Neisseria gonorrhoeae isolated from disseminated and localised infections in pre-penicillin era. Auxotypes and antibacterial drug resistances.

Interest in the evolution of gonococcal auxotrophy led to a study of 72 strains isolated between 1935 and 1948 from the urogenital tract (57 patients), the eye (two patients), and from disseminated gonococcal infections (11 patients and probably two others). Two cervical isolates with nutritional requirements for proline, arginine, histidine, and biotin were oxidase-positive, Gram-negative diplococci, but their identity as Neisseria gonorrhoeae was uncertain because they were atypically susceptible to colistin and did not produce acid in glucose media. The N gonorrhoeae strains were highly susceptible to 11 other antibacterial drugs but not to sulphadiazine. Defects of one or more pathways for the biosynthesis of methionine, proline, arginine, threonine, lysine, the branched-chain amino acids, hypoxanthine, and thiamine pyrophosphate were found in 39 of the 70 strains, including four isolated in the presulphanilamide era. Unexpectedly, methionine was required for the growth of 11 (21%) of the 52 Danish strains and for 13 (72%) of 18 strains isolated in the USA. The Danish strains included 28 (54%) that did not require any of the compounds used for differentiating auxotypes, whereas this type was represented by only three (17%) of the USA strains. None of the gonococci required uracil or other pyrimidines. This suggests that the requirements for arginine, hypoxanthine, and uracil commonly found in recent isolates from disseminated gonococcal infections probably evolved treatment with sulphonamide was replaced by penicillin.

Recent developments in the laboratory diagnosis of gonococcal infections.

The author reviews the more important studies on the laboratory diagnosis of gonococcal infections published since 1964. The most significant new developments are the use (a) of fluorescent antibody techniques and (b) of selective media for the identification and isolation of Neisseria (N.) gonorrhoeae. The sensitivity and specificity of culture methods and of the direct "delayed" fluorescent antibody technique (FAT), both at their best, are very similar, but the FAT allows for more rapid reporting. The results of the direct "undelayed" FAT can be given even more rapidly, but, especially with specimens from women, it is less sensitive than culture or the direct "delayed" FAT. The use of a selective medium facilitates the recognition and identification of N. gonorrhoeae, but the advantage of a selective medium over a non-selective medium depends very much on the skill of the technical personnel involved. One disadvantage is the existence of gonococcal strains that are very sensitive to the antibiotics used hitherto for the suppression of Gram-positive contaminants. Ideally, selective medium should be used in combination with the direct "delayed" FAT after growth on non-selective medium. Other new achievements are a complete, chemically defined, protein-free liquid medium for the culture of fastidious Neisseriae; a commercially available chemically defined enrichment supplement; and a new specimen-transport kit using Stuart's medium.The author also reviews recent reports which suggest that the in vitro sensitivity of N. gonorrhoeae to penicillin and other antibiotics used for treating gonorrhoea is generally decreasing; however, some reports of increasing sensitivity have lately come from Scandinavia.

Antibiotic sensitivity of gonococcal strains isolated in the South-East Asia and Western Pacific regions in 1961-68.

A decreasing susceptibility of gonococcal strains to penicillin and other antibiotics has been observed in most parts of the world, including the WHO South-East Asia and Western Pacific regions. In the Neisseria Department, Statens Seruminstitut, Copenhagen, the antibiotic sensitivity of about 100 gonococcal strains from these regions has been determined. The strains were collected during 2 periods, one in 1961 (Ceylon and the Philippines), the other in 1967-68 (Thailand, Taiwan, Viet-Nam and Hong Kong).It was found that the incidence of gonococcal strains with decreased susceptibility to penicillin and most of the more generally used antibiotics is increasing in these regions. The distribution of the 50% inhibitory concentrations of penicillin, tetracycline, streptomycin and spiramycin was similar for the strains isolated in the Philippines in 1961 and for those from the other areas in 1967-68, namely, strains with "normal sensitivity" were lacking. Most of the strains collected in 1961 were fully sensitive to chloramphenicol and erythromycin, whereas about 25% of the strains collected in 1967-68 were only moderately sensitive to chloramphenicol, and about 75% were moderately sensitive to erythromycin; 1 strain was resistant to erythromycin. Only 10% of these strains were sensitive to all the antibiotics employed.In contrast to these findings, several authors report an increasing susceptibility of the gonococcal strains in northern Europe. Possible explanations for the reversion to "normal sensitivity" are discussed briefly.