The virulence characteristics and epidemiological relationship of clinical pseudomonas aeruginosa isolates

Abstract

Pseudomonas aeruginosa is an opportunistic pathogen that can cause serious infections, especially in health care settings where host defense is impaired. In addition to resistance problem, the different virulence characteristics of these bacteria can change the course of infection and cure. In this study, it was aimed to determine antibiotic susceptibilities, epidemiological relations and virulence factors of clinical P. aeruginosa isolates. Methods: This study was performed, a total of 83 P. aeruginosa isolated from different clinical samples of Ege University Faculty of Medicine Hospital. Antibiotic susceptibilities of isolates were investigated by the VITEK 2 Compact® automated system and epidemiological relations of isolates determined via "Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR)". Phenotypic tests were performed to determine the virulence factors of the selected representatives from each clone. While the "Elastin Congo Red" method was used for the investigation of elastase activity, appropriate methods applied for Protease, DNase, Lipase, Siderophore and Twitching activities to the detect virulence properties phenotypically. The biofilm production of isolates was investigated by crystal violet method, and the quorum sensing (QS) genes thought to be related to biofilm were determined by PCR method. Results: According to results of antibiotic susceptibility test, the highest resistance was observed against imipenem (43,4%) and the lowest resistance was observed against amikacin (14,5%). Isolates were found in 19 unrelated clones according to ERIC-PZR results. Siderophore and elastase production were observed in all of the representative isolates. Protease, lipase and twitching motility were determined at 5, 14 and 15 isolates respectively, no DNAse production was detected. Nine of the 19 representative isolates produced strong biofilms, and the lasI, lasR, rhlR genes were identified in 17, 18, 13 isolates respectively and the rhlI gene was found in all strains. Conclusion: When the data were evaluated, different antibiotic resistant P. aeruginosa isolates which have different resistance profiles were detected at Ege University Faculty of Medicine Hospital. The inclusion of these resistant isolates in epidemiologically unrelated clones suggests that isolates with genotypically different properties are circulating in the clinics. Despite the many virulence factors that can contribute to pathogenesis, it is noteworthy that biofilm production is particularly prevalent in these isolates. This situation has meant that treatment becomes more difficult, as well as being able to colonize on many different surfaces in health care facilities. More extensive studies in both our country and our region could show the resistance profile of P. aeruginosa bacteria and the effects of virulence factors on the severity of infection.