Revisiting the genotypes of Theileria equi based on the V4 hypervariable region of the 18S rRNA gene.

Introduction: Equine theileriosis, an economically important disease that affects horses and other equids worldwide, is caused by a tick-borne intracellular apicomplexan protozoa Theileria equi. Genotyping of T. equi based on the 18S rRNA gene revealed the presence of two, three, four or five genotypes. In previous published reports, these genotypes have been labelled either alphabetically or numerically, and there is no uniformity in naming of these genotypes. The present study was aimed to revisit the phylogeny, genetic diversity and geographical distribution of T. equi based on the nucleotide sequences of the V4 hypervariable region of the 18S rRNA gene available in the nucleotide databases. Methods: Out of 14792 nucleotide sequences of T. equi available in the GenBank™, only 736 sequences of T. equi containing the complete V4 hypervariable region of the 18S rRNA gene (>207 bp) were used in multiple sequence alignment. Subsequently, a maximum likelihood phylogenetic tree was constructed based on the Kimura 2-parameter model (K2+I). Results: The phylogenetic tree placed all the sequences into four distinct clades with high bootstrap values which were designated as T. equi clades/ genotypes A, B, C and D. Our results indicated that the genotype B of Nagore et al. and genotype E of Qablan et al. together formed the clade B with a high bootstrap value (95%). Furthermore, all the genotypes probably originated from clade B, which was the most dominant genotype (52.85%) followed by clades A (27.58%), and C (9.78%) and D (9.78%). Genotype C manifested a comparatively higher genetic diversity (91.0-100% identity) followed by genotypes A (93.2-99.5%), and B and D (95.7-100%). The alignment report of the consensus nucleotide sequences of the V4 hypervariable region of the 18S rRNA gene of four T. equi genotypes (A-D) revealed significant variations in one region, between nucleotide positions 113-183, and 41 molecular signatures were recognized. As far as geographical distribution is concerned, genotypes A and C exhibited far-extending geographical distribution involving 31 and 13 countries of the Asian, African, European, North American and South American continents, respectively. On the contrary, the genotypes B and D exemplified limited distribution with confinement to 21 and 12 countries of Asian, African and European continents, respectively. Interestingly, genotypes A and C have been reported from only two continents, viz., North and South America. It was observed that genotypes A and C, and B and D exhibit similar geographical distribution. Discussion: The present study indicated the presence of only four previously described T. equi genotypes (A, B, C and D) after performing the molecular analyses of all available sequences of the complete V4 hypervariable region of the 18S rRNA gene of T. equi isolates in the GenBank™.

Population genetic characterization of Theileria annulata based on the cytochrome b gene, with genetic insights into buparvaquone susceptibility in Haryana (India).

The present investigation was aimed at population genetic characterization of Theileria annulata on the basis of the cytochrome b (cyt b) gene along with the evaluation of status of buparvaquone resistance in Haryana (India). The sequences originating from China, Egypt, India, Iran, Iraq, Tunisia, Turkey and Sudan were included in the analysis. The maximum likelihood tree based on the Tamura-Nei (TN93+G) model placed all the sequences of T. annulata into a single clade. The median-joining haplotype network exemplified geographical clustering between T. annulata haplotypes originating from each country. Only five haplotypes (7.81 %) were shared between any two countries, while the remaining 59 haplotypes (92.19 %) were singleton and unique to one country. The values of pairwise genetic distance (FST) between all the populations indicated huge genetic differentiation (> 0.25) between different T. annulata populations, barring the FST value between Iraq and Turkey (0.14454) which suggested a moderate differentiation. Contrary to the FST index, the values of gene flow (Nm) between T. annulata populations were very low. The neutrality indices and mismatch distributions indicated a population expansion in the Indian T. annulata population. Furthermore, the secondary structure and homology modeling of the partial cyt b protein is also reported. The molecular analysis of newly generated sequences for buparvaquone resistance revealed that all the isolates were susceptible to buparvaquone treatment. However, two novel mutations at positions V203I and V219I in between the Q01 and Q02 drug-binding regions of the cyt b gene were observed for the first time.

