肉毒梭菌及肉毒毒素的检验

 肉毒梭菌及肉毒毒素的检验
Examination of Clostridium botulinum and botulinus toxin

n肉毒梭菌(Clostridium botulinum)是一种厌氧的革兰氏阳性芽孢杆菌，又称为肉毒梭状芽孢杆菌。它可产生一种强烈的蛋白质外毒素——肉毒毒素(botulinum toxin)。肉毒中毒是一种比较少见但十分严重的食物中毒，死亡率高达50%以上。我国报道的中毒食物大多是家庭自制的发酵食品，如臭豆腐、豆瓣酱、面酱等，动物性食品较少见。肉毒梭菌在自然界分布很广，土壤和水中的芽孢是造成食物污染的主要来源。

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、生物学特性

革兰氏阳性大杆菌，菌端钝圆，多单在，偶见成双或短链状。有周身鞭毛，无荚膜，有卵圆形芽孢，A、B型菌的芽孢大于菌体且位于近端，使细菌呈匙形或网球拍状，其余四型芽孢不超过菌体宽度。严格的厌氧菌。对营养要求不高，可在普通培养基上生长。在血清琼脂上培养48～72h，本菌形成灰白色、中央隆起、边缘不整齐、表面粗糙的绒球状菌落。在血琼脂上，菌落周围有溶血环。在普通琼脂上可形成灰白色、半透明、边缘不整齐、呈绒毛状向外扩散的大菌落。在庖肉肉汤培养液中，全部A型菌、部分B型菌和F型菌能消化肉渣使成烂泥状，发黑并有恶臭(蛋白分解型)；全部E型菌、其余的B型菌、F型菌不消化肉渣(非蛋白分解型)。

生化特性很不规律。一般能分解葡萄糖、麦芽糖、果糖产酸产气。对麦角、凝固血清、凝固蛋白有水解作用，并引起液化。不形成靛基质。能产生硫化氢。细菌本身抵抗力不强，但芽孢抵抗力很大。根据其抗原性不同而分为A、B、C(Cα和Cβ亚型)、D、E、F、G等7个型(肉毒梭菌也据此而分为7个菌型)。引起人类中毒的主要是A、B、E三型 。肉毒毒素并不是典型的外毒素，它是在细菌死亡之后才游离出来。由于其毒性和抗原性很强，故归入外毒素。肉毒毒素对酸的抵抗力较强。

 

二、检验

一)检样的收集与处理

二)检验程序