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The objective of this study was to compare two methods of avocado graft development to determine levels of indirect resistance to Phytophthora cinnamomi. It was found that the etiolated graft method presented faster growth and greater uniformity in the lesions generated by the pathogen, which allowed for discrimination of resistance levels among genotypes. Additionally, the process of seed conditioning and production of West Indian avocado rootstocks in Colombia is described, as well as the vegetative propagation method of two avocado genotypes. A study on the development of Hass and Duke-7 avocado shoots using different methods is also presented, as well as another study on the development of the disease caused by the P. cinnamomi pathogen in avocado grafts. Finally, the potential use of avocado germplasm as rootstocks for soil stress conditions is mentioned, and other aspects related to avocado cultivation are discussed. [Extracted from the article]

Introducción: el Staphylococcus aureus causa infecciones, tanto comunitarias como hospitalarias. Se observa una resistencia antimicrobiana, por parte de este germen, en el Hospital ``Mártires del 9 de abril ´´, en Sagua la Grande. Objetivo: caracterizar la resistencia antimicrobiana del Staphylococcus aureus aislados, en muestras. Métodos: se realizó un estudio observacional, descriptivo, de corte transversal, durante el año 2022. El universo estuvo compuesto por 528 muestras positivas al Staphylococcus aureus. Se operacionalizaron las variables del sexo, la procedencia de la muestra, el tipo de muestra, la cantidad de muestras positivas al Staphylococcus aureus, durante el año 2022 y resistencia antimicrobiana, las variables se evaluaron en correspondencia con la disponibilidad de medicamentos del hospital, con estos se elaboraron tablas, se utilizó la estadística descriptiva. Resultados: resultaron 528, 3.31 % muestras positivas al Staphylococcus aureus, en 2022. Hubo predominio del sexo femenino con el (n=288, 54.55 %), el servicio con mayor incidencia fue la consulta externa con un (n=394, 74.62 %), las secreciones de la piel y partes blandas constituyó el tipo de muestra que prevaleció con el (n= 422, 79.92 %), la penicilina fue el antimicrobiano de mayor resistencia con (n=469, 88.82 %), mientras que el cloranfenicol permaneció como el de mayor sensibilidad (n=383, 72.53 %). Conclusiones: la frecuencia de aislamiento del Staphylococcus aureus, en las muestras procesadas, es baja durante el año 2022. Las cepas muestran una gran resistencia a los antibióticos, en especial a la penicilina. El cloranfenicol resulta ser el de mayor eficacia.

Resumo As parasitoses humanas como: malária, leishmanioses, doença de Chagas e tricomoníase são causadas por protozoários e apresentam elevadas taxas de prevalência e morbimortalidade. Apesar dos números alarmantes, essas doenças, ainda são negligenciadas, recebendo pouca atenção no desenvolvimento de novos fármacos e, portanto, o combate dessas enfermidades permanece um objetivo a ser alcançado. A pesquisa básica tem um papel fundamental para compreensão dos mecanismos celulares e moleculares na busca por novos alvos terapêuticos. Nesse contexto, esta revisão reúne as principais vias celulares que os protozoários Plasmodium spp., Leishmania spp., Trypanosoma cruzi e Trichomonas vaginalis utilizam para estabelecer a infecção e causar patogenicidade. Os mecanismos celulares descritos incluem: (i) adesão, invasão e saída da célula hospedeira, (ii) evasão da resposta imune do hospedeiro, (iii) comunicação celular mediada por vesículas extracelulares, (iv) peptidases e metabolismo redox, (v) morte celular e inflamassomas. De forma geral, estudos avançados têm identificado proteínas, enzimas e receptores, em nível molecular, que desempenham papéis fundamentais no estabelecimento de infecção e, portanto, constituem-se como potenciais novos alvos terapêuticos para o tratamento, diagnóstico e desenvolvimento de vacinas para controlar e erradicar essas parasitoses. Abstract The human parasitic diseases such as: malaria, Leishmaniasis, Chagas disease and trichomoniasis are caused by protozoa and present high rates of prevalence and morbimortality. However, despite the alarming numbers, these diseases are neglected, receiving little attention in the development of new drugs and, therefore, the fight against these diseases remains a goal to be achieved. Basic research plays a fundamental role in understanding cellular and molecular mechanisms in the search for new therapeutic targets. In this context, this review brings together the main cellular pathways that the protozoa Plasmodium spp., Leishmania spp., Trypanosoma cruzi and Trichomonas vaginalis use to establish infection and cause pathogenicity. The cellular mechanisms described herein include: (i) host cell adhesion, invasion, and egress, (ii) host immune response evasion, (iii) cell communication mediated by extracellular vesicles; (iv) peptidases and redox metabolism, (v) cell death and inflammasomes. In general, advanced studies have identified proteins, enzymes, receptors at the molecular level, which play key roles in the establishment of infection and, therefore, represents potential new therapeutic targets for the treatment, diagnosis and development of vaccines to control and eradicate these parasitic diseases.

