Molecular characterization of bartonella species discovered in ectoparasites collected from domestic animals, cuzco, peru

Authors: FLORES-MENDOZA, CARMEN - Naval Medical Research Center; LOYOLA, STEEV - Naval Medical Research Center; JIANG, JU - Naval Medical Research Center; FARRIS, CHRISTINA - Naval Medical Research Center; MULLINS, KRISTIN - Naval Medical Research Center; Estep Iii, Alden; FISHER, MICHAEL - Naval Medical Research Center; RICHARDS, ALLEN - Naval Medical Research Center

Submitted to: Vector-Borne and Zoonotic Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2020
Publication Date: 2/9/2021
Citation: Flores-Mendoza, C., Loyola, S., Jiang, J., Farris, C.M., Mullins, K., Estep Iii, A.S., Fisher, M.L., Richards, A.L. 2021. Molecular characterization of bartonella species discovered in ectoparasites collected from domestic animals, cuzco, peru. Vector-Borne and Zoonotic Diseases. https://doi.org/10.1089/vbz.2020.2697.
DOI: https://doi.org/10.1089/vbz.2020.2697

Interpretive Summary: Ectoparasites on livestock can and frequently do carry diseases that can be transmitted to humans and the close contact between humans and the livestock hosts provide a ready route for disease transmission. This study was designed to survey parasites on livestock from 14 farming communities in the high Andes mountains in Peru and assess them for the presence of 2 bacterial pathogens. A secondary goal of this study was to attempt to determine the specific species of pathogens to better understand the risk to humans. We found infection of ectoparasites with Bartonella species to be relatively common but we did not find Rickettisial infections. Attempted molecular identification of the Bartonella species showed them to be most closely related to Bartonella melophagi but variant enough to be a different species. This indicates further work is warranted to define whether this is a novel species.

Technical Abstract: Rickettsiae and bartonellae are Gram-negative bacteria that can cause zoonotic and human diseases and are vectored by hematophagous arthropods. In the Americas, rickettsioses and bartonelloses have reemerged as a significant public health threats. Bartonella species have been identified as causing zoonotic infections responsible for a variety of clinical syndromes in humans and animals. The study aim was to investigate the distribution, prevalence and molecular heterogeneity of Rickettsia spp. and Bartonella spp. among ectoparasites collected from domestic animal in fourteen farming communities in the Andes Mountains of Cuzco, Peru. A total of 222 domestic animals representing 8 different species (sheep, donkeys, goats, cattle, pigs, llamas, guinea pigs, and horses) were sampled. Nine species of ectoparasites (n=1697) collected from 122 of the animals were identified resulting in 1657 chewing lice, 39 ticks, and 1 flea. DNA was individually extracted from a random sample of 600 (35.4%) considering variability of ectoparasite species, hosts and sample location elevation. All 600 samples were negative for rickettsial DNA by a genus-specific molecular assay. A subset of 172 (28.7%) samples were selected based upon variability of arthropods species, host and location for Bartonella testing. Ninety-one (52.9%) of these samples including Melophagus ovinus (90/109) and Bovicola bovis (1/7) were positive for Bartonella by a genus-specific molecular assay. Five Bartonella genes of seven DNA samples from M. ovinus were analyzed by the multilocus sequencing typing (MLST) for characterization. We identified five identical Bartonella melophagi specimens and two specimens with Bartonella species related to B. melophagi from the seven Melophagus ovinus. The Bartonella agents detected were widely distributed and frequent in multiple studied locations.