Development of functional symbiotic white clover root hairs and nodules requires tightly regulated production of rhizobial cellulase CelC2.

The establishment of rhizobia as nitrogen-fixing endosymbionts within legume root nodules requires the disruption of the plant cell wall to breach the host barrier at strategic infection sites in the root hair tip and at points of bacterial release from infection threads (IT) within the root cortex. We previously found that Rhizobium leguminosarum bv. trifolii uses its chromosomally encoded CelC2 cellulase to erode the noncrystalline wall at the apex of root hairs, thereby creating the primary portal of its entry into white clover roots. Here, we show that a recombinant derivative of R. leguminosarum bv. trifolii ANU843 that constitutively overproduces the CelC2 enzyme has increased competitiveness in occupying aberrant nodule-like root structures on clover that are inefficient in nitrogen fixation. This aberrant symbiotic phenotype involves an extensive uncontrolled degradation of the host cell walls restricted to the expected infection sites at tips of deformed root hairs and significantly enlarged infection droplets at termini of wider IT within the nodule infection zone. Furthermore, signs of elevated plant host defense as indicated by reactive oxygen species production in root tissues were more evident during infection by the recombinant strain than its wild-type parent. Our data further support the role of the rhizobial CelC2 cell wall-degrading enzyme in primary infection, and show evidence of its importance in secondary symbiotic infection and tight regulation of its production to establish an effective nitrogen-fixing root nodule symbiosis.

Predicting adverse outcome in outpatients with acute deep vein thrombosis. findings from the RIETE Registry.

BACKGROUND: Home treatment of patients with acute deep vein thrombosis (DVT) leads to cost savings and improved quality of life. However, little information is known about what influences the clinical outcome in these patients. METHODS: The Registro Informatizado de la Enfermedad TromboEmbólica (RIETE) is an ongoing registry of consecutive patients with symptomatic, objectively confirmed, acute DVT or pulmonary embolism (PE). In this analysis evaluated the clinical outcome

Profilaxis antibiótica en odontología infantil. Puesta al día / Antibiotic prophylaxis in pediatric odontology. An update

La mayoría de las infecciones orofaciales tienen un origen odontogénico, son autolimitantes y drenan espontáneamente.Las bacterias que causan estas infecciones son generalmente saprofitas. Además los procedimientos odontológicos invasivos dan lugar a una bacteriemia transitoria.Cuando una lesión oral se contamina por una bacteria extrínseca deben administrarse la pauta antibiótica indicada, tan pronto como sea posible. En caso de pulpitis no suele estar indicado si la infección alcanza sólo al tejido pulpar o los tejidos inmediatamente adyacentes. En caso de dientes avulsionados, se aplicará antibiótico local junto con la administraciónde antibióticos sistémicos.El profesional debe conocer la severidad de la infección y el estado general del niño para considerar derivarlo al centro médico.En los pacientes cuyo sistema inmune está comprometido debe realizarse profilaxis siempre. Así como en los pacientes con problemas cardiacos asociados con endocarditis o catéteres vasculares o dispositivos protésicos.Los antibióticos administrados oralmente, efectivos ante infecciones odontogénicas es la Penicilina V asociada al ácido clavulánico. En caso de alergias, una alternativa, es la clindamicina. La mayoría de las infecciones agudas se resuelven en 3-7 días.En los últimos años, se tiende a reducir el uso general de antibióticos con propósitos preventivos o terapéuticos

Most orofacial infections are of odontogenic origin, and are of a self-limiting nature, characterized by spontaneous drainage. The causal bacteria are generally saprophytes. On the other hand, invasive dental interventions give rise to transient bacteremia.When an oral lesion is contaminated by extrinsic bacteria, the required antibiotic treatment should be provided as soon as possible. In the case of pulpitis, such treatment is usually not indicated if the infection only reaches the pulp tissue or the immediately adjacent tissues. In the event of dental avulsion, local antibiotic application is advised, in addition to the provision of systemic antibiotics.The dental professional must know the severity of the infection and the general condition of the child in order to decide referral to a medical center.Prophylaxis is required in all immunocompromised patients, as well as in individuals with cardiac problems associated with endocarditis, vascular catheters or prostheses