| Issue |
Lait
Volume 46, Number 453-454, 1966
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|---|---|---|
| Page(s) | 131 - 140 | |
| DOI | https://doi.org/10.1051/lait:1966453-4548 | |
DOI: 10.1051/lait:1966453-4548
Recherche des staphylocoques pathogènes dans le lait et les produits laitiers
G. THIEULIN, D. BASILLE, J. PANTALEON, R. ROSSET, Y. GANDON and A. PETITLaboratoires du Service vétérinaire sanitaire de Paris et du département de la Seine
Abstract - Baird-Parker's agar enables to number directly pathogenic staphylococcus in milk and milk products.
With " desoxyribonuclease test ", used as a confirmatory test, the proportion of confirmed colonies amounts to 96 p. 100 for earlv bacterial colonies (24 hours' incubation) and 83 p. 100 for late colonies (48 hours' incubation) which schowed the characteristic aspect on Baird-Parker's agar (a black pigmentation and a wide transparent halation). The same rate is only 43 p. 100 on doubtful colonies which developped on " mannitol salt agar ", Two precautionary measures, however, seem to be necessary:
1) to take a first reading after 24 hours and a second one after 48 hours.
2) to carry out experiments and counts within two different dilution rates