Yeast diversity in open agave fermentations across Mexico.

Yeasts are a diverse group of fungal microorganisms that are widely used to produce fermented foods and beverages. In Mexico, open fermentations are used to obtain spirits from agave plants. Despite the prevalence of this traditional practice throughout the country, yeasts have only been isolated and studied from a limited number of distilleries. To systematically describe the diversity of yeast species from open agave fermentations, here we generate the YMX-1.0 culture collection by isolating 4524 strains from 68 sites with diverse climatic, geographical, and biological contexts. We used MALDI-TOF mass spectrometry for taxonomic classification and validated a subset of the strains by ITS and D1/D2 sequencing, which also revealed two potential novel species of Saccharomycetales. Overall, the composition of yeast communities was weakly associated with local variables and types of climate, yet a core set of six species was consistently isolated from most producing regions. To explore the intraspecific variation of the yeasts from agave fermentations, we sequenced the genomes of four isolates of the nonconventional yeast Kazachstania humilis. The genomes of these four strains were substantially distinct from a European isolate of the same species, suggesting that they may belong to different populations. Our work contributes to the understanding and conservation of an open fermentation system of great cultural and economic importance, providing a valuable resource to study the biology and genetic diversity of microorganisms living at the interface of natural and human-associated environments.

Responsabilidad profesional derivada del ejercicio de la odontología en Costa Rica: I Parte / Professional responsibility derived from the practice of dentistry in Costa Rica: Part I

El aumento a nivel mundial de las denuncias por responsabilidad profesional en Ciencias de la Salud hace imprescindible que quienes ejerzan esta profesión deban conocer las implicaciones de su labor, así como cumplir con los principios bioéticos y jurídicos para garantizar una sana relación odontólogo-paciente. Es importante comprender que el ejercicio de la odontología en Costa Rica está regulado por normas, códigos y leyes como cualquier otra actividad humana en un Estado de Derecho.

The number of complaints related to professional liability in health sciences has increased worldwide, it is essential for dental professionals to be aware of the implications of their labor, as well as to comply with bioethical and legal principles to ensure a healthy dentist-patient relationship. It is important to understand that the practice of dentistry in Costa Rica is regulated by norms, codes, and laws like any other human activity in a State governed by the rule of law.

Draft Genome Sequence of a Kazachstania humilis Strain Isolated from Agave Fermentation.

The ascomycetous yeast Kazachstania humilis is an active species in backslopped sourdough and in the spontaneous fermentation of several traditional foods and beverages. Here, we report the draft genome sequence of a K. humilis strain isolated from agave must from a traditional distillery in Mexico.

Análisis de huellas labiales en una muestra de estudiantes de odontología de la Universidad de Costa Rica mediante la clasificación de Renaud: estudio piloto / Lip prints analysis in a sample of dentistry students of the University of Costa Rica based in Renaud's classification: pilot study

Resumen El presente estudio, tuvo como objetivo, analizar los distintos patrones morfológicos presentes en las huellas labiales de una determinada población costarricense y su correlación con las variables, sexo, edad y afinidad biológica. Se analizaron 105 huellas labiales pertenecientes a estudiantes de quinto y sexto año de la carrera de odontología de la Universidad de Costa Rica durante el II semestre del 2016. De las 105 huellas labiales analizadas mediante el método de Renaud, el patrón más prevalente fue el tipo C de manera general, mientras que, de manera individual, en labio superior predomina el patrón tipo A y en labio inferior predomina el patrón tipo C. De la totalidad de muestras analizadas, se destaca que todas revelaron patrones distintos y la correlación estadística entre las variables, sexo, edad y afinidad biológica, permitió conocer la existencia de elementos que podrían ser útiles para identificación de individuos en el ámbito forense. Los resultados demuestran que, con la aplicación de las técnicas adecuadas en la toma de muestras y un análisis estandarizado, las huellas labiales pueden ser utilizadas en el ámbito forense como método de identificación de individuos. Este estudio, además, pone en evidencia la necesidad de realizar más investigación sobre huellas labiales en Costa Rica, no sólo por la necesidad de un aumento en el número de muestras y así obtener mayores resultados estadísticos, si no también, para desarrollar las herramientas necesarias en la toma, revelado y análisis de huellas labiales, así como su aplicabilidad al servicio de la justicia costarricense.

Abstract The objective of this study was to analyze the different morphological patterns present in the lip prints of a certain Costa Rican population and its correlation with the variables, sex, age and biological affinity. 105 lip prints were analyzed belonging to fifth and sixth year students of the dental career of the University of Costa Rica during the second semester of 2016. Of the 105 labials analyzed by the Renaud method, the most prevalent pattern was type C in general, while, individually, in the upper lip, predominantly, the type of pattern, A and the lower lip, predominantly the type C pattern. Of the total of the analyzed samples, the different patterns and the statistical correlation between the variables, sex, age and biological affinity, remarks information that can be useful to identify individuals in the forensic field. The results show that, with the application of the appropriate techniques in the taking of samples and a standardized analysis, the lip prints can be used in the field of forensic science as a method of identification of individuals. This study also highlights the need to conduct more research on lip prints in Costa Rica, not only to increase the number of samples, but also to obtain more extended statistical results. Besides, this research can be used to develop the necessary tools in the taking, development and analysis of lip print. Moreover, the results obtained may be taken into consideration in order to improve forensic research in the Costa Rican justice system.

Successful isolation of Leishmania infantum from Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) collected from naturally infected dogs.

BACKGROUND: The main transmission route of Leishmania infantum is through the bites of sand flies. However, alternative mechanisms are being investigated, such as through the bites of ticks, which could have epidemiological relevance. The objective of this work was to verify the presence of Leishmania spp. in Rhipicephalus sanguineus sensu lato collected from naturally infected dogs in the Federal District of Brazil. METHODS: Ticks were dissected to remove their intestines and salivary glands for DNA extraction and the subsequent amplification of the conserved region of 120 bp of kDNA and 234 bp of the hsp70 gene of Leishmania spp. The amplified kDNA products were digested with endonucleases HaeIII and BstUI and were submitted to DNA sequencing. Isolated Leishmania parasites from these ticks were analyzed by multilocus enzyme electrophoresis, and the DNA obtained from this culture was subjected to microsatellite analyses. RESULTS: Overall, 130 specimens of R. sanguineus were collected from 27 dogs. Leishmania spp. were successfully isolated in culture from five pools of salivary glands and the intestines of ticks collected from four dogs. The amplified kDNA products from the dog blood samples and from the tick cultures, when digested by HaeIII and BstUI, revealed the presence of L. braziliensis and L. infantum. One strain was cultivated and characterized as L. infantum by enzyme electrophoresis. The amplified kDNA products from the blood of one dog showed a sequence homology with L. braziliensis; however, the amplified kDNA from the ticks collected from this dog showed a sequence homology to L. infantum. CONCLUSION: The results confirm that the specimens of R. sanguineus that feed on dogs naturally infected by L. infantum contain the parasite DNA in their intestines and salivary glands, and viable L. infantum can be successfully isolated from these ectoparasites.

DNA diversification in two Sinorhizobium species.

The comparative analysis of genomic characteristics and single-nucleotide polymorphism patterns from large fragments borne on different replicons of Sinorhizobium spp. genomes clearly demonstrate that DNA recombination among closely related bacteria is a major event in the diversification of this genome, especially in pSymA, resulting in mosaic structure.

Recurrent DNA inversion rearrangements in the human genome.

Several lines of evidence suggest that reiterated sequences in the human genome are targets for nonallelic homologous recombination (NAHR), which facilitates genomic rearrangements. We have used a PCR-based approach to identify breakpoint regions of rearranged structures in the human genome. In particular, we have identified intrachromosomal identical repeats that are located in reverse orientation, which may lead to chromosomal inversions. A bioinformatic workflow pathway to select appropriate regions for analysis was developed. Three such regions overlapping with known human genes, located on chromosomes 3, 15, and 19, were analyzed. The relative proportion of wild-type to rearranged structures was determined in DNA samples from blood obtained from different, unrelated individuals. The results obtained indicate that recurrent genomic rearrangements occur at relatively high frequency in somatic cells. Interestingly, the rearrangements studied were significantly more abundant in adults than in newborn individuals, suggesting that such DNA rearrangements might start to appear during embryogenesis or fetal life and continue to accumulate after birth. The relevance of our results in regard to human genomic variation is discussed.

Post-ischemic administration of progesterone in rats exerts neuroprotective effects on the hippocampus.

Progesterone is neuroprotective in models of focal or global ischemia when treatment starts either before the insult or at the onset of reperfusion. In these cases the steroid may act during the occurrence of the early pathophysiological events triggered by ischemia or reperfusion. As opposed to this condition, the aim of the present study was to assess the effect of delayed, post-injury administration of progesterone on the preservation of pyramidal neurons of the hippocampus of rats 21 days after been exposed to global ischemia by the four vessel occlusion model. Progesterone (8 mg/kg, i.v.) or its vehicle, were administered at 20 min, 2, 6, and 24h after the end of ischemia. At histological examination, brains of the ischemic vehicle-treated rats showed a severe reduction of the population of pyramidal neurons in the CA1 and CA2 subfields (12% and 29% remaining neurons, respectively), and a less severe neuronal loss in the CA3 and CA4 subfields of the hippocampus (68% and 63% remaining neurons, respectively), as compared to rats exposed to sham procedures. They also showed a two-fold enlargement of the lateral ventricles and 33% shrinkage of the cerebral cortex as compared to the sham group. Progesterone treatment resulted in a significant preservation of pyramidal neurons in CA1 and CA2 (40% and 62% remaining neurons), with no ventricular dilation and only a mild (12%) cortical shrinkage. Results suggest that progesterone is able to interfere with some late pathophysiological mechanisms leading both to selective neuronal damage in the hippocampal CA1 and CA2 subfields, and to shrinkage of the cerebral cortex.