Zika virus – emergence,evolution, pathology,diagnosis, and control: current global scenario and future perspectives – a comprehensive review

This review converses the Zika virus which has attained global concern due to its rapid pandemic potential and impact on humans. Though Zika virus was first isolated in 1947, till the recent large-scale outbreak which occurred in Micronesia, in 2007, the virus was placed into the innocuous pathogen category. The World Health Organization on 1 February 2016 declared it as a ‘Public Health Emergency of International Concern.’ Of the note, American as well as Pacific Island strains/isolates is relatively closer to Asian lineage strains. The African and American strains share more than 87.5% and 95% homologies with Asian strains/isolates, respectively. Asian strains form independent clusters, except those isolated from China, suggesting relatively more diversity than African strains. Prevention and control are mainly aimed at the vector population (mosquitoes) with Aedes aegypti being the main species. Surveys in Africa and Asia indicated seropositivity in various animal species. However, so far its natural reservoir is unknown. There is an urgent need to understand why Zika virus has shifted from being a virus that caused mild illness to unforeseen birth defects as well as autoimmune-neurological problems. Unfortunately, an effective vaccine is not available yet. Availability of cryo-electron microscopy based on 3.8 Å resolution revealing mature Zika virus structure and the probable virus attachment site to host cell would provide critical insights into the development of antiviral treatments and vaccines.     

Social Dominance and Courtship and Mating Behaviour in Rams in Non-Competitive and Competitive Pen Tests

A group of 19 Merino rams was used to determine: (i) if body weight, age and testis characteristics are different between high (HR) and low-ranked (LR) rams, and (ii) how the competition between HR and LR rams for oestrous ewes affect their courtship and mating behaviour. Hierarchy was determined using the food competition test. The five first and five last ranked rams were individually exposed to oestrous ewes in pen tests, and the frequency of different courtship behavioural units, mounts and mates, and the time from test onset to each mate was recorded. The sexual behaviour of the five first ranked and the five last ranked rams was also tested in competition, pairing a HR and a LR ram. Age, body weight, body condition score, scrotal circumference, and testis firmness and resilience from HR and LR were not different. The display of courtship behavioural units was lower when rams were tested in competition but was not affected by the rank of the rams. The number of mates per test from HR rams was lower than that observed in LR rams when tested alone. While the number of mates decreased in LR rams in competition tests, it was not affected in HR rams. In summary, there was no relation between social rank and body weight, age or testis characteristics. LR rams were more effective than HR rams when mating oestrous ewes without competition. However, in competitive tests, although all rams modified their courtship strategies, LR rams were more affected by the presence of dominant rams than HR rams were by the presence of LR rams.     

Antigenic and genetic variations in European and North American equine influenza virus strains (H3N8) isolated from 2006 to 2007

Equine influenza virus (EIV) surveillance is important in the management of equine influenza. It provides data on circulating and newly emerging strains for vaccine strain selection. To this end, antigenic characterisation by haemaggluttination inhibition (HI) assay and phylogenetic analysis was carried out on 28 EIV strains isolated in North America and Europe during 2006 and 2007. In the UK, 20 viruses were isolated from 28 nasopharyngeal swabs that tested positive by enzyme-linked immunosorbent assay. All except two of the UK viruses were characterised as members of the Florida sublineage with similarity to A/eq/Newmarket/5/03 (clade 2). One isolate, A/eq/Cheshire/1/06, was characterised as an American lineage strain similar to viruses isolated up to 10 years earlier. A second isolate, A/eq/Lincolnshire/1/07 was characterised as a member of the Florida sublineage (clade 1) with similarity to A/eq/Wisconsin/03. Furthermore, A/eq/Lincolnshire/1/06 was a member of the Florida sublineage (clade 2) by haemagglutinin (HA) gene sequence, but appeared to be a member of the Eurasian lineage by the non-structural gene (NS) sequence suggesting that reassortment had occurred. A/eq/Switzerland/P112/07 was characterised as a member of the Eurasian lineage, the first time since 2005 that isolation of a virus from this lineage has been reported. Seven viruses from North America were classified as members of the Florida sublineage (clade 1), similar to A/eq/Wisconsin/03. In conclusion, a variety of antigenically distinct EIVs continue to circulate worldwide. Florida sublineage clade 1 viruses appear to predominate in North America, clade 2 viruses in Europe.     

