Genetic diversity of Enterococcus faecium isolated from Bryndza cheese (original) (raw)
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Molecular identification and diversity of enterococci isolated from Slovak Bryndza cheese
The Journal of General and Applied Microbiology, 2006
Three hundred and eight presumed enterococcal isolates were recovered from Bryndza, a soft sheep milk cheese. The cheese samples were obtained from five different commercial distributors in Slovakia and were taken at three different seasonal intervals. All isolates were identified to the species level using genotypic tools. Species-specific PCR using ddl genes highlighted the predominance of Enterococcus faecium (176 isolates) and assigned 50 isolates to the species Enterococcus faecalis. The remaining 82 isolates were classified using repetitive element sequence-based polymerase chain reaction (PCR) with primer (GTG) 5-(GTG) 5-PCR, in combination with phenylalanyl-tRNA synthase gene (pheS) sequence analysis and by whole-cell protein analysis (SDS-PAGE). These strains were identified as Enterococcus durans (59 strains), Enterococcus italicus (8 strains), Enterococcus casseliflavus (3 strains), Enterococcus gallinarum (3 strains), Enterococcus hirae (1 strain), and 8 strains were members of the species Lactococcus lactis. Of the seven enterococcal species isolated, three of them, E. durans, E. faecalis and E. faecium were present in all samples studied, with E. faecium as the predominant one. The precise identification of enterococci in Bryndza cheese is an essential step in the process of evaluation of their functional properties which will be further studied and assessed.
Enterococcus lactis sp. nov., from Italian raw milk cheeses
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY, 2012
Ten atypical Enterococcus strains were isolated from Italian raw milk cheeses. The 16S rRNA gene, phenylalanyl-tRNA synthase alpha subunit (pheS), RNA polymerase alpha subunit (rpoA) and the 16S-23S rRNA intergenic transcribed spacer (ITS) sequences, randomly amplified polymorphic DNA (RAPD) PCR and the phenotypic properties revealed that the isolates represent a novel enterococcal species. On the basis of 16S rRNA gene sequence analysis, the isolates were closely related to Enterococcus hirae ATCC 8043 T , Enterococcus durans CECT 411 T and Enterococcus faecium ATCC 19434 T , with 98.8, 98.9 and 99.4 % sequence similarity, respectively. On the basis of sequence analysis of the housekeeping gene pheS, the reference strain, BT159 T , occupied a position separate from E. faecium LMG 16198. The group of isolates could be easily differentiated from recognized species of the genus Enterococcus by 16S-23S rRNA ITS analysis, RAPD-PCR and phenotypic characteristics. The name Enterococcus lactis sp. nov. is proposed, with BT159 T (5DSM 23655 T 5LMG 25958 T ) as the type strain.
Journal of microbiology, biotechnology and food sciences, 2022
In this study, Enterococcus faecalis H1041 which was isolated from the traditional Bulgarian green cheese was characterized in depth by a whole-genome sequencing performed on the Illumina HiSeq platform using 2 x 150 bases paired-end reads mode. The bioinformatic analysis performed only with free online tools revealed that the strain resembles other cheese-born E. faecalis strains by its antibiotics’ resistances and virulence genotype, thus its presence within the green cheese should not be considered as a health risk. Only two antibiotic resistance genetic determinants were found, but they both carry mutations, and probably are not functional. Furthermore, 18 virulence factor genetic determinants were found, but only 6 of them possessed 100% identities with the canonical sequences, and being more or less intrinsic for the Enterococcus genus. None of them were found on contigs that contain sequences with known plasmid origin of replication. Enterolysin A gene was also detected which...
Comparison of phenotypic and genotypic taxonomic methods for the identification of dairy enterococci
Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology, 2004
The purpose of the study was to assess the phenotypic and genotypic taxonomic congruence in order to allow species allocation of dairy enterococci. A total of 364 enterococci isolated from ewes'milk and cheese from four Portuguese Registered Designation of Origin areas and 25 type and reference strains of Enterococcus spp. were characterized by a polyphasic taxonomical approach involving 40 physiological and biochemical tests, whole-cell protein profiles, amplification of 16S-23S intergenic spacer regions (ITS-PCR) and subsequent restriction analysis (ARDRA). Ribotyping was also performed with reference strains and a subset of 146 isolates. Numerical hierarchic data analysis showed that single-technique identification levels increase from the physiological and biochemical tests to the protein approach, being lower with ITS/ARDRA and ribotyping. Cross-analysis confirmed a higher unmatching level in all pairwise combinations involving physiological and biochemical data. Whole-cell protein profiles followed by ITS/ARDRA identified 89% of the enterococci. Reliable identification of enterococci from milk and cheese could be obtained by analysis of whole-cell protein profiles. ITS-PCR can be used to confirm E. durans and E. faecium and ARDRA further confirms E. faecalis. Results revealed E. faecalis, E. durans, E. hirae and E. faecium as the prevalent species, although species prevalence showed some degree of variation among the areas.
