Excellent vaccine against IBD can be obtained from the TY2 strain or a substrain of the virus.
Novel IBD virus TY2 strain was separated and its substrain was obtained.
The vaccine strain is a leucine-auxotrophic strain derived from the BCG substrain Pasteur, supplemented for leucine after genetic transformation with the construct pΔK410-hsp60*-SM14.
In contrast, the light output of the resistant substrain does not change or does not change in parallel with the light output of the sensitive substrain, when exposed to the same chemical agent.
The relative difference in photoluminescence between the sensitive and resistive substrain is compared so as to indicate the quantity or presence of the chemical agent.
The light emission of the sensitive substrain decreases in the presence of the specific chemical agent.
For the detection of a specific chemical agent, sensitive and resistant substrains are genetically selected from the same parent strain of photoluminescent microorganisms.