Page 95 - Avian Virology: Current Research and Future Trends

88 | Paldurai and Samal

Table 3.2 Continued
Year
APMV first Genome
serotype Prototype strain a isolated length Host species b Disease
Genus Paraavulavirus
APMV-3 APMV-3/parakeet/Netherlands/449/ 1967 16,272 nt Turkey, parakeet and other Encephalitis and high mortality
(APAvV-3) 1975 (Netherlands) psittacines, passerines in psittacine birds; acute
pancreatitis and neurological
signs in passerines, growth
stunting in broilers, respiratory
disease and egg production
problems in turkeys
APMV-4 APMV-4/duck/Hong Kong/D3/1975 1976 15,054 nt Duck, goose, wild waterfowl, An increase in white-shelled eggs
(APAvV-4) (Hong Kong) chicken, cormorant, bean goose, in layers. Inapparent infection in
swan goose, mallard, common commercial ducks
murre, green-winged teal,
northern pintail, white-fronted
goose, ruddy shelduck,
garganey, wood duck, American
green-winged teal, northern
shoveler, emperor goose, teal,
starling, Egyptian goose, wild
bird
a The prototype strains are provided in an even format. A short-name is assigned for each prototype strain (in the parenthesis) and used in this
chapter denote them for convenience.
b Host list provided is based on the GenBank database isolation history and on article references and is not an exhaustive list.
c Numerous well-characterized Newcastle disease virus strains are available, but for genetic analysis strain LaSota (GenBank database accession
number: JF950510) is used in this chapter.
d Genome termini are incomplete.
e Putative APMV serotype awaiting official recognition from the ICTV.

extent of aa sequence relatedness between NDV and other APMV serotypes other than APMV-1 have worldwide distribution but
serotypes did not correlate with the level of cross-protection. For their prevalence is less than APMV-1 in wild bird populations. It
example, NDV is closely related to APMV-9 by the aa sequences is not known whether this observation reflects presence of these
of F (55.3%) and HN (61.7%) proteins (Samuel et al., 2009), but viruses in a specific geographic location or a narrow host range of
APMV-9 provides very little protection against NDV. Whereas these viruses.
the per cent identity of F and HN proteins between APMV-3 and Migratory wild birds play a major role in spreading of APMVs
NDV is 31.4% and 34.9%, respectively (Kumar et al., 2008), but between continents and between hemispheres (Fornells et al.,
the level of protection by APMV-3 is much more than APMV-9. 2013; Muzyka et al., 2014). Cross-over regions of flyways of
These results suggest that the level of cross-protection between wild birds provide unlimited opportunity for intraspecies and
two APMV serotypes may not directly correlate with the identity interspecies transmission of APMV serotypes. Isolation of two
of the aa sequence of the F and HN proteins but depends upon APMVs of similar genetic characteristics from different avian
the similarity of the conformation of the neutralizing epitopes species and in different geographic regions provides evidence
present on F and HN proteins, which are formed by the tertiary for interpopulation and interspecies transmission of APMVs
structure of the proteins. (Muzyka et al., 2014; Yin et al., 2017; Tseren-Ochir et al.,
2018a, b). Although APMVs can be rapidly transmitted between
continents by migratory birds, the host species and the environ-
Geographic distribution ment also play important roles in subsequent establishment of
APMV serotypes other than APMV-1 have been reported from that virus in the local avifauna. For example, analysis of sequences
different parts of the world involving different species of birds. of F gene of 58 APMV-4 strains isolated from different parts of the
Our understanding of geographic distribution of other APMV world showed that, with only a single exception, the phylogenetic
serotypes in different geographic regions is incomplete as reports clades of APMV-4 sequences were monophyletic with respect
of isolation of other APMV serotypes are limited in number. to their continent of origin (North America, Asia and Europe),
Furthermore, there are very few reports of isolation of other suggesting that intercontinental dispersal of APMV-4 is not
APMV serotypes from some continents (South America, Africa, common (Reeves et al., 2016). However, phylogenetic analysis of
and Oceania). Most of the isolations of other APMV serotypes 11 APMV-4 isolates in China showed that all the isolates share
have been made from wild migratory birds which have been a high level of identity with the viruses from Europe, suggesting
sporadic and are often done in the context of other surveillance intercontinental exchange of APMV-4 strains between Asia and
programs, such as avian influenza viruses. It appears that APMV Europe (Yin et al., 2017).