Short communication: Intra- and inter-individual milk microbiota variability in healthy and infected water buffalo udder quarters.

The concept that ruminant mammary gland quarters are anatomically and physiologically unrelated has been recently challenged by immunological evidence. How this interdependence reflects on individual quarter milk microbiota is unknown. The aim of the present study was to cover this gap by investigating the interdependence of quarters among the same mammary gland at the milk microbiota level using next-generation sequencing of the V4-16S rRNA gene. A total of 52 samples were included in this study and classified as healthy or affected by subclinical mastitis. Extraction of DNA, amplification of the V4-16S rRNA gene, and sequencing using Ion Torrent Personal Genome Machine (Thermo Fisher Scientific, Waltham, MA) were carried out. We found that the intra-individual variability was lower than the inter-individual one. The present findings further support at milk microbiota level the hypothesis of the interdependence of quarters, as previously demonstrated following immunological studies, suggesting that individual factors (e.g., immunity, genetics) may have a role in modulating milk microbiota.

Development of 23 individual TaqMan® real-time PCR assays for identifying common foodborne pathogens using a single set of amplification conditions.

Most of the acute intestinal diseases are caused by foodborne pathogens with infants and elderly people being at major risk. The aim of this study was to develop a procedure to simultaneously detect 20 foodborne pathogens in complex alimentary matrices such as milk, cheese and meat. The list of targets include, among the others, Listeria spp., Salmonella spp., Shigella spp., Escherichia coli spp., Campylobacter spp., Clostridium spp. and Staphylococcus aureus. The accuracy of detection was determined by using ATCC strains as positive and negative controls. The achieved sensitivity of each of assays was 1 pg of genomic DNA, which was equivalent to ∼1 cfu. The working ranges of the TaqMan(®) Real-time PCR assays, when used quantitatively on cheese and meat samples inoculated with serial dilution of Listeria spp., Listeria monocytogenes, S. aureus, Salmonella enterica, Shigella boydii, E. coli O157:H7, Bacillus cereus, Campylobacter coli, Yersinia enterocolitica, Enterobacter sakazakii and Pseudomonas aeruginosa was 10(8) cfu/g to 10(4) cfu/g. No matrix interferences were observed.