Sensitivity to penicillin of gonococci in different racial groups

The distribution of the sensitivity to penicillin of gonococci isolated from 631 men and 290 women was analysed in relation to the racial origin of the patients and the type of source contact alleged by the men. No difference in the sensitivity patterns was found between strains from white patients from the United Kingdom and those from immigrants from the Caribbean area. Asian men harboured significantly more insensitive strains than men of other racial groups. Men of Caribbean stock who had been born in this country had significantly more infections due to fully sensitive strains. The reasons for these variations are not known, but one contributory factor may be differences within the racial groups in the proportions of infections contracted from prostitutes.     

Sensitivity to penicillin of gonococci in different racial groups.

The distribution of the sensitivity to penicillin of gonococci isolated from 631 men and 290 women was analysed in relation to the racial origin of the patients and the type of source contact alleged by the men. No difference in the sensitivity patterns was found between strains from white patients from the United Kingdom and those from immigrants from the Caribbean area. Asian men harboured significantly more insensitive strains than men of other racial groups. Men of Caribbean stock who had been born in this country had significantly more infections due to fully sensitive strains. The reasons for these variations are not known, but one contributory factor may be differences within the racial groups in the proportions of infections contracted from prostitutes.     

Nutritional requirements and penicillin susceptibilities of gonococci from pharyngeal and anogenital sites.

Neisseria gonorrhoeae was isolated from 5.9% of oropharyngeal specimens obtained from patients attending a clinic for sexually transmitted diseases. Oropharyngeal isolates from 69 patients and anogenital isolated from 97 other patients attending the same clinic were compared. Many of the gonococci could be differentiated by the compounds required for growth in chemically defined media or by differences in the minimum inhibitory concentration (MIC) of penicillin G. Strains with requirements for either proline (Pro-) or arginine (Arg-) or for none of the compounds that are used for differentiation (zero phenotype) were more common in the oropharynx (91.3% of patients) than in anogenital sites (73.2% of patients). On the other hand, gonococci with multiple requirements that include arginine, hypoxanthine, and uracil (AHU strains) were present in oropharyngeal specimens from only three patients (4.4%), but were isolated from anogenital specimens from 18 patients (18.6%). A high susceptibility to penicillin characterised the AHU strains from all sites, as others have reported. The penicillin MIC ranged from 0.003-0.72 microgram/ml for strains with Pro-, Arg-, and zero phenotypes. However, a penicillin MIC greater than or equal to 0.42 microgram/ml was found for 17.6% of oropharyngeal isolates of these types, but for only 4.1% of Pro-, Arg-, and zero isolates from anogenital sites. None of these moderately resistant strains produced beta-lactamase. Our findings indicate that gonococci differ in their ability to colonise the oropharynx successfully.     

Inactivation of gonococci by procaine penicillin in vivo. A pilot study.

A pilot study was carried out of 25 male volunteers with gonococcal urethritis. After intramuscular administration of 3 megaunits procaine penicillin and 1 g oral probenecid the urethral culture results for Neisseria gonorrhoeae remained positive up to five hours and thereafter became negative. These results may be useful in providing guidelines for advice on the duration of sexual abstinence following treatment. It is suggested that similar studies should be carried out in women.     

Nutritional requirements and penicillin susceptibilities of gonococci from pharyngeal and anogenital sites.

Neisseria gonorrhoeae was isolated from 5.9% of oropharyngeal specimens obtained from patients attending a clinic for sexually transmitted diseases. Oropharyngeal isolates from 69 patients and anogenital isolated from 97 other patients attending the same clinic were compared. Many of the gonococci could be differentiated by the compounds required for growth in chemically defined media or by differences in the minimum inhibitory concentration (MIC) of penicillin G. Strains with requirements for either proline (Pro-) or arginine (Arg-) or for none of the compounds that are used for differentiation (zero phenotype) were more common in the oropharynx (91.3% of patients) than in anogenital sites (73.2% of patients). On the other hand, gonococci with multiple requirements that include arginine, hypoxanthine, and uracil (AHU strains) were present in oropharyngeal specimens from only three patients (4.4%), but were isolated from anogenital specimens from 18 patients (18.6%). A high susceptibility to penicillin characterised the AHU strains from all sites, as others have reported. The penicillin MIC ranged from 0.003-0.72 microgram/ml for strains with Pro-, Arg-, and zero phenotypes. However, a penicillin MIC greater than or equal to 0.42 microgram/ml was found for 17.6% of oropharyngeal isolates of these types, but for only 4.1% of Pro-, Arg-, and zero isolates from anogenital sites. None of these moderately resistant strains produced beta-lactamase. Our findings indicate that gonococci differ in their ability to colonise the oropharynx successfully.     

Influence of copper salts on gonococci.

No difference in the incidence of gonorrhoea was observed at a venereal disease clinic between women using a copper-coil intrauterine device (IUD) and women using oral contraceptives. Experiments in vitro demonstrated that copper sulphate has a deleterious effect on Neisseria gonorrhoeae, but the presence of serum protects the gonococci from the toxic effect of copper ions.     

Effect of nitroimidazole therapy on the demonstration of gonococci]

The minimal inhibitory concentration of metronidazole and tinidazole lies between 4000 micrograms/ml and 7.8 micrograms/ml. Drug levels are present in this range for 2--5 hours in genital discharge following single dose oral therapy with 2 g tinidazole or 1.5 g metronidazole. Therefore, 5-nitroimidazole derivatives exert a bacteriostatic effect in the genital region at least on the more sensitive strains. As shown in our experiments, otherwise reliable laboratory procedures for the demonstration of gonococci may yield false negative results, if specimens for culture are obtained at an inappropriate time.