7 research outputs found
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 Prtâ mutant was similar to EPSâ 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
DinĂąmica da transmissĂŁo do Trypanosoma cruzi numa ĂĄrea rural da Argentina: III. PersistĂȘncia da parasitemia pelo T. cruzi em reservatĂłrios 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 epidemiolĂłgica dos cĂŁes domĂ©sticos e seguimento dos indivĂduos que apresentaram parasitemia dois anos antes a fim de compreender a relação entre a parasitemia e a idade dos cĂŁes, empregando para isso tĂ©cnicas sorolĂłgicas e xenodiagnĂłstico. A persistĂȘncia da parasitemia foi independente ou pouco relacionada Ă idade, confirmando assim o padrĂŁo observado em 1982. Da mesma maneira, nos cĂŁes soropositivos nĂŁo 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.ÂȘ 4.ÂȘ fase de T. infestans, medido pela porcentagem de barbeiros infectados que se observou em cada um dos xenodiagnĂłsticos dos cĂŁes. A capacidade infectante dos cĂŁes 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 freqĂŒĂȘncias de alimentação no cĂŁo que sĂŁo observados nas populaçÔes pelo T. infestans, espera-se que o cĂŁo contribua para o total de barbeiros infectados existentes nas ĂĄreas rurais da Argentina. Esta caracterĂstica deveria ser suficiente para incriminar definitivamente os reservatĂłrios caninos como um fator de risco para as pessoas residentes na mesma casa. A alta intensidade da parasitemia registrada entre os cĂŁes na presente pesquisa poderia estar relacionada com a acentuada desnutrição caracterĂstica dos cĂŁes nas ĂĄreas 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: PĂ©rez, MarĂa 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, MarĂa 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, MarĂa G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Oliveira Brasil, Thayana De. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Wolodimeroff, NicolĂĄs de. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: DĂ©ramo Aquino, Andrea I. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: FernĂĄndez de CĂłrdova, Ana G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Fontan, MarĂa 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, AgustĂn. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Pestalardo, Ignacio. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Ricciardi, MarĂa. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Saltos Navarrete, Jandry D. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Vera Rueda, MarĂa L. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Villaverde, MarĂa 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, RocĂo. Hospital General de Agudos Carlos G. Durand; Argentina.INTRODUCCIĂN: Conocer los predictores de mala evoluciĂłn en pacientes con Enfermedad por Coronavirus 2019 (COVID-19) permite identificar de forma temprana a los pacientes con peor pronĂłstico, aportando mejores herramientas a la hora de tomar decisiones clĂnicas. Se presenta el protocolo de un estudio de cohorte cuyo objetivo principal es identificar factores de riesgo de infecciĂłn severa, critica y mortalidad en pacientes con COVID-19 internados en el Servicio de ClĂnica MĂ©dica del Hospital Durand (Buenos Aires, Argentina). MĂTODOS: Estudio de cohorte prospectivo con base en un Ășnico centro. Se incluirĂĄ a todos los pacientes que ingresen al servicio de ClĂnica MĂ©dica con diagnĂłstico de COVID-19 durante el periodo de estudio. Se recolectarĂĄn las caracterĂsticas epidemiolĂłgicas, clĂnicas, de laboratorio, radiolĂłgicas y los datos de tratamiento, al ingreso y al momento del alta o muerte hospitalaria. El evento final primario es la muerte en la internaciĂłn; los eventos secundarios son el desarrollo de enfermedad grave y enfermedad crĂtica, la internaciĂłn en unidad cerrada y el requerimiento de asistencia respiratoria mecĂĄnica
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: PĂ©rez, MarĂa 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, MarĂa 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, MarĂa G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Oliveira Brasil, Thayana De. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Wolodimeroff, NicolĂĄs de. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: DĂ©ramo Aquino, Andrea I. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: FernĂĄndez de CĂłrdova, Ana G. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Fontan, MarĂa 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, AgustĂn. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Pestalardo, Ignacio. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Ricciardi, MarĂa. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Saltos Navarrete, Jandry D. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Vera Rueda, MarĂa L. Hospital General de Agudos Carlos G. Durand; Argentina.Fil: Villaverde, MarĂa 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, RocĂo. Hospital General de Agudos Carlos G. Durand; Argentina.INTRODUCCIĂN: Conocer los predictores de mala evoluciĂłn en pacientes con Enfermedad por Coronavirus 2019 (COVID-19) permite identificar de forma temprana a los pacientes con peor pronĂłstico, aportando mejores herramientas a la hora de tomar decisiones clĂnicas. Se presenta el protocolo de un estudio de cohorte cuyo objetivo principal es identificar factores de riesgo de infecciĂłn severa, critica y mortalidad en pacientes con COVID-19 internados en el Servicio de ClĂnica MĂ©dica del Hospital Durand (Buenos Aires, Argentina). MĂTODOS: Estudio de cohorte prospectivo con base en un Ășnico centro. Se incluirĂĄ a todos los pacientes que ingresen al servicio de ClĂnica MĂ©dica con diagnĂłstico de COVID-19 durante el periodo de estudio. Se recolectarĂĄn las caracterĂsticas epidemiolĂłgicas, clĂnicas, de laboratorio, radiolĂłgicas y los datos de tratamiento, al ingreso y al momento del alta o muerte hospitalaria. El evento final primario es la muerte en la internaciĂłn; los eventos secundarios son el desarrollo de enfermedad grave y enfermedad crĂtica, la internaciĂłn en unidad cerrada y el requerimiento de asistencia respiratoria mecĂĄnica
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