Polyphasic characterization of Enterococcus strains isolated from traditional Moghan cheese in Iran
Journal of Food Safety, 2019
Traditional Moghan cheese is made from unpasteurized milk in the rural areas and nomadic tribes of Moghan region in Iran. In this study, we used a simple and rapid method for isolation of acid resistant lactic acid bacteria from traditional Moghan cheese. The six distinct isolates differentiated based on RAPD‐PCR were identified as members of Enterococcus faecium, E. faecalis, and E.durans species using classical phenotypic and biochemical tests as well as molecular methods. Based on the antibiotic susceptibility, the isolates were classified as resistant, intermediate, and sensitive. Cell‐free culture supernatants of isolates showed different antagonistic activity against the growth of some spoilage and food‐borne pathogens at two natural and neutralized pH conditions. Considering their tolerance to acid and bile, antagonistic effects on some spoilage and food‐borne pathogens and susceptibility to vancomycin, E. faecium strain ABRIINW.M (isolate IE2) and E. faecium strain ABRIINW.N...
Tarım Bilimleri Dergisi, 2022
Enterococcus faecium, E. durans and E. faecalis species were isolated and identified from traditional Urfa cheese samples which were produced from unpasteurized raw milk. The enterococcal load of the cheese samples was between 4.4-5.6 log cfu g−1. High-level tetracycline, streptomycin, erythromycin, gentamycin, and penicillin resistance was determined in the enterococcal isolates. Multiple antibiotic resistance was also determined in E. faecalis (20.4%) and E. faecium (16.3%) strains. 36.7% of the enterococcal isolates were greater than 0.2 MAR index ratio in this study. The gelE and agg2 genes were found in 40 (81.63%) of the enterococcal isolates, whereas the vanB gene was found in 3 (6.12%) of the enterococcal isolates. The results indicate that the consumption of Urfa cheese, which is produced using raw milk, may have public health risk because of its antibiotic resistance characteristics and virulence genes of enterococcal biota.
International journal of food microbiology, 2018
The members of the Enterococcus genus are widely distributed in nature. Its strains have been extensively reported to be present in plant surfaces, soil, water and food. In an attempt to assess their potential application in food industry, four Enterococcus faecium group-strains recently isolated from Argentinean regional cheese products were evaluated using a combination of whole genome analyses and in vivo assays. In order to identify these microorganisms at species level, in silico analyses using their newly reported sequences were conducted. The average nucleotide identity (ANI), in silico DNA-DNA hybridization, and phylogenomic trees constructed using core genome data allowed IQ110, GM70 and GM75 strains to be classified as E. faecium while IQ23 strain was identified as E. durans. Besides their common origin, the strains showed differences in their genetic structure and mobile genetic element content. Furthermore, it was possible to determine the absence or presence of specific...
Characterization and safety evaluation of enterococci isolated from Spanish goats' milk cheeses
International Journal of Food Microbiology, 2009
Enterococci are common constituents of dairy products such as cheese, in which it is believed that they contribute to the development of some of their organoleptic properties. This is particularly true in the Mediterranean region, where farmhouse cheeses are generally made from raw milk, which tends to harbour enterococci. In recent years, however, enterococci have emerged as serious pathogens in hospital environments, where vancomycin-resistant strains are on the increase. In this study we have characterized 95 enterococci isolated from 3 different goats' milk cheeses, belonging to the species Enterococcus devriesei, Enterococcus faecalis and E. malodoratus, among others. Genomic typification by RAPD and ERIC-PCR showed that the genotypes tended to be specific to particular cheeses; only two of the different cheeses contained two genotypes. E. malodoratus showed the highest intraspecific diversity. No more than 13% of the isolates demonstrated any antimicrobial activity, most of these belonging to E. devriesei. Screening for the most important enterocin structural genes by dot-blot hybridization proved negative for enterocins A, B and P. All the isolates belonging to E. faecalis, E. hirae and E. avium, on the other hand, hybridized with the enterocin EJ97 gene probe and all the E. faecalis strains hybridized with the AS-48 and MR10A structural gene probes. The genes gelE, esp, asa1, efaA and ace, all associated to virulence factors in enterococci, were detected at different levels in E. faecalis whilst they were not detected in the remaining species studied. No resistance to vancomycin was detected by PCR screening. The gene for tyrosine decarboxylase (tdc) was detected in all the E. faecalis and E. hirae isolates but in none of the others.
Strain typing among enterococci isolated from home-made Pecorino Sardo cheese
FEMS Microbiology Letters, 1999
Three molecular techniques (RAPD-polymerase chain reaction analysis, plasmid profile and pulsed-field gel electrophoresis) were used for a preliminary approach to type, at strain level, enterococci isolated from a 24-h-old home-made Pecorino Sardo (protected designation of origin) cheese. A high genetic polymorphism was found. Clusters obtained by the RAPD technique and plasmid profile analysis contained different strains. Pulsed-field gel electrophoresis proved to be an efficient and highly reproducible typing method. In addition, by combining the results from plasmid profile analysis and pulsed-field gel electrophoresis, it was possible to identify closely related strains probably belonging to the same clonal lineage. z 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.