Isolation and identification of lactic acid bacteria in mother,s breast milk using 16S ribosomal DNA sequencing method

Human breast milk is known to be the best food for rapidly growing infant scince breastfeeding protects the newborn against some diesease such as infection disease،asthma and allergy. This effect may be due to the useful and natural microflora of breast milk which could be depending on diets of mothers. For the first time، this study accomplished to evaluate microflora of mother’s breast milk along with sepration and identification of local bacteria that could be as a candidat for bacteriotherapy and possessing probiotic propertiesin Iran. In this study،309 different colonies were isolated from 20 breast milk samplesof mothers who were registered in Mshhad. The isolated were selected based on the results of catalase test، gram stain، and bacterial morphology. The results showed that 40 out of 309 selected bacteria were catalase negative and gram positive stain. The whole genomes of 16s ribosomal DNA of isolated colonies were amplified using polymerase chain reaction for identification down to the strain level. According to the results، the breast milk contains various species of enterococci، Streptococci، Staphylococci and Lactobacilli. The most abundant bacteria، enterococcus faeciumwasisolated from 50% of samples representing 47. 5% of the total isolated bacteria. Generally 10 and 27. 5 percentage of isolated bacteria were La. rhamnosusLc 705and Streptococcus salivarius، respectively، that were isolated from 20 and 35 percent of milk samples،respectively.