigues AU - Jacomé,Paula Regina Luna de Araújo AU - Bezerra Neto,João Pacífico AU - Maciel,Maria Amélia Vieira AU - Morais,Marcia Maria Camargo de SN - 14138670 M3 - 10.1016/j.bjid.2018.03.003 DO - 10.1016/j.bjid.2018.03.003 UR - https://www.bjid.org.br/en-biofilm-production-by-clinical-isolates-articulo-S1413867018300758 AB - IntroductionBiofilm production is an important mechanism for the survival of Pseudomonas aeruginosa and its relationship with antimicrobial resistance represents a challenge for patient therapeutics. P. aeruginosa is an opportunistic pathogen frequently associated to nosocomial infections, especially in imunocompromised hosts. ObjectivesAnalyze the phenotypic biofilm production in P. aeruginosa isolates, describe clonal profiles, and analyze quorum sensing (QS) genes and the occurrence of mutations in the LasR protein of non-biofilm producing isolates. MethodsIsolates were tested for biofilm production by measuring cells adherence to the microtiter plates. Clonal profile analysis was carried out through ERIC-PCR, QS genes were by specific PCR. ResultsThe results showed that 77.5% of the isolates were considered biofilm producers. The results of genotyping showed 38 distinct genetic profiles. As for the occurrence of the genes, 100% of the isolates presented the lasR, rhlI and rhlR genes, and 97.5%, presented the lasI gene. In this study nine isolates were not biofilm producers. However, all presented the QS genes. Amplicons related to genes were sequenced in three of the nine non-biofilm-producing isolates (all presenting different genetic similarity profile) and aligned to the sequences of those genes in P. aeruginosa strain PAO1 (standard biofilm-producing strain). Alignment analysis showed an insertion of three nucleotides (T, C and G) causing the addition of an amino acid valine in the sequence of the LasR protein, in position 53. ConclusionThe modeling of the resulting LasR protein showed a conformational change in its structure, suggesting that this might be the reason why these isolates are unable to produce biofilm. ER -