First report of Cassava Bacterial Blight caused by Xanthomonas phaseoli pv. manihotis in the Amazonian forest of Ecuador.

Xanthomonas phaseoli pv. manihotis (Xpm) is a plant pathogenic bacterium known as the causal agent of cassava bacterial blight (CBB). CBB is the most limiting bacterial disease affecting cassava (Manihot esculenta Crantz), characterized by diverse symptoms including angular water-soaked leaf lesions, blight, wilting, stem exudates, stem cankers and dieback. CBB has been reported in most cassava-growing regions around the world, and, under conducive conditions, crop yield losses can reach up to 100% (Zárate-Chaves et al. 2021). While Xpm genetic diversity is remarkably high in South America (Bart et al. 2012) and cassava originates and was domesticated in the Amazon basin (Allem 2002), reports of CBB in the Amazonian region are missing. To fill this gap, in October 2018 we surveyed for CBB symptoms in cassava fields of the Orellana Province, located in the Amazon forest of the Republic of Ecuador. Adult cassava plants exhibiting typical angular, water-soaked leaf lesions were found in polyculture plots, i.e. intercrops of cassava with other species such as plantains and fruit trees (a.k.a. chakras). After surface disinfection with 5% sodium hypochlorite followed by 70% ethanol, white Xpm-like colonies were isolated from diseased leaf tissues of four plants on YPGA medium (yeast extract, 5 g/l; peptone, 5 g/l; glucose, 5 g/l; agar-agar, 15 g/l) supplemented with cephalexin (40 mg/l) and cycloheximide (50 mg/l). Pathogenicity tests were performed on peat-potted, 2-month-old cassava plants of the cultivar 60444. Bacterial suspensions were adjusted to an OD600 of 0.2 (2 × 108 CFU/ml) in sterile 10-mM MgCl2 and syringe infiltrated in fully-expanded leaves. In parallel, 20 µl of each bacterial suspension adjusted to an OD600 of 0.02 (2 × 107 CFU/ml) were inoculated on stems inside a hole previously punched with a sterile needle in the junction of the third-top petiole. Sterile 10-mM MgCl2 was used for mock inoculations in both leaves and stems, and experiments were replicated in three plants. Plants were incubated in a greenhouse at 28 ± 1°C with a 12-h photoperiod. Infiltrated leaves developed watersoaking 3 days post inoculation, while wilted leaves, stem exudates, and dieback were observed 21 days after stem inoculation. Control plants remained symptomless. White Xpm-like colonies were re-isolated from symptomatic leaves (Fig S1). One colony of each of the four Xpm isolates (before and after re-isolation) was assessed using diagnostic PCRs (Bernal-Galeano et al. 2018; Flores et al. 2019), using strain Xam668 as positive control. All four candidates were positive for both diagnostic tools. The sequences of the housekeeping genes atpD, dnaK, efp, glnA, gyrB and rpoD of our isolates were extracted from full genome sequences obtained through Oxford Nanopore Technologies (ONT) (GenBank OR288194 to OR288217) and compared to their homologs in four close Xanthomonas species and a reference Xpm strain (Table S1). The sequences of the tested strains aligned with that of Xpm CIO151 (GCA_004025275.1) (Arrieta-Ortiz et al. 2013) with nucleotide identity above 99.92% (Fig S2). The four strains were named CIX4169, CIX4170, CIX4171 and CIX4172, stored in the IRD Collection of Xanthomonas, where they are available upon request. To our knowledge, this is the first report of CBB in the Amazonian region and in Ecuador, where cassava is a central element for local culture and economy. Further surveys will be necessary to evaluate the distribution and prevalence of CBB in other ecozones of Ecuador where cassava is cultivated.

Rabbit Fibroma Virus infection in domestic rabbits (Oryctolagus cuniculus) in Mexico.

Rabbit Fibroma is a Leporipoxviral disease and is considered the third most common cutaneous neoplasm in pet rabbits. Two domestic rabbits (Oryctolagus cuniculus) were submitted to the veterinary clinic due to the presence of a nodule on the lip. Histologically, epithelial cells of the epidermis and hair follicles showed mild to moderate ballooning degeneration, spongiosis, and several eosinophilic intracytoplasmic inclusion bodies. The dermis was expanded by atypical spindle cells that also showed eosinophilic intracytoplasmic inclusion bodies. The tissues were evaluated by using transmission electron microscopy. In both cases, keratinocytes exhibit several electron dense and pleomorphic intracytoplasmic viral particles consistent with Poxviruses. To our knowledge, this is the first case report of Rabbit Fibroma Virus infection in Domestic Rabbits in Mexico.

Changes in the levels of free sialic acid during ex vivo lung perfusion do not correlate with pulmonary function. Experimental model.

