Bartonella rochalimae in a flea collected from a Mephitis macroura in Sonora Mexico.

PURPOSE: At least thirty species of wild carnivores have been recorded harboring Bartonella, and one of the most common pathogenic species infecting them is Bartonella rochalimae, which can cause endocarditis in humans and dogs. This bacterium can infect various mammals including wild carnivores, as well as ectoparasitic vectors such as fleas and ticks. Here we report the presence of B. rochalimae, in a Pulex simulans flea collected from a Mephitis macroura skunk in the municipality of Santa Cruz in Sonora, Mexico. METHODS: Fleas were collected from a M. macroura in Sonora, Mexico, in October 2019. They were identified to species level and subsequently tested for the presence of Bartonella using molecular tools including conventional PCR, sequencing, and phylogenetic analysis. RESULTS: A total of 10 P. simulans fleas (one male, nine females) were collected from the M. macroura skunk. The PCR and phylogenetic analysis indicated a prevalence of 10% (1/10) and a sequence clustered with the clade of B. rochalimae. CONCLUSIONS: We confirmed the presence of B. rochalimae in a P. simulans flea collected from a M. macroura skunk in the area of Santa Cruz, Sonora, Mexico. Based on our results and previous studies in northern Mexico, which are consistent, it is necessary to continue monitoring Bartonella in M. macroura skunks and their fleas, since they could be important reservoirs of this bacterium in northern Mexico.

Diversity and Genetic Structure of Scarlet Plume (Euphorbia fulgens), an Endemic Plant of Mexico.

Euphorbia fulgens is an ornamental species cultivated in Europe and endemic to Mexico; its ecological, genetic, and evolutionary aspects are not known. The objectives of this study were to determine its distribution, describe the places it inhabits, and analyze the diversity and genetic structures of wild populations of E. fulgens. A bibliographic review of the herbarium specimens and a field evaluation were carried out to develop a potential distribution map based on a multi-criteria analysis of the climatic and topographic variables. Three populations (forty-five individuals) from pine-oak and cloud forests located in the Southern Sierra of Oaxaca were analyzed using ten microsatellite loci. The analysis was conducted using Arlequin v. 3.5, Mega v. 10, and Structure v. 2.3 programs. Eight loci were polymorphic, and a total of thirty-eight alleles were obtained. The average number of alleles per polymorphic locus was 4.6. The average heterozygosity of the three populations was high (Ho = 0.5483), and genetic differentiation between populations were low, with a high genetic flow, suggesting that it could be an ancestral population that became fragmented and was just beginning to differentiate genetically. The information generated on this restricted distribution species can be used in conservation programs pertaining to human activities that endanger the habitats where it is found.

Evolutionary insights and brief review of Loxodes Ehrenberg, 1830 (Ciliophora, Karyorelictea, Loxodidae) with description of a new species from Mexico.

Karyorelictids are a group of ciliates inhabiting marine and freshwater biotopes and possessing a non-dividing macronucleus. We describe a new freshwater species based on morphology and the 18S rRNA gene sequence data. Loxodes tziscaensis n. sp. can be easily distinguished from other Loxodes species by the arrangement of the nuclear apparatus and features of the buccal and somatic ciliature. The current proposed 18S rRNA phylogeny of Loxodes, including seven Loxodes species, shows two morphologically well-supported groups. Group A (L. rostrum, type species; L. vorax and L. tziscaensis n. sp.) includes species with a single nuclear group (two macronuclei and one micronucleus), in contrast to species of group B, which possess more than one nuclear group (L. striatus, L. magnus, L. kahli, L. penardi, and L. rex). We propose that the last common ancestor of Loxodes was a marine Remanella-like species possessing a single nuclear group. The division and differentiation of the micronucleus into a new macronucleus and the retention of the old macronuclei, independently of cell division, may have been two crucial processes during the evolution and diversification of Loxodes species with one nuclear group into species with multiple nuclear groups.

