Tipificación y perfiles de resistencia antibiótica en unidades neonatales de Bogotá durante los años 2008-2012

La sepsis neonatal ha sido un problema en las unidades de cuidado intensivo al rededor del mundo. Su incidencia aumenta diez veces cuando el recién nacido es de muy bajo peso. El aislamiento de gérmenes resistentes en los cultivos tomados a los recién nacidos ha permitido identificar el comportamiento de los antibióticos de uso común. El presente estudio analítico de corte transversal realizado durante los años 2008 al 2012 en diez unidades de cuidados intensivos neonatales de la ciudad de Bogotá analizó la base de datos de los laboratorios de microbiología, obteniendo un total de 22.153 muestras de las cuales 7.132 ( 32.9%) fueron elegibles. Utilizando el software Whonet 5.6 y tomando solo el primer aislamiento por año y por paciente se realizaron análisis descriptivos y de resistencia bacteriana. Los resultados obtenidos fueron similares a los reportados en la literatura donde los gérmenes gran positivos son los más comúnmente aislados con un 53.2%, seguidos en importancia por los gérmenes gran negativos. Klebsiella pneumoniae y Escherichia coli en conjunto aportan 27.22%, presentando un aumento en el porcentaje de BLEE (Betalactamasa de Espectro Extendido) y aparición de carbapenemasas durante los años de estudio. El Acinetobacter baumannii ha duplicado la resistencia a ampicilina sulbactam llegando al 66.7%. Las candidas fueron aisladas en un porcentaje muy bajo sin documentarse resistencias. El Estafilococo aureus no presenta resistencias que sugiera la aparición de nuevos clones.

Antibioresistência em piómetra canina

Este estudo teve como objectivos, determinar quais são as entidades microbiológicas envolvidas no Complexo Hiperplasia Quística Endometrial - Piómetra, e eventualmente responsáveis por este tipo de patologia em Portugal, estabelecendo uma comparação com estudos prévios publicados que reflectem a realidade de outros países; determinar e documentar a ocorrência de fenómenos de resistência bacteriana para antibióticos utilizados por rotina, para terapia de situações clínicas de piómetra, no norte de Portugal; e ainda com base nos aspectos anteriores, concluir acerca do uso empírico e racional de antibióticos em situações de piómetra, identificando assim os agentes que não são eficazes no combate à infecção. As entidades envolvidas nesta patologia, são na sua maioria Escherichia coli, sendo isolada de 58% da população em estudo. No entanto, foram isoladas outras bactérias em menor número de amostras, que não tinham sido previamente identificadas como infectantes neste tipo de patologia. Pode destacar-se Peptostreptococcus anaerobius, Enterobacter aerogenes e Bacteroides fragilis. Embora com base numa amostra populacional estatisticamente não significativa, demonstrou-se no presente estudo, a ocorrência de resistência a antibióticos por parte dos microorganismos envolvidos nos quadros clínico de piómetra. Duas culturas revelaram-se multiresistentes, o que representa uma séria condicionante para sucesso terapêutico, e que pode apresentar repercussões a nível de Saúde Pública. Dos antibióticos que estavam descritos como eficazes, e que no presente estudo se demonstraram ineficazes no combate à infecção, destacam-se; a amoxicilina, a associação de amoxicilina e ácido clavulânico, a ampicilina, a cefalexina, a cefalotina, a cefazolina, a cefoxitina, a penicilina G e as sulfonamidas potenciadas.

