Sebastián Muñoz Leal

University of Concepción · Departamento de Ciencia Animal

Background Bacteria of the genus Borrelia are agents of disease in both domestic animals and humans and pose a significant public health risk. Borrelia species have complex transmission cycles, often using rodents as vertebrate reservoir hosts. These bacteria are classified into three well-defined monophyletic groups: Borrelia burgdorferi sensu lat...

Introduction This study investigates the genetic variability of Hydatigera taeniaeformis in black rats (Rattus rattus), a common tapeworm that infects cats and rodents worldwide. Despite its widespread presence and zoonotic potential, little is known about the genetic diversity of this parasite in the Americas. Methods We conducted DNA barcoding a...

Lyme borreliosis or Lyme disease is the most frequently reported tick-borne disease in the Northern Hemisphere. In countries of the Southern Hemisphere, such as Brazil, since the early 1990s, some researchers have argued for the existence of an autochthonous Lyme-like borreliosis, known locally as the Baggio–Yoshinari syndrome (BYS), an alleged “Br...

Soft ticks (Argasidae) of the subgenus Pavlovskyella Pospelova-Shtrom are worldwide distributed parasites of medical importance. However, the systematics of the subgenus are currently under debate because genetic data shows that the group is paraphyletic. Meanwhile, species of Pavlovskyella continue to be discovered. In this study a novel species o...

The genus Ornithodoros is notably diverse within the family Argasidae, comprising approximately 134 species distributed among 4 subgenera, 1 of which is the subgenus Pavlovskyella. In an earlier study, we identified distinct soft ticks as Ornithodoros (Pavlovskyella) sp., which were collected from animal shelters in Khyber Pakhtunkhwa, Pakistan. Pr...

Syngamid worms (Nematoda: Syngamidae) parasitizing birds of prey are considered cosmopolitan, but the efforts to understand their biology and systematics are restricted to the Holarctic region. However, in the Neotropical region there is only one recent record with no data about its molecular characterization or its significance to the health of it...

Accumulation of DNA sequence data and its use in systematics of the family Argasidae reveals new incon-gruencies between genera and subgenera, since several groups defined by classical taxonomy appear to be paraphyletic, which is the case of the subgenus Pavlovskyella. In order to identify morphological characters unique to one of the monophyletic...

There is limited knowledge about tick diversity in the Amazon region. Here, we survey small terrestrial mammals for tick infestation at the Rio Pardo settlement, Amazonas State, Brazil. Sampling included rainy and dry seasons and four ecotones (primary forest, forest in regeneration, field crops and households). Each animal was inspected for ticks,...

Background Ticks are obligate hematophagous ectoparasites involved in transmitting viruses of public health importance. The objective of this work was to identify the Jingmen tick virus in hard ticks from the Colombian Caribbean, an arbovirus of importance for public health. Methods Ticks were collected in rural areas of Córdoba and Cesar, Colombi...

Relative to the numerous studies focused on mammalian schistosomes, fewer include avian schistosomatids particularly in the southern hemisphere. This is changing and current research emerging from the Neotropics shows a remarkable diversity of endemic taxa. To contribute to this effort, nine ducks (Spatula cyanoptera, S. versicolor, Netta peposaca)...

This study aimed to detect, isolate and to characterize by molecular methods a relapsing fever group (RFG) Borrelia in white-eared opossums (Didelphis albiventris) from Brazil. During 2015–2018, when opossums (Didelphis spp.) were captured in six municipalities of the state of São Paulo, Brazil, molecular analyses revealed the presence of a novel R...

Las garrapatas blandas representan un grupo desatendido de ectoparásitos asociadas con una amplia gama de vertebrados. En México se han reportado 24 especies, la mayoría parasitando murciélagos. Varias especies son vectores competentes de una amplia gama de microorganismos patógenos. Por esta razón, el objetivo del presente trabajo fue identificar...

