Detection of infectious laryngotracheitis virus (ILTV) in tissues and blood fractions from experimentally infected chickens using PCR and immunostaining analyses

Author(s)
Tran, Thanh T
Shahid, Nazir
Yegoraw, Addisu A
Assen, Awol M
Walkden-Brown, Stephen W
Gerber, Priscilla F
Publication Date
2021-01
Abstract
<p>The ability of infectious laryngotracheitis virus (ILTV) to replicate in organs outside of the upper respiratory tract and conjunctiva associated-lymphoid tissues is still not well understood. This study investigated the tissue distribution of an Australian field strain of ILTV (class 9) on birds experimentally inoculated via eye-drop at 7 days of age by using quantitative PCR (qPCR) and immunohistochemistry. Tissues including conjunctiva, caecal tonsil, kidney, liver, lung, spleen, thymus, trachea and blood were collected from sham-inoculated (control group; <i>n</i> = 2) and ILTV-inoculated (<i>n</i> = 8) birds at 7 days post-inoculation (dpi). Blood was collected from 13 infected birds at 14 dpi and fractionated using ficoll-paque. At 7 dpi, the highest detection rate and genomic copies (GC) were in conjunctiva (8/8; 8.08 ± 0.48 log<sub>10</sub> GC/mg) followed by trachea (8/8; 4.64 ± 0.48) and thymus (8/8; 4.52 ± 0.48), kidney (8/8; 3.97 ± 0.48), lung (8/8; 3.65 ± 0.48), spleen (8/8; 3.55 ± 0.48), liver (8/8; 3.51 ± 0.48), caecal tonsil (7/8; 3.76 ± 0.48) and plasma (4/8; 2.40 ± 0.48 log<sub>10</sub> GC/ml). ILTV antigen was only detected in conjunctiva (7/8), trachea (6/8) and lung (4/8) samples. At 14 dpi, ILTV detection rate and genomic copies in buffy coat cells were 12/13 and 2.86 ± 0.39 log<sub>10</sub> GC/mg, respectively while those of plasma were 11/13 and 4.29 ± 0.39 log<sub>10</sub> GC/ml and red blood cell were 3/13 and 0.36 ± 0.39 log<sub>10</sub> GC/mg. In conclusion, ILTV DNA was detected in a wide range of tissues and blood fractions but ILTV antigen was only detected in respiratory organs and conjunctiva.</p>
Citation
Research in Veterinary Science, v.134, p. 64-68
ISSN
1532-2661
0034-5288
Pubmed ID
33310555
Link
Publisher
Elsevier Ltd
Title
Detection of infectious laryngotracheitis virus (ILTV) in tissues and blood fractions from experimentally infected chickens using PCR and immunostaining analyses
Type of document
Journal Article
Entity Type
Publication

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