Neisseria gonorrhoeae MS11mkC opacity protein expression in vitro and during human volunteer infectivity studies.
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.
Schmidt
K A
KA
Department of Bacterial Diseases, Walter Reed Army Institute of Research, Washington DC, USA. katherine.a.schmidt@dartmouth.edu
Deal
C D
CD
Kwan
M
M
Thattassery
E
E
Schneider
H
H
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
D000942:Antigens, Bacterial; C050308:opacity proteins