Evaluation of Xanthomonas campestris survival in a soil microcosm system

Xanthomonas campestris pv. campestris is a pathogen of cruciferous plants. We studied the survival of the wild type strain and mutant derivatives which are deficient in exopolysaccharide (EPS) or in extracellular protease synthesis in soil microcosms in order to test the hypothesis that, in this environment, adherence to soil particles and scavenging of nutrients are very important strategies for bacterial survival. In sterile soil microcosms, differences in survival were only observed between the EPS producer and its mutant. In non-sterile soil experiments, survival of Prt– mutant was similar to EPS– mutant, suggesting that both characteristics have a strong influence in survival in the presence of the natural bacterial community. Bacterial decrease represented by the slope of regression lines was higher in nonsterile soil microcosms due to the influence of biotic interactions

Dinâmica da transmissão do Trypanosoma cruzi numa área rural da Argentina: III. Persistência da parasitemia pelo T. cruzi em reservatórios caninos durante um seguimento de dois anos

A new cross-sectional survey of household- associated mongrel dogs as well as follow-up of previously parasitemic individuals was carried out in 1984 toy means of xenodiagnosis and serologic techniques to get a deeper insight into the relationship of T. cruzi parasitemia and age among canine hosts in a rural area of Argentina. Persistence of detectable parasitemia was age-independent, or at most, loosely related to age, confirming the pattern observed in 1982. Similarly no significant age-decreasing effect was recorded among seropositive dogs in: a) the probability of detecting parasites in a 2-year follow-up; b) their intensity of infectiousness (=infective force) for T. infestans 3rd-4th instar nymphs, as measured by the percentage of infected bugs observed in each dog xenodiagnosis. Moreover, not only was the infective force of seropositive dogs for bugs approximately constant through lifetime, but it was significantly higher than the one recorded for children in the present survey, and for human people by other researchers. Therefore, and since T. infestans field populations show high feeding frequencies on dogs, the latter are expected to make the greatest contribution to the pool of infected vectors in the rural household of Argentina. This characteristic should be sufficient to involve canine reservoirs definitely as a risk factor for human people residing in the same house. The increased severity of parasitemia observed among dogs in this survey may be related to the acute undernutrition characteristic of canine populations of poor rural areas in our country, which is expected to affect the ability of the host to manage the infection.Foi realizada em 1984 uma nova pesquisa epidemiológica dos cães domésticos e seguimento dos indivíduos que apresentaram parasitemia dois anos antes a fim de compreender a relação entre a parasitemia e a idade dos cães, empregando para isso técnicas sorológicas e xenodiagnóstico. A persistência da parasitemia foi independente ou pouco relacionada à idade, confirmando assim o padrão observado em 1982. Da mesma maneira, nos cães soropositivos não se registrou nenhuma diminuição significativa com respeito a idade em: a) a probabilidade de descobrir parasitas por meio de um seguimento durante 2 anos; b) sua capacidade de infecção para as ninfas de 3.ª 4.ª fase de T. infestans, medido pela porcentagem de barbeiros infectados que se observou em cada um dos xenodiagnósticos dos cães. A capacidade infectante dos cães soropositivos foi aproximadamente constante ao longo da vida, e significativamente maior que a registrada para as crian. ças no presente estudo, e para os agrupamentos humanos pesquisados por outros investigadores. Assim sendo e considerando as altas freqüências de alimentação no cão que são observados nas populações pelo T. infestans, espera-se que o cão contribua para o total de barbeiros infectados existentes nas áreas rurais da Argentina. Esta característica deveria ser suficiente para incriminar definitivamente os reservatórios caninos como um fator de risco para as pessoas residentes na mesma casa. A alta intensidade da parasitemia registrada entre os cães na presente pesquisa poderia estar relacionada com a acentuada desnutrição característica dos cães nas áreas rurais pobres da Argentina, o que poderia afetar a capacidade do hospedeiro para controlar a infecção

Prospective cohort study of patients with COVID-19 hospitalized in the Internal Medicine ward of Hospital Durand: study protocol

