A Quantitative PCR Protocol for Detection of Oxyspirura petrowi in Northern Bobwhites (Colinus virginianus).

Whitney M Kistler,Steven T Peper,Julie A Parlos,Nicholas R Dunham,Ronald J Kendall,Baochuan Lin

doi:10.1371/journal.pone.0166309

Abstract

Oxyspirura petrowi is a parasitic nematode that infects wild birds. This parasite has a broad host range, but has recently been reported in high prevalences from native Galliformes species in the United States. In order to better understand the impact O. petrowi has on wild bird populations, we developed a quantitative PCR protocol to detect infections in wild northern bobwhites (Colinus virginianus). We used paired fecal and cloacal swab samples from wild caught and experimentally infected northern bobwhites and matching fecal float data from experimentally infected birds to validate our assay. Overall we detected more positive birds from fecal samples than the paired cloacal swabs and there was strong agreement between the qPCR results from fecal samples and from fecal flotation (84%; κ = 0.69 [0.53–0.84 95% CI]). We also detected O. petrowi DNA in ten replicates of samples spiked with one O. petrowi egg. This qPCR assay is an effective assay to detect O. petrowi infections in wild birds. Our results suggest that fecal samples are the most appropriate sample for detecting infections; although, cloacal swabs can be useful for determining if O. petrowi is circulating in a population.

Highlights

Parasites of the genus Oxyspirura (Spirurida: Thelaziidae) are heteroxenous nematodes that primarily use avian species as definitive hosts [1]
O. petrowi has been detected in high prevalences in northern bobwhites (Colinus virginianus) in western Texas [3], and lesser prairie chickens (Tympanuchus pallidicinctus) in southwestern Kansas [2,7]
We tested the O. petrowi quantitative PCR (qPCR) assay with a hydrolysis probe as a single qPCR and as a duplex qPCR with the northern bobwhite NADH dehydrogenase 2 mitochondrial gene (ND2)

Summary

Introduction

Parasites of the genus Oxyspirura (Spirurida: Thelaziidae) are heteroxenous nematodes that primarily use avian species as definitive hosts [1]. Oxyspirura petrowi has recently received increased attention because of high prevalences detected in declining native Galliformes populations in North America [2,3]. O. petrowi has been detected in high prevalences in northern bobwhites (Colinus virginianus) in western Texas [3], and lesser prairie chickens (Tympanuchus pallidicinctus) in southwestern Kansas [2,7]. Over the last century northern bobwhite and lesser prairie chicken populations have been going experiencing declines [8,9]. The cause of these decline has been largely attributed to habitat

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