The Experts below are selected from a list of 426 Experts worldwide ranked by ideXlab platform

Konstantinos Papadimitriou - One of the best experts on this subject based on the ideXlab platform.

Pierre Renault - One of the best experts on this subject based on the ideXlab platform.

  • Colorectal cancer-associated Streptococcus infantarius subsp. infantarius differ from a major dairy lineage providing evidence for pathogenic, pathobiont and food-grade lineages
    Scientific Reports, 2018
    Co-Authors: Dasel W M Kaindi, Leo Meile, Pierre Renault, Bernd Kreikemeyer, Nize Otaru, Wambui Kogi-makau, Godfrey N. Lule, Bassirou Bonfoh, Thomas Schmid, Jan Hattendorf
    Abstract:

    Streptococcus infantarius subsp. infantarius (Sii), a member of the Streptococcus bovis/Streptococcus equinus complex (SBSEC), predominates as dairy-adapted and non-adapted variants in fermented dairy products (FDP) in East and West Africa. Epidemiologic data suggest an association with colorectal cancer for most SBSEC members, including Sii from Kenyan patients. Phylogenetic relationships of East African human (EAH) isolates to those of dairy and pathogenic origin were analysed to better estimate potential health implications via FDP consumption. The MLST-derived population structure was also evaluated to provide host, disease, geography and dairy adaptation associations for 157 SBSEC isolates, including 83 novel Sii/SBSEC isolates of which 40 originated from Kenyan colonoscopy patients. Clonal complex (CC) 90 was delineated as potential pathogenic CC for Sii. Single EAH, West African dairy (WAD), food and animal Sii isolates clustered within CC-90, suggesting a potential link to pathogenic traits for CC-90. The majority of EAH and WAD Sii were clustered in a shared clade distinct from CC-90 and East African dairy (EAD) isolates. This indicates shared ancestry for the EAH and WAD clade and limitations to translate disease associations of EAH and CC-90 to EAD Sii, which could support the separation of pathogenic, pathobiont/commensal and food lineages.

  • Investigating the association between African spontaneously fermented dairy products, faecal carriage of Streptococcus infantarius subsp. infantarius and colorectal adenocarcinoma in Kenya
    Acta Tropica, 2018
    Co-Authors: Dasel W M Kaindi, Christophe Lacroix, Pierre Renault, Bernd Kreikemeyer, Wambui Kogi-makau, Godfrey N. Lule, Bassirou Bonfoh, Esther Schelling, Jakob Zinsstag, Leo Meile
    Abstract:

    Consumption of traditional fermented dairy products (tFDP) in Africa leads to the ingestion of up to 10(8) Streptococcus infantarius subspecies infantarius (Sii) per millilitre of spontaneously fermented milk Sii is a member of the Streptococcus bovis/Streptococcus equinus complex (SBSEC) for which some members are associated particularly with colorectal cancer or endocarditis. The extent of health risks to tFDP consumers is largely unknown. A hospital-based unmatched case-control study was conducted at Kenyatta National Hospital, Nairobi (Kenya) on 80 cases and 193 controls that were selected exhaustively from patients attending colonoscopy at the hospital. Logistic regression models adjusted for age, sex and residency were used in the statistical analysis. Consumption of tFDP was not associated with CRC (odds ratio (OR) 1.4; 95% Confidence interval (CI) 0.7-2.7; p = 0.34). Risk factors associated with CRC included age above 40 years, and consumption of processed meat and alcohol. Faecal carriage of Sii was significantly higher in persons with colon tumours and polyps compared to controls (8.4% vs 21.6%: OR: 4.6; CI 1.3-15.9). Patients with haemorrhoids represented an unexpected carrier group with significantly higher Sii faecal carriage (30.4%, CI: 17.7-45.8). Consumption of tFDP does not represent risk factors for CRC whereas Sii seems to be associated with CRC. However, there is urgent need to assess this finding also in the general population, investigate the causality of SBSEC, Sii and CRC as well as compare the phylogenetic, functional and genomic relationship between human and dairy Sii with regards to the ongoing application of Sii in FDP production.

  • RESEARCH ARTICLE Acquisition through Horizontal Gene Transfer of Plasmid pSMA198 by Streptococcus macedonicus ACA-DC 198 Points towards the Dairy Origin of the Species
    2016
    Co-Authors: Konstantinos Papadimitriou, Pierre Renault, Rania Anastasiou, Stavros J Hamodrakas, Stephanie Ferreira, Bruno Pot, Eleni Maistrou, Thomas Plakas, Nikos C. Pap, Effie Tsakalidou
    Abstract:

    Background Streptococcus macedonicus is an intriguing streptococcal species whose most frequent source of isolation is fermented foods similarly to Streptococcus thermophilus. However, S. macedonicus is closely related to commensal opportunistic pathogens of the Streptococcus bovis/Streptococcus equinus complex. Methodology/Principal Findings We analyzed the pSMA198 plasmid isolated from the dairy strain Streptococcus macedonicus ACA-DC 198 in order to provide novel clues about the main ecological niche of this bacterium. pSMA198 belongs to the narrow host range pCI305/pWV02 family found primarily in lactococci and to the best of our knowledge it is the first such plasmid to be re-ported in streptococci. Comparative analysis of the pSMA198 sequence revealed a high degree of similarity with plasmids isolated from Lactococcus lactis strains deriving from milk or its products. Phylogenetic analysis of the pSMA198 Rep showed that the vast majority of closely related proteins derive from lactococcal dairy isolates. Additionally, cloning of th

  • Acquisition through horizontal gene transfer of plasmid pSMA198 by [i]Streptococcus macedonicus[/i] ACA-DC 198 points towards the dairy origin of the species
    PLoS ONE, 2015
    Co-Authors: Konstantinos Papadimitriou, Pierre Renault, Rania Anastasiou, Nikos C Papandreou, Stavros J Hamodrakas, Stephanie Ferreira, Philip Supply, Eleni Maistrou, Thomas Plakas, Bruno Pot
    Abstract:

    Background Streptococcus macedonicus is an intriguing streptococcal species whose most frequent source of isolation is fermented foods similarly to Streptococcus thermophilus. However, S. macedonicus is closely related to commensal opportunistic pathogens of the Streptococcus bovis/Streptococcus equinus complex. Methodology/Principal Findings We analyzed the pSMA198 plasmid isolated from the dairy strain Streptococcus macedonicus ACA-DC 198 in order to provide novel clues about the main ecological niche of this bacterium. pSMA198 belongs to the narrow host range pCI305/pWV02 family found primarily in lactococci and to the best of our knowledge it is the first such plasmid to be reported in streptococci. Comparative analysis of the pSMA198 sequence revealed a high degree of similarity with plasmids isolated from Lactococcus lactis strains deriving from milk or its products. Phylogenetic analysis of the pSMA198 Rep showed that the vast majority of closely related proteins derive from lactococcal dairy isolates. Additionally, cloning of the pSMA198 ori in L. lactis revealed a 100% stability of replication over 100 generations. Both pSMA198 and the chromosome of S. macedonicus exhibit a high percentage of potential pseudogenes, indicating that they have co-evolved under the same gene decay processes. We identified chromosomal regions in S. macedonicus that may have originated from pSMA198, also supporting a long co-existence of the two replicons. pSMA198 was also found in divergent biotypes of S. macedonicus and in strains isolated from dispersed geographic locations (e.g. Greece and Switzerland) showing that pSMA198's acquisition is not a recent event. Conclusions/Significance Here we propose that S. macedonicus acquired plasmid pSMA198 from L. lactis via an ancestral genetic exchange event that took place most probably in milk or dairy products. We provide important evidence that point towards the dairy origin of this species.

  • comparative genomics of the dairy isolate Streptococcus macedonicus aca dc 198 against related members of the Streptococcus bovis Streptococcus equinus complex
    BMC Genomics, 2014
    Co-Authors: Konstantinos Papadimitriou, Pierre Renault, Rania Anastasiou, Eleni Mavrogonatou, Jochen Blom, Nikos C Papandreou, Stavros J Hamodrakas, Stephanie Ferreira, Philip Supply
    Abstract:

    Background Within the genus Streptococcus, only Streptococcus thermophilus is used as a starter culture in food fermentations. Streptococcus macedonicus though, which belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC), is also frequently isolated from fermented foods mainly of dairy origin. Members of the SBSEC have been implicated in human endocarditis and colon cancer. Here we compare the genome sequence of the dairy isolate S. macedonicus ACA-DC 198 to the other SBSEC genomes in order to assess in silico its potential adaptation to milk and its pathogenicity status.

Christoph Jans - One of the best experts on this subject based on the ideXlab platform.

  • DataSheet1.XLSX
    2018
    Co-Authors: Christoph Jans, Annemarie Boleij
    Abstract:

    The Streptococcus bovis/Streptococcus equinus complex (SBSEC) comprises several species inhabiting the animal and human gastrointestinal tract (GIT). They match the pathobiont description, are potential zoonotic agents and technological organisms in fermented foods. SBSEC members are associated with multiple diseases in humans and animals including ruminal acidosis, infective endocarditis (IE) and colorectal cancer (CRC). Therefore, this review aims to re-evaluate adhesion and colonization abilities of SBSEC members of animal, human and food origin paired with genomic and functional host-microbe interaction data on their road from colonization to infection. SBSEC seem to be a marginal population during GIT symbiosis that can proliferate as opportunistic pathogens. Risk factors for human colonization are considered living in rural areas and animal-feces contact. Niche adaptation plays a pivotal role where Streptococcus gallolyticus subsp. gallolyticus (SGG) retained the ability to proliferate in various environments. Other SBSEC members have undergone genome reduction and niche-specific gene gain to yield important commensal, pathobiont and technological species. Selective colonization of CRC tissue is suggested for SGG, possibly related to increased adhesion to cancerous cell types featuring enhanced collagen IV accessibility. SGG can colonize, proliferate and may shape the tumor microenvironment to their benefit by tumor promotion upon initial neoplasia development. Bacteria cell surface structures including lipotheichoic acids, capsular polysaccharides and pilus loci (pil1, pil2, and pil3) govern adhesion. Only human blood-derived SGG contain complete pilus loci and other disease-associated surface proteins. Rumen or feces-derived SGG and other SBSEC members lack or harbor mutated pili. Pili also contribute to binding to fibrinogen upon invasion and translocation of cells from the GIT into the blood system, subsequent immune evasion, human contact system activation and collagen-I-binding on damaged heart valves. Only SGG carrying complete pilus loci seem to have highest IE potential in humans with significant links between SGG bacteremia/IE and underlying diseases including CRC. Other SBSEC host-microbe combinations might rely on currently unknown mechanisms. Comparative genome data of blood, commensal and food isolates are limited but required to elucidate the role of pili and other virulence factors, understand pathogenicity mechanisms, host specificity and estimate health risks for animals, humans and food alike.

  • the road to infection host microbe interactions defining the pathogenicity of Streptococcus bovis Streptococcus equinus complex members
    Frontiers in Microbiology, 2018
    Co-Authors: Christoph Jans, Annemarie Boleij
    Abstract:

    The Streptococcus bovis/Streptococcus equinus complex (SBSEC) comprises several species inhabiting the animal and human gastrointestinal tract (GIT). They match the pathobiont description, are potential zoonotic agents and technological organisms in fermented foods. SBSEC members are associated with multiple diseases in humans and animals including ruminal acidosis, infective endocarditis (IE) and colorectal cancer (CRC). Therefore, this review aims to re-evaluate adhesion and colonization abilities of SBSEC members of animal, human and food origin paired with genomic and functional host-microbe interaction data on their road from colonization to infection. SBSEC seem to be a marginal population during GIT symbiosis that can proliferate as opportunistic pathogens. Risk factors for human colonization are considered living in rural areas and animal-feces contact. Niche adaptation plays a pivotal role where Streptococcus gallolyticus subsp. gallolyticus (SGG) retained the ability to proliferate in various environments. Other SBSEC members have undergone genome reduction and niche-specific gene gain to yield important commensal, pathobiont and technological species. Selective colonization of CRC tissue is suggested for SGG, possibly related to increased adhesion to cancerous cell types featuring enhanced collagen IV accessibility. SGG can colonize, proliferate and may shape the tumor microenvironment to their benefit by tumor promotion upon initial neoplasia development. Bacteria cell surface structures including lipotheichoic acids, capsular polysaccharides and pilus loci (pil1, pil2, and pil3) govern adhesion. Only human blood-derived SGG contain complete pilus loci and other disease-associated surface proteins. Rumen or feces-derived SGG and other SBSEC members lack or harbor mutated pili. Pili also contribute to binding to fibrinogen upon invasion and translocation of cells from the GIT into the blood system, subsequent immune evasion, human contact system activation and collagen-I-binding on damaged heart valves. Only SGG carrying complete pilus loci seem to have highest IE potential in humans with significant links between SGG bacteremia/IE and underlying diseases including CRC. Other SBSEC host-microbe combinations might rely on currently unknown mechanisms. Comparative genome data of blood, commensal and food isolates are limited but required to elucidate the role of pili and other virulence factors, understand pathogenicity mechanisms, host specificity and estimate health risks for animals, humans and food alike.

