Multiresistance and virulence factors of Staphylococcus aureus isolated from pigs / [Multirresistência e fatores de virulência de Staphylococcus aureus isolados de suínos]

The emergence of livestock-associated methicillin-resistant Staphylococcus aureus strains (LA-MRSA) and the potential role of pigs in the evolution of these strains has led to increased interest in research of these microorganisms. However, this has contributed to a lack of research in the isolation and characterization of methicillin-susceptible S. aureus strains (MSSA). In this study, the prevalence of S. aureus in pigs in the nursery and finishing stages were analyzed. The susceptibility profiles to antibiotics, tolerance to heavy metals, and biofilm production of the isolates were evaluated using phenotypic and genotypic techniques. A total of 1,250 colonies suggestive of Staphylococcus spp. were isolated from 128 pigs, of which 63.6% (n = 795) belonged to this microbial genus. Sixty-seven colonies isolated from 34 animals (26.5%) were confirmed as S. aureus (8.4%). No strains resistant to copper, zinc, or methicillin were detected; however, all strains presented a resistance profile to at least three different classes of antimicrobials and 21 produced biofilms. These data are of concern, as they indicate the need for increased surveillance in the use of antimicrobials as well as reinforce the importance of studies on MSSA strains.(AU)

A emergência de cepas de Staphylococcus aureus resistentes à meticilina associadas à pecuária (LA-MRSA) e o papel potencial dos suínos na evolução dessas cepas têm levado ao aumento do interesse na pesquisa desses microrganismos. No entanto, isso tem contribuído para a falta de estudos sobre o isolamento e a caracterização de cepas de S. aureus sensíveis à meticilina (MSSA). Neste estudo, foi analisada a prevalência de S. aureus em suínos nas fases de creche e terminação. Os perfis de suscetibilidade aos antibióticos, a tolerância a metais pesados e a produção de biofilme dos isolados foram avaliados por meio de técnicas fenotípicas e genotípicas. Um total de 1.250 colônias sugestivas de Staphylococcus spp. foi isolado de 128 suínos, das quais 63,6% (n = 795) pertenciam a esse gênero microbiano. Sessenta e sete colônias isoladas de 34 animais (26,5%) foram confirmadas como S. aureus (8,4%). Nenhuma cepa resistente ao cobre, ao zinco ou à meticilina foi detectada; entretanto, todas as cepas apresentaram perfil de resistência a pelo menos três classes diferentes de antimicrobianos e 21 produziam biofilme. Esses dados são preocupantes, pois indicam a necessidade de maior vigilância no uso de antimicrobianos, bem como reforçam a importância de estudos com cepas de MSSA.(AU)

Rapid and long-lasting antidepressant-like effects of ketamine and their relationship with the expression of brain enzymes, BDNF, and astrocytes

Ketamine (KET) is an N-methyl-D-aspartate (NMDA) antagonist with rapid and long-lasting antidepressant effects, but how the drug shows its sustained effects is still a matter of controversy. The objectives were to evaluate the mechanisms for KET rapid (30 min) and long-lasting (15 and 30 days after) antidepressant effects in mice. A single dose of KET (2, 5, or 10 mg/kg, po) was administered to male Swiss mice and the forced swim test (FST) was performed 30 min, 15, or 30 days later. Imipramine (IMI, 30 mg/kg, ip), a tricyclic antidepressant drug, was used as reference. The mice were euthanized, separated into two time-point groups (D1, first day after KET injection; D30, 30 days later), and brain sections were processed for glycogen synthase kinase-3 (GSK-3), histone deacetylase (HDAC), brain-derived neurotrophic factor (BDNF), and glial fibrillary acidic protein (GFAP) immunohistochemical assays. KET (5 and 10 mg/kg) presented rapid and long-lasting antidepressant-like effects. As expected, the immunoreactivities for brain GSK-3 and HDAC decreased compared to control groups in all areas (striatum, DG, CA1, CA3, and mainly pre-frontal cortex, PFC) after KET injection. Increases in BDNF immunostaining were demonstrated in the PFC, DG, CA1, and CA3 areas at D1 and D30 time-points. GFAP immunoreactivity was also increased in the PFC and striatum at both time-points. In conclusion, KET changed brain BDNF and GFAP expressions 30 days after a single administration. Although neuroplasticity could be involved in the observed effects of KET, more studies are needed to explain the mechanisms for the drug's sustained antidepressant-like effects.

Relação da fáscia tóraco lombar com o mecanismo ativo de estabilização lombar / Thoraco-lumbar fascia and lumbar stabilization active mechanism relation

A região lombar desempenha um papel fundamental na acomodação de cargas decorrentes do peso corporal, da ação muscular e das forças aplicadas externamente. A funcionalidade dessa região é mantida através do sinergismo entre os mecanismos ativo, passivo e neural da estabilização lombar. O desequilíbrio proporcionará a instabilidade que terá como principal conseqüência à dor. O objetivo do estudo foi mostrar a íntima relação existente entre a Fáscia Tóraco Lombar e mecanismo ativo de estabilização lombar. A metodologia utilizada foi baseada na revisão bibliografia de estudos realizados no período de 1984 a 2004, sendo 43 artigos científicos e 10 livros. Destes, foram utilizados no trabalho, 20 artigos e 8 livros. Os bancos de dados pesquisados foram Lilás, Medline e Pedro. O estudo pôde confirmar que a Fáscia Tóraco Lombar é uma estrutura passiva que apresenta conecção com diversos músculos, comporta a função de suporte mecânico e participa dinamicamente, complementando a ação das outras estruturas estabilizadoras. Logo, a reabilitação de pacientes lombálgicos deve se basear em atividades que aprimorem a função de cada um dos componentes deste complexo mecanismo de estabilização.

The lumbar region has a major role concerning load accommodation due to body weight, muscle action and externally applied forces. The workability of this region is kept through the synergism among lumbar stabilization active, passive and neural mechanisms. Unbalance will result in instability, and pain will be its main consequence. This study aims to show the close relation between thoracolumbar fascia and the active system of lumbar stabilization. The applied methodology was based on the bibliographical review of 43 scientific articles and 10 books published between 1984 and 2004. From this whole, 8 books and 20 articles have been used in this work. The data research were Lilás, Medline and Pedro. The describers were thoracolumbar fascia, stabilization and active system. This study show that thoracolumbar fascia is a passive structure which is connected to several muscles, thus providing mechanical support, as well as dynamic cooperation to complement the action of other stabilizing structures. Lumbago patients’ rehabilitation must be based on activities which improve the function of each component in this complex stabilizing mechanism.