La antracnosis, asociada al género fitopatógeno Colletotrichum, es una de las enfermedades más limitantes de mango en el mundo al generar daños en campo y poscosecha. El patógeno es hemibiótrofo y además puede ser endófito asintomático; asimismo, algunas especies presentan quiescencia. El papel de estos estados biológicos como fuente de inóculo es aún incierto. Se evaluó la patogenicidad de 14 aislamientos endófitos-quiescentes de Colletotrichum obtenidos de estudios previos y de un aislamiento extraído de un fruto sintomático de mango cv. Azúcar. Al describir morfométricamente (colonia) los aislamientos en cultivos monospóricos y compararlos por su tasa de crecimiento, densidad de inóculo, conidias y apresorios, se encontraron diferencias estadísticas para las primeras tres variables. Asimismo, se evaluó la patogenicidad de los morfotipos en hojas y ramas de mango cv. Azúcar mediante inoculaciones con atomizador en árboles de dos años en condiciones de trópico seco, se describieron síntomas y se evaluaron variables biológicas (número, diámetro y tasa de crecimiento de lesiones). En hojas, todos los morfotipos indujeron lesiones, pero solo hubo diferencias en la tasa de crecimiento; en ramas, se observaron diferencias altamente significativas entre morfotipos en el número y diámetro de lesiones, y diferencias en la tasa de crecimiento de estas, aunque hubo morfotipos que no indujeron daños. Hay alta variabilidad morfológica y biológica entre morfotipos de Colletotrichum, y los aislamientos endofíticos son potencialmente infectivos sobre hojas y ramas de mango cv. Azúcar.

Cronobacter spp. is a genus of Gram-negative bacteria belonging to the family Enterobacteriaceae. Species of the genus Cronobacter, particularly C. sakazakii, are implicated in the development of severe disease in newborns, which occurs with necrotizing enterocolitis, sepsis and meningitis. The disease has been frequently associated with powdered infant formula (PIF) and can therefore occur in the form of outbreaks. The genus Cronobacter has undergone extensive diversification in the course of its evolution, with some species being clearly pathogenic to humans while the impact of other species on human health is uncertain or unknown. Whole genome sequencing is used both in population genetic studies to identify the limited number of genotypes associated with the disease and to detect genes associated with antibiotic resistance or virulence, ultimately allowing more precise epidemiological links to be established between pediatric disease and infant foods. [ABSTRACT FROM AUTHOR]

Introdução: O câncer de colorretal (CCR) é um dos mais prevalentes em número de casos e mortes no mundo. A microbiota intestinal desempenha diversas funções no hospedeiro humano, podendo influenciar diretamente na saúde, afetando o metabolismo, o sistema imune e a produção de hormônios. Estudos demonstram que a microbiota intestinal desregulada ou disbiose associada aos mecanismos virulência podem estar relacionadas com o surgimento do CCR. Dentre os microrganismos que compõe a microbiota intestinal, destaca-se o Enterococcus faecalis. Esta bactéria Gram-positiva é comensal do trato gastrointestinal, contudo, pode agir como patógeno oportunista, através de mecanismos associados a virulência. Objetivo: O objetivo desse artigo de revisão foi descrever o papel dos mecanismos de virulência de E. faecalis associados ao CCR. Material e Métodos: Revisão de literatura de artigos publicados nas bases de dados Science Direct e PubMed nos últimos 20 anos (2002–2022), empregando as palavras-chaves Enterococcus, faecalis e câncer de colorretal. Resultados: De um total de 313 artigos encontrados, 39 foram incluídos para o desenvolvimento dessa revisão bibliográfica. Os mecanismos de virulência de E. faecalis mais relatados na literatura associados ao CCR são as espécies reativas de oxigênio (ERO) (58,9%), instabilidade genômica (46,1%), 4-hidroxi-2-nonenal (15,4%), gelatinase (12,8%), ácido lipoteicóico (10,2%), substância de agregação (10,2%), receptores tipo-Toll (7,7%), ativador de plasminogênio da uroquinase (2,56%) e sistema de fosfotransferase (2,56%). Conclusões: Foi possível verificar que alguns mecanismos descritos em E. faecalis, principalmente as ERO, podem ter uma associação com o desenvolvimento do CCR.

Los virus respiratorios constituyen una de las principales causas de enfermedad en los huéspedes humanos. Están asociados a patologías que pueden ser leves, y por ende, susceptibles a terapia como a enfermedades severas que terminan en la muerte del paciente. El objetivo de esta revisión fue describir las vías de transmisión y la infectividad de los virus respiratorios. Se realizó un estudio documental, donde se recopiló información del tema en las bases de datos PubMed, Web of Science, Scielo y MEDLINE. La manera como los virus respiratorios se transmiten de un huésped a otro varía. Las principales vías son la del contacto con zonas infectadas y la exposición a gotas de fluidos procedentes de huéspedes infectados. También se han reportado las vías de los aerosoles y de la contaminación inicial vía fecal-oral. En conclusión, debido a la alta infectividad de los virus respiratorios, estos se diseminan rápida y extensamente entre los huéspedes originando la enfermedad en grados que varía de leve a severa. Respiratory viruses are one of the main causes of disease in human hosts. They are associated with pathologies that can be mild, and therefore, susceptible to therapy, as well as severe diseases that end in the death of the patient. The objective of this review was to describe the transmission routes and infectivity of respiratory viruses. An investigative, retrospective, and documentary study was carried out, where information on the subject was collected in the PubMed, Web of Science, Scielo and MEDLINE databases. The way respiratory viruses are transmitted from one host to another varies. The main routes are contact with infected areas and exposure to fluid droplets from infected hosts. Aerosol routes and initial fecal-oral contamination have also been reported. In conclusion, due to the high infectivity of respiratory viruses, they spread rapidly and extensively among hosts causing disease ranging from mild to severe.

