Clinico-Pathological And Pathomorphological Studies On Co-Infection Of Avian Influenza (H9n2) With Escherichia Coli In Broiler Chicken
Material type: Book ; Literary form:
Publisher: 2016 Dissertation note: E.coli is an important pathogen of domestic poultry and is prevalent in commercial poultry. LPAIV H9N2 infections are emerging respiratory problems in poultry industry, causing huge economic losses especially in the presence of other co-infecting pathogens such as E.coli. Co-infections do occur but are not easily detected, and the impact of co-infections on pathobiology is unknown. The mixed infections may provide increased virulence, posing a substantial risk to poultry and public health. Moreover, mixed infections of low pathogenic avian influenza with bacteria can also lead to devastating pandemics and a major threat to poultry health, worldwide in future. Co-infections do occur but are not easily detected, and the impact of co-infections on pathobiology is unknown. The mixed infections may provide increased virulence, posing a substantial risk to poultry and public health. Moreover, mixed infections of low pathogenic avian influenza with bacteria can also lead to devastating pandemics and a major threat to poultry health, worldwide in future. The aim of the present study was to investigate the infection of LPAIV A/chicken/Pakistan/10RS3039-284-48/2010 (H9N2) in chickens challenged with E.coli (O78:K80).
This study had three objectives. First, it is designed to develop co-infection experimental models LPAIV (H9N2) + bacteria (E.coli) in the avian model. Second, it aims to study the hematological and biochemical alterations during co-infection in avian model. Finally to study the pathological and histological alterations during co-infection in avian model, this study will help researchers and veterinarians in implementation of necessary control measures. E.coli stockculture was prepared by inoculating MacConkey’s agar with a loop full of reference E.coli strain culture and incubating at 37°C for 24 h. The estimated colony count was confirmed by plating 0.1 ml of a 104 and a 105 dilution of the final culture onto separate MacConkey’s agar plates. Avian influenza A virus, A/chicken/Pakistan/10RS3039-284-48/2010 (H9N2) was obtained from Poultry Research Institute (PRI) Rawalpindi Pakistan.
Viral stocks were prepared and titrated in 9-day-old to 10-day-old chicken embryonated eggs the median embryo infectious dose (EID50) was computed using previously reported approaches The viral stocks were diluted in medium containing antimicrobials to give a final titre of 106 EID50/ ml The study were ran on 80 broiler chicks (3week old), procured from local hatchery. All fowl were held serologically innocent and free from flu virus by haemagglutination inhibition (HI).
Chicken were infected under experimental conditions with E.coli (O78:K80) and low pathogenic avian influenza (LPAI) strain (A/chicken/Pakistan/UDL-01/08) (H9N2) alone or in combination. The experimental groups were identified as follows: negative control, E.coli, AI, and E.coli plus AI. Infected birds showed clinical signs of differing severity, with the most prominent disease signs appearing in birds of the E.coli plus AI group. Moreover, birds in E.coli plus AI group showed significant decrease in weight, enhanced macroscopic and microscopic pathological lesions. Specifically, the survival rate was 60%, 90%, and 100% in birds inoculated with E.coli + AI, E.coli and control negative or AI virus alone, respectively. Hematological studies revealed anemia, thrombocytopenia and leukopenia especially in co-infected birds. Biochemical studies revealed a significant decrease in total protein, glucose and albumin concentration with significant increase of activities of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. Prominent increase in creatinine, urea and uric acid were significantly detected in the infected chicken. The results showed that experimental co-infection of E.coli and H9N2 increased the severity of clinical signs, mortality rate and gross lesions and suggest than E.coli infection can induce higher economic losses and mortality if H9N2 LPAIV is also present. The HI titer against LPAIV infection in the co-infected group was significantly higher than the HI titer of AI group, which may indicate that E.coli could promote the propagation of H9N2 LPAIV or stimulate the immune response. The present study revealed that co-infection E.coli and H9N2 LPAIV caused more serious synergistic pathogenic effects and indicates the role of both pathogens as complicating factors in poultry infections.
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Immunomodulatory Effects Of Feeding Allium Sativum Against Infectious Bursal Disease (IBD) Vaccinated Broiler Birds On IBD Vaccine.
Material type: Book ; Literary form:
Publisher: 2016 Dissertation note: A number of feed additives including antibiotics have been extensively used in
poultry diets for the purpose of weight gain to improve feed efficiency and growth rate.
However, use of antibiotics has restricted due to the bacterial resistance and the issue of
residues which make the chicken meat harmful for human consumption. So the medicinal
plants are gaining interest as alternative feed strategies now a day because of their low cost,
easy availability and presence of no residues. Garlic was used for the medicinal purposes and
as a health supplement by the ancient Egyptians. It is a natural feed additive and is
antimicrobial, immune stimulator, antiviral, antifungal, anti-parasitic, antithrombotic,
antioxidant, anti-cancerous, and vasodilator activities. Previous studies indicate that it has
beneficial effects on the immune system and is a best immune stimulator then the other
herbal plants and medicines.
Therefore, the present study was designed to estimate the immunomodulatory effect
of garlic to commercially available IBD vaccine in enhancing the immune system. Total
N=99 day old broiler chicks were purchased and kept in the experimental shed of CVAS
Jhang. Birds were divided into three groups A, B, C and group B and C were further divided
into three subgroups (B1, B2, B3 and C1, C2, C3). Group A was treated as control group and
was administered with commercially available IBD and ND vaccine and routine diet while
group B was administered with garlic at the rate of 4%, 5%, and 7% along with vaccine to see
the impact of different levels of garlic (Allium sativum) on the immune system and to see the
toxic effect (if any) of high dose of garlic. Group C was only administered with garlic in fee
at the same rate as to group B. At the end of study birds were slaughtered to check the effects
of garlic administration. Positive effect of garlic has been reported by many studies. Garlic is
a medicinal herb used for the prevention and treatment of many diseases, because of having
antiviral, antibacterial and antifungal activities. Also act as a good growth promoting agent
and have beneficial effects on the immune system. Results of the study indicate that
administration of garlic powder in different doses alone and combined with commercial IBD
vaccine have good effects on the growth, blood parameters and the immune system of the
Availability: Items available for loan: UVAS Library [ Call number: 2561-T] (1).