Structural and sequence analysis of the RPO30 gene of sheeppox and goatpox viruses from India

Sheeppox and goatpox are transboundary viral diseases of sheep and goats that cause significant economic losses to small and marginal farmers worldwide, including India. Members of the genus Capripoxvirus (CaPV), namely Sheeppox virus (SPPV), Goatpox virus (GTPV), and Lumpy skin disease virus (LSDV), are antigenically similar, and species differentiation can only be accomplished using molecular approaches. The present study aimed to understand the molecular epidemiology and host specificity of SPPV and GTPV circulating in India through sequencing and structural analysis of the RNA polymerase subunit-30 kDa (RPO30) gene. A total of 29 field isolates from sheep (n = 19) and goats (n = 10) belonging to different geographical regions of India during the period: Year 2015 to 2023, were analyzed based on the sequence and structure of the full-length RPO30 gene/protein. Phylogenetically, all the CaPV isolates were separated into three major clusters: SPPV, GTPV, and LSDV. Multiple sequence alignment revealed a highly conserved RPO30 gene, with a stretch of 21 nucleotide deletion in all SPPV isolates. Additionally, the RPO30 gene of the Indian SPPV and GTPV isolates possessed several species-specific conserved signature residues/motifs that could act as genotyping markers. Secondary structure analysis of the RPO30 protein showed four α-helices, two loops, and three turns, similar to that of the E4L protein of vaccinia virus (VACV). All the isolates in the present study exhibited host preferences across different states of India. Therefore, in order to protect vulnerable small ruminants from poxviral infections, it is recommended to take into consideration a homologous vaccination strategy.

An updated review on bluetongue virus: epidemiology, pathobiology, and advances in diagnosis and control with special reference to India

Bluetongue (BT) is an economically important, non-contagious viral disease of domestic and wild ruminants. BT is caused by BT virus (BTV) and it belongs to the genus Orbivirus and family Reoviridae. BTV is transmitted by Culicoides midges and causes clinical disease in sheep, white-tailed deer, pronghorn antelope, bighorn sheep, and subclinical manifestation in cattle, goats and camelids. BT is a World Organization for Animal Health (OIE) listed multispecies disease and causes great socio-economic losses. To date, 28 serotypes of BTV have been reported worldwide and 23 serotypes have been reported from India. Transplacental transmission (TPT) and fetal abnormalities in ruminants had been reported with cell culture adopted live-attenuated vaccine strains of BTV. However, emergence of BTV-8 in Europe during 2006, confirmed TPT of wild-type/field strains of BTV. Diagnosis of BT is more important for control of disease and to ensure BTV-free trade of animals and their products. Reverse transcription polymerase chain reaction, agar gel immunodiffusion assay and competitive enzyme-linked immunosorbent assay are found to be sensitive and OIE recommended tests for diagnosis of BTV for international trade. Control measures include mass vaccination (most effective method), serological and entomological surveillance, forming restriction zones and sentinel programs. Major hindrances with control of BT in India are the presence of multiple BTV serotypes, high density of ruminant and vector populations. A pentavalent inactivated, adjuvanted vaccine is administered currently in India to control BT. Recombinant vaccines with DIVA strategies are urgently needed to combat this disease. This review is the first to summarise the seroprevalence of BTV in India for 40 years, economic impact and pathobiology.

Basic reproduction number (R0), an epidemiological tool for prioritizing livestock diseases' An example of Karnataka

Livestock diseases become burden to the dairy farmers and state animal husbandry departments, and causes huge economic loss. Basic reproduction number [R0], indicates the number of secondary cases in susceptible population from one diseased animal. In the present study, R0 was calculated by using 5 statistical methods for 13 livestock diseases, which was used to prioritize livestock diseases and calculated herd immunity threshold, vaccination coverage required. Time series data on livestock disease outbreaks, month, year, clinically diagnosed cases, death cases were collected from Department of Animal Husbandary and Veterinary Services. Govt. of Karnataka during the period 2000–18. The mean R0 values were >1 for bacterial (4), viral (5) and parasitic (4) diseases. The livestock diseases were prioritized for high transmission potential as haemorrhagic septicaemia [HS] (2.51) followed by Peste des petits ruminants [PPR] (2.22), black quarter [BQ] (1.89), foot-and-mouth disease [FMD] (1.71), theileriosis [TE] (1.70), enterotoxaemia [ET] (1.54), anthrax [AX] (1.48), sheep and goat pox [SGP] (1.44), rabies [RA] (1.39), babesiosis [BA] (1.38), bluetongue [BT] (1.31) and fasciolosis [FA] (1.27) based on mean R0 values for Karnataka. The herd immunity threshold was high for HS [60.2%] followed by PPR [55.0%], BQ [47.1%], FMD [41.5%] and other diseases. The vaccination coverage required showed highest levels for HS, followed by PPR, BQ, FMD, TE, ET, etc. Thus, R0 values may be used for prioritizing livestock diseases by policy makers and for planning the necessary preventive measures. The herd immunity threshold and vaccination coverage obtained for livestock diseases will help in allocating the scarce resources for vaccination effectively and to prevent livestock diseases outbreaks in Karnataka.

