​Prevalence Risk Factor Analysis and Molecular Characterization of Canine Monocytic Ehrlichiosis in Maharashtra

Abstract

Background: The research work was undertaken with the aim to investigate the prevalence and influence of associated risk factors on canine monocytic ehrlichiosis (CME), by employing conventional and molecular techniques in naturally occurring ehrlichiosis in dogs from the geographical area of Pune and Satara, Maharashtra, India. Methods: Evaluation of 60 blood samples from dogs exhibiting illness clinically suggestive of CME was performed for the detection of Ehrlichia canis by conventional microscopy and PCR-based assays targeting 16S rRNA gene. The collected blood samples were also utilized immediately for estimation of haemato-biochemical parameters. Descriptive statistics along with chi-square test of association were performed by using SPSS software. Result: Microscopic examination of Geimsa stained thin blood smears revealed Ehrlichia canis morulae in 5.00% (03/60) samples. Processing of purified DNA from blood samples by Genus-specific 16SrRNA PCR, with known primers resulted in amplification of 477 bp product of 6.66% (04/60) samples evident of CME. Further two step nested PCR assay using published species-specific primers yielded 387 bp product in 16.66% (10/60) samples indicative of E. canis. Younger, exotic cross breed females dogs were found more prone compared to adults. Indian non-descript male counterparts and winter season being more favorable for CME. Sequence analysis of randomly selected representative samples from Pune and Satara each when aligned with nine isolates from India and western countries showed complete homology.