The tick fauna of El Salvador is currently represented by 10 species of hard ticks (family Ixodidae) and two species of soft ticks (family Argasidae). This study aimed to report new and additional records of ticks and rickettsiae in El Salvador. During 2019–2021, a total of 216 specimens of ticks were collected from eight host species (domestic and...

Tick-borne infectious agents (TBIAs) include several bacteria and protozoa that can infect vertebrates, including humans. Some of these agents can cause important diseases from both a public health perspective, such as Lyme disease, and from an animal health and production viewpoint, such as Texas fever. In Chile, several studies have assessed the...

Metazoan parasites of Chilean owls are scarcely known. We provide data about metazoan parasites of the Rufous-legged Owl (Strix rufipes), a forest-dependent species. Between 2012 and 2018, we examined for parasites eight Rufous-legged Owl carcasses from Ñuble and Biobío regions, south-central Chile. Seven out of eight owls hosted at least one paras...

Anatids (ducks, geese) host a great lice diversity. However, there is scarce knowledge about the lice diversity in Chilean ducks, geese, and swans. Here, we describe the lice species parasitizing seven species of duck and three species of geese inhabiting Chile. Among all sampled anatid species, we found eight lice species. The Yellow billed Pintai...

Ticks are hematophagous arthropods that naturally maintain and spread infectious microorganisms (MOs), such as viruses, bacteria, protozoans, and helminths. In fact, ticks are the main vectors of MO in wild vertebrates. In the Neotropical Zoogeographical Region (NZR), the study of tick-borne MO in wild animals has gained attention because pathogens...

Background The study of parasites provides insight into intricate ecological relationships in ecosystem dynamics, food web structures, and evolution on multiple scales. Hepatozoon (Eucoccidiorida: Hepatozoidae) is a genus of protozoan hemoparasites with heteroxenous life cycles that switch infections between vertebrates and blood-feeding invertebra...

The chewing louse genus Eutrichophilus Mjöberg has 19 species only associated with porcupines (Rodentia: Erethizontidae). Of these species, E. cercolabes, E. cordiceps, E. emersoni, E. minor, E. moojeni, and E. paraguayensis have been recorded in Brazil. In the present study, we report E. cordiceps for the first time in the São Paulo State (Bauru M...

Citation: Hidalgo-Hermoso, E.; Verasay Caviedes, S.; Pizarro-Lucero, J.; Cabello, J.; Vicencio, R.; Celis, S.; Ortiz, C.; Kemec, I.; Abuhadba-Mediano, N.; Asencio, R.; et al. High Exposure to Livestock Pathogens in Southern Pudu (Pudu puda) from Chile. Animals 2024, 14, 526. https://

Tick-borne relapsing fever spirochetes of genus Borrelia thrive in enzootic cycles involving Ornithodoros spp. (Argasidae) mainly, and rodents. The isolation of these spirochetes usually involves a murine model in which ticks are fed and the spirochetes detected in blood several days later. Such an experiment also demonstrates that a given species...

Introduction Herpesvirus infections have been highlighted as emerging diseases affecting wildlife health and the conservation of several taxa. Malignant catarrhal fever (MCF) and infectious keratoconjunctivitis (IKC) are two viruses that infect wild ruminants. Nevertheless, epidemiological data on herpesviruses in South American wild ruminants are...

Background The genus Borrelia comprises pathogenic species of bacteria that pose a significant risk to public health. Borrelia spp. are emerging or reemerging infectious agents worldwide with complex transmission cycles, and many species use rodents as vertebrate reservoir hosts. Spirochetes morphologically compatible with Borrelia have been recurr...

Tick-borne relapsing fever spirochetes of genus Borrelia thrive in enzootic cycles involving Ornithodoros spp. (Argasidae) mainly, and rodents. The isolation of these spirochetes usually involves a murine model in which ticks are feed and the spirochetes detected in blood several days later. Such an experiment also demonstrates that a given species...

Babesia spp. are tick-borne protozoans that involve birds and mammals in their transmission cycles and cause babesiosis, a severe hemolytic malaria-like disease. Opossums of the genus Didelphis are recognized hosts of tick-borne pathogens. Therefore, exploring tick-borne agents in Didelphis species is important to understand the circulation of path...

Soft ticks (Argasidae) of the Pavlovskyella Pospelova-Shtrom subgenus are important vectors of relapsing fever spirochetes, which are agents of disease globally. South American representatives of the Pavlovskyella subgenus include 3 species: Ornithodoros (Pavlovskyella) brasiliensis Aragão, Ornithodoros (Pavlovskyella) furcosus Neumann, and Ornitho...

Mesocestoides is a controversial tapeworm with significant lack of data related to systematics and life cycles. This helminth has an indirect life cycle with vertebrates, mostly carnivorous mammals, as definitive hosts. Theoretically, a coprophagous arthropod would be the first intermediate host, and herptiles, mammals, and birds, which prey on the...

In Chile, studies of parasites from the family Sarcocystidae (Apicomplexa) have mostly been related to domestic animals. We aimed to assess the presence of Sarcocystidae taxa in cricetid rodents from Central and Southern Chile. We studied 207 rodents, encompassing six species, from 13 localities. We isolated DNA from tissue samples, amplified the S...

The black-faced ibis, Theristicus melanopis, is considered a useful bird species for agricultural activity because it preys upon various invertebrate and vertebrate pests. Although it is a common species in Chile, limited information is available regarding its parasites. The main objective of this study was to recover the diversity of ectoparasites...

Spirochetes in the genus Borrelia (Spirochaetes) are the etiological agents of two zoonotic diseases that have rodents as reservoirs: the Lyme disease, transmitted by ixodid ticks (Ixodidae), and tick-borne relapsing fever, which is transmitted mostly by argasid ticks (Argasidae). The information on the epidemiology of pathogens that affect animals...

Human land use causes habitat loss and fragmentation, influencing host-parasite associations through changes in infestation rates, host mortality and possibly local extinction. Bat-ectoparasite interactions are an important host-parasite model possibly affected by such changes, as this system acts as both reservoirs and vectors of several pathogens...

Previous studies monitoring free-ranging capybaras with GPS collars showed no evidence of capybara dispersion or the formation of new groups. These phenomena may have gone unnoticed due to the low number of collared capybaras in previous studies. Aiming to fill this lacuna, this study monitored the group dynamics of capybaras in a human-modified la...

ticks (Acari: Argasidae) in South America have been found to be the most frequent carriers of borreliae of the relapsing fever group (RFG); however, there are several information gaps specially on the taxonomy and distribution of some tick species. Here, we used light microscopy, scanning electron microscopy, and PCR amplification of a fragment of...

Tick-borne relapsing fever group (RFG) borreliosis remains neglected as a human disease and little is known on its maintenance in ticks and vertebrates, especially in South America. Therefore, this study investigated borrelial infection in Ornithodoros ticks collected in rodent-inhabited rock formations in the Brazilian semiarid region, within the...

Background Deer species play an important role in the enzootic cycles of several Anaplasma species. While in the Northern Hemisphere ticks of genus Ixodes are well recognized vectors of these intracellular bacteria, less is known regarding the biological cycles of Anaplasma spp. in South America. Methods Using PCR protocols and Sanger sequencing,...

Background: The genus Borrelia is composed of two well-defined monophyletic groups, the Borrelia burgdorferi sensu lato complex (Bb) and the relapsing fever (RF) group borreliae. Recently, a third group, associated with reptiles and echidnas, has been described. In general, RF group borreliae use rodents as reservoir hosts; although neotropical bat...

Chiggers are larval ectoparasites of the Trombiculidae that can transmit pathogens to their hosts. In this study, chiggers collected from birds in Brazil were morphologically identified as Blankaartia sinnamaryi, Eutrombicula batatas, Eutrombicula daemoni, Eutrombicula goeldii, Eutrombicula tinami, and Parasecia gilbertoi. For these specimens, a be...

A large number of tick species are proven vectors for the transmission of bacteria, protozoa, and viruses. Soft ticks (Acari: Argasidae) in South America have been found to be the most frequent carriers of borreliae of the relapsing fever group (RFG); however, there are several information gaps specially on the taxonomy and distribution of some tic...

The mitochondrial genome (mitogenome) has proven to be important for the taxonomy, systematics, and population genetics of ticks. However, current methods to generate mitogenomes can be cost-prohibitive at scale. To address this issue, we developed a cost-effective approach to amplify and sequence the whole mitogenome of individual tick specimens....

The black-faced ibis, Theristicus melanopis, is considered a useful bird species for agricultural activity because it preys upon various invertebrate and vertebrate pests. Although it is a common species in Chile, limited information is available regarding its parasites. The main objective of this study was to recover the diversity of ectoparasites...

Three studies on the biology of Ornithodoros puertoricensis are available in the literature, using different hosts and incubation temperatures. In a previous study, we identified O. puertoricensis in the Colombian Caribbean. The aim of the present work was to analyze life cycle data along one generation from these specimens under laboratory conditi...

Cervids are important hosts for ticks and although they are refractory to some tick-borne agents such as Borrelia they do act as reservoirs for others such as Babesia. Babesia and Borrelia are commonly transmitted by Ixodes spp. associated with deer, and most of the knowledge on their biological cycles comes from northern latitudes of the globe. In...

Cervids are important hosts for ticks and although they are refractory to some tick-borne agents such as Borrelia they do act as reservoirs for others such as Babesia. Babesia and Borrelia are commonly transmitted by Ixodes spp. associated with deer, and most of the knowledge on their biological cycles comes from northern latitudes of the globe. In...

Borrelia theileri is a relapsing fever group Borrelia that is transmitted to cattle by ticks of the genus Rhipicephalus. In this study, we describe the first molecular detection of B. theileri subclinical infection in a cow in Brazil. During the examination of stained blood smears of 10 cows from a farm with a recent history of fatal Trypanosoma vi...

The bacterial genus Borrelia comprises vector-borne spirochetes that have been classified into three major groups: the relapsing fever group (RFG), the Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner sensu lato group (Bbsl), and the reptile-monotreme group (RMG). All three groups have been associated mainly with ticks and wild ani...

Equine coital rash (ECE) is a highly contagious benign infection that induces lesions on external genitals, and it is caused by the equine herpesvirus type 3 (EHV‐3). Although the disease is globally distributed, its presence in Chile has not been documented from a genetic point of view. Here, we performed polymerase chain reaction screenings for E...

Background The genus Borrelia is composed of two well-defined monophyletic groups that contain pathogens in humans: the Borrelia burgdorferi sensu lato complex (Bb), and relapsing fever (RF) group borreliae. Recently, a third group, associated with reptiles and echidnas has been described. In general, RF group borreliae use rodents as reservoir hos...

Ticks are hematophagous ectoparasites of terrestrial and semi-aquatic vertebrates that may transmit microorganisms to their hosts. Spirochetes of the genus Borrelia are common in ticks and an incipient group has been identified in association with reptiles and their tick parasites. To overcome the knowledge deficit, this study aimed to morphologica...

Records of accidental parasitism by ticks in humans from Brazil are scarce, with most being reported by researchers who are parasitized during their research and by professionals who work with animals. In order to compile these records, an extensive literature review was carried out. Our revision includes studies published between 1909 and 2022, in...

Relapsing fever group Borrelia (RFGB) are motile spirochetes transmitted to mammalian or avian hosts through the bite of hematophagous arthropods, such as soft ticks (Argasidae), hard ticks (Ixodidae) and the human clothing lice. RFGB can infect pets such as dogs and cats, as well as birds, cattle and humans. Borrelia recurrentis, B. anserina and B...

Background Tick-borne relapsing fever (TBRF) is a globally prevalent, yet under-studied vector-borne disease transmitted by soft and hard bodied ticks. While soft TBRF (sTBRF) spirochetes have been described for over a century, our understanding of the molecular mechanisms facilitating vector and host adaptation is poorly understood. This is due to...

Ornithodoros mimon is an argasid tick primarily associated with bats that also infest other animals including birds, opossums and humans. In this paper, we report the finding of an argasid species resembling O. mimon, which similarly may be found in human dwellings and parasitize humans in Brazil. We also provide molecular evidence that this argasi...

The present study analyzes the diversity of bacteria of the genus Rickettsia in ticks collected from wild mammals and vegetation at the Chamela Biological Station (EBCh), Jalisco, Mexico, a core area in the Chamela-Cuixmala Biosphere Reserve, which is characterized by the presence of tropical dry forest, one of the most threatened ecosystems in the...

Background: Soft ticks (Ixodida: Argasidae) are medically important ectoparasites that mainly feed on birds and mammals that play a key role in the geographic distribution and dispersion of these ticks. Despite their importance, studies on soft ticks are scarce in many regions of the world, including Pakistan. Methods: In this study, 2,330 soft tic...

In Brazil, 19 species of the genus Ornithodoros (Acari: Argasidae) have been reported. The medical and veterinary importance of Ornithodoros ticks has increased substantially in recent decades, with the discovery of various relapsing fever Borrelia infecting Ornithodoros ticks. Herein, argasid ticks were collected during 2019–2020 from caves, aband...

Background Small mammals (rodents and marsupials) have been poorly explored for the occurrence of apicomplexan (genus Hepatozoon and genera of the order Piroplasmorida) and Anaplasmataceae agents in Brazil. Thus, this study investigated the occurrence of Hepatozoon spp., Piroplasmorida, and Anaplasmataceae agents in small mammals in seven forest fr...

Small mammals play an essential role as disseminators of pathogens because they reach high population densities and have ubiquitous distributions. In the Northern Hemisphere rodents are well recognized as reservoirs for tick-borne bacteria of the Anaplasmataceae family and also apicomplexan protozoans. In contrast, South American rodents hosting th...

Borrelia burgdorferi sensu lato (Bbsl) spirochetes thrive in sylvatic transmission cycles infecting vertebrates and their ticks. Rodents and ticks of the genus Ixodes are important hosts of these spirochetes globally. Although evidence suggests that Borrelia burgdorferi sensu stricto does not exist in South America, genospecies of the group (Bbsl)...

Ticks are significant parasites of dogs in the tropics, where tick-borne pathogens are highly prevalent, especially in areas where tick control measures are frequently neglected. This study investigated the seroprevalence and hematological abnormalities associated with Ehrlichia canis in dogs referred to a veterinary teaching hospital in Central-we...

Human ehrlichiosis are scantily documented in Uruguay. The aim of this study was to investigate the presence of Ehrlichia spp. in Haemaphysalis juxtakochi and in a gray brocket deer (Mazama gouazoubira) from Uruguay. The presence of Ehrlichia DNA was investigated in free-living H. juxtakochi in five localities of southeast and northeast Uruguay, as...

In South America, apicomplexan parasites of the genus Hepatozoon have been sporadically detected in mammals. Previous studies in wild canids from Brazil and Argentina demonstrated infections by species genetically related to Hepatozoon americanum. The aim of the present work was to detect the presence of Hepatozoon in road-killed foxes encountered...

Introducción: Las rickettsiosis son enfermedades emergentes transmitidas por vectores artrópodos cuyos agentes etiológicos corresponden a bacterias patógenas del género Rickettsia y Orientia . Bacterias de este género han sido descritas en el norte y sur de Chile. Objetivo: Determinar presencia de Rickettsia spp. en garrapatas colectadas a partir...