Study the effect of mycoplasmae contamination of eggs on virus titration and efficacy of some poultry vaccines

Abstract

So it was planed firstly in Experiment 1 to clarify the effect of the interaction between M. gallisepticum and evaluation of some inactivated poultry viral vaccines (NDVV, AIVV, IBVV, IBDVV and Reo VV) to show its effect on their titration and efficacy in infected chickens. The results achieved by vaccination of 20 groups of chicks (25 chicks per group) with inactivated viral vaccines mentioned previously. For each vaccine group of chicks was experimentally pre-infected with MG strain then vaccinated, group was infected with MG strain and simultaneously vaccinated, in addition to a group was infected with MG strain 5 days after vaccination, while the last group was only vaccinated.

Secondary in Experiment 2 to study the effect of M. gallisepticum contamination in SPF eggs on virus titration of some live attenuated poultry viral vaccines (NDVV, IBVV, IBDVV and Reo VV). The results achieved by inoculation of M. gallisepticum (pre, simultaneously and post inoculated with those live attenuated vaccines in 800 ECE each vaccine serially diluted from 10-1 to 10-12 for NDVv10-1 to 10-8 for other vaccines respectively, each dilution inoculated in five EC SPF eggs. Finally to Emphasize the importance of using Mycoplasma-free eggs and chicks for the production and evaluation of different types of poultry viral vaccines.

Experiment 1 showed the following: The highest titer of ND antibodies using HI test at the 28 days post vaccination in Mycoplasma pre-infected group was 7.4 Log2 while the lowest titers were recorded in ND vaccinated non infected group (6.5 Log2). The protection percentage against NDV among Mycoplasma pre and post-infected ND vaccinated groups were 100% while simultaneously Mycoplasma infected and non infected ND vaccinated group was 90%. The highest titer of AI antibodies using HI test at the 28 days post vaccination in Mycoplasma pre-infected group was 7.1Log2 while the lowest titers were recorded in AI vaccinated non infected group 6.5 Log2. The protection percentage against AIV among Mycoplasma pre and post-infected AI vaccinated groups was 100 % while in simultaneously Mycoplasma infected and non infected AI vaccinated group was 90%. The highest titer of IB antibodies by ELISA test at the 28 days post vaccination in Mycoplasma pre-infected group was 20 EU while the lowest titers were recorded in IB vaccinated non infected group 12 EU. The protection percentage against IBV among Mycoplasma pre infected IBV vaccinated group was100% and was the most protected group compared with the other groups. The highest titer of IBD antibodies by ELISA test at the 28 days post vaccination in Mycoplasma pre-infected IBD vaccinated group was 20 EU while the lowest titers were recorded in Mycoplasma simultaneously infected IBD vaccinated group 14 EU. The protection percentage against IBDV among Mycoplasma non-infected IBD vaccinated group was 90% and it was the lowest protected group compared with the other groups. The highest titer of Reo antibodies by ELISA test at the 28 days post vaccination in Mycoplasma pre-infected Reo vaccinated group was 17EU while the lowest titers were recorded in Reo vaccinated non infected group. The protection percentage against Reo virus among Mycoplasma pre-infected Reo vaccinated group was the most protected group (100%) compared with the other groups. Results of Experiment 2 showed that: The highest titer of ND virus by HA test applied on allantoic fluid of ECE was appeared in Mycoplasma pre-contaminated group (1011) while the lowest titers were recorded in ND inoculated without MG contamination group(108). The highest titer of ND antibodies by HI test at the 28 days post vaccination in Mycoplasma pre-infected group was 7.5 Log2 while the lowest titers were recorded in ND vaccinated non infected group (6.5 Log2). The protection percentage against NDV among Mycoplasma pre-infected ND challenged group was 100%. Lower than it simultaneously and post Mycoplasma infected groups 95%. The non infected ND challenged group recorded lowest protection percent (90%). The highest titer of IB virus was appeared in Mycoplasma pre-contaminated group (107.5) while the lowest titers were recorded in IBV inoculated without MG contamination group (106). The potency test of IBV recorded that the highest titer of IB antibodies by ELISA test among the collected serum at the 28 days post inoculation was in Mycoplasma pre-infected group (36 EU)while the lowest titers were recorded in IB inoculated without MG infected group(12EU).