Exploring Beneficial/Virulence Properties of Two Dairy-Related Strains of Streptococcus infantarius subsp. infantarius
- PDF / 773,374 Bytes
- 18 Pages / 595.276 x 790.866 pts Page_size
- 104 Downloads / 170 Views
Exploring Beneficial/Virulence Properties of Two Dairy-Related Strains of Streptococcus infantarius subsp. infantarius Karina Maria Olbrich dos Santos 1,2 & Carliane Ribeiro de Matos 2 & Hévila Oliveira Salles 2 & Bernadette Dora Gombossy de Melo Franco 3 & Karina Arellano 4 & Wilhelm Heinrich Holzapfel 4 & Svetoslav Dimitrov Todorov 3,4
# Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract The genus Streptococcus includes various species, remarkably different in their behavior, applications, virulence, and safety. Taxonomically Streptococcus infantarius subsp. infantarius belonging to the Streptococcus bovis group, which includes several pathogen species, however, has been found as predominant species in some African dairy products that are widely consumed and considered to be safe. Streptococcus infantarius subsp. infantarius’ safety may be questioned due to the association of this species with clinical cases. In this study, isolates from dairy origin were selected based on their bacteriocinogenic potential and differentiated by their RAPD-PCR profiles. Two strains were identified by 16S rRNA sequencing as St. infantarius subsp. infantarius and investigated regarding their potential beneficial properties and factors related to virulence and safety. A series of in vitro tests included properties related to survival in the gastrointestinal tract and beneficial intestinal activities. Production of bacteriocin/s, detection of related genes, and partial characterization of expressed antimicrobial protein were evaluated. Genes related to folate biosynthesis were detected in both studied strains. Evaluation of physiological tests related to strains virulence, adhesion, and resistance to antibiotics and detections of virulence and biogenic amines production-related genes were also investigated. Taking in consideration all the aspects of the specific nature of St. infantarius subsp. infantarius K1–4 and K5–1 (beneficial properties and virulence characteristics), both strains cannot be considered safe for human or other animals application, even though they have been isolated from dairy products. This study is highlighting the importance of evaluation for presence of potential virulence factors in newly characterized strains in order to be confident in their safety. Keywords Streptococcus infantarius subsp. infantarius . Bacteriocins . Folate . Virulence . Antibiotic resistance . Safety . Gastrointestinal tract . Probiotics
Introduction Since establishment of microbiology as a part of the family of biological sciences, the isolation, identification, and characterization of new species have gradually developed to a “normal” * Svetoslav Dimitrov Todorov [email protected] 1
EMBRAPA Agroindustria de Alimentos, Rio de Janeiro, RJ, Brazil
2
EMBRAPA Caprinos e Ovinos, Sobral, CE, Brazil
3
Departamento de Alimentos e Nutrição Experimental, Laboratório de Microbiologia de Alimentos, Universidade de São Paulo, Faculdade de Ciências Farmacêuticas, São Paulo, SP, Brazil
4
Advanced Green Energy and En
Data Loading...