BACKGROUND: Ex vivo lung perfusion (EVLP) constitutes a tool with great research potential due to its advantages over in vivo and in vitro models. Despite its important contribution to lung reconditioning, this technique has the disadvantage of incurring high costs and can induce pulmonary endothelial injury through perfusion and ventilation. The pulmonary endothelium is made up of endothelial glycocalyx (EG), a coating of proteoglycans (PG) on the luminal surface. PGs are glycoproteins linked to terminal sialic acids (Sia) that can affect homeostasis with responses leading to edema formation. This study evaluated the effect of two ex vivo perfusion solutions on lung function and endothelial injury. METHODS: We divided ten landrace swine into two groups and subjected them to EVLP for 120 min: Group I (n = 5) was perfused with Steen® solution, and Group II (n = 5) was perfused with low-potassium dextran-albumin solution. Ventilatory mechanics, histology, gravimetry, and sialic acid concentrations were evaluated. RESULTS: Both groups showed changes in pulmonary vascular resistance and ventilatory mechanics (p < 0.05, Student's t-test). In addition, the lung injury severity score was better in Group I than in Group II (p < 0.05, Mann-Whitney U); and both groups exhibited a significant increase in Sia concentrations in the perfusate (p < 0.05 t-Student) and Sia immunohistochemical expression. CONCLUSIONS: Sia, as a product of EG disruption during EVLP, was found in all samples obtained in the system; however, the changes in its concentration showed no apparent correlation with lung function.

A minisatellite-based MLVA for deciphering the global epidemiology of the bacterial cassava pathogen Xanthomonas phaseoli pv. manihotis.

Cassava Bacterial Blight (CBB) is a destructive disease widely distributed in the different areas where this crop is grown. Populations studies have been performed at local and national scales revealing a geographical genetic structure with temporal variations. A global epidemiology analysis of its causal agent Xanthomonas phaseoli pv. manihotis (Xpm) is needed to better understand the expansion of the disease for improving the monitoring of CBB. We targeted new tandem repeat (TR) loci with large repeat units, i.e. minisatellites, that we multiplexed in a scheme of Multi-Locus Variable number of TR Analysis (MLVA-8). This genotyping scheme separated 31 multilocus haplotypes in three clusters of single-locus variants and a singleton within a worldwide collection of 93 Xpm strains isolated over a period of fifty years. The major MLVA-8 cluster 1 grouped strains originating from all countries, except the unique Chinese strain. On the contrary, all the Xpm strains genotyped using the previously developed MLVA-14 microsatellite scheme were separated as unique haplotypes. We further propose an MLVA-12 scheme which takes advantage of combining TR loci with different mutation rates: the eight minisatellites and four faster evolving microsatellite markers, for global epidemiological surveillance. This MLVA-12 scheme identified 78 haplotypes and separated most of the strains in groups of double-locus variants (DLV) supporting some phylogenetic relationships. DLV groups were subdivided into closely related clusters of strains most often sharing the same geographical origin and isolated over a short period, supporting epidemiological relationships. The main MLVA-12 DLV group#1 was composed by strains from South America and all the African strains. The MLVA-12 scheme combining both minisatellite and microsatellite loci with different discriminatory power is expected to increase the accuracy of the phylogenetic signal and to minimize the homoplasy effects. Further investigation of the global epidemiology of Xpm will be helpful for a better control of CBB worldwide.

Sindrome de Goldenhar asociado con un dermoide epibulbar: Reporte de Caso / Goldenhar syndrome associated with an epibulbar dermoid: Case Report

Presentamos el caso de un escolar varón de 7 años con Sindrome de Goldenhar asociado a un coristoma epibulbar. El paciente presenta una tumoración homogénea, de forma redondeada, con bordes bien delimitados, de consistencia blanda, vascularizada, de aproximadamente 9x10 mm, de color blanco­amarillento, adherido a esclera y córnea, con formaciones pilosas en su superficie, ubicada a nivel del limbo esclerocorneal del cuadrante temporal-inferior del ojo derecho. El estudio histopatológico demostró la presencia de folículos pilosos y glándulas sebáceas, inmersas en un estroma de tejido conectivo fibroso con un revestimiento superficial de tipo escamoso, lo cual definió el diagnóstico de dermoide epibulbar limbar. Se realiza conjuntivoplastía para recubrir el defecto escleral y se usa membrana amniótica para recubrir el defecto corneal y escleral. El dermoide epibulbar limbar es el tipo más común de coristoma conjuntival y debe ser considerado en el diagnóstico diferencial de los tumores epibulbares pediátricos.

We present the case of a 7-year-old male child with Goldenhar syndrome associated with an epibulbar choristoma. The patient presents a homogeneous tumor, rounded in shape, with well-defined borders, of a soft consistency, vascularized, approximately 9x10 mm, yellowish-white in color, adhered to the sclera and cornea, with hairy formations on its surface, located at the level of the sclerocorneal limbus of the temporal-lower quadrant of his right eye. The histopathology study showed the presence of hair follicles and sebaceous glands, immersed in a stroma of fibrous connective tissue with a superficial squamous-type lining, which defined the diagnosis of limbar epibulbar dermoid. Conjunctivaplasty was performed to cover the scleral defect and use amniotic membrane to cover the corneal and scleral defect. The limbar epibulbar dermoid is the most common type of conjunctival choristoma and should be considered in the differential diagnosis of pediatric epibulbar tumors.

