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Aulonocephalus pennula is a nematode living in the caeca of the wild Northern bobwhite quail (Colinus virginianus) present throughout the Rolling Plains Ecoregion of Texas. The cytochrome oxidase 1 (COX 1) gene of the mitochondrial genome was used to screen A. pennula in wild quail. Through BLAST analysis, similarity of A. pennula to other nematode parasites was compared at the nucleotide level. Phylogenetic analysis of A. pennula COX1 indicated relationships to Subuluridae, Ascarididae, and Anisakidae. This study on molecular characterization of A. pennula provides new insight for the diagnosis of caecal worm infections of quail in the Rolling plains Ecoregion of Texas.

The potential of parasites to affect host abundance has been a topic of heated contention within the scientific community for some time, with many maintaining that issues such as habitat loss are more important in regulating wildlife populations than diseases. This is in part due to the difficulty in detecting and quantifying the consequences of disease, such as parasitic infection, within wild systems. An example of this is found in the Northern bobwhite quail ( Colinus virginanus ), an iconic game bird that is one of the most extensively studied vertebrates on the planet. Yet, despite countless volumes dedicated to the study and management of this bird, bobwhite continue to disappear from fields, forest margins, and grasslands across the United States in what some have referred to as “our greatest wildlife tragedy”. Here, we will discuss the history of disease and wildlife conservation, some of the challenges wildlife disease studies face in the ever-changing world, and how a “weight of evidence” approach has been invaluable to evaluating the impact of parasites on bobwhite in the Rolling Plains of Texas. Through this, we highlight the potential of using “weight of the evidence” to better understand the complex effects of diseases on wildlife and urge a greater consideration of the importance of disease in wildlife conservation.

BackgroundOxyspirura petrowi (Spirurida: Thelaziidae), a heteroxenous nematode of birds across the USA, may play a role in the decline of the northern bobwhite (Colinus virginianus) in the Rolling Plains Ecoregion of West Texas. Previous molecular studies suggest that crickets, grasshoppers and cockroaches serve as potential intermediate hosts of O. petrowi, although a complete study on the life-cycle of this nematode has not been conducted thus far. Consequently, this study aims to improve our understanding of the O. petrowi life-cycle by experimentally infecting house crickets (Acheta domesticus) with O. petrowi eggs, feeding infected crickets to bobwhite and assessing the life-cycle of this nematode in both the definitive and intermediate hosts.MethodsOxyspirura petrowi eggs were collected from gravid worms recovered from wild bobwhite and fed to house crickets. The development of O. petrowi within crickets was monitored by dissection of crickets at specified intervals. When infective larvae were found inside crickets, parasite-free pen-raised bobwhite were fed four infected crickets each. The maturation of O. petrowi in bobwhite was monitored through fecal floats and bobwhite necropsies at specified intervals.ResultsIn this study, we were able to infect both crickets (n = 45) and bobwhite (n = 25) with O. petrowi at a rate of 96%. We successfully replicated and monitored the complete O. petrowi life-cycle in vivo, recovering embryonated O. petrowi eggs from the feces of bobwhite 51 days after consumption of infected crickets. All life-cycle stages of O. petrowi were confirmed in both the house cricket and the bobwhite using morphological and molecular techniques.ConclusionsThis study provides a better understanding of the infection mechanism and life-cycle of O. petrowi by tracking the developmental progress within both the intermediate and definitive host. To our knowledge, this study is the first to fully monitor the complete life-cycle of O. petrowi and may allow for better estimates into the potential for future epizootics of O. petrowi in bobwhite. Finally, this study provides a model for experimental infection that may be used in research examining the effects of O. petrowi infection in bobwhite.

Oxyspirura petrowi is a heteroxenous nematode found in northern bobwhite (Colinus virginianus) of the Rolling Plains ecoregion of Texas. Despite its impact on this popular gamebird, genetic level studies on O. petrowi remain relatively unexplored. To accomplish this, we chose the previously studied nuclear rDNA 18S region as well as the mitochondrial COX1 gene region of O. petrowi to investigate phylogenetic relations between O. petrowi and other nematode species. In this study, we generate primers using multiple alignment and universal nematode primers to obtain a near-complete 18S and partial COX1 sequence of O. petrowi, respectively. Phylogenetic trees for O. petrowi's 18S and COX1 gene regions were constructed using the Maximum Likelihood and Maximum Parsimony method. A comparative analysis was done based on the nuclear and mitochondrial region similarities between O. petrowi and other nematode species that infect both humans and animals. Results revealed a close relation to the zoonotic eyeworm Thelazia callipaeda as well as a close relation with filarial super family (Filarioidea) such as the human eyeworm Loa loa and Dirofilaria repens eyeworm of dog and carnivores.