Search

Small ruminants (sheep and goats) are susceptible to foot-and-mouth disease (FMD), while studies with due emphasis on their role in the disease epidemiology have been meagre. The present study summarizes the results of clinico-molecular investigation of FMD in sheep and goats across several states of India during 2008–2014, where a total of 51 clinical epithelial tissue samples (vesicle/tongue/gum/foot epithelium) from sheep and 78 from goats were found positive for FMD virus (FMDV) serotype O in serotyping ELISA and multiplex reverse transcription-PCR. The VP1 region-based phylogenetic analysis demonstrated the involvement of O/ME-SA/Ind2001 lineage of serotype O virus in the outbreaks. The field viruses recovered from both small and large ruminant population during the same time period showed a close genetic relationship suggesting frequent inter-species transmission of virus. Since the disease often remains clinically camouflaged in small ruminants, the animals silently infected with FMD may pose potential threats to the in-contact livestock. Regular vaccination combined with surveillance and monitoring of protective antibody status in these species is therefore crucial to the effective control of FMD in the country. [ABSTRACT FROM AUTHOR]

Foot-and-mouth disease (FMD) virus serotype O is the most common cause of FMD outbreaks in India and three of the six lineages that have been described are most frequently detected, namely Ind2001, PanAsia and PanAsia 2. We report the full capsid sequence of 21 serotype O viruses isolated from India between 2002 and 2012. All these viruses belong to the Middle East–South Asia (ME–SA) topotype. The serological cross-reactivity of a bovine post-vaccination serum pool raised against the current Indian vaccine strain, O/IND/R2/75,was tested by virus neutralisation test with the 23 Indian field isolates, revealing a good match between the vaccine and the field isolates. The cross reactivity of the O/IND/R2/75 vaccine with 19 field isolates from other countries (mainly from Asia and Africa) revealed a good match to 79% of the viruses indicating that the vaccine strain is broadly cross-reactive and could be used to control FMD in other countries. Comparison of the capsid sequences of the serologically non-matching isolates with the vaccine strain sequence identified substitutions in neutralising antigenic sites 1 and 2, which could explain the observed serological differences. [ABSTRACT FROM AUTHOR]