Comprehensive Time-Series Analysis of the Gene Expression Profile in a Susceptible Cultivar of Tree Tomato (Solanum betaceum) During the Infection of Phytophthora betacei.

Solanum betaceum is a tree from the Andean region bearing edible fruits, considered an exotic export. Although there has been renewed interest in its commercialization, sustainability, and disease management have been limiting factors. Phytophthora betacei is a recently described species that causes late blight in S. betaceum. There is no general study of the response of S. betaceum, particularly, in the changes in expression of pathogenesis-related genes. In this manuscript we present a comprehensive RNA-seq time-series study of the plant response to the infection of P. betacei. Following six time points of infection, the differentially expressed genes (DEGs) involved in the defense by the plant were contextualized in a sequential manner. We documented 5,628 DEGs across all time-points. From 6 to 24 h post-inoculation, we highlighted DEGs involved in the recognition of the pathogen by the likely activation of pattern-triggered immunity (PTI) genes. We also describe the possible effect of the pathogen effectors in the host during the effector-triggered response. Finally, we reveal genes related to the susceptible outcome of the interaction caused by the onset of necrotrophy and the sharp transcriptional changes as a response to the pathogen. This is the first report of the transcriptome of the tree tomato in response to the newly described pathogen P. betacei.

A whole genome duplication drives the genome evolution of Phytophthora betacei, a closely related species to Phytophthora infestans.

BACKGROUND: Pathogens of the genus Phytophthora are the etiological agents of many devastating diseases in several high-value crops and forestry species such as potato, tomato, cocoa, and oak, among many others. Phytophthora betacei is a recently described species that causes late blight almost exclusively in tree tomatoes, and it is closely related to Phytophthora infestans that causes the disease in potato crops and other Solanaceae. This study reports the assembly and annotation of the genomes of P. betacei P8084, the first of its species, and P. infestans RC1-10, a Colombian strain from the EC-1 lineage, using long-read SMRT sequencing technology. RESULTS: Our results show that P. betacei has the largest sequenced genome size of the Phytophthora genus so far with 270 Mb. A moderate transposable element invasion and a whole genome duplication likely explain its genome size expansion when compared to P. infestans, whereas P. infestans RC1-10 has expanded its genome under the activity of transposable elements. The high diversity and abundance (in terms of copy number) of classified and unclassified transposable elements in P. infestans RC1-10 relative to P. betacei bears testimony of the power of long-read technologies to discover novel repetitive elements in the genomes of organisms. Our data also provides support for the phylogenetic placement of P. betacei as a standalone species and as a sister group of P. infestans. Finally, we found no evidence to support the idea that the genome of P. betacei P8084 follows the same gene-dense/gense-sparse architecture proposed for P. infestans and other filamentous plant pathogens. CONCLUSIONS: This study provides the first genome-wide picture of P. betacei and expands the genomic resources available for P. infestans. This is a contribution towards the understanding of the genome biology and evolutionary history of Phytophthora species belonging to the subclade 1c.

Novel Human-Derived RET Fusion NSCLC Cell Lines Have Heterogeneous Responses to RET Inhibitors and Differential Regulation of Downstream Signaling.

Rearranged during transfection (RET) rearrangements occur in 1% to 2% of lung adenocarcinomas as well as other malignancies and are now established targets for tyrosine kinase inhibitors. We developed three novel RET fusion-positive (RET+) patient-derived cancer cell lines, CUTO22 [kinesin 5B (KIF5B)-RET fusion], CUTO32 (KIF5B-RET fusion), and CUTO42 (echinoderm microtubule-associated protein-like 4-RET fusion), to study RET signaling and response to therapy. We confirmed each of our cell lines expresses the RET fusion protein and assessed their sensitivity to RET inhibitors. We found that the CUTO22 and CUTO42 cell lines were sensitive to multiple RET inhibitors, whereas the CUTO32 cell line was >10-fold more resistant to three RET inhibitors. We discovered that our RET+ cell lines had differential regulation of the mitogen-activated protein kinase and phosphoinositide 3-kinase/protein kinase B (AKT) pathways. After inhibition of RET, the CUTO42 cells had robust inhibition of phosphorylated AKT (pAKT), whereas CUTO22 and CUTO32 cells had sustained AKT activation. Next, we performed a drug screen, which revealed that the CUTO32 cells were sensitive (<1 nM IC50) to inhibition of two cell cycle-regulating proteins, polo-like kinase 1 and Aurora kinase A. Finally, we show that two of these cell lines, CUTO32 and CUTO42, successfully establish xenografted tumors in nude mice. We demonstrated that the RET inhibitor BLU-667 was effective at inhibiting tumor growth in CUTO42 tumors but had a much less profound effect in CUTO32 tumors, consistent with our in vitro experiments. These data highlight the utility of new RET+ models to elucidate differences in response to tyrosine kinase inhibitors and downstream signaling regulation. Our RET+ cell lines effectively recapitulate the interpatient heterogeneity observed in response to RET inhibitors and reveal opportunities for alternative or combination therapies. SIGNIFICANCE STATEMENT: We have derived and characterized three novel rearranged during transfection (RET) fusion non-small cell lung cancer cell lines and demonstrated that they have differential responses to RET inhibition as well as regulation of downstream signaling, an area that has previously been limited by a lack of diverse cell line modes with endogenous RET fusions. These data offer important insight into regulation of response to RET tyrosine kinase inhibitors and other potential therapeutic targets.

