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The tayra Eira barbara is a Neotropical mustelid considered as an endangered species by Mexican environmental authorities. Despite the considerable information available on the biology and ecology of E. barbara, little is known about its helminth fauna. Here, we provided new records of nematodes from a road-killed tayra in Calakmul, Campeche, Mexico. The species identification of nematodes was based on morphological studies and molecular analysis of fragments of the 28S gene. The tayra specimen was infected by three nematodes: Molineus sp., Physalopterinae gen. sp. and Angiostrongylus vasosum. To our knowledge, this study is the first to report the natural infection of E. barbara with Molineus sp. and Physalopterinae gen. sp. Our study provides the first nucleotide sequences of nematodes parasitizing E. barbara providing a starting point against which future studies may be compared.

The aim of this paper was to study the occurrence of helminths in Mus musculus and Rattus rattus from urban, suburban and rural settlements in Yucatán, Mexico; and to analyse the host factors (e.g. sex) related to helminths’ distribution. Helminths in a total of 279 rodents were surveyed by visual examination of the liver for metacestodes and faecal examination for helminth eggs using the formalin-ethyl acetate sedimentation technique. The cestodes Hydatigera taeniaeformis (metacestodes detected in the liver) and Hymenolepis diminuta, and the nematodes Aspiculuris sp., Nippostrongylus brasiliensis, Syphacia muris, Syphacia obvelata, and Trichuris muris were identified. In M. musculus, the prevalence of infection with T. muris and H. taeniaeformis was higher in the rural village compared to those in the suburban neighbourhood. For R. rattus, a higher prevalence of infection with H. diminuta was found in the urban site compared to that in the suburban site. This study reports the occurrence of H. diminuta among rodents living in close proximity to humans, representing a potential public health risk. In addition, this survey increases our understanding of dynamic transmission among intestinal helminths recorded in Yucatán, Mexico.

Toxoplasma gondii is an obligate intracellular parasite recognized as the etiological agent of Toxoplasmosis, a zoonotic disease endemic in different countries worldwide. In Mexico, the disease is recognized as a human and animal health problem. T. gondii sporozoites have the capacity of been released from the gut lumen and infect several tissues, including kidneys. Rodents have been identified as intermediate hosts of T. gondii; nevertheless, no previous reports exist in Yucatan, Mexico, about their role in the infectious cycle. A total of 187 specimens (130 Mus musculus and 57 Rattus rattus) were studied. Total DNA was extracted from renal tissue and was utilized in the identification of T. gondii with the end-point Polymerase Chain Reaction (PCR) method. Six positive products were purified and sequenced in order to confirm and validate the results through the BLAST Sequence Analysis Tool. The PCR provided a global positivity of 5.34% (10/187). The BLAST analysis found a direct homology for T. gondii with identities and coverage of 96-98% and 98-100%, respectively. Our results confirm the role of M. musculus and R. rattus in the biological cycle of T. gondii and offer knowledge of the parasite transmission in intermediary hosts of the region. Toxoplasma gondii est un parasite intracellulaire obligatoire et l'agent causal de la toxoplasmose, une zoonose endémique dans différents pays. Au Mexique, la maladie est reconnue comme un problème de santé humaine et animale. Les sporozoïtes de T. gondii peuvent être libérés de la lumière intestinale et infecter différents tissus, dont les reins. Bien que les rongeurs soient reconnus comme des hôtes intermédiaires de T. gondii, il n'existe aucune étude sur leur rôle dans le cycle d'infection dans la région du Yucatan au Mexique. Au total, 187 spécimens (130 Mus musculus et 57 Rattus rattus) ont été étudiés. L'ADN total a été extrait du tissu rénal et utilisé pour l'identification de T. gondii par PCR. Six amplicons ont été purifiés et séquencés afin de confirmer et valider les résultats en utilisant l'outil d'analyse de séquences BLAST. La PCR a donné une positivité globale de 5.34% (10/187). L'analyse BLAST a donné une homologie directe avec T. gondii, avec des identités et couvertures de 96-98% et 98-100%, respectivement. Nos résultats confirment le rôle de M. musculus et R. rattus dans le cycle biologique de T. gondii et apportent de la connaissance quant à la transmission du parasite dans des hôtes intermédiaires de la région. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examinate the dynamics of Home Range (HR) and the social behaviour of Heteromy sgaumeri in the semidesiduos tropical forest of the south of Yucatan. We used the mark-and-release technique during four nights per month, from January 2000 to December 2001. Thirty four percent (n=174) of the total population was resident being 49% males and 51% females. The females had longer residence than the males (p<0.05). For both sexes home range (HR) and maximum distance moved (MDM) (p<0.05) were higher for adults than for yuongs, seasonality did not affect them (p>0.05). Reproductive females were territorial and had lower HR and MDM than no reproductive females (p<0.05). Males and females had similar HR (p>0.05), males did not show territoriality. The total overlapping of HR was low for both sexes and both reproductive conditions. In the rain season reproductive males had a higher overlapping percentage than that of reproductive females (p<0.05). The results suggest that H. gaumeri is a social species with a promiscuous mate system. [ABSTRACT FROM AUTHOR]

The article provides information on a study which investigated the possible use of snail species as food by Heteromys gaumeri in a subdeciduous tropical forest in the state of Yucatan, Mexico. All the species of Heteromyidae family are said to be granivorous and are endemic to the biotic province of the Yucatan Peninsula, Mexico. In the study, two grids were used as well as the mark-and-release technique.

