Unveiling genotypic diversity of Theileria orientalis in lethal outbreaks among bovines in Karnataka, India.

Theileria orientalis, the causal agent of oriental theileriosis, is known to cause mild disease in cattle and buffalo across the world. Recently, different genotypes of T. orientalis have emerged as pathogenic, causing high reported morbidity in cattle. This study focuses on investigating three suspected outbreaks of oriental theileriosis that resulted in fatalities among crossbred and indigenous bulls in Karnataka, India. Examination of blood smears revealed the presence of T. orientalis piroplasms within erythrocytes. The genetic characterization of T. orientalis was conducted by targeting specific markers, including the mpsp gene, p23 gene, and ribosomal DNA markers (18S rRNA gene, ITS-1, and ITS-2). Analysis based on the 18S rRNA gene unveiled the presence of both Type A and Type E genotypes of T. orientalis in the outbreaks. The mpsp gene-based analysis identified genotype 7 of T. orientalis in crossbred cows, whereas genotype 1 (Chitose B) was found to be present in indigenous bulls. Haplotype network analysis based on the mpsp gene revealed the presence of 39 distinct haplotypes within the 12 defined genotypes of T. orientalis with a high haplotype diversity of 0.9545 ± 0.017. Hematological and biochemical analysis revealed a decrease in calcium, hemoglobin levels, red blood cell counts, and phosphorus. This study constitutes the initial documentation of a clinical outbreak of oriental theileriosis in indigenous bulls with genotype 1 (Chitose 1B). Substantial epidemiological investigations are imperative to gain a comprehensive understanding of the geographical distribution of distinct genotypes and the diverse clinical manifestations of the disease across various hosts.

Molecular survey and phylogenetic analysis of tick-borne pathogens in ticks infesting cattle from two South Indian states.

In this study, the molecular survey of cattle ticks and tick-borne pathogens in various agroclimatic zones in Karnataka and Kerala states, India, and phylogenetic analysis of gene sequences were accomplished. Overall, 240 pooled tick DNA samples from two states were used for the identification of three tick genera and nine tick-borne pathogens by using the PCR method and sequencing. The distribution of Haemaphysalis (Ha.), Hyalomma (Hy.), and Rhipicephalus (R.) species were 5.0, 17.5, and 65.8% in Karnataka and 5.8, 11.7, and 65.0% in Kerala, respectively. The prevalence of Anaplasma marginale, Babesia bovis, Rickettsia species, and Trypanosoma evansi was 8.3, 0.8, 6.7, and 0.0% in Karnataka and 14.2, 0.0, 8.3, and 8.3% in Kerala, respectively. The pooled tick DNA samples were negative for Bartonella species, Borrelia species, Coxiella burnetti, Pasteurella multocida, and Theileria species. The season-wise analysis revealed a high occurrence of Ha. species in all seasons except for post-monsoon, Hy. and Rhipicephalus species in monsoon season in Karnataka, and all three tick genera were present in monsoon season in Kerala. The sequence analysis of mitochondrial cytochrome oxidase subunit 1 gene facilitated the identification of tick species namely, Ha. bispinosa, Ha. japonica, Hy. excavatum, R. annulatus, R. decoloratus, R. microplus, and R. sanguineus. The Rhipicephalus species was a major tick in these two states, and Rickettsia endosymbiont and Trypanosoma evansi in tick were detected in this study. This study represents the first report about the presence of Rickettsia massiliae in Ha. bispinosa in Karnataka and Trypanosoma evansi in R. species in Kerala. Phylogenetic analysis revealed sequence homology between the different isolates from India and neighbouring countries. Thus, the study provides key information on the distribution of ticks and tick-borne pathogens of cattle in Karnataka and Kerala, which will aid in developing and strategizing effective control measures.

Global and countrywide prevalence of subclinical and clinical mastitis in dairy cattle and buffaloes by systematic review and meta-analysis.

In the present study, subclinical mastitis (SCM) and clinical mastitis (CM) prevalence for various countries in the World were calculated by using online and offline databases. The SCM and CM prevalence studies reported during 1967-2019 were collected, reviewed, and a meta-analysis was done in R-Software. A total of 222 and 150 studies from the World and 103 and 37 studies from India on SCM and CM, respectively were included. The pooled prevalence of SCM and CM were 42% [Confidence Interval (CI) 38-45%, Prediction Interval (PI) 10-83%] and 15% [CI 12-19%, PI 1-81%] in the World respectively, 45% [CI 40-49%, PI 11-84%] and 18% [CI 14-23%, PI 3-60%] in India respectively. Continent-wise analysis indicated a higher prevalence of SCM in North America and CM in Europe and among the countries, a higher SCM prevalence in Uganda and CM in the United Kingdom was observed. Further, species-wise indicated a higher SCM and CM prevalence in buffaloes of the World than the cattle. Based on method-wise, SCM and CM prevalence were high in somatic cell count and clinical examination, respectively in the World. The SCM prevalence was higher than CM and indicated the importance of SCM in dairy cattle. This might result in low milk productivity in dairying and may set off losses to dairy farmers. Hence, there is an urgent need to reduce the SCM and CM prevalence by implementing scientific dairy management, good feeding practices, and timely therapeutic interventions for increasing the benefits from dairying to the farmers in the World.