Systematic interpretation of molecular beacon polymerase chain reaction for identifying rpoB mutations in Mycobacterium tuberculosis isolates with mixed resistant and susceptible bacteria.

Detection of multidrug-resistant tuberculosis (MDR-TB), a frequent cause of treatment failure, takes 2 or more weeks to identify by culture. Rifampicin (RIF) resistance is a hallmark of MDR-TB, and detection of mutations in the rpoB gene of Mycobacterium tuberculosis using molecular beacon probes with real-time quantitative polymerase chain reaction (qPCR) is a novel approach that takes

In situ detection of antigenic glycoproteins in Taenia solium metacestodes.

Taenia solium has a complex life cycle. Its cysticercus can lodge in the brain, causing neurocysticercosis (NCC), and the adult tapeworm's survival in the intestine results in taeniasis. In this study, the in situ detection of previously described glycoprotein antigens used for serological diagnosis of NCC and the detection of other glycoconjugates was explored in cysticerci and the surrounding porcine tissue to understand their potential role in pathogenesis. Immunohistochemistry with an antiserum specific for glycoprotein antigens rich in N-linked carbohydrates and in situ histochemistry with a battery of lectins that have affinity to a variety of glycoconjugates were performed. The glycoconjugates rich in N-linked carbohydrates were detected in the vesicular fluid and tegument of the vesicular membrane and scolex, where the parasite has direct contact with the host tissues during cysticercosis and taeniasis, respectively. Additionally, as the inflammatory response progressed, the parasite's antigenic glycoproteins were also detected in the cytoplasm of inflammatory cells in the surrounding granuloma. In contrast, the spiral canal tegument, which will be exposed to intestinal enzymes in taeniasis, had N-acetyl-galactosamine-rich mucins. Thus, the differential saccharidic composition in T. solium metacestode structures may be important for the survival of the parasite in different host sites.

Similar diagnostic performance for neurocysticercosis of three glycoprotein preparations from Taenia solium metacestodes.

The detection of antibodies to Taenia solium metacestodes is very important in the differential diagnosis of neurocysticercosis (NCC). In this study, an electroimmunotransfer blot (EITB) assay that uses an elaborate protocol with metacestode glycoproteins as antigens was compared with two other Western blots that use glycoproteins obtained using simpler methods, including an eluate from a lectin column, or the vesicular fluid (VF) of the parasite. The concordance between the three assays was 91% in patients with active NCC and 100% in patients with suspected NCC and previous documentation of negative serology. The specificities for the Western blots and the EITB assay were 98% and 100%, respectively (98% concordance). These data suggest that the simplest of these immunoassays, the one that uses the VF of T. solium metacestodes in a Western blot format, can be reliably used for the serologic diagnosis of NCC in developing countries where access to the EITB assay is difficult.

El papel de los carbohidratos en la antigenicidad de las glicoproteínas del cisticerco de la Taenia solium / Hydrocarbon role in Taenia solium cysticercus glycoproteins antigenicity

La neurocisticercosis es una infección causada por el cisticerco de la T. Solium y puede confundirse con otras afecciones del sistema nervioso central. Las glicoproteínas de 12-28 kD de este parásitos son útiles para el diagnóstico serológico de la neurocisticercosis. Estas glicoproteínas contiene abundantes carbohidratos asociados vía asparagina (tipo N). Objetivo: Determinar la contribución de los carbahidratos tipo N en la antigenicidad de las glicoproteínas. Materiales y Métodos: se purificaron las glicoproteínas de 12, 16 y 18 kD de los cisticercos utilizando un gel preparativo de poliacrilamida y se sometieron a deglicosilación enzimática con PNGase F. Luego se evaluaron los cambios en antigenicidad entre las proteínas nativas y deglicosiladas por Western blot. Resultados: los antígenos deglicosilados redujeron su peso molecular a 7 kD y perdieron parte de su antigenicidad. Esta reducción fue más notoria para la proteína de 18 kD. La cual tiene mayor contenido de carbohidratos que la de 12 y 16 kD. Conclusión: estos resultados sugieren que los carbohidratos no sólo contribuyen a la antigenicidad, sino que además causan un bloqueo estérico que inhibe que el sistema inmune detecte otros epítopes no expuesto. Estos datos sugieren que la antigenicidad de las glicoproteínas de T. Solium se debe a una combinación de epítopes sacarídicos y probablemente proteicos