The black rat Rattus rattus and the house mouse Mus musculus are two commensal rodent species that harbour and shed zoonotic pathogens, including helminths. The aim of this survey was to study the helminth community and the patterns of infections in R. rattus and M. musculus from two Mayan communities in Mexico. Gastrointestinal helminths were isolated from 322 M. musculus and 124 R. rattus, including Gongylonema neoplasticum, Hassalstrongylus aduncus, Hassalstrongylus musculi, Hydatigera taeniaeformis metacestode, Hymenolepis diminuta, Nippostrongylus brasiliensis, Oligacanthorhynchidae gen. sp., Syphacia muris, Syphacia obvelata, Rodentolepis microstoma and Trichuris muris. The overall richness of helminths was seven in R. rattus and six in M. musculus. The results of generalized linear models showed that juvenile rodents had lower probabilities of being infected with G. neoplasticum, H. taeniaeformis and H. musculi than adult rodents. A positive association between the prevalence of S. muris and rat abundance was found. The intensity of infection with S. muris was higher in the rainy season than in the dry season; the opposite result was found for H. musculi infection. Male R. rattus harboured more S. muris specimens. The intensity of infection with T. muris was inversely associated with mouse abundance. The presence of the zoonotic H. diminuta, as well as H. taeniaeformis and R. microstoma in rodent populations indicates that there is risk of transmission, and that their entire life cycle occurs in the study area.

The aim of the present study was to calculate the prevalence and intensity of intestinal helminths in the house mouse (Mus musculus) and the black rat (Rattus rattus) trapped in rural households of Yucatan, Mexico. Sampling was conducted during the rainy season from October to December 2011 and the dry season from January to March 2012. A total of 154 M. musculus and 46 R. rattus were examined, with 84.2% of M. musculus being infected with helminths compared with a significantly lower prevalence of 52.2% in R. rattus (P< 0.01). Adult M. musculus were more likely to be infected with helminths (89%) than subadults (63%) (P< 0.01). Four helminth species were identified: Taenia taeniaeformis larvae, Nippostrongylus brasiliensis, Syphacia muris and Trichuris muris. Nippostrongylus brasiliensis was present more frequently in M. musculus than in R. rattus (P< 0.01) and in adult mice compared to subadults (P< 0.01). Trichuris muris was present only in adult mice. This is the first report of N. brasiliensis, S. muris and T. muris in Yucatan, Mexico, as well as the first to report the presence of N. brasiliensis in M. musculus from Mexico. The helminth fauna of commensal rodents present in households appears to constitute a low potential health risk to local inhabitants; however, it would be advisable to conduct further studies to better understand the public health risk posed by these rodent intestinal helminths.

Cysticercus fasciolaris is the larval stage of the cestode Taenia taeniaeformis, whose definitive hosts are mainly cats. This larval stage uses a wide variety of small rodents, and occasionally birds and humans, as intermediate hosts. In the Yucatan, there are no reports of the presence of this cestode in animal populations. The aim of this study was to evaluate the occurrence of C. fasciolaris in rodent populations from the Cuxtal ecological reserve, Yucatan, Mexico. Trapping of rodents was conducted from October 2009 to April 2010 in 40 households in Molas, in which Sherman traps were placed both inside and outside backyards. Rodents were dissected to inspect the liver for the presence of the worm. To determine risk factors associated with infection, univariate analysis was performed using sex, age, species, trapping site, and season as independent variables. Variables with a P value <  0.2 were analysed using a logistic regression model. In this study, 411 individuals of six rodent species were trapped; Mus musculus was the most abundant (78%), followed by Rattus rattus (13%) and the wild species Peromyscus yucatanicus, Ototylomys phyllotis, Heteromys gaumeri and Reithrodontomys gracilis (9%). Only 7.5% (n = 31) of M. musculus and R. rattus were infected with C. fasciolaris (demonstrated by the presence of liver cysts) with a prevalence of 9.0% and 3.5%, respectively. Both adults and male mice were 4.33 and 3.46 (OR values) times more likely to have C. fasciolaris than juveniles and females respectively. We can conclude that in the Cuxtal Reserve, Yucatan, Mexico, the prevalence of C. fasciolaris is higher in M. musculus, and that adult males had a higher probability of infection. Wild species, mainly P. yucatanicus, were not found to be infected with the cestode, but its presence in the backyards of households could result in a potential risk of acquiring this infection.