Las musáceas son muy importantes para fines de alimentación a nivel mundial, en el Ecuador estas ocupan el 20,57 % de la superficie plantada, siendo el cantón El Carmen, uno de los principales sitios dedicados a esta explotación. Por otra parte, Ralstonia solanacearum, es la causante de la enfermedad conocida como Moko de plátano, la cual puede desaparecer el 100 % de una plantación. El objetivo fue, realizar una caracterización morfológica y bioquímica de R. solanacearum Raza 2, bacteria patógena en cultivos de banano y plátano en El Carmen, Manabí, Ecuador. El análisis bioquímico y morfológico, se realizó en los laboratorios de la Universidad de las Fuerzas Armadas-ESPE considerando los protocolos establecidos por diversos autores, las muestras se tomaron de plantaciones de plátano y banano (suelo y pseudotallo georeferenciadas), con síntomas de infección del Moko. Como resultado, se identificó virulencia en la mitad de las muestras, se confirmó que la bacteria es Gram negativa, en forma de bacilo, positiva a catalasa, indol negativa, con carácter oxidativo (energía en medios anaeróbicos); y fermentativos de lactosa y glucosa, sin presencia de ácido sulfhídrico, quien no fue capaz de hidrolizar almidón, in vitro; se confirmó que la temperatura de 4°C y pH de 4,5 inhiben el aumento de estas poblaciones bacterianas, sin embargo, los rangos de 25 y 37°C con pH de 6,5 a 8,5 no resultaron ser restrictivos para su propagación, por lo que se afirma, que El Carmen cumple con los estándares requeridos, para que el patógeno prolifere de manera óptima.

Parasitism and bees: a concept revision from an ecological perspective. From the beginning all, parasites, pathogens and viruses are organisms that have a negative connotation in the field of medicine. However, the use of methodologies and terms of medicine in the field of ecology and, above all, veterinary medicine, led to this understanding of "pathogenic" organisms reaching such studies. When we look into the apicultural research bibliography, we find that these concepts sometimes are poorly distinguished and only a few early studies have been focused on bringing light on this conflictive conceptualization. Today we find a large number of scientific articles that misuse these terms and often consider them as synonyms. Throughout this review we will seek to differentiate each of these terms and generate consensus that avoids the confusion of such important ecological concepts. [ABSTRACT FROM AUTHOR]

Introduction. L. mexicana can cause two clinical forms of cutaneous leishmaniasis: localized (LCL) and diffuse (DLC). Gene expression in trypanosomatids is highly regulated at the post-transcriptional level, a massive and systematic analysis of proteins is a good approach to understand better those mechanisms that parasites have developed for increase survival and to become more pathogenic in the human host. Objective. To analyze the protein profile of L. mexicana isolates that produce LCL and DCL. Material and methods. Total protein extracts from 10 isolates of promastigotes in stationary phase were used and processed in a Q-Exactive plus mass spectrometer, bioinformatic analysis was performed. Results. 779 proteins were identified, of which 57 were differentially expressed and were used for enrichment analysis, representing the pathways of aminoacylase activity, hydrolase activity, those associated with binding to cofactors, and chaperonins. Conclusion. The proteins, FKBP and HSP60, can be studied for their clinical potential are due to the importance for parasite survival. [ABSTRACT FROM AUTHOR]

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Copyright of Revista Intropica is the property of Revista Intropica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

La pandemia de la enfermedad por coronavirus 2019 (COVID-19) fue una de las principales causas de muerte en todo el mundo en 2020. La enfermedad es causada por el coronavirus 2 (SARS-CoV-2), un virus de ARN de la subfamilia Orthocoronavirinae relacionado con otros 2 coronavirus clínicamente relevantes, SARS-CoV y MERS-CoV. Al igual que otros coronavirus y varios otros virus, el SARS-CoV-2 se originó en los murciélagos. Sin embargo, a diferencia de otros coronavirus, el SARS-CoV-2 resultó en una pandemia devastadora. La pandemia de SARS-CoV-2 continúa, debido a la evolución viral que conduce a variantes más transmisibles e inmunes evasivas. Tecnologías como la secuenciación genómica, ha impulsado el cambio de la epidemiología sindrómica a la molecular, y promete una mejor comprensión de las variantes. La pandemia de COVID-19 ha expuesto obstáculos críticos que deben abordarse para desarrollar la ciencia de las pandemias. Gran parte del progreso se está aplicando en el mundo desarrollado. Sin embargo, persisten las barreras para el uso de la epidemiología molecular en los países de ingresos bajos y medianos (LMIC), incluida la falta de logística para equipos y reactivos y la falta de capacitación en análisis. Revisamos la literatura de epidemiología molecular para comprender sus orígenes desde la epidemia de SARS (2002-2003) hasta los eventos de influenza y la pandemia actual de COVID-19. Abogamos por una mejor vigilancia genómica del SARS-CoV y por comprender la diversidad de patógenos en posibles huéspedes zoonóticos. Este trabajo requerirá capacitación en computación filogenética y de alto rendimiento para mejorar los análisis del origen y la propagación de patógenos. Los objetivos generales son comprender y reducir el riesgo de zoonosis a través de la colaboración interdisciplinaria y la reducción de las barreras logísticas.

