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 and genetic diversity in isolates of Trypanosoma evansi from naturally infected horse and dogs by using RoTat 1.2 VSG gene in Madhya Pradesh, India.

BACKGROUND: Trypanosoma evansi is a protozoan parasite that can infect a wide range of animals and is widespread around the world. In this study, we analyzed four fatal cases of T. evansi infection using clinical, parasitological, and molecular approaches. We also explored the genetic diversity, demographic history, and population-genetic structure of T. evansi using available Rode Trypanozoon antigenic type (RoTat) 1.2 gene sequences. METHODS AND RESULTS: Clinical findings of infected animals revealed high fever, anemia, weakness, and anorexia. The animals were treated with diminazene aceturate, which was moderately effective, and hematobiochemical parameters showed changes in hemoglobin and glucose levels. The molecular and genetic diversity of T. evansi was analyzed using the RoTat 1.2 VSG gene. Phylogenetic and haplotype analysis revealed two distinct clusters of T. evansi circulating in India. The genetic diversity indices, neutrality tests, gene flow, and genetic differentiation outcomes confirmed the genetic diversity of the T. evansi population, with a lack of uniformity. The identification of two distinct clusters, exhibiting differential demographic histories and evolutionary forces, implies that the clusters may have undergone independent evolutionary trajectories or experienced different environmental pressures. CONCLUSION: The present findings underlined the need of an early and precise diagnosis in order to treat and control T. evansi infections, and the RoTat 1.2 VSG gene is an important genetic marker for understanding the genetic diversity and evolutionary history of T. evansi. This knowledge can be used to create tailored strategies to control and manage the infection in an endemic region.

Development of an enzyme linked immunosorbent assay using recombinant cathepsin B5 antigen for sero-surveillance of bovine tropical fasciolosis.

Bovine tropical fasciolosis, caused by Fasciola gigantica, is a major parasitic disease in tropical countries responsible for significant production losses in animal husbandry practices. The disease is transmitted by the Radix sp. snails. In the early developmental stage of the parasite, the juveniles and immature flukes cause considerable damage to the liver parenchyma of the bovine host while migrating through the liver. The cathepsin (cat) B5 is a cysteine protease that is present in the excretory-secretory product of the fluke both in immature and adult stages. The early detection of fasciolosis is very critical in effective disease management. In this study, the cathepsin B5 gene from newly excysted juveniles were cloned, sequenced and analyzed. The phylogenetic analysis revealed existence of two distinct clades. The clade I includes cat B 1 to B3 whereas clade II consist of cat B4 to B7. Further, the present study was aimed to develop an enzyme linked immuno sorbent assay (ELISA) using recombinant cat B5 antigen. The developed enzyme immuno assay showed 95.3 % sensitivity and 92.4 % specificity with a cut-off of 60 % percent positive. It revealed weighted Kappa value as 0.768 (95 % CI 0.648-0.889) when compared with ELISA using native cathepsin protein. Hence, the developed assay can be exploited as a potent tool in the diagnosis and sero-surveillance of bovine tropical fasciolosis.

Exploration of machine learning models to predict the environmental and remote sensing risk factors of haemonchosis in sheep flocks of Rajasthan, India.

Globally haemonchosis in sheep is a known devastating disease imposing considerable economic loss. Understanding the environmental risk factors and their role is essentially required to manage the disease successfully. In this study, 14 years' disease data was analysed to predict the risk factors responsible for the occurrence of the disease. Season-wise analysis revealed high incidence during monsoon and post-monsoon and least in winter and summer seasons. The linear discriminant analysis (LDA) revealed the significant environmental and remote sensing risk factors contributing to haemonchosis incidence as enhanced vegetation index, leaf area index, potential evapotranspiration and specific humidity. Further, significant ecological and environmental risk factors identified using LDA were subjected to the climate-disease modelling and risk maps were generated. Basic reproduction number (R0) was estimated and was ranged from 0.76 to 2.08 for >1000 egg per gram of faeces (EPG) in four districts whereas R0 values of 1.09-1.69 for >2000 EPG in three districts indicating the severity of the infection. The random forest and adaptive boosting models emerged out as best fitted models for both the EPG groups. The results of the study will help to focus on high-risk areas of haemonchosis in sheep to implement the available control strategies and better animal production globally.

Silent Trypanosoma evansi infection in humans from India revealed by serological and molecular surveys, and characterized by variable surface glycoprotein gene sequences.