Fil: Melendi, Santiago E. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Pérez, María M. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Salas, Cintia E. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Aguirre, Camila. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Baleta, María L. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Balsano, Facundo J. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Caldano, Mariano G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Colignon, María G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Oliveira Brasil, Thayana De. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Wolodimeroff, Nicolás de. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Déramo Aquino, Andrea I. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Fernández de Córdova, Ana G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Fontan, María B. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Galvagno, Florencia I. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Haedo, Mariana F. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Iturrieta Araya, Noelia S. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Mollinedo Cruz,Volga S. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Olivero, Agustín. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Pestalardo, Ignacio. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Ricciardi, María. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Saltos Navarrete, Jandry D. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Vera Rueda, María L. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Villaverde, María C. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Xavier, Franco B. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Lauko, Marcela. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Ujeda, Carlos. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Leis, Rocío. Hospital General de Agudos Carlos G. Durand; Argentina.INTRODUCCIÓN: Conocer los predictores de mala evolución en pacientes con Enfermedad por Coronavirus 2019 (COVID-19) permite identificar de forma temprana a los pacientes con peor pronóstico, aportando mejores herramientas a la hora de tomar decisiones clínicas. Se presenta el protocolo de un estudio de cohorte cuyo objetivo principal es identificar factores de riesgo de infección severa, critica y mortalidad en pacientes con COVID-19 internados en el Servicio de Clínica Médica del Hospital Durand (Buenos Aires, Argentina). MÉTODOS: Estudio de cohorte prospectivo con base en un único centro. Se incluirá a todos los pacientes que ingresen al servicio de Clínica Médica con diagnóstico de COVID-19 durante el periodo de estudio. Se recolectarán las características epidemiológicas, clínicas, de laboratorio, radiológicas y los datos de tratamiento, al ingreso y al momento del alta o muerte hospitalaria. El evento final primario es la muerte en la internación; los eventos secundarios son el desarrollo de enfermedad grave y enfermedad crítica, la internación en unidad cerrada y el requerimiento de asistencia respiratoria mecánica

Prospective cohort study of patients with COVID-19 hospitalized in the Internal Medicine ward of Hospital Durand: study protocol

Fil: Melendi, Santiago E. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Pérez, María M. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Salas, Cintia E. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Aguirre, Camila. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Baleta, María L. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Balsano, Facundo J. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Caldano, Mariano G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Colignon, María G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Oliveira Brasil, Thayana De. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Wolodimeroff, Nicolás de. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Déramo Aquino, Andrea I. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Fernández de Córdova, Ana G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Fontan, María B. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Galvagno, Florencia I. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Haedo, Mariana F. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Iturrieta Araya, Noelia S. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Mollinedo Cruz,Volga S. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Olivero, Agustín. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Pestalardo, Ignacio. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Ricciardi, María. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Saltos Navarrete, Jandry D. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Vera Rueda, María L. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Villaverde, María C. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Xavier, Franco B. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Lauko, Marcela. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Ujeda, Carlos. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Leis, Rocío. Hospital General de Agudos Carlos G. Durand; Argentina.INTRODUCCIÓN: Conocer los predictores de mala evolución en pacientes con Enfermedad por Coronavirus 2019 (COVID-19) permite identificar de forma temprana a los pacientes con peor pronóstico, aportando mejores herramientas a la hora de tomar decisiones clínicas. Se presenta el protocolo de un estudio de cohorte cuyo objetivo principal es identificar factores de riesgo de infección severa, critica y mortalidad en pacientes con COVID-19 internados en el Servicio de Clínica Médica del Hospital Durand (Buenos Aires, Argentina). MÉTODOS: Estudio de cohorte prospectivo con base en un único centro. Se incluirá a todos los pacientes que ingresen al servicio de Clínica Médica con diagnóstico de COVID-19 durante el periodo de estudio. Se recolectarán las características epidemiológicas, clínicas, de laboratorio, radiológicas y los datos de tratamiento, al ingreso y al momento del alta o muerte hospitalaria. El evento final primario es la muerte en la internación; los eventos secundarios son el desarrollo de enfermedad grave y enfermedad crítica, la internación en unidad cerrada y el requerimiento de asistencia respiratoria mecánica

Dynamics of transmission of Trypanosoma cruzi in a rural area of Argentina: III. Persistence of T. cruzi parasitemia among canine reservoirs in a two-year follow-up

A new cross-sectional survey of household- associated mongrel dogs as well as follow-up of previously parasitemic individuals was carried out in 1984 toy means of xenodiagnosis and serologic techniques to get a deeper insight into the relationship of T. cruzi parasitemia and age among canine hosts in a rural area of Argentina. Persistence of detectable parasitemia was age-independent, or at most, loosely related to age, confirming the pattern observed in 1982. Similarly no significant age-decreasing effect was recorded among seropositive dogs in: a) the probability of detecting parasites in a 2-year follow-up; b) their intensity of infectiousness (=infective force) for T. infestans 3rd-4th instar nymphs, as measured by the percentage of infected bugs observed in each dog xenodiagnosis. Moreover, not only was the infective force of seropositive dogs for bugs approximately constant through lifetime, but it was significantly higher than the one recorded for children in the present survey, and for human people by other researchers. Therefore, and since T. infestans field populations show high feeding frequencies on dogs, the latter are expected to make the greatest contribution to the pool of infected vectors in the rural household of Argentina. This characteristic should be sufficient to involve canine reservoirs definitely as a risk factor for human people residing in the same house. The increased severity of parasitemia observed among dogs in this survey may be related to the acute undernutrition characteristic of canine populations of poor rural areas in our country, which is expected to affect the ability of the host to manage the infection