Identification of SARS-CoV-2 in urban rodents from Southern Mexico City at the beginning of the COVID-19 pandemic.

Currently, there are some concerns about the situation and, in particular, about the future of the COVID-19 pandemic and the new emerging variants of SARS-CoV-2. Rodents are an example of synanthropic animals in urban environments that harbor important zoonoses. Although the molecular identification of SARS-CoV-2 in Rattus norvegicus from New York City had been reported, in other studies, urban wild rodents infected with this virus have not been found. This study aimed to molecularly identify the presence of SARS-CoV-2 in urban wild rodents from Mexico City, trapped along a water channel of a public park as part of a pest control program, at the beginning of the COVID-19 pandemic, during the fall and winter of 2020. Up to 33 Mus musculus and 52 R. norvegicus were captured and euthanized, large intestine samples with feces from the animals were obtained. RNAs were obtained and subjected to qRT-PCR for SARS-CoV-2 identification and threshold cycle (Ct) values were obtained. Four mice (12.1%) and three rats (5.8%) were positive, three rodents exhibited Ct<30. Our results on the frequency of SARS-CoV-2 in urban rats are in line with other previous reports. Thus, similar to other authors, we suggest that surveillance for the detection of SARS-CoV-2 in urban wild rodents, as sentinel animals, should be maintained.

Search for antibodies against Trichinella in two synanthropic Procyonidae species from southeast Mexico: white-nosed coatis (Nasua narica) and raccoons (Procyon lotor).

Trichinella is a nematode that are spread by the consumption of parasitized meat. Carnivora, a mammalian order, serve as key hosts for this parasite. However, evidence of Trichinella in wildlife from the Neotropics is extremely scarce, with reports documenting its presence only for five carnivore species: two Felidae, one Otariidae and two Mustelidae. Other widely distributed species that are consumed as bushmeat, such as Procyonidae, have not been studied in this context. A long-term study was performed for antibodies against Trichinella in coatis (Nasua narica) and common raccoons (Procyon lotor) in southeastern Mexico. Between the summer of 2009 to the winter 2013, a total of 291 coati samples and 125 raccoon samples were collected from a tropical green area located within an urban zone. An Enzyme-linked immunosorbent assay (ELISA) was used to detect antibodies against the excretory and secretory products of Trichinella spiralis muscle larva. ELISA-positive samples were further confirmed by Western Blot analysis. Results showed no evidence of antibodies during the first two years of study. However, in 2011, a sudden appearance of anti-Trichinella occurred. The seroprevalence reached its highest peak of 43% for coatis during winter 2013 and 53% for raccoons in summer 2013. This is the first study that provides evidence of Trichinella circulation within a neotropical procyonid community.

Identification of SARS-CoV-2 in urban rodents from Southern Mexico City at the beginning of the COVID-19 pandemic

ABSTRACT Currently, there are some concerns about the situation and, in particular, about the future of the COVID-19 pandemic and the new emerging variants of SARS-CoV-2. Rodents are an example of synanthropic animals in urban environments that harbor important zoonoses. Although the molecular identification of SARS-CoV-2 in Rattus norvegicus from New York City had been reported, in other studies, urban wild rodents infected with this virus have not been found. This study aimed to molecularly identify the presence of SARS-CoV-2 in urban wild rodents from Mexico City, trapped along a water channel of a public park as part of a pest control program, at the beginning of the COVID-19 pandemic, during the fall and winter of 2020. Up to 33 Mus musculus and 52 R. norvegicus were captured and euthanized, large intestine samples with feces from the animals were obtained. RNAs were obtained and subjected to qRT-PCR for SARS-CoV-2 identification and threshold cycle (Ct) values were obtained. Four mice (12.1%) and three rats (5.8%) were positive, three rodents exhibited Ct<30. Our results on the frequency of SARS-CoV-2 in urban rats are in line with other previous reports. Thus, similar to other authors, we suggest that surveillance for the detection of SARS-CoV-2 in urban wild rodents, as sentinel animals, should be maintained.

