Risk factors for the carriage of Streptococcus infantarius subspecies infantarius isolated from African fermented dairy products

• Published in: PloS one 2019-11, Vol.14 (11), p.e0225452
• Main Authors: Gboko, Kossia D T, Traoré, Sylvain G, Sanhoun, Aimé R, Kirioua, Jérôme, Otaru, Nize, Kurt, Fabienne, Jaeger, Fabienne N, Isenring, Julia, Kaindi, Dasel W M, Kreikemeyer, Bernd, Renault, Pierre, Hattendorf, Jan, Meile, Leo, Jans, Christoph, Nguetta, Roland, Bonfoh, Bassirou
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Animals; Bacteria; Biology and Life Sciences; Biotechnology; Colorectal cancer; Confidence intervals; Consumer research; Consumers; Contamination; Cross-Sectional Studies; Cultured Milk Products - microbiology; Dairy products; Data collection; Demographics; Diet; Disease; Ecological monitoring; Ecology; Endocarditis; Epidemiology; Feces - microbiology; Female; Fermented milk products; Food; Food contamination; Food Microbiology - statistics & numerical data; Genes; Genetic research; Genomics; Gram-Positive Bacterial Infections - diagnosis; Gram-Positive Bacterial Infections - epidemiology; Gram-Positive Bacterial Infections - microbiology; Health risks; Humans; Kenya - epidemiology; Laboratories; Lactic acid; Lactic acid bacteria; Life Sciences; Livestock; Male; Medicine and Health Sciences; Microorganisms; Middle Aged; Milk; Milk - microbiology; Milk products; Multilocus Sequence Typing; Nutrition; Opportunist infection; Pathogenic microorganisms; Pathogens; People and Places; Population structure; Public health; Risk analysis; Risk Factors; RNA; RNA, Ribosomal, 16S - genetics; rRNA 16S; Streptococcus; Streptococcus - genetics; Streptococcus - isolation & purification; Streptococcus infections; Surveys; Tumors; Young Adult
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0225452

Streptococcus infantarius subsp. infantarius (Sii) has been identified as predominant lactic acid bacteria in spontaneously fermented dairy products (FDPs) in sub-Saharan Africa including Côte d'Ivoire. However, Sii belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC). Most SBSEC members are assumed to be involved as opportunistic pathogens in serious diseases in both humans and animals. A population-based cross-sectional survey, including 385 participants was conducted in Korhogo, northern Côte d'Ivoire, to identify risk factors for Sii fecal carriage, including consumption of local FDPs. A structured questionnaire was used to gather participant's socio-demographic and economic characteristics, their relation to livestock and dietary habits. In addition, fresh stool and milk samples were collected. The identification of Sii was done using a SBSEC-specific PCR assay targeting 16S rRNA and groEL genes. The overall prevalence of SBSEC and Sii carriage was 23.2% (confidence interval CI 95% = 18.9-27.5) and 12.0% (CI 95% = 8.4-15.5) for stool, respectively. Prevalence of Sii was significantly higher in consumers of artisanal butter compared with non-consumers (57.1% vs 10.1%, odds ratio OR: 11.9, 95% CI: 3.9-36.6), as well as in persons handling livestock (OR = 3.9; 95% CI = 1.6-9.3) and livestock primary products (OR = 5.7; 95% CI = 2.3-14.3). The closer contact with livestock was a risk factor for Sii fecal carriage. Sii strains were isolated from fresh and fermented milk products with a prevalence of 30.4% and 45.4%, respectively. Analysis of Sii population structure through the SBSEC multi locus sequence typing assay revealed a close relationship across human and dairy isolates, possibly linked to a Kenyan human isolate. All these outcomes underline the interest of in-depth investigations on the ecology, potential reservoirs and pathways of contamination by Sii at the human-animal-environment interface in comparison to yet to be collected data from Europe, Asia and the Americas to further elucidate the various roles of Sii.