Molecular characterization and genetic diversity of Ornithonyssus sylviarum in chickens (Gallus gallus) from Hainan Island, China

Abstract

BackgroundThe northern fowl mite (NFM), Ornithonyssus sylviarum, is an obligatory hematophagous ectoparasite of birds and one of the most important pests in the poultry industry on several continents. Although NFM poses a serious problem, it remains a neglected pest of poultry in China and other Asian countries. Therefore, a molecular analysis was conducted to provide baseline information on the occurrence, genetic diversity and emergence of NFM in poultry farms from China.MethodsThis study focused on morphological description and identification of adults based on electron microscopy, molecular sequencing of the mitochondrial cox1 gene and phylogenetic analysis. We have also used the DNA sequences of the cox1 gene to study the genetic diversity, population structure and demographic history. The neutrality tests were used to analyze signatures of historical demographic events.ResultsThe mites collected were identified as the northern fowl mite Ornithonyssus sylviarum based on external morphological characterization using electron microscopy. Molecular analysis using a 756-bp long partial fragment of the cox1 gene revealed 99–100% sequence identity with NFM and phylogenetic inferences showed a bootstrap value of 99% indicating a well-supported monophyletic relationship. Molecular diversity indices showed high levels of haplotype diversity dominated by private haplotypes, but low nucleotide divergence between haplotypes. The Tajima’s D test and Fu’s Fs test showed negative value, indicating deviations from neutrality and both suggested recent population expansion of mite populations supported by a star-like topology of the isolates in the network analysis. Our genetic data are consistent with a single introduction of NFM infestations and the spread of NFM infestation in Hainan poultry farms and a private haplotype dominance, which suggest that infestations are recycled within the farms and transmission routes are limited between farms.ConclusionsTo our knowledge, this is the first time a molecular report of NFM in chicken from China including other Asian countries using DNA barcoding. The findings have potential implications with respect to understanding the transmission patterns, emergence and populations trends of parasitic infestations of poultry farms that will help for setting the parameters for integrated pest management (IPM) tactics against mite infestations.

Parasitic Mite Fauna in Asian Poultry Farming Systems

“…Of 50 countries or regions in Asia as defined by the United Nations (9), studies on poultry mites were conducted in 10 countries; including Russia (10-12), China (13,14), Japan (15)(16)(17)(18)(19), Malaysia (20), Myanmar (21), Iran (22)(23)(24)(25)(26)(27)(28), India (29,30), Pakistan (31)(32)(33)(34), Vietnam (35), and Saudi Arabia (36). The poultry mite fauna comprises four orders: mesostigmata, sarcoptiformes, acariformes, and trombidiformes.…”

“…This relationship was not possibly determined by microscopic observation. The most commonly used polymorphic gene for this purpose is mitochondrial cytochrome oxidase subunit 1 (COI) (14,15,46).…”

Divergent domains of 28S ribosomal RNA gene: DNA barcodes for molecular classification and identification of mites

“…Although rapidly developed molecular biology techniques have provided support for classification and identification of mites [11][12][13][14], there are still some problems with the classification technique of DNA barcoding: (i) a shortage of molecular data. More than 50,000 mite species have been identified in nature [15], whereas less than 100 species have molecular data available on GenBank.…”

Comparative morphological and transcriptomic analyses reveal novel chemosensory genes in the poultry red mite, Dermanyssus gallinae and knockdown by RNA interference

“…The poultry red mite (PRM), Dermanyssus gallinae (de Geer, 1778), is an obligatory hematophagous ectoparasitic mite that infests a wide range of hosts including wild birds, rodents and mammals (George et al, 2015). The PRM is considered the major pest for the poultry industry, with the annual cost in damage and control estimated at €231 million in European countries alone (Flochlay et al, 2017; Bhowmick et al, 2019). Unlike other ectoparasites in animals, PRM sucks blood mainly at night, while they hide themselves in cracks and crevices during daytime so that chickens cannot peck and eat them.…”

“…Unlike other ectoparasites in animals, PRM sucks blood mainly at night, while they hide themselves in cracks and crevices during daytime so that chickens cannot peck and eat them. Their complex behavior makes them difficult to control with conventional acaricides and other treatment practices (Bhowmick et al, 2019). Hence, an increased understanding of the peripheral olfactory system, including the identification of chemosensory receptors and the ultrastructural characteristics of chemosensory sensilla in PRM, is of great veterinary and economical interest.…”