Screening of Molecular Virulence Markers in Staphylococcus aureus and Pseudomonas aeruginosa Strains Isolated from Clinical Infections

Abstract

Staphylococcus (S.) aureus and Pseudomonas (Ps.) aeruginosa are two of the most frequently opportunistic pathogens isolated in nosocomial infections, responsible for severe infections in immunocompromised hosts. The frequent emergence of antibiotic-resistant S. aureus and Ps. aeruginosa strains has determined the development of new strategies in order to elucidate the different mechanisms used by these bacteria at different stages of the infectious process, providing the scientists with new procedures for preventing, or at least improving, the control of S. aureus and Ps. aeruginosa infections. The purpose of this study was to characterize the molecular markers of virulence in S. aureus and Ps. aeruginosa strains isolated from different clinical specimens. We used multiplex and uniplex PCR assays to detect the genes encoding different cell-wall associated and extracellular virulence factors, in order to evaluate potential associations between the presence of putative virulence genes and the outcome of infections caused by these bacteria. Our results demonstrate that all the studied S. aureus and Ps. aeruginosa strains synthesize the majority of the investigated virulence determinants, probably responsible for different types of infections.

Crataeva nurvala nanoparticles inhibit virulence factors and biofilm formation in clinical isolates of Pseudomonas aeruginosa

“…The emergence of multiple drug resistance in pathogenic microorganisms has become a serious threat worldwide, and this trend has aroused due to excessive use of antibiotics. Pseudomonas aeruginosa is a gram‐negative opportunistic pathogen and attacks individuals suffering from cystic fibrosis, cancer, AIDS, or patients with indwelling medical devices or burns P. aeruginosa produces various kinds of infections assisted by the production of extracellular virulence factors such as pyocyanin, proteases, and haemolysin . These virulence factors including toxins and adhesion molecules play an active role in damaging the host tissues .…”

“…assisted by the production of extracellular virulence factors such as pyocyanin, proteases, and haemolysin [5,6]. These virulence factors including toxins and adhesion molecules play an active role in damaging the host tissues [7,8].…”

Investigating prevalence of pathogenic genes (ETA and TSST-1) in Staphylococcus aureus isolated from different wards of the hospitals by PCR method

“…As major virulence factors in Staphylococcus aureus, TSST-1and ETA are pyrogenic toxins that have been implicated in host colonization, invasion of damaged skin and mucus and evasion of host defense mechanisms. [15], [16] The coordinated expression of S. aureus secreted and cell wall-associated virulence factor is regulated by a complex network, including the quorumsensing (QS) system agr and the well characterized virulence gene regulators [17]. In comparison with other methods, PCR is a proper, sensitive and cheap method for recognizing toxigenic genes [14] .…”

Optimized Anti-pathogenic Agents Based on Core/Shell Nanostructures and 2-((4-Ethylphenoxy)ethyl)-N-(substituted-phenylcarbamothioyl)-benzamides

“…The P. aeruginosa strains isolated in Romania from invasive infections showed high resistance rates to cephtazidime (52.2%) and to carbapenems (60.9%) [24]. …”

“…Bacteria from biofilm are resistant to disinfectants, antibiotics and the action of host immune defenses [24]. …”