RESUMO
BACKGROUND & OBJECTIVES: Clostridial neurotoxins are among the most toxic substances known and cause severe illnesses in both humans and animals. A neurotoxigenic Clostridium sp. (strain RKD) isolated from intestine of decaying fish produced a novel, botulinum type B like neurotoxin as suggested by mouse bioassay, protection with anti-botulinum antibodies and PCR. The aim of the present investigation was to develop a laboratory based detection assay as an alternative to the mouse bioassay without compromising sensitivity and specificity. METHODS: Growth and toxin production were carried out in trypticase peptone yeast-extract glucose (TPYG) broth. Toxicity was estimated in terms of minimum lethal dose (MLD) by mouse bioassay. The toxin was partially purified by acid precipitation. It was used for toxoid preparation by formaldehyde treatment. This purified IgG was used for detection of neurotoxin using indirect ELISA. The culture supernatant was concentrated using a stirred cell with a 50 kDa cut-off membrane at 4 degrees C. Further purification was carried out using Prep cell. Fractions showing toxicity and sufficient purity were pooled, concentrated and analyzed on sodium dodecyl sulphatepolyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: The toxin was purified with a recovery of 8.56 per cent. Polyclonal antiserum was raised in mice using partially purified toxin with a titre of 1: 80000. A detection assay with sensitivity of approximately 15 and 300 ng/ml for partially purified and crude toxins, respectively were achieved using an indirect ELISA method. INTERPRETATION & CONCLUSION: The Clostridium sp. RKD produced a potent neurotoxin earlier shown to have novelties. A specific detection assay for the neurotoxin has been developed that may be useful both from food safety and clinical point of view.
Assuntos
Toxinas Botulínicas/isolamento & purificação , Clostridium/química , Ensaio de Imunoadsorção Enzimática/métodos , Peixes/microbiologia , Neurotoxinas/isolamento & purificação , Animais , Bioensaio , Toxinas Botulínicas/toxicidade , Toxinas Botulínicas Tipo A , Eletroforese em Gel de Poliacrilamida , Imunoglobulina G/metabolismo , Camundongos , Neurotoxinas/toxicidadeRESUMO
Adsorptive removal of water poisons such as Pb(II), Cu(II), Mn(II), Hg(II), CN(-), microbes, nerve and blister agents (concentration range from 100 to 1000 mg/L) were studied by using adsorbents such as active carbon, impregnated carbon and bentonite loaded fabric strip. Removal of water poisons (99.5%) could be achieved with an optimum stirring time of 5-15 min and weight of adsorbent of 0.8-8.0 g/100mL contaminated water, respectively. However, 85% bentonite loading was found to be most effective for Pb(II) removal. Effect of contaminants concentration was also studied.
Assuntos
Adsorção , Carbono/farmacologia , Carvão Vegetal/farmacologia , Eliminação de Resíduos Líquidos/instrumentação , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Poluentes da Água/química , Purificação da Água/métodos , Cobre/química , Chumbo/química , Manganês/química , Mercúrio/química , Metais Pesados , Água , Poluição da ÁguaRESUMO
A strain of Clostridium botulinum type E has been isolated from soil samples of Gwalior, India. The isolated strain shows curved vegetative cells with oval, bulging, and terminal spores. The production of toxin was detected by immunodiffusion test, symptomatic death of mice and mouse protection assay with trivalent antitoxin (A+B+E). The culture supernatant gave 10(3) MLD (minimum lethal dose) per ml without any protease treatment. Group specific and serotype specific primers amplified the DNA fragments of 260 bp and 445 bp, respectively, indicating Clostridium botulinum type 'E.'
