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Molecular Characterization of Bartonella Species Discovered in Ectoparasites Collected from Domestic Animals, Cuzco,
Carmen Flores-Mendoza1, Steev Loyola1, Ju Jiang2
1U.S. Naval Medical Research Unit No. 6, Lima, Peru.
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 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 aim of this study was to investigate the distribution, prevalence, and molecular heterogeneity of Rickettsia spp. and Bartonella spp. among ectoparasites collected from domestic animals in 14 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 = 1,697) collected from 122 animals were identified resulting in 1,657 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 173 (28.8%) samples were selected based on variability of arthropods species, host, and location for Bartonella testing. Ninety-one (52.6%) of these samples including Melophagus ovinus (90/110) 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 sequence typing for characterization. We identified five identical Bartonella melophagi specimens and two specimens with Bartonella species related to B. melophagi from the seven M. ovinus. The Bartonella agents detected were widely distributed and frequent in multiple studied locations.
Insights
Bartonella bacteria were frequently detected in ectoparasites from domestic animals in Peru, with Bartonella melophagi identified in sheep keds. Rickettsia bacteria were not found in this study.
Area of Science:
- Zoonotic disease research
- Veterinary entomology
- Molecular microbiology
Background:
- Rickettsiae and bartonellae are Gram-negative bacteria causing zoonotic diseases, vectored by arthropods.
- Rickettsioses and bartonelloses are reemerging public health threats in the Americas.
- Bartonella species cause diverse clinical syndromes in humans and animals.
Purpose of the Study:
- To investigate the distribution, prevalence, and molecular characteristics of Rickettsia and Bartonella species.
- Focus on ectoparasites from domestic animals in the Andes Mountains of Cuzco, Peru.
Main Methods:
- Sampling of 222 domestic animals across 8 species and 9 ectoparasite species (lice, ticks, flea).
- DNA extraction from 600 ectoparasite samples for genus-specific molecular assays.
- Multilocus sequence typing (MLST) for molecular characterization of positive Bartonella samples.
Main Results:
- All 600 samples tested negative for Rickettsia DNA.
- Bartonella DNA was detected in 52.6% of 173 tested ectoparasite samples.
- Bartonella was prevalent in Melophagus ovinus (sheep keds) and Bovicola bovis (cattle louse).
- MLST identified Bartonella melophagi in M. ovinus, with other related Bartonella species also detected.
Conclusions:
- Bartonella agents are widely distributed and frequent in ectoparasites of domestic animals in the study area.
- Melophagus ovinus is a significant host for Bartonella, including Bartonella melophagi.
- Rickettsia species were not detected in the sampled ectoparasites.
