Evaluación de la eficacia antibacteriana in vitro de un colutorio de aceite esencial de Origanum vulgare L. (Oregano) sobre Sterptococcos mutans

con el objetivo de evaluar la eficacia antibacteriana in vitro de dos formulaciones de un colutorio de aceite esencial de orégano sobre Streptococcus mutans (S. mutans) el principal agente causal de la placa bacteriana dental, para determinar dicha actividad, primero se realizó la determinación de la concentración inhibitoria mínima (CIM) del aceite esencial de orégano (AEO) sobre S. mutans mediante el método de microdilución en caldo y se obtuvo una CIM de 0.0025 %, esa concentración o una mayor podría ser útil en una forma farmacéutica con propósito antibacteriano. se realizó la determinación de la aptitud de los métodos de recuento microbiano que permitió indicar la metodología adecuada para evaluar la biocarga microbiana en los colutorios. Esta prueba indicó que el polisorbato 80 al 1% es un agente neutralizante idóneo para recuperar el S. mutans si se encuentra presente en los colutorios de AEO al 0.05 % y 0.10 %, y la mezcla de tiosulfato de sodio al 0.3 %, lecitina al 0.5% y polisorbato 80 al 1 % es la indicada para neutralizar las propiedades antimicrobianas del colutorio de clorhexidina al 0.12 % ylograr una recuperación adecuada del microorganismo en estudio cuando estuviera presente. Finalmente, se realizó la determinación de la eficacia antibacteriana de los colutorios de AEO, el vehículo de estos y un colutorio comercial de clorhexidina sobre S. mutans, los resultados reflejaron que el porcentaje máximo alcanzado de reducción para los colutorios de AEO al 0.05% y 0.10 % fue de 48.280 % a los 15 minutos y de 78.535 % en 1 minuto respectivamente, dichas reducciones fueron mayores que la que presento el vehículo, la cual fue de 29.292 % a los 15 minutos. El colutorio de clorhexidina al 0.12 % fue el que produjo la máxima reducción del microorganismo de estudio, la cual fue de99.996% en 6 minutos. Todos los ensayos se realizaron en el laboratorio del Centro de Investigación y Desarrollo en Salud, durante el periodo de julio a septiembre de 2015. Se concluyó que, ningún colutorio alcanzó el 99.999 % de reducción especificado por la AOAC para germicidas y sanitizantes, se observaron reducciones que sugieren buenas perspectivas de desarrollo para este tipo de formulaciones que incluyen activos de origen natural, por lo tanto se recomienda la necesidad de realizar más estudios sobre la composición y diferentes actividades del aceite esencial de orégano que pueden aprovecharse en futuras formulaciones.

Multi-Etiological Nature of Tuberculosis-Like Lesions in Condemned Pigs at the Slaughterhouse.

Tuberculosis-like lesions (TBL) in pigs have been associated with microorganisms other than mycobacteria. In this work a histopathological and microbiological evaluation of TBL in pigs is shown. A total of 352 samples belonging to 171 pigs totally condemned at slaughterhouse due to generalized TBL were sampled and selected for analysis. Pyogranulomatous (56.2%) and granulomatous lesions (20.2%) were observed in all analysed organs. Most of the granulomas observed in both lymph nodes and lungs belonged to more advanced stages of development (stages III and IV) whereas in the liver and the spleen most of lesions belonged to intermediate stages (stages II and III). Different microorganisms were simultaneously detected from TBL in the 42.7% of the animals. Mycobacterium tuberculosis complex (MTC) (38%), coryneform bacteria (40.3%) and streptococci (28.1%) were the main groups of microorganisms detected after bacteriological analysis, with Trueperella pyogenes and Streptococcus suis as the most frequently isolated species. Mycobacteria belonging to MTC were the most frequently detected pathogens in granulomatous and pyogranulomatous lesions in submandibular lymph nodes (32.7%) and coryneform bacteria were the microorganisms more frequently isolated from lungs (25.9%) and spleen samples (37.2%). These results may provide new insights into the pathogenesis and diagnosis of this pathology. The importance of coryneform bacteria and streptococci in such processes must be evaluated in future studies.

SatR is a repressor of fluoroquinolone efflux pump SatAB

Streptococcus suis is an emerging zoonotic agent responsible for high-mortality outbreaks among the human population in China. In this species, the ABC transporter SatAB mediates fluoroquinolone resistance when overexpressed. Here, we describe and characterize satR, an open reading frame (ORF) encoding a MarR superfamily regulator that acts as a repressor of satAB. satR is cotranscribed with satAB, and its interruption entails the overexpression of the pump, leading to a clinically relevant increase in resistance to fluoroquinolones.