BACKGROUND: The importance of emerging atypical human trypanosomosis is gaining momentum due to increasing detection and its possible impact on human health. A cross sectional study of atypical human trypanosomosis due to Trypanosoma evansi was carried out in Kolkata and Canning area of West Bengal state of India where previously a death was reported. METHODS: In this study blood and serum samples from 173 individuals were collected during August to December 2014. To check the presence of antibodies against T. evansi, card agglutination test and for the presence of T. evansi specific DNA, PCR were conducted. RESULTS: T. evansi infection was identified in 5.2% (9/173) human blood samples by CATT serological test (Card agglutination test for trypanosomosis). PCR targeting VSG gene sequences suggested active T. evansi infection in 2.89% (5/173). VSG gene sequences herein determined for five isolates from human cases shared high similarity (89.4-100%). Phylogenetic inference clustered the human isolates with other isolates from different host species from India and other countries, forming a clade exclusive of Indian isolates (84.0 to 100% sequence similarity). CONCLUSION: First report of symptomless human T. evansi infection detected by combined serological and PCR assays. First phylogenetic analysis of VSG gene sequences including human isolates of T. evansi in which Indian isolates of T. evansi from human and other hosts clustered in a single clade.

Existence of genetic lineages within Asian genotype of Taenia solium-Genetic characterization based on mitochondrial and ribosomal DNA markers.

Taenia solium cysticercosis is a potentially eradicable neglected zoonotic disease with public health importance. The genetic lineages of T. solium in Asia and Africa/America are distinct and the genetic composition of the parasite was found to influence the clinical symptoms in patients with cysticercosis. In the present study, the Cysticerci collected from pigs of two southern states of India (Karnataka and Andhra Pradesh) were genetically characterized based on mitochondrial (COX 1 and Cyt b) and ribosomal (ITS-1 and TBR) DNA markers. The study confirms the existence of two mitochondrial lineages of the parasite as Asian and African/American. Cytochrome oxidase 1 (COX 1) based analysis revealed the existence of two sub-lineages of the parasite within the Asian lineage based on the polymorphism at 994 position as 994A/G. In India, both the sub-lineages were identified and genetic divergence among different Indian isolates was evident. Further, the sequence analysis of Cytochrome B (Cyt b) revealed the existence of six sub-lineages of T. solium in India as 69T/69G, 97A/97G as well as 264T/264C. The analysis of nucleotide sequence of large subunit ribosomal DNA (TBR) revealed the existence of two sub-lineages in India based on the deletion of a nucleotide at 624th position. The cysts collected in the present study were more closely related to those of China and Indonesia than with other Indian isolates. Further, the sequence analysis did not indicate the presence of Taenia asiatica in the examined pigs and African/American lineages of T. solium. The results of the present study help to better understand the genetic diversity of T. solium in India.

A systematic review and meta-analysis on the prevalence of infectious diseases of Duck: A world perspective.

The Indian poultry industry is one of the fast-growing sectors of which duck farming plays an important role. Duck population in India is 33.51 million that is concentrated towards north-east and southern parts of the country who rears mainly for eggs and meat. Duck diseases are of great concern as they badly affect the financial status of the small, landless farmers. Databases such as Google Scholar, PubMed, J gate were used to search articles between 2000 and 2019 that showed the prevalence of viral, bacterial, and parasitic duck diseases. R open source software was used to derive forest plots by statistical analysis. Pooled prevalence estimates of duck diseases worldwide was found to be 20% (95%-CI:15-26). Also, continent-wise analysis of all duck diseases has revealed highest prevalence in North America, followed by Asia, Africa, Europe,Oceania and South America. This prevalence of data would be helpful to the policymakers to develop appropriate intervention strategies to prevent and control diseases in their respective locations.

Bovine babesiosis: An insight into the global perspective on the disease distribution by systematic review and meta-analysis.

Bovine babesiosis is continuing as a great threat to the livestock sector causing havoc production losses with significant morbidity and mortality. Being a tick-borne disease, the great complexity in the agent-host- vector relationship has severely hampered the sincere efforts towards the development of an effective vaccine against bovine babesiosis. In these circumstances, assessing the global scenario of disease prevalence is a prerequisite to strategize the available control measures. Keeping this in view, the objective of this study was to estimate the pooled prevalence of bovine babesiosis globally. The literature search was conducted to identify all relevant published articles reporting the prevalence of bovine babesiosis and a total of 163 studies were found eligible for final systematic review and meta-analysis. Meta-analysis was conducted using meta package of R software and summary estimates of the prevalence were calculated. Meta analysis of 81099 samples from 62 countires representing six continents revealed pooled global prevalence of bovine babesiosis as 29% (95% CI = 24%-34%) with estimated prevalence of active infection as 16% (95% CI = 13%-20%) and seroprevalence as 50% (95% CI = 45%-56%) using random effects model. Continent wise highest prevalence of bovine babesiosis in South America 64% (95% CI = 49%-77%) and lowest in Asia 19% (95% CI = 14%-25%). Highest prevalence was estimated with B. bigemina 22% (95% CI = 18%-27%) and least prevalence was recorded with B. divergens 12% (95% CI = 2%-46%). The pooled prevalence estimates generated in the study is revealing an increase in disease trend and the need for immediate planning of mitigation strategies paralleled with the development of early diagnostic methods to reduce the impact of disease throughout the world.

Epidemiological and genetic characterization of larval stages of Fasciola gigantica in snail intermediate hosts in Karnataka State, India.

Fasciolosis in ruminants in India is caused by the liver fluke Fasciola gigantica. Radix (Lymnaea) spp. are known to carry the infective stages of this parasite. Understanding the seasonal prevalence of F. gigantica infection in the intermediate host is of extreme importance in order to elucidate the transmission dynamics of the parasite. So the present study was designed to determine the bioclimatic distribution of larval stages of F. gigantica in Radix spp. snails as well as to explore the genetic diversity of F. gigantica in three geographical regions (Deccan plateau, Western Ghats and coastal region) of Karnataka. The lymnaeid snails were sampled (n = 2077) for a period of one year (June 2015 to May 2016) at 24 sites. The snails were morphologically identified and the infection status was established through cercarial shedding and nested polymerase chain reaction (PCR) based technique targeting second internal transcribed spacers (ITS-2) of nuclear ribosomal DNA. The sensitivity of PCR (8.2%) for detection of F. gigantica infection within snail is significantly higher than cercarial shedding (4.3%) with an overall prevalence of 5.1%. The prevalence of infection was higher in winter than in the rainy and summer seasons (6.2% instead of 4.6% and 4.3% respectively). Deccan plateau (5.8%) showed a higher prevalence of infection compared to Western Ghats (5.2%) and Coastal region (3.6%). The sequencing ITS-2 region permitted the identification of the parasite as F. gigantica which is having high implication in studying the population genetic structure of the parasite in the country. In conclusion, overall results indicated that Radix spp. snails harboured F. gigantica developmental stages throughout the year and nested PCR was found to be sensitive and specific for detection of F. gigantica infection in snails compared to routine parasitological techniques.

Comparative evaluation of recombinant LigB protein and heat-killed antigen-based latex agglutination test with microscopic agglutination test for diagnosis of bovine leptospirosis.

This study aimed to develop latex agglutination test (LAT) using recombinant leptospiral immunoglobulin-like protein (LigB) (rLigB) antigen and compare its diagnostic efficacy with LAT using conventional heat-killed leptospiral antigen and microscopic agglutination test (MAT) in diagnosing bovine leptospirosis. The PCR-amplified 1053-bp ligB gene sequences from Leptospira borgpetersenii Hardjo serovar were cloned in pET 32 (a) vector at EcoRI and NotI sites and expressed in BL21 E. coli cells as fusion protein with thioredoxin (-57 kDa) and characterized by SDS-PAGE and immunoblot. Out of 390 serum samples [cattle (n = 214), buffaloes (n = 176)] subjected to MAT, 115 samples showed reciprocal titre≥100 up to 1600 against one or more serovars. For recombinant LigB protein/antigen-based LAT, agglutination was observed in the positive sample, while no agglutination was observed in the negative sample. Similarly, heat-killed leptospiral antigen was prepared from and used in LAT for comparison with MAT. A two-sided contingency table was used for analysis of LAT using both the antigens separately against MAT for 390 serum samples. The sensitivity, specificity and positive and negative predictive values of recombinant LigB LAT were found to be 75.65, 91.27, 78.38 and 89.96 %, respectively, and that of heat-killed antigen-based LAT were 72.17, 89.82, 74.77 and 88.53 %, respectively, in comparison with MAT. This developed test will be an alternative/complementary to the existing battery of diagnostic assays/tests for specific detection of pathogenic Leptospira infection in bovine population.