Papers by Marco Antonio Torres Castro
Revista Biomédica, 2021
Introducción. Las especies patógenas del género Leptospira ocasionan la leptospirosis en seres hu... more Introducción. Las especies patógenas del género Leptospira ocasionan la leptospirosis en seres humanos y animales susceptibles. Los roedores son los reservorios naturales de las bacterias; otros animales silvestres son hospederos accidentales. Las musarañas han sido involucradas en el ciclo de transmisión de este patógeno en varios países; sin embargo, en México, no existe información al respecto. Objetivo. Describir la infección con Leptospira spp. en musarañas capturadas en Yucatán, México. Material y métodos. Se capturaron dos ejemplares de musaraña (Cryptotis mayensis) en el municipio de Hunucmá. Ambos fueron eutanasiados para recolectar fragmentos de riñón, bazo y músculo estriado esquelético que sirvieron en la extracción de ADN total. La infección con Leptospira se exploró por PCR convencional para la amplificación de un fragmento del gen 16S ribosomal (16S rRNA). Asimismo, para corroborar y robustecer los resultados, se realizaron otras reacciones para la amplificación de fr...
Revista medica del Instituto Mexicano del Seguro Social, 2018
The aim of this editorial is to present a brief description of the Torque teno virus’ epidemiolog... more The aim of this editorial is to present a brief description of the Torque teno virus’ epidemiology and establish the actuality of their study in México. Also, we mentioned the studies made in México and Yucatán, specifically in the Center of Regional Research “Dr. Hideyo Noguchi” of the Autonomous University of Yucatán.
Parasitology International
Surveys on parasites of bats from the Americas have been conducted, but information on helminths ... more Surveys on parasites of bats from the Americas have been conducted, but information on helminths is still scarce, especially in the Neotropical region. In Mexico, there are species of bats that lack of a record for helminth species, such as members of the family Noctilionidae. The present study describes for the first time the helminths of Noctilio leporinus in Campeche, Mexico. In 2017, six specimens of N. leporinus were studied for helminths. The species identification of helminths was based on morphological studies and molecular analysis of fragments of the 28S rDNA. All bat specimens were infected for at least one helminth species. Three helminth taxa were identified: the trematode Pygidiopsis macrostomum, and the nematodes Tricholeiperia cf. proencai, and Heligmonellidae gen. sp. The morphological identification of P. macrostomum was confirmed by sequence analysis of 28S rDNA gene. The phylogeny of P. macrostomum grouped our sequence with other sequences of the same species collected in Brazil. The phylogenetic tree of Heligmonellidae gen. sp. indicated that the helminth belongs to clade formed by the species Odilia bainae, Nippostrongylus magnus and Nippostrongylus brasiliensis of the family Heligmonellidae. The phylogenetic analysis of the 28S sequences of T. cf. proencai did not show any similarity or close affinity with nematodes from which that gene has been sequenced to date. The findings of the present study increase the number of helminth species parasitizing bats in Mexico.
MANTER: Journal of Parasite Biodiversity, 2016
Anthropocommensal or synanthropic (hereafter "commensal") rodents live in close proximity to huma... more Anthropocommensal or synanthropic (hereafter "commensal") rodents live in close proximity to humans. The most important commensal species are the house mouse (Mus musculus Linnaeus, 1758), the Norway or brown rat (Rattus norvegicus [Berkenhout, 1769]), and the black or roof rat (R. rattus [Linnaeus, 1758]). In many parts of the world,
Veterinaria México OA
Cysticercus fasciolaris is the larval stage of Taenia taeniaeformis, a parasite that predominantl... more Cysticercus fasciolaris is the larval stage of Taenia taeniaeformis, a parasite that predominantly affects felines. It, however, has zoonotic significance since humans can be accidental hosts. Rodents and lagomorphs act as Intermediate hosts in this parasite’s life cycle. The aim of this study was to determine the natural occurrence of infection with Cysticercus fasciolaris in rodents from a rural area in Yucatan, Mexico. Rodents were captured in 40 dwellings and two neighboring areas of low deciduous forest. A total of 153 individuals of seven different species were captured: 65 Rattus rattus (42.5%), 44 Mus musculus (28.8%), 22 Heteromys gaumeri (14.4%), 11 Ototylomys phyllotis (7.2%), 9 Peromyscus yucatanicus (5.9%), 1 Peromyscus leucopus (0.6%), and 1 Sigmodon hispidus (0.6%). All animals were examined for evidence of parasitic liver infection. Rattus rattus was the only species to present positive Cysticercus fasciolaris infection (18.5%, 12/65). We thus concluded that there wa...