  • Complete Genome Sequence of the African Dairy Isolate Streptococcus infantarius subsp. infantarius Strain CJ18
    2016
    Co-Authors: Christoph Jans, Christophe Lacroix, Leo Meile, Rainer Follador, Marc J A Stevens
    Abstract:

    Streptococcus infantarius subsp. infantarius, a member of the Streptococcus bovis/Streptococcus equinus complex, is highly prevalent in artisanal dairy fermentations in Africa. Here the complete genome sequence of the dairy-adapted S. infan-tarius subsp. infantarius CJ18 strain—a strain predominant in traditionally fermented camel milk (suusac) from Kenya—is presented. Streptococcus infantarius subsp. infantarius and other membersof the Streptococcus bovis/Streptococcus equinus complex (SBSEC) are increasingly isolated from traditionally fermented dairy andplant products in Europe,Mexico, andAfrica (1, 3, 6, 10, 12). Particularly in Africa, S. infantarius subsp. infantarius seems to play a pivotal role in spontaneous dairy fermentations, being present at up to 108 CFU per ml in the end product (6). Members of the SBSEC are associated with various human and animal in-fections (4, 9). Therefore, ingestion of large quantities of live cells of S. infantarius subsp. infantarius may hold a potential health risk. S. infantarius subsp. infantarius strain CJ18 was isolated from spontaneously fermented Kenyan camel milk (suusac) (6). Inter

  • phylogenetic epidemiological and functional analyses of the Streptococcus bovis Streptococcus equinus complex through an overarching mlst scheme
    BMC Microbiology, 2016
    Co-Authors: Christoph Jans, Christophe Lacroix, Dasel W M Kaindi, Bassirou Bonfoh, Desiree Bock, Tomas De Wouters, Janine Anderegg, Sabrina Vitali, Thomas Schmid, Julia Isenring
    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.

  • additional file 12 of phylogenetic epidemiological and functional analyses of the Streptococcus bovis Streptococcus equinus complex through an overarching mlst scheme
    2016
    Co-Authors: Christoph Jans, Christophe Lacroix, Dasel W M Kaindi, Bassirou Bonfoh, Tomas De Wouters, Janine Anderegg, Sabrina Vitali, Thomas Schmid, Dăssirăse Băśck, Julia Isenring
    Abstract:

    Title of data: Relative survival of SBSEC members under simulated gastric conditions at pH 3.0. Description of data: Relative survival of SBSEC strains at 5, 10 and 15 min in in simulated gastric conditions at pH 3.0 performed in 2 biological replications. Input of 0 log10 CFU mL−1 was used as basis from which relative survival is expressed. Relative survival values were normalized to allow comparison between strains where positive values indicate relative survival higher than the mean of all strains. Statistical distribution indicators: Median: large black dotted line; Q1 and Q3: small black dotted line; lower and upper outlier fence: large yellow dotted line (only drawn if within the graph range displayed). The phylogenetic tree is based on the MLST-tree but not drawn to scale. (TIF 3007 kb)

Leo Meile - One of the best experts on this subject based on the ideXlab platform.

  • Investigating the association between African spontaneously fermented dairy products, faecal carriage of Streptococcus infantarius subsp. infantarius and colorectal adenocarcinoma in Kenya
    Acta Tropica, 2018
    Co-Authors: Dasel W M Kaindi, Christophe Lacroix, Pierre Renault, Bernd Kreikemeyer, Wambui Kogi-makau, Godfrey N. Lule, Bassirou Bonfoh, Esther Schelling, Jakob Zinsstag, Leo Meile
    Abstract:

    Consumption of traditional fermented dairy products (tFDP) in Africa leads to the ingestion of up to 10(8) Streptococcus infantarius subspecies infantarius (Sii) per millilitre of spontaneously fermented milk Sii is a member of the Streptococcus bovis/Streptococcus equinus complex (SBSEC) for which some members are associated particularly with colorectal cancer or endocarditis. The extent of health risks to tFDP consumers is largely unknown. A hospital-based unmatched case-control study was conducted at Kenyatta National Hospital, Nairobi (Kenya) on 80 cases and 193 controls that were selected exhaustively from patients attending colonoscopy at the hospital. Logistic regression models adjusted for age, sex and residency were used in the statistical analysis. Consumption of tFDP was not associated with CRC (odds ratio (OR) 1.4; 95% Confidence interval (CI) 0.7-2.7; p = 0.34). Risk factors associated with CRC included age above 40 years, and consumption of processed meat and alcohol. Faecal carriage of Sii was significantly higher in persons with colon tumours and polyps compared to controls (8.4% vs 21.6%: OR: 4.6; CI 1.3-15.9). Patients with haemorrhoids represented an unexpected carrier group with significantly higher Sii faecal carriage (30.4%, CI: 17.7-45.8). Consumption of tFDP does not represent risk factors for CRC whereas Sii seems to be associated with CRC. However, there is urgent need to assess this finding also in the general population, investigate the causality of SBSEC, Sii and CRC as well as compare the phylogenetic, functional and genomic relationship between human and dairy Sii with regards to the ongoing application of Sii in FDP production.

