Preservation of Haemophilus influenzae and Haemophilus parainfluenzae at -70 degrees C.
We have studied the viability of Haemophilus spp. preserved for 5 to 12 months at -70 degrees C. The following media were used: Laboratoire de Santé Publique du Québec (LSPQ) preservation medium, trypticase soy broth with 10 degrees C (vol/vol) glycerol and 40 degrees C (vol/vol) horse serum (TSBG), and Levinthal's broth (LB) medium. Three clinical isolates of both H. influenzae and H. parainfluenzae were used. After 5 months no differences in viability were observed between strains preserved in TSBG and strains preserved in LB, but a significant loss of viability was observed in strains preserved in LSPQ medium. No significant changes in antimicrobial susceptibility were observed after 5-month storage in any medium. After 12 months, TSBG appeared to be the most suitable cryopreservation medium for the six strains tested. We conclude that TSBG represents a good medium for the maintenance of Haemophilus spp. at -70 degrees C for up to 1 year.
Votava
M
M
Department of Microbiology, St. Anna's Faculty Hospital, 656 91 Brno, Czech Republic. mvotava@med.muni.cz
Strítecká
M
M
D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents; D003470:Culture Media; D005990:Glycerol; D006190:Haemophilus / Q000166:cytology; D006193:Haemophilus influenzae / Q000166:cytology; D006736:Horses; D010461:Peptones
D003451:Cryoprotective Agents; D003470:Culture Media; D010461:Peptones; D005990:Glycerol