REVISTA BIOMÉDICA
Introducción. Las bacterias del género Rickettsia son agentes causales de las rickettsiosis, enfe... more Introducción. Las bacterias del género Rickettsia son agentes causales de las rickettsiosis, enfermedades zoonóticas endémicas en México. En Yucatán, ocurrió un brote en habitantes de Bolmay; sin embargo, no se identificó el probable artrópodo transmisor. Objetivo. Reportar la presencia de Rickettsia spp. en garrapatas infestando perros domésticos de Bolmay.Material y métodos. Se trabajaron 105 viales con hasta ocho garrapatas. Se extrajo ADN de los ectoparásitos, posterior a la identificación del ciclo de desarrollo vital, la diferenciación sexual, género y especie. Se realizaron dos PCR para aislar fragmentos de los genes htrA (17-kDa) y rOmpB, pertenecientes a Rickettsia spp. Los productos positivos fueron secuenciados y analizados con la herramienta BLAST y el algoritmo Megablast. Resultados. Se utilizaron 291 garrapatas de los géneros Amblyomma (55.7%, 162/291), Rhipicephalus (34%, 99/291) e Ixodes (10.3%, 30/291), y las especies: Rhipicephalus sanguineus sensu lato, Ixodes aff...
Veterinaria México OA
Toxoplasma gondii is an obligate intracellular protozoan parasite, recognized as the etiologic ag... more Toxoplasma gondii is an obligate intracellular protozoan parasite, recognized as the etiologic agent of toxoplasmosis, a zoonotic endemic disease in several countries, including Mexico. In the Yucatan State of Mexico, Toxoplasma infection has a high impact in both human and domestic animal health. Wild animals can also host zoonotic pathogens such as Toxoplasma gondii. The presence of Toxoplasma gondii DNA in roadkill wild animals in Yucatan was detected using a nested Polymerase Chain Reaction. Toxoplasma gondii DNA was identified in several organs retrieved from a Yucatan squirrel (Sciurus yucatanensis), a coatimundi (Nasua narica), and a greater grison (Galictis vittata). The amplified fragments of Toxoplasma gondii DNA were purified, sequenced, and certified by BLAST analysis. Our results confirm that Toxoplasma gondii can infect wild mammals from Yucatan, which could act as intermediate hosts and contribute to the transmission of the disease to humans and domestic animals, as w...
REVISTA BIOMÉDICA
Los roedores sinantrópicos participan en el ciclo infeccioso de numerosas enfermedades zoonóticas... more Los roedores sinantrópicos participan en el ciclo infeccioso de numerosas enfermedades zoonóticas de importancia a nivel mundial y nacional, ya sea como reservorios, hospederos intermediarios u hospederos de los ectoparásitos vectores que transmiten a los agentes etiológicos. En Yucatán, México, las especies más frecuentes son Rattus rattus y Mus musculus, los cuales han sido identificados en medios rurales, sub-urbanos y urbanos. En los últimos años en Yucatán, se han realizado distintos estudios epidemiológicos en los que se han descrito a estos roedores como positivos a diversos agentes zoonóticos de relevancia en salud pública y animal. El objetivo de la presente revisión es caracterizar los agentes infecciosos reportados en estas investigaciones, para manifestar la importancia de los roedores sinantrópicos en la diseminación y/o control de las enfermedades endémicas en la región.
