Detection of bacteriocin production and virulence traits in vancomycin-resistant enterococci of different sources.
OBJECTIVE
Three hundred and two enterococci were isolated from food, animal and clinical samples in order to evaluate the incidence of vancomycin-resistant enterococci (VRE) and bacteriocin, cytolysin, haemolysin, gelatinase production.


RESULTS
Among the isolates, 27 (8.9%) were VRE, and 17 (63%) of these showed, by the deferred antagonism method, bacteriocin production against gram-positive and some gram-negative indicators. Eight bacteriocin producers displayed by polymerase chain reaction an enterocin structural gene: six Enterococcus faecium the Enterocin A, two Enterococcus faecalis the Enterocin P genes. The enterocins AS-48, 31, L50 and 1071A/B genes were not found. Regarding the virulence factors, two VRE produced gelatinase and seven were haemolytic. Gelatinase gelE gene was found in 19 strains and cytolysin cylL(L) gene in eight. Among the strains showing the cylL(L) gene, only two E. faecalis expressed a beta-haemolysis.


CONCLUSIONS
Our results showed the persistence of VRE in food, animal and clinical samples. Many of these strains displayed antibacterial activity and sometimes different components of virulence, which could emphasize their pathogenicity.


CONCLUSIONS
This work indicates the need of a constant monitoring of enterococci in order to assess their possible pathogenic properties. The strains of interest in the food industry or used as probiotics should be tested for antibiotic resistance and virulence traits.
Sabia
C
C
Department of Biomedical Sciences, University of Modena and Reggio E., Modena, Italy.
de Niederhäusern
S
S
Guerrieri
E
E
Messi
P
P
Anacarso
I
I
Manicardi
G
G
Bondi
M
M
D001426:Bacterial Proteins / Q000235:genetics; D001430:Bacteriocins / Q000032:analysis / Q000096:biosynthesis*; D019729:Carbon-Oxygen Ligases / Q000235:genetics; D002611:Cheese; D004269:DNA, Bacterial / Q000032:analysis; D016983:Enterococcus / Q000302:isolation & purification / Q000378:metabolism*; D013293:Enterococcus faecalis / Q000302:isolation & purification / Q000378:metabolism; D016984:Enterococcus faecium / Q000302:isolation & purification / Q000378:metabolism; D004783:Environmental Microbiology; D018093:Gelatinases / Q000235:genetics; D006460:Hemolysin Proteins / Q000235:genetics; D008826:Microbial Sensitivity Tests; D054353:Perforin / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods; D020713:Vancomycin Resistance; D014774:Virulence
D001426:Bacterial Proteins; D001430:Bacteriocins; D004269:DNA, Bacterial; D006460:Hemolysin Proteins; C071437:VanA ligase, Bacteria; C107799:enterocin A; C417717:enterocin P; D054353:Perforin; D018093:Gelatinases; D019729:Carbon-Oxygen Ligases