| characterization by restriction fragment length polymorphism and sequence analysis of field and vaccine strains of infectious laryngotracheitis virus involved in severe outbreaks. | at the end of 2002 and throughout 2003, there was a severe outbreak of infectious laryngotracheitis (ilt) in an intensive production area of commercial hens in the sao paulo state of brazil. ilt virus was isolated from 28 flocks, and 21 isolates were genotyped by polymerase chain reaction and restriction fragment length polymorphism (pcr-rflp) using four genes and eight restriction enzymes, and by partial sequencing of the infected cell protein 4 (icp4) and thymidine kinase (tk) genes. three gro ... | 2010 | 21154050 |