These strains are present in a wide range of agricultural commodities associated with tropic and subtropic zones. These commodities include species of peanuts and corn.
The most potent toxin is AFB1 and it is associated with carcinogenic effects. Ochratoxin is a type of toxin produced by both Penicillium and Aspergillus species.
Ochratoxins are further classified in types A, B and C and differ in structure. Ochratoxins have demonstrated carcinogenic properties and are often found in beverages such as beer and wine, as the fungal species which produce ochratoxins are often found on the plants used to produce these products.
Citrinin is a mycotoxin that has been isolated in numerous species of both Penicillium and Aspergillus. Many of these fungal species are utilized in food processing and are often found in foods including cheese, wheat, rice, corn, and soy sauce. Citrinin is known to function as a nephrotoxin, indicating it has toxic effects on kidney function. Ergot Alkaloids are specific compounds that are produced as toxic alkaloids in Claviceps , a group of fungi associated with grasses, rye, and related plants.
The disease caused by ingestion of this fungi is called ergotism. Ergotism is characterized by detrimental effects on the vascular system in particular, including vasoconstriction of blood vessels resulting in gangrene, and eventually, limb loss if left untreated. Additionally, ergotism can present as hallucinations and convulsions as ergot alkaloids target the central nervous system. Due to the vascular system effects of ergot alkaloids, they have been used for medicinal purposes.
Learning Objectives Describe the major toxin types bacterial toxins and mycotoxins and their mechanisms of action. Bacterial Toxins Bacterial toxins are typically classified under two major categories: exotoxins or endotoxins. In the case of the botulinum neurotoxin BoNT , it is known to be of use in the treatment of muscle atrophies, mainly in facial paralysis, muscular hyperactivity, and dystonias.
The BoNT has also been used to prevent facial wrinkles. However, it was found to have a preventive effect on headaches, as it is able to lessen it in some diseases such as neuropathic pain, low back pain, myofascial pain, and bladder pain. Studies supporting this statement have been carried out with studies based on human pain, these studies have shown positive and negative results. They are double-blind studies with placebo control.
The positive action of the Botulinum toxin BTX has been characterized when administered to cells previously exposed to cigarette smoke; this suggests that it is a preventive agent to reduce the risk of necrosis in the respiratory tissue of patients who smoke [ — ]. Another notable example of toxin research is the use of toxins for medical treatments. For example, in studies by Lai et al.
This is an advantage that can be used to create drugs paired with the attenuated toxin or to a part of it, so that it can be able to reach the nucleus, be separated from the drug, and act as therapy against cancer, without the toxin causing any damage. Several in vivo and in vitro studies will be needed to establish it as an alternative cancer therapy [ ].
The mechanisms that develop in the pathway that creates the pore have been revealed in the study of pore-forming toxins PFT in the cell membrane. Nowadays, the mechanism of formation is almost completely known stage by stage.
The challenge in the research is to know the process in detail and, from that, design therapies with antibodies, drugs, or other compounds that can inhibit its effects to know how the cell senses the presence of the pore, if it is at a concentration level of ions or by cytoplasmic signals, allowing it to run repair mechanisms of membrane damage [ ].
An interesting group of toxins are the immunotoxins, which are formed by a portion of antibody and a portion of toxin; the toxin has an intracellular action to kill the target cells. Most immunotoxins are designed to attack cancer cells; therefore, they are alternative to chemotherapy. The regulation of immunological signals and the treatment against viral and parasite infections are also applications of immunotoxins.
Nevertheless, studies should focus on the methods for obtaining the toxin-antibody compounds, because molecular cloning to obtain a hybrid immunotoxin has not been efficient. Therefore, the methods for obtaining and purifying must be improved.
The recent results are the creation of smaller immunotoxins with less immunogenicity, leaving only the site of action with the membrane, or the immunogenic site allowing its insertion into the target cell. Related studies are based on the creation and purification of monoclonal antibodies against toxins; for example, the use of an optimized anti-Alpha-toxin antibody of S.