3D wildlife skull models for wildlife veterinary training.

Wildlife veterinarians are necessary for zoonotic diseases and species loss management, and there is a rising interest to enroll at veterinary schools with the wish to work in zoo and wildlife medicine. However, teaching wildlife is challenging due to the difficulty faced by universities to work with wild animal specimens. The aim of the present was to evaluate the understanding efficiency of some anatomical and behavioral aspects using 3D printed models of four wildlife species skulls, the kinkaju (Potos flavus), the white-nosed coati (Nasua narica), the northern anteater (Tamandua mexicana), and the nine-banded armadillo (Dasypus novemcinctus). This study was performed on 85 third-year veterinary students, divided into an experimental and a control group, who used and not used 3D printed skulls, respectively. Results show that the experimental group shows higher scores, in three of the four variables evaluated, than the control group. Then, 3D wildlife printed skulls constitute a promising teaching tool for veterinary students. In fact, it may be as good as real skulls, since new 3D printers can print on high endurance and firmness stock with high accuracy at reduced costs. In this context, it is important to encourage its use for the training of new generations and keep professionals up to date.

Novel Francisella-like endosymbiont and Anaplasma species from Amblyomma nodosum hosted by the anteater Tamandua Mexicana in Mexico.

The microbiome represents a complex network among the various members of the community of microorganisms that are associated with a host. The composition of the bacterial community is essential to supplement multiple metabolic pathways that the host lacks, particularly in organisms with blood-sucking habits such as ticks. On the other hand, some endosymbionts showed some competence with potentially pathogenic microorganisms. Francisella-like endosymbionts (FLEs) encompass a group of gamma-proteobacterias that are closely related to Francisella tularensis, but are usually apathogenic, which brings nutrients like vitamin B and other cofactors to the tick. It has been postulated that the main route of transmission of FLE is vertical; however, evidence has accumulated regarding the possible mechanism of horizontal transmission. Despite growing interest in knowledge of endosymbionts in the Neotropical region, the efforts related to the establishment of their inventory for tick communities are concentrated in South and Central America, with an important gap in knowledge in Mesoamerican countries such as Mexico. For this reason, the aim of this work was to evaluate the presence and diversity of endosymbionts in the highly host-specialized tick Amblyomma nodosum collected from the anteater Tamandua mexicana in Mexico. We analysed 36 A. nodosum for the presence of DNA of endosymbiont (Coxiella and Francisella) and pathogenic (Anaplasma, Borrelia, Ehrlichia and Rickettsia) bacteria. The presence of a member of the genus Francisella and Candidatus Anaplasma brasiliensis was demonstrated. Our findings provide information on the composition of A. nodosum's microbiome, increasing the inventory of bacterial species associated with this hard tick on the American continent.

New records, and molecular detection of vector-borne pathogens in Felicola subrostratus from eastern Mexico.

The study of lice associated with domestic cats is a neglected area of veterinary parasitology. In particular, the presence of the cat louse Felicola subrostratus, a small Ischnoceran species found in the fur of the domestic cat, is rarely recognized. In America, this species has been reported across six countries. Although it was also recently reported in Mexico, no studies on the molecular identification of the specimens or the monitoring of potential bacterial, and protozoan pathogens have been carried out. Thus, this work aimed to collect, and identify lice associated with domestic and free ranging cats from the states of Veracruz and Tabasco, using amplification and sequencing of the mitochondrial cytochrome c oxidase subunit I (COI), and the ribosomal 18S rDNA genes, and to monitor selected vector-borne bacterial (Bartonella, Mycoplasma, and Rickettsia) and protozoan (Babesia, and Hepatozoon) agents. Only entire lice were used for molecular host and pathogen identification. Eighty-one lice, identified as F. subrostratus, were recovered from five infested cats, and 30 were selected for molecular identification and pathogen surveillance. Analysis of the COI and 18S rDNA partial sequences showed a similarity of 96.79%-100% with sequences of F. subrostratus from the US. Mycoplasma haemofelis and Hepatozoon canis DNA was detected in three and four samples, respectively. This work provides new collection locations for F. subrostratus, and the first sequences of the COI and 18S rDNA genes from Mexico. It also reports two pathogenic microorganisms found in the lice.

