Identification of an immunogenic protein of Giardia lamblia using monoclonal antibodies generated from infected mice

The humoral immune response plays an important role in the clearance of Giardia lamblia. However, our knowledge about the specific antigens of G. lamblia that induce a protective immune response is limited. The purpose of this study was to identify and characterise the immunogenic proteins of G. lamblia in a mouse model. We generated monoclonal antibodies (moAbs) specific to G. lamblia (1B10, 2C9.D11, 3C10.E5, 3D10, 5G8.B5, 5F4, 4C7, 3C5 and 3C6) by fusing splenocytes derived from infected mice. Most of these moAbs recognised a band of ± 71 kDa (5G8 protein) and this protein was also recognised by serum from the infected mice. We found that the moAbs recognised conformational epitopes of the 5G8 protein and that this antigen is expressed on the cell surface and inside trophozoites. Additionally, antibodies specific to the 5G8 protein induced strong agglutination (> 70-90%) of trophozoites. We have thus identified a highly immunogenic antigen of G. lamblia that is recognised by the immune system of infected mice. In summary, this study describes the identification and partial characterisation of an immunogenic protein of G. lamblia. Additionally, we generated a panel of moAbs specific for this protein that will be useful for the biochemical and immunological characterisation of this immunologically interesting Giardia molecule.

Escherichia coli y Klebsiella pneumoniae comunitarias y hospitalarias productoras de β-lactamasas en hospitales de Hermosillo, Sonora / Hospital and community-acquired β-lactamases-producing Escherichia coli and Klebsiella pneumoniae at hospitals in Hermosillo, Sonora

OBJETIVO: Determinar la prevalencia de Escherichia coli y Klebsiella pneumoniae productoras de β-lactamasas de espectro extendido (BLEE) en hospitales de Hermosillo, Sonora, México. MATERIAL Y MÉTODOS: Se analizaron 1 412 aislamientos obtenidos durante un año (2008-2009). La detección de productores de BLEE se realizó por el método de sinergia de doble disco con y sin ácido clavulánico. RESULTADOS: Se aislaron E.coli y K.pneumoniae productores de BLEE hospitalarios (31.8 y 35.3 por ciento) con mayor prevalencia que los comunitarios (14.4 y 0.0 por ciento) (p<0.005). CONCLUSIONES: Nuestro estudio demuestra la presencia de microorganismos productores de BLEE en los tres hospitales.

OBJECTIVE: To determine the prevalence of extended-spectrum β-lactamases (ESBL)-producing Esherichia coli and Klebsiella pneumoniae in hospitals of Hermosillo, Sonora, Mexico. MATERIAL AND METHODS: To detect ESBL-production, 1 412 bacterial isolates obtained over a one year period (2008-2009) were analyzed using the double-disk synergy test, with and without clavulanic acid. RESULTS: Hospitalaryacquired ESBL-producing E.coli and K.pneumoniae (31.8 percent and 35.3 percent) were isolated with higher prevalence that community-acquired isolates (14.4 percent and 0.0 percent) (p<0.005). CONCLUSIONS: Our study shows the presence of ESBL-producing bacteria in the three hospitals.