Preservation of Neisseria gonorrhoeae: should swabs be refrigerated or not?: Neisseria gonorrhoeae preservation.

Although molecular diagnosis has replaced culture as the reference technique in gonococcal infection, conventional culture is still performed. The aim was to compare the survival of Neisseria gonorrhoeae (NG) in transport swabs at room temperature (RT) and at 4°C. Fifty-four NG isolates were tested. A 1.5×108CFUmL-1 suspension was prepared for each strain, in which two swabs (Amies liquid medium with flocked swabs) were absorbed; one was preserved at RT and the other at 4°C. At 24 and 48h, 150μL of Amies medium were plated in Thayer Martin agar. The recovery percentage was significantly higher for the swabs kept at 4°C than for those kept at RT, both at 24h (94.4% vs. 16.7%), and at 48h (37% vs. 0%). This study clearly demonstrates the higher survival of NG when transport swabs are kept refrigerated. Modifying the guidelines could greatly improve the efficiency of microbiological diagnosis of the gonococcal infection.