Molecular detection and phylogenetic analysis of Toxocara vitulorum in feces and milk samples from naturally infected water buffaloes

Abstract

Toxocara vitulorum infects cattle and water buffalo, leading to mild to severe infection in calves and has wide geographic distributions, especially in tropical and subtropical countries. This work aimed to assess the prevalence, distributions, and phylogeny of T. vitulorum in water buffaloes in different parts of Sivas, one of the essential buffalo-breeding areas in Türkiye. T. vitulorum was found in 42 (8.23%) and 54 (10.58%) fecal (n:510) samples using microscopic and molecular techniques, respectively. T. vitulorum was higher in animals aged 0-6 months compared to other groups. Furthermore, when animals aged 0-6 months were grouped within themselves, the prevalence of T. vitulorum in 1-3 month-old-animals was higher than in both younger than one month and older than three months. T. vitulorum was detected in fecal samples obtained from animals older than six months. In colostrum/milk samples (n:100), T. vitulorum-larvae were found in 4% and 10% with microscopic and molecular techniques, respectively. The larvae were detected in colostrum/milk samples in the mother between the 2nd and 28th days postpartum-period. The ITS-1-gene of 11 PCR-positive samples was sequenced. The 98.99–100% nucleotide identity was determined between our T. vitulorum isolates and those present in GenBank. In conclusion, this is the first molecular survey and phylogenetic analysis of T. vitulorum in fecal and colostrum/milk samples from naturally infected water buffaloes. Data obtained in this study will help to understand the life cycle and epidemiology of the nematode. Data also revealed that veterinarians should consider older animals as well as young animals in their control program of nematode infections in farms.