Immune Responses Induced in Chickens by Capsular Extract of P. Multocida Isolated From Farm Rat

An experiment was conducted to investigate the immune response induced in chickens by capsular extract of Pasteurella multocida isolated from rats wandering in and around the poultry farms. The rat isolate of P. multocida was isolated and identified by cultural, morphological, and biochemical characteristics, followed by capsular extract preparation and experimental vaccine development. The isolated P. multocida was found Gram-negative, non-motile, non-spore forming rod occurring singly or pains and occasionally as chains or filaments in Gram’s-staining method. The isolates consistently produced acid from dextrose, sucrose and mannitol but not fermented maltose or lactose. The Capsular antigen was extracted and confirmed by acriflavine test. Finally, experimental fowl cholera vaccine was prepared. Primary vaccination was performed at the dose rate of 5.6×107 CFU/ml through intramuscular and subcutaneous routes in birds of group A (10 birds) and group B (10 birds) and group C (10 birds) were control birds. Secondary vaccination was similarly performed after 15 days of primary vaccination in groups A and B. The levels of pre-vaccination and post-vaccination sera were determined by passive haemagglutination test. The passive haemagglutination antibody titre was recorded on 15 and 35 days of post vaccination in groups A and B. It was demonstrated that experimental capsular extract fowl cholera vaccine conferred 100% protection (p<0.01) against challenge infection and found to be safe. It could be suggested that after thorough field trial, the experimentally prepared capsular extract FC vaccine using rat isolate of P. multocida may be used side by side with conventional FC vaccine. Res. Agric., Livest. Fish.8(1): 117-124, April 2021

Measles immunity in different population groups

Objective: to examine the state of the immunity to measles in different age groups.Materials and methods: In 2018, 4444 people were examined at the Diagnostic Center (virological). Among them, 3783 people were examined using the passive haemagglutination test for measles (manufactured by Pasteur Research Institute of Epidemiology and Microbiology, Russia). In the remaining 661 cases, the IgG to measles were detected using the enzyme-linked immunosorbent assay (ELISA) by VektoMeaseles IgG test (manufactured by Vector-Best, Russia). The correlation between the measles IgG level (ELISA) and the age was examined in 518 patients. Results: In this study, the immunity to measles was shown to be insufficient in all groups of observed people. Even among medical staff, nearly 10% had no protective level of measles antibodies. We have shown that the correlation between the measles IgG level and the age is statistically significant, so that the number of seronegative persons in different age groups differs significantly. Conclusion: The highest ratio of seronegative individuals was found in the age group between 18 and 25 years (52,33%), which can lead to serious measles outbreaks. Hence, this study confirms a strong need for additional immunization in all groups and especially in young population.

IMMUNE RESPONSE CAPABILITY OF `SHUVRA’ CHICKEN

The study was carried out to determine the humoral immune response to Newcastle Disease Virus (NDV) and Bangladesh Agricultural University Fowl cholera (BAUFC) vaccines in Shuvra chicken, a newly develop chicken strain by BLRI (Bangladesh Livestock Research Institute). Ten Shuvra chickens were vaccinated with Baby Chick Ranikhet Disease Vaccine (BCRDV) at day 7 through intra ocular route (i/o) and with Ranikhet Disease Vaccine (RDV) at day 35 through intramuscular (i/m) route. Vaccine induced serum Haemagglunination Inhibition (HI) antibodies were measured by HI test. Two weeks after final immunization all vaccinated and control Shuvra chickens were challenged with virulent field isolates of NDV where all the vaccinated birds survived without showing any typical signs of NDV during the period of ten days observation period and all the control chickens died. Another 10 Shuvra were vaccinated twice with BAUFC vaccine through intramuscular route at day 42 and 70, and 10 Shuvra chickens were kept as unvaccinated control. This vaccine also induced significantly higher level of antibody titre as determined by Passive Haemagglutination (PHA) test. Vaccinated chickens showed significantly higher survival (80%) following challenge with virulent fowl cholera isolate and all the control birds died within 10 days of observation period. DOI: http://dx.doi.org/10.3329/bjvm.v10i1-2.15639Bangl. J. Vet. Med. (2012). 10 (1&2): 1-7

ISOLATION AND CHARACTERIZATION OF INFECTIOUS LARYNGOTRACHEITIS VIRUS IN LAYER CHICKENS

The present research work was conducted for the isolation and characterization of infectious laryngotracheitis (ILT) virus in layer chickens from commercial farms of Gazipur District. A total of 25 field samples were collected from suspected layer chickens of five commercial farms and were cultivated into 10-12 days old embryonated chicken eggs through chorioallantoic membrane (CAM) route for isolation of field virus. The field viruses were characterized by physico-chemical properties against pH, heat, ether and chloroform, serological test such as virus neutralization test (VNT) and passive haemagglutination (PHA) test and pathogenicity testing. In the embryonated chicken eggs, virus produced discrete pock lesions as early as 2 days of post inoculation and embryo death was recorded within 4-6 days of inoculation. The viruses could be inactivated by pH 4 within 2 hours. Inactivation of viruses was observed at 600C for 6 minutes, 550C for 15 minutes and 380C for 2 days. Ether-chloroform treatment also inactivated the viruses. Virus neutralization test revealed that all the virus isolates were neutralized by antiserum to ILT vaccine. Passive haemagglutination test showed that the tanned sheep RBC sensitized with the virus isolates were agglutinated in presence of the antiserum to ILT vaccine. The pathogenicity test recorded 100% mortality in experimental chickens. Data of this study suggest that the field isolates might be infectious laryngotracheitis virus.DOI = http://dx.doi.org/10.3329/bjvm.v8i2.11194 Bangl. J. Vet. Med. (2010). 8 (2) : 123-130

The Isolated and Purified β-lactamase from Local Isolate of Staphylococcus aureus

β-lactamase was isolated from a local isolate of Staph. aureus, which elicited its resistance to penicillin–G, and rapid β-lactamase production. β-lactamase has been purified by using gel-filtration chromatography in Sephadex G–100 column. The molecular weight of purified β-lactamase was estimated by SDS-poly acrylamide gel electrophoresis and shown one band protein with molecular weight of 30 kDa. The antiserum was prepared for purified β-lactamase in rabbits, the measurements of antibodies titer were done by using passive haemagglutination test and it equaled to 40960, which indicated the immunogenicity of purified β-lactamase. The neutralization of β-lactamase activity by antiserum was performed in vitro, so Staph. aureus isolates regained their sensitivity to penicillin–G.