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

Abstract

Objective: Pseudomonas aeruginosa uses type 3 secretion system (T3SS) to directly inject four toxins into host cells. The aim of the study was to determine the prevalence of the toxins-encoding genes among P. aeruginosa isolates collected from nosocomial infections and environmental sources.Methods: Clonal relatedness of the studied P. aeruginosa isolates (n=85) was studied by RAPD typing. Multiplex PCR was performed on the 85 P. aeruginosa isolates (68 nosocomial isolates obtained from hospitalized patients present in different wards and departments, and 17 environmental isolates including 2 isolates from health-care worker hands from ICU) to detect the secretion toxins-encoding genes.Results: RAPD fingerprinting demonstrated that most strains were of distinct genotypes and determined the presence of 54 RAPD patterns. The prevalence of the genes among all isolates was as follows; exoT-100%, exoS-40%, exoY-83.5% and exoU-62.4%. No significant differences in the prevalence of these genes were observed between nosocomial and environmental isolates or between isolates cultured from different sites of infection. The part of P. aeruginosa strains harboring either exoS (37.6%) or exoU (60%) gene was significantly higher (P<0.001) than that contained both genes (2.4%). Conclusion:ExoT was present in all isolates and exoS, exoY and exoU are variable traits with exoU gene was the third in prevalence after exoT and exoY. No significant differences in exoS, exoY and exoU prevalence were observed between nosocomial and environmental isolates or between isolates from different sites of infection. ExoS and exoU genes were mutually exclusive that almost all isolates contain either exoS without exoU or exoU without exoS. Yöntemler: Çalışılan P. aeruginosa izolatlarının klonal yakınlığı RAPD tiplendirme metodu ile bakılmıştır. Sekretuar toksin kodlayan genleri saptamak için 85 P. aeruginosa izolatında (farklı klinik ve bölümlerde yatan hastalardan izole edilen 68 hastane kaynaklı izolatı ve ikisi yoğun bakım ünitesindeki sağlık çalışanının ellerinden izole edilen 17 çevresel izolat) multiplex PCR çalışıldı.Bulgular: RAPD fingerprint analizi ile varlığı tespit edilen 54 RAPD paterninin varlığı suşların çoğunun uzak genotiplere sahip olduğunu gösterdi. Tüm izolatlarda saptanan genlerin prevalansı sırasıyla exoT (% 100), exoS (% 40), exoY (% 83,5) ve exoU (% 62,4) şeklindeydi. Farklı enfeksiyon bölgelerinden üretilen izolatlar arasında yada hastane ve çevresel kaynaklardan elde edilen izolatlar arasında bu genlerin prevalansı açısından anlamlı bir fark yoktu. P. aeruginosa suşla-rından exoS (% 37,6) veya exoU (% 60) genlerinden birini taşıyanlar her iki geni taşıyanlardan (% 2,4) anlamlı olarak daha fazlaydı (p<0.001). Sonuç:ExoT tüm izolatlarda bulunurken exoS, exoY ve exoU genlerinin varlığı değişkenlik gösteriyordu. ExoU geni exoT ve exoY geninden sonra üçüncü sıklıkta görülmekteydi. exoS, ExoY ve exoU görülme prevalansı hastane kaynaklı ve çev-re kaynaklı suşlar arasında veya değişik bölge veya enfeksiyonlar arasında an...

Occurrence, virulence, carbapenem resistance, susceptibility to disinfectants and public health hazard of Pseudomonas aeruginosa isolated from animals, humans and environment in intensive farms

“…The predominance of exo T followed by exo Y and exo S genes in human P . aeruginosa isolates in this study agreed with previous reports (Gawish et al, 2013; Khodayary et al, 2019). The frequency of tox A gene in our tested P .…”

“…The predominance of exoT followed by exoY and exoS genes in human P. aeruginosa isolates in this study agreed with previous reports (Gawish et al, 2013;Khodayary et al, 2019). The frequency of toxA gene in our tested P. aeruginosa isolates from cattle, livestock drinking water and farm workers agreed with Elshafiee et al (2019).…”

Virulence genome analysis of Pseudomonas aeruginosa VRFPA10 recovered from patient with scleritis

“…Blast analysis against various available virulence databases from NCBI unveiled the presence of Type 3 Secretion system (T3SS) cytotoxin encoding exoenzymes such as Exo-U, Exo-T, Exo-Y gene, Elastase B and ExotoxinA encoding genes among VRFPA10 genome [17] . These Exotoxin A and Elastase B are known to have an effect on ocular tissues, which may may have facilitated to adjacent episcleral invasion leading to scleritis condition.…”

Draft genome sequence of bla_Veb-1, bla_oxa-10producing multi-drug resistant (MDR) <italic>Pseudomonas aeruginosa</italic>strain VRFPA09 recovered from bloodstream infection

“…In addition, a novel integron designated as In1147 comprised of bla Veb-1 , bla OXA-10, dfrB2, aacA7, aadA1genes in array of gene cassettes which confers broad spectrum resistance to third generation cephalosporins, aminoglycosides and meropenem drug was detected ( Yin et al , 2008 ). Analysis using Blast revealed the presence of Type 3 Secretion system (T3SS) cytotoxin encoding exoenzyme U gene ( Gawish et al , 2013 ). However, further study on VRFPA09 genome is required for detecting multifactorial resistance genes and its molecular mechanism of resistance.…”