Prevalence and comparison of Streptococcus infantarius subsp. infantarius and Streptococcus gallolyticus subsp. macedonicus in raw and fermented dairy products from East and West Africa

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