The GacS/A-Rsm Pathway Positively Regulates Motility and Flagella Synthesis in Azotobacter vinelandii.

Azotobacter vinelandii is a motile bacterium that possesses an unusual pattern of peritrichous flagellation for members of the Pseudomonadaceae family. Unlike what has been reported for Pseudomonas spp. FleQ is not the master regulator of motility in A. vinelandii, this role is performed by FlhDC. Other factors involved in the regulation of motility are AlgU (σE) and CydR which act as negative regulators. In some members of the Enterobacteriaceae and Pseudomonadaceae families, the GacS/A-Rsm pathway is another important factor regulating motility. In the present study, the involvement of the GacS/A-Rsm pathway in regulating the motility of A. vinelandii was explored; we found that contrary to what has been reported for most of the strains studied of Pseudomonas species, GacS/A, through the Rsm system, positively controlled swimming motility. We show that the target of this regulation is the synthesis of flagella, which most likely occurs in an FlhDC-independent manner.

Cromoblastomicosis en hueco poplíteo derecho, reporte de caso. puebla, méxico / Chromoblastomycosis in right popliteal fossa, case report. puebla, mexico

La Cromoblastomicosis es una micosis subcutánea producida por hongos melanizados conocidos como dematiáceos, comúnmente secundario a un proceso traumático previo. Actual mente la incidencia de esta patología es desconocida. Se presenta el caso de un hombre de 64 años originario de la comunidad de Coyomeapan, Puebla, México, quien acude por falta de cicatrización de una úlcera en hueco poplíteo derecho generada por quemadura con candil de petróleo hace cuatro años. Refiriendo dolor con leve dificultad para la deambulación y sin evidencia de sangrado activo. Se realiza raspado de la lesión con presencia de células fumagoides posteriormente se aisló Cladophialophora carrionii en Agar Boreli. Se inició tratamiento con terbinafina para su recuperación. El conocimiento de este tipo de micosis aumenta la posibilidad de un diagnóstico temprano y certero para evitar complicaciones derivadas de la cronicidad o retraso del diagnóstico.

Chromoblastomycosis is a subcutaneous mycosis produced by pigment-producing fungi known as dematiaceous, commonly after a previous traumatic process. Currently the incidence of this pathology is unknown. We present the case of a 64-year-old man from the community of Coyomeapan, Puebla, Mexico, who came for lack of healing of an ulcer in the right popliteal socket generated by burning with an oil lamp four years ago. Referring pain with mild difficulty in ambulation and without evidence of active bleeding. Scraping of the lesion was performed with the presence of fumagoid cells. Cladophialophora carrionii was isolated on Boreli Agar. Treatment was started with terbinafina for recovery. The knowledge of this type of mycosis increases the possibility of an early and accurate diagnosis to avoid complications derived from the chronicity or delay of the diagnosis.