Characterization of infectious laryngotracheitis virus isolates from laying hens during 2019-2020 outbreaks in Tamil Nadu, India.

Infectious laryngotracheitis (ILT) is an acute respiratory disease in chickens that is a serious threat to poultry-producing countries worldwide. In the present study, we isolated and characterized infectious laryngotracheitis (ILTV) virus isolates by sequencing and restriction fragment length polymorphism analysis of PCR-amplified products (PCR-RFLP). A total of 26 ILTV outbreaks were investigated that occurred between 2019 and 2020 in flocks that had not been vaccinated against ILTV. ILTV was isolated by cultivating tracheal samples in embryonated chicken eggs, which showed multiple opaque pock lesions and thickening of the chorioallantoic membrane after 120 hours of infection. The ILTV isolates were identified and characterized by PCR and sequencing a portion of the ICP4 and TK genes. Phylogenetic analysis based on the ICP4 region showed that the sequences clustered with chicken-embryo-origin vaccine-like strains. Sequence analysis of the ICP4 region differentiated chicken-embryo-origin (CEO), tissue-culture-origin (TCO), and field ILTV strains, with significant differences in nucleotide and amino acid sequences. Furthermore, PCR-RFLP analysis of the TK gene showed that the patterns were identical to those obtained with low-virulence and vaccine strains. In conclusion, sequencing of a portion of the ICP4 region of ILTV allowed differentiation of ILTV field, CEO, and TCO vaccine strains. In this study, CEO-vaccine-like strains were found to be the cause of ILTV outbreaks between 2019 and 2020 in Tamil Nadu in southern India.

Therapeutic antigout and antioxidant activity of Piper betle L. in gout-induced broilers.

1. The following trial investigated the antigout activity and probable mechanism of Piper betle L. herb in gout-induced broiler chickens. The antioxidant and production performance modulating activity of P. betle L. was compared against the standard antigout drug Allopurinol.2. One hundred and sixty, one-day-old female chicks were randomly divided into five treatment groups (control, gout challenged, Allopurinol, P. betle 20 g/kg and P. betle 25 g/kg of feed) with eight birds per group (four replicates) and fed over six weeks. Gout was induced using sodium bicarbonate in water (20 g/l). The clinical signs of gout and production performance were recorded and gross and histopathology was conducted on dead birds. Serum uric acid and creatinine were estimated (on d 10, 14, 17, 19, 21 and 42) and antioxidant and xanthine oxidase enzyme activities were measured from blood samples.3. Uric acid progressively reduced after treatment with P. betle 20 g/kg from d 17 (19.4 ± 0.62 mg/dl) to d 21 (9.81 ± 0.3 mg/dl) and xanthine oxidase activity was likewise suppressed (7.80 ± 0.04 U/mg protein), in a similar manner to Allopurinol (7.75 ± 0.05 U/mg protein), which authenticated the mechanism of antigout activity. Better feed conversion ratios (1.83 ± 0.001) and the restoration of the antioxidants superoxide dismutase, catalase and glutathione to normal levels were observed from birds fed P. betle 20 g/kg than with Allopurinol.4. The data showed that P. betle can be an effective treatment for gout in broiler chicken, as an alternative to Allopurinol.

Molecular typing and pathogenicity assessment of fowl adenovirus associated with inclusion body hepatitis in chicken from India.

Recently, inclusion body hepatitis (IBH) outbreaks have been increasingly reported in different regions of India, particularly in broiler flocks. The present study was undertaken to characterize fowl adenovirus associated with IBH in chicken and assessment of its pathogenicity. Liver samples were collected from fowl adenovirus (FAdV) suspected 100 commercial broiler and six broiler breeder flocks from eleven different States of India from 2016 to 2019. All the samples were subjected to 897-bp FAdV hexon gene-specific PCR for confirmation and primary chicken liver cells were used to isolate the field FAdVs. Sequencing and phylogenetic analysis of 897-bp FAdV hexon gene revealed that all the isolates have showed close evolutionary relationship with fowl adenovirus serotype 11 of species D. For pathogenicity assessment, 0.5 ml of 106.5 TCID50/ml of field FAdV serotype 11 isolate was orally inoculated in 1-day-old SPF chicks and observed for 21 days. This experimental study revealed that there was no mortality in infected chicks and showed clinical signs of dullness, depression and diarrhoea between third and fifth day of oral inoculation. The FAdV was reisolated and confirmed by PCR from experimentally infected chicken. Based on this study, among all serotypes, FAdV serotype 11 is involved in pathogenesis of inclusion body hepatitis in broiler-type chickens in India.

Herd-level risk factors for bovine viral diarrhea infection in cattle of Tamil Nadu.

A cross-sectional study was carried out to identify risk factors for bovine viral diarrhea virus (BVDV) infection in 62 randomly selected dairy herds which were tested for BVD serum antibodies by using an indirect ELISA kit (IDEXX). Results from the chi-square test analysis were interpreted by analyzing by chi-square test. A sum of 500 sera samples were screened and 66 animals (13.20%) showed positive for BVDV antibody. Within herd, BVD seroprevalence was 12-65%. This study concluded that epidemiological risk factors like location, herd size, housing patterns like, tail to tail system, roofing pattern, distance between the manure pit and farm, and distance between farms were significantly associated with BVDV serological status (P < 0.05).

Complete nucleotide sequence analysis of the oncogene "Meq" from serotype 1 Marek's disease virus isolates from India.

1. A study was undertaken to characterise the oncogene Meq at the molecular level for three serotype 1 Marek's disease virus (MDV) field isolates from vaccinated poultry flocks which had encountered a Marek's disease outbreak in the southern part of India. The isolates were named Ind/TN/11/01, Ind/KA/12/02 and Ind/TN/12/03. The oncogene Meq was amplified by PCR and sequenced. 2. The isolates were shown to have a homology for the Meq gene of 99.1-99.8% with various isolates from China and 98.5-99.2% with isolates from Europe and the USA. Alignment analysis of the nucleotide sequences showed that nucleotide mutations at 5 different positions in the Meq gene displayed perfect regularity in MDVs circulating in the southern part of India, which could be considered as features of field MDVs recently prevalent in this area. 3. In addition, the mutation in the Meq gene at positions 251, 260 and 437 was unique and coincides with very virulent strains from China GX0101, GXY2 and a Hungarian strain ATE. The mutation at positions 283 and 300 was unique and coincides with the very virulent strain ATE of Hungary. There were also single nucleotide mutations at positions 155 (A-T), 369 (A-C), 462 (C-A) and 548 (C-T) observed in the isolate Ind/TN/12/03. 4. Phylogenetic analysis of Meq sequences revealed that field MDVs in this area evolved independently but have similarities with very virulent strains from China, and that Meq has more similarities with the very virulent Hungarian strain.

Studies on the effectiveness of oral pellet vaccine in improving egg production and egg quality in desi chicken.

AIM: To study the effect of Newcastle disease (ND) oral pellet vaccine in egg production and egg quality in desi chicken. MATERIALS AND METHODS: The study was conducted at Veterinary University Training and Research Centre, Tiruchirapalli, Tamil Nadu. A total of 48-day-old desi chicks obtained from a private hatchery in Namakkal, Tamil Nadu, were maintained under cage system of rearing up to 52 weeks of age as per standard management practices. All the 48 chicks were divided into six groups having eight chicks in each group were subjected to different treatment regimes. All the birds were challenged at 52 weeks of age with 0.5 ml dose of 10(4.0) egg infectious dose 50 virulent ND field virus. 10 eggs from each group were randomly collected during the last 3 days of 8 weeks interval period from 28 to 52 weeks of age and were used to measure the egg quality parameters. The production performance of each group was assessed at 4 weeks interval period from 25 to 52 weeks of age. RESULTS: In all the six treatment groups with respect to egg production, no significant difference (p≥0.05) was noticed from 25 to 52 weeks of age. Similarly, in egg weight, egg shape index and specific gravity, no significant difference (p≥0.05) was noticed from 28 to 52 weeks of age. CONCLUSION: From this study, it is concluded that the administration of ND oral pellet vaccine to desi chicken does not affect the egg production performance, egg weight, egg shape index, and specific gravity of egg.

Pathotyping of recent Indian field isolates of Marek's disease virus serotype 1.

A study was undertaken to assess the virulence of Marek's disease virus (MDV) serotype 1 field isolates obtained from poultry flocks of southern part of India. Five representative MDV serotype 1 strains were isolated from eighty-six blood samples collected from fifteen farms. Three out of five isolates which were free from avian leukosis virus (ALV) and reticuloendotheliosis virus (REV) were adapted in chicken embryo fibroblast (CEF) culture and designated as Ind/TN/11/01, Ind/KA/12/02 and Ind/TN/12/03. Pathotyping assay was conducted in two trials. In the first trial, non-vaccinated chickens were challenged (trial I), while in second trial, two types of vaccinated chickens along with non-vaccinated controls were challenged (trial II). Birds inoculated with field isolate Ind/TN/12/03 had very low body (75.34 ± 3.04 g 15 days post infection (dpi)) and bursa Fabricii weight (1.64 ± 0.06 at 15 dpi) when compared to those inoculated with the other two isolates (Ind/TN/11/01 and Ind/KA/12/02) and uninoculated controls (body weight 111.33 ± 1.30 g and bursa Fabricii weight 4.33 ± 0.11 15 dpi). Incidence of early mortality syndrome (53%) and lymphoma (86%) induced by Ind/TN/12/03 was comparable with very virulent strains published elsewhere. In protection test, the percentage of Marek's disease (MD) incidence induced by Ind/TN/12/03 was 57.5% and 25% in monovalent and bivalent vaccine inoculated birds respectively compared to uninoculated control (100%). Based on the above findings in pathotyping experimental trials with a supportive evidence of histopathological observations, isolate Ind/TN/12/03 was considered as very virulent MDV and other two isolates were considered as virulent MDVs.

Optimisation of in silico derived 2-aminobenzimidazole hits as unprecedented selective kappa opioid receptor agonists.

Kappa opioid receptor (KOR) is an important mediator of pain signaling and it is targeted for the treatment of various pains. Pharmacophore based mining of databases led to the identification of 2-aminobenzimidazole derivative as KOR agonists with selectivity over the other opioid receptors DOR and MOR. A short SAR exploration with the objective of identifying more polar and hence less brain penetrant agonists is described herewith. Modeling studies of the recently published structures of KOR, DOR and MOR are used to explain the receptor selectivity. The synthesis, biological evaluation and SAR of novel benzimidazole derivatives as KOR agonists are described. The in vivo proof of principle for anti-nociceptive effect with a lead compound from this series is exemplified.

Therapeutic management of botulism in dairy cattle.

AIM: To report the successful recovery of few dairy cattle from botulism in response to a modified therapeutic strategy. MATERIALS AND METHODS: Seventy four naturally-occurring clinical cases of bovine botulism encountered during the period of 2012-2014 which were confirmed by mouse lethality test became material for this study. Affected animals were made into three groups based on the treatment modifications made during the course of study. RESULTS AND DISCUSSION: With the modified therapeutic regimen, 17 animals recovered after 7-10 days of treatment. Clinical recovery took 2-30 days. Animals which were not given intravenous fluid and calcium recovered uneventfully. Cattle which were already treated with intravenous fluids, calcium borogluconate, and antibiotics did not recover. They were either died or slaughtered for salvage. CONCLUSION: In cattle with botulism, administration of Vitamin AD3E and activated charcoal aid the clinical recovery. Besides, strictly avoiding anti-clostridial antibiotics, fluid therapy, and calcium therapy may facilitate the clinical recovery. Upon fluid administration, the pulmonary congestion existed in the ailing cattle might have worsened the anoxia. Administration of antibiotics like penicillin, aminoglycosides, and tetracyclines further worsen the neuronal paralysis by increasing the availability of botulinum neurotoxin. Cattle in early botulism have fair chances of recovery with the modified therapy.

Botanical derivatives in mosquito control: a review.

A review on the reported uses of chemicals derived from botanical sources is presented, along with the part of the plant used for extraction, the mosquito species studied and the bioactivity observed for 344 plant species. Examples of phytochemicals evaluated against mosquitoes as general toxicants, growth and reproduction inhibitors, repellents and ovipositional deterrents are given. The effects of mosquito species and life stage specificity, solvents used for extraction, phototoxic activity and the geographical source from where the plant compounds are derived are discussed.