Emerging and Transboundary Animal Viral Diseases: Perspectives and Preparedness

The epidemics and pandemics of a few infectious diseases during the past couple of decades have accentuated the significance of emerging infectious diseases (EIDs) due to their influence on public health. Although Asia region has been identified as the epicentre of many EIDs and upcoming infections, several new pathogens have also emerged in the past in other parts of the world. Furthermore, the emergence of new viral diseases/infections, such as Rift Valley fever, West Nile fever, SARS coronavirus, Hendra virus, avian influenza A (H5N1), Nipah virus, Zika virus and swine influenza A (H1N1) virus, from time to time is a glaring example threatening adversely both animal and public health globally. Infectious diseases are dynamic and concerning due to their epidemiology and aetiological agents, which is manifested within a host, pathogen and environment continuum involving domestic animals, wildlife and human populations. The complex relationship among host populations and other environmental factors creates conditions for the emergence of diseases. The factors driving the emergence of different emerging infectious disease (EID) interfaces include global travel, urbanisation and biomedical manipulations for human EIDs; agricultural intensification for domestic animal EIDs; translocation for wildlife EIDs; human encroachment, ex situ contact and ecological manipulation for wildlife–human EIDs; encroachment, new introductions and ‘spill-over’ and ‘spill-back’; and technology and industry for domestic animal–human EIDs. The concepts of sanitary and phytosanitary (SPS) measures and biosecurity have gained recognition globally in almost all the realms of human activities, including livestock health and production management. This chapter provides the experience gained in the control and management of a few important TADs and EIDs along with the successes, constraints, limitations and future research needs for developing better control approaches.

Haematological and biochemical alterations in native sheep experimentally infected with bluetongue virus serotype-2

The study was designed to determine the haematological and biochemical alterations in sero-negative native sheep following the experimental bluetongue virus serotype-2 (BTV-2) infection. The BTV infected group comprised 14 sheep inoculated with 6 ml of clarified virus containing 1×106/ml TCID50 of BTV-2 by intradermal route. The uninfected control group comprised 6 animals inoculated with 6 ml of cell culture medium without virus by intradermal route. The blood and serum samples were analyzed at 0, 1, 2, 3, 7, 11, 14, 21 and 45 days post-infection (dpi). Significant changes were observed in all the haematological and biochemical parameters studied. Marked leucopenia was observed from 2 to 7 dpi in BTV infected group. Significant leucocytosis was documented during 11 to 14 dpi in infected group. Significant thrombocytopenia was observed during 2 to 14 dpi whereas significantly low packed cell volume (PCV) and haemoglobin (Hb) values were observed between 3 and 21 dpi in BTV infected group. Differential leucocyte count revealed significantly low lymphocyte percentage on day 3 and high on day 11 in infected group. The various biochemical enzymes like alanine aminotransferase (ALT) showed significantlyhigh values during 3 to 21 dpi, aspartate aminotransferase (AST) during 3 to 21 dpi, alkaline phosphatise (ALP) during 3 to 11 dpi and creatine kinase (CK) during 7 to 14 dpi in BTV infected group. The result of our study demonstrated significantly decreased levels of total leucocyte count, total platelet count, haemoglobin and PCV values while significantly increased levels of ALT, AST, ALP and CK values in BTV infected group. On histopathological examination, spleen and lymph nodes showed depletion of lymphoid cells, liver and kidney showed degeneration, congestion and haemorrhage at many places. The BTV nucleic acid was detected from blood and tissues by RT-PCR. These findings indicated the damage to various soft tissue organs and muscles as a sequel to vascular endothelial damages caused by BTV.

Bioinformatics Applications in Advancing Animal Virus Research

Viruses serve as infectious agents for all living entities. There have been various research groups that focus on understanding the viruses in terms of their host-viral relationships, pathogenesis and immune evasion. However, with the current advances in the field of science, now the research field has widened up at the ‘omics’ level. Apparently, generation of viral sequence data has been increasing. There are numerous bioinformatics tools available that not only aid in analysing such sequence data but also aid in deducing useful information that can be exploited in developing preventive and therapeutic measures. This chapter elaborates on bioinformatics tools that are specifically designed for animal viruses as well as other generic tools that can be exploited to study animal viruses. The chapter further provides information on the tools that can be used to study viral epidemiology, phylogenetic analysis, structural modelling of proteins, epitope recognition and open reading frame (ORF) recognition and tools that enable to analyse host-viral interactions, gene prediction in the viral genome, etc. Various databases that organize information on animal and human viruses have also been described. The chapter will converse on overview of the current advances, online and downloadable tools and databases in the field of bioinformatics that will enable the researchers to study animal viruses at gene level.