  • Colorectal cancer-associated Streptococcus infantarius subsp. infantarius differ from a major dairy lineage providing evidence for pathogenic, pathobiont and food-grade lineages
    Scientific Reports, 2018
    Co-Authors: Dasel W M Kaindi, Leo Meile, Pierre Renault, Bernd Kreikemeyer, Nize Otaru, Wambui Kogi-makau, Godfrey N. Lule, Bassirou Bonfoh, Thomas Schmid, Jan Hattendorf
    Abstract:

    Streptococcus infantarius subsp. infantarius (Sii), a member of the Streptococcus bovis/Streptococcus equinus complex (SBSEC), predominates as dairy-adapted and non-adapted variants in fermented dairy products (FDP) in East and West Africa. Epidemiologic data suggest an association with colorectal cancer for most SBSEC members, including Sii from Kenyan patients. Phylogenetic relationships of East African human (EAH) isolates to those of dairy and pathogenic origin were analysed to better estimate potential health implications via FDP consumption. The MLST-derived population structure was also evaluated to provide host, disease, geography and dairy adaptation associations for 157 SBSEC isolates, including 83 novel Sii/SBSEC isolates of which 40 originated from Kenyan colonoscopy patients. Clonal complex (CC) 90 was delineated as potential pathogenic CC for Sii. Single EAH, West African dairy (WAD), food and animal Sii isolates clustered within CC-90, suggesting a potential link to pathogenic traits for CC-90. The majority of EAH and WAD Sii were clustered in a shared clade distinct from CC-90 and East African dairy (EAD) isolates. This indicates shared ancestry for the EAH and WAD clade and limitations to translate disease associations of EAH and CC-90 to EAD Sii, which could support the separation of pathogenic, pathobiont/commensal and food lineages.

  • Complete Genome Sequence of the African Dairy Isolate Streptococcus infantarius subsp. infantarius Strain CJ18
    2016
    Co-Authors: Christoph Jans, Christophe Lacroix, Leo Meile, Rainer Follador, Marc J A Stevens
    Abstract:

    Streptococcus infantarius subsp. infantarius, a member of the Streptococcus bovis/Streptococcus equinus complex, is highly prevalent in artisanal dairy fermentations in Africa. Here the complete genome sequence of the dairy-adapted S. infan-tarius subsp. infantarius CJ18 strain—a strain predominant in traditionally fermented camel milk (suusac) from Kenya—is presented. Streptococcus infantarius subsp. infantarius and other membersof the Streptococcus bovis/Streptococcus equinus complex (SBSEC) are increasingly isolated from traditionally fermented dairy andplant products in Europe,Mexico, andAfrica (1, 3, 6, 10, 12). Particularly in Africa, S. infantarius subsp. infantarius seems to play a pivotal role in spontaneous dairy fermentations, being present at up to 108 CFU per ml in the end product (6). Members of the SBSEC are associated with various human and animal in-fections (4, 9). Therefore, ingestion of large quantities of live cells of S. infantarius subsp. infantarius may hold a potential health risk. S. infantarius subsp. infantarius strain CJ18 was isolated from spontaneously fermented Kenyan camel milk (suusac) (6). Inter

  • genomics evolution and molecular epidemiology of the Streptococcus bovis Streptococcus equinus complex sbsec
    Infection Genetics and Evolution, 2015
    Co-Authors: Christoph Jans, Christophe Lacroix, Leo Meile, Marc J A Stevens
    Abstract:

    The Streptococcus bovis/Streptococcus equinus complex (SBSEC) is a group of human and animal derived streptococci that are commensals (rumen and gastrointestinal tract), opportunistic pathogens or food fermentation associates. The classification of SBSEC has undergone massive changes and currently comprises 7 (sub)species grouped into four branches based on sequences identities: the Streptococcus gallolyticus, the Streptococcus equinus, the Streptococcus infantarius and the Streptococcus alactolyticus branch. In animals, SBSEC are causative agents for ruminal acidosis, potentially laminitis and infective endocarditis (IE). In humans, a strong association was established between bacteraemia, IE and colorectal cancer. Especially the SBSEC-species S. gallolyticus subsp. gallolyticus is an emerging pathogen for IE and prosthetic joint infections. S. gallolyticus subsp. pasteurianus and the S. infantarius branch are further associated with biliary and urinary tract infections. Knowledge on pathogenic mechanisms is so far limited to colonization factors such as pili and biofilm formation. Certain strain variants of S. gallolyticus subsp. macedonicus and S. infantarius subsp. infantarius are associated with traditional dairy and plant-based food fermentations and display traits suggesting safety. However, due to their close relationship to virulent strains, their use in food fermentation has to be critically assessed. Additionally, implementing accurate and up-to-date taxonomy is critical to enable appropriate treatment of patients and risk assessment of species and strains via recently developed multilocus sequence typing schemes to enable comparative global epidemiology. Comparative genomics revealed that SBSEC strains harbour genomics islands (GI) that seem acquired from other streptococci by horizontal gene transfer. In case of virulent strains these GI frequently encode putative virulence factors, in strains from food fermentation the GI encode functions that are pivotal for strain performance during fermentation. Comparative genomics is a powerful tool to identify acquired pathogenic functions, but there is still an urgent need for more physiological and epidemiological data to understand SBSEC-specific traits.

  • prevalence and comparison of Streptococcus infantarius subsp infantarius and Streptococcus gallolyticus subsp macedonicus in raw and fermented dairy products from east and west africa
    International Journal of Food Microbiology, 2013
    Co-Authors: Christoph Jans, Christophe Lacroix, Dasel W M Kaindi, Bassirou Bonfoh, Desiree Bock, Patrick Murigu Kamau Njage, Sylvie Mireille Kouamesina, Leo Meile
    Abstract:

    Streptococcus infantarius subsp. infantarius (Sii) and Streptococcus gallolyticus subsp. macedonicus are members of the Streptococcus bovis/Streptococcus equinus complex (SBSEC) associated with human infections. SBSEC-related endocarditis was furthermore associated with rural residency in Southern Europe. SBSEC members are increasingly isolated as predominant species from fermented dairy products in Europe, Asia and Africa. African variants of Sii displayed dairy adaptations to lactose metabolism paralleling those of Streptococcus thermophilus including genome decay. In this study, the aim was to assess the prevalence of Sii and possibly other SBSEC members in dairy products of East and West Africa in order to identify their habitat, estimate their importance in dairy fermentation processes and determine geographic areas affected by this potential health risk. Presumptive SBSEC members were isolated on semi-selective M17 and SM agar media. Subsequent genotypic identification of isolates was based on rep-PCR fingerprinting and SBSEC-specific16S rRNA gene PCR assay. Detailed identification was achieved through application of novel primers enhancing the binding stringency in partial groES/groEL gene amplification and subsequent DNA sequencing. The presence of S. thermophilus-like lacS and lacZ genes in the SBSEC isolates was determined to elucidate the prevalence of this dairy adaptation. Isolates (n = 754) were obtained from 72 raw and 95 fermented milk samples from Cote d'Ivoire and Kenya on semi-selective agar media. Colonies of Sii were not detected from raw milk despite high microbial titers of approximately 106 CFU/mL on M17 agar medium. However, after spontaneous milk fermentation Sii was genotypically identified in 94.1% of Kenyan samples and 60.8% of Kenyan isolates. Sii prevalence in Cote d'Ivoire displayed seasonal variations in samples from 32.3% (June) to 40.0% (Dec/Jan) and isolates from 20.5% (June) to 27.7% (Dec/Jan) present at titers of 106–108 CFU/mL. lacS and lacZ genes were detected in all Kenyan and 25.8% (June) to 65.4% (Dec/Jan) of Ivorian Sii isolates. Regional differences in prevalence of Sii and dairy adaptations were observed, but no clear effect of dairy animal, fermentation procedure and climate was revealed. Conclusively, the high prevalence of Sii in Kenya, Cote d'Ivoire in addition to Somalia, Sudan and Mali strongly indicates a pivotal role of Sii in traditional African dairy fermentations potentially paralleling that of typical western dairy species S. thermophilus. Putative health risks associated with the consumption of high amounts of live Sii and potential different degrees of evolutionary adaptation or ecological colonization require further epidemiologic and genomic investigations, particularly in Africa.

