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

Tran, Thanh T; Shahid, Nazir; Yegoraw, Addisu A; Assen, Awol M; Walkden-Brown, Stephen W; Gerber, Priscilla F

doi:10.1016/j.rvsc.2020.11.024

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

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; n = 2) and ILTV-inoculated (n = 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 log10 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 log10 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 log10 GC/mg, respectively while those of plasma were 11/13 and 4.29 ± 0.39 log10 GC/ml and red blood cell were 3/13 and 0.36 ± 0.39 log10 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.

Citation

Research in Veterinary Science, v.134, p. 64-68

ISSN

1532-2661

0034-5288

Pubmed ID

33310555

Link

https://hdl.handle.net/1959.11/51882

Language

en

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

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	https://hdl.handle.net/1959.11/51882
Language	en
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

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

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