Trypanosoma cruzi seroprevalence and associated factors in women in Casanare-Colombia.

Chagas disease is caused by the parasite Trypanosoma cruzi and transmitted mainly by triatomines and from mothers to children. In Colombia, this disease is a public health problem and due to its high endemicity and vertical transmission, women are susceptible populations that must be evaluated. Our objective was to determinate the Trypanosoma cruzi seroprevalence and factors associated with women in Pore (Municipality), Casanare, Colombia. Cross-sectional study. A sample of 230 healthy volunteer women, 15 years or older, without previous diagnosis of Chagas disease was taken; the serological analysis was done using the Chagas ELISA IgG and IgM and indirect Hemagglutination (HAI) technique. In addition, a survey was applied to each participant in order to explore the presence of factors that could be associated with a positive test result. The seropostitivity found in Pore Casanare's women was 16.9% (39/230, 95% CI 12.1-21.7), additionally it was found that rural origin, the coexistence with animals, especially chickens, age, low level schooling and housing material are factors associated with T. cruzi infection in this population. The results of this study indicate the importance of conducting extensive seroepidemiological studies in populations of endemic areas, due to the difficulty in detecting cases in the acute phase; therefore, screening allows the establishment of a follow-up and treatment time line that contributes to the interruption of the transmission vertical.

The type VI secretion system of Xanthomonas phaseoli pv. manihotis is involved in virulence and in vitro motility.

BACKGROUND: The type VI protein secretion system (T6SS) is important in diverse cellular processes in Gram-negative bacteria, including interactions with other bacteria and with eukaryotic hosts. In this study we analyze the evolution of the T6SS in the genus Xanthomonas and evaluate its importance of the T6SS for virulence and in vitro motility in Xanthomonas phaseoli pv. manihotis (Xpm), the causal agent of bacterial blight in cassava (Manihot esculenta). We delineate the organization of the T6SS gene clusters in Xanthomonas and then characterize proteins of this secretion system in Xpm strain CIO151. RESULTS: We describe the presence of three different clusters in the genus Xanthomonas that vary in their organization and degree of synteny between species. Using a gene knockout strategy, we also found that vgrG and hcp are required for maximal aggressiveness of Xpm on cassava plants while clpV is important for both motility and maximal aggressiveness. CONCLUSION: We characterized the T6SS in 15 different strains in Xanthomonas and our phylogenetic analyses suggest that the T6SS might have been acquired by a very ancient event of horizontal gene transfer and maintained through evolution, hinting at their importance for the adaptation of Xanthomonas to their hosts. Finally, we demonstrated that the T6SS of Xpm is functional, and significantly contributes to virulence and motility. This is the first experimental study that demonstrates the role of the T6SS in the Xpm-cassava interaction and the T6SS organization in the genus Xanthomonas.

Top-Down Enrichment Strategy to Co-cultivate Lactic Acid and Lignocellulolytic Bacteria From the Megathyrsus maximus Phyllosphere.

Traditionally, starting inoculants have been applied to improve ensiling of forage used for livestock feed. Here, we aimed to build up a bioinoculant composed of lactic acid-producing and lignocellulolytic bacteria (LB) derived from the Megathyrsus maximus (guinea grass) phyllosphere. For this, the dilution-to-stimulation approach was used, including a sequential modification of the starting culture medium [Man, Rogosa, and Sharpe (MRS) broth] by addition of plant biomass (PB) and elimination of labile carbon sources. Along 10 growth-dilution steps (T1-T10), slight differences were observed in terms of bacterial diversity and composition. After the sixth subculture, the consortium started to degrade PB, decreasing its growth rate. The co-existence of Enterobacteriales (fast growers and highly abundance), Actinomycetales, Bacillales, and Lactobacillales species was observed at the end of the selection process. However, a significant structural change was noticed when the mixed consortium was cultivated in higher volume (500ml) for 8days, mainly increasing the proportion of Paenibacillaceae populations. Interestingly, Actinomycetales, Bacillales, and Lactobacillales respond positively to a pH decrease (4-5), suggesting a relevant role within a further silage process. Moreover, gene-centric metagenomic analysis showed an increase of (hemi)cellulose-degrading enzymes (HDEs) during the enrichment strategy. Reconstruction of metagenome-assembled genomes (MAGs) revealed that Paenibacillus, Cellulosimicrobium, and Sphingomonas appear as key (hemi)cellulolytic members (harboring endo-glucanases/xylanases, arabinofuranosidases, and esterases), whereas Enterococcus and Cellulosimicrobium have the potential to degrade oligosaccharides, metabolize xylose and might produce lactic acid through the phosphoketolase (PK) pathway. Based on this evidence, we conclude that our innovative top-down strategy enriched a unique bacterial consortium that could be useful in biotechnological applications, including the development/design of a synthetic bioinoculant to improve silage processes.

Leishmania mexicana: Novel Insights of Immune Modulation through Amastigote Exosomes.

Exosomes are extracellular microvesicles of endosomal origin (multivesicular bodies, MVBs) constitutively released by eukaryotic cells by fusion of MVBs to the plasma membrane. The exosomes from Leishmania parasites contain an array of parasite molecules such as virulence factors and survival messengers, capable of modulating the host immune response and thereby favoring the infection of the host. We here show that exosomes of L. mexicana amastigotes (aExo) contain the virulence proteins gp63 and PP2C. The incubation of aExo with bone marrow-derived macrophages (BMMs) infected with L. mexicana led to their internalization and were found to colocalize with the cellular tetraspanin CD63. Furthermore, aExo inhibited nitric oxide production of infected BMMs, permitting enhanced intracellular parasite survival. Expressions of antigen-presenting (major histocompatibility complex class I, MHC-I, and CD1d) and costimulatory (CD86 and PD-L1) molecules were modulated in a dose-dependent fashion. Whereas MHC-I, CD86 and PD-L1 expressions were diminished by exosomes, CD1d was enhanced. We conclude that aExo of L. mexicana are capable of decreasing microbicidal mechanisms of infected macrophages by inhibiting nitric oxide production, thereby enabling parasite survival. They also hamper the cellular immune response by diminishing MHC-I and CD86 on an important antigen-presenting cell, which potentially interferes with CD8 T cell activation. The enhanced CD1d expression in combination with reduction of PD-L1 on BMMs point to a potential shift of the activation route towards lipid presentations, yet the effectivity of this immune activation is not evident, since in the absence of costimulatory molecules, cellular anergy and tolerance would be expected.

Genome-Scale Metabolic Model of Xanthomonas phaseoli pv. manihotis: An Approach to Elucidate Pathogenicity at the Metabolic Level.

Xanthomonas phaseoli pv. manihotis (Xpm) is the causal agent of cassava bacterial blight, the most important bacterial disease in this crop. There is a paucity of knowledge about the metabolism of Xanthomonas and its relevance in the pathogenic process, with the exception of the elucidation of the xanthan biosynthesis route. Here we report the reconstruction of the genome-scale model of Xpm metabolism and the insights it provides into plant-pathogen interactions. The model, iXpm1556, displayed 1,556 reactions, 1,527 compounds, and 890 genes. Metabolic maps of central amino acid and carbohydrate metabolism, as well as xanthan biosynthesis of Xpm, were reconstructed using Escher (https://escher.github.io/) to guide the curation process and for further analyses. The model was constrained using the RNA-seq data of a mutant of Xpm for quorum sensing (QS), and these data were used to construct context-specific models (CSMs) of the metabolism of the two strains (wild type and QS mutant). The CSMs and flux balance analysis were used to get insights into pathogenicity, xanthan biosynthesis, and QS mechanisms. Between the CSMs, 653 reactions were shared; unique reactions belong to purine, pyrimidine, and amino acid metabolism. Alternative objective functions were used to demonstrate a trade-off between xanthan biosynthesis and growth and the re-allocation of resources in the process of biosynthesis. Important features altered by QS included carbohydrate metabolism, NAD(P)+ balance, and fatty acid elongation. In this work, we modeled the xanthan biosynthesis and the QS process and their impact on the metabolism of the bacterium. This model will be useful for researchers studying host-pathogen interactions and will provide insights into the mechanisms of infection used by this and other Xanthomonas species.