This study showed a decrease in the number of bacteria in lungs and kidneys of the evaluated mice; mice showed minimal swelling and intact lung tissue. Thus, the mice had a higher percentage of survival, even with the combined treatment of the anti-Alpha-toxin antibody plus vancomycin or linezolid [ 95 , ]. Another alternative is the use of chemicals that inhibit the effect of bacterial toxins. Due to the importance of toxins in the food area, with clinical and pathological consequences, these mechanisms of action and the nature of toxins should be thoroughly investigated, in order to design strategies to prevent and manage effectively toxicoinfections [ ].
It should be of particular attention, the use of toxins as an alternative treatment that allows to have tools for treating diseases such as cancer, the use of immunotoxins and pharmacotoxins. Governments should raise food safety as a public health priority, by establishing effective food safety systems to ensure that food producers and suppliers, throughout the food chain, act responsibly and provide safe food to consumers. Food contamination can occur at any stage of the manufacturing or distribution process, although the responsibility lies primarily with the producers.
Nevertheless, a large part of the foodborne diseases are caused by food that has been improperly prepared or handled at home, in food establishments, or in street markets.
It is a joint responsibility for consumers, traders, and governments to work together to implement regulations, enforce laws that support, increase, and sustain food safety. The authors are also grateful to Sofia Mulia for her help in preparing the English version of the manuscript of the chapter.
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Built by scientists, for scientists. Our readership spans scientists, professors, researchers, librarians, and students, as well as business professionals. Downloaded: Abstract In the environment, there are polluting substances that can cause adverse reactions in human beings when entering the body through different ways ingestion, inhalation, injection, or absorption.
Keywords toxins bacteria food poisoning food-borne disease. Introduction The main pollutants can be poisons, chemical compounds, toxic gases, and bacterial toxins. Types of bacterial toxins A bacterial toxin is a macromolecule mainly of protein origin, which can cause toxic damage in a specific organ of the host [ 5 ].
Toxins can be divided in endotoxins and exotoxins: Endotoxins or lipopolysaccharides LPS : These are the components of the outer membrane of the Gram-negative bacteria; they are considered the most important antigen of the bacteria; they are released into the medium after different processes such as lysis and cell division. LPS are formed by three regions [ 7 ]: Lipid A is a glycolipid formed by a disaccharide glucosamine bound to fatty acids, that are usually capric, lauric, myristic, palmitic, and stearic acids, which are inserted in the outer membrane of the bacterium.
The nucleus a heteropolysaccharide derived from hexoses and heptoses. Lipid A and the nucleus are bound by the sugar acid 2-ketodeoxyoctanate KDO.
Depending on their mechanism of action, exotoxins are divided as follows: Toxins Type I. Toxin type Definition Enterotoxin It produces a net secretion in ligated intestinal segments without histological evidence of intestinal lesion or damage to nonerythrocytic cells in in vitro tests. It stimulates the increase in the short circuit current Isc and the potential difference PD in the using chamber without evidence of intestinal damage; this result involves the secretion of active electrogenic anions.
Additionally, a toxin can impair electrically neutral NaCl absorption, which also results in a net secretion of ions. Cytoskeleton-altering toxin It alters the cellular form and has been frequently shown to be caused by the F-actin rearrangement. The toxin can cause limited cell damage but is not lethal, and it may or may not be associated with the evidence of net secretion in in vivo or in vitro disease models in intestinal epithelial cells.
Cytotoxin It causes cell or tissue damage, usually ending with cell death. The toxin may or may not be associated with net secretion in in vivo or in vitro disease models in intestinal epithelial cells. Neurotoxins It involves the release of one or more neurotransmitters from the enteric nervous system.
