Comparison of the gut microbiota froms oldier and worker castes of the termite Reticulitermes grassei

The bacterial microbiota from the whole gut of soldier and worker castes of the termite Reticulitermes grassei was isolated and studied. In addition, the 16S rDNA bacterial genes from gut DNA were PCR-amplified using Bacteria-selective primers, and the 16S rDNA amplicons subsequently cloned into Escherichia coli. Sequences of the cloned inserts were then used to determine closest relatives by comparison with published sequences and with sequences from our previous work. The clones were found to be affiliated with the phyla Spirochaetes, Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Synergistetes, Verrucomicrobia, and candidate phyla Termite Group 1 (TG1) and Termite Group 2 (TG2). No significant differences were observed with respect to the relative bacterial abundances between soldier and worker phylotypes. The phylotypes obtained in this study were compared with reported sequences from other termites, especially those of phylotypes related to Spirochaetes, Wolbachia (an Alphaproteobacteria), Actinobacteria, and TG1. Many of the clone phylotypes detected in soldiers grouped with those of workers. Moreover, clones CRgS91 (soldiers) and CRgW68 (workers), both affiliated with ‘Endomicrobia’, were the same phylotype. Soldiers and workers also seemed to have similar relative protist abundances. Heterotrophic, poly-β-hydroxyalkanoate-accumulating bacteria were isolated from the gut of soldiers and shown to be affiliated with Actinobacteria and Gammaproteobacteria. We noted that Wolbachia was detected in soldiers but not in workers. Overall, the maintenance by soldiers and workers of comparable axial and radial redox gradients in the gut is consistent with the similarities in the prokaryotes and protists comprising their microbiota (AU)

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Fiebre recurrente por borreliosis / Relapsing fever due to borreliosis

La fiebre recurrente por espiroquetas del género Borrelia es una enfermedad transmitida por vectores, infradiagnosticada en nuestro medio. Sin embargo, la existencia de una prueba fácil de realizar desde el área de urgencias debería facilitar el diagnóstico de la enfermedad. Ello es básico para iniciar una pronta terapia antibiótica, ya que reduce la elevada morbilidad que la historia natural de la enfermedad conlleva. Presentamos el caso de un niño con fiebre recurrente por Borrelia, enfermedad contraída en su país de origen

Relapsing fever caused by spirochetes of the genus Borrelia is a vector-bone disease that is currently underdiagnosed in our area. However, a readly available diagnostic test performed in the emergency department could help identify this disease. The test would be essential to start early antibiotic therapy, which, in turn, would decrease the high rate of morbidity associated with the natural history of this condition. We present the case of a child with relapsing fever caused by Borrelia, who contracted the disease in his country of origin, and was seen and diagnosed in our emergency department

An in vitro study of the susceptibility of mobile and cystic forms of Borrelia burgdorferi to tinidazole / Estudio in vitro de la susceptibilidad de las formas móviles y císticas de Borrelia burgdorferi al tinidazol

The susceptibility of mobile and cystic forms of Borrelia burgdorferi to tinidazole (TZ) was examined. The minimal bactericidal concentration (MBC) of TZ against the mobile spirochetes was >128 microg/ml at 37 degrees C in micro-oxic atmosphere when incubated for 14 days. TZ significantly reduced the conversion of mobile spirochetes to cystic forms during incubation. The MBC for older (10-months-old) cysts at 37 degrees C in a micro-oxic atmosphere was >0.5 microg/ml, but >0.125 microg/ml for young (1-day-old) cysts. Acridine orange staining, dark-field microscopy and transmission electron microscopy revealed that, when the concentration of TZ was > or = MBC, the contents of the cysts were partly degraded, core structures did not develop inside the young cysts, and the amount of RNA in these cysts decreased significantly. When cysts were exposed to TZ, both the spirochetal structures and core structures inside the cysts dissolved, and the production of blebs was significantly reduced. These observations may be valuable in the treatment of resistant infections caused by B. burgdorferi, and suggest that a combination of TZ and a macrolide antibiotic could eradicate both cystic and mobile forms of B. burgdorferi (AU)

Este estudio examina la susceptibilidad al tinidazol (TZ) de las formas móviles y císticas de Borrelia burgdorferi. La concentración bactericida mínima (CBM) de TZ para las espiroquetas móviles era >128 mg/ml a 37°C en atmosfera microóxica e incubación durante 14 días. El TZ redujo significativamente la conversión de espiroquetas móviles a la forma cística durante la incubación. La CBM para los cistos viejos (de 10 meses) a 37°C y en atmosfera microóxica era >0.5 mg/ml, mientras para los cistos jóvenes (de un día) era >0.125 mg/ml. La tinción con naranja de acridina, la microscopia de campo oscuro, y la microscopia electrónica de transmisión mostraron que cuando la concentración de TZ era ≥MBC el contenido de los cistos se degradaba parcialmente, no se desarrollaban las estructuras nucleares en el interior de los cistos jóvenes, y la cantidad de RNA en dichos cistos disminuía significativamente. Cuando los cistos se exponían a TZ, las estructuras espiroquetales y nucleares de su interior se disolvían, y la producción de vesículas se reducía significativamente. Estas observaciones pueden ser importantes en el tratamiento de infecciones resistentes causadas por B. burgdorferi, y sugieren que la combinación de TZ con un antibiótico macrólido podría erradicar tanto las formas císticas de B. burgdorferi como las móviles (AU)

Cuándo, cómo y por qué del tratamiento antibiótico e las enfermedades periodontales y perimplantarias / Antibiotic treatment in periodontal and pre-implant disease: how, when and why

En este trabajo, se revisan los criterios para el uso del tratamiento antibiótico en las enfermedades periodontales y periimplantarias, y la correlación existente entre los mecanismos etiopatogénicos de ambas. La elección racional para el tratamiento profiláctico y terapéutico se fundamenta en diversos factores y premisas que engloban, desde un punto de vista crítico y práctico, los aspectos más relevantes involucrados en la controversia actual referente al tratamiento antibiótico de las enfermedades periodontales y periimplantarias. Se propone el uso sistemático de un grupo determinado de antibióticos, y se expone un protocolo específico de actuación terapéutica antimicrobiana (AU)

The aim of this article is to review the criteria for the use of antibiotic treatment in the periodontal and perimplant disease, and the correlation existing between etiopathogenic mechanims of both. The rational action for the therapeutic and profiylactic treatment is based on several factors and premises that embody, from a critical and practical point of view, the most relevant aspects involved in the present controversy referent to the antibiotic treatment. The systematic use of a defined group of antibiotics is proposed. Furthermore, an specific protocol of antimicrobial therapeutic management is pointed out (AU)