title: Preservation of Neisseria gonorrhoeae at -20 degrees C.
abstract: To explore the feasibility of preserving Neisseria gonorrhoeae at -20 degrees C, we studied its viability quantitatively and qualitatively for 12 and 18 months, respectively, in the following media: a gelatin-based medium used mainly to prepare dried gelatin discs (S. Yamai, Y. Obara, T. Nikkawa, Y Shimoda, and Y. Miyamoto, Br. J. Vener. Dis. 55:90-93, 1979), a simplified version (LSPQ preservation medium), and Trypticase soy broth with 10% (vol/vol) glycerol, a medium commonly used for preservation at -70 degrees C. The latter was studied for 4 months only. Four reference strains and two clinical isolates of N. gonorrhoeae were used. The storage temperature was rigorously preadjusted and monitored at -20 +/- 1 degree C during the entire project. After 12 months of storage, all strains remained viable in both gelatin-based media, whereas a significant loss of viability was observed in Trypticase soy broth-10% glycerol after only 4 months. After 18 months, five strains were still viable in both gelatin-based media and no significant difference was observed between antimicrobial susceptibility results and those of the original strains preserved at -70 degrees C. On the basis of these results, we believe that LSPQ preservation medium represents a good alternative for the storage of N. gonorrhoeae at -20 degrees C for at least a year. Furthermore, it is easy to prepare and use and can by stored at 4 to 8 degrees C for a year prior to use.
authors.affiliation: Laboratoire de Santé Publique due Québec, Sainte-Anne-de-Bellevue, Canada.
authors.forename: P S
authors.initials: PS
authors.lastname: Harbec
authors.forename: P
authors.initials: P
authors.lastname: Turcotte
mesh_terms: D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents; D003470:Culture Media; D005069:Evaluation Studies as Topic; D006801:Humans; D009344:Neisseria gonorrhoeae / Q000302:isolation & purification; D012015:Reference Standards; D013696:Temperature; D013997:Time Factors
chemical_list: D003451:Cryoprotective Agents; D003470:Culture Media