UspA Gene Based Characterization of Escherichia coli Strains Isolated from Different Disease Conditions in Goats

Escherichia coli (E. coli) carry six universal stress protein (usp) genes: A, C, D, E, F and G, and the expression of these genes are triggered by various environmental stresses. The uspA gene is important for survival of E. coli during cellular growth, adhesion and motility. The present study was conducted to characterize three pathogenic E. coli strains isolated from the cases of diarrhoea, pneumonia and mastitis in goats. A polymerase chain reaction (PCR) was performed to amplify 884 bp open reading frame (ORF) of the uspA gene from the E. coli strains. The uspA amplicons of the three E. coli strains were sequenced, and compared with the published sequences in NCBI GenBank, and their phylogenetic relationships were analysed. The diarrheic strain showed significant variation in the nucleotide composition as compared to pneumonia and mastitis associated strains. In the ORF of uspA gene, silent mutations were noticed in the nucleotide sequence positions 27, 33, 207 and 316, which were not reflected phenotypically. Among the peptides, ‘KHILIAVDLS’ could be a putative candidate for use as epitope in diagnostics. Further, comprehensive studies on sequence analysis of the uspA gene will help us to understand the distribution, variability, and phylogenetic relationships of different pathogenic E. coli isolated from different disease conditions in goats.