Phenotypic and genotypic heterogeneity of Enterococcus species isolated from food in Southern Brazil.
Enterococcus is an important group of lactic acid bacteria (LAB), which inhabits the gastrointestinal tract of humans and animals. These microorganisms can also be found in large groups of foods where they can play a beneficial role during food maturation processes or, conversely, can be used as a food contamination indicator. These microorganisms have an additional importance in various aspects of clinical microbiology. The aim of this study was to investigate and determine the phenotypic and genetic diversity in 55 enterococci isolated from different food sources. Phenotypic characteristics based upon substrate hydrolysis differences were used to identify different Enterococcus species. Analysis of the resultant data divided these species into eight Enterococcus phenotype groups. E. faecalis was the food isolate species with the greatest phenotypic variability. Fifty-five previously isolated Enterococcus strains were re-confirmed as belonging to this genus by PCR techniques. Randomly amplified polymorphic DNA (RAPD-PCR) was used to study the genetic variability using M13 primers and the resultant DNA fragments produced a database of different fingerprints. After statistical analyses of the RAPD-PCR profiles, 42 patterns were obtained and 6 different Enterococcus RAPD clusters (ERC) were identified. Genetic diversity was highest in ERC I, which grouped together approximately 40% of the E. faecium and E. faecalis isolates obtained from dairy products. Samples isolated from meat and vegetables offered the greatest genotype variability. Results of the present study suggest the presence of both phenotypic and genotypic variability within enterococci strains isolated from diverse sources of food common to Southern Brazil.
Pelicioli Riboldi
Gustavo
G
Programa de Pós-Graduação em Biologia Celular e Molecular, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul.
Preusser de Mattos
Eduardo
E
Guedes Frazzon
Ana Paula
AP
Alves d'Azevedo
Pedro
P
Frazzon
Jeverson
J
D000818:Animals; D015373:Bacterial Typing Techniques; D001938:Brazil; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D016983:Enterococcus / Q000145:classification* / Q000302:isolation & purification* / Q000378:metabolism; D005516:Food Microbiology; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D019105:Random Amplified Polymorphic DNA Technique
D004269:DNA, Bacterial