Bacterial toxins are disease-producing organisms or rather parasites that live off animals and plants. Although there are only a very few amount of species that actually cause diseases, they can be very dangerous and life threatening to their hosts. “A small amount of bacteria are pathogens (disease producing organisms).”(Purves et al., 2001, p. 467) “To be a disease-producing (pathogen) agent, the bacterium must be able to penetrate the organism, to reproduce, and to cause injury to the tissues.” (Core et al., 1961, p.309) “These diseases are caused by microbial agents.”(Purves et al., 2001, p. 467)
Bacterial Toxins generally are placed into two different categories called Endotoxins and Exotoxins.(Purves et al., 2001, p. 467) “Endotoxins are generally not fatal however can cause fever, vomiting, and diarrhea.” (Purves et al., 2001, p. 467) “These toxins are lipopolysaccharides that form part of the outer bacterial membrane.” (Purves et al., 2001, p. 467) The second category, exotoxins are proteins released by living, multiplying bacteria, and they may travel throughout the host’s body. (Purves et al., 2001, p. 467) These on the other hand are highly toxic and often fatal but do not cause symptoms such as endotoxins. (Purves et al., 2001, p. 467)
During the Nine-tenth Century, a man named Robert Koch set up a set of four rules in which an organism can cause certain disease, even though at this time the thought of microorganisms were not common. (Purves et al., 2001, p. 467) First of all, “the microorganism must always be found in individuals with the disease. Secondly, the microorganism can be taken from the host and grown in pure culture. Thirdly, A sample of the culture produces the disease when injected into a new, healthy host. And finally, the newly infected host yields a new, pure culture of microorganisms identical to those obtained in the second step.” (Purves et al., 2001, p. 467) Through Natural Selection, the parasite finds the most suitable host to live off from. (Waley et al.,1964, p. 367-368) The severity of the disease mainly depends on a variety of variables. These variables are age, sex, race, and the percentage of the bacteria available in one place. (Goodnight et al., 1962, p.136) This means that some hosts can resist the bacteria whereas others do not have the antibodies to resist them.(Waley et al., 1964, p.367) For example, a geriatric dog may be more susceptible to a disease than a puppy because its anti-bodies are less efficient than the puppies’ anti-bodies that are acquired from the bitch.
A subtopic in this category would be the health of the species. A healthier animal will catch a bacterial toxin more easily than a sick animal. For example, a geriatric human is more susceptible to pneumonia than a younger human. Secondly, the sex of the animal may determine what type of bacterial toxin is susceptible to the disease. For example, female humans may get vaginitis (better known as “feminine itch”) however a man can not attain this bacterial toxin. Thirdly, race can determine which bacterial toxin is susceptible for which animal. A good example for race would be that dogs are more susceptible to catching bacterial toxins that cause ear infections that a feline. Some organisms may not even have the right type of physiological properties to host the parasite, which are available by heredity.(Waley et al., 1964, p. 367) “An organism is more likely to acquire an infection if the number of organisms he encounters is very large. (Goodnight et al., 1962, p. 134) For example, “A single cough from a person with pneumonia may contain million of bacteria. (Goodnight et al., 1962, p. 135)
The ability of the parasite to infect the host is determined by “the virulence of the strain, the portal of entry, and the number of parasites present.”(Goodnight et al., 1962, p.134) In addition, for “the bacterial organism to be a successful pathogen, it must arrive at the body surface of a potential host, enter the host body, evade the host defenses, multiply inside the host, and infect a new host.” (Purves et al., 2001, p. 467) However, it is important to know that the resistance of the host determines if the pathogen is successful or not. Once a pathogen has become successful and has invaded the animal, it will set up an infection. These infections simply may make the animal create a lesion or in more serious cases, a general systemic infection may occur.(Waley et al., 1964, p.368) “Most virulent bacteria produce one or more enzymes that are destructive to the tissues of the host. These include: the hemolysins (which cause the lysis or breakdown of red blood cells), coagluase (which induces blood clotting and thus lays down a barrier of fibrin around lesions, presumably blocking out the leucocytes), hyaluranidase (which makes the thickening material in connective tissue more liquid, permitting the invading organism to spread more easily), and proteinases (which cause lesions by breaking down tissue cells).” (Waley, et al., 1964, p.368)
Animals may resist the parasite however by anti-bodies and the environment around the animal. “The three main lines of defense against disease are: the outer skin, the inner cellular response, and immunity mechanism.” (Goodnight, et al., 1962, p. 136) An animal can however build resistance (immunity) to the pathogen. This is done by two methods. These two methods are for the possible host to build its own anti-body or to go for preventative treatment. (Goodnight et al., 1962, p.138) For young animals an anti-body may be handed down from the mother or can be naturally built up. Exercise and eating healthy helps in the aid of building anti-bodies. For example, a person that exercises weekly is less susceptible to a pathogen than a person who is less active. Preventative treatment would include taking vitamins and regularly getting immunizations. Most animals and humans are required to get injections of immunizations at an early age to start the process of building anti-bodies that resist air-born pathogens.