Detección y genotipificación de Pneumocystis jirovecii en muestras de pacientes mexicanos VIH positivos y negativos.

INTRODUCTION: Pneumocystis jirovecii is an atypical fungus particularly detected in HIV-positive or transplant patients. OBJECTIVE: To detect and genotype Pneumocystis jirovecii in patient samples from two hospitals in Mexico City. METHOD: Eighty-nine respiratory tract samples, corresponding to 53 patients (30 HIV-positive and 23 HIV-negative) with respiratory symptoms and to 11 healthy individuals included as negative control, were processed. DNA was extracted from the ITS region and amplified by nested polymerase chain reaction from the internal transcribed spacer, with one fragment being obtained at each round (693 and 550 bp). Genotypes and their phylogenetic relationship were determined by sequencing the 550 bp fragment. RESULTS: Forty-eight samples from 30 HIV-positive patients were received from a single hospital, out of which 11 (36.6 %) were positive for Pneumocystis jirovecii. No sample was positive in HIV-negative patients or healthy subjects. The most frequently detected haplotypes were Eg and Em. CONCLUSIONS: The frequency of Pneumocystis jirovecii infection was high in the studied Mexican population. The most common genotype was different from those reported in other countries. It is necessary to address this health problem through early detection of this infection.

INTRODUCCIÓN: Pneumocystis jirovecii es un hongo atípico detectado particularmente en pacientes VIH-positivos o con trasplante. OBJETIVO: Detectar y genotipificar Pneumocystis jirovecii en muestras de pacientes de dos hospitales de la ciudad de México. MÉTODO: Fueron procesadas 89 muestras respiratorias, correspondientes a 53 pacientes (30 VIH positivos y 23 VIH negativos) con sintomatología respiratoria y 11 personas sanas incluidas como control negativo. El DNA fue extraído y amplificado por PCR anidada de la región del espaciador transcrito interno, obteniendo un fragmento en cada ronda (de 693 y 550 pb). Los genotipos y su relación filogenética fueron determinados por secuenciación del fragmento de 550 pb. RESULTADOS: Cuarenta y ocho muestras de 30 pacientes VIH-positivos provenían de un solo hospital, de las cuales 11 (36.6 %) fueron positivas a Pneumocystis jirovecii. Ninguna fue positiva en pacientes VIH-negativos o personas sanas. Los haplotipos detectados con mayor frecuencia fueron Eg y Em. CONCLUSIONES: La frecuencia de infección por Pneumocystis jirovecii fue alta en la población mexicana estudiada. El genotipo más frecuente fue diferente a los reportados en otros países. Es necesario encauzar este problema de salud hacia la detección temprana de esta infección.

Detección y genotipificación de Pneumocystis jirovecii en muestras de pacientes mexicanos VIH positivos y negativos / Detection and genotyping of Pneumocystis jirovecii in samples from HIV positive and negative Mexican patients

Resumen Introducción: Pneumocystis jirovecii es un hongo atípico detectado particularmente en pacientes VIH-positivos o con trasplante. Objetivo: Detectar y genotipificar Pneumocystis jirovecii en muestras de pacientes de dos hospitales de la ciudad de México. Método: Fueron procesadas 89 muestras respiratorias, correspondientes a 53 pacientes (30 VIH positivos y 23 VIH negativos) con sintomatología respiratoria y 11 personas sanas incluidas como control negativo. El DNA fue extraído y amplificado por PCR anidada de la región del espaciador transcrito interno, obteniendo un fragmento en cada ronda (de 693 y 550 pb). Los genotipos y su relación filogenética fueron determinados por secuenciación del fragmento de 550 pb. Resultados: Cuarenta y ocho muestras de 30 pacientes VIH-positivos provenían de un solo hospital, de las cuales 11 (36.6 %) fueron positivas a Pneumocystis jirovecii. Ninguna fue positiva en pacientes VIH-negativos o personas sanas. Los haplotipos detectados con mayor frecuencia fueron Eg y Em. Conclusiones: La frecuencia de infección por Pneumocystis jirovecii fue alta en la población mexicana estudiada. El genotipo más frecuente fue diferente a los reportados en otros países. Es necesario encauzar este problema de salud hacia la detección temprana de esta infección.

