Evidence map›Paper›PMID 42862496›Full record

ArticleActa parasitologica2026

Molecular Detection of Anaplasma marginale in the Central Region of Venezuela: A PCR-based Assessment of the msp2 and msp5 Genes.

Mariana Carolina Eleizalde, Marta Mendoza, Armando Reyna-Bello, Lucinda Tavares-Marques, Miguel Martínez-Fresneda, Ely Gómez-Piñeres, José Rubén Ramírez-Iglesias

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Article in Acta parasitologica, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Mariana Carolina EleizaldeInstituto de Estudios Científicos y Tecnológicos, Centro de Estudios Biomédicos y Veterinarios, Universidad Nacional Experimental Simón Rodríguez, Caracas, Venezuela. eleizaldemariana@gmail.com.
Marta MendozaInstituto de Estudios Científicos y Tecnológicos, Centro de Estudios Biomédicos y Veterinarios, Universidad Nacional Experimental Simón Rodríguez, Caracas, Venezuela.
Armando Reyna-BelloGrupo de Investigación en Sanidad Animal y Humana (GISAH), Carrera de Ingeniería en Biotecnología, Departamento de Ciencias de la Vida y la Agricultura, Universidad de las Fuerzas Armadas ESPE, Santo Domingo, Ecuador.
Lucinda Tavares-MarquesInstituto de Estudios Científicos y Tecnológicos, Centro de Estudios Biomédicos y Veterinarios, Universidad Nacional Experimental Simón Rodríguez, Caracas, Venezuela.
Miguel Martínez-FresnedaFacultad de Veterinaria, Universidad Alfonso X el Sabio (UAX), Avenida de la Universidad 1, 28691 Villanueva de la Cañada, Madrid, España.
Ely Gómez-PiñeresDepartamento de Ingeniería en Producción Animal, Escuela de Ciencias del Agro y del Ambiente, Núcleo de Monagas, Universidad de Oriente, Maturín, Venezuela.
José Rubén Ramírez-IglesiasGroup for Neglected-Emerging Diseases, Health Sciences Faculty, Eco-Epidemiology and Biodiversity, Universidad Internacional SEK, Quito, Ecuador.

Funding

Estrategias de adaptación y mitigación en comunidades de montaña ubicada en la Cordillera de la Costa frente al cambio climático, (grant N° 2011000981) and Redes Socialistas de Innovación Productiva (RSIP) de ganadería doble propósito en la región central del país 2011000981UISEK DII-P011617_2
6 · The paper itself

Abstract

backgroundBovine anaplasmosis reduces livestock productivity in cattle, making timely and accurate diagnosis essential for epidemiological surveillance. PURPOSE: To explore alternative primers for pathogen detection beyond the reference 19A/19B set targeting the single-copy msp5 gene and to update epidemiologic data we evaluated analytical and field performance of primers designed for the multicopy msp2 gene, using conserved terminal regions (msp2A/B). We also described the prevalence of A. marginale in specific sampled herds from several regions of Venezuela.

methodsPCR conditions were standardized, and the analytical sensitivity of msp2A/B and 19A/B was evaluated. Field evaluations involved 208 cattle from small farms in four distinct geographical regions of Venezuela (Aragua, Cojedes, Guárico, and Miranda), divided into two groups with different clinical characteristics.

resultsBoth primer sets detected the pathogen at concentrations as low as 0.01 ng. In a herd of 24 cattle experiencing an anaplasmosis outbreak, positivity rates were 12.5% and 66.67% using primers msp2A/B and 19A/B, respectively. One of the positive field-sample amplicons was cloned and sequenced to confirm bacterial identity, yielding a 97% BLAST identity with complete coverage to the reference strain Florida. Additionally, 10 and 5 nucleotide substitutions were detected at the 5' and 3' ends, respectively, compared to the reference isolate. This suggests terminal heterogeneity in the gene that may contribute to the reduced diagnostic performance of msp2A/B. Additionally, 184 clinically healthy cattle analyzed solely with 19A/B revealed a subclinical prevalence of 41.85%.

conclusionIn a country with limited recent molecular reports, these findings underscore the epidemiological relevance of persistent infections. This study also constitutes the first report of an msp2 sequence from a Venezuelan A. marginale isolate, providing preliminary insights of the genetic diversity of A. marginale and support using msp5-based PCR for routine field detection and surveillance in Venezuela.

Indexed as

Anaplasma marginaleAnaplasmosisAntigens, BacterialBacterial Outer Membrane ProteinsCattle DiseasesPolymerase Chain ReactionAnimalsCattleDNA PrimersPrevalenceSensitivity and SpecificityVenezuelaAntigens, BacterialBacterial Outer Membrane ProteinsDNA Primersmajor surface protein 5, Anaplasmamsp2 protein, Anaplasma phagocytophilumA. marginaleAnaplasmosismsp2msp5PCRVenezuela

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.