Detection of replication-competent circular single stranded DNA from Deoni cattle

Bovine meat and milk factors (BMMF) having structural similarity to plasmids of Acinetobacter baumanni and some single stranded (ss) DNA viruses are free circulating replication-competent circular ssDNA molecules which were first isolated from serum of Bos taurus animals. Isolation of BMMF from tissues of multiple sclerosis as well as some cancers led researchers to conclude that the consumption of these agents through milk and meat have a positive correlation with these diseases and that the absence of such molecules in B. indicus animals could account to the low occurrence of cancer in those areas consuming products of indigenous animals. Hence, the present study was designed to investigate its presence in Deoni, one of the indigenous cattle breeds of India. The DNA isolated from milk samples were subjected to rolling circle amplification (RCA) using exo-resistant random primers. The products of RCA were then used as template for PCR for amplification of circular DNA. The amplicons obtained of size around 2000bp were cloned in E. coli and sequenced. The BLASTn, multiple sequence alignment and phylogenetic analysis of the obtained sequences were carried out to identify the similarities of these isolates. The sequence showed maximum homology with either BMMF2 or plasmids of Acinetobactor spp. Replication initiation protein (Rep) which showed similarity to bacterial plasmids was present in the sequence. This is the pioneer report on the presence of BMMF in milk of indigenous cattle of India. Keywords: BMMF, replication-competent, circular ssDNA, Deoni