Bacteriocin production, plasmid content and plasmid location of enterocin P structural gene in enterococci isolated from food sources.
OBJECTIVE
To characterize bacteriocin production, antimicrobial spectrum and plasmid content in bacteriocinogenic enterococci from foods.


RESULTS
Bacteriocinogenic Enterococcus faecium (14 isolates) and Enterococcus faecalis (three isolates) showed two different patterns of bacteriocin production in liquid broth: exponential-phase and stationary-phase production. Bacteriocin concentrates from all enterococci were inactivated by trypsin, but seldom by heat (100-117 degrees C), extremes of pH (2.0 to 9.0) or reducing agents (such as dithiothreitol). All bacteriocin concentrates were active against Listeria innocua and Listeria monocytogenes, and most were also active against many Ent. faecalis and Ent. faecium isolates. Enterococci clustered in three main groups according to their plasmid content (which included plasmids from 2.0 to 53 kb). Several isolates from different foods showed almost identical plasmid profiles. The enterocin P structural gene (entP) was detected by hybridization on plasmids of c. 19, 26 and/or 35-38 kb.


CONCLUSIONS
Enterococci from food show different patterns of bacteriocin production and different plasmid content in spite of carrying similar bacteriocin-encoding genes.


CONCLUSIONS
This study provides information on the diversity of bacteriocinogenic enterococci from food sources carrying apparently similar enterocin genes.
Abriouel
H
H
Departamento de Ciencias de la Salud, Area de Microbiología, Facultad de Ciencias Experimentales, Universidad de Jaén, Jaen, Spain.
Ben Omar
N
N
Lucas
R
R
Martínez-Cañamero
M
M
Gálvez
A
A
D001430:Bacteriocins / Q000096:biosynthesis* / Q000235:genetics; D013293:Enterococcus faecalis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D016984:Enterococcus faecium / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D005516:Food Microbiology; D010957:Plasmids
D001430:Bacteriocins; C417717:enterocin P