title: Distribution of genes encoding virulence factors ompB2, ompCD, ompE, β-lactamase and serotype in pathogenic and colonizing strains of Moraxella catarrhalis.
abstract: OBJECTIVE
  A total of 115 Moraxella catarrhalis isolates from patients with lower respiratory tract and otorhinolaryngeal infections, as well as healthy carriers, were collected to study the prevalence of outer membrane virulence and resistance encoding genes and lipooligosaccharide (LOS) serotypes.
  
  
  METHODS
  PCR technique was used to determine the presence of genes ompB2 (encoding uptake of vital iron), ompCD and ompE (for adhesion, complement resistance and transporter proteins), bro1 and bro2 (for β-lactamases). Serotyping was carried out by monoclonal antibodies (MAb) against LOS serotypes A, B and C.
  
  
  RESULTS
  The frequency of genes determining virulence factors were ompE 82.61%, ompCD 70.43%, ompB2 43.48%, and bro 98.26%. Dissemination of virulence genes varied according to the type of infections and carrier state.
  
  
  CONCLUSIONS
  The present study revealed the presence of a greater number of virulence factors in isolates from patients compared to that in strains from healthy individuals. In the strains of patients with bronchopulmonary infections, a combination of ompB2-ompCD-ompE genes was predominant. In patients suffering from otorhinolaryngeal infections, isolates with combination ompCD-ompE prevailed. Isolates from the control group revealed single ompCD or ompE genes or none of the virulence genes tested. The greatest proportion (91.30%) of β-lactamases was encoded from bro1 genes. Serotype A was the most frequent (70.43%) serotype. No correlation was found between the strain serotype and presence of the virulence and β-lactamase encoding genes tested.
authors.affiliation: Department of Medical Microbiology, Medical University of Sofia, 2 Zdrave str., Sofia, Bulgaria.
authors.forename: Ivan G
authors.initials: IG
authors.lastname: Mitov
authors.forename: Raina T
authors.initials: RT
authors.lastname: Gergova
authors.forename: Vessela V
authors.initials: VV
authors.lastname: Ouzounova-Raykova
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D033901:Bacterial Transferrin Receptor Complex / Q000235:genetics*; D002353:Carrier State; D002648:Child; D002675:Child, Preschool; D005260:Female; D005787:Gene Frequency; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D001936:Moraxella catarrhalis / Q000235:genetics* / Q000472:pathogenicity*; D045828:Moraxellaceae Infections / Q000382:microbiology; D012141:Respiratory Tract Infections / Q000382:microbiology; D012703:Serotyping; D037521:Virulence Factors / Q000235:genetics*; D055815:Young Adult; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D033901:Bacterial Transferrin Receptor Complex; C429276:OmpE protein, Moraxella catarrhalis; D037521:Virulence Factors; C484698:outer membrane protein CD, Moraxella catarrhalis; D001618:beta-Lactamases