A good example of an endotoxin infection in a dog would be the start of tooth decay. Tooth decay begins when saliva and food that gathers in between the teeth and under the gums of the dogs mouth which causes plaque to form. If not removed within a timely manor, packets of yellow or brown pus may soon start to appear (on some animals this does not occur at all). This separates the teeth of the dog even further and creates more space for food and bacteria to accumulate. This is what causes gingivitis and periodontal diseases. Although gingivitis is reversible, periodontal is a disease and can not be reversed. Periodontal disease can create inflamed gums and can cause bleeding. If not corrected by a veterinarian, the teeth will begin to fall out or hang there and cause stress on the dog. In most cases, the dog will become very irritated and may start biting the owner or whoever comes in close vicinity. In a short period of time, the dog will also stop eating and will in turn begin to lose weight. Again, if the dog is not taken to the veterinarian to get antibiotics, as stated above, lesions can begin to form. In later years, heart, liver, and lung diseases will occur because the bacterium spreads throughout the body. At this time, the anti-bodies of the dog are decreasing and what fighting anti-bodies are still available in the dog, will soon become less powerful than the pathogen and lose the war.
An example of exotoxins is discovered when a dog begins to have coughing attacks. In the most serious situation, this may mean that the dog has a sort of bacterial infection in the lungs. This can also be treated by medications and antibiotics. In some cases however if the condition does persist to infect the lungs of the dog, daily prescription medications will be needed for the life span of the dog. In this situation, the life-span of the dog is usually decreased by fifty percent. Therefore it is very fatal if not taken care of immediately.
In conclusion, bacteria toxins either exotoxins or endotoxins are dangerous to the health of animals and plants. The variables of being susceptible to catching pathogens are determinate upon age, sex, race, health of the host, and the percentage of available bacteria in the environment of the host. The ways we can fight off these pathogens are by building ones own anti-bodies and/or keeping up on immunizations. Although bacteria may cause harm to a human or plant, it is amazing that humans have created ways in which to apply bacterial toxins for daily use such as the “production of cheese, sewage treatment, and the industrial production of an amazing variety of antibiotics, vitamins, organic solvent, and other chemicals.” (Purves et al., 2001, p. 467)
Core, E.L., P.D. Strausbaugh, B.R. Weimer 1961 John Wiley and Sons, INC., New York, 309
Goodnight, C.J., M. L. Goodnight, R.R. Armacost 1962 John Wiley and Sons, INC., New York, 134-128
Purves, W.K., G.H. Orians, H.C. Heller, and D. Sadava 2001
Life, The Science of Biology, 6th edition Sinauer, Sunderland, Massachusetts, 466-467 pp
Waley, W.C., Breland, C. Heimsch, A. Phelps, A.R. Schnank, O.Wyss 1964
Principles of Biology, 3rd edition Harper and Row Publishers, INC. New York, 367-368