Tendency toward increase in the frequency of isolation of beta-lactamase-nonproducing Neisseria gonorrhoeae exhibiting penicillin resistance, and recent emergence of multidrug-resistant isolates in Japan.
Six hundred and ninety-nine strains of Neisseria gonorrhoeae were examined by the agar dilution method according to the M7-A5 guidelines established by the National Committee for Clinical Laboratory Standards (NCCLS) determine to their beta-lactamase production and susceptibility to penicillin G, cefixime, ceftriaxone, tetracycline, spectinomycin, ciprofloxacin, and azithromycin. The frequency of isolation of penicillinase-producing N. gonorrhoeae decreased gradually, from 7.3% of the test isolates (55 isolates) in 1995 to about 1% in 1998 and 1999. In contrast, while beta-lactamase-nonproducing N. gonorrhoeae exhibiting chromosomally mediated penicillin G resistance were not isolated from clinical specimens in 1995, the incidence of isolation of such resistant strains increased markedly, to 8.2% of 159 isolates, in 1997 and 14.9% of 242 isolates in 1999. The incidence of the isolation of tetracycline-resistant strains also increased between 1996 (none detected) and 1998-1999 (each 7%-8%), and a tendency towards an increase in the frequency of isolates of ciprofloxacin-resistant strains was also observed between 1995 (9.8%) and from 1997 to 1999 (more than 20%). There were no isolates resistant to any two antibiotics among penicillin G, tetracycline, and ciprofloxacin until 1997, but, in subsequent surveys in recent years, multidrug-resistant isolates (resistant to penicillin G, tetracycline, and ciprofloxacin) were detected in 1999.
Kobayashi
Intetsu
I
Chemotherapy Division, Mitsubishi Kagaku Bio-Clinical Laboratories, Tokyo, Japan. mbc-ka@sa2.so-net.ne.jp
Kanayama
Akiko
A
Saika
Takeshi
T
Nishida
Minoru
M
Nakayama
Hiroshi
H
Tanaka
Masatoshi
M
Naito
Seiji
S
D002876:Chromosomes, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D009344:Neisseria gonorrhoeae / Q000187:drug effects / Q000201:enzymology / Q000302:isolation & purification*; D010403:Penicillin Resistance; D001618:beta-Lactamases / Q000096:biosynthesis*
D001618:beta-Lactamases