Outbreak of cefozopran (penicillin, oral cephems, and aztreonam)-resistant Neisseria gonorrhoeae in Japan.

We have previously reported that the Neisseria gonorrhoeae isolates from clinical failure cases treated with cefdinir and aztreonam, beta-lactams exhibited high MICs. These resistant isolates were clearly separated from the isolates exhibiting a low level of resistance to beta-lactams as shown by the MIC distribution of cefozopran. Restriction fragment length polymorphism DNA typing revealed that the outbreak of cefozopran-resistant isolates in Kitakyushu, Japan, occurred as a result of clonal spread.