Pathological Diagnosis and Genomic Characterization of ICP4 Gene of lnfectious Laryngotracheitis Virus (ILTV) Isolates in Clinically Infected Chicken in Tamil Nadu, India

Background: Infectious laryngotracheitis (ILT) is an economically important viral respiratory disease in poultry. Recently, re-emergence of Infectious laryngotracheitis virus (ILTV) has been reported in several countries including India. The current study aimed to evaluate the poultry flocks of Tamil Nadu with circulating GaHV-1 and to elucidate the origin of the virus involved in the outbreak. Methods: In this study, a molecular based survey on the overall occurrence of natural cases of Infectious laryngo-tracheitis in poultry flocks from Tamil Nadu, India were performed. Pathological findings in respiratory and secondary lymphoid organs like caecal tonsils and harderian gland was carried out. The PCR technique targeting Infected Cell Protein-4 (ICP4) gene along with molecular characterization was performed. Result: The overall prevalence rate in the outbreak was 42.86% with highest incidence in layer flocks (62.85%) than the broiler flocks (22.85%). The highest susceptible age groups were between 20-30 weeks old. Tracheal pathology revealed epithelial sloughing, syncytial cell formation, eosinophilic intranuclear inclusion bodies and heterophilic exudation microscopically. Partial genome sequencing and phylogenetic analysis of ICP4 gene revealed high genetic homology between field isolates and the virulent strains from Turkey, Germany, China and Brazil. In the present study, along with pathological findings, a rapid and sensitive PCR assay was used for detection of ILT virus specific ICP4 gene in commercial poultry farms in the region.

Route of infectious bronchitis virus vaccination determines the type and magnitude of immune responses in table egg laying hens

Chicken immune responses to infectious bronchitis virus (IBV) vaccination can depend on route of administration, vaccine strain and bird age. Typically for layer chickens, IBV vaccinations are administered by spray in the hatchery at day-old and boosted at intervals with live vaccines via drinking water (DW). Knowledge of live attenuated IBV vaccine virus kinetics and the immune response in egg-laying hens is exceptionally limited. Here, we demonstrated dissemination of vaccine viruses and differences in hen innate, mucosal, cellular and humoral immune responses following vaccination with Massachusetts or 793B strains, administered by DW or oculonasal (ON) routes. Detection of IBV in the Mass-vaccinated groups was greater during early time-points, however, 793B was detected more frequently at later timepoints. Viral RNA loads in the Harderian gland and turbinate tissues were significantly higher for ON-Mass compared to all other vaccinated groups. Lachrymal fluid IgY levels were significantly greater than the control at 14 days post-vaccination (dpv) for both vaccine serotypes, and IgA mRNA levels were significantly greater in ON-vaccinated groups compared to DW-vaccinated groups, demonstrating robust mucosal immune responses. Cell mediated immune gene transcripts (CD8-α and CD8-β) were up-regulated in turbinate and trachea tissues. For both vaccines, dissemination and vaccine virus clearance was slower when given by DW compared to the ON route. For ON administration, both vaccines induced comparable levels of mucosal immunity. The Mass vaccine induced cellular immunity to similar levels regardless of vaccination method. When given either by ON or DW, 793B vaccination induced significantly higher levels of humoral immunity.

Immune response of the harderian gland in chickens to infectious bronchitis coronavirus

Aim. To determine the difference in immune responses of the harderian gland in clinically healthy chickens and the ones with infectious bronchitis based on the content, localization and morphometric estimation of the surface markers of Т- and В-lymphocytes and to determine the differentiation index as an indicator of assessing body defenses. Methods. Histological, immunohistochemical, optical, morphometric and statistical. Results. The histological study of the harderian gland of chickens with infectious bronchitis determined the swelling and proliferation of the connective tissue as well as infiltration of secretory lobules by lymphoid cells. It was found that the immunity of chickens with infectious bronchitis, in which the harderian gland plays a relevant role, depends considerably on the differentiation index of immunocompetent cells. There was a reliable 1.77- and 1.36-fold decrease in this indicator for 40- and 90-day-old chickens, respectively, in case of nephroso-nephritic form of infectious bronchitis which demonstrated a weaker function of the defense cells of this organ. According to the cytomorphometric analysis, the number of cells, expressing CD4+, CD8+, CD20+, CD45RA+ markers in the harderian gland of sick 20-, 40-, and 90-day-old chickens with respiratory and nephroso-nephritic forms of infectious bronchitis was reliably (P < 0.05) increasing compared to the clinically healthy chickens. For instance, the number of mature В-lymphocytes increased in sick 20-day-old chickens – 2.44 times, 40-day-old chickens – 1.88 times, and 90-day-old ones – 2.62 times compared to clinically healthy chickens. Conclusions. The data were obtained about the changes in quantitative and qualitative composition of lymphocytes with surface markers CD4+, CD8+, CD20+, CD45RA+ in the harderian gland of chickens with infectious bronchitis. Our results will supplement current knowledge about the feasibility of immunohistochemical methods in the diagnostics of avian infectious bronchitis.

Evaluation of Mucosal Immunity in Chickens Vaccinated With Oral Pellet Newcastle Disease Vaccine

The Newcastle disease outbreak in chickens is a continuing threat to the poultry industry. Infection with Newcastle disease is greatly influenced by the immune status of the birds. The mucosal immunity plays a major role in the local immune response in the protection of chickens against diseases. This study was undertaken to find the efficacy of thermostable live oral pellet vaccine in developing the mucosal immunity in chickens. Samples were collected from Harderian gland, Lachrymal fluid, Tracheal fluid, Intestinal washings, Bile and Serum of chickens after administration of oral pellet vaccine to detect presence of NDV specific IgA antibodies. Results showed that there is significant increase in the immune response after one week post vaccination with no significant difference between 14 and 21 days after vaccine. There exists significant difference in Mean OD values between samples of Harderian, Lachrymal, Trachea, Intestine, Bile and serum with bile found to have increased IgA response. Challenge experiment results showed that oral pellet vaccine was able to protect chickens against virus challenge by increasing the mucosal immunity against Newcastle disease.

Post Natal Gross Anatomical Studies on the Harderian Gland of Pati Duck (Anas platyrhynchos domesticus) of Assam

Background: The agro-climatic condition of Assam is suitable for duck rearing. Duck rearing contributes a major part to uplift the socio-economic condition of the rural poor people of Assam as well as others states located in the coastal regions of India. The Pati duck (Anasplatyrhynchos domesticus) population constitutes a major indigenous non-descript economically important duck variety in the state of Assam. The Harderian gland acts as a part of the Head Associated Lymphoid Tissue (HALT) Olah et al. (1992) and provides local innate immunity to the upper respiratory system, to the eye and oral cavity. Since literature on the postnatal development of Harderian gland of Pati duck is scant, hence the present study was designed to establish the basic anatomical details on Harderian gland at different stages of postnatal development of Pati duck of Assam. Methods: The present study was conducted on total forty five (45) numbers Pati duck of Assam at different stages of postnatal development. The experimental birds were brought to the Department of Anatomy and Histology, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-22 and was sacrificed according to the method of Gracy (1986). After slaughter, the birds were placed on a clean dissecting table and skin and fascia were reflected carefully without disturbing the other organs of the head region. The Harderian gland was collected by opening the orbital cavity. Thereafter, length, breadth and thickness of the Harderian gland of all age group were recorded with the help of the Vernier Callipers (McCance, 1974) and topographical location of the gland was observed. The weight of the Harderian gland of all age group was also recorded with the help of electronic balance. Result: The Harderian gland of Pati duck (Anas platyrhynchos domesticus) was located within the orbit. The gland was flat, oval and coma shaped with irregular border. The gland had two surfaces i.e. the parietal and visceral surfaces, two borders and two blunt poles. The parietal surface was found convex and attached to fascia covered by the nasal bones and interorbital septa. The visceral surface was concave and it was attached loosely to the eye ball with fascia. The lobes of the Harderian gland became more prominent with the advancement of the age. The gland was light pink in colour. The arterial blood and the venus drainage was by provided by the ophthalmic artery and vein, respectively. The slender branch of oculomotor nerve innervated the Harderian gland. The result reflected an ascending trend from 0 week age group to 42 week age group in regard to all the gross parameters. There were slight difference between left and right glands for all the gross parameters but such variations were not statistically significant (P greater than 0.05). Each lobe of the Harderian Gland of Pati duck (Anas platyrhynchos domesticus) had a single short duct which opened into the conjunctival sac at the base of the 3rd eyelid.

Melatonin Ameliorates Autophagy Impairment in a Metabolic Syndrome Model

Metabolic syndrome is a global health problem in adults and its prevalence among children and adolescents is rising. It is strongly linked to a lifestyle with high-caloric food, which causes obesity and lipid metabolism anomalies. Molecular damage due to excessive oxidative stress plays a major role during the development of metabolic syndrome complications. Among the different hormones, melatonin presents strong antioxidant properties, and it is used to treat metabolic diseases. However, there is not a consensus about its use as a metabolic syndrome treatment. The aim of this study was to identify melatonin effects in a metabolic syndrome model. Golden hamsters were fed with 60% fructose-enriched food to induce metabolic syndrome and were compared to hamsters fed with regular chow diet. Both groups were also treated with melatonin. Fructose-fed hamsters showed altered blood lipid levels (increased cholesterol and LDL) and phenotypes restored with the melatonin treatment. The Harderian gland (HG), which is an ideal model to study autophagy modulation through oxidative stress, was the organ that was most affected by a fructose diet. Redox balance was altered in fructose-fed HG, inducing autophagic activation. However, since LC3-II was not increased, the impairment must be in the last steps of autophagy. Lipophagy HG markers were also disturbed, contributing to the dyslipidemia. Melatonin treatment improved possible oxidative homeostasis through autophagic induction. All these results point to melatonin as a possible treatment of the metabolic syndrome.