Dieback disease caused by fungal complexes is a severe problem in mango trees (Mangifera indica). Its main symptoms are branch rot, gummosis, and finally, the tree's death. In this work, the species of the fungal complex causing mango dieback in the Manila variety in Veracruz, Mexico were identified. The in vitro interaction of two species belonging to the complex was evaluated and the severity of the co-infection in mango branches. Lasiodiplodia pseudotheobromae and Pestalotiopsis mangiferae were identified as causal agents of mango dieback in the producing area of Veracruz. In coinfected mango branches, greater severity of necrosis was observed than in individual infections. Liquid culture filtrates applied in cocultures showed different results for each species of phytopathogen. The P. mangiferae filtrate had no significant antagonistic effects on the growth of L. pseudotheobromae (inhibition of 2.68%), while the L. pseudotheobromae filtrate inhibited 41.38% of P. mangiferae. The results show that multiple infections in mango trees increase the damage caused by dieback, which could directly impact the development of control strategies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Phylogenetically, E. coli is classified into pathogenic (B2, D and F) and commensal (A, B1 and C) groups. Extraintestinal pathogenic E. coli (ExPEC) has a diverse phylogenetic origin and virulence genes that can cause everything from urinary tract infection to bacteremia. In Mexico, the characteristics of ExPEC in the pediatric population are unknown. AIM: Identify virulence genes and phylogenetic group of E. coli from extraintestinal infections of pediatric patients. MATERIAL AND METHODS: 404 E. coli isolates collected during 2013 to 2015 were included, those from extraintestinal infections were selected (n=56). Identification was carried out with MALDI-TOF, with multiple PCR the phylogenetic group was assigned, and they were classified into pathogens and commensals. Adhesion virulence genes (fimH and papC), toxins (cnf1, sat and picU) and siderophores (iucC, irp-2 and iroN) were identified by multiplex PCR. RESULTS AND DISCUSSION: 66.1% (n=37) of the isolates corresponded to bacteremia, 12.5% (n=7) ventriculitis and 5.4% (n=3) wound infections; associated with catheter, meningitis, and abscess, 3.6% (n=2) each; conjunctivitis, pneumonia and ear infection, all with 1.7% (n=1). Pathogenic phylogroups were found in 75% (n=42) and commensal ones in 25% (n=14). The virulence genes in the pathogens were: irp-2 in 80.9% (n=34); fimH 76.2% (n=32); iucC 64.3% (n=27); sat 45.2% (n=19); papC 33.3% (n=14); iroN and cnf1 were detected in 9.5% (n=4) each; In the commensals the genes found were: fimH 85.7% (n=12), iucC 57.1% (n=8), iroN 28.6% (n=4), irp-2 in 21.4% (n=3), picU was not detected. CONCLUSION: In the pathogenic phylogroups, the main virulence genes were irp-2, fimH and sat. fimH and iucC were identified in commensal. Phylogroups B2 and A were the most frequent. Genes that encode siderophores were detected in both groups, evidencing their importance in the pathogenicity of these strains. [ABSTRACT FROM AUTHOR]

BACKGROUND: Toxoplasmosis is a zoonosis caused by the parasite Toxoplasma gondii. The most affected population are pregnant women, newborns, and immunosuppressed patients. The State of Tabasco, Mexico, has both climatic and biotic conditions that favors the parasite's dissemination and perpetuation, which create its great genetic variability, and can also generate the appearance of more virulent variants. To date, 319 different genotypes have been described worldwide with a wide variation of its virulence levels in murine models. OBJECTIVE: To isolate and genotype Toxoplasma gondii from free-range chicken tissues and to predict the virulence of the obtained isolates by the identification of the associated genetic markers. METHODOLOGY: Heart and brain samples of 12 free-range chickens from seven municipalities of Tabasco were collected to attempt the parasite's isolation in mice. Obtained tachyzoites were propagated in NIH3T3 mice fibroblasts. Parasite DNA was extracted and used to genotype each isolate by Mn-PCR-RFLP of 15 T. gondii genetic markers. RESULTS: Twelve isolates were obtained in total. Two belonged to the genotype ToxoDB #8, tree ToxoDB #28, four ToxoDB #38 and three genotypes which has not yet been described or reported. The genotypes #8, #28 and #38 have already been described in States from the Center and Southwest regions of Mexico, whereas the three new genotypes have not been reported and were identified as the genotypes ToxoDB #344, #345 y #346. In virulence markers ROP18/ROP5, were identified combinations of alleles that can predict high and low virulence in murine models. CONCLUSIONS: Toxoplasma gondii is highly prevalent in Tabasco, Mexico since isolates were obtained in more than 50% of the sampled animals. From these isolates virulent and non-virulent variants in murine model are predicted, which could have a direct impact in public health. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Los factores de virulencia de patógenos se expresan una vez superan los mecanismos fisiológicos de respuesta inmune por parte del organismo, Escherichia coli (E. coli) es una bacteria que se considera un problema en salud pública en todo el mundo debido a la alta prevalencia de mecanismos de resistencia y patogenicidad que expresa, se relaciona principalmente con infecciones intestinales y es transmitida en la cadena alimenticia; los determinantes genéticos que codifican factores de virulencia se trasladan entre diferentes especies o la misma, mediante el mecanismo de transferencia horizontal de genes. El objetivo de la presente revisión es describir factores de virulencia y genes que los codifican en cepas de E. coli aisladas de animales de producción y de productos alimenticios. En las bases de datos Medline, Lilacs, ScienceDirect, Scopus, SciELO y Dialnet, se realizó búsqueda utilizando una combinación de palabras claves validadas en inglés (gen, virulence, virulence factor, infection, horizontal gene transfer, mutation and production animals). En diferentes ambientes de producción se identificó la presencia de diferentes mecanismos de virulencia que varían según la especie animal y bacteriana, los genes con mayor circulación con Stx1, Stx2 codificantes de toxinas, Saa de adhesinas, ehxA de enterohemolisina, eaeA de intimina, IpfA de fimbrias. La vigilancia y control microbiológico en el área alimenticia y de producción animal es de gran importancia para evitar posibles brotes de enfermedades en población susceptible, por efecto de los factores de virulencia.