Abstract Introduction: Pneumocystis jirovecii is an atypical fungus particularly detected in HIV-positive or transplant patients. Objective: To detect and genotype Pneumocystis jirovecii in patient samples from two hospitals in Mexico City. Method: Eighty-nine respiratory tract samples, corresponding to 53 patients (30 HIV-positive and 23 HIV-negative) with respiratory symptoms and to 11 healthy individuals included as negative control, were processed. DNA was extracted from the ITS region and amplified by nested polymerase chain reaction from the internal transcribed spacer, with one fragment being obtained at each round (693 and 550 bp). Genotypes and their phylogenetic relationship were determined by sequencing the 550 bp fragment. Results: Forty-eight samples from 30 HIV-positive patients were received from a single hospital, out of which 11 (36.6 %) were positive for Pneumocystis jirovecii. No sample was positive in HIV-negative patients or healthy subjects. The most frequently detected haplotypes were Eg and Em. Conclusions: The frequency of Pneumocystis jirovecii infection was high in the studied Mexican population. The most common genotype was different from those reported in other countries. It is necessary to address this health problem through early detection of this infection.

Genetic diversity and demography of the critically endangered Roberts' false brook salamander (Pseudoeurycea robertsi) in Central Mexico.

Land use changes are threatening the maintenance of biodiversity. Genetic diversity is one of the main indicators of biological diversity and is highly important as it shapes the capability of populations to respond to environmental changes. We studied eleven populations of Pseudoeurycea robertsi, a micro-endemic and critically endangered species from the Nevado de Toluca Volcano, a mountain that is part of the Trans-Mexican Volcanic Belt, Mexico. We sequenced the mitochondrial cytochrome b gene from 71 individuals and genotyped 9 microsatellites from 150 individuals. Our results based on the cytochrome b showed two divergent lineages, with moderate levels of genetic diversity and a recently historical demographic expansion. Microsatellite-based results indicated low levels of heterozygosity for all populations and few alleles per locus, as compared with other mole salamander species. We identified two genetically differentiated subpopulations with a significant level of genetic structure. These results provide fundamental data for the development of management plans and conservation efforts for this critically endangered species.

Effects of Phyllophaga (phytallus) hoegei larval density (coleoptera: melolonthidae) on plant and herbivore growth

La herbivoría subterránea ha recibido poca atención. La respuesta de las plantas a la herbivoría subterránea es variable y mediada parcialmente por la identidad y densidad del rizófago. En este estudio se evaluaron 1) los efectos de la herbivoría subterránea de dos densidades de Phyllophaga (Phytalus) hoegei en la biomasa de la planta y el contenido de nitrógeno de tallos y raíces del pasto nativo dominante Muhlenbergia quadridentata, y 2) los efectos de esas dos densidades de larvas en la supervivencia y crecimiento de esta especie. El experimento se llevó a cabo en un área de bosque de pino a 3200msnm. Las plantas se establecieron en macetas en el campo y estuvieron sujetas a herbivoría subterránea (tres niveles) en un diseño completamente al azar con diez repeticiones por tratamiento. Altas densidades del rizófago disminuyeron significativamente la biomasa de raíces y la proporción raíz/tallo, pero no varió la concentración de nitrógeno en los tejidos de las plantas. La sobrevivencia de las larvas de Phyllophaga hoegei no fue afectada por la densidad a la que crecieron, pero en altas densidades, la larva rizófaga disminuyó su tasa de crecimiento relativa y la ganancia de peso.