Revisión: Factores asociados a cáncer colorrectal / Review: Associated factors with colorectal cancer

Resumen Introducción: El cáncer colorrectal (CCR) es la neoplasia de mayor frecuencia en vías digestivas, constituyendo del 9 al 10% de todos los cánceres en el mundo. Se considera que es multicausal, pues abarca factores intrínsecos del huésped como mutaciones genéticas, hormonales y condiciones inmunológicas; además de factores externos como dietas poco saludables, consumo de alcohol, obesidad, sedentarismo, tabaquismo y la exposición ambiental a carcinógenos. Las manifestaciones clínicas son poco específicas, razón por la cual el diagnóstico está enfocado en grupos de riesgo relacionados con la edad e historia familiar demostrada. Objetivo: Identificar los factores genéticos y de estilos de vida predisponentes al desarrollo de CCR. Metodología: Se realizó una búsqueda de la bibliografía respectiva en las bases de datos ScienceDirect, Google académico, Redalyc, Scielo, Proquest publicada durante el período 2004- 2019, mediante las palabras clave: Colorrectal cancer, risk factors, epidemiology, mortality, mutation, incidence. Resultados: Se observaron factores genéticos predisponentes entre un 20% a 25% de las personas con CCR asociados principalmente con la mutación de gen APC. En relación al cáncer esporádico, se identifica hasta en un 80% de los casos, relacionado con el consumo no controlado de alimentos como carnes rojas, embutidos, café, además de hábitos como el consumo de cigarrillo y alcohol conjuntamente con el estrés y comorbilidades como la obesidad y la diabetes. Conclusión: La multicausalidad del CCR está centrada en factores tanto internos como externos siendo de relevancia el seguimiento para personas genéticamente predispuestas y la implementación de estilos de vida saludables que reduzcan la mortalidad por esta causa.

Abstract Introduction: Colorectal cancer (CRC) is the most frequent neoplasm in the digestive tract; it constitutes 9 of 10% of all cancer cases in the world. This type of cancer is considered multicausal since it is associated with intrinsic and extrinsic factors. Among the internal factors, there are genetic, hormonal mutations, and immunological conditions. On the other hand, the external factors are composed of unhealthy diets, alcohol consumption, obesity, sedentary lifestyle, smoking habits, and environmental exposure to carcinogens. The clinical symptoms are not very specific; that is why the diagnosis is focused on risk groups related to age and proven family medical history. Objective: To identify genetic factors and lifestyle factors related to the development of Colorectal cancer (CRC). Methodology: A literature search was carried out in databases such as ScienceDirect, Google Scholar, Redalyc, Scielo, Proquest, in a range of time between 2004 and 2019. The keywords: colorectal cancer, risk factors, epidemiology, mortality, mutation, and incidence were used as helpers for the search. Results: Predisposing genetic factors were observed in about 20% to 25% of people with CRC associated primarily with the APC gene mutation. In terms of sporadic cancer, the results showed that 80% of the cases were related to the uncontrolled consumption of red meat, sausages, and coffee. Additionally, smoking and alcoholic behaviors, stress, and comorbidities, such as obesity and diabetes, were also the cause of the development of this issue. Conclusion: CRC could be caused by internal and external factors. Based on this, the people with a genetic predisposition to this issue should monitor themselves frequently and implement a healthy lifestyle that reduces the probability of suffering from this type of cancer.

Hepatogenous photosensitization by Brachiaria spp. in sheep: first report in Mexico

Ruminants are highly susceptible to photosensitization caused by the ingestion of hepatotoxic plants. In two adjacent farms in Colima, Mexico, several sheep exhibited signs of depression and crusting dermatitis involving the ears, periorbital skin, eyelids, nostrils, and axillary regions. Results of serum biochemistry were indicative of liver injury. Post mortem examination revealed jaundice, craniofacial edema as well as an enlarged liver having an orange-brown discoloration; on the cut surface, the hepatic parenchyma had a subtle zonal pattern. Histopathological findings were those of severe necrotizing dermatitis, lymphoplasmacytic cholangiohepatitis, and renal tubular necrosis. Acicular crystals were microscopically and ultrastructurally evident in hepatocytes, Kupffer cells, biliary ducts, renal tubules and interstitium. The clinical, gross and microscopic findings were consistent with hepatogenous photosensitization. A field investigation revealed that affected sheep had been grazing Brachiaria spp., a potentially toxic grass originated from Africa and commonly cultivated in Australia and South America. This grass contains hepatotoxic saponins that cause liver injury and secondary hepatogenous photosensitization. Although frequently reported in South America, to our knowledge, this is the first report of Brachiaria spp. toxicity in Mexico.

Hepatogenous photosensitization by Brachiaria spp. in sheep: first report in Mexico

Ruminants are highly susceptible to photosensitization caused by the ingestion of hepatotoxic plants. In two adjacent farms in Colima, Mexico, several sheep exhibited signs of depression and crusting dermatitis involving the ears, periorbital skin, eyelids, nostrils, and axillary regions. Results of serum biochemistry were indicative of liver injury. Post mortem examination revealed jaundice, craniofacial edema as well as an enlarged liver having an orange-brown discoloration; on the cut surface, the hepatic parenchyma had a subtle zonal pattern. Histopathological findings were those of severe necrotizing dermatitis, lymphoplasmacytic cholangiohepatitis, and renal tubular necrosis. Acicular crystals were microscopically and ultrastructurally evident in hepatocytes, Kupffer cells, biliary ducts, renal tubules and interstitium. The clinical, gross and microscopic findings were consistent with hepatogenous photosensitization. A field investigation revealed that affected sheep had been grazing Brachiaria spp., a potentially toxic grass originated from Africa and commonly cultivated in Australia and South America. This grass contains hepatotoxic saponins that cause liver injury and secondary hepatogenous photosensitization. Although frequently reported in South America, to our knowledge, this is the first report of Brachiaria spp. toxicity in Mexico.(AU)

