ABSTRACT
<p><b>OBJECTIVE</b>To investigate the genotype and characteristics of Neisseria gonorrhoeae (N.gonorrhoeae) isolates with reduced susceptibility to ceftriaxone in Shenzhen from 2009 to 2011.</p><p><b>METHODS</b>A total of 296 N.gonorrhoeae isolates were collected in Shenzhen from 2009 to 2011.ceftriaxone strains (minimum inhibitory concentration between 0.06 and 0.50 µg/ml) were determined by agar dilution method.Logistic regression was used to analyze the associated factors of ceftriaxone N.gonorrhoeae infection.Neighbor-joining (NJ) phylogenetic tree analysis and N.gonorrhoeae multi antigen sequence typing (NG-MAST) were performed on all ceftriaxone isolates and susceptible control isolates randomly selected in accordance with the principle of 1: 1 sampling.</p><p><b>RESULTS</b>No isolates displayed resistance to ceftriaxone, whereas 53(17.9%) showed reduced susceptibility to ceftriaxone among 296 isolates.Only antibiotic use in recent two months was associated with ceftriaxone isolates infection (OR = 3.080, 95%CI: 1.376-6.894) . Among the ceftriaxone isolates, 48 different ST were identified including 5 STs (ST1768, ST3927, ST641, ST7076 and ST7078) containing 2 isolates and 43 single STs. There were 26 STs previously reported from HongKong in China.Low sensitive strains clustering was not observed by NJ phylogenetic tree.</p><p><b>CONCLUSION</b>The proportion of ceftriaxone strains among the 296 N.gonorrhoeae isolates collected from 2009 to 2011 in Shenzhen is high. The STs of ceftriaxone strains may have unique epidemic features in Shenzhen.</p>