Seroprevalences of antibodies against bovine leukemia virus, bovine viral diarrhea virus, Mycobacterium avium subspecies paratuberculosis, and Neospora caninum in beef and dairy cattle in Manitoba

Of 1204 dairy cows and 1425 beef cows sampled, 60.8% and 10.3% were seropositive for Bovine leukemia virus, 4.5% and 1.7% were seropositive for Mycobacterium avium subspecies paratuberculosis, and 8.3% and 9.1% were seropositive for Neospora caninum, respectively, while 28.1% of dairy herds had unvaccinated animals with titres > or = 1:64 for Bovine viral diarrhea virus.     

Cellular Immune Responses to 35 kDa Recombinant Antigen of Mycobacterium avium paratuberculosis

Mycobacterium avium paratuberculosis is the causative agent of Johne disease, a chronic ulcerative intestinal condition in ruminant animals. Owing to the predominance of cellular response in subclinical forms of the infection, identification of M. a. paratuberculosis antigens eliciting host cell-mediated immune (CMI) reaction is crucial for early control of the disease. A 35 kDa protein of M. a. paratuberculosis was studied for its ability to elicit CMI responses using a mouse model. Lymphoproliferation and IFN-γ response were used to measure the CMI response. Recombinant 35 kDa protein (P35) stimulated proliferation of mouse mononuclear splenocytes sensitized with M. a. paratuberculosis. The P35 elicited increased nitrite production from mononuclear splenocytes from M. a. paratuberculosis-sensitized mice. In addition, RT-PCR-based semiquantitative IFN-γ measurement showed that stimulation with P35 is associated with significant expression of IFN-γ mRNA in M. a. paratuberculosis-sensitized mouse splenocytes. The results indicate that the 35 kDa protein of M. a. paratuberculosis is associated with CMI response in the host.     

The studies on nutrient balances in crossbred cattle bulls fed chopped green sugarcane tops supplemented with some agro industrial by- products

Fifteen adult crossbred cattle bulls, 18-22 months old (mean body weight 286.33 + 9.43) were divided into 3 groups following RBD design and were fed sugarcane tops (SCT) supplemented with some agro-industrial byproducts and concentrate feeds to determine nitrogen, Ca and P in crossbred cattle bull. For this purpose, crossbred cattle bulls were fed for 30 days ad lib SCT supplemented with Wheat bran (WB), Lentil chuni (LC) and WB + LC (50:50) in Group I, II, and III respectively. The balance values were 15.28 + 2.70, 26.85 + 4.35 and 18.00 + 3.17 for nitrogen, 11.77 + 1.34, 12.94 + 2.96 and 15.38 + 1.15 for calcium, 11.74 + 0.64, 11.26 + 1.58 and 11.69 + 0.79 for phosphorus in group I, II and III, respectively. There were no significant differences among the experimental groups in Ca and P balance values but balance of nitrogen was significantly (P < 0.05) higher in group II as compared to group I and III. It may indicated that the rumen fermentation was more appropriate in group III where animals were fed 50% lentil chuni and 50% wheat bran (supplementation of both protein and energy).     

Effect of fertilizer application based on soil test crop response approach on active and passive pools of soil organic matter in maize–wheat cropping system

ABSTRACT

A long-term fertilizer experiment was initiated in kharif 2007 in a maize–wheat sequence at the Experimental Farm of Department of Soil Science, Chaudhary Sarwan Kumar Himachal Pradesh Krishi Vishvavidyalaya, Palampur under the network of All India Coordinated Research Project on Soil Test Crop Response (STCR) Correlation Studies. The experiment consisted of eight treatments (control, general recommended dose, soil test based, farmers’ practice, target yield of 25 (rabi)/30 (kharif) and 35 (rabi)/40 (kharif) q ha^?1 either with or without 5 t ha^?1 farm yard manure) replicated thrice in a randomized block design. All the passive and active pools of soil organic matter (SOM) were highest under STCR treatments for target yield 35 q ha^?1 + farmyard manure (FYM). The highest value of both humic and fulvic acids under STCR treatment for target yield 35 q ha^?1 with FYM was statistically at par with treatment for target yield 25 q ha^?1 with FYM. The R² value indicated that about 96% to 98% of the total variation in grain yield was attributable to SOM fractions. The contribution of all fractions of SOM towards the total variation in straw yield was 96% to 97%.