Bacteria toxins

Cyanobacterial (Blue-Green Bacteria) Toxins. Cyanobacterial poisonings were first recognized in the late 1800s. Human poisonings are rare however, kills of livestock, other mammals, birds, fish, and aquatic invertebrates are common. It is caused by a variety of biotoxins and cytotoxins, including anatoxin, microcystin, and nodularin produced by several species of cyanobacteria, including Anabaena, Aphanizomenon, Nodularia, Oscillatoria, and Microcystis. The main contamination problems include all eutrophic freshwater rivers, lakes, and streams. 

Kaolin is a naturally occurring hydrated magnesium aluminum silicate (attapulgite), and pectin is an indigestible carbohydrate derived from apples. Both appear to act as absorbents of bacteria, toxins, and fluid, thereby decreasing stool liquidity and number. They may be useful in acute diarrhea but are seldom used on a chronic basis. A common commercial preparation is Kaopectate. The usual dose is 1.2-1.5 g after each loose bowel movement (maximum 9 g/d). Kaolin-pectin formulations are not absorbed and have no significant side effects except constipation. They should not be taken within 2 hours of other medications (to which they may bind). 

Keywords Chemical weapons Bacteria Toxins Agroterrorism Biosurveillance Preparedness Biological warfare Biocontainment Decontamination... 

Food- and water-borne illnesses may be caused by toxins created by growing bacteria toxins produced by the harmful algal species or contamination of food and/or water with certain bacteria, viruses or parasites. Many cases of food poisoning happen when someone eats food that has harmful bacteria in it. The bacteria or the toxins produced by them can then make the person sick. Bacteria also can get into the water supply and make someone sick. 

Depending on the experimental design, the number of Abs involved in the immunocomplex formation reaction is varying. A t-Ag, like a bacteria toxin, can be directly immobilized on a reaction substrate and can be quantified with a labeled detection antibody (d-Ab) in a direct immunoassay, involving a single t5q)e of Ab. This technique is however limited, since t-Ags for direct surface immobilization have to be available. A more flexible technique, called sandwich immunoassay, consists to flank the t-Ag to be detected between a capture antibody (c-Ab) linked to a reaction substrate and a labeled d-Ab (see Fig. 3b). In this technique, the t-Ag is specific for both c-Ab and d-Ab. Also an enzyme can be used to label the d-Ab, and, in... 

Staphylococcal a-hemolysin is another widely studied pore-forming toxin. It is used by infectious bacteria to perforate host animal cells by a mechanism that is distinct from that of gramicidin. Several aspects of the stmcture and function of this heptameric protein complex have been smdied. 

Proper refrigeration prevents the growth of some microorganisms, such as Salmonella and the production of toxins, such as Staphylococcus aureus. The growth of bacteria Tscherichia coli and Bacillus cereus is substantially checked by proper cooling and handling of milk. Table 14 Hsts diseases transmitted by cows to humans. Pasteurization is the best means of prevention. 

Membrane filtration has been used in the laboratory for over a century. The earliest membranes were homogeneous stmctures of purified coUagen or 2ein. The first synthetic membranes were nitrocellulose (collodion) cast from ether in the 1850s. By the early 1900s, standard graded nitrocellulose membranes were commercially available (1). Their utihty was limited to laboratory research because of low transport rates and susceptibiUty to internal plugging. They did, however, serve a useflil role in the separation and purification of coUoids, proteins, blood sera, enzymes, toxins, bacteria, and vimses (2). 

Endotoxin A toxin produced by bacteria. The toxin is present in the environment only after death of the bacteria. 

Platelet activating factor (PAF) was first identified by its ability (at low levels) to cause platelet aggregation and dilation of blood vessels, but it is now known to be a potent mediator in inflammation, allergic responses, and shock. PAF effects are observed at tissue concentrations as low as 10 M. PAF causes a dramatic inflammation of air passages and induces asthma-like symptoms in laboratory animals. Toxic-shock syndrome occurs when fragments of destroyed bacteria act as toxins and induce the synthesis of PAF. This results in a drop in blood pressure and a reduced... 

I refer, of course, to the toxins produced by phytopathogenic fungi and bacteria. Considering the widespread damage which they cause, it is remarkable that so little is known about the chemistry of these substances. Perhaps the first toxin to receive detailed chemical examination was lycomarasmin (XIX) (36), an isolate from... 

Saxitoxin (STX) is a toxin which is found in marine microorganisms. It is most likely synthesized by bacteria which live in symbiosis with dinoflagellates, a component of phytoplankton. Through the marine food chain, it can lead to poisoning of humans. The mechanism of toxicity of saxitoxin is vety similar to that of tetrodotoxin. Saxitoxin binds from the outside of the membrane to various forms of voltage-sensitive Na+channels and blocks the channel in an activation state-independent manner. 

Septicemia is generally a serious illness caused by the presence of bacteria and/or bacterial toxins in the blood (blood poisoning). 

The most ingenious exocytosis toxins, however, come from the anaerobic bacteria Clostridium botulinum and Clostridium tetani. The former produces the seven botulinum neurotoxins (BoNTs) A-G the latter produces tetanus neurotoxin (TeNT). All eight toxins consist of a heavy (H) chain and a light (L) chain that are associated by an interchain S-S bond. The L-chains enter the cytosol of axon terminals. Importantly, BoNT L-chains mainly enter peripheral cholinergic terminals, whereas the TeNT L-chain mainly enters cerebral and spinal cord GABAergic and glycinergic terminals. The L-chains are the active domains of the toxins. They are zinc-endopeptidases and specifically split the three core proteins of exocytosis, i.e. the SNAREs (Fig. 1 inset). Each ofthe eight toxins splits a... 

Tetrodotoxin (TTX) is a toxin derived from bacteria which is concentrated in the gonads and liver of certain pufferfishes (fugu). Similar to saxitoxin, tetrodotoxin is a very potent blocker of most voltage-sensitive Na+ channels. 

A toxin is a poisonous substance produced by some bacteria, such as Clostridium tetani, the bacteria that cause tetanus. A toxin is capable of stimulating the body to produce antitoxins, which are substances that act in the same manner as antibodies. Toxins are powerful substances, and like other antigens, they can be attenuated. A toxin that is attenuated (or weakened) but still capable of stimulating the formation of antitoxins is called a toxoid. 

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