Virulence and resistance features of Pseudomonas aeruginosa strains isolated from chronic leg ulcers

Abstract

BackgroundThe purpose of this study was to evaluate the virulence profiles of Pseudomonas aeruginosa clinical strains recently isolated from patients hospitalized for chronic leg ulcers in the Dermatology Department of Central Military Emergency University Hospital “Carol Davila”, Bucharest, Romania.MethodsThe phenotypic screening evaluated eight soluble virulence factors (haemolysins, lecithinase, lipase, caseinase, gelatinase, amylase, DNase, aesculin hydrolysis), as well as adherence ability (Cravioto adapted method) and invasion capacity on HeLa cells (gentamicin protection assay). Seven virulence genes encoding for protease IV, 3 exoenzymes (exoS, exoT, exoU), two phospholipases plcH- haemolytic phospholipase C and plcN- non-haemolytic phospholipase C) and alginate were investigated by PCR.ResultsThe pore forming toxins and enzymes were expressed in variable proportions, the majority of the tested strains producing beta haemolysin (92.3 %), lipase (76.9 %) and lecithinase (61.5 %). The most frequent virulence genes detected in the analyzed strains were the ExoT (100 %) and AlgD (92.3 %) genes, genes codifying for phospholipases (84.6 % each of them) and for protease IV (61.5 %).ConclusionsThis study reveals that correlating virulence profiles and infection clinical outcome is very useful for setting up efficient preventive and therapeutic procedures for hospitalized patients with chronic leg ulcers and positive P. aeruginosa cultures.

Groundwater, soil and compost, as possible sources of virulent and antibiotic-resistant Pseudomonas aeruginosa

“…The rate of aprA detection (95.3%) among our environmental isolates is similar to its frequency among clinical strains isolated from ICUs. AlgD (97.7%) and plcH (86.6%) were both detected in the same values as in clinical environments (92.3-98.0% and 84.6%, respectively) (Taee et al 2014;Georgescu et al 2016). Interestingly, there was no significant correlation between the presence of plcH gene, encoding a haemolytic phospholipase C precursor, and the phenotypically determined haemolytic activity of environmental strains.…”

Pseudomonas- An Emerging Nosocomial Pathogen

“…In a study done by Georgescu M et al at Romania haemolysin was produced by 83.33% isolates and DNase produced by 16.67% isolates. 15 Control samples of our study showed 100% haemolysin production followed by gelatinase, bile esculin, deoxyribonuclease, and biofilm which accounted for 98%, 96%, 08%, 16% respectively. Virulence factors produced by control isolates were more than clinical isolates, which is consistent with study done at Sikkim Institute of Medical sciences, Gangtok, on production of slime a virulence marker in Pseudomonas aeruginosa by Prasad S, Ballal M, Shivananda P, where they concluded that slime production of the environmental strains was found to be more compared with clinical isolates which helped the organism to thrive for a longer period in the hospital environment.…”

Comparison of Antibiotic Resistance and Lipase Production in Extended Spectrum β-lactamases Producing and Non-producing Isolates of Pseudomonas aeruginosa

“…[25] Lipase production in our study was high (81%), more in ESBL producers than nonproducers which is similar to study done by Georgescu et alwhere lipase production was seen in 77% of P. aeruginosa. [26] In another study by Mohammad on P. aeruginosa isolated from burn patients, 100 % were positive for lipase production.…”