Distribution of the type III effector proteins-encoding genes among nosocomial Pseudomonas aeruginosa isolates from Bulgaria

Abstract

The aim of this study was to determine the prevalence of type III effector proteins (ExoS, ExoU, ExoT and ExoY)-encoding genes among clonally unrelated nosocomial Pseudomonas aeruginosa strains and to analyze their distribution in respect to the infection site and antimicrobial resistance. Polymerase chain reaction-based detection of the genes was performed on 176 non-duplicate P. aeruginosa isolates from three University hospitals in Sofia, previously genotyped by random amplified polymorphic DNA technique. The prevalence of the studied genes was as follows: exoS-61.9%, exoU-32.4%, exoT-100%, and exoY-85.8%. The part of P. aeruginosa strains harboring either the exoS (54.0%) or the exoU (23.8%) gene was higher (P<0.001) than that of isolates containing both genes (8.5%). The gene dissemination varied according to the infection localization. The exoU gene manifested a higher spread (P<0.001) among multidrug-resistant (MDR) than in non-MDR strains (42.6 vs 18.7%). In conclusion, the P. aeruginosa type III secretion system is present in nearly all studied isolates but the individual isolates from distinct infection sites differ in their effector genotypes. The ubiquity of type III effector proteins-encoding genes among clinical isolates is consistent with an important role for this system in P. aeruginosa pathogenesis.

An investigation of type 3 secretion toxins encoding-genes of Pseudomonas aeruginosa isolates in a University Hospital in Egypt

“…12,14,21 These results indicate that exoY gene is present in the vast majority of P. aeruginosa regardless it is clinical or environmental isolates.…”

“…The absolute presence of exoT in all P. aureginosa isolates was not surprising as it was reported by several studies. 2,12,14,18 Interestingly, the presence of this gene in all examined environmental isolates suggests that there may be selection for the exoT gene in hospital environments′ P. aeruginosa isolates.…”

Contribution of an arsenal of virulence factors to pathogenesis of Pseudomonas aeruginosa infections

“…Moreover, the genes encoding some P. aeruginosa type III effector proteins are variable traits (i.e. they are found in some isolates but not in others) (Feltman et al 2001;Strateva et al 2010). To date, four effector proteins secreted by a type III secretion pathway, have been identified in P. aeruginosa: exoenzyme S (ExoS), exoenzyme U (ExoU), exoenzyme T (ExoT) and exoenzyme Y (ExoY) (Engel and Balachandran 2009).…”

Widespread dissemination of multidrug-resistant Acinetobacter baumannii producing OXA-23 carbapenemase and ArmA 16S ribosomal RNA methylase in a Bulgarian university hospital

“…3 A high clonal relatedness (72%) was proved between the ArmA-producers (n = 23) and indicated the presence of endemic clone in the AUH during 2010-2011 (Fig. 1).…”