ABSTRACT: Italian ryegrass (Lolium multiflorum Lam.) is a troublesome weed widely found in temperate Brazilian fields with several herbicide-resistant populations. Soil seed bank is the main source of future infestations and can be strongly affected by agricultural practices, such as crop rotation and tillage system. Therefore, this study evaluated the long-term effects of different crop rotation and tillage systems on the seed bank of Italian ryegrass. Data were collected in 2012 and 2013 in a field managed since 1985 under conventional-tillage and no-tillage and subjected to three cropping systems (monoculture, total, and partial rotation) compared to the control plot. The samples were collected at three soil depths (0-5, 5-10, and 10-20 cm) using a cylindrical soil sampler, and infestations in the field were evaluated with a sample frame of 1 m2. All cropping systems reduced the soil seed bank of Italian ryegrass, regardless of soil management and sampling depths comparing to the control plot. Total and partial rotation were more effective than soil tillage to reduce the seed bank. A larger number of seeds was observed on the surface layer (0-5 cm) for all cropping systems with more uniform distribution in the soil profile in conventional-tillage. Infestation of Italian ryegrass was greater for monoculture under no-tillage in both years, whereas in total and partial rotation, regardless of soil tillage, infestations remained below 40 seedlings m−2. Thus, strategies to reduce the soil seed bank and infestations of Italian ryegrass should focus on cropping systems with crop rotation and no-tillage.

Background: Histoplasmosis is a mycosis with a high prevalence in HIV/AIDS patients. Clinical presentation includes a wide spectrum of manifestations and diagnosis usually takes up to several weeks in patients who do not present cutaneous lesions. Aim: To determine the clinical and microbiological characteristics as well as some biochemical parameters in patients with AIDS-associated histoplasmosis without tegumentary lesions, in order to develop a guideline which enables an early empiric treatment in cases of difficult diagnosis. Methods: Medical records of 86 patients with histoplasmosis were reviewed; 31 patients with diagnosis of AIDS-associated histoplasmosis without cutaneous lesions were analyzed. Results: Fever was the most frequent symptom (96.7%), lung involvement was observed in 22 patients (70.9%), the most commonly radiological pattern was miliary pattern [(12/22), 54.5%]. Nineteen patients presented with splenomegaly. Blood culture sensitivity was 93.3% (28/30) and serology was positive only in 23.5% of the cases. Eight patients died (25.8%). Patients in which CD4+ T cell lymphocytes count was < 50 cells/μl, albumin levels < 2.5 g/dl and who presented with pancytopenia had an unfavorable outcome. Conclusions: In HIV seropositive patients with fever associated to splenomegaly and bilateral miliar pattern in chest radiography, the empiric treatment with amphotericin B must be considered if signs and symptoms of unfavorable outcome are present and due to the time that it takes to arrive at an accurate diagnosis. In order to confirm the diagnosis, all microbiological samples should be collected prior to initiating therapy.

Resumen Antecedentes: La histoplasmosis es una micosis de gran relevancia en pacientes con SIDA. El cuadro clínico puede ser muy variado y, en enfermos que no desarrollan lesiones cutáneas, el diagnóstico suele demorar varias semanas. Objetivo: Establecer pautas que permitan emplear un tratamiento empírico y precoz en pacientes con histoplasmosis asociada al SIDA sin manifestaciones tegumentarias y determinar las características clínicas, microbiológicas y algunos parámetros bioquímicos en los casos de difícil diagnóstico. Métodos: Se analizaron las historias clínicas de 86 pacientes con histoplasmosis. Fueron seleccionados 31 enfermos con histoplasmosis asociada con SIDA sin lesiones cutáneas. Resultados: La fiebre fue el síntoma más frecuente (96,7%), el compromiso pulmonar se comprobó en 22 enfermos (70,9%). El patrón radiológico más frecuentemente hallado en las radiografías de tórax fue el miliar o micronodulillar bilateral [(12/22), 54,5%]. Diecinueve enfermos presentaron esplenomegalia. Los hemocultivos demostraron una sensibilidad de 93,3% (28/30) y la serología fue positiva en 23,5% de los casos. Fallecieron ocho pacientes (25,8%). Los pacientes con recuentos de linfocitos T CD4+ menores a 50 céls/μl, albúmina menor a 2,5 g/dl y pancitopenia evidenciaron un pronóstico desfavorable. Conclusiones: En los pacientes con infección por VIH, fiebre asociada a esplenomegalia y lesiones micronodulillares bilaterales en la radiografía de tórax debe considerarse el tratamiento empírico con anfotericina B cuando existan signos o síntomas de mal pronóstico, debido al tiempo de demora hasta el diagnóstico definitivo. Previo a iniciar el tratamiento deben tomarse todas las muestras para los estudios microbiológicos que permitan confirmar luego la presunción diagnóstica.

O abscesso do músculo psoas é uma infecção pouco comum que tem sido diagnosticada de maneira crescente nos últimos anos. Apresentamos um caso de paciente com infecção avançada pelo vírus da imunodeficiência humana (HIV) que desenvolveu uma infecção disseminada por Nocardia asteroides senso estrito tipo VI, com abscesso no psoas. Em nosso conhecimento, não foram relatados na literatura outros casos de abscesso do psoas por Nocardia, no contexto da infecção por HIV.

Psoas muscle abscess is an uncommon infection that have been diagnosed increasingly in the last years. We present a case of a patient with advanced human immunodeficiency virus infection who developed a disseminated infection due to Nocardia asteroides sensu stricto type VI with psoas abscess. To our knowledge no other cases of Nocardia psoas abscess in the setting of HIV infection have been reported in the literature.