Background and Objectives: Quinolone antibiotics are used widely for the treatment of gonorrhea, but resistant strains ap peared in Sydney in 1984, treatment failure with high-dose regi mens in 1991, ...and isolates with very high minimal inhibitory concentrations (MICs) (16 mg/l) in 1994. Goals: 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. Study Design: The antibiotic sensitivity, auxotype-serovar class, and geographic source of QRNG isolated in Sydney from January 1,1991 to June 30, 1995 were analyzed. Results: 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 auxotypeserovar classes in 14 isolates with high-level quinolone resistance (MIC, 16 mg/l). Conclusions: QRNG isolated in Sydney during the past dec ade originated in Asia as multiple gonococcal subtypes and in creased substantially in numbers and levels of resistance in 1995.
One hundred and thirty seven consecutive isolates of Neisseria gonorrhoeae and a further 36 selected gonococci with either chromosomal (CMRNG) or plasmid mediated (PPNG) resistance to penicillin, all ...cultured in Sydney in 1993, were found to be sensitive to cefpodoxime, an oral third generation cephalosporin antibiotic (MIC range <0.001-0.25mg/L). All isolates were also sensitive to ceftriaxone and spectinomycin. Six gonococci showed high level resistance to tetracycline (TRNG, MIC=32mg/L) and t2 had decreased susceptibility to quino-lone antibiotics (MIC range 0.06-0.5mg/L). The MIC50 and MIC90 for both cefpodoxime and ceftriaxone were highest amongst CMRNG and ceftriaxone was 2 to 4 times as active as cefpodoxime weight for weight. Cefpodoxime may be a valuable additional oral agent for the treatment of gonorrhea in Australia. The sensitivity of gonococci to cefpodoxime can probably be inferred from values obtained for ceftriaxone.
Forty three strains of Neisseria gonorrhoeae with decreased sensitivity to quinolone antibiotics were detected amongst 2141 Australian isolates of gonococci examined in the years 1984 to 1990. The ...strains examined belonged to 23 different auxotype/serovar classes, were generally more resistant to other antibiotics and, in the majority of cases, were isolated from travellers entering or returning to Australia from SE Asia. Quinolone-sensitive wild-type gonococci became less sensitive to these agents in vitro at a relatively high frequency when grown in the presence of quinolone concentrations at or around the MIC (Mean Inhibitory Concentration) of the antibiotic. Further increments in the levels of quinolone resistance of the already less-sensitive gonococci were also produced by this means, but high-level resistance to these agents was not observed. This suggests that mechanisms other than alterations in the DNA-gyrase of the organisms were responsible for the changes seen. Although spread of quinolone resistance in gonococci in Australia is unlikely to be rapid, if these antibiotics are used in therapy, treatment regimens with higher rather than lower dosages of quinolone antibiotics should be employed.
The in vitro and cytolytic properties of the hemolysin of group B streptococcus (GBS) were investigated using sheep erythrocytes and McCoy cells adapted for growth in a serum-deficient medium. The ...relationship between the hemolysin, various carrier molecules and phospholipids was examined. Starch-based carriers interfered with the inhibitory activity of phospholipids and solvents for the phospholipids reduced the activity of the hemolysin. These technical problems were resolved by use of an albumin-based carrier, a strain producing large amounts of hemolysin and sonication of the phospholipid. The hemolysin was cytolytic for McCoy cells and this activity and its hemolytic action on sheep erythrocytes were inhibited by a number of phospholipid components of surfactant. It is possible that GBS hemolysin has a direct or indirect role in the pathogenesis of the pneumonitis of early onset GBS infection.
We describe the development of the Australian gonococcal surveillance programme from February 1979 to July 1982. Participants in the programme were the major public health laboratories in each state, ...which perform quantitative sensitivity tests on about 5400 strains of Neisseria gonorrhoeae yearly. Participating laboratories conducted sensitivity tests by a standardised technique which is described, and the results from each centre were collated quarterly. Temporal and regional differences in gonococcal sensitivity patterns were noted and, in the twelve months ending June 1982, there was a trend towards a decrease in gonococci sensitive to penicillin. Increasing numbers of penicillinase producing gonococci were found, and the isolation rates of these strains varied in different regions at different times.
Data from the Australian Gonococcal Surveillance Programme (AGSP) were used to analyse changes in the patterns of gonococcal disease in Australia over the period July 1, 1981 to June 30, 1987. The ...AGSP is a continuing multicentric study of aspects of gonococcal disease and bases its analyses on laboratory-confirmed cases of gonorrhoea. The number of gonococcal isolates was highest in 1982-1983, when 6599 strains were cultured, but it fell in each subsequent year of the study until fewer than half this number was isolated in 1986-1987. The decrease in the number of isolated strains was proportionately-greater in men than in women, but in spite of this, the male-to-female ratio of disease in Australia remains unacceptably-high at two to one. In male patients, the decrease in the incidence of rectal isolates from 11.7% of all strains in 1981-1982 to 1.8% of all strains in 1986-1987 particularly was noteworthy. In female patients, pharyngeal isolates constituted an increasing proportion of strains and rose from 4.6% of all strains in 1981-1982 to 9.0% of all strains in 1986-1987; this has implications for the diagnosis and management of gonococcal disease in this group.
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