Lepromatous leprosy patients produce antibodies that recognise non-bilayer lipid arrangements containing mycolic acids

Non-bilayer phospholipid arrangements are three-dimensional structures that form when anionic phospholipids with an intermediate structure of the tubular hexagonal phase II are present in a bilayer of lipids. Antibodies that recognise these arrangements have been described in patients with antiphospholipid syndrome and/or systemic lupus erythematosus and in those with preeclampsia; these antibodies have also been documented in an experimental murine model of lupus, in which they are associated with immunopathology. Here, we demonstrate the presence of antibodies against non-bilayer phospholipid arrangements containing mycolic acids in the sera of lepromatous leprosy (LL) patients, but not those of healthy volunteers. The presence of antibodies that recognise these non-bilayer lipid arrangements may contribute to the hypergammaglobulinaemia observed in LL patients. We also found IgM and IgG anti-cardiolipin antibodies in 77% of the patients. This positive correlation between the anti-mycolic-non-bilayer arrangements and anti-cardiolipin antibodies suggests that both types of antibodies are produced by a common mechanism, as was demonstrated in the experimental murine model of lupus, in which there was a correlation between the anti-non-bilayer phospholipid arrangements and anti-cardiolipin antibodies. Antibodies to non-bilayer lipid arrangements may represent a previously unrecognised pathogenic mechanism in LL and the detection of these antibodies may be a tool for the early diagnosis of LL patients.

Detección de una secuencia del gene spaP de Streptococcus mutans en muestras de placa dental mediante reacción en cadena de la polimerasa (PCR) / Detection of a sequence of the spaP gen from Streptococcus mutans in dental plaque samples by means of polimerase chain reaction (PCR)

Streptococcus mutans en un patógeno relacionado con la caries dental. La determinación de la cantidad de bacterias presentes en placa dental, así como la proporción de otras bacterias en la boca, son de interés para evaluar el riesgo de caries. Es necesario establecer sistemas detección de alta sensibilidad, especificidad yque no consuman tiempo en relación a los métodos de cultivo e identificación bioquímica tradicionales y que no consumen tiempo en relación a los métodos tradicionales. Utilizando el método de PCR fue posible detectar e identificar una secuencia de 192 pb del gene spaP para evaluar la presencia de capas de S. mutans potencialmente cariogénicas, usando DNA aislado de muestras de placa dental y establecer una relación con el índice CPOD. Los resultados sugieren que es más importante la presencia de S. mutans con potencial cariogénico que la acumulación de placa, sin embargo sabemos que existen otros factores claves que contribuyen en la presencia de caries

Algunos aspectos de la bacteriología de Mycobnacterium leprae / Some aspects regarding Mycobacterium leprae bacteriology

Se brinda una información de algunos aspectos de la baceteriología de Mycobacterium leprae, a través de la historia del descubrimiento del agente causal, sus características, estructura, modelos experimentales (ratón y armadillo), antígenos carbohidratos y genética