An insight into misidentification of the small-subunit ribosomal RNA (18S rRNA) gene sequences of Theileria spp. as Theileria annulata.

BACKGROUND: There had been isolated reports of the presence of novel Theileria annulata genotypes based on the 18S rRNA gene sequence data from India, Pakistan and Saudi Arabia; but, these studies were restricted to limited field samples. Additionally, no comparative study has been conducted on all the isolates of this parasite from different countries whose sequences are available in the nucleotide databases. Therefore, we aimed to study the genetic diversity of T. annulata based on all available nearly complete 18S rRNA gene sequences in the GenBank™. Out of a total of 312 gene sequences of T. annulata available in the NCBI database, only 70 nearly complete sequences (> 1527 bp) were used for multiple sequence alignment. RESULTS: The maximum likelihood tree obtained using TN93 + G + I model manifested two major clades. All the valid host-cell transforming Theileria species clustered in one clade. The T. annulata designated sequences occupying this clade clustered together, excluding two isolates (DQ287944 and EU083799), and represented the true T. annulata sequences (n = 54). DQ287944 and EU083799 exhibited close association with Theileria lestoquardi. In addition, 14 Indian sequences formed a large monophyletic group with published Theileria orientalis sequences. The broad range of sequence identity (95.8-100%) of T. annulata designated sequences indicated the presence of different Theileria spp. A closer analysis revealed the presence of three Theileria spp., namely, T. annulata, T. orientalis, and two isolates (DQ287944 and EU083799) closely related to T. lestoquardi. The true T. annulata sequences manifested 98.8-100% nucleotide identity within them. EU083799 and 14 misidentified Indian T. annulata sequences exhibited the highest similarity with T. lestoquardi (98.6-98.8%) and T. orientalis (98.0-99.9%) in comparison with the other Theileria spp. of domestic and wild ruminants. CONCLUSION: In the course of analyzing the genetic diversity of T. annulata, we identified the nearly complete 18S rRNA gene sequences of other Theileria spp. that have not only been misidentified as T. annulata in the GenBank™, but are also published as T. annulata. Moreover, a high level of sequence conservation was noticed in the 18S rRNA gene of true T. annulata and T. orientalis sequences.

First Record of Molecular Confirmation, Phylogeny and Haplotype Diversity of Haemonchus contortus from Gaddi (breed) Goats of North India

Abstract: In the present study, molecular identification and genotypic characterization of H. contortus was carried out targeting 28S-18S rRNA intergenic spacer. Faecal samples of Gaddi goats were collected and subjected to qualitative screening. The samples exhibiting the presence of strongyle type eggs were introduced to faecal culturing. The larvae retrieved were molecularly confirmed as of H. contortus species and the phylogenetics was performed. For the estimation of evolutionary divergence in between the present study isolates with the GenBank archived sequences, maximum composite likelihood model was employed. Nucleotide and haplotype diversity indices and Fu's Fs were also estimated. Approximately 260 bp size amplicons retrieved were confirmatory for the presence of H. contortus species. Phylogenetic analysis also accentuated that present parasite isolates were of H. contortus only. The nucleotide diversity (π) obtained was 0.06696, whereas, haplotype diversity was 0.92549 [95% CI: 0.77778-1.0000]. In between the isolates, Fu's Fs statistic value was positive (1.566), evidencing a deficiency of alleles, which would have happened due to recent population bottleneck. The recovered representative sequences were deposited in GenBank under the accession numbers LC600315-LC600317.To the best of our knowledge, the present study is the first report of phylogeny and haplotype diversity of H. contortus isolated from Gaddi goats of North India. The present study would also serve the basis for future detailed molecular epidemiological studies using discriminative markers for the assessment of genetic diversity in different populations of H. contortus in different hosts of the study area.

Phylogenetic analysis, genetic diversity and geographical distribution of Babesia caballi based on 18S rRNA gene.

