The third nationwide surveillance of antimicrobial susceptibility against Neisseria gonorrhoeae from male urethritis in Japan, 2016-2017.

Neisseria gonorrhoeae is one of the important pathogens of sexually transmitted infections. N. gonorrhoeae is rapidly becoming antimicrobial resistant, and there are few drugs that are effective in the initial treatment of gonorrhea. To understand the trends of antimicrobial susceptibility of N. gonorrhoeae, the Surveillance Committee of the Japanese Society of Infectious Diseases, the Japanese Society for Chemotherapy, and the Japanese Society of Clinical Microbiology conducted the third nationwide antimicrobial susceptibility surveillance of N. gonorrhoeae isolated from male urethritis. The specimens were collected from male patients with urethritis at 30 facilities from May 2016 to July 2017. From the 159 specimens collected, 87 N. gonorrhoeae strains were isolated, and 85 were tested for susceptibility to 21 antimicrobial agents. All strains were non-susceptible to penicillin G. Seven strains (8.2%) were ß-lactamase-producing strains. The rates of susceptibility to cefixime and cefpodoxime were 96.5% and 52.9%, respectively. Three strains were non-susceptible with a minimum inhibitory concentration (MIC) of 0.5 mg/L for cefixime. None of the strains were resistant to ceftriaxone or spectinomycin. The susceptibility rate for ciprofloxacin was 23.5% (20 strains), and no strains showed intermediate susceptibility. The susceptibility rate against azithromycin was 81.2%, with one strain isolated with a MIC of 8 mg/L against azithromycin. The results of this surveillance indicate that ceftriaxone and spectinomycin, which are currently recommended for gonococcal infections in Japan, appear to be effective. It will be necessary to further expand the scale of the next surveillance to understand the current status of drug-resistant N. gonorrhoeae in Japan.

Nationwide surveillance of the antimicrobial susceptibility of Chlamydia trachomatis from male urethritis in Japan: Comparison with the first surveillance report.

The Urogenital Sub-committee and the Surveillance Committee of the Japanese Society of Chemotherapy, The Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology conducted the second nationwide surveillance of the antimicrobial susceptibility of Chlamydia trachomatis. In this second surveillance study, clinical urethral discharge specimens were collected from patients with urethritis in 26 hospitals and clinics from May 2016 to July 2017. Based on serial cultures, the minimum inhibitory concentration (MIC) could be determined for 41 isolates; the MICs (MIC90) of ciprofloxacin, levofloxacin, tosufloxacin, sitafloxacin, doxycycline, minocycline, erythromycin, clarithromycin, azithromycin and solithromycin were 2 µg/ml (2 µg/ml), 1 µg/ml (0.5 µg/ml), 0.25 µg/ml (0.25 µg/ml), 0.125 µg/ml (0.063 µg/ml), 0.125 µg/ml (0.125 µg/ml), 0.25 µg/ml (0.25 µg/ml), 0.031 µg/ml (0.031 µg/ml), 0.25 µg/ml (0.125 µg/ml), and 0.016 µg/ml (0.008 µg/ml), respectively. In summary, this surveillance project did not identify any strains resistant to fluoroquinolone, tetracycline, or macrolide agents in Japan. In addition, the MIC of solithromycin was favorable and lower than that of other antimicrobial agents. However, the MIC of azithromycin had a slightly higher value than that reported in the first surveillance report, though this might be within the acceptable margin of error. Therefore, the susceptibility of azithromycin, especially, should be monitored henceforth.