肉毒梭菌及肉毒毒素的檢驗

 肉毒梭菌及肉毒毒素的檢驗
Examination of Clostridium botulinum and botulinus toxin

n肉毒梭菌(Clostridium botulinum)是一種厭氧的革蘭氏陽性芽孢杆菌，又稱為肉毒梭狀芽孢杆菌。它可產生一種強烈的蛋白質外毒素——肉毒毒素(botulinum toxin)。肉毒中毒是一種比較少見但十分嚴重的食物中毒，死亡率高達50%以上。我國報道的中毒食物大多是家庭自製的發酵食品，如臭豆腐、豆瓣醬、麵醬等，動物性食品較少見。肉毒梭菌在自然界分布很廣，土壤和水中的芽孢是造成食物汙染的主要來源。

nFoods : Improperly processed home canned foods. and Low-acid canned foods, meats, sausage, fish

nCause of illness: Toxin produced by Clostridium botulinum    Incubation period: 12 to 36 hours

nCharacteristics of Illness: Symptoms include double vision, vertigo, inability to swallow, Nausea, vomiting, diarrhea, fatigue, headache, dry mouth, speech difficulty and progressive respiratory paralysis or respiratory failure . Nausea may also be present initially. muscle paralysis

nOnset: Symptoms may begin within 18 hrs to 2 days of ingesting the toxin.

nDuration: Greater than 65% of cases are fatal. In non-fatal botulism poisoning, recovery may take weeks to years, depending upon the severity of the poisoning.

nClostridium botulinum ----- Gram-positive, endospore-forming, rod prokaryote.

nVegetative and spore stages: note the flagella.

nCauses food poisoning (botulism), wound infections and infant botulism.

Botox Cosmetic: A Look at Looking Good

Botulinum Toxin Type A (Botox Cosmetic) is a protein complex produced by the bacterium Clostridium botulinum, which contains the same toxin that causes food poisoning. When used in a medical setting as an injectable form of sterile, purified botulinum toxin, small doses block the release of a chemical called

acetylcholine by nerve cells that signal muscle contraction. By selectively interfering with the underlying muscles' ability to contract, existing frown lines are smoothed out and, in most cases, are nearly invisible in a week.

一、生物學特性

革蘭氏陽性大杆菌，菌端鈍圓，多單在，偶見成雙或短鏈狀。有周身鞭毛，無莢膜，有卵圓形芽孢，A、B型菌的芽孢大於菌體且位於近端，使細菌呈匙形或網球拍狀，其餘四型芽孢不超過菌體寬度。嚴格的厭氧菌。對營養要求不高，可在普通培養基上生長。在血清瓊脂上培養48～72h，本菌形成灰白色、中央隆起、邊緣不整齊、表麵粗糙的絨球狀菌落。在血瓊脂上，菌落周圍有溶血環。在普通瓊脂上可形成灰白色、半透明、邊緣不整齊、呈絨毛狀向外擴散的大菌落。在庖肉肉湯培養液中，全部A型菌、部分B型菌和F型菌能消化肉渣使成爛泥狀，發黑並有惡臭(蛋白分解型)；全部E型菌、其餘的B型菌、F型菌不消化肉渣(非蛋白分解型)。

生化特性很不規律。一般能分解葡萄糖、麥芽糖、果糖產酸產氣。對麥角、凝固血清、凝固蛋白有水解作用，並引起液化。不形成靛基質。能產生硫化氫。細菌本身抵抗力不強，但芽孢抵抗力很大。根據其抗原性不同而分為A、B、C(Cα和Cβ亞型)、D、E、F、G等7個型(肉毒梭菌也據此而分為7個菌型)。引起人類中毒的主要是A、B、E三型 。肉毒毒素並不是典型的外毒素，它是在細菌死亡之後才遊離出來。由於其毒性和抗原性很強，故歸入外毒素。肉毒毒素對酸的抵抗力較強。

 

二、檢驗

一)檢樣的收集與處理

二)檢驗程序