Epidemiological Perspective in Managing Viral Diseases in Animals

Since the first report of a viral disease associated with plants, the fascinating field of virology has evolved and aided mankind altogether. Viral infections are known for inflicting colossal economic losses worldwide in food/work/companion animals. During the last few decades, emergence of a number of new viral diseases in animals, humans and plants has been visualized. Animal disease surveillance and monitoring is essential for the sustainability of healthy livestock production systems internationally. Preparedness for combating the emerging, re-emerging, exotic and transboundary diseases requires comprehensive monitoring and precision detection systems that are pliable under the field situations. With collective and concerted scientific interventions, a few of the animal viral diseases have been stamped out globally or regionally. Rinderpest, popularly called cattle plague, was eradicated from India in 2006 and globally in 2011. Notably, India achieved the disease-free status by OIE in 2014 for African horse sickness (peste equine), a deadly viral disease of equines. Likewise, equine infectious anaemia (EIA) and equine influenza (EI) have been controlled to a greater extent in India by adopting surveillance and monitoring along with zoo sanitary measures. Overall, there is a need for developing the ‘One World, One Health’ concept using multidisciplinary, regional and international networking to control major economically important emerging/re-emerging infectious diseases of humans and animals. This chapter describes various strategies for combating viral diseases of livestock.

Isolation and genome analysis of a lytic Pasteurella multocida Bacteriophage PMP-GAD-IND

Currently used alum precipitated and oil adjuvant vaccines against HS caused by Pasteurella multocida B:2, have side effects and short-lived immunity, leading to regular catastrophic outbreaks in bovines in Asian subcontinent. The need for the development of an improved vaccine with longer immunity and the ability to differentiate between vaccinated and infected is essential. Pasteurella phage isolated in present study belongs to family Siphoviridae. PMP-GAD-IND phage exhibited lytic activity against vaccine strain (P52) as well as several field strains of P. multocida (B:2), and fowl cholera agent (P. multocida A:1).The phage has a double stranded DNA (dsDNA) with a genome of 46 335 bp. The complete genome sequence of the Pasteurella multocida phage has been deposited in Gen Bank with accession no: KY203335. PMP-GAD-IND being a lytic phage with broad activity range has a potential to be used in therapy against multidrug resistant P. multocida infections.

SIGNIFICANCE AND IMPACT OF THE STUDY

The present work is a part of research for the development of an improved phage lysate marker vaccine and a companion DIVA assay against haemorhagic septicaemia. This study describes the isolation and genome analysis of PMP-GAD-IND a lytic Pasteurella multocida bacteriophage.

Comparative Neuropathology of Major Indian Bluetongue Virus Serotypes in a Neonatal BALB/c Mouse Model

Bluetongue virus (BTV) is neurotropic in nature, especially in ruminant fetuses and in-utero infection results in abortion and congenital brain malformations. The aim of the present study was to compare the neuropathogenicity of major Indian BTV serotypes 1, 2, 10, 16 and 23 by gross and histopathological lesions and virus distribution in experimentally infected neonatal BALB/c mice. Each BTV serotype (20 μl of inoculum containing 1 × 10⁵ tissue culture infectious dose [TCID]₅₀/ml of virus) was inoculated intracerebrally into 3-day-old mice, while a control group was inoculated with mock-infected cell culture medium. Infection with BTV serotypes 1, 2 and 23 led to 65-70% mortality at 7-9 days post infection (dpi) and caused severe necrotizing encephalitis with neurodegenerative changes in neurons, swelling and proliferation of vascular endothelial cells in the cerebral cortex, cerebellum, midbrain and brainstem. In contrast, infection with BTV serotypes 10 and 16 led to 25-30% mortality at 9-11 dpi and caused mild neuropathological lesions. BTV antigen was detected by immunohistochemistry, direct fluorescence antibody technique and confocal microscopy in the cytoplasm of neuronal cells of the hippocampus, grey matter of the cerebral cortex and vascular endothelial cells in the midbrain and brainstem of BTV-1, -2, -10, -16 and -23 infected groups from 3 to 20 dpi. BTV nucleic acid was detected in the infected brain tissues from as early as 24 h up to 20 dpi by VP7 gene segment-based one-step reverse transcriptase polymerase chain reaction. This study of the relative neurovirulence of BTV serotypes is likely to help design suitable vaccination and control strategies for the disease.

Genome wide host gene expression analysis in mice experimentally infected with Pasteurella multocida

Pasteurella multocida causes acute septicemic and respiratory diseases, including haemorrhagic septicaemia, in cattle and buffalo with case fatality of 100%. In the present study, mice were infected with P. multocida (1.6 × 10³ cfu, intraperitoneal) to evaluate host gene expression profile at early and late stages of infection using high throughput microarray transcriptome analyses. Several differentially expressed genes (DEGs) at both the time points were identified in P.multocida infected spleen, liver and lungs. Functional annotation of these DEGs showed enrichment of key pathways such as TLR, NF-κB, MAPK, TNF, JAK-STAT and NOD like receptor signaling pathways. Several DEGs overlapped across different KEGG pathways indicating a crosstalk between them. The predicted protein—protein interaction among these DEGs suggested, that the recognition of P. multocida LPS or outer membrane components by TLR4 and CD14, results in intracellular signaling via MyD88, IRAKs and/or TRAF6 leading to activation of NFκB and MAPK pathways and associated cytokines.