title: Phylogenetic, epidemiological and functional analyses of the Streptococcus bovis/Streptococcus equinus complex through an overarching MLST scheme.
abstract: The Streptococcus bovis/Streptococcus equinus complex (SBSEC) comprises seven (sub)species classified as human and animal commensals, emerging opportunistic pathogens and food fermentative organisms. Changing taxonomy, shared habitats, natural competence and evidence for horizontal gene transfer pose difficulties for determining their phylogeny, epidemiology and virulence mechanisms. Thus, novel phylogenetic and functional classifications are required. An SBSEC overarching multi locus sequence type (MLST) scheme targeting 10 housekeeping genes was developed, validated and combined with host-related properties of adhesion to extracellular matrix proteins (ECM), activation of the immune responses via NF-KB and survival in simulated gastric juice (SGJ).
  
  
  
  Commensal and pathogenic SBSEC strains (n = 74) of human, animal and food origin from Europe, Asia, America and Africa were used in the MLST scheme yielding 66 sequence types and 10 clonal complexes differentiated into distinct habitat-associated and mixed lineages. Adhesion to ECMs collagen I and mucin type II was a common characteristic (23 % of strains) followed by adhesion to fibronectin and fibrinogen (19.7 %). High adhesion abilities were found for East African dairy and human blood isolate branches whereas commensal fecal SBSEC displayed low adhesion. NF-KB activation was observed for a limited number of dairy and blood isolates suggesting the potential of some pathogenic strains for reduced immune activation. Strains from dairy MLST clades displayed the highest relative survival to SGJ independently of dairy adaptation markers lacS/lacZ.
  
  
  
  Combining phylogenetic and functional analyses via SBSEC MLST enabled the clear delineation of strain clades to unravel the complexity of this bacterial group. High adhesion values shared between certain dairy and blood strains as well as the behavior of NF-KB activation are concerning for specific lineages. They highlighted the health risk among shared lineages and establish the basis to elucidate (zoonotic-) transmission, host specificity, virulence mechanisms and enhanced risk assessment as pathobionts in an overarching One Health approach.
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Jans
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
authors.forename: Tomas
authors.initials: T
authors.lastname: de Wouters
authors.affiliation: Centre Suisse de Recherches Scientifiques en Côte d'Ivoire (CSRS), KM 17 route de Dabou, Adiopodoumé Yopougon, Abidjan - 01B.P. 1303, Abidjan, Côte d'Ivoire.
authors.forename: Bassirou
authors.initials: B
authors.lastname: Bonfoh
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Lacroix
authors.affiliation: Department of Food Science, Nutrition and Technology, College of Agriculture and Veterinary Sciences, University of Nairobi, P.O. Box 29053, Nairobi, Kenya.
authors.forename: Dasel Wambua Mulwa
authors.initials: DW
authors.lastname: Kaindi
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
authors.forename: Janine
authors.initials: J
authors.lastname: Anderegg
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
authors.forename: Désirée
authors.initials: D
authors.lastname: Böck
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Vitali
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmid
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
authors.forename: Julia
authors.initials: J
authors.lastname: Isenring
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Kurt
authors.affiliation: Department of Food Science, Nutrition and Technology, College of Agriculture and Veterinary Sciences, University of Nairobi, P.O. Box 29053, Nairobi, Kenya.
authors.forename: Wambui
authors.initials: W
authors.lastname: Kogi-Makau
authors.affiliation: Laboratory of Food Biotechnology, Institute of Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, 8092, Zurich, Switzerland. leo.meile@hest.ethz.ch.
authors.forename: Leo
authors.initials: L
authors.lastname: Meile
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001483:Base Sequence; D018834:Chaperonin 60 / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D005750:Gastric Juice / Q000382:microbiology; D020043:Genes, Essential; D006801:Humans; D058885:Multilocus Sequence Typing / Q000379:methods; D016328:NF-kappa B / Q000276:immunology; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013290:Streptococcal Infections / Q000097:blood / Q000453:epidemiology* / Q000382:microbiology; D013291:Streptococcus / Q000235:genetics* / Q000302:isolation & purification*; D016985:Streptococcus bovis / Q000235:genetics / Q000302:isolation & purification; D000070099:Streptococcus gallolyticus / Q000235:genetics / Q000302:isolation & purification
chemical_list: D018834:Chaperonin 60; D004269:DNA, Bacterial; D016328:NF-kappa B; D012336:RNA, Ribosomal, 16S
keywords: Adhesion; Colorectal cancer; Foodborne disease; Infective endocarditis; Inflammation; One health; Pathobiont; Streptococcus gallolyticus; Streptococcus infantarius; Streptococcus macedonicus