Premium
Assessment of virulence factors, antibiotic resistance and amino‐decarboxylase activity in Enterococcus faecium MXVK 29 isolated from Mexican chorizo
Author(s) -
AlvarezCisneros Y.M.,
Fernández F.J.,
SainzEspuñez T.,
PonceAlquicira E.
Publication year - 2017
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/lam.12699
Subject(s) - enterococcus faecium , virulence , microbiology and biotechnology , biology , bacteria , enterococcus , antibiotic resistance , antibiotics , pathogen , streptococcaceae , biochemistry , gene , genetics
Abstract Enterococcus faecium MXVK 29 has the ability to produce an antimicrobial compound that belongs to Class II a of the Klaenhammer classification, and could be used as part of a biopreservation technology through direct inoculation of the strain as a starter or protective culture. However, Enterococcus is considered as an opportunistic pathogen, hence, the purpose of this work was to study the food safety determinants of E. faecium MXVK 29. The strain was sensitive to all of the antibiotics tested (penicillin, tetracycline, vancomycin, erythromycin, chloramphenicol, gentamicin, neomycin, kanamycin and netilmicin) and did not demonstrate histamine, cadaverine or putrescine formation. Furthermore, tyrosine‐decarboxylase activity was detected by qualitative assays and PCR . Among the virulence factors analysed for the strain, only the genes encoding the sexual pheromone cCF10 precursor lipoprotein ( ccf ) and cell‐wall adhesion ( efaA fm ) were amplified. The presence of these genes has low impact on pathogenesis, as there are no other genes encoding for virulence factors, such as aggregation proteins. Therefore , Enterococcus faecium could be employed as part of a bioconservation method, because it does not produce risk factors for consumer's health; in addition, it could be used as part of the hurdle technology in foods. Significance and Impact of the Study The use of molecular techniques has allowed, in recent years, to detect pathogenicity genes present in the genome of starter cultures used in food processing and preservation. The presence of these genes is undesirable, because horizontal transfer may occur with the natural biota of consumers. For this reason, it is important to analyse the presence of pathogenicity genes in such cultures. In this work, virulence factors and antibiotic resistance of Enterococcus faecium strain MXVK 29, producing an antimicrobial compound with high antilisterial activity, were analysed. The results indicate that the strain is safe to be used in food processing as starter culture.