Alina-Maria Holban, Mariana Carmen Chifiriuc, Ani Ioana Cotar, Coralia Bleotu, Alexandru Mihai Grumezescu, Otilia Banu, Veronica Lazar: Virulence markers in Pseudomonas aeruginosa isolates from hospital-acquired infections occurred in patients with underlying cardiovascular disease. Romanian Biotehnological Letters, 18, 8843-8854, 2013.
The purpose of this study was to evaluate and compare the virulence profiles of 52 recent clinical isolates of Pseudomonas aeruginosa distinctly originated from patients with hospital-acquired infections and primary cardiovascular disease. The phenotypic screening evaluated seven soluble virulence factors (haemolysins, lipase, lecithinase, DN-ase, amylase, gelatinase, caseinase), as well as the adherence ability (Cravioto adapted method) and invasion (gentamicin protection assay) of HeLa cells. Eight virulence genes (lasB, plcH, protease IV, exo S, exo T, exo A, exo U, pvdA) were screened by PCR. The statistical analysis was performed using GraphPad InStat software. The most virulent were blood culture and tracheo-bronchial isolates. Although cited as mutually exclusive, a significant number of blood culture (30%) and wound secretion (24%) isolates exhibited both exoU and exoS genes. The tracheo-bronchial secretions harbored with high positivity pvdA and lasB, while the surgical wound isolates plcH and protease IV genes. The urinary tract infections isolates exhibited less virulent phenotypes, and harbored with a high positivity rate the lasB gene. Correlating virulence patterns and infection clinical outcome could be useful for setting up efficient preventive and therapeutic procedures in hospitalized patients with positive P. aeruginosa cultures.