Antibiotic susceptibilities, serotypes and auxotypes of Neisseria gonorrhoeae isolated in New Zealand

Abstract

Objective: The aim of the study was to determine the distribution of auxotypes and serotypes and the prevalence of antibiotic resistance among New Zealand isolates of Neisseria gonorrhoeae.

Materials and methods: A total of 486 gonococci isolated in 1988 were auxotyped, serotyped, and tested for susceptibilities to ten antibiotics.

Results: The gonococci were susceptible to all the antibiotics tested except penicillin and tetracycline. Eleven (2.2%) produced beta-lactamase, one (0.2%) showed chromosomal penicillin resistance, and 18 (3.7%) were resistant to a low-level of tetracycline. Most of the gonococci belonged to six auxotypes. The three predominant auxotypes were arginine-requiring (Arg-), non-requiring (NR), and arginine, hypoxanthine, uracil-requiring (AHU-). The majority of the isolates belonged to serogroup IB and to six serovars. The most prevalent serovars were IB-3 and IB-1. There was an association between penicillin susceptibility and auxotype or serovar among non-penicillinase producing N. gonorrhoeae (PPNG) isolates.

Conclusions: Antibiotic resistance, including penicillin resistance, remains uncommon among gonococci in New Zealand. Baselines have been established for future epidemiological studies using both auxotyping and serotyping.