Identification of Blastocystis sp. in school children from a rural Mexican village: subtypes and risk factors analysis.

Blastocystis sp. is a common eukaryotic microorganism that colonizes the intestinal tract of several animals, including humans, although its role as a pathogen is still unclear. In the present study, we report the prevalence and risk factors associated with Blastocystis infection in scholars from a rural community in Mexico. A cross-sectional observational study was carried out on schoolchildren aged 3 to 15 years old; fecal samples were analyzed by culture, Faust technique, and molecular analysis. In addition, a structured questionnaire was applied to identify possible risk factors. Of the 177 samples obtained, Blastocystis sp. was the microorganism that presented the highest frequency (n=78, 44%), and included the following subtypes (STs): ST1 (n=43, 56.5%), ST2 (n=18, 23.6%), and ST3 (n=15, 19.7%); Blastocystis STs were not identified in two cases. No associating factors were found between Blastocystis infection or among STs vs. symptoms. During bivariate analysis, no statistically significant risk factors were found, except for the variable of "eating sweets, snacks, and handmade food on the way home" (p=0.04). Therefore, it is plausible to conclude that schoolchildren become infected with Blastocystis sp. mainly outside their homes, perhaps by eating contaminated handmade food on their way to or from school; however, this variable should be evaluated in detail in future studies.

Rabies virus in white-nosed coatis (Nasua narica) in Mexico: what do we know so far?

Rabies is a neglected disease that affects all mammals. To determine the appropriate sanitary measures, the schedule of preventive medicine campaigns requires the proper identification of the variants of the virus circulating in the outbreaks, the species involved, and the interspecific and intraspecific virus movements. Urban rabies has been eradicated in developed countries and is being eradicated in some developing countries. In Europe and North America, oral vaccination programs for wildlife have been successful, whereas in Latin America, Asia, and Africa, rabies remains a public health problem due to the habitation of a wide variety of wild animal species that can act as rabies virus reservoirs in their environment. After obtaining recognition from the WHO/PAHO as the first country to eliminate human rabies transmitted by dogs, Mexico faces a new challenge: the control of rabies transmitted by wildlife to humans and domestic animals. In recent years, rabies outbreaks in the white-nosed coati (Nasua narica) have been detected, and it is suspected that the species plays a significant role in maintaining the wild cycle of rabies in the southeast of Mexico. In this study, we discussed cases of rabies in white-nosed coatis that were diagnosed at InDRE (in English: Institute of Epidemiological Diagnosis and Reference; in Spanish: Instituto de Diagnostico y Referencia Epidemiologicos) from 1993 to 2022. This study aimed to determine whether white-nosed coatis might be an emergent rabies reservoir in the country. A total of 13 samples were registered in the database from the Rabies laboratories of Estado de Mexico (n = 1), Jalisco (n = 1), Quintana Roo (n = 5), Sonora (n = 1), and Yucatan (n = 5). Samples from 1993 to 2002 from Estado de Mexico, Jalisco, and Sonora were not characterized because we no longer had any samples available. Nine samples were antigenically and genetically characterized. To date, coatis have not been considered important vectors of the rabies virus. The results from our research indicate that the surveillance of the rabies virus in coatis should be relevant to prevent human cases transmitted by this species.

Hematologic parameters and the effect of hemoparasites of wild anurans in Northern Sinaloa, Mexico.