Philip Supply - One of the best experts on this subject based on the ideXlab platform.

  • Acquisition through horizontal gene transfer of plasmid pSMA198 by [i]Streptococcus macedonicus[/i] ACA-DC 198 points towards the dairy origin of the species
    PLoS ONE, 2015
    Co-Authors: Konstantinos Papadimitriou, Pierre Renault, Rania Anastasiou, Nikos C Papandreou, Stavros J Hamodrakas, Stephanie Ferreira, Philip Supply, Eleni Maistrou, Thomas Plakas, Bruno Pot
    Abstract:

    Background Streptococcus macedonicus is an intriguing streptococcal species whose most frequent source of isolation is fermented foods similarly to Streptococcus thermophilus. However, S. macedonicus is closely related to commensal opportunistic pathogens of the Streptococcus bovis/Streptococcus equinus complex. Methodology/Principal Findings We analyzed the pSMA198 plasmid isolated from the dairy strain Streptococcus macedonicus ACA-DC 198 in order to provide novel clues about the main ecological niche of this bacterium. pSMA198 belongs to the narrow host range pCI305/pWV02 family found primarily in lactococci and to the best of our knowledge it is the first such plasmid to be reported in streptococci. Comparative analysis of the pSMA198 sequence revealed a high degree of similarity with plasmids isolated from Lactococcus lactis strains deriving from milk or its products. Phylogenetic analysis of the pSMA198 Rep showed that the vast majority of closely related proteins derive from lactococcal dairy isolates. Additionally, cloning of the pSMA198 ori in L. lactis revealed a 100% stability of replication over 100 generations. Both pSMA198 and the chromosome of S. macedonicus exhibit a high percentage of potential pseudogenes, indicating that they have co-evolved under the same gene decay processes. We identified chromosomal regions in S. macedonicus that may have originated from pSMA198, also supporting a long co-existence of the two replicons. pSMA198 was also found in divergent biotypes of S. macedonicus and in strains isolated from dispersed geographic locations (e.g. Greece and Switzerland) showing that pSMA198's acquisition is not a recent event. Conclusions/Significance Here we propose that S. macedonicus acquired plasmid pSMA198 from L. lactis via an ancestral genetic exchange event that took place most probably in milk or dairy products. We provide important evidence that point towards the dairy origin of this species.

  • comparative genomics of the dairy isolate Streptococcus macedonicus aca dc 198 against related members of the Streptococcus bovis Streptococcus equinus complex
    BMC Genomics, 2014
    Co-Authors: Konstantinos Papadimitriou, Pierre Renault, Rania Anastasiou, Eleni Mavrogonatou, Jochen Blom, Nikos C Papandreou, Stavros J Hamodrakas, Stephanie Ferreira, Philip Supply
    Abstract:

    Background Within the genus Streptococcus, only Streptococcus thermophilus is used as a starter culture in food fermentations. Streptococcus macedonicus though, which belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC), is also frequently isolated from fermented foods mainly of dairy origin. Members of the SBSEC have been implicated in human endocarditis and colon cancer. Here we compare the genome sequence of the dairy isolate S. macedonicus ACA-DC 198 to the other SBSEC genomes in order to assess in silico its potential adaptation to milk and its pathogenicity status.

  • comparative genomics of the dairy isolate Streptococcus macedonicus aca dc 198 against related members of the Streptococcus bovis Streptococcus equinus complex
    BMC Genomics, 2014
    Co-Authors: Konstantinos Papadimitriou, Pierre Renault, Rania Anastasiou, Eleni Mavrogonatou, Jochen Blom, Nikos C Papandreou, Stavros J Hamodrakas, Stephanie Ferreira, Philip Supply
    Abstract:

