RESUMO Introdução: O complexo Acinetobacter calcoaceticus-baumannii (ABC) inclui cinco espécies, sendo A. baumannii a mais importante clinicamente por carrear muitos mecanismos de resistência aos carbapenêmicos, sobretudo as oxacilinases. Objetivos: Os objetivos deste estudo foram identificar as espécies do complexo ABC, avaliar o perfil de suscetibilidade e investigar a presença de oxacilinases em isolados resistentes aos carbapenêmicos provenientes de quatro estados brasileiros. Métodos: No período do estudo, foram coletados 92 isolados do Rio Grande do Sul (RS), do Rio de Janeiro (RJ), do Paraná (PR) e de São Paulo (SP). Os isolados foram identificados por matrix-assisted laser desorption ionization-time of fight mass spectrometry (MALDI-TOF MS) e sequenciamento do gene gyrB. A avaliação da suscetibilidade foi realizada por disco-difusão e microdiluição de caldo. A presença de oxacilinases foi realizada por reação em cadeia da polimerase (PCR) multiplex in house. Resultados: Noventa e um (99%) isolados foram identificados como A. baumannii por MALDI-TOF e pelo sequenciamento. A maioria dos isolados (56; 61%) apresentou resistência aos seis agentes antimicrobianos testados. Três isolados foram resistentes à polimixina B [concentração inibitória mínima (CIM) ≥ 4 µg/ml). Oitenta (87%) isolados foram positivos para OXA-23 e 12, (13%) para OXA-24. Conclusão: Nossos resultados confirmam a disseminação do gene blaOXA-23 no Brasil e sugerem a recente emergência e disseminação do gene blaOXA-24, uma vez que ele foi identificado em três dos quatro estados amostrados.

ABSTRACT Introduction: The Acinetobacter calcoaceticus-baumannii (ABC) complex includes five species, and the A. baumannii is the most important of them because it carries mechanisms of carbapenems resistance, especially the oxacillinases. Objectives: The objectives of this study were to identify the species of the ABC complex, to evaluate the susceptibility profile and to investigate the presence of oxacillinases in carbapenems-resistant isolates from four Brazilian States. Methods: In the study period, 92 isolates from Rio Grande do Sul (RS), Rio de Janeiro (RJ), Paraná (PR) and São Paulo (SP) were collected. The isolates were identified by matrix-assisted laser desorption ionization-time of fight mass spectrometry (MALDI-TOF MS) and sequencing of gyrB gene. Evaluation of susceptibility was performed by disk diffusion and broth microdilution. The presence of oxacillinases was performed by in-house multiplex polymerase chain reaction (PCR). Results: Ninety-one (99%) isolates were identified as A. baumannii by MALDI-TOF and sequencing. The majority of isolates (56; 61%) showed resistance to the six antimicrobial agents tested. Three isolates were resistant to polymyxin B [minimum inhibitory concentration (MIC) ≥ 4 µg/ml). Eighty (87%) isolates were positive to OXA-23-like, and twelve (13%) isolates to OXA-24-like. Conclusion: Our findings confirm the knowledge about the dissemination of the blaOXA-23 gene in Brazil and suggest the recent emergence and spread of blaOXA-24 gene, since it was identified in three of the four sampled states.

AbstractPultrusion is one of several manufacturing processes for reinforced polymer composites. In this process fibers are continuously pulled through a resin bath and, after impregnation, the fiber-resin assembly is cured in a heated forming die. In order to obtain a polymeric composite with good properties (high and uniform degree of cure) and a process with a minimum of wasted energy, an optimization procedure is necessary to calculate the optimal temperature profile. The present work suggests a new strategy to minimize the energy rate taking into account the final quality of the product. For this purpose the particle swarm optimization (PSO) algorithm and the computer code DASSL were used to solve the differential algebraic equation that represents the mathematical model. The results of the optimization procedure were compared with results reported in the literature and showed that this strategy may be a good alternative to find the best operational point and to test other heat policies in order to improve the material quality and minimize the energy cost. In addition, the robustness and fast convergence of the algorithm encourage industrial implementation for the inference of the degree of cure and optimization.

Pultrusion is a composite manufacturing process in which fibers are pulled continuously through a resin bath for resin impregnation before entering into a heated die, where an exothermic cure reaction occurs. The energy needed to provide the cure reaction depends on many aspects such as cure kinetics and pulling speed. Generally, the pultrusion forming is divided in heat zones that can be heated at different temperature levels. The temperature distribution on the die surface can greatly affect material quality and energy cost. In the present work, through a CFD (Computational Fluid Dynamics) algorithm, it was possible to verify that the energy requirements can be reduced by changing the heating configuration of the pultrusion die. For this, an alternative configuration with internal heaters inside the die body was simulated. The heating rate was considered as the objective function. For the optimization study, we used a stochastic algorithm, the so-called particle swarm optimization (PSO) algorithm. The results showed that the energy spent to cure the resin-fiber system can be reduced considerably.