BACKGROUND: Few hematologic profiles for free-ranging amphibians are available. Hematologic evaluation is a useful tool for determining the health of amphibian populations and providing further knowledge for conservation actions. OBJECTIVES: Hematologic variables and the presence and effect of hemoparasites in anuran species were evaluated in Northern Sinaloa, Mexico. METHODS: Blood samples were collected from wild anurans of eight species to perform blood cell counts, leukocyte differential counts, and serum protein concentrations using manual methods and refractometry. In addition, morphologic identification and quantification of the hemoparasites were performed on blood smears. RESULTS: Differences were observed by sex, age, and season for the hematologic values of Incilius alvarius (n = 23), Incilius mazatlanensis (n = 46), Rhinella horribilis (n = 64), Leptodactylus melanonotus (n = 46), Lithobates forreri (n = 135), Lithobates catesbeianus (n = 20), Smilisca fodiens (n = 42), and Scaphiopus couchii (n = 7). Intra- and extra-erythrocytic hemoparasites were found in 56.2% of amphibian hosts; the hemoparasite infection of R. horribilis and L. melanonotus was higher in the dry season, showing increases in erythroplastids and monocytes. For L. forreri, males were more infected than females, and increases in leukocytes were associated with infections of different types of hemoparasites species. CONCLUSIONS: Hematologic values, hemoparasite prevalence, and the response to hemoparasite infection vary among amphibian species, sex, and age, as well as on season and hemoparasite type. This highlights the importance of hematologic evaluations in wild amphibian populations to determine the subclinical effects of hemoparasite infections.

Trypanosoma cruzi, beyond the dogma of non-infection in birds.

Trypanosoma cruzi is a protozoan parasite responsible for Chagas disease affecting seven million people. The disease cycle is maintained between Triatominae insects and Mammalia hosts; a refractory effect against infection was noted in birds, but only verified in poultry. This paper presents a new host record for T. cruzi, the American barn-owl (Tyto furcata). Trypanosoma cruzi DTU II molecular evidence was found in heart, intestine, liver, and breast suggesting an established chronic infection based on the parasite DNA presence in multiple organs but absent in spleen, as in the murine model and chronically infected raccoons (Procyon lotor). For birds, the parasite rejection was explained based on the complement and high body temperature, but these mechanisms vary greatly among the members of the avian class. Therefore, there is a need to investigate whether more bird species can become infected, and if T. furcata has a role in disseminating, transmitting and/or maintaining the parasite.

The mitochondrial activity of leukocytes from Artibeus jamaicensis bats remains unaltered after several weeks of flying restriction.

Bats are the only flying mammals known. They have longer lifespan than other mammals of similar size and weight and can resist high loads of many pathogens, mostly viruses, with no signs of disease. These distinctive characteristics have been attributed to their metabolic rate that is thought to be the result of their flying lifestyle. Compared with non-flying mammals, bats have lower production of reactive oxygen species (ROS), and high levels of antioxidant enzymes such as superoxide dismutase. This anti-oxidative vs. oxidative profile may help to explain bat's longer than expected lifespans. The aim of this study was to assess the effect that a significant reduction in flying has on bats leukocytes mitochondrial activity. This was assessed using samples of lymphoid and myeloid cells from peripheral blood from Artibeus jamaicensis bats shortly after capture and up to six weeks after flying deprivation. Mitochondrial membrane potential (Δψm), mitochondrial calcium (mCa2+), and mitochondrial ROS (mROS) were used as key indicators of mitochondrial activity, while total ROS and glucose uptake were used as additional indicators of cell metabolism. Results showed that total ROS and glucose uptake were statistically significantly lower at six weeks of flying deprivation (p < 0.05), in both lymphoid and myeloid cells, however no significant changes in mitochondrial activity associated with flying deprivation was observed (p > 0.05). These results suggest that bat mitochondria are stable to sudden changes in physical activity, at least up to six weeks of flying deprivation. However, decrease in total ROS and glucose uptake in myeloid cells after six weeks of captivity suggest a compensatory mechanism due to the lack of the highly metabolic demands associated with flying.

Natural co-infection of divergent hepatitis B and C virus homologues in carnivores.

In humans, co-infection of hepatitis B and C viruses (HBV, HCV) is common and aggravates disease outcome. Infection-mediated disease aggravation is poorly understood, partly due to lack of suitable animal models. Carnivores are understudied for hepatitis virus homologues. We investigated Mexican carnivores (ringtails, Bassariscus astutus) for HBV and HCV homologues. Three out of eight animals were infected with a divergent HBV termed ringtail HBV (RtHBV) at high viral loads of 5 × 109 -1.4 × 1010 copies/ml serum. Two of the RtHBV-infected animals were co-infected with a divergent hepacivirus termed ringtail hepacivirus (RtHV) at 4 × 106 -7.5 × 107 copies/ml in strain-specific qRT-PCR assays. Immunofluorescence assays relying on HBV core and RtHV NS3/4a proteins indicated that none of the animals had detectable hepadnavirus core-specific antibodies, whereas one RtHV-infected animal had concomitant RtHV-specific antibodies at 1:800 end-point titre. RtHBV and RtHV complete genomes showed typical HBV and HCV structure and length. All RtHBV genomes were identical, whereas RtHV genomes showed four amino acid substitutions located predominantly in the E1/E2-encoding genomic regions. Both RtHBV (>28% genomic nucleotide sequence distance) and RtHV (>30% partial NS3/NS5B amino acid sequence distance) formed new species within their virus families. Evolutionary analyses showed that RtHBV grouped with HBV homologues from different laurasiatherian hosts (carnivores, bats, and ungulates), whereas RtHV grouped predominantly with rodent-borne viruses. Ancestral state reconstructions showed that RtHV, but not RtHBV, likely emerged via a non-recent host switch involving rodent-borne hepacivirus ancestors. Conserved hepatitis virus infection patterns in naturally infected ringtails indicate that carnivores may be promising animal models to understand HBV/HCV co-infection.

Viral Prevalence in Wild Serval Population is Driven by Season and Sex.

One of the key factors influencing the population dynamics of threatened species such as felids is disease, but long-term studies of the factors influencing seroprevalence of wild felids are extremely rare, hindering conservation efforts. We set out to determine seroprevalence of six viral diseases (feline panleukopenia virus, feline leukemia virus, feline coronavirus, feline calicivirus, feline herpes virus, and feline immunodeficiency virus) among a population of serval (Leptailurus serval) with an extremely high density in South Africa. We captured 55 individuals over four years and screened blood samples for antibodies to each virus. We found that seroprevalence were high (ranging from 30.0% positive for a single virus to 1.8% positive for up to five viruses) and that seroprevalence was influenced by season and sex, but not body condition. We suggest further monitoring of this population and recommend that long-term studies are conducted for serval and other felids to determine whether these trends are representative on a broader scale.

The genus Rickettsia in Mexico: Current knowledge and perspectives.

The genus Rickettsia encompasses 35 valid species of intracellular, coccobacilli bacteria that can infect several eukaryotic taxa, causing multiple emerging and re-emerging diseases worldwide. This work aimed to gather and summarise the current knowledge about the genus Rickettsia in Mexico, updating the taxonomy of the bacteria and their hosts by including all the records available until 2020, to elucidate host-parasite relationships and determine the geographical distribution of each Rickettsia species present in the country. Until now, 14 species of Rickettsia belonging to four groups have been recorded in Mexico. These species have been associated with 26 arthropod species (14 hard ticks, three soft ticks, two sucking lice, and seven fleas) and 17 mammal species distributed over 30 states in Mexico. This work highlights the high biological inventory of rickettsias for Mexico and reinforces the need to approach the study of this group from a One Health perspective.