The present investigation was aimed to study the presence of Babesia caballi clades upon phylogenetic analysis of all available V4 hypervariable 18S rRNA gene sequences in GenBank in addition to the intra- and interclade genetic diversity in B. caballi and the distribution of parasite clades in different countries. Out of altogether 155 small-subunit ribosomal RNA gene sequences of B. caballi available in the database, only 92 sequences with a complete V4 hypervariable region (>293 bp) were used in multiple sequence alignment. The phylogenetic tree placed all the sequences into two distinct clades with high bootstrap values which are designated as B. caballi clades A and B. Clade A was further divided into two subclades A1 and A2 with 98% bootstrap support. On the contrary, clade B contained multiple small subclades which either lacked bootstrap support or did not have enough bootstrap support to further group them into subclades. All the sequences of B. caballi were 91.5-100% identical with each other. Clade B manifested a comparatively higher genetic diversity (95.2-100% identity) amongst sequences as opposed to clade A (97.3-100% identity). Moreover, it indicated 91.5-93.5%, 92.9-94.6% and 91.5-94.6% nucleotide identity with B. caballi subclades A1, A2, and clade A, respectively. Significant nucleotide variations were observed in one region, between nucleotide positions 126-178, in some of the sequences. A total of 21 molecular signature residues were identified in the V4 hypervariable region. The alignment report of the V4 hypervariable region of 18S rRNA gene of clades A and B exhibited nucleotide variation at nine and 24 places, respectively. The distribution map of all the clades of B. caballi is also reported. The number of 18S rRNA gene sequences employed in the study is relatively high compared to previous studies. Therefore, a fair comparison of definite genetic variations between isolates/sequences from different countries was carried out.

Molecular confirmation and anthelmintic efficacy assessment against natural trichurid infections in zoo-housed non-human primates.

INTRODUCTION: This study aimed to assess Trichuris species infection and evaluate the anthelmintic efficacy of fenbendazole and ivermectin against natural trichurid infections in non-human primates (NHPs), kept at Mahendra Chaudhury (MC) Zoological Park, Chhatbir, India. MATERIALS AND METHODS: Molecular confirmation of Trichuris infection was carried out using polymerase chain reaction targeting internal transcribed spacer sequences, and anthelmintic efficacy was assessed by fecal egg count reduction test, respectively. RESULTS: A 710 base pair product confirmed Trichuris species infection in NHPs. Fenbendazole, 10 mg/kg body weight orally for 5 consecutive days and ivermectin, 100 µg/kg body weight orally for 3 alternate days proved effective and showed a maximum fecal egg reduction of 99.20% and 100% (P < .05) at day 7 post-treatment. CONCLUSIONS: This study highlighted the molecular confirmation of Trichuris species in non-human primates and its management using fenbendazole and ivermectin.

Gastrointestinal parasitic infections in Indian Gaddi (goat) breed bucks: clinical, hemato-biochemical, parasitological and chemotherapeutic studies.

The present study was envisaged with an aim to evaluate gastrointestinal parasitic infections in a herd of conserved Gaddi (goat) breed bucks (6-9 months of age) kept on semi-intensive feeding management. The individuals (n = 20) representing the herd were selected and divided into two groups; group I (n = 10), clinically ill and group II (n = 10), sub clinically infected individuals. The clinical examination revealed anemia, emaciation and rise in body temperature of the individuals of group I as compared to group II. The detailed copro-parasitological examination and copro-culture revealed the presence of eggs of Moniezia expansa and larvae of Haemonchus species, respectively in the fecal samples of both clinically and sub clinically infected individuals. The hemato-biochemical parameters proved vital indicators of the health of group I individuals and exhibited decline in the values of hemoglobin, packed cell volume and total erythrocyte count as compared to group II. Significant (P < 0.05) hypoproteinemia, hypoalbuminemia, hypoglycemia and increased levels of alanine aminotransferase and aspartate aminotransferase were observed in infected individuals as compared to treated ones. The detailed parasitological, hemato-biochemical observations and clinical findings elucidated and supported the presence of concurrent gastrointestinal parasitism in the herd. The significant improvement was observed in the health status of the herd after 1 month of the therapeutic management, which was carried out using a combination of fenbendazole and praziquantel in both clinically and sub clinically infected individuals.

