, 2002). However, regulatory studies of the atz were not performed for a decade, likely due to the remarkable resistance of the host strain to genetic manipulation (in addition to the remarkable instability of the pADP-1 plasmid). In recent years, the use of P. putida KT2442 as a surrogate host for in vivo gene expression analysis, along with in vitro tools, has led to an indepth understanding of the regulation of the atzR-atzDEF system. This work has been a source of new insights into the previously unexplored general
nitrogen control in PF-02341066 order the genus Pseudomonas, and the molecular details of transcriptional regulation by the LTTR family. The intricacy of the regulation of the cyanuric acid degradative genes and its seamless integration in the bacterial physiology is in stark contrast to the apparently accidental and unregulated expression of the genes in the upper atrazine pathway, highlighting the notion that the atrazine-degradative Mitomycin C pathway is a patchwork assembly of newly acquired genes added to a pre-existing, mature pathway. We wish to thank Ana Belén Hervás, Inés Canosa, Manuel García-Jaramillo and Claudia Lucía Millán for their contribution to the atrazine degradation project.
Our work on the regulation of atrazine degradation has been supported by grants QLK3-CT-1999-00041 (European Union), BIO2004-01354 and BIO2007-63754 (Ministerio de Educación y Ciencia, Spain), and fellowships from the I3P (CSIC/Ministerio de Educación y Ciencia, Spain) and FPU (Ministerio de Educación y Cultura, Spain) programs, awarded to O.P. Progesterone and V.G.-G., respectively. “
“Clostridium difficile is the leading cause of bacterial antibiotic-associated diarrhoea in hospitals in the developed world. Despite this notoriety, the complex mechanisms employed by this pathogen to overcome innate host defences and induce fulminant disease are poorly understood. Various animal models have been used extensively for C. difficile research to study disease pathogenesis. Until recently, the most commonly used C. difficile disease model has utilised hamsters; however,
mouse and pig models have now been developed that unravel different aspects of C. difficile pathology. This review summarises key aspects of the small animal models currently used in C. difficile studies with a specific focus on major differences between them. Furthermore, this review highlights the advantages and disadvantages of each model and illustrates that careful consideration is required when selecting models for use in C. difficile research. “
“A defence response can be induced by nonpathogenic Fusarium oxysporum CS-20 in several crops, but the molecular mechanism has not been clearly demonstrated. In the present study, we analysed the defence mechanism of a susceptible cucumber cultivar (Cucumis sativus L. 9930) against a pathogen (F. oxysporum f. sp. cucumerinum) through the root precolonization of CS-20.