Hostname: page-component-848d4c4894-8kt4b Total loading time: 0 Render date: 2024-06-22T03:25:11.144Z Has data issue: false hasContentIssue false

Use of conventional biochemical tests and analyses of ribotype patterns for classification of micrococci isolated from dairy products

Published online by Cambridge University Press:  01 February 1999

FRANÇOISE IRLINGER
Affiliation:
INRA Laboratoire de Génie et Microbiologie des Procédés Alimentaires, Centre de Biotechnologie Agro-Industrielle, Institut National Agronomique Paris–Grignon, F-78850 Thiverval-Grignon, France
JEAN-LOUIS BERGÈRE
Affiliation:
INRA Laboratoire de Génie et Microbiologie des Procédés Alimentaires, Centre de Biotechnologie Agro-Industrielle, Institut National Agronomique Paris–Grignon, F-78850 Thiverval-Grignon, France

Abstract

Various methods were used to study 42 Gram-positive cocci belonging to the family of Micrococcaceae and isolated from dairy products. Only a few strains could be identified using the ATB 32 biochemical micromethod rapid gallery system (API). All strains were subjected to conventional biochemical tests. The results were then analysed by a numerical method using the Sokal–Michener similarity coefficient. The 42 strains were distributed into 10 clusters at the Euclidean distance of 3·2. Most (75%) of the isolates were identified at the species level, but Micrococcus luteus could not be differentiated from Mc. lylae within the Micrococcus genus. An identification method based on the analysis of ribotype patterns was then applied to the isolates and these were compared with the patterns of collection strains. Cellular DNA was cleaved by the restriction enzymes SacI and KpnI and probed with the peroxidase-labelled 16S+23S rRNA of Escherichia coli. Ribotype patterns were analysed using a Dice coefficient and the unweighted pair group method using arithmetic averages, making dendrogram construction possible. Of the strains investigated, >84% were characterized to the species level. The remaining strains were found to belong to the Arthrobacter group or were atypical Micrococcus species. Of the isolates, 52% belonged to Micrococcus luteus, 17% were identified as Kocuria varians and 7% were assigned to the Brachybacterium genus.

Type
Research Article
Copyright
Proprietors of Journal of Dairy Research 1999

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.)