Veterinaria México OA
Cysticercus fasciolaris is the larval stage of Taenia taeniaeformis, a parasite that predominantl... more Cysticercus fasciolaris is the larval stage of Taenia taeniaeformis, a parasite that predominantly affects felines. It, however, has zoonotic significance since humans can be accidental hosts. Rodents and lagomorphs act as Intermediate hosts in this parasite’s life cycle. The aim of this study was to determine the natural occurrence of infection with Cysticercus fasciolaris in rodents from a rural area in Yucatan, Mexico. Rodents were captured in 40 dwellings and two neighboring areas of low deciduous forest. A total of 153 individuals of seven different species were captured: 65 Rattus rattus (42.5%), 44 Mus musculus (28.8%), 22 Heteromys gaumeri (14.4%), 11 Ototylomys phyllotis (7.2%), 9 Peromyscus yucatanicus (5.9%), 1 Peromyscus leucopus (0.6%), and 1 Sigmodon hispidus (0.6%). All animals were examined for evidence of parasitic liver infection. Rattus rattus was the only species to present positive Cysticercus fasciolaris infection (18.5%, 12/65). We thus concluded that there wa...
Leptospira spp. is the causal agent of leptospirosis, an anthropozoonotic disease distributed wor... more Leptospira spp. is the causal agent of leptospirosis, an anthropozoonotic disease distributed worldwide. In Mexico, the disease is recognized as a human and livestock health problem. The synanthropic rodents Mus musculus and Rattus rattus constitute some of the most important reservoirs of the disease. The objective of this study was to use conventional PCR to investigate the condition of the agents of Leptospira spp. in M. musculus and R. rattus captured in a rural community in Yucatan, Mexico, and to identify the species involved in infection through sequencing and phylogenetic analysis. A total of 130 M. musculus and 57 R. rattus specimens were used.
DNA was extracted from the kidney tissue and a PCR-based test was conducted, yielding a total positivity for Leptospira spp. of 4.81% (9/187). Sequencing and phylogenetic analysis of the PCR products identified the presence of the pathogenic species L. interrogans and L. kirschneri. This study presents the first molecular evidence of infection by Leptospira spp. in synanthropic rodents in Yucatan, Mexico.
Volumen 23 (Suplemento) by Marco Antonio Torres Castro
23(Supl), 2018
Objective. To determine the presence of Rickettsia typhi in synanthropic rodents captured in the ... more Objective. To determine the presence of Rickettsia typhi in synanthropic rodents captured in the rural community of Bolmay, Yucatan, Mexico, an area with history of murine typhus cases. Materials and methods. Thirty Mus musculus, 6 Rattus rattus and 1 Heteromys gaumeri were examined. Total DNA was obtained of rodent's spleen. The identification of Rickettsia typhi was performed through the fragment's amplification of the htrA (17-kDa gene protein) by endpoint PCR. The positive products were purified and sent for sequencing and analysis with the BLAST tool. Results. Rickettsial DNA was identified in 27% (10/37) of the rodents: seven M. musculus and 3 R. rattus. The alignment analyses obtained identity and coverage percentages of 97-99% for R. typhi. Conclusions. The present study suggests the participation of synanthropic rodents in the murine typhus cycle in the region. We described the first molecular evidence of R. typhi in M. musculus of Yucatan, Mexico.
Volumen 25 Número 2 by Marco Antonio Torres Castro
Revista MVZ Córdoba, 2020
Objetivo. Reportar la infección con Leptospira en riñones de murciélagos de Campeche y Yucatán, M... more Objetivo. Reportar la infección con Leptospira en riñones de murciélagos de Campeche y Yucatán, México, a través de la amplificación por PCR de dos fragmentos distintos del gen 16S RNA ribosomal. Materiales y métodos. Se realizaron capturas en un sitio de Campeche y dos de Yucatán. A los murciélagos capturados se les aplicó la eutanasia y se les realizó una necropsia para recolectar tejido renal que se usó en la extracción de ADN total. Se realizaron dos PCR convencionales para la amplificación de los fragmentos de 16S RNA ribosomal. Se obtuvieron las secuencias de algunos productos positivos y se analizaron con herramientas bioinformáticas para identificar la especie infectante de Leptospira. Resultados. Se capturaron 69 murciélagos pertenecientes a cuatro familias y a ocho especies distintas. La familia con mayor diversidad fue Phyllostomidae con cinco especies. La especie con mayor frecuencia de captura fue Artibeus jamaicensis (41, 59.4%). Las PCR arrojaron una frecuencia global de infección de 21.7%. Las especies infectadas fueron A. jamaicensis, Pteronotus parnellii y Chiroderma villosum. El análisis bioinformático arrojó un 99.0% de identidad para Leptospira noguchii, Leptospira borgpetersenii y Leptospira santarosai. Conclusiones. Algunas especies de murciélagos de Yucatán y Campeche son portadores renales de leptospiras patógenas, por lo que podrían participar en el ciclo silvestre de transmisión en la región. La frecuencia de infección encontrada en los riñones de los murciélagos utilizados es mayor en comparación con aquellas obtenidas en otros reservorios de Yucatán y Campeche. Nuevas especies de murciélagos son reportadas como portadores de Leptospira para México.