The resistance in seedling and adult plant of 13 varieties and 37 lines of oats against stem rust caused by Puccinia graminis f. sp. avenae was evaluated. TNQ and TFQ races and isolates AMEX18.21.1.1 and AMEX18.18.1.1 for seedling evaluation; and AMEX18.18.1.1 isolate in adult plants were used. The Diamante, Menonita, Karma and Turquesa varieties were resistant in seedling to the TFQ race, but susceptible to TNQ and the isolates AMEX18.21.1.1 and AMEX18.18.1.1, the other varieties were susceptible to the two races and isolates. All varieties were susceptible to isolate AMEX18.18.1.1, in seedling, but in adult plants these were classified as susceptible, intermediate and only Teporaca was resistant. The 37 lines were classified into 17 groups by final severity and sister lines. Genotypes 25, 28, 34, 39 and 48 were seedling resistant to AMEX18.18.1.1, and the rest were susceptible. In the field all the lines were resistant and only genotype 19 of group 14, reached a 20% infection. From its response in seedlings and in adult plants of the advanced lines, it is inferred that resistance is conditioned by adult plant genes. [ABSTRACT FROM AUTHOR]

Introducción. El uso de hongos entomopatógenos representa una alternativa factible para el manejo de T. urticae, ya que pueden usarse como una solución en el reemplazo de acaricidas sintéticos. Objetivo. Evaluar la caracterización fisiológica, molecular y determinar la patogenicidad de aislamientos de Metarhizium spp. contra Tetranichus urticae en condiciones de laboratorio. Métodos. Se evaluaron siete aislamientos de Metarhizium sp., que fueron caracterizados fisiológica y molecularmente (basados en el ITS1-5.8s e ITS2 rDNA). Posteriormente, se determinó la actividad acaricida mediante el análisis de mortalidad, concentración letal media (CL 50) y tiempo letal medio (LT 50)] contra T. urticae en condiciones de laboratorio. Resultados y discusión. La secuenciación de la región de rDNA de ITS-5.8S indicó que los siete aislados pertenecen a Metarhizium anisopliae. Los resultados mostraron que los aislados, Ma114, Ma109 y Ma106 obtuvieron la mayor tasa de crecimiento radial y los aislados Ma114 y Ma108 presentaron el mayor porcentaje de germinación acumulada. Todos los aislamientos fueron patogénicos en adultos de T. urticae, causando mortalidades entre 45.0 a 85.0%. Los aislamientos más activos (Ma110, Ma109 y Ma106) obtuvieron un tiempo letal medio (TL 50 ) entre 7.2 a 10.0 días, mientras que la concentración letal mediana (CL 50 ) osciló entre 1.1x10 8 y 1.2x10 8 conidios/mL. Estos resultados son similares a los reportados por Dimbiet al. (2004) y Bugeme et al. (2014), donde mencionan que aislamientos de M. anisopliae son eficaces para el manejo de ácaros fitófagos. Conclusión . Los aislamientos Ma110, Ma109 y Ma106 son agentes prospectivos de control biológico para el manejo de T. urticae.

In 1909, Carlos Justiniano Chagas first described the clinical manifestations of Chagas disease. The hemoflagellate parasite Trypanosoma cruzi (agent) is characterized by the presence of a flagellum and of a cytostome, glycosomes, reservosomes, and a nucleus in its cytoplasm. The life cycle of T. cruzi begins when a vector defecates on the skin of a host; the feces contain metacyclic trypomastigotes, which infect vertebrate cells. The vectors of this disease are members of the subfamily Triatominae, nocturnal, hematophagous insects capable of locating hosts by heat detection. T. cruzi infection has effects on the biology of the triatomine insect, its behavior, gut function, immune system, and associated microbiota. In the mammalian host, the parasite activates innate immune responses, and host cytokines are key to either control the infection or progress to chronicity. T. cruzi exhibits a wide genetic diversity, and while it has been proved under laboratory conditions to show varying degrees if virulence and organ tropism, no clear association has been found between specific strains and the clinical picture of the disease. This review addresses the history of the discovery of Chagas disease and discusses recent aspects of T. cruzi biology that provide insight into the dynamics of transmission. [ABSTRACT FROM AUTHOR]

The production of the pepper seedling (Capsicum annuum) is affected by the fungal complex that causes the 'damping-off', in which some species of the oomycete Pythium spp., stand out. The objective of the present study was to identify the causal agent of the death of pepper plants and evaluate its pathogenicity in pepper seeds and seedlings. A fast and aggressive growing oomycete was isolate from pepper plants, morphologically identified as P. aphanidermatum based on its sexual and asexual reproduction structures and, by molecular techniques. This isolate had a high degree of in vitro pathogenicity in pre-emergence and post-emergence in chile, showing 100% mortality. In addition, it presented a high rate of mycelial growth in different culture media (V8-Agar, Corn Agar, Corn Potato Agar, Potato Dextrose Agar, Czapek & Oat Agar), being in V8-Agar medium the only medium where it developed reproduction structures sexual and asexual. The isolation presented a mycelial growth rate of 58.3 ± 0.3mm / day at 26 ± 2 °C in PDA medium. Due to its rapid growth and its high degree of pathogenicity in vitro, it is an unusual and aggressive isolate for pepper seedlings. [ABSTRACT FROM AUTHOR]