Analysis of the genome content of Lactococcus garvieae by genomic interspecies microarray hybridization

BACKGROUND Lactococcus garvieae is a bacterial pathogen that affects different animal species in addition to humans. Despite the widespread distribution and emerging clinical significance of L. garvieae in both veterinary and human medicine, there is almost a complete lack of knowledge about the genetic content of this microorganism. In the present study, the genomic content of L. garvieae CECT 4531 was analysed using bioinformatics tools and microarray-based comparative genomic hybridization (CGH) experiments. Lactococcus lactis subsp. lactis IL1403 and Streptococcus pneumoniae TIGR4 were used as reference microorganisms. RESULTS The combination and integration of in silico analyses and in vitro CGH experiments, performed in comparison with the reference microorganisms, allowed establishment of an inter-species hybridization framework with a detection threshold based on a sequence similarity of >or= 70%. With this threshold value, 267 genes were identified as having an analogue in L. garvieae, most of which (n = 258) have been documented for the first time in this pathogen. Most of the genes are related to ribosomal, sugar metabolism or energy conversion systems. Some of the identified genes, such as als and mycA, could be involved in the pathogenesis of L. garvieae infections. CONCLUSIONS In this study, we identified 267 genes that were potentially present in L. garvieae CECT 4531. Some of the identified genes could be involved in the pathogenesis of L. garvieae infections. These results provide the first insight into the genome content of L. garvieae.

Complications of pneumococcal bacteremia after 13-valent conjugate vaccine withdrawal

In the Region of Madrid, universal immunization with the 13-serotypes pneumococcal conjugate vaccine (PCV13) started in May 2010. In July 2012, public funding ceased. Vaccination coverage decreased from >95% to 82% in 2013 and to 67% in 2014. Our aim was to investigate the impact of PCV13 withdrawal from Madrid Region's universal immunization program on the incidence of complicated pneumococcal bacteremia. We performed a multi-center retrospective cohort study, from 2009 to 2014. Participants were children aged <14 years with Streptococcus pneumoniae bacteremia. Complications were defined as any condition requiring intensive care or surgery. Sequelae were conditions lasting ≥90 days. A total of 168 patients were recruited. One-fourth of both immunized and non-immunized patients had complications. Global complications increased after PCV13 withdrawal. A total of 28% of PCV13 serotypes presented complications. Complications due to PCV13 serotypes did not increase after July 2012. No-PCV13 serotypes increased progressively from 2009 on, and 23% presented complications. A significant risk of complications was found for patients with meningitis, empyema, C-reactive protein >100 mg/L, and serotype 1. A multivariate analysis indicated that complications were associated with meningitis and hospital admission after July 2012. Sequelae were significantly associated with children <2 years of age, meningitis and no-PCV13 serotypes. The incidence of complications due to PCV13 serotypes did not increase two years after PCV13 withdrawal. Nevertheless, all-serotypes complications increased. The likely cause was that no-PCV13 serotypes (associated with meningitis) are on the rise.

Physicochemical and microbial analysis of feces from horses fed diets containing citrus pulp.

This study aimed to evaluate the e ect of diets containing increasing levels of citrus pulp on the physic-chemical and microbiological characteristics of horses feces. Five mares, at an average age of 3.5 years old and body weight of 492 ± 44.5 kg were arranged in a 5 x 5 Latin Square. The experimental diet consisted of 60% coast-cross hay and 40 % of concentrate with increasing levels of citrus pulp (0, 7, 14, 21, and 28 %). To determine the fecal pH, samples were collected directly from the oor, immediately after defecation, in the rst feces the day at 07:00 a.m., and color and fecal consistency were evaluated. For microbiological analysis, an aliquot was reserved in plastic bags, frozen, and sent to the microbiological laboratory for further analysis. Lactic acid bacteria were counted for Lactobacillus spp. and Streptococcus spp. from fecal samples under anaerobic conditions. The diet produced di erences (P<0.05) in feces consistency 98% had normal and rm stools, while 2% had loose ruminant-type feces. We observed no di erence (P<0.05) for color, verifying 100% of greenish feces, normal for equines. There was no e ect (P>0.05) on pH and on the number of Lactobacillus spp. and Streptococcus spp. The inclusion of up to 28% citrus pulp concentrates for horses did not promote change in the physio-chemical characteristics and on the population of lactic acid-producing bacteria in feces.