Frequência de infecções urinárias em ambulatório : dados de um laboratório de Lisboa. Parte I

As infecções urinárias são uma das principais causas de doença em Portugal, variando conforme sejam infecções urinárias adquiridas na comunidade ou infecções urinárias nosocomiais. Neste estudo determinou-se a prevalência dos microrganismos, presentes nas amostras de urina obtidas pela técnica asséptica em doentes com infecções urinárias em ambulatório.Este estudo foi realizado no primeiro semestre do ano 2006, utilizando os dados recolhidos num laboratório de Lisboa. Foi um estudo observacional, descritivo e transversal. Foram incluídos todos os indivíduos que obtiveram um diagnóstico positivo na realização dos exames bacteriológicos (urinoculturas). Nos meses de Janeiro a Junho de 2006, primeiro semestre, foram realizadas 2820 urinoculturas, das quais 385 foram positivas. Destas, 334 (86,75%) pertenciam a indivíduos do sexo feminino e 53 a indivíduos sexo masculino (13,25%).A média de idades dos indivíduos foi de 55,25 anos (± 24,18 DP). As bactérias responsáveis pelas infecções do tracto urinário com maior frequência foram a Escherichia coli (63,6 %), Proteus spp.. (11,9 %), Enterococcus spp.. (7%) e Klebsiella spp.. (6%). Deste estudo concluiu-se que as percentagens verificadas de agentes infecciosos, responsáveis pelas infecções urinárias na comunidade, coincidem com padrões encontrados em estudos internacionais. Estas conclusões referem-se a um laboratório de Lisboa, carecendo de estudos semelhantes ao nível nacional, para caracterização do fenómeno em Portugal.

Frequência e susceptibilidade bacteriana em infecções urinárias : dados de um laboratório de Lisboa. Parte II

Este estudo teve como objectivo identificar os agentes etiológicos causadores de infecções do tracto urinário (ITU) em amostras de urina para determinar e comparar o perfil de resistência aos antibióticos nas bactérias isoladas em uroculturas, num laboratório em Lisboa (LUMILABO), durante um período de seis meses em 1997 (Maio a Outubro), com os de um período de seis meses nove anos depois, correspondentes ao 2º semestre de 2006. É umestudo observacional, descritivo e transversal, que inclui todos os indivíduos que obtiveram um diagnóstico positivo nos exames bacteriológicos num total de 3535 e 2676 uroculturas em 1997 e 2006, respectivamente, com identificação de 20 estirpes bacterianas.AE.coli foi a bactéria identificada com maior frequência em ambos os anos, seguida de P.mirabilis, Klebsiella spp. e Enterococcus spp. Emrelação à susceptibilidade aos antibióticos, verificou-se que em 1997 a E.coli, P.mirabilis e Klebsiella spp. apresentam elevada frequência de resistência aos antibióticos Ampicilina, Trimetroprim+Sulfametoxazol (SXT), e Ácido Nalidíxico, no caso da E.coli, e Furadantina no caso do P.mirabilis e Klebsiella spp.; verificou-se que em 2006 a E.coli apresenta maior resistência à Tobramicina, Norfloxacina (NOR) e Ciprofloxacina (CIP), o P.mirabilis à Ampicilina, SXT e Amoxicilina+Ácido Clavulânico, a Klebsiella spp. à Cefalexina, Nitrofurantuina e SXT, e o Enterococcus spp. à Tretraciclina, CIPe NOR. Este estudo fornece dados para o conhecimento dos diferentes agentes etiológicos mais frequentes nas ITU no laboratório LUMIBABO em períodos de seis meses distanciados de 1997 a 2006 e disponibiliza informação sobre os seus padrões de resistências, necessários para um tratamento empírico adequado.

Use of an artificial root to examine the influence of 8-hydroxyquinoline on soil microbial activity and bacterial community structure

Invasive plant species have been shown to alter the microbial community composition of the soils they invade and it is suggested that this below-ground perturbation of potential pathogens, decomposers or symbionts may feedback positively to allow invasive success. Whether these perturbations are mediated through specific components of root exudation are not understood. We focussed on 8-hydroxyquinoline, a putative allelochemical of Centaurea diffusa (diffuse knapweed) and used an artificial root system to differentiate the effects of 8-hydroxyquinoline against a background of total rhizodeposition as mimicked through supply of a synthetic exudate solution. In soil proximal (0-10 cm) to the artificial root, synthetic exudates had a highly significant (P < 0.001) influence on dehydrogenase, fluorescein diacetate hydrolysis and urease activity. in addition, 8-hydroxyquinoline was significant (p = 0.003) as a main effect on dehydrogenase activity and interacted with synthetic exudates to affect urease activity (p = 0.09). Hierarchical cluster analysis of 16S rDNA-based DGGE band patterns also identified a primary affect of synthetic exudates and a secondary affect of 8-hydroxyquinoline on bacterial community structure. Thus, we show that the artificial rhizosphere produced by the synthetic exudates was the predominant effect, but, that the influence of the 8-hydroxyquinoline signal on the activity and structure of soil microbial communities could also be detected. (C) 2009 Elsevier Ltd. All rights reserved.

Sutterella sterconcanis sp nov., isolated from canine faeces

Morphological, biochemical and molecular genetic studies were carried out on an unknown non-spore-forming, Gram-negative, rod-shaped bacterium which was isolated from dog faeces. The bacterium grew under anaerobic conditions, was asaccharolytic, resistant to 20% (v/v) bile and was oxidase- and urease-negative. Phylogenetic analysis based on comparative 16S rRNA gene sequencing showed that the unidentified bacterium clustered with Sutterella wadsworthensis, although a sequence divergence of > 5% indicated that the bacterium from dog faeces represented a previously unrecognized subline within the genus. On the basis of the presented findings, a novel species, Sutterella stercoricanis sp. nov., is described. The type strain of Sutterella stercoricanis is 5BAC4(T) ( = CCUG 47620(T) = CIP 108024(T)).

The incidence of oral Gram-negative bacteria in patients with Parkinson's disease

Background: Parkinson's disease is a common neurodegenerative disorder that affects an increasing number of older people every year. Dysphagia is not only a common feature, but one that results in poor nutrition and an increased risk of bronchopneumonia. Previous work has suggested that the oral flora is altered in patients with oral pathology. Methods: Fifty patients were assessed to quantify the incidence of oral Gram-negative bacteria. Results: Sixteen of the patients with Parkinson's disease were found to have six different Gram-negative bacilli in their oral cavities. The 20 different Gram-negative bacteria present were Escherichia coli (n=7), Klebsiella spp. (n=3), Kluyvera spp. (n=3), Serratia spp. (n=3), Proteus spp. (n=2) and Enterobacter spp. (n=2). We found that the oral cavity of 16 (32%) of the patients with Parkinson's disease was abnormally colonised with Gram-negative bacteria and that Gram-negative bacteria were more likely to occur in those patients in whom oromuscular dysfunction was present (88% vs. 21%; p<0.05). Conclusion: Further work is required to determine the association between oral flora and the pathogenic organisms found in aspiration pneumonia as well as work on innovative treatments to reduce oral Gram-negative bacteria in those patients at particular risk of aspiration pneumonia.

Culex pipiens development is greatly influenced by native bacteria and exogenous yeast

Culex pipiens is the most cosmopolitan mosquito of the Pipiens Assemblage. By studying the nature of interactions between this species and microorganisms common to its breeding environment we can unravel important pitfalls encountered during development. We tested the survival rate of larval stages, pupae and adults of a Cx. pipiens colony exposed to a variety of microorganisms in laboratory conditions and assessed the transmission to offspring (F1) by those organisms that secured development up to adulthood. Three complementary experiments were designed to: 1) explore the nutritional value of yeasts and other microorganisms during Cx. pipiens development; 2) elucidate the transstadial transmission of yeast to the host offspring; and 3) to examine the relevance of all these microorganisms in female choice for oviposition-substratum. The yeast Saccharomyces cerevisiae proved to be the most nutritional diet, but despite showing the highest survival rates, vertical transmission to F1 was never confirmed. In addition, during the oviposition trials, none of the gravid females was attracted to the yeast substratum. Notably, the two native bacterial strains, Klebsiella sp. and Aeromonas sp., were the preferred oviposition media, the same two bacteria that managed to feed neonates until molting into 2nd instar larvae. Our results not only suggest that Klebsiella sp. or Aeromonas sp. serve as attractants for oviposition habitat selection, but also nurture the most fragile instar, L1, to assure molting into a more resilient stage, L2, while yeast proves to be the most supportive diet for completing development. These experiments unearthed survival traits that might be considered in the future development of strategies of Cx. pipiens control. These studies can be extended to other members of the Pipiens Assemblage