Prevalence of gastrointestinal parasites in dogs of Palampur, Himachal Pradesh.

A total of 246 faecal/scat samples of the dogs were screened by direct and floatation concentration technique to study the gastrointestinal (GI) tract parasitism in dogs of Palampur, Himachal Pradesh, India. Detailed coprological examination targeting different seasons, age groups and living styles of the dogs revealed an overall 28.04 % of GI parasitism with highest prevalence in summer season (37.87 %). Stray dogs harbored 47.29 % GI parasites in comparison to 19.19 % of pet dogs. Highest prevalence of GI parasitism was observed in the pups, below 3 months of age (39.13 %), followed by the dogs with the age ranging from 3 months to 1 year (26.38 %) and lowest in dogs of the age ranging from 1 to 3 years (6.77 %). Amongst all the parasites, Toxocara canis (44.93 %) infection was highest, followed by Dipylidium caninum (17.39 %) and hookworms (15.94 %).

Histopathological and morphological studies on natural Cysticercus fasciolaris infection in liver of Wistar rats.

Descriptive morphology of multifocal hepatic cysts found in eight of forty five (17.78 %) Wistar rats sacrificed during pharmacological studies related to herbal formulations was studied. The creamish to white cysts were of varying sizes, ranging from 3-8 mm in diameter. Morphological studies of these cysts depicted the presence of metacestodes of Taenia taeniaeformis i.e. Cysticercus fasciolaris inside them. The scolex of metacestode revealed four suckers and rostellum armed with two distinct rows of characteristic pen knife shaped hooks (characteristics of taeniid cestodes). The average size of large hooks was 392.92 ± 10.12 µ and that of small hooks was 240.64 ± 14.26 µ. The average size of suckers was 304.36 ± 12.33 µ. Histopathology of hepatic tissue surrounding the cysts revealed zones of fatty change, inflammation, granulation tissue and metaplasia. However, the histopathology of stomach and small intestines didn't show any significant lesions.

Equine trypanosomosis in central and western Punjab: prevalence, haemato-biochemical response and associated risk factors.

The detection of Trypanosoma evansi in blood is intricate, primarily in chronic stage of infection, as the parasitaemia is often low and fluctuating. The climatic conditions of the target area of Punjab (a province of India with a total of 34,000 horses and ponies used for sports and transport) are conducive for the parasite propagation. The objective of present investigation was to assess the prevalence of T. evansi in central and western Punjab by PCR and card agglutination test (CATT/T. evansi) in relation to clinico-haematobiochemical alterations and risk factors associated with latent trypanosomosis. A total of 169 equine blood and serum samples tested by CATT/T. evansi revealed 16 cases positive, with 6.8% from central plain and 13.63% from western zone. To assess the specificity of serological test, PCR1 was performed using established primer pair TR3 5'-GCG CGG ATT CTT TGC AGA CGA-3' and TR4 5'-TGC AGA CAC TGG AAT GTT ACT-3' for T. evansi. PCR2 applied with primer pair RoTat1.2F: 5'-ATG TCA ACG ATG CCT GTT ACA TTA CGC AC-3' and RoTat1.2R: 5'-TAA ATA TCA CTG TCA AGA CCT GCT GCG G-3' to rule out the consensus between the finding of the two PCR assays and agglutination test for T. evansi, which displayed results in concordance with PCR1. PCR assays showed 1.92 and 1.51% positive samples from central plain and western zone, respectively. With respect to PCR assay, CATT/T. evansi showed 100% sensitivity and 92.1% specificity. Microscopy showed a very low prevalence rate of 0.59% with only one sample positive with teaming parasitaemia. Comparison between sexes revealed higher positivity in mares by the three tests (BSE: 0.95%, PCR: 2.88%, CATT/T. evansi: 14.42%). The haemato-biochemical factors were found to be altered in PCR positive cases, while the mean value of vital parameters lied in normal range in seropositive cases. The female horse (RR=0.0937, 95% CI=1.388-190.223%) population was found to be at the highest risk of seropositivity for T. evansi, particularly in the unorganized farms (RR=19.726, 95% CI=2.918-400.221%).