Original Research
Comparing effects of freezing at -196 °C and -20 °C on the viability of mastitis pathogens
Submitted: 20 May 2011 | Published: 10 February 2012
About the author(s)
Inge-Marie Petzer, Department of Production Animal Studies, University of Pretoria, Onderstepoort, South AfricaJoanne Karzis, Department of Production Animal Studies, University of Pretoria, Onderstepoort, South Africa
Theodorus J. van der Schans, Department of Production Animal Studies, University of Pretoria, Onderstepoort, South Africa
Johanna C. Watermeyer, Department of Production Animal Studies, University of Pretoria, Onderstepoort, South Africa
Norman Mitchell-Innes, Herd Husbandry Help CC, Irene, South Africa
Stephanie Eloff, Department of Production Animal Studies, University of Pretoria, Onderstepoort, South Africa
Geoffrey T. Fosgate, Department of Production Animal Studies, University of Pretoria, Onderstepoort, South Africa
Abstract
Ten samples of each organism were thawed and cultured bi-weekly until week 18 for both temperature treatments. An additional sampling was performed at week 30 for samples frozen at approximately -20 °C. Freezing and cryopreservation did not impair subsequent isolation of Streptococcus dysgalactiae, Streptococcus uberis, Enterococcus faecalis, Staphylococcus aureus (STH) (phage type lytic group III) or Sta. aureus (STA) (phage typed, other than lytic group III). Survival was indicated by the isolation of bacteria from samples, and viability by the strength of growth of the bacteria isolated. The survival of Streptococcus agalactiae decreased after week 12 and Escherichia coli after week 16 of freezing, but both organisms survived under cryogenic preservation until week 18. Coagulase-negative staphylococci survived until week 18 for both freezing and cryogenic preservation.
Both storage methods could thus contribute to the improvement of a pro-active approach towards udder health management in South African dairy herds.
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Crossref Citations
1. Evaluation of three cryoprotectants used with bovine milk affected with Mycoplasma bovis in different freezing conditions
Abd Al-Bar Al-Farha, Manouchehr Khazandi, Farhid Hemmatzadeh, Razi Jozani, Rick Tearle, Andrew Hoare, Kiro Petrovski
BMC Research Notes vol: 11 issue: 1 year: 2018
doi: 10.1186/s13104-018-3325-6