title: Difference of Type 3 secretion system (T3SS) effector gene genotypes (exoU and exoS) and its implication to antibiotics resistances in isolates of Pseudomonas aeruginosa from chronic otitis media.
abstract: OBJECTIVE
  Type 3 secretion system (T3SS) is the most important virulence factor in Pseudomonas aeruginosa infection. Of the various T3SS effector genes, exoS and exoU showed mutually exclusive distributions, and these two genes showed varied virulence. In many pseudomonal infections, the distribution of these genes showed different pattern and it influenced severity of infection. This study was aimed to evaluate differences of virulence factors and antibiotics resistance between chronic otitis media and other body infection caused by P. aeruginosa.
  
  
  METHODS
  To estimate the prevalence of effector genes of T3SS, especially the distributions of exoS and exoU genes and their association with antibiotic resistance in COM, we compared the prevalence of T3SS genes in isolates from COM with those from lower respiratory infection and bacteremia. Other virulence genes, including groEL, pilA, ndvB, lasB, rhlI, and apr, were also studied to evaluate prevalence. These isolates were tested for antibiotic susceptibility, and we examined the association between antibiotic susceptibility and the prevalence of T3SS effector genes.
  
  
  RESULTS
  The COM group showed a significantly higher exoU-positive rate than the control group (70.6% vs. 6.7%; P<0.01). Furthermore, COM patients with exoU showed significant antibiotic resistance to ciprofloxacin and tobramycin (P=0.035), whereas there was no significant difference in the control group.
  
  
  CONCLUSIONS
  The high incidence of exoU-positive P. aeruginosa and ciprofloxacin resistance can explain the chronicity and intractability of infection in COM. Elucidation of this pathogenicity will facilitate the development of new treatment options for COM patients.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul Metropolitan Government-Seoul National University, Seoul, Republic of Korea.
authors.forename: Min-Hyun
authors.initials: MH
authors.lastname: Park
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea. Electronic address: sossi81@hanmail.net.
authors.forename: So Young
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Clinical Laboratory Medicine, Boramae Medical Center, Seoul Metropolitan Government-Seoul National University, Seoul, Republic of Korea.
authors.forename: Eun Yun
authors.initials: EY
authors.lastname: Roh
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Boramae Medical Center, Seoul Metropolitan Government-Seoul National University, Seoul, Republic of Korea.
authors.forename: Ho Sun
authors.initials: HS
authors.lastname: Lee
mesh_terms: D036002:ADP Ribose Transferases / Q000235:genetics*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics*; D018834:Chaperonin 60 / Q000235:genetics; D002908:Chronic Disease; D002939:Ciprofloxacin / Q000627:therapeutic use; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005260:Female; D020690:GTPase-Activating Proteins / Q000235:genetics; D005838:Genotype; D005964:Glucosyltransferases / Q000235:genetics; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010033:Otitis Media / Q000188:drug therapy / Q000382:microbiology*; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014031:Tobramycin / Q000627:therapeutic use; D000069296:Type III Secretion Systems / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D018834:Chaperonin 60; C477521:ExoT protein, Pseudomonas aeruginosa; D020690:GTPase-Activating Proteins; D000069296:Type III Secretion Systems; D037521:Virulence Factors; C111749:pseudomonas exoprotein A protein, Pseudomonas aeruginosa; D002939:Ciprofloxacin; C111504:ExoY protein, bacteria; D005964:Glucosyltransferases; D036002:ADP Ribose Transferases; C444820:exoenzyme S; D014031:Tobramycin
keywords: Antibiotics resistance; Otitis media; Pseudomonas; Type 3 secretion system; Virulence factors; exoU