Potential zoonotic role of the tick Amblyomma cf. oblongoguttatum (Ixodida: Ixodidae) in the bacterial transmission of Ehrlichia chaffeensis (Rickettsiales: Anaplasmataceae) in a deciduous tropical forest in Mexico.

Ehrlichia chaffeensis is a bacterium belonging to the Anaplasmataceae family. In Mexico, only 2 species have been recorded in association with tick species and humans. The objective of the present study was to detect the presence of bacteria of the genus Ehrlichia in ticks collected from the Chamela-Cuixmala Biosphere Reserve, Jalisco, Mexico. The collected ticks were identified and analyzed individually by polymerase chain reaction to amplify a fragment of the Anaplasmataceae 16S rRNA gene and the Ehrlichia-specific dsb gene. A total of 204 ticks, corresponding to 5 species of Ixodidae and 1 of Argasidae, were collected from 147 mammals of 6 species and 4 orders; 57 ticks collected from vegetation were also included. Among the total ticks collected, 1.47% (3/204) was positive for Ehrlichia sp. DNA was obtained using the primers EHR 16SD and EHR 16SR for 16S rRNA and DSB-330 and DSB-728 for dsb. The positive samples corresponded to a larva (Amblyomma sp.) associated with Didelphis virginiana and 2 nymphs (Amblyomma cf. oblongoguttatum) infesting Nasua narica. None of the ticks collected from the vegetation tested positive for Ehrlichia sp. DNA on the basis of the 16S rRNA and dsb genes. The sequences from the larvae of Amblyomma sp. and the nymphs of A. cf. oblongoguttatum were similar to those of E. chaffeensis. The phylogenetic analysis inferred with maximum likelihood corroborated the identity as E. chaffeensis. Although the role of these tick species as vectors of E. chaffeensis is still undetermined, the presence of infected ticks in the area indicates a potential zoonotic risk.

Acari (Parasitiformes and Acariformes) From Mexico: Analysis of Their Geographical and Host Distribution in Rodentia (Cricetidae).

The study of Acari associated with cricetid rodents in Mexico began at the end of the 1930s. Despite efforts to gathering the information, only listings were built, but none of these studies present an analysis of the available data. A search was made through electronic databases; in addition, some not published records contained at Collection of Laboratorio de Acarología, Facultad de Ciencias, Universidad Nacional Autónoma de México were included in the inventory. Combining the literature records and those deposited in the collection, the total number of species of Acari associated with this family of rodents is 165, distributed in two superorders, four orders, 15 families, and 57 genera. Of the 15 families registered, the richest is Trombiculidae (70 nominal species and 75 taxa), followed by Laelapidae (39 and 42, respectively), Ixodidae (13 nominal and 16 taxa), and Leewenhoekiidae (13 nominal and taxa). From the bibliographic searches, a total of 76 papers were recovered with information on the association between Acari and cricetid rodents in Mexico. The main detected approach in the literature was taxonomic (75 works) and one on detection of pathogens. From the 145 known species of cricetids recorded in Mexico, only 72 (distributed in 18 genera) have been studied and found to host Acari. The use of regionalization of Mexico in provinces allowed us to map the records of Acari associated to cricetids in the most natural approximation of their distribution. We recognize and discuss seven factors that favor the scarcity and asymmetry of acarological studies in Mexico.

Mites, rodents, and pathogens: A global review for a multi-species interaction in disease ecology.

More than ever, there is a need to understand how pathogens, vectors and hosts occur temporally and spatially to predict the occurrence of zoonotic outbreaks. Related to this, mites of the Mesostigmata and Trombidiformes orders have the potential to transmit several diseases, yet their information of occurrence, distribution and zoonotic accompanying agents have not been systematically organized. We conducted a systematic review using a combination of words through the Sysrev platform, as well as literature searches in specialised databases to identify global patterns of infections, trends in mite-rodent-pathogen research and existing knowledge gaps. The inclusion criterion was the detection of pathogens in mites, either by molecular or serological techniques or by direct observation under the microscope, which rendered 125 papers. Most works have been carried out in Asia, mainly around the transmission of Orientia tsutsugamushi. Interestingly, co-infections, i.e., the presence of more than one pathogen in an individual, are common in other Acari groups such as ticks. Moreover, this is not the case for Trombidiformes and Mesostigmata as only 4.7 percent of the articles reviewed detected more than one pathogen in these mites. It is important to include a multi-host, multi-vector and multi-pathogen approaches to understand complex systems in disease ecology. A synergy between mite taxonomists, physicians and veterinarians, decision-makers, governmental organisations, and society is needed to address the emergence of mite-borne new or neglected diseases.

Rickettsia spp. in ticks from a tropical dry forest reserve on Mexico's Pacific Coast.

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 world. Ticks were collected during April and November 2018 and 2019, determined to species, and subsequently processed for rickettsiae. Genomic DNA was extracted from each of 349 ticks (198 from mammals, 151 from vegetation) and screened for Rickettsia by targeting the gltA and ompA genes. Overall, 75 ticks (21.5%) were positive for rickettsiae (46 from mammals, 29 from vegetation). Through BLASTn and maximum likelihood analysis, four Rickettsia taxa were identified. Only Rickettsia amblyommatis had been previously recorded in the vicinity of the EBCh, and we confirm its presence in this reserve, associated with Amblyomma mixtum, Amblyomma cf. oblongoguttatum and Amblyomma parvum. Additionally, we record for the first time at EBCh the taxa Rickettsia parkeri strain Atlantic rainforest, which is known to cause spotted fever illness in humans, detected in Amblyomma ovale; Rickettsia bellii in A. parvum and Ornithodoros talaje; and an undescribed Rickettsia sp. in Ixodes sinaloa.

Ornithodoros dyeri (Parasitiformes: Ixodida: Argasidae) parasitizing Leptonycteris yerbabuenae (Chiroptera: Phyllostomidae) in Mexico.

Parasites are a selective force that shape communities and ecosystems. Hosts represent a food source, habitat, and a way to disperse. In recent years, investigations dealing with bats and their role as hosts to numerous parasitic organisms, including metazoan ectoparasites and endoparasites have increased, and soft ticks (Parasitiformes: Ixodida: Argasidae) are among the best known. In Mexico, 16 species of soft ticks associated with bats have been reported up to now, but there are no specific records of soft ticks parasitizing Leptonycteris yerbabuenae in the country. Herein, we record for the first time the presence of Ornithodoros dyeri parasitizing L. yerbabuenae and report an extension of its geographic distribution. The same tick species was also recorded from the California leaf-nosed bat (Macrotus californicus). Data on prevalence, mean intensity, mean abundance, tick identification, and possible scenarios of life cycle associations for O. dyeri and one of its hosts, L. yerbabuenae, are discussed.

Arthropods Associated with Mammals. Their Importance as Part of the Richness in a Biosphere Reserve in Mexico.

The Chamela Biological Station (ChBS) is located in the Pacific Coast of Mexico in the State of Jalisco. This represents one of the core areas of the Chamela-Cuixmala Biosphere Reserve, characterized by one of the most threatened ecosystems, the tropical dry forest. Although accumulated knowledge of biological diversity, only few studies have been focused on ectoparasites or ectodytes associated with mammals, only 23 arthropod taxa had been recorded. In order to increase knowledge about arthropods associated with Mexican mammals, the objective of this work was to record the richness of arthropods (mites, ticks, lice, and fleas) associated with small and medium-sized mammals in the ChBS. A total of 81 hosts belonging to four orders, six families and nine species were captured. From these hosts, 4,946 arthropods were recovered: 4,007 mites, 673 ticks, 230 lice, and 36 fleas. Among medium-sized mammals, Nasua narica (L.) and Didelphis virginiana Kerr showed the highest levels of richness, with six arthropod taxa; among rodents, Heteromys pictus (Thomas) had the highest number of associated species (five). Within the 22 arthropod taxa registered in the present work, 12 represent new records for the reserve, and 3 represent new records for Mexico. With this study, the arthropod fauna associated with mammals in the ChBS has been raised to 38 taxa. In terms of biological conservation, knowledge of the species that inhabit natural reserves must be a priority, since this represents the baseline for species protected, not only in Mexico but around the world.

The soft ticks (Parasitiformes: Ixodida: Argasidae) of Mexico: species, hosts, and geographical distribution.

Distribution and host data from published literature and previously unpublished collection records are provided for all 37 species of soft ticks, family Argasidae, that are known to occur in Mexico, including Ornithodoros dugesi, which is generally regarded as a junior synonym of Ornithodoros talaje, and Ornithodoros marinkellei, a new record for Mexico. Parasite-host and host-parasite lists are presented, together with keys to adults and larvae, and a gazetteer of collection localities supplemented by maps showing each species' distribution in Mexico.

Myobiid mites (Trombidiformes, Myobiidae) of the golden bat Mimon cozumelae from Mexico. Description of the male and tritonymph of Ioanella mimon and new records of Eudusbabekia mimon.

The male and the tritonymph of Ioanella mimon are described for the first time parasitizing to Mimon cozumelae from Yucatan, Mexico. Male of Ioanella mimon is characterized by the presence of legs I with the tibia and tarsus fused forming a small complex devoided of apical claws, legs II-IV with two claws, setae vi at level of anterior end of genital plate, genital plate rounded with an anterior projection, all intercoxal setae short; while the tritonymph is characterized by the presence of legs I unequal; legs II-IV with 2-1-1 claws, and posterior region of dorsal idiosoma with 3 pairs of cylindrical and toothed setae. Additionally, we include new locality and host records for Eudusbabekia mimon which was also found on Mimon cozumelae. Both species were described originally in association with Mimon bennettii at Bartica, Guyana.