Objectives. European Foulbrood (EFB) is a severe disease that affects the first larval stages of different types of bees, including Apis mellifera. This disease is caused by the bacteria Melissococcus plutonius, spreading through contaminated food like royal jelly (RJ). In this study, some components of RJ that could affect the survival and virulence of the bacterium were characterized. Methodology. Bromatological analyses, electrophoretic protein profile, organic acid profile, and mineral content of RJs from different origins were determined. Additionally, the variations in RJs were related to the virulence of M. plutonius through in vitro infections. Contributions. The results showed that the RJs have a different chemical composition, which affects the virulence of M. plutonius. These compounds are royal jelly major protein 1 (MRJP1) and glucose oxidase (GOX), which were absent in some JRs; 10 -hydroxy-2-decenoic acid(10-HDA), whose concentration varied from 1.8 to 3.1%, and the relationship between Potassium and Sodium (K/Na) with values between 4.21 to 20.27. These parameters can be considered a reference to indirectly evaluate the susceptibility of bee colonies against EFB in different geographical locations or seasonal periods and can also be used to develop natural treatments for diseased colonies. [ABSTRACT FROM AUTHOR]

Copyright of Hungarian Medical Journal / Orvosi Hetilap is the property of Akademiai Kiado and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

La tuberculosis pulmonar es un problema de salud pública a nivel mundial. La Organización Mundial de la Salud en el año 2018 reportó alrededor de 10 millones de enfermos y 1,5 millones de muertes. Mycobacterium tuberculosis es un patógeno intracelular y el agente causal de la enfermedad. Estudios experimentales de virulencia han permitido determinar un conjunto de genes de virulencia, que le confieren la capacidad de resistir el ambiente hostil en el macrófago, superar la actividad de la respuesta inmune y persistir en el hospedero. El objetivo de la publicación es presentar una revisión de las investigaciones de los últimos 20 años que han demostrado los genes o factores de virulencia de M. tuberculosis que contribuyen a la evasión de la respuesta inmune. Según los resultados de las investigaciones, existen múltiples factores y genes de virulencia que participan en la evasión de la respuesta inmune innata como ESAT-6, PknG, PhoP, ManLAM, SapM, katG, tpx, nuoG, sodA/secA2, pknE y Rv3654c/Rv3655c, mientras existen elementos capaces de modular la respuesta inmune adaptativa. La comprensión de la interacción entre los genes de virulencia y la actividad del sistema inmune, son importantes para estudiar nuevos métodos de diagnóstico, el diseño de nuevas vacunas y por ende, mejorar las medidas de control, prevención y tratamiento de la tuberculosis.

Escherichia coli es una de las bacterias ambientales que frecuentemente se ha visto implicada en infecciones de la glándula mamaria bovina. Aunque se desconocen los factores de virulencia específicos involucrados en dicho proceso, se ha observado que las bacterias formadoras de biopelículas se asocian con infecciones persistentes. De igual forma se ha planteado que las bacterias móviles pueden ser más patógenas. El propósito del trabajo fue analizar la relación genética, capacidad de formación de biopelículas y movilidad de E. coli aislada de casos de mastitis bovina, así como la virulencia in vivo de aislados representativos. El 67.7 % de las bacterias pertenece al grupo filogenético A, el 17.6 % al grupo B1 y el 14.7 % al D. El estudio de la relación genética mediante (GTG)5 reveló que solo dos bacterias son idénticas genéticamente, el resto se organizaron en siete grupos distintos con 70 % de similitud. El 76.5 % de las bacterias fue capaz de formar biopelículas de forma fuerte, moderada o débil. Además, los genes csgA y fimA se detectaron en el 52.9 % de las bacterias formadoras de biopelículas. El análisis de movilidad mostró que el 70.6 % fue móvil. Mientras que, el análisis de patogenicidad en larvas de Galleria mellonella reveló que bacterias formadoras de películas y móviles fueron capaces de matar un mayor número de larvas a las 24 h que las no formadoras. Los resultados indican que las E. coli causantes de mastitis bovina son muy diversas y pertenecen principalmente al grupo filogenético A y que las formadoras de biopelículas y móviles son más patógenas.

The aim of the study was to molecularly identify virulence and macrolide resistance genes in clinical isolates of Streptococcus agalactiae (GBS), recovered in 2019 from vaginal discharge (n=9) and urine (n=22), from two health facilities in Lima. Identification and antimicrobial susceptibility were determined by the Vitek® 2 automated system, identification was confirmed phenotypically; macrolide resistance was determined by the D-test method. Identification of virulence genes (lmb, bca and rib) and macrolide resistance genes (ermB, ermTR and mefA) was carried out by polymerase chain reaction (PCR). The predominant macrolide resistance phenotype and genotype were cMLSb (12/31) and ermB (11/31); the most frequent virulence gene was lmb (23/31). All were sensitive to penicillin, ampicillin and vancomycin. These findings show the need to implement molecular epidemiology studies that allow adequate knowledge and follow-up of GBS in Peru. [ABSTRACT FROM AUTHOR]

Klebsiella pneumoniae (Kp) is a member of the Enterobacteriaceae family, it is an opportunistic pathogen that affects immunosuppressed individuals. K1 and K2 strains are hyper mucous that is considered an hypervirulent factor. We report a case of a female patient who developed a hepatic abscess, bacteremia and meningoencephalitis due to an hypervirulent Kp strain requiring mechanical ventilation, vasopressors, antibiotic treatment and percutaneous drainage of the liver abscess in the intensive care unit at Hospital Cayetano Heredia. The patient survived and was discharge from the hospital. This case illustrates the presence of an hypervirulent Kp strain in Peru. [ABSTRACT FROM AUTHOR]