It alters the activity of smooth muscle in the intestine. Table 1. Classification of enteric toxins. Epidemiology The high population growth and the food marketing, have generated pathogens causing FBDs to be quickly transported, this has produced outbreaks in different regions, affecting the morbidity, mortality, and economy of the population involved.
Intrinsic parameters Intrinsic factors affecting the proliferation rate are more related to the internal characteristics of food products, and the way in which these characteristics maintain or affect the growth of microorganisms; these factors include water activity, pH, oxidation-reduction potential, content and type of nutrients, inhibiting substances, and biological structures [ 44 , 45 ].
Water activity It is defined as the amount of water available for the growth of microorganisms; microbial proliferation decreases when water availability also decreases. Content of nutrients Microorganisms have nutritional requirements, most of them need external sources of nitrogen, energy, minerals, as well as vitamins, and related growth factors; these requirements are found in our food, so if they have the right conditions to develop, they will.
Extrinsic parameters Food factors are very important for the development of microorganisms; there are external or extrinsic factors.
Storage temperature Microorganisms have an optimal range, as well as a minimum and maximum temperature to grow. Oxygen availability and presence of other gases in the environment Like temperature, the oxygen availability determines the microorganisms that will be active. Relative humidity in the environment Relative humidity RH of the environment is important from the point of view of water activity within food and the growth of microorganisms on surfaces.
Presence and activities of other microorganisms Some food origin organisms produce substances that can inhibit or be lethal for other organisms; these include antibiotics, bacteriocins, hydrogen peroxide, and organic acids. Undercooked pork, beef and poultry, contaminated eggs, and milk.
Salmonella spp. Salmonellosis Salmonella Typhimurium, Salmonella Enteritidis. Undercooked poultry, cauliflowers, and tomatoes. Vibrio vulnificus Septicemia in people with underlying diseases or people who are taking immunosuppressive drugs or steroids.
Seafood, usually oysters. Mycobacterium bovis Cervical lymphadenopathy, intestinal lesions, chronic cutaneous tuberculosis. Contaminated milk. Pasteurized milk. Listeria monocytogenes Meningitis, encephalitis, sepsis in pregnant women, intrauterine or cervical infection that can lead to miscarriage or birth of a dead child. Raw beef, pork, poultry, vegetables and milk, cheese, ice cream, smoked fish, and raw fish.
Table 2. Pathogens that cause infection. Mixture of oil and nonacid garlic, potatoes cooked at high temperatures, and stews. Bacillus cereus Fried rice syndrome. Rice cooked at high temperatures, sauces, soups, and puddings. Staphylococcus aureus Toxic shock syndrome.
Meat and meat products cooked at high temperatures, poultry, and salads with mayonnaise. Table 3. Pathogens that cause intoxication. Hamburgers, nonpasteurized milk, contaminated water, spinach, and lettuce. Shigella spp. Hemolytic Uremic Syndrome.
Salads, lettuce, raw vegetables, and milk. Aeromonas spp. Meningitis, peritonitis, myocarditis, hemolytic uremic syndrome, necrotizing fasciitis in wounds.
Meat beef, sheep, pork and chicken , vegetables, eggs, fish, seafood, and prepared food. Cronobacter sakazakii Permanent neurological or developmental deficits; death.
Powdered infant formula. Vibrio parahaemolyticus Gastroenteritis, septicemia and wound infection. Severe infections in immunocompromised people. Raw or undercooked seafood, usually oysters. Clostridium perfringens Clostridial necrotizing enteritis. Meat juice, stews, cooked beans, meat cooked at high temperatures. Campylobacter spp. Cheese made with raw milk and chicken meat. Nonpasteurized milk, tofu, nonchlorinated water, undercooked meat, oysters and fish.
Vibrio cholerae serogroup O1 or serogroup O Cholera. Contaminated water and raw seafood. Vibrio cholerae serogroup no-O1 Less severe than Cholera; gastrointestinal infections, sepsis. Raw, semicooked or recontaminated fish and shellfish after cooking. