Premium
Storage of pathogenic leptospires in liquid nitrogen
Author(s) -
Palit A.,
Haylock L. M.,
Cox J. C.
Publication year - 1986
Publication title -
journal of applied bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 0021-8847
DOI - 10.1111/j.1365-2672.1986.tb04304.x
Subject(s) - cryoprotectant , liquid nitrogen , serotype , ampoule , leptospira interrogans , virulence , glycerol , nitrogen , microbiology and biotechnology , leptospira , biology , chemistry , cryopreservation , biochemistry , fishery , organic chemistry , embryo , gene
The virulence and viability of various serovars of Leptospira interrogans were successfully preserved by storage in liquid nitrogen. Dimethyl sulphoxide at a final concentration of 2.5% (v/v) was added as cryoprotectant to a culture of leptospires grown in Ellinghausen‐McCullough‐Johnson‐Harris medium. Ampoules were cooled at a controlled rate of 1°–3°C/min to −70°C, then transferred to the liquid phase of a liquid nitrogen storage unit. Glycerol was discounted as a cryoprotectant as it was found to be approximately 10 times more toxic than dimethyl sulphoxide to four of five serovars used in this study. The viability of nine strains has so far been observed over a period of 8–22 months storage in liquid nitrogen and full viability of all strains has been preserved over this period. Virulence of strains of serovars pomona and hardjo was well preserved, as demonstrated by challenge tests in guinea pigs and domestic pigs.