Volumen 26 Número 2 by Marco Antonio Torres Castro
Revista MVZ Córdoba, 2021
Objective. To evidence the frequency of Leptospira spp. in blood of dogs in a rural community in ... more Objective. To evidence the frequency of Leptospira spp. in blood of dogs in a rural community in the state of Yucatan, Mexico. Materials and methods. Blood samples were collected from 120 dogs from Maxcanu, Yucatan. Characteristics such as sex, age, and breed were recorded, and owners were asked about the vaccination history. The samples were transported to the laboratory and a polymerase chain reaction diagnostic test was conducted to amplify two fragments of the 16S ribosomal gene belonging to Leptospira spp. Results. The frequency of Leptospira spp. was 1.7% (2/120; 95%CI= 0.2-5.9%). Both positive dogs were male mongrel puppies (mix of breeds) with no vaccination history. Conclusions. There was a low frequency of Leptospira spp. in the blood of the studied dogs. More epidemiological research is needed to identify the Leptospira species involved in the infection and the risk of transmission to the inhabitants or other domestic animals at the study site.
Volumen 26 Número 3 by Marco Antonio Torres Castro
Revista MVZ Córdoba, 2021
Objective. To determine the circulation of West Nile virus (WNV) in horses from the eastern Yucat... more Objective. To determine the circulation of West Nile virus (WNV) in horses from the eastern Yucatán, Mexico. Materials and Methods. For convenience, 184 horses from 23 production units in the municipalities of Tizimín and Panabá, Yucatán, were studied. A blood serum sample was obtained from each studied horse and evaluated with an immunoglobulin M antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA) to detect immunoglobulin M (IgM) against WNV. Additionally, positive reactor and suspect serum samples were analyzed by reverse transcription polymerase chain reaction (RT-PCR) to detect viral RNA. Results. Eight studied horses were seropositive (4.3%, 8/184) to WNV and two were suspects (1.1%, 2/184). All serum samples were negative by RT-PCR. Conclusions. The detection of IgM specific against WNV in the studied horses shows recent infections with the virus and indicates its circulation in eastern Yucatán, Mexico.
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Papers by Marco Antonio Torres Castro
DNA was extracted from the kidney tissue and a PCR-based test was conducted, yielding a total positivity for Leptospira spp. of 4.81% (9/187). Sequencing and phylogenetic analysis of the PCR products identified the presence of the pathogenic species L. interrogans and L. kirschneri. This study presents the first molecular evidence of infection by Leptospira spp. in synanthropic rodents in Yucatan, Mexico.
Volumen 23 (Suplemento) by Marco Antonio Torres Castro
Volumen 25 Número 2 by Marco Antonio Torres Castro
Volumen 26 Número 2 by Marco Antonio Torres Castro
Volumen 26 Número 3 by Marco Antonio Torres Castro
DNA was extracted from the kidney tissue and a PCR-based test was conducted, yielding a total positivity for Leptospira spp. of 4.81% (9/187). Sequencing and phylogenetic analysis of the PCR products identified the presence of the pathogenic species L. interrogans and L. kirschneri. This study presents the first molecular evidence of infection by Leptospira spp. in synanthropic rodents in Yucatan, Mexico.