Assessing the SARS-CoV-2 threat to wildlife: Potential risk to a broad range of mammals.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect animals, however, the whole range of potential hosts is still unknown. This work makes an assessment of wildlife susceptibility to SARS-CoV-2 by analyzing the similarities of Angiotensin Converting Enzyme 2 (ACE2) and Transmembrane Protease, Serine 2 (TMPRSS2)-both recognized as receptors and protease for coronavirus spike protein-and the genetic variation of the viral protein spike in the recognition sites. The sequences from different mammals, birds, reptiles, and amphibians, and the sequence from SARS-CoV-2 S protein were obtained from the GenBank. Comparisons of aligned sequences were made by selecting amino acids residues of ACE2, TMPRSS2 and S protein; phylogenetic trees were reconstructed using the same sequences. The species susceptibility was ranked by substituting the values of amino acid residues for both proteins. Our results ranked primates at the top, but surprisingly, just below are carnivores, cetaceans and wild rodents, showing a relatively high potential risk, as opposed to lab rodents that are typically mammals at lower risk. Most of the sequences from birds, reptiles and amphibians occupied the lowest ranges in the analyses. Models and phylogenetic trees outputs showed the species that are more prone to getting infected with SARS-CoV-2. Interestingly, during this short pandemic period, a high haplotypic variation was observed in the RBD of the viral S protein, suggesting new risks for other hosts. Our findings are consistent with other published results reporting laboratory and natural infections in different species. Finally, urgent measures of wildlife monitoring are needed regarding SARS-CoV-2, as well as measures for avoiding or limiting human contact with wildlife, and precautionary measures to protect wildlife workers and researchers; monitoring disposal of waste and sewage than can potentially affect the environment, and designing protocols for dealing with the outbreak.

Canine distemper in neotropical procyonids: Molecular evidence, humoral immune response and epidemiology.

Canine Distemper Virus (CDV) can produce a fatal multisystem disease in carnivores and other mammals and is an important threat for wildlife conservation. However, integrative and comparative studies in wild carnivores are scarce and some areas of the world lack of genetic studies. We explore the dynamic of host-CDV in a procyonid community during an outbreak. This study reports for the first time an index case occurred in a common raccoon (Procyon lotor) and for which a complete CDV diagnosis was performed. The long-term epidemiological analysis in two sympatric populations of common raccoons and white-nosed coatis (Nasua narica) was achieved through seroneutralization, RT-PCR and direct immunofluorescence assays. Additionally, hematologic analyses were performed and phylogenetic reconstruction of CDV was done using molecular data from this study. Overall prevalence for white-nosed coatis was 19.6 % and for common raccoons was 25.3 % by seroneutralization, and 13.3 % and 17.3 % by RT-PCR. Antibodies titer average for white-nosed coatis was 1:512 and 1:156 for common raccoons. Significant difference in prevalence between white-nosed coatis and common raccoons was detected during one season (summer 2013). White-nosed coatis showed differences in erythrocytes and monocytes counts between positives and negative animals. A 100 % similarity was found between CDV of white-nosed coati and CDV of common raccoon and is a new CDV sequence not previously described; this sequence is close to Asian and European lineage. An endemic state of distemper in both species was observed but showed different dynamics over time per host species. Differences in cellular and humoral responses were also detected between procyonids. The evidence found here may have serious implications for CDV understanding in wild carnivores, it reveals clear differences in the response over time to the same CDV strain, in two close related carnivore species.

RADIOGRAPHIC ANATOMY OF THE FORELIMB IN THE NORTHERN TAMANDUA (TAMANDUA MEXICANA).

The thoracic limb anatomy of anteaters in the family Myrmecophagidae is specialized for accessing termite and ant nests and for defense purposes. In the case of the northern tamandua (Tamandua mexicana), the forelimbs are also adapted for arboreal and terrestrial locomotion. Unfortunately, this species faces many conservation threats, such as habitat loss and traffic accidents, and injured individuals are frequently taken to wildlife rehabilitation centers. However, lack of knowledge of the radiographic osteoanatomy of this species may prevent appropriate management of injuries and thereby reduce the chances of successful release and survival. In order to fill this knowledge gap, this article describes for the first time the radiographic anatomy of the thoracic limb of the northern tamandua using four standard views and one additional view. The additional orthogonal view helps visualize structures, such as the hamatus process and the sesamoid bone, that are otherwise difficult to visualize due to the natural forearm position of anteaters. Additionally, some fractures and physeal growth plates were identified in one juvenile individual. Further radiographic investigations should be conducted on anteaters to provide more tools for diagnosis, treatment, and rehabilitation of these animals.