    Within the genus Streptococcus, only Streptococcus thermophilus is used as a starter culture in food fermentations. Streptococcus macedonicus though, which belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC), is also frequently isolated from fermented foods mainly of dairy origin. Members of the SBSEC have been implicated in human endocarditis and colon cancer. Here we compare the genome sequence of the dairy isolate S. macedonicus ACA-DC 198 to the other SBSEC genomes in order to assess in silico its potential adaptation to milk and its pathogenicity status. Despite the fact that the SBSEC species were found tightly related based on whole genome phylogeny of streptococci, two distinct patterns of evolution were identified among them. Streptococcus macedonicus, Streptococcus infantarius CJ18 and Streptococcus pasteurianus ATCC 43144 seem to have undergone reductive evolution resulting in significantly diminished genome sizes and increased percentages of potential pseudogenes when compared to Streptococcus gallolyticus subsp. gallolyticus. In addition, the three species seem to have lost genes for catabolizing complex plant carbohydrates and for detoxifying toxic substances previously linked to the ability of S. gallolyticus to survive in the rumen. Analysis of the S. macedonicus genome revealed features that could support adaptation to milk, including an extra gene cluster for lactose and galactose metabolism, a proteolytic system for casein hydrolysis, auxotrophy for several vitamins, an increased ability to resist bacteriophages and horizontal gene transfer events with the dairy Lactococcus lactis and S. thermophilus as potential donors. In addition, S. macedonicus lacks several pathogenicity-related genes found in S. gallolyticus. For example, S. macedonicus has retained only one (i.e. the pil3) of the three pilus gene clusters which may mediate the binding of S. gallolyticus to the extracellular matrix. Unexpectedly, similar findings were obtained not only for the dairy S. infantarius CJ18, but also for the blood isolate S. pasteurianus ATCC 43144. Our whole genome analyses suggest traits of adaptation of S. macedonicus to the nutrient-rich dairy environment. During this process the bacterium gained genes presumably important for this new ecological niche. Finally, S. macedonicus carries a reduced number of putative SBSEC virulence factors, which suggests a diminished pathogenic potential.

  • Comparative genomics of the dairy isolate Streptococcus macedonicus ACA-DC 198 against related members of the Streptococcus bovis/Streptococcus equinus complex.
    BMC Genomics, 2014
    Co-Authors: Konstantinos Papadimitriou, Pierre Renault, Rania Anastasiou, Eleni Mavrogonatou, Jochen Blom, Stavros J Hamodrakas, Stephanie Ferreira, Philip Supply, Nikos Papandreou, Bruno Pot
    Abstract:

    BACKGROUND: Within the genus Streptococcus, only Streptococcus thermophilus is used as a starter culture in food fermentations. Streptococcus macedonicus though, which belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC), is also frequently isolated from fermented foods mainly of dairy origin. Members of the SBSEC have been implicated in human endocarditis and colon cancer. Here we compare the genome sequence of the dairy isolate S. macedonicus ACA-DC 198 to the other SBSEC genomes in order to assess in silico its potential adaptation to milk and its pathogenicity status. RESULTS: Despite the fact that the SBSEC species were found tightly related based on whole genome phylogeny of streptococci, two distinct patterns of evolution were identified among them. Streptococcus macedonicus, Streptococcus infantarius CJ18 and Streptococcus pasteurianus ATCC 43144 seem to have undergone reductive evolution resulting in significantly diminished genome sizes and increased percentages of potential pseudogenes when compared to Streptococcus gallolyticus subsp. gallolyticus. In addition, the three species seem to have lost genes for catabolizing complex plant carbohydrates and for detoxifying toxic substances previously linked to the ability of S. gallolyticus to survive in the rumen. Analysis of the S. macedonicus genome revealed features that could support adaptation to milk, including an extra gene cluster for lactose and galactose metabolism, a proteolytic system for casein hydrolysis, auxotrophy for several vitamins, an increased ability to resist bacteriophages and horizontal gene transfer events with the dairy Lactococcus lactis and S. thermophilus as potential donors. In addition, S. macedonicus lacks several pathogenicity-related genes found in S. gallolyticus. For example, S. macedonicus has retained only one (i.e. the pil3) of the three pilus gene clusters which may mediate the binding of S. gallolyticus to the extracellular matrix. Unexpectedly, similar findings were obtained not only for the dairy S. infantarius CJ18, but also for the blood isolate S. pasteurianus ATCC 43144. CONCLUSIONS: Our whole genome analyses suggest traits of adaptation of S. macedonicus to the nutrient-rich dairy environment. During this process the bacterium gained genes presumably important for this new ecological niche. Finally, S. macedonicus carries a reduced number of putative SBSEC virulence factors, which suggests a diminished pathogenic potential.

  • milk adaptation and pathogenic potential among members of the Streptococcus bovis Streptococcus equinus complex
    2014
    Co-Authors: Konstantinos Papadimitriou, Pierre Renault, Rania Anastasiou, Eleni Mavrogonatou, Jochen Blom, Nikos C Papandreou, Stavros J Hamodrakas, Stephanie Ferreira, Philip Supply, Bruno Pot
    Abstract:

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