Catheter-related infections caused byPseudomonas aeruginosa: virulence factors involved and their relationships

Abstract

The nosocomial pathogen Pseudomonas aeruginosa is equipped with a large arsenal of cell-associated and secreted virulence factors which enhance its invasive potential. The complex relationships among virulence determinants have hitherto not been fully elucidated. In the present study, 175 catheter-related isolates were observed for the presence of selected virulence factors, namely extracellular enzymes and siderophore production, biofilm formation, resistance to antibiotics, and motility. A high percentage of the strains produced most of the tested virulence factors. A positive correlation was identified between the production of several exoproducts, and also between the formation of both types of biofilm. An opposite trend was observed between the two types of biofilm and the production of siderophores. Whereas the relationship between the submerged biofilm production (i.e. the biofilm formed on the solid surface below the water level) and the siderophore secretion was negative, the production of air-liquid interface (A-L) biofilm (i.e. the biofilm floating on the surface of the cultivation medium) and the siderophore secretion were positively correlated. All correlations were statistically significant at the level P = 0.05 with the correlation coefficient γ ≥ 0.50. Our results suggest that: (1) the co-production of the lytic enzymes and siderophores can play an important role in the pathogenesis of the catheter-related infections and should be taken into account when the virulence potential is assessed; (2) biofilm-positive strains are capable of forming both submerged and non-attached A-L biofilms; and (3) the different micro-environment in the submerged biofilm and A-L biofilm layers have opposite consequences for the production of other virulence factors.

An integrated genomic regulatory network of virulence-related transcriptional factors in Pseudomonas aeruginosa

“…P. aeruginosa harbours multiple key determinants of virulence, including quorum sensing (QS), Type III (T3SS) and Type VI secretion systems (T6SS), flagella and type IV pili. Taken together, these determinants comprise a highly complex and well-ordered virulence system 4–8 .…”

Diarylheptanoids from Alnus viridis ssp. viridis and Alnus glutinosa: Modulation of Quorum Sensing Activity in Pseudomonas aeruginosa

“…It is a primary cause in infections associated with cystic fibrosis (CF), burn wounds and the use of catheters and other medical devices, and a major cause of nosocomial infections [34]. Its biofilm forming ability leads to an increased tolerance to antibiotics and the persistence of chronic infections [35,36]. P. aeruginosa is often expanded by food, so natural agents suppressing their communication and influencing persistence and virulence are highly sought after.…”

A Recombinant Snake Cathelicidin Derivative Peptide: Antibiofilm Properties and Expression in Escherichia coli

“…These pathogens are commonly associated with nosocomial and hospital-acquired infections, especially in the ICU and burn sites. [23,60,61]. The strategy of applying AMPs as an anti-biofilm has been considered, which may represent promising approaches to control biofilms [46].…”