title: Neisseria gonorrhoeae MS11mkC opacity protein expression in vitro and during human volunteer infectivity studies.
abstract: OBJECTIVE
  Neisseria gonorrhoeae MS11mkC harbors 11 independently expressed opacity (Opa) protein genes with distinct in vitro expression frequencies. In experimental infections in which human male volunteers were inoculated with transparent (Opa), piliated (P+) strains, the authors associate onset of symptoms with recovery of opaque (Opa+) gonococci.
  
  
  OBJECTIVE
  In vitro and recovered (Opa) protein expression rates were compared to determine if the human host influences Opa expression.
  
  
  METHODS
  Opa expression was determined using Western immunoblot analysis; Opa sizes were determined using a scanning densitometer.
  
  
  RESULTS
  Seven of 10 Opa proteins were identified in gonococci recovered from all of the volunteers at frequencies consistent with in vitro results (Opa C, 29.5 kDa; Opa K, 30 kDa; Opa G, 31 kDa; Opa I, 32 kDa; Opa J, 33 kDa; Opa D, 34 kDa; and Opa H, 37 kDa) (P > or = 0.01, Fisher exact test). Opa B (30.5 kDa) was identified at lower than expected frequencies, whereas Opa E (31.2) and F (31.5) were identified at higher' than expected frequencies. When recovered gonococci were reanalyzed for in vitro expression frequencies, they were consistent with preinfection frequencies.
  
  
  CONCLUSIONS
  The host may influence the prevalence of some Opa proteins.
authors.affiliation: Department of Bacterial Diseases, Walter Reed Army Institute of Research, Washington DC, USA. katherine.a.schmidt@dartmouth.edu
authors.forename: K A
authors.initials: KA
authors.lastname: Schmidt
authors.forename: C D
authors.initials: CD
authors.lastname: Deal
authors.forename: M
authors.initials: M
authors.lastname: Kwan
authors.forename: E
authors.initials: E
authors.lastname: Thattassery
authors.forename: H
authors.initials: H
authors.lastname: Schneider
mesh_terms: D000942:Antigens, Bacterial / Q000096:biosynthesis* / Q000145:classification / Q000302:isolation & purification; D015153:Blotting, Western; D006069:Gonorrhea / Q000382:microbiology*; D006801:Humans; D008297:Male; D009344:Neisseria gonorrhoeae / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism* / Q000472:pathogenicity*; D014556:Urine / Q000382:microbiology
chemical_list: D000942:Antigens, Bacterial; C050308:opacity proteins