Marigold (Tagetes erecta) is an Asteraceae plant commonly used as an ornamental and ceremonial flower during the fall season in Mexico. Marigold plants cultivated in the field presented bacterial leaf spot disease symptoms. A bacterial strain that potentially causes spot disease was isolated. The main goal of this research was to classify this bacterium and assess its pathogenicity towards marigold and other plant species. The biochemical profiling identified this strain as Pseudomonas syringae LF2012. The phylogenetic analysis of the 16S rRNA gene revealed a close relation with Pseudomonas genomospecies. The I-CeuI macro-restriction profile of the chromosomal confirmed its high degree of similarity with distinct P. syringae pathovars. P. syringae LF2012 causes spot disease when inoculated by spray in marigold leaves. Infection assays towards plants from other families (Asteraceae, Brassicaceae, Amaranthaceae, Poaceae y Solanaceae) suggested that disease might be limited to marigold plants. Furthermore, this strain causes hypersensitive-like responses in Nicotiana tabacum leaves. [ABSTRACT FROM AUTHOR]

The highlands of Southern Brazil contribute with 40% of Brazilian persimmon production. Although expanding, persimmon production faces major problems caused by anthracnose disease (black spot), including fruit rot and necrosis of leaves. Several Colletotrichum species (C. horii, C. gloeosporioides, among others) are implicated in persimmon anthracnose around the world. To identify Colletotrichum species associated with persimmon anthracnose in the highlands of Southern Brazil, 34 isolates were analyzed by ITS-rDNA partial region, GAPDH, and TUB2 partial gene sequences, morphological characteristics, and virulence on persimmon fruits and leaves. Data showed a high prevalence of C. horii (85.3%), that associated with its high virulence on fruits and leaves, confirm a considerable degree of host preference. Moreover, other species C. aenigma, C. asianum, C. fructicola, and C. nymphaeae, were identified, but the last three ones exhibited low virulence on fruits and were not able to produce symptoms on leaves. As far as we know this is the first reference on C. asianum in persimmon. The present data may contribute to a better understanding of the etiology of anthracnose in sweet persimmon in Southern Brazil, and it will be useful for epidemiological studies and the development of disease management measures. [ABSTRACT FROM AUTHOR]

S. aureus es considerado uno de los patógenos de mayor importancia en la práctica clínica diaria. Su patogenicidad está relacionada con la producción de determinantes de virulencia que incluyen factores de adherencia celular y secreción de toxinas. Se recolectaron 200 muestras de superficies ambientales de diferentes servicios hospitalarios, con la finalidad de detectar S. aureus e identificar genes que codifican para hemolisinas (hla, hlb, hld, hlg), TSST-1(tst) y PVL (lukF/lukS). La frecuencia de aislamiento fue de 3%; 6/200. La distribución fue la siguiente: emergencia (2), rayos X (1), ecografía (1), odontología (1) y vestidores (1). Los genes hla y hld fueron los más frecuentes (67% cada uno), tst se obtuvo en la mitad de las cepas y hlg se identificó en menor proporción (33%). No se detectaron genes para PLV y hemolisina β. En cada aislamiento se obtuvo dos o más genes de virulencia. Los perfiles genéticos fueron los siguientes: hla/hld (1 cepa), tst/hla/hld (1 cepa), tst/hla/hld/hlg (2 cepas). Aunque la frecuencia de S. aureus fue baja, no se debe desestimar la importancia de los ambientes hospitalarios como reservorio y fuente de trasmisión; más aún, si se considera que las cepas portaban combinaciones de genes para la TSST-1 y hemolisinas

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La tuberculosis pulmonar (TB) es un problema de salud pública a nivel mundial. La Organización Mundial de la Salud estimó para el año 2017 alrededor de 10 millones de personas enfermas y 1,3 millones de muertes. La facultad que posee MTB para modular la respuesta inmune, sobrevivir y persistir bajo el ambiente hostil en el hospedero y en la TB latente ha sido ampliamente investigada, y requiere de regulación y control de la expresión genética. El objetivo es presentar una revisión de las investigaciones relacionadas con los reguladores de la expresión de genes de MTB que están asociados con la virulencia, persistencia y supervivencia en la TB latente. Se hizo una revisión de las investigaciones de los últimos 20 años. Se concluye que MTB posee una maquinaria genética que controla la expresión de genes que participan en virulencia y persistencia, en respuesta a la hipoxia, estrés oxidativo, falta de nutrientes y pH ácido. Entre ellos, participan los sistemas de dos componentes, factores sigma y reguladores transcripcionales. En algunos casos se ha comprobado que funcionan interconectados como una red. Los hallazgos de las investigaciones aportan conocimientos para el descubrimiento de nuevos blancos para el desarrollo de drogas antituberculosas, nuevas vacunas y métodos de diagnóstico de la TB, con el propósito de proveer nuevas estrategias para el control de la enfermedad.

