Use of pyrrolidonyl peptidase to distinguish Citrobacter from Salmonella.
Lett Appl Microbiol
; 28(3): 175-8, 1999 Mar.
Article
em En
| MEDLINE
| ID: mdl-10196763
ABSTRACT
In the routine testing of foods for Salmonella, Citrobacter and other members of the Enterobacteriaceae often produce colonies which are almost indistinguishable from Salmonella on commonly used selective agars. Biochemical confirmation of such colonies can be expensive and time-consuming. It has been suggested that the enzyme pyrrolidonyl peptidase (PYRase) could be used as a rapid test to distinguish Citrobacter colonies (PYRase-positive) from Salmonella (PYRase-negative). Pure cultures of Salmonella, Citrobacter and other Enterobacteriaceae were tested for PYRase activity; all strains of Salmonella tested were PYRase-negative, and all Citrobacter tested were PYRase-positive. Inoculated and naturally contaminated food samples were tested for the presence of Salmonella by a standard cultural method. A PYR test was used to test Salmonella-like colonies isolated on selective agar and potentially, eliminate PYR-positive isolates from further biochemical testing. The test was able to screen out 6% of colonies selected from samples inoculated with Salmonella, and 43% of colonies selected from uninoculated samples.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Salmonella
/
Citrobacter
/
Técnicas de Tipagem Bacteriana
/
Piroglutamil-Peptidase I
/
Microbiologia de Alimentos
Idioma:
En
Revista:
Lett Appl Microbiol
Assunto da revista:
MICROBIOLOGIA
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Reino Unido