Nitrogen Metabolism in leaves of a tank epiphytic bromeliad: Characterization of a spatial and functional division

The leaf is considered the most important vegetative organ of tank epiphytic bromeliads due to its ability to absorb and assimilate nutrients. However, little is known about the physiological characteristics of nutrient uptake and assimilation. In order to better understand the mechanisms utilized by some tank epiphytic bromeliads to optimize the nitrogen acquisition and assimilation, a study was proposed to verify the existence of a differential capacity to assimilate nitrogen in different leaf portions. The experiments were conducted using young plants of Vriesea gigantea. A nutrient solution containing NO(3)(-)/NH(4)(+) or urea as the sole nitrogen source was supplied to the tank of these plants and the activities of urease, nitrate reductase (NR), glutamine synthetase (GS) and glutamate dehydrogenase (NADH-GDH) were quantified in apical and basal leaf portions after 1, 3, 6, 9, 12, 24 and 48 h. The endogenous ammonium and urea contents were also analyzed. Independent of the nitrogen sources utilized, NR and urease activities were higher in the basal portions of leaves in all the period analyzed. On the contrary. GS and GDH activities were higher in apical part. It was also observed that the endogenous ammonium and urea had the highest contents detected in the basal region. These results suggest that the basal portion was preferentially involved in nitrate reduction and urea hydrolysis, while the apical region could be the main area responsible for ammonium assimilation through the action of GS and GDH activities. Moreover, it was possible to infer that ammonium may be transported from the base, to the apex of the leaves. In conclusion, it was suggested that a spatial and functional division in nitrogen absorption and NH(4)(+) assimilation between basal and apical leaf areas exists, ensuring that the majority of nitrogen available inside the tank is quickly used by bromeliad`s leaves. (C) 2011 Elsevier GmbH. All rights reserved.

Leukotrienes Target F-actin/Cofilin-1 to Enhance Alveolar Macrophage Anti-fungal Activity

Candida albicans is the most common opportunistic fungal pathogen and causes local and systemic disease in immunocompromised patients. Alveolar macrophages (AMs) are pivotal for the clearance of C. albicans from the lung. Activated AMs secrete 5-lipoxygenase-derived leukotrienes (LTs), which in turn enhance phagocytosis and microbicidal activity against a diverse array of pathogens. Our aim was to investigate the role of LTB(4) and LTD(4) in AM antimicrobial functions against C. albicans and the signaling pathways involved. Pharmacologic and genetic inhibition of LT biosynthesis as well as receptor antagonism reduced phagocytosis of C. albicans when compared with untreated or WT controls. Conversely, exogenous LTs of both classes augmented base-line C. albicans phagocytosis by AMs. Although LTB(4) enhanced mainly mannose receptor-dependent fungal ingestion, LTD(4) enhanced mainly dectin-1 receptor-mediated phagocytosis. LT enhancement of yeast ingestion was dependent on protein kinase C-delta (PKC delta) and PI3K but not PKC alpha and MAPK activation. Both LTs reduced activation of cofilin-1, whereas they enhanced total cellular F-actin; however, LTB(4) accomplished this through the activation of LIM kinases (LIMKs) 1 and 2, whereas LTD(4) did so exclusively via LIMK-2. Finally, both exogenous LTB(4) and LTD(4) enhanced AM fungicidal activity in an NADPH oxidase-dependent manner. Our data identify LTB(4) and LTD(4) as key mediators of innate immunity against C. albicans, which act by both distinct and conserved signaling mechanisms to enhance multiple antimicrobial functions of AMs.

