Quinolone-Resistant Neisseria gonorrhoeae Isolated in Sydney, Australia, 1991 to 1995

Abstract

Quinolone antibiotics are used widely for the treatment of gonorrhea, but resistant strains appeared in Sydney in 1984, treatment failure with high-dose regimens in 1991, and isolates with very high minimal inhibitory concentrations (MICs) (16 mg/l) in 1994. To examine the frequency, source, and characteristics of Quinolone-resistant Neisseria gonorrhoeae (QRNG) in Sydney from 1991 to 1995 and to compare these data with those obtained from 1984 to 1990. The antibiotic sensitivity, auxotype-serovar class, and geographic source of QRNG isolated in Sydney from January 1, 1991 to June 30, 1995 were analyzed. One hundred seven QRNG were isolated from 97 patients from 1991 to 1995. The number, proportion, and MICs of QRNG increased slowly in the first 4 years of the study and rapidly in the last 6 months. Most QRNG were isolated from travelers entering Sydney from Asia. Twenty-seven different auxotype-serovar classes were detected including 6 auxotype-serovar classes in 14 isolates with high-level quinolone resistance (MIC, 16 mg/l). QRNG isolated in Sydney during the past decade originated in Asia as multiple gonococcal subtypes and increased substantially in numbers and levels of resistance in 1995.