Single dose 1 g ceftriaxone for urogenital and pharyngeal infection caused by Neisseria gonorrhoeae

Objectives: To evaluate the efficacy of 1 g ceftriaxone in the treatment of urethritis, cervicitis and pharyngeal infection caused by Neisseria gonorrhoeae (N. gonorrhoeae) including the oral cephem-resistant strain with chimera penicillin-binding protein 2 (PBP-2) (cefozopran-resistant N. gonorrhoeae, CZRNG). Methods: From September 2004 to November 2006, 67 patients (27 male and 40 female) who had genital infection and/or pharyngeal infection caused by N. gonorrhoeae were enrolled in this study at five participating centers in Japan. To detect the chimera PBP-2 gene, polymerase chain reaction (PCR) was performed using established primers against the altered penA of CZRNG isolates. All patients received a single 1 g dose of ceftriaxone. Efficacy was evaluated only in those who returned for examination and culture for N. gonorrhoeae between 3 and 14 days after the treatment. Results: CZRNG isolates detected by PCR accounted for 41.7% (20/48) of urogenital infections and 60.0% (15/25) of pharyngeal infections in the treatment efficacy evaluable cases. 37 of 39 CZRNG isolates (94.9%) were multi-drug resistant isolates that had simultaneous resistance to penicillin, tetracycline, and ciprofloxacin. Nineteen patients had N. gonorrhoeae isolates in the urogenital area and pharynx simultaneously. Ceftriaxone treatment eradicated all N. gonorrhoeae isolates from 48 patients with genitourinary infection and 25 patients with pharyngeal infection. Conclusions: We report for the first time that ceftriaxone is effective in patients with gonococcal urethritis, cervicitis, and pharyngeal infection caused by CZRNG that has chimera PBP-2.