Comportamiento epidemiológico de la leptospirosis humana en Colombia, 2012-2016 / Epidemiology of human leptospirosis in Colombia, 2012-2016

Introducción: La leptospirosis en una enfermedad zoonótica, bacteriana de amplia distribución mundial, con impacto socioeconómico desconocido por la falta de estudios epidemiológicos que ofrezcan datos de mortalidad y morbilidad más cercanos a la realidad. Objetivo: Describir el comportamiento de casos de leptospirosis humana notificados al Sivigila en Colombia durante los años 2012 a 2016. Métodos: Estudio observacional descriptivo, mediante el cual se analizaron los registros de los informes anuales de evento de leptospirosis notificados al Sivigila durante los años 2012 al 2016 en Colombia. Para ello se utilizó la hoja de cálculo Excel. Resultados: Durante el quinquenio observado se notificó un total de 10 435 casos de leptospirosis. Según características sociodemográficas el mayor número se presentó en hombres, el 49,8 por ciento pertenecía al régimen subsidiado, la mayoría se presentó en la cabecera municipal y la población más afectada correspondió a sin identificación étnica. Dentro de los antecedentes epidemiológicos más importantes se halló el contacto con caninos, ratas en el domicilio y actividades de río. Conclusiones: La compilación de los datos epidemiológicos de la vigilancia de leptospirosis humana demuestra que sigue siendo un problema de salud pública, lo cual genera preocupación y demanda mejoras en las estrategias nacionales de prevención y control(AU)

Introduction: Leptospirosis is a zoonotic bacterial disease of broad worldwide distribution. Its socioeconomic impact is not known, due to the lack of epidemiological studies providing reliable mortality and morbidity data. Objective: Describe the evolution of cases of human leptospirosis reported to Sivigila in Colombia from 2012 to 2016. Methods: An observational descriptive study was conducted based on the records of annual reports of leptospirosis notified to Sivigila in Colombia from 2012 to 2016. Use was made of Microsoft Excel spreadsheets. Results: A total 10 435 cases of leptospirosis were reported during the five-year period analyzed. Sociodemographic characterization showed that the largest number of cases were men, 49.8 % belonged to the subsidized regime, most occurred in the municipal capital, and the most commonly affected population was the group without ethnic identification. The most relevant epidemiological antecedents were contact with canines, rats in the household and fluvial activities. Conclusions: Gathering of epidemiological data about surveillance of human leptospirosis revealed that this disease continues to be a worrisome public health problem that demands improved national prevention and control strategies(AU)

Anti-Leptospira spp. antibodies in meat dealers in Tunja, Boyacá, Colombia / Anticorpos anti-Leptospira spp. em distribuidores de carne na cidade de Tunja, Boyacá, Colômbia

ABSTRACT Leptospirosis is a zoonotic disease distributed worldwide, which is emerging as a public health problem in tropical and subtropical countries. Traditionally, it has been considered as an occupational disease. The objective of this study was to determine the serological prevalence of anti-Leptospira antibodies in meat dealers in the city of Tunja, Boyacá, Colombia. An observational, cross-sectional and descriptive study was carried out in a population of 186 operators from meat establishments in the city of Tunja. The samples were analyzed using the microagglutination test in order to determine the serovar that causes the infection. Each participant answer a survey with important questions about socio-demographic, epidemiological and occupational factors. A seroprevalence of 43% [n = 80; 95% confidence interval (CI): 36%-50%] was found. According to the serovar analysis, the distribution was: L. bratislava 30% (n = 24; 95%IC: 20%-40%), L. hardjo 21.25% (n = 17; 95%IC: 12%-30%), L. pomona 20% (n = 16; 95%IC: 11%-29%), L. icterohaemorragiae 17.5% (n = 14; 95%IC: 9%-26%), L. grippotyphosa 16.25% (n = 13; 95%IC: 8%-24%), L. canicola 16.25% (n = 13; 95%IC: 8%-24%), and L. tarassovi 11.25% (n = 9; 95%IC: 4%-18%). The prevalence rate found in this study confirms the circulation of the microorganism in these operators, which may suggest the need to reinforce hygienic-sanitary, biosecurity and prevention measures as well as the control of the disease in this population.