Polymorphism of bovine leukocyte antigen (BoLA) DRB3 gene is being intensively investigated for potential association with economically important diseases of cattle. Accordingly, we investigated the association of DRB3 Exon 2 polymorphism as evidenced by the variation in the binding pockets with variability in immune response to inactivated trivalent (O, A and Asia1) foot and mouth disease virus (FMDV) vaccine in a closed population of crossbred cattle. Antibody titer of ⩾1.8 was set as the cut off value to distinguish the protected (P1.8) and unprotected (⩾1.8) animals. Eleven different alleles of over 3% frequency were detected in the population. We found that DRB3 alleles 8 0201, 8 0801 and 8 1501 always ranked high for protective immune response whereas alleles 8 0701, 8 1103 and 8 1101 consistently ranked low for unprotected immune response for all the three serotypes. Rank correlation of DRB3 alleles among the three serotypes was positive, high in magnitude and statistically significant (P < 0.05). Logistic regression analysis revealed that odds of protection from the vaccine were highest for all the three serotypes if allele 8 1501 was present and strengthened the results of allele ranking. Predicted amino acid substitution in the peptide binding pockets revealed that all the important sites had high Wu-Kabat index. Similarly, specific residues in pockets were crucial for immune response to FMD vaccine. There were specific substitutions in un-protected alleles such as absence of acidic amino acids substituted by basic amino acid at β71, presence of non-polar cysteine or basic histidine at b30 and presence of polar tyrosine at β37. From the observations, we hypothesize that the substitutions lead to unique conformational changes in the protein products of the studied alleles that would associate with the protective or unprotective antibody response to FMDV vaccine. The knowledge has potential implications in future selection programs if integrated with the complete BoLA haplotype details and production traits of the herd. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the endometrial expression of pro-inflammatory cytokines (IL1β, IL6, IL8 and TNFα) along with TLR4 and CD14 in normal and endometritic buffaloes. The genitalia were collected in the abattoir and divided into three groups as normal (gr. I = 12), clinical endometritis (CE, gr. II = 12) based on positive color reaction to white side test of uterine discharge and sub-clinical endometritis (SCE, gr. III = 12) based on endometrial cytology (presence of ⩾5% PMNs) and histopathology. The equal numbers of genitalia were grouped into follicular and luteal stage in each group. Endometrial tissue scrapings were used for total RNA extraction and cDNA was transcribed and amplified by Real time PCR. The results showed several fold higher expression of all cytokine transcripts in CE (gr. II), whereas significant up-regulation of CD14 (1 to 2-fold), IL6 (15 to 36-fold), IL8 (8 to 14-fold) and TNFa (10 to 11-fold) mRNA was observed in SCE. This indicates that the evaluation of expression patterns of certain cytokines gene holds promise to diagnose the severity and degree of uterine inflammation. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to develop a competitive inhibition ELISA (CI-ELISA) for detection of antibodies to bovine viral diarrhea virus (BVDV) using the helicase domain of NS3 (non-structural) protein and monoclonal antibody (MAb) against it and to estimate its sensitivity and specificity using two commercial ELISA kits as independent references. The 45-kDa helicase domain of NS3 protein of BVDV was expressed in Escherichia coli and 18MAbs were developed against it. MAb-11G8 was selected for use in CI-ELISA on the basis of maximum inhibition (90%) obtained with BVDV type 1 infected calf serum. Based on the distribution of percent inhibition of known negative sera (n =166), a cut-off value was set at 40% inhibition. In testing 914 field serum samples of cattle (810) and buffaloes (104), the CI-ELISA showed a relative specificity of 95.75% and 97.38% and sensitivity of 96% and 94.43% with Ingenesa kit and Institut Pourquier kit, respectively. This study proved that the use of helicase domain of NS3 (45-kDa) is equally good as the whole NS3 protein (80-kDa) used in commercial kits for detection of BVDV antibodies in cattle and buffaloes. [Copyright &y& Elsevier]

Abstract: India is one of the countries with the highest prevalence of human rabies throughout the world. Dogs are primarily responsible for rabies transmission. Among them, stray dogs play a major role in that country. Parenteral vaccination programmes are insufficient to eliminate rabies partly due to difficulties in establishing satisfactory immunisation coverage in the dog population in view of the high proportion of stray dogs. Oral vaccination may be a useful adjunct to parenteral vaccination by increasing dog vaccination coverage. Safety, immunogenicity and efficacy of Rabidog® SAG2 bait were evaluated in Indian stray dogs in captivity. Safety of SAG2 was demonstrated by the absence of adverse clinical sign, salivary excretion and absence of replication of the vaccine strain in brain and salivary glands of 21 vaccinated dogs, even when immunodepressed. Efficacy was shown 109 days post-vaccination after challenge with a highly virulent street rabies virus which killed all five controls whereas all nine vaccinated dogs survived, despite the fact that only five out of nine had seroconverted before challenge. [Copyright &y& Elsevier]

Abstract: In India, systematic genotype replacement has been observed for serotype A foot-and-mouth disease virus. After a decade of co-circulation of genotypes VI and VII, genotype VII emerged as the single dominant genotype since 2001. To derive possible explanations for such epochal evolution dynamics, in vitro intergenotype growth competition experiments involving both co- and superinfection regimes were conducted. Coinfection of BHK-21 cells demonstrated abrupt loss in the genotype VI viral load with commensurate increase in the load of genotype VII as measured by the genotype differentiating ELISA, RT-PCR and real-time RT-PCR. The superinfection dynamics was shaped by temporal spacing of infection, where the invading genotype VII took more number of passages than coinfection to eventually overtake the resident genotype VI. It was speculated that such superior replicative fitness of genotype VII could have been a possible factor for the ultimate dominance of genotype VII in nature. [Copyright &y& Elsevier]