Genital gonorrhoea in women: a serovar correlation with concomitant rectal infection

Strains of gonococci isolated from 383 episodes of infection in women were classified serologically by means of two independently developed panels (Pharmacia (Ph) and Genetic Systems (GS] of monoclonal coagglutination reagents. Strains isolated from two groups of patients-those with concomitant genital and rectal infection (Group R) and those with genital infection in the absence of rectal infection (Group G)-were compared in order to determine whether certain strains of gonococci are isolated more often from women with concomitant rectal infection. Group R patients accounted for 126 (33%) episodes and Group G patients accounted for 223 (58%) episodes. Strains belonging to serogroup WII/III accounted for 61 (48%) Group R infections and 86 (39%) Group G infections. The difference was not statistically significant (0.1 greater than P greater than 0.05). Strains of serogroup WI could be resolved into 7 Ph- and 10 GS-serovars while strains of serogroup WII/III could be resolved into 19 Ph- and 14 GS-serovars. One GS-serovar, Bajk, was isolated from 34 (27%) Group R patients compared with 39 (17%) Group G patients. This difference was statistically significant (P = 0.05). Compared with non-Bajk isolates, Bajk strongly correlated with reduced susceptibility to penicillin: 60 (92%) Bajk isolates had minimum inhibitory concentrations (MIC) greater than or equal to 0.06 mg/l penicillin compared with 81 (33%) non-Bajk isolates (P less than 0.001). The GS-serovar Bacejk, however, was significantly less susceptible to penicillin than was serovar Bajk: 26 (90%) Bacejk isolates had MICs greater than or equal to 0.12 mg/l penicillin compared with 29 (44%) Bajk isolates (P less than 0.001). Therefore decreased susceptibility to penicillin does not lead in itself to rectal colonisation. It was concluded that certain gonococcal strains are more likely to cause concomitant rectal infection than others and that their reduced susceptibility to penicillin suggests that rectal test-of-cure cultures are essential in those women treated for anogenital infection.