16S rRNA gene sequencing of non-lactic acid bacteria cultures from lait caillé in Burkina Faso

The objective of this investigation was to provide information on the identity of non-lactic acid bacteria originating from traditional lait caillé and capable of growing abundantly on the standard media used for dairy LAB isolation. Specifically, Gram positive catalase positive and Gram negative bacteria growing on MRS and M17 agar were considered for molecular identification
MRS and M17 agar plates previously inoculated with traditional lait caillé were used to screen for Gram positive catalase positive and Gram negative bacteria. Successive streaking were performed to purify colonies. Culture purity, cells morphology were analysed by microscopy. Gram and catalase tests were done to select Gram negative and Gram positive catalase positive bacteria. (GTG)5-based rep-PCR fingerprint followed by cluster analysis, sequencing of 16S rRNA gene and database search in GenBank were performed to identify the isolates.
Data showed a predominance of Klebsiella pneumoniae/K. quasipneumoniae/K. variicola among Gram negative bacteria and a variety of species among Gram positive catalase positive bacteria such as Kocuria spp., Bacillus cereus group species, Macrococcus caseoliticus, Clostridium bifermentans, Staphylococcus hominis.
These data are useful as they gave some information on the presence of bacteria associated with emerging public health risks such as Klebsiella pneumonia species complex, Bacillus cereus group species, Kocuria spp. occurring in a traditional spontaneously fermented milk product. They also gave further insights for a broader investigation on non-lactic acid bacteria occurring in traditional fermentation of unpasteurised milks and for evaluation and development of selective media for Lactic acid bacteria growth.