Recombinant BPRAG1 Protein-Based Serodiagnostic Assays for Detection of Baylisascaris Larva Migrans in Birds and Non-Human Primates

Jannatul Shabnam, Purdue University

Abstract

Baylisascaris procyonis is an intestinal roundworm commonly found in raccoons and can accidentally infect more than 160 animal species. In these accidental hosts,Baylisascaris larval stages migrate through body tissues resulting in a zoonotic disease known as larva migrans that can result in permanent neurological damage or death. Currently, there are no suitable antemortem serological tests for the diagnosis of Baylisascaris larva migrans in birds and non-human primates. The objective of this study was to establish reliable serodiagnostic tests to detect Baylisascaris larva migrans in birds and non-human primates. The enzyme-linked immunosorbent assay (ELISA) and western blot (WB) based serodiagnostic assays were standardized using the recombinant B. procyonis RAG1 antigen (rBpRAG1) currently being used in the serodiagnosis of Baylisascaris infection in humans. To overcome the challenge of using different species-specific secondary antibodies, protein A/G was utilized in place of secondary antibody for non-human primates’ ELISA and WB assay and an anti-bird secondary antibody was utilized to optimize the serodiagnostic assays for birds. Cockatiels (group I, n=5) exposed to B. procyonis larval antigens through hyperimmunization with larval ES proteins exhibited 100% seroconversion, while cockatiels (group IIa, n=9, 1400 eggs and group IIb, n=9, 2200 eggs) that were orally infected with two different doses ofB. procyonis eggs demonstrated variable levels of antibody response and seroconversion rates (56%-67%) on the rBpRAG1 ELISA. Sera of 138 non-human primates submitted from different zoological parks across the United States were tested on rBpRAG1 ELISA and WB. Approximately 24% of the samples were non-reactive in both the ELISA and western blot assays and were considered as true negatives. Among those that were considered suspect reactors or positives on ELISA, the results were not congruent on WB. Approximately 21% of the samples reacted with both rBpRAG1 and co-purified bacterial proteins, and 14% of the samples only reacted with the co-purified proteins. Since ELISA alone can incur false positives due to reactivity with co-purified proteins, it is recommended to use rBpRAG1 ELISA in conjunction with WB for diagnosis of Baylisascarislarva migrans in non-human primates.

Degree

M.Sc.

Advisors

Dangoudoubiyam, Purdue University.

Subject Area

Pathology|Morphology|Animal sciences|Ecology|Genetics|Neurosciences|Organic chemistry|Parasitology|Plant Pathology|Systematic biology|Zoology

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