EDP Sciences Journals List
Advanced Search
Subscriber Authentication Point
Home All issues Volume 87/6 Article
Free access article

Issue Lait
Volume 87, Number 6, November-December 2007
Page(s) 587 - 601
DOI http://dx.doi.org/10.1051/lait:2007031
Published online 04 January 2008

Lait 87 (2007) 587-601
DOI: 10.1051/lait:2007031

Incidence of virulence in bacteriocin-producing enterococcal isolates

Hittu Gupta and Ravinder Kumar Malik

National Dairy Research Institute, Karnal, Haryana, India

(Received 6 February 2007 - Accepted 24 May 2007 - Published online 4 January 2008)

Abstract - Enterococci isolated from a total number of 68 dairy products and 28 human fecal samples were screened for bacteriocin production. The incidence of the bacteriocin-production trait was highest among the cream samples (33.51%), followed by dahi samples (15.55%), raw milk samples (9.51%), Cheddar cheese (9.2%) samples and human feces (4.72%). The isolates showed antilisterial effect besides activity against other lactic acid bacteria. Sixty potent bacteriocin-producing isolates of enterococci were evaluated for the incidence of virulence characters for their safe exploitation. None of the isolates was found to exhibit gelatinase, DNAse or $\beta $-hemolysis activity. Furthermore, only 4 bacteriocin-producing isolates among 60 were observed to be vancomycin-resistant. It was concluded that bacteriocin-producing Enterococcus strains lacking hemolytic activity and not carrying vancomycin resistance genes may be safely exploited as starter cultures, co-cultures or probiotics.


Résumé - Incidence de la virulence d'isolats d'entérocoques produisant une bactériocine
Des entérocoques isolés de 68 produits laitiers et 28 échantillons fécaux humains ont été criblés pour leur production de bactériocine. L'incidence de ce caractère était maximale dans les échantillons de crème (33,51 %), suivis des échantillons de dahi (15,55 %), de lait cru (9,51 %), fèces humains (4,72 %) et fromage Cheddar (9,2 %). Outre leur activité contre les autres bactéries lactiques, les isolats avaient un effet anti-listeria. Soixante isolats d'entérocoques ayant la capacité de production de bactériocine ont été évalués pour l'incidence de leurs caractères de virulence sur leur sécurité d'emploi. Aucun des isolats n'a montré d'activité gélatinase, DNAse et $\beta $-hémolyse. De plus, seuls 4 d'entre eux se sont avérés résistants à la vancomycine. Il a été conclu que les souches d'Enterococcus produisant une bactériocine, qui n'ont pas d'activité hémolytique et ne portent pas de gènes de résistance à la vancomycine, présentent une sécurité suffisante pour leur emploi dans des levains, cocultures ou probiotiques.


Key words: bacteriocin / Enterococcus / enterocin / vancomycin / starter culture

Mots clés : bactériocine / Enterococcus / entérocine / vancomycine / levain

Corresponding author: rkm.micro@gmail.com

© INRA, EDP Sciences 2007


What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.
  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.