Surveillance of antimicrobial susceptibilities in Neisseria gonorrhoeae in Nanjing, China, 1999-2006.
OBJECTIVE
To monitor the frequency and types of antibiotic resistance of Neisseria gonorrhoeae in Nanjing, China, between 1999 and 2006.


METHODS
beta-Lactamase production was determined by paper acidometric testing. Minimum inhibitory concentrations (MICs) to penicillin, ceftriaxone, tetracycline, ciprofloxacin, and spectinomycin were determined by agar plate dilution. Plasmid types were determined for TRNG and PPNG isolates by PCR.


RESULTS
One-thousand two-hundred and eight N. gonorrhoeae isolates were examined. The rate of PPNG rose from 8.0% (9 of 112) in 1999 to 57.36% (113 of 197) in 2004, and declined to 44.44% (88 of 198) in 2006. Prevalence of TRNG increased from 1.8% (2 of 112) in 1999 to 32.82% (65 of 198) in 2006. 99.23% (258 of 260) of TRNG contained the Dutch-type tetM gene and 2 strains contained the American-type tetM gene. All PPNG examined contained the Asian type plasmid. Among non-PPNG, chromosomally mediated resistance to penicillin varied from 57.84% (59 of 102) to 87.80% (72 of 82). Chromosomal resistance to ciprofloxacin (QRNG) was detected in 83.93% (94 of 112) of the strains in 1999 and 98.99% (196 of 198) in 2006. Eight spectinomycin-resistant N. gonorrhoeae strains were detected between 2001 and 2006. None of the gonococcal isolates tested was resistant to ceftriaxone but decreased susceptibility was observed in some strains.


CONCLUSIONS
Among N. gonorrhoeae strains isolated in Nanjing, China, plasmid mediated resistance including PPNG and TRNG increased significantly between 1999 and 2006. Chromosomally mediated resistance to both penicillin and ciprofloxacin was also high during this period. Spectinomycin resistance of N. gonorrhoeae was sporadic. Ceftriaxone and spectinomycin can be considered effective antimicrobial agents for the treatment of gonorrhea in Nanjing at the present time.
Su
Xiaohong
X
National Center for STD Control, Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing 210042, China. suxhong@yahoo.com
Jiang
Faxing
F
Qimuge
Dai
Xiuqing
X
Sun
Houhua
H
Ye
Shunzhang
S
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology; D002681:China / Q000453:epidemiology; D002939:Ciprofloxacin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D006069:Gonorrhea / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D009344:Neisseria gonorrhoeae / Q000187:drug effects* / Q000201:enzymology; D010405:Penicillinase / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D011159:Population Surveillance; D013753:Tetracycline Resistance / Q000235:genetics; D001618:beta-Lactamases / Q000096:biosynthesis
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D002939:Ciprofloxacin; D010405:Penicillinase; D001618:beta-Lactamases