RESUMEN La leptospirosis es una zoonosis de distribución mundial como un problema de salud pública, en países tropicales y subtropicales. Tradicionalmente ha sido considerada como una enfermedad profesional. El objetivo de este estudio fue determinar la prevalencia serológica de anticuerpos anti-Leptospira en expendedores de carne en la ciudad de Tunja, Boyacá, Colombia. Se realizó un estudio observacional, transversal y descriptivo en una población de 186 trabajadores de expendios de carne en la ciudad de Tunja. Las muestras fueron analizadas mediante la técnica de microaglutinación para determinar el serovar que causa la infección. A cada participante se aplicó una encuesta con preguntas importantes respecto a factores sociodemográficos, epidemiológicos y laborales. Se encontró seroprevalencia del 43% [n = 80; intervalo de confianza (IC) 95%: 36%-50%]. Según el análisis por serovar, la distribución fue: L. bratislava 30% (n = 24; IC95%: 20%-40%), L. hardjo 21,25% (n = 17; IC95%: 12%-30%), L. pomona 20% (n = 16; IC95%: 11%-29%), L. icterohaemorragiae 17,50% (n = 14; IC95%: 9%-26%), L. grippotyphosa 16,25% (n = 13; IC95%: 8%-24%), L. canicola 16,25% (n = 13; IC95%: 8%-24%) y L. tarassovi 11,25% (n = 9; IC95%: 4%-18%). La prevalencia hallada en este estudio confirma la circulación del microorganismo en aquellos trabajadores, lo cual exige reforzar las medidas higiénicas, de bioseguridad y de prevención y control de la enfermedad en esa población.

RESUMO A leptospirose é uma zoonose de distribuição mundial que está emergindo como um problema de saúde pública em países tropicais e subtropicais. Tradicionalmente, tem sido considerada uma doença ocupacional. O objetivo deste estudo foi determinar a prevalência sorológica de anticorpos anti-Leptospira em distribuidores de carne na cidade de Tunja, Boyacá, Colômbia. Realizou-se um estudo observacional, transversal e descritivo em uma população de 186 trabalhadores de estabelecimentos de carne na cidade de Tunja. As amostras foram analisadas pela técnica de microaglutinação para determinar o sorovar que causa a infecção. Cada participante respondeu a um questionário com questões importantes sobre fatores sociodemográficos, epidemiológicos e trabalhistas. Foi encontrada soroprevalência de 43% [n = 80; intervalo de confiança (IC)95%: 36%-50%]. De acordo com a análise por sorovar, a distribuição foi: L. bratislava 30% (n = 24; IC95%: 20%-40%), L. hardjo 21,25% (n = 17; IC95%: 12%-30%), L. pomona 20% (n = 16; IC95%: 11%-29%), L. icterohaemorragiae 17,50% (n = 14; IC95%: 9%-26%), L. grippotyphosa 16,25% (n = 13; IC95%: 8%-24%), L. canicola 16,25% (n = 13; IC95%: 8%-24%) e L. tarassovi 11,25% (n = 9; IC95%: 4%-18%). A prevalência encontrada neste estudo confirma a circulação do microrganismo nesses trabalhadores, o que sugere a necessidade de reforçar medidas higiênicas, de biossegurança e de prevenção e controle da doença nessa população.

An Optimized Microsatellite Scheme for Assessing Populations of Xanthomonas phaseoli pv. manihotis.

Diverse molecular markers have been used to analyze the genetic diversity of plant pathogens. Compared with traditional fingerprinting methods, multiple loci variable number of tandem repeat analyses (MLVAs) have gained importance recently due to their reproducibility, high discriminatory power, ease of performance, low cost, and throughput potential. These characteristics are desirable for continuous pathogen monitoring, especially for pathogens with relatively low genetic diversity, and for disease epidemiology studies. Genetic diversity studies of Xanthomonas phaseoli pv. manihotis, which is the causal agent of cassava bacterial blight, have shown variability and changes in the bacterial population over time. Thus, an easy and fast method needs to be developed to type populations of this pathogen in different countries of the world, especially on small scales. In this study, we developed an MLVA scheme to analyze X. phaseoli pv. manihotis variability on a local scale. The MLVA-15 scheme comprises 15 variable number of tandem repeat loci grouped into four multiplex polymerase chain reaction pools. We showed that the MLVA-15 scheme had slightly higher discriminatory ability at the locality level when compared with amplified fragment length polymorphisms. The MLVA-15 scheme allowed for an accurate determination of the number of genotypes in the sample and showed reproducibility and portability. Additionally, this scheme could be used to analyze numerous strains in a reasonable timeframe. The MLVA-15 scheme was highly specific to X. phaseoli but up to eight tandem repeat loci could be amplified from other Xanthomonas spp. Finally, we assessed the utility of the scheme for analyses of X. phaseoli pv. manihotis genetic variability in the Colombian Caribbean region. MLVA-15 distinguished 88.9% of the haplotypes in our sample. Strains originating from the same field and isolated at the same time could be discriminated. In this study, the advantages of the MLVA-15 scheme targeting 6- or 7-bp repeats were demonstrated. Moreover, this scheme was a fast method that was appropriate for routine monitoring of X. phaseoli pv. manihotis populations on a local scale and, thus, was useful for addressing epidemiological questions.