Spread of the newly emerging infectious laryngotracheitis viruses in Australia

Agnew-Crumpton, Rebecca; Vaz, Paola K.; Devlin, Joanne M.; O’Rourke, Denise; Blacker-Smith, Hayley Patricia; Konsak-Ilievski, Barbara; Hartley, Carol A.; Noormohammadi, Amir H.

doi:10.1016/j.meegid.2016.05.023

Cited by 52 publications

(38 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These recombination breakpoints match with a recombination event previously detected in a study of Chinese ILTV strains, in which the K317 vaccine strain was determined to have arisen as a result of recombination between the Serva vaccine strain and virulent WG field strains (29) ( Table 4). Recombination in this genome region (Table 4) has also been detected previously in Australian ILTV field isolates (2,30).…”

Section: Discussionsupporting

confidence: 78%

“…These strains belong to genotype classes 2 and 4, respectively, following the Australian ILTV genotype classification system (35). The V1-99 field strain was isolated from a hen in a commercial layer flock in 1999 and is typical of the predominant field isolates detected during disease outbreaks in Australia up until 2008 (30). The CSW-1 wild type is currently used as a standard laboratory strain in Australia (36,37) and was originally isolated in 1970 from layer birds (38).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Genetic Diversity of Infectious Laryngotracheitis Virus duringIn VivoCoinfection Parallels Viral Replication and Arises from Recombination Hot Spots within the Genome

Loncoman

Hartley

Coppo

et al. 2017

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

Recombination is a feature of many alphaherpesviruses that infect people and animals. Infectious laryngotracheitis virus (ILTV; Gallid alphaherpesvirus 1) causes respiratory disease in chickens, resulting in significant production losses in poultry industries worldwide. Natural (field) ILTV recombination is widespread, particularly recombination between attenuated ILTV vaccine strains to create virulent viruses. These virulent recombinants have had a major impact on animal health. Recently, the development of a single nucleotide polymorphism (SNP) genotyping assay for ILTV has helped to understand ILTV recombination in laboratory settings. In this study, we applied this SNP genotyping assay to further examine ILTV recombination in the natural host. Following coinoculation of specific-pathogen-free chickens, we examined the resultant progeny for evidence of viral recombination and characterized the diversity of the recombinants over time. The results showed that ILTV replication and recombination are closely related and that the recombinant viral progeny are most diverse 4 days after coinoculation, which is the peak of viral replication. Further, the locations of recombination breakpoints in a selection of the recombinant progeny, and in field isolates of ILTV from different geographical regions, were examined following full-genome sequencing and used to identify recombination hot spots in the ILTV genome.IMPORTANCE Alphaherpesviruses are common causes of disease in people and animals. Recombination enables genome diversification in many different species of alphaherpesviruses, which can lead to the evolution of higher levels of viral virulence. Using the alphaherpesvirus infectious laryngotracheitis virus (ILTV), we performed coinfections in the natural host (chickens) to demonstrate high levels of virus recombination. Higher levels of diversity in the recombinant progeny coincided with the highest levels of virus replication. In the recombinant progeny, and in field isolates, recombination occurred at greater frequency in recombination hot spot regions of the virus genome. Our results suggest that control measures that aim to limit viral replication could offer the potential to limit virus recombination and thus the evolution of virulence. The development and use of vaccines that are focused on limiting virus replication, rather than vaccines that are focused more on limiting clinical disease, may be indicated in order to better control disease.

show abstract

Section: Discussionsupporting

confidence: 78%

Section: Methodsmentioning

confidence: 99%

Genetic Diversity of Infectious Laryngotracheitis Virus duringIn VivoCoinfection Parallels Viral Replication and Arises from Recombination Hot Spots within the Genome

Loncoman

Hartley

Coppo

et al. 2017

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

show abstract

“…Four of these SNPs were located in the unique long (UL) region (UL46-UL36-UL8 and UL0), one in the repeat region (ICP4) and one in the unique short (US) region of the genome (US3). Previous studies carried out in our laboratory have shown ILTV recombination events within the UL and IR region [5] and within the US region [6]. Results from this study indicate that ILTV recombination does not appear to occur in any specific location within the genome, but rather recombination events appeared to result in many different patterns of mosaic viruses.…”

Section: Discussionmentioning

confidence: 45%

“…These new field strains have been responsible for widespread outbreaks of disease and also have displaced previously dominant field strains in some regions in Australia [3–5]. More recently, another virulent recombinant virus, class 10 ILTV, has emerged in Australia to become dominant in some poultry producing regions [6]. Recently a review compiling ten years of research has helped to understand the importance of recombination in alphaherpesviruses evolution [7], showing that recombination allows some alphaherpesviruses to persist, evolve, and become more virulent through time [3, 5, 8–12].…”

Section: Introductionmentioning

confidence: 99%

“…Although ILTV recombination has been detected and studied in field conditions through full genome sequencing and sequence analysis of recovered isolates [3, 5, 6, 17], genome recombination of these viruses has not been studied under experimental conditions. In this study we aimed to develop a rapid and simple TaqMan SNP genotyping assay, as an alternative to full genome sequencing and sequence analysis, to detect ILTV recombinants and to study ILTV recombination under experimental conditions in the natural host.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Development and application of a TaqMan single nucleotide polymorphism genotyping assay to study infectious laryngotracheitis virus recombination in the natural host

et al. 2017

Self Cite

View full text Add to dashboard Cite

To date, recombination between different strains of the avian alphaherpesvirus infectious laryngotracheitis virus (ILTV) has only been detected in field samples using full genome sequencing and sequence analysis. These previous studies have revealed that natural recombination is widespread in ILTV and have demonstrated that recombination between two attenuated ILTV vaccine strains generated highly virulent viruses that produced widespread disease within poultry flocks in Australia. In order to better understand ILTV recombination, this study developed a TaqMan single nucleotide polymorphism (SNP) genotyping assay to detect recombination between two field strains of ILTV (CSW-1 and V1-99 ILTV) under experimental conditions. Following in vivo co-inoculation of these two ILTV strains in specific pathogen free (SPF) chickens, recovered viruses were plaque purified and subjected to the SNP genotyping assay. This assay revealed ILTV recombinants in all co-inoculated chickens. In total 64/87 (74%) of the recovered viruses were recombinants and 23 different recombination patterns were detected, with some of them occurring more frequently than others. The results from this study demonstrate that the TaqMan SNP genotyping assay is a useful tool to study recombination in ILTV and also show that recombination occurs frequently during experimental co-infection with ILTV in SPF chickens. This tool, when used to assess ILTV recombination in the natural host, has the potential to greatly contribute to our understanding of alphaherpesvirus recombination.

show abstract

Infectious Laryngotracheitis

Garcı́a¹,

Spatz²

2019

Diseases of Poultry

View full text Add to dashboard Cite

Spread of the newly emerging infectious laryngotracheitis viruses in Australia

Cited by 52 publications

References 29 publications

Genetic Diversity of Infectious Laryngotracheitis Virus duringIn VivoCoinfection Parallels Viral Replication and Arises from Recombination Hot Spots within the Genome

Genetic Diversity of Infectious Laryngotracheitis Virus duringIn VivoCoinfection Parallels Viral Replication and Arises from Recombination Hot Spots within the Genome

Development and application of a TaqMan single nucleotide polymorphism genotyping assay to study infectious laryngotracheitis virus recombination in the natural host

Infectious Laryngotracheitis

Contact Info

Product

Resources

About