Molecular detection and characterization of infectious laryngotracheitis virus in backyard chickens in Turkey

Abstract

Gallid herpesvirus I (GaHV1) is etiological agent of infectious laryngotracheitis (ILT) and ILT is one of the important disease that included in respiratory infections of chickens. Few studies have been conducted in Turkey and there is no data about the existence of ILT in backyards. The purpose of the study was to document the detection and characterization of GaHV1 in backyard chickens using PCR, RFLP and sequencing. Of the163 tracheal swap samples which were taken from 43 backyard flocks 5 (3.07%) were found to be positive for ILT infection. Positivity was 4.65 % (2/43) at flock level. The nucleic acid sequences of the ICP4 gene compared with ILTV sequences in GenBank and the level of identity differed from 96.82 to 100%. When the sequences of samples compared with TCO strains 99.77-100% homology was observed. The virtual RFLP analysis with the HgaI restriction enzyme characterized strains as having a pattern similar to the vaccine strain TCO. This is the first study that presents presence and characterization of GaHV1 in backyards. Large scale studies are needed to estimate prevalence of ILT in Turkey. Chickens should be monitored and growers should avoid to contacting vaccinated birds with non-vaccinated chickens, to control ILTV outbreaks.