Leukotrienes Produced in Allergic Lung Inflammation Activate Alveolar Macrophages

It has been well-documented that leukotrienes (LTs) are released in allergic lung inflammation and that they participate in the physiopathology of asthma. A role for LTs in innate immunity has recently emerged: Cys-LTs were shown to enhance Fc gamma R-mediated phagocytosis by alveolar macrophages (AMs). Thus, using a rat model of asthma, we evaluated Fc gamma R-mediated phagocytosis and killing of Klebsiella pneumoniae by AMs. The effect of treatment with a cys-LT antagonist (montelukast) on macrophage function was also investigated. Male Wistar rats were immunized twice with OVA/alumen intraperitoneally and challenged with OVA aerosol. After 24 h, the animals were killed, and the AMs were obtained by bronchoalveolar lavage. Macrophages were cultured with IgG-opsonized red blood cells (50: 1) or IgG-opsonized K. pneumoniae (30: 1), and phagocytosis or killing was evaluated. Leukotriene C(4) and nitric oxide were quantified by the EIA and Griess methods, respectively. The results showed that AMs from sensitized and challenged rats presented a markedly increased phagocytic capacity via Fc gamma R (10X compared to controls) and enhanced killing of K. pneumoniae (4X higher than controls). The increased phagocytosis was inhibited 15X and killing 3X by treatment of the rats with montelukast, as compared to the non-treated group. cys-LT addition increased phagocytosis in control AMs but had no effect on macrophages from allergic lungs. Montelukast reduced nitric oxide (39%) and LTC(4) (73%). These results suggest that LTs produced during allergic lung inflammation potentiate the capacity of AMs to phagocytose and kill K. pneumonia via Fc gamma R. Copyright (C) 2010 S. Karger AG, Basel

Differential kinase requirement for enhancement of Fc gamma R-mediated phagocytosis in alveolar macrophages by leukotriene B(4) vs. D(4)

In alveolar macrophages, leukotriene (IT) B(4) and cysteinyl LTs (LTC(4), LTD(4) and LTE(4)) both enhance Fc gamma receptor (Fc gamma R)-mediated phagocytosis. In the present study we investigated the role of specific PKC isoforms (PKC-alpha and -delta), the MAP kinases p38 and ERK 1/2, and PI3K in mediating the potentiation of Fc gamma R-mediated phagocytosis induced by addition of leukotrienes to the AMs. It was found that exogenously added LTB(4) and LTD(4) both enhanced PKC-delta and -alpha phosphorylation during Fc gamma R engagement. Studies with isoform-selective inhibitors indicated that exogenous LTB(4) effects were dependent on both PKC-alpha and -delta, while LTD(4) effects were exclusively due to PKC-delta activation. Although both exogenous LTB(4) and LTD(4) enhanced p38 and ERK 1/2 activation, LTB(4) required only ERK 1/2, while LTD(4) required only p38 activation. Activation by both LTs was dependent on PI3K activation. Effects of endogenous LTs on kinase activation were also investigated using selective LT receptor antagonists. Endogenous LTB(4) contributed to Fc gamma R-mediated activation of PKC-alpha, ERK 1/2 and PI3K, while endogenous cysLTs contributes to activation of PKC-delta, p38 and PI3K. Taken together, our data show that the capacities of LTB(4) and LTD(4) to enhance Fc gamma R-mediated phagocytosis reflect their differential activation of specific kinase programs. (C) 2008 Elsevier Ltd. All rights reserved.

The Challenges of Antimicrobial Resistance in Brazil

Brazil is a country with continental proportions with high geographic and economic diversity. Despite its medical centers of excellence, antimicrobial resistance poses a major therapeutic challenge. Rates of methicillin-resistant Staphylococcus aureus are up to 60% and are related to an endemic Brazilian clone. Local resistance to vancomycin in Enterococci was first related to Enterococcus faecalis, which differs from European and American epidemiology. Also, local Klebsiella pneumoniae and Escherichia coli isolates producing extended-spectrum beta-lactamases have a much higher prevalence (40%-50% and 10%-18%, respectively). Carbapenem resistance among the enterobacteriaceae group is becoming a major problem, and K. pneumoniae carbapenemase isolates have been reported in different states. Among nonfermenters, carbapenem resistance is strongly related to SPM-1 (Pseudomonasaeruginosa) and OXA-23 (Acinetobacter baumannii complex) enzymes, and a colistin-only susceptible phenotype has also emerged in these isolates, which is worrisome. Local actions without loosing the global resistance perspective will demand multidisciplinary actions, new policies, and political engagement.