En la investigación se reactivaron los aislados bacterianos en medio líquido JMV para evaluar la virulencia de Burkholderia glumae frente a semillas de arroz certificadas por Fedearroz variedades F67, F68 y F2000; se procedieron a desinfectar las semillas, consecutivamente se dejaron en agua destilada estéril por 2 días; luego se secaron y se ajustó el DO del inóculo de Burkholderia glumae (aislados Bg007, Bg010 y Bg011), realizando diluciones para evaluar concentraciones desde 108 hasta 103 células por mililitro; se procedió a agitar las semillas con el inóculo, llevadas posteriormente vacío durante 10 minutos por cada dilución llevándose a cajas de Petri con papel filtro humedecido con agua destilada estéril durante 7 días; crecidas las plántulas se procedieron a medir parámetros y nivel de severidad. Se procedió a hacer el análisis estadístico mediante Software es IBM SPSS Statistics, el cual permitió obtener Gráficas De Dispersión, Diagramas De Barras De Error; Comparaciones Multivariante, la Prueba de Muestras Relacionadas se realizó a partir Comparación de las Medias. Se hizo conteo de frecuencias, junto con sus Diagramas de Frecuencias, se dividió las medidas en quintiles para realizar una escala cuantitativa de severidad. El análisis estadístico permitió evidenciar que la cepa más virulenta fue el aislado Bg007 y la menos virulenta el aislado Bg011, la variedad de arroz más afectada fue la F2000 y la menos afectada fue la F68.

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Copyright of Revista Medicina is the property of Revista Medicina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

El concepto de Una Salud se basa en la interdependencia entre la salud humana y la salud animal, vinculadas al medio ambiente en el que coexisten. Staphylococcus pseudintermedius es un microorganismo que forma parte de la microbiota de la piel y las mucosas en animales, especialmente en la especie canina de la que se suele aislar como agente etiológico de diferentes enfermedades. En los últimos años fue reconocido como un agente zoonótico. Si bien en condiciones normales no coloniza al hombre, puede causarle enfermedad bajo ciertas circunstancias. S. pseudintermedius cuenta con varios factores de virulencia, tales como enzimas, proteínas de superficie y toxinas, que participan en la adherencia, formación de biopelículas y evasión de la respuesta inmune. Posee resistencia múltiple a los agentes antimicrobianos, lo que dificulta el tratamiento de las infecciones que produce y, además, constituye un reservorio de genes de resistencia que pueden transmitirse a otras especies. Finalmente, los métodos convencionales usados en el laboratorio de diagnóstico no son suficientes para su identificación, por lo que muchas veces, no es posible confirmar su participación como agente etiológico de una enfermedad. El propósito de esta revisión fue exponer las características que permiten considerar a S. pseudintermedius en el marco de Una Salud.

Copyright of Lemir is the property of Universitat de Valencia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: The COVID-19 pandemic caused by the SARS-CoV-2 virus greatly affected healthcare workers and healthcare systems. It also challenged schools and universities worldwide negatively affecting in-person education. We conducted this study is to assess the evolution of SARs-CoV-2 virulence over the course of the pandemic., Methods: A combined cohort of University students in Spain and HCWs from the two hospitals in Spain, and one healthcare system in the Greater Boston area was followed prospectively from March 8th, 2020, to January 31st, 2022 for diagnosis with COVID-19 by PCR testing and related sequelae. Follow-up time was divided into four periods according to distinct waves of infection during the pandemic. Severity of COVID-19 was measured by case-hospitalization rate. Descriptive statistics and multivariable-adjusted statistics using the Poisson mixed-effects regression model were applied. As a sensitivity analysis, information on SARS-CoV-2 RNA in wastewater and COVID-19 deaths through May 30, 2023 from the Boston area was collected., Results: For the last two periods of the study (January 1st to December 15th, 2021 and December 16th, 2021 to January 31st, 2022) and relative to the first period (March 8th to May 31st, 2020), the incidence rate ratios (IRRs) of hospitalization were 0.08 (95% CI, 0.03-0.17) and 0.03 (95% CI, 0.01-0.15), respectively. In addition, a relative risk 0.012 CI95% (0.012-0.012) was observed when comparing COVID-19 mortality versus SARS-CoV-2 RNA copies/mL in Boston-area wastewater over the period (16th December 2021 to 30th May 2023) and relative to the first period., Conclusions: The severity of COVID-19 and immunity of our populations evolved over time, resulting in a decrease in case severity. We found the case-hospitalization rate decreased more than 90% in our cohort despite an increase in incidence., (Copyright © 2024 Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. Published by Elsevier España, S.L.U. All rights reserved.)

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cerotoma tingomariana (Coleoptera: Chrysomelidae), is one of the major pests that affect soybean crops, which can significantly reduce crop yield. The use of entomopathogenic fungi (EPF), an alternative method of control, has come into the prominence. To contribute in the management of the pest, the objective of this study was to select and characterize an entomopathogenic fungus by high efficacy and tolerance to temperature, pH and UV-B radiation. Ten fungal isolates of the fungus Beauveria bassiana and Metarhizium spp. were tested against C. tingomariana under laboratory conditions. Bv003 and Bv060 isolates were selected with mean values of LC50 were 5.6 x 104 and 5.8 x 105 conidia/mL, respectively. Bv003 was 10,4 times more virulent than Bv060. At greenhouse condition, efficacies 54.5 % and 79.5 % were obtained with the application of LC90 to adults of C. tingomariana, respectively. Both isolates had an optimal growth at pH range of 5-7, in contrast, the fungal growth was inhibited at temperatures above 30 °C and by exposure to UV-B radiation above 18,8 minutes. Finally, the isolate Bv003 was selected as a microorganism with the potential to be used as biopesticide for the control of C. tingomariana in soybean crops. [ABSTRACT FROM AUTHOR]

Copyright of Analecta Veterinaria is the property of Universidad Nacional de La Plata and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)