title: Beta-lactamase-producing Pseudomonas aeruginosa: Phenotypic characteristics and molecular identification of virulence genes.
abstract: BACKGROUND
  Pseudomonas aeruginosa causes common infections in immunocompromised and cystic fibrosis patients. However, drug resistance capability and release of virulence factors play a key role in bacterial pathogenicity.
  
  
  METHODS
  Beta-lactamase-producing clinical isolates of P. aeruginosa were screened for biofilm formation and pigment production. Subsequently, all the isolates were subjected to the detection of six virulence genes (OprI, OprL, LasB, PlcH, ExoS, and ToxA).
  
  
  RESULTS
  Among beta-lactamase-producing isolates (n=54), about 85.18% (n=46) were biofilm producers. Pigment production was observed in 92.59% (n=50) isolates. Clinical samples were subsequently screened for detection of virulence factors. Among them, 40.74% (n=22) isolates were found to be OprI positive, while 29.62% (n=16) were OprL producers. In the case of LasB and PlcH, 24% (n=13) and 18.5% (n=10) isolates produced these virulence genes, respectively. Among the isolates, 37.03% (n=20) and 33.33% (n=18) expressed virulence factors ExoS and ToxA, respectively. Furthermore, 42.59% (n=23) isolates coproduced more than one type of virulence factors.
  
  
  CONCLUSIONS
  In the current study, pigment display, biofilm formation, and virulence genes were detected in P. aeruginosa clinical isolates. Such factors could be crucial in the development of drug resistance.
authors.affiliation: Department of Biotechnology and Genetic Engineering, Kohat University of Science & Technology, Kohat, Khyber Pakhtunkhwa, Pakistan; Department of Microbiology, Kohat University of Science & Technology, Kohat, Khyber Pakhtunkhwa, Pakistan.
authors.forename: Waheed
authors.initials: W
authors.lastname: Ullah
authors.affiliation: Department of Microbiology, Kohat University of Science & Technology, Kohat, Khyber Pakhtunkhwa, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Qasim
authors.affiliation: Department of Microbiology, Kohat University of Science & Technology, Kohat, Khyber Pakhtunkhwa, Pakistan.
authors.forename: Hazir
authors.initials: H
authors.lastname: Rahman
authors.affiliation: Department of Medical Microbiology & Parasitology, Zhejiang University, Zhejiang, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Jie
authors.affiliation: Department of Biotechnology and Genetic Engineering, Kohat University of Science & Technology, Kohat, Khyber Pakhtunkhwa, Pakistan. Electronic address: noormwazir@yahoo.com.
authors.forename: Noor
authors.initials: N
authors.lastname: Muhammad
mesh_terms: D036002:ADP Ribose Transferases / Q000235:genetics; D001427:Bacterial Toxins / Q000235:genetics; D018441:Biofilms; D005098:Exotoxins / Q000235:genetics; D006801:Humans; D010641:Phenotype; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics; D001618:beta-Lactamases / Q000096:biosynthesis*; D000097668:Pseudomonas aeruginosa Exotoxin A
chemical_list: D036002:ADP Ribose Transferases; D001427:Bacterial Toxins; D005098:Exotoxins; D037521:Virulence Factors; D001618:beta-Lactamases; D000097668:Pseudomonas aeruginosa Exotoxin A; C444820:exoenzyme S
keywords: Pseudomonas aeruginosa; beta-lactamases; virulence