Filarial infection caused by Onchocerca boehmi (Supperer, 1953) in a horse from Italy.
Abstract: Equids can be infected by a range of skin-dwelling filarial nematodes, including four species of the genus Onchocerca. Current literature on equine onchocercosis is fragmentary and often limited to isolated case reports. The present study aimed to describe a clinical case of equine onchocercosis caused by Onchocerca boehmi (Supperer, 1953) (syn. Elaeophora boehmi) in an 8-year-old gelding Belgian show jumper from northern Italy. The horse was presented with a firm and painless mass on the proximal third of the right metacarpal region. Ultrasound examination showed a peritendinous enlargement around the palmaro-lateral area of the tendons, characterized by an elongated hypoechoic and well-defined structure, embedding a coiled hyperechoic line. The metacarpal nodule was resected and histologically examined. Fragments of a parasitic nematode were detected, isolated and examined. The morphological analysis allowed identifying the nematode as O. boehmi. In addition, total genomic DNA was extracted from individual fragments using a commercial kit for the nematode identification and a comparative sequence analysis of the nematode cytochrome oxidase subunit 1 (cox1) sequence with data available in the GenBank database revealed the closest identity (i.e. 91 %) with that of Onchocerca lupi. Thus far, O. boehmi has only been reported in Austria and Iran, and information about its life-cycle and vectors is lacking. The systematic position of this species within the genus Onchocerca, not in Elaeophora where it was originally described, is in concordance with the morphological and molecular analysis. In this article, we describe the first autochthonous case of equine onchocercosis in Italy caused by O. boehmi and discuss novel parasitological, clinical, and pathological data on these pathogens of horses.
Publication Date: 2016-10-19 PubMed ID: 27761717DOI: 10.1007/s00436-016-5277-xGoogle Scholar: Lookup
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Summary
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The research explores a clinical case of filarial infection in a horse caused by a specific nematode species, Onchocerca boehmi. Particular attention is given to the detection, analysis and comparison of the nematode, its genetic makeup, and the potential impact it may have on horses.
Case Presentation
- The research revolves around an 8-year-old gelding Belgian show jumper in northern Italy that was suffering from an unusual physical symptom – a firm, nonpainful mass on the right metacarpal region. This presented as an elongated hypoechoic and well-defined structure with an embedded coiled hyperechoic line upon ultrasound examination.
- The mass was carefully removed and subjected to histological examination for further investigation.
Identification and Analysis of Parasite
- Upon examination, fragments of a parasitic nematode were discovered. Detailed morphological analysis confirmed the samples belonged to the nematode species, Onchocerca boehmi.
- In addition to physical identification, DNA from the nematode fragments was extracted and used in genomic study. Specifically, researchers focused on the nematode’s cytochrome oxidase subunit 1 (cox1) sequence.
- The cox1 sequence allows for molecular identification as it is highly conserved among metazoans but varies enough to be used to identify species. Comparison with data available in the GenBank database brought out a 91% identity with the species Onchocerca lupi.
Significance of the Findings
- This study outlines the first case of an equine infection by Onchocerca boehmi in Italy. Before this, the only known reports of this specific nematode infections in equines had been from Austria and Iran.
- Information concerning the life-cycle and vectors of O. boehmi is currently insufficient and unclear.
- The findings in the study reaffirm the systematic placement of O. boehmi within the genus Onchocerca, as advocated by earlier morphological and molecular analyses.
- The research opens up discussions regarding parasitological, clinical, and pathological considerations concerning O. boehmi infections in horses, and necessitates the need for further investigation.
Cite This Article
APA
Lia RP, Mutafchiev Y, Veneziano V, Giannelli A, Abramo F, Santoro M, Latrofa MS, Cantacessi C, Martin C, Otranto D, Bertuglia A, Riccio B.
(2016).
Filarial infection caused by Onchocerca boehmi (Supperer, 1953) in a horse from Italy.
Parasitol Res, 116(1), 191-198.
https://doi.org/10.1007/s00436-016-5277-x Publication
Researcher Affiliations
- Dipartimento di Medicina Veterinaria, Università degli Studi di Bari Aldo Moro, Valenzano, Bari, Italy. riccardopaolo.lia@uniba.it.
- Dipartimento di Medicina Veterinaria, Università degli Studi di Bari Aldo Moro, Valenzano, Bari, Italy.
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Sofia, Bulgaria.
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università di Napoli Federico II, Napoli, Italy.
- Dipartimento di Medicina Veterinaria, Università degli Studi di Bari Aldo Moro, Valenzano, Bari, Italy.
- Dipartimento di Scienze Veterinarie, Università degli Studi di Pisa, Pisa, Italy.
- Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, Napoli, Italy.
- Dipartimento di Medicina Veterinaria, Università degli Studi di Bari Aldo Moro, Valenzano, Bari, Italy.
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK.
- UMR7245, MCAM, Museum National d'Histoire Naturelle, Paris, France.
- Dipartimento di Medicina Veterinaria, Università degli Studi di Bari Aldo Moro, Valenzano, Bari, Italy.
- Dipartimento di Scienze Veterinarie, Università degli Studi di Torino, Torino, Italy.
- Veterinary practitioner, Torino, Italy.
MeSH Terms
- Animals
- Dogs
- Electron Transport Complex IV / genetics
- Helminth Proteins / genetics
- Horse Diseases / diagnosis
- Horse Diseases / parasitology
- Horse Diseases / pathology
- Horses
- Italy
- Male
- Onchocerca / genetics
- Onchocerca / isolation & purification
- Onchocerca / physiology
- Onchocerciasis / diagnosis
- Onchocerciasis / parasitology
- Onchocerciasis / pathology
- Onchocerciasis / veterinary
- Skin / parasitology
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Citations
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