Molecular studies on the prevalence of Tick borne Haemoprotozoan and Rickettsial infections in Canine and vector ticks

Abstract

The present study was conducted from August, 2020 to October, 2022 to determine the prevalence of haemoprotozoan and rickettsial infections in clinically suspected canines and vector ticks of Jammu region.The overall prevalence of tick borne haemoprotozoan and rickettsial infections in canine population of Jammu region was recorded as 24.3% (n= 92/378). The overall prevalence of Babesia canis vogeli was 10.58% (40/378) followed by Ehrlichia canis (7.67%, 29/378), mixed infections (3.70%, 14/378), Babesia gibsoni (2.11%, 8/378) and Hepatozoon canis (0.26%, 1/378). Out of total prevalence, Babesia canis vogeli was recorded with higher prevalence in dogs followed by Ehrlichia canis, Babesia gibsoni and Hepatozoon canis. Categorically, among the age groups of dogs, the prevalence of haemoprotozoan and rickettsial infection was significantly (pand#706;0.05) high in 6-12 months (52.77%) of age group as compared to 1year and above (14.22%) age group of canine. Monsoon recorded significantly (pand#706;0.05) highest infection rate (27.40%) as compared to winter (6.90%). As per breed, German shepherd were shown non-significantly (pgt0.05) higher prevalence of 39.7%. Males showed non-significantly higher infection (25.5%) as compared to females (20%). Haematological alterations in infected group of canines revealed significant drop in mean values of haemoglobin count, platelet count, packed cell volume count and Total erythrocyte count as compared to healthy control group of canines.A blood sample was considered as positivefor Ehrlichia canis when amplified with the size of 380bp product. Similarly, product size of 602bp, 671bp and 666 bp were yielded by Babesia canis vogeli, Babesia gibsoni and Hepatozoon canis, when amplified by targeting 18S rRNA genefor all three of the parasites. A total of four PCR products comprising Babesia canis vogeli and Ehrlichia canis, representing different isolates of Jammu region were sent for sequencing. The sequence information received was analysed using Basiclocal alignment search tool (BLAST, NCBI) and DNA Star, Laser gene software. The submitted sequences of Babesia canis vogeli and Ehrlichia canis belonging to Jammu region are under process with NCBI. newline Identification using standard keys and tick mounting procedures revealed that all the ticks collected from 257 tick infested dogs were identified as Rhipicephalus sanguineus. The prevalence of tick infestation was recorded significantly (plt0.05) higher among 6-12 months (82.29%) of age group in monsoon season (86.98%). German shepherd breeds (86.79%) were at higher risk of gaining infection while males (77.34%) were recorded with significantly higher tick infestation as compared to females (48.36%). Standardisation and optimization of PCR on ticks revealed the presence of DNA of Babesia canis vogeliand Ehrlichia canis, in vector ticks, collected from suspected canines of Jammu region.At the last phase of the study period, duplex PCR was also standardized for simultaneous detection of Babesia canis vogeli and Ehrlichia canis was performed using the similar primers which we used in molecular studies for blood and vector tick samples, respectively at the annealing temperature of 52ºC. newline newline