Impaired phagocytosis by alveolar macrophages from diabetic rats is related to the deficient coupling of LTs to the Fe gamma R signaling cascade

Diabetic individuals are more susceptible to infections and this seems to be related to impaired phagocyte function. Alveolar macrophages (AMs) are the first barrier to prevent respiratory infections Leukotrienes (LTs) increase AM phagocytic activity via Fc gamma R. In this study, we compared AMs from diabetic and nondiabetic rats for phagocytosis via Fc gamma R and the roles of LTs and insulin Diabetes was induced in male Wistar rats by alloxan (42 mg/kg, i.v); macrophages were obtained by bronchoalveolar lavage and IgG-opsonised sheep red blood cells (IgG-SRBC) were used as targets. LTs were added to the AMs 5 min before the addition of IgG-SRBC. AMs were treated with a LT synthesis inhibitor (zileuton, 10 mu M), or antagonists of the LTB(4) receptor (CP105 696, 10 mu M) cys-LT receptor (MK571, 10 mu M), 30 or 20 min before the addition of IgG-SRBC, respectively. We found that the phagocytosis of IgG-SRBC by AMs from diabetic rats is impaired compared with non-diabetic rats. Treatment with the LT inhibitor/antagonists significantly reduced AM phagocytosis in non-diabetic but not diabetic rats. During the phagocytosis of IgG-SRBC LTB(4) and LTC(4) were produced by AMs from both groups. The addition of exogenous LTB(4) or LTD(4) potentiated phagocytosis similarly in both groups Phagocytosis was followed by the phosphorylation of PKC-delta. ERK and Akt This was reduced by zileuton treatment in AMs from non-diabetic but not diabetic rats The addition of insulin to AMs further increased the phagocytosis by increasing PKC-delta phosphorylation These results suggest that the impaired phagocytosis found in AMs from diabetic rats is related to a deficient coupling of LTs to the Fc gamma R signaling cascade and that insulin has a key role in this coupling An essential role for insulin in Innate immunity is suggested (C) 2010 Elsevier Ltd. All rights reserved.

Enzyme immobilization on Ag nanoparticles/polyaniline nanocomposites

We show a simple strategy to obtain all efficient enzymatic broelectrochemical device, in which urease was immobilized oil electroactive nanostructured membranes (ENMs) made with polyaniline and silver nanoparticles (AgNP) stabilized in polyvinyl alcohol (PAni/PVA-AgNP). Fabrication of the modified electrodes comprised the chemical deposition of polyaniline followed by drop-coating of PVA-AgNP and urease, resulting in a final ITO/PAni/PVA-AgNP/urease electrode Configuration. For comparison. the electrochemical performance of ITO/PAni/urease electrodes (without Ag nanoparticles) was also studied. The performance of the modified electrodes toward Urea hydrolysis was investigated via amperometric measurements, revealing a fast increase in cathodic current with a well-defined peak upon addition of urea to the electrolytic solution. The cathodic currents for the ITO/PAni/PVA-AgNP urease electrodes were significantly higher than for the ITO/PAni/urease electrodes. The friendly environment provided by the ITO/PAni/PVA-AgNP electrode to the immobilized enzyme promoted efficient catalytic conversion of urea into ammonium and bicarbonate tons. Using the Michaelis-Menten kinetics equation, a K(M)(aPP) of 2.7 mmol L(-1) was obtained. indicating that the electrode architecture employed may be advantageous for fabrication of enzymatic devices with improved biocatalytic properties. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.