Development and validation of 2 probe-hybridization quantitative PCR assays for rapid detection of a pathogenic Coxiella species in captive psittacines. (May 2020)

• Record Type: Journal Article
• Authors: Flanders, Alison J.; Speer, Brian; Reavill, Drury R.; Roberts, John F.; Childress, April L.; Atlas, Alvin; Wellehan, James F. X.
• Is Part Of: Journal of veterinary diagnostic investigation. Volume 32:Number 3(2020:May)
• Page Start: 423
• Page End: 428
• Publication Date: 2020-05
• Subjects: birds -- Coxiella -- parrots -- quantitative PCR; Veterinary medicine -- Diagnosis -- Periodicals; 636.0896075
• DOI: 10.1177/1040638720912221
• Languages: English
• ISSNs: 1040-6387

Abstract

Avian coxiellosis is an emerging cause of morbidity and mortality among captive psittacines, and the utility of a rapid detection test using easily obtained samples is paramount in a clinical setting. New sequences were obtained from 3 genes: groEL, dnaK, and rpoB . We developed probe-hybridization quantitative PCR (qPCR) assays using groEL and dnaK genes. Samples, including splenic aspirates, liver aspirates, whole blood, and choanal, conjunctival, and cloacal swabs, were collected from 4 psittacine species including 3 blue-and-gold macaws ( Ara ararauna ), 2 scarlet-chested parrots ( Neophema splendida ), 1 Timneh African grey parrot ( Psittacus timneh ), and 1 yellow-naped Amazon parrot ( Amazona auropalliata ). Retrospective review of postmortem findings from 3 of these psittacines included splenomegaly, hepatitis, and/or transmission electron microscopy confirmation consistent with previous reports of avian coxiellosis. There was 100% agreement between these assays and consensus PCR with sequencing. A Wilcoxon rank-sum test found a strong correlation between groEL and dnaK cycle threshold values ( p < 0.001), validating these assays for detection of this avian Coxiella sp.