Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-26T04:20:25.621Z Has data issue: false hasContentIssue false

Improved bioluminescent assay of somatic cell counts in raw milk

Published online by Cambridge University Press:  02 June 2008

Valery G Frundzhyan
Affiliation:
Chemistry Department, Lomonosov Moscow State University, Moscow 119991, Russia
Inna M Parkhomenko
Affiliation:
Biology Department, Lomonosov Moscow State University, Moscow 119991, Russia
Lubov Y Brovko
Affiliation:
Canadian Research Institute for Food Safety, University of Guelph, Ontario N1G 2W1, Canada
Natalia N Ugarova*
Affiliation:
Chemistry Department, Lomonosov Moscow State University, Moscow 119991, Russia
*
*For correspondence; e-mail: unn@enz.chem.msu.ru

Abstract

Somatic cell count (SCC) in milk is considered to be a valuable indicator of cow mastitis. For assessment of SCC in milk, the bioluminescent assay based on determination of ATP from somatic cells ([ATPsom]) in milk was proposed earlier. However, this assay is still not widely used in practice owing to lower reliability compared with conventional methods such as direct microscopy and flow cytometry. We revised the bioluminescent SCC assay and developed a simple protocol based on determination of the total non-bacterial ATP concentration in milk. It was shown that the novel ATP-releasing agent Neonol-10 (oxy-ethylated iso-nonyl phenol) has superior performance providing 100% lysis of somatic cells while not disrupting bacterial cells of milk at a concentration of 1·5% w/w. There was high correlation (R2=0·99) between measured bioluminescence and SCC as measured by direct microscopy. The observed detection limit of the bioluminescent milk SCC assay was as low as 900 cell/ml, time of analysis was 2–3 min per sample. The proposed method has high potential for on-site mastitis diagnostics.

Type
Research Article
Copyright
Copyright © Proprietors of Journal of Dairy Research 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bossuit, R 1978 Usefulness of an ATP assay technique in evaluating the somatic cell content in milk. Milchwissenschaft 33 1113Google Scholar
Brovko, LY, Trdatyan, IY & Ugarova, NN 1991 Optimization of the bioluminescent assay of microbial biomass. Applied Biochemistry and Microbiology (Translated from Prikladnaya Biokhimiya i Mikrobiologiya) 27 108113Google Scholar
Brovko, LY, Froundjian, VG, Babunova, VS & Ugarova, NN 1999 Quantitative assessment of bacterial contamination of raw milk using bioluminescence. Journal of Dairy Research 66 627631CrossRefGoogle Scholar
Emanuelson, U, Olsson, T, Mattila, T, Åström, G & Holmberg, O 1988 Effects of parity and stage of lactation on adenosine triphosphate, somatic cell count and antitrypsin content in cows' milk. Journal of Dairy Research 55 4955CrossRefGoogle ScholarPubMed
Hillerton, JE 1999 Redefining mastitis based on somatic cell count. IDF Bulletin 345 46Google Scholar
Ingalls, W 1998 Somatic cells, mastitis and milk Quality. The DairyBiz Archive 5Google Scholar
Lundin, A 1984 Extraction and automated luminometric assay of ATP, ADP and AMP. In Analytical Application of Bioluminescence and Chemiluminescence, pp. 491502 (Ed. Kricka, LJ et al. ). Orlando FL, USA: Academic PressGoogle Scholar
Miller, RH, Paape, MJ & Acton, JC 1986 Comparison of milk somatic cell counts by Coulter and Fossomatic counters. Journal of Dairy Science 69 19421946Google Scholar
Pyörälä, S 2003 Indicators of inflammation in the diagnosis of mastitis. Veterinary Research 34 565578CrossRefGoogle Scholar
Richardson, T, McGann, TCA & Kearney, RD 1980 Levels and location of adenosine 5 triphosphate (ATP) in bovine milk. Journal of Dairy Science 47 9196Google ScholarPubMed
Ruegg, PL & Reinemann, DJ 2002 Milk quality and mastitis tests. Bovine Practice 36 4154CrossRefGoogle Scholar
Theron, DP, Prior, BA & Lategan, PM 1986 Determination of bacterial ATP levels in raw milk: selectivity of non-bacterial ATP hydrolysis. Journal of Food Protection 49 47CrossRefGoogle ScholarPubMed
Ugarova, NN, Dukhovich, AF, Shvets, SV, Philippova, NY & Berezin, IV 1987 Kinetics of the inactivation of the protein-lipid complex, firefly luciferase, by sodium deoxycholate and its reactivation by phosphatidylcholine. Biochemica et Biophysica Acta 921 463472Google ScholarPubMed