First Neisseria gonorrhoeae Genotyping Analysis in France: Identification of a Strain Cluster with Reduced Susceptibility to Ceftriaxone

Sexually transmitted infections are a major public health problem in France and other European countries. Particularly, surveillance data about Neisseria gonorrhoeae infections have clearly indicated an increase in the incidence of gonorrhoea in France in 2006. The French laboratories participated on voluntary basis in the RENAGO (Reseau National du Gonocoque) network and sent all of their collected strains to the National Reference Center for Neisseria gonorrhoeae. In this first French molecular epidemiological study, 93 isolates collected in 2006 and representative of the French gonorrhoea epidemiology were selected. Antibiotic susceptibility to six antibiotics was determined, and serotyping and N. gonorrhoeae multiantigen sequence typing (NG-MAST) were performed. NG-MAST identified 53 sequence types (STs), of which 13 STs contained 2 to 16 isolates. The major STs identified in France were previously described elsewhere. However, two newly described STs, ST1479 and ST1987, had only been found in France until now. ST1479 was characterized by a multiple-resistance phenotype, whereas ST1987 presented a susceptibility phenotype. Moreover, among the predominant French STs, ST225, which had already been described in many countries, comprised isolates (14/16) resistant to ciprofloxacin and with reduced susceptibility to ceftriaxone. Thus, the surveillance of resistance to antibiotics is a priority in order to adapt treatment and decrease the transmission of resistant strains. Of note, no predominant ST was identified among rectal isolates from men who have sex with men.