RESUMO
The symptoms and the lesions observed in the serious enteritis, often very severe, whose agent is W. perfringens A (and sometimes W. agni C) is an enterotoxin known only since the works of Hauschild (1971) and Duncan (1972). This enterotoxin is very different from the other toxinic factors of this anaerobic. This new toxin has been studied by foreign people and very little in France. It was isolated, purified and structured: it is a simple protein of PM +/- 34000, erythematous, inducing severe diarrhea, whose study was realized by the technic of ligatured ileal ansa of the rabbit. Its biosynthesis is related to the sporulation. In the experiment animal, it lyzes the intestinal villosities and denudes the membranes, what makes possible for the other toxins of A type to necrose the intestine. Its diagnostic evaluation is essential for a specific therapy.
Assuntos
Clostridium perfringens/patogenicidade , Enterocolite Pseudomembranosa/etiologia , Enterotoxinas/toxicidade , Animais , Infecções por Clostridium/metabolismo , Enterocolite Pseudomembranosa/microbiologia , Enterotoxinas/isolamento & purificação , França , HumanosRESUMO
The new phenotypic and genotypic characteristics of the anaerobic coryneforms allow us to individualize them in a new sub-genus: Coryneformis nv. sub-gen so defined: Corynebacteriaceae with morphology of true Corynebacterium from which they differ by pathogenicity, the ability to synthesize reticulo-stimulin, their cell-wall composition, thier G + C%, their anaerobic growth and their salmon-pink colonies. They differ also from the true Propionibacterium which are not pathogenic, do not synthesize the reticulo-stimulin, have cream-grey, yellor or red-brown colonies, and do synthesize cobalamine (vitamin B12).
Assuntos
Actinomycetales/classificação , AnaerobioseRESUMO
A strain of C. perfringens type A, isolated from a patient, was found to be resistant to four antibiotics: tetracycline (Tet), chloramphénicol (Chl), erythromycin (Ero) and clindamycin (Cli). Clones resistant to only two drugs (Tet-Chl or Ero-Cli), or sensitive to all drugs were found in cultures of the wild-type strain treated by acridine dyes or ethidium bromide. DNA analysis by equilibrium centrifugation confirmed that the original strain contains two resistance plasmids, one called Rip 401 (Tet-Chl) and the other Rip 402 (Ero-Cli), which represent respectively 1.8 +/- 0.2% and 2.3 +/- 0.2% of the total amount of DNA in this strain of Cl. perfrigens.
Assuntos
Clostridium perfringens/efeitos dos fármacos , Resistência Microbiana a Medicamentos , Centrifugação Isopícnica , Cloranfenicol/farmacologia , Clindamicina/farmacologia , DNA/análise , Eritromicina/farmacologia , Etídio/farmacologia , Leucomicinas/farmacologia , Lincomicina/farmacologia , Plasmídeos , Tetraciclina/farmacologiaRESUMO
In the guinea-pig isolated ileum, lanthanum increases the quantity of spontaneously released acetylcholine and induces contracture of this muscle. We have shown that the latter phenomenon is not a consequence of the former. We conclude that it could be due to the Ca++ displaced by La+++. The scorpion venom effects are abolished by lanthanum. We explain this observation by blockage of Ca++ fluxes.