Resistance phenotypes characterized by minimum inhibitory concentration, disk diffusion and β-lactamase production were determined in 434 isolates from patients attending the Sexually Transmitted Disease Service at Dr. José María Cullen Hospital in Santa Fe, Argentina. Susceptibility tests to penicillin, tetracycline, ciprofloxacin, espectinomycin, azithromycin and ceftriaxone were performed. Pulsed-field gel electrophoresis was conducted made to on three ciprofloxacin-resistant isolates. Epidemiologically speaking, three interesting events should be highlighted: during 1997, plasmid-mediated high level tetracycline-resistant strains were observed (33.3%); from 2002 to 2004 a significant increase of plasmid-mediated penicillin-resistant strains was registered (9.7% to 34.8%); and in the year 2000 the first two quinolone-resistant strains emerged in the province. In our hospital, the first azithromycin-resistant isolate emerged in 2004. We therefore emphasize the importance of the Clinical Microbiology Laboratory in order to provide information for the empiric treatment of this infection.

Se determinaron los fenotipos de resistencia caracterizados por la concentración inhibitoria mínima, la difusión con discos y la producción de β-lactamasa de 434 aislamientos de Neisseria gonorrhoeae obtenidos de pacientes atendidos en el Servicio de Enfermedades de Transmisión Sexual del Hospital Dr. José María Cullen, Santa Fe, Argentina. Se realizaron pruebas de sensibilidad a los siguientes antimicrobianos: penicilina, tetraciclina, ciprofloxacina, espectinomicina, azitromicina y ceftriaxona. A tres aislamientos resistentes a ciprofloxacina se les realizó electroforesis de campo pulsado. Se destacaron tres situaciones epidemiológicas de interés: en el año 1997, alta incidencia de aislamientos con resistencia plasmídica a tetraciclina (33,3%); en el período 2002-2004, un aumento significativo de la resistencia plasmídica a penicilina (9,7% a 34,8%); y en el año 2000, la emergencia de dos de los tres primeros aislamientos con resistencia a quinolonas del país. El primer aislamiento resistente a azitromicina en nuestro hospital emerge en el 2004. Este trabajo jerarquiza el rol del Laboratorio de Microbiología Clínica en la orientación del tratamiento empírico de la gonorrea.

Resistances to airflow in beds of agro-pyron and corn employing vertical and horizontal airflow directions were measured, in order to show how designing an aeration system is affected by the size and the morphology of each kind of the grain. The airflow velocity range was 0.014-0.336 m³/s-m². Pressure drops were higher when vertical airflow direction was used. Pressure-drops increased with airflow velocity for both airflow directions. At vertical airflow direction, airflow resistance of corn was in average 57% lower than agropyron, while at horizontal airflow direction was in average 76% lower, in the same order. Mathematical models from literature were used to adjust the experimental data with the aim to predict the airflow resistance. The analysis of variance (ANOVA) demonstrated that airflow direction, velocity, kind of grain and bulk density have effect on pressure drop. The estimation of the required power ventilation -based on the predictions of Mattei model- was also realized.

An electromyographical investigation of 80 patients with chronic Chagas' disease was made. It was found that 79% of the studied patients had EMG manifestations of old and chronic denervation of the upper and lower limbs without clinical features of nervous system involvement.

Fueron estudiados 80 pacientes portadores de la forma crónica de la enfermedad de Chagas mediante el empleo de técnicas convencionales de electromiografia de detección. Los hallazgos evidenciaron en el 79% de los pacientes signos de denervación antigua tanto en miembros superiores como inferiores, aúnque con predominio en estos últimos. En ningún caso hubo manifestacionrs clínicas concomitantes.

Gastrocnemius muscle biopsies were performed in 7 subjects with chronic Chagas' disease. On clinical and laboratory grounds the selected patients were judged to be healthy, being the only abnormality found the presence of positive serum tests for Chagas' disease. Fibre type grouping of either type I or type II was observed in 5 of the 7 patients. Furthermore, in 2 of the 5 patients showing muscle fibre groupings, angular fibres reacting with NADH and non-specific sterase were also found. These observations strongly suggest denervation associated with reinervation. This picture often can be observed in the skeletal muscle of patients with well compensated denervatory conditions who do not show clinical evidences of denervation.

En 7 pacientes afectados por enfermedad de Chagas crónica se procedió al estúdio biópsico del músculo gastrocnemio. Los pacientes seleccionados mostraran como única anormalidad la presencia de tests positivos en suero para la enfermedad de Chagas. Agrupamiento de fibras musculares de tipo I y II fué observado en 5 de aquellos; en 2 de estos últimos 5 se encontro, además, fibras anguladas que se teñian intensamente con NADH y esterase no especifica. Las observaciones hechas sugirieron la presencia de denervaçión seguida por reinervación, cuadro que puede ser observado con asiduidad en el músculo esquelético de pacientes con afecciones denervatorias bien compensadas y en los que no existen evidencias clinicas de ese compromiso.