Study on the efficacy and safety of different antigens and oil formulations of infectious coryza vaccines containing an NAD-independent strain of Avibacterium paragallinarum.
نویسندگان
چکیده
The present study was designed to assess and compare three different formulations of the new Onderstepoort infectious coryza (IC) quadrivalent vaccine, which contain an NAD-independent strain of Avibacterium paragallinarum (previously known as Haemophilus paragallinarum), and a commercial IC vaccine, not containing an NAD-independent strain, for their safety and ability to protect chickens of varying ages against virulent challenges with four different serovars of A. paragallinarum, including the NAD-independent strain of the C-3 serovar. Four groups of 140 chickens each were vaccinated at the age of 17 weeks and revaccinated at the age of 19 weeks with each of the four vaccine formulations. A similar sized group of non-vaccinated chickens was used as control. Two rounds of challenge were conducted: a group of chicken in each vaccination group was challenged between 31 and 35 weeks of age, while another group was challenged between 51 and 55 weeks of age. The "in-contact" challenge model was used in this experiment. For each vaccination group, the four challenge strains representing four local serovars were used in each challenge round. The efficacy of the vaccines was compared based on overall protection levels obtained and the duration of protection. The safety of the different vaccines was determined by the severity of post-vaccination reactions. The need for the incorporation of the NAD-independent strain in the vaccine was evidenced by the low protection level against NAD-independent challenge recorded in the group of birds vaccinated with the commercial vaccine. The results obtained confirmed not only the variation in virulence of different South African serovars, with serovar C-3 being the most virulent and serovar B having almost no virulence but also the age related increase in susceptibility. The importance of a suitable formulation of the vaccine is discussed.
منابع مشابه
Efficacy of Combined Vaccine against Salmonellosis and Infectious Coryza in Poultry. J. World Poult. Res., 7 (3): 145-153.;
In the present study, efficacy of two prepared combined vaccines against salmonellosis and infectious coryza in poultry has been studied. Two vaccines were prepared using Salmonella Typhimurium and Enteritidis combined with Avibacterium paragallinarum serovars A, B, and C. one vaccine was adjuvanated with aluminium hydroxide gel and the other adjuvanated with montanide ISA71. The two vaccines w...
متن کاملRetrospective Detection of Avibacterium Paragallinarum Serovar B in Egg Yolk Materials by PCR
Avibacterium paragallinarum is Gram-negative bacteria that cause infectious coryza (IC), an acute respiratory disease of chickens. Despite vaccination of Layer and breeder farms of Iran against IC, they are still experiencing the disease clinically and there is no knowledge of serotypes prevalence of this bacterium in this country. This study designed to determine serovar identity by molecular ...
متن کاملImmunogenicity and haemagglutination of recombinant Avibacterium paragallinarum HagA.
Inactivated vaccines of Avibacterium paragallinarum provide protection and reduce the economic losses caused by infectious coryza. However, inactivated bacterins provide protection only against the Page serovars included in the vaccine. In this study, we investigated the immunological properties of a functional recombinant haemagglutinin protein (rHagA) derived from a Taiwan isolate strain A9 a...
متن کاملDraft Genome Sequence of Avibacterium paragallinarum Strain 221
Avibacterium paragallinarum is the causative agent of infectious coryza. Here we report the draft genome sequence of reference strain 221 of A. paragallinarum serovar A. The genome is composed of 135 contigs for 2,685,568 bp with a 41% G+C content.
متن کاملDetection of Avibacterium paragallinarum by Polymerase chain reaction from outbreaks of Infectious coryza of poultry in Andhra Pradesh
AIM This study was carried out for the detection of Avibacterium paragallinarum from outbreaks of infectious coryza of poultry. MATERIALS AND METHODS The polymerase chain reaction (PCR) was standardized for the diagnosis of infectious coryza by using infectious coryza Killed vaccine, ventri biologicals, Pune as source of DNA of A. paragallinarum. Five outbreaks of infectious coryza from Andhr...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Onderstepoort journal of veterinary research
دوره 76 3 شماره
صفحات -
تاریخ انتشار 2009