Prevalence and Epitope Recognition of Anti-Trypanosoma cruzi Antibodies in Two Procyonid Species: Implications for Host Resistance.

More than 180 mammalian species have been found naturally infected with Trypanosoma cruzi. Many of them play an important role in the maintenance of this parasite. In particular, new studies have appeared which indicate that some species of Procyonidae family may play a role as T. cruzi hosts, however, more data are needed to evaluate their long-term physiological response to parasite infection, especially for specific antibodies. In this study, antibodies to T. cruzi were detected and prevalence and epitope recognition were assessed by ELISA (using discrete typing unit (DTU) I as antigen) and WB (using DTU I and DTU II as antigens) and sera from two procyonid species obtained through five-year follow-up of two semicaptive populations living in the same habitat. Marked heterogeneity in antigens recognition between species and differences in seroprevalence (p = 0.0002) between white-nosed coatis (Nasua narica), 51.8% (115/222), and common raccoons (Procyon lotor), 28.3% (23/81), were found. Antigens with high molecular weight when DTU-I was used were the most recognized, while a greater antigen diversity recognition was observed with DTU-II; for white-nosed coatis, low-molecular-weight antigens were mainly recognized, while for common raccoons proteins with molecular weights greater than 80 kDa were recognized most. These divergent humoral immune responses could be related to an alleged pattern of recognition receptors and major histocompatibility complex molecules difference in the procyonids species.

Morphological and molecular characteristics of hemoparasites in vaillant's frogs (Lithobates vaillanti).

Amphibian populations are declining around the world, and the main reasons are the environmental changes and pathogens. However, there are few studies addressing the interaction and impact of the different pathogens that affect amphibians, such as hemoparasites. These parasites had been described as common in some amphibian species, but unfortunately, their description and characterization are unclear and scarcely spread. The objective of the present study was to evaluate the morphological and molecular characterization of hemoparasites present in vaillant's frogs. Seven frogs of Lithobates vaillanti were captured at the biological station La Florida in Tabasco, Mexico. Blood smears were performed, and results show that 100% of the animals have hemoparasites. Three types of hemoparasites were found. Eighty-five percent of the frogs were positive to Hepatozoon sp., 57% to Lankesterella sp., and 28% to Trypanosoma sp. According to the molecular analysis of the obtained sequences of Trypanosoma sp. and Hepatozoon sp., both protozoans were positioned in between the clusters of parasites of different geographical regions. Nevertheless, no species names were assigned to any of these parasites because more sequences and analysis are needed.

Molecular genotyping of Blastocystis spp. in wild mammals from Mexico.

Blastocystis spp. are common intestinal parasites found worldwide in humans and a wide range of animals. They exhibit extensive genetic diversity; currently, 17 subtypes (STs) and some groups called non-mammalian and avian STs (NMASTs) have been proposed. In addition, a large variety of animals have been reported as hosts of the parasite, and new hosts and STs are still being described. In this study, Blastocystis infection of wild animals in two sylvatic areas of Mexico was surveyed. Of one hundred twenty-four fecal samples, six were positive for Blastocystis: specifically, one sample from an opossum, one sample from a bat, and four samples from different species of rodents. ST4, ST17, and nucleotide sequences similar to Blastocystis lapemi were identified based on SSU rDNA sequences. To our knowledge, this is the first report to investigate species poorly or not previously evaluated for Blastocystis infection. Mammals having different niches and geographical distribution were infected with similar genetic type of Blastocystis, so that we suggest that local water or food sources could play an important role in Blastocystis transmission and ST maintenance in wild animals. Additionally, there are STs with scarce genetic variation, suggesting that they could be highly adapted to their hosts. These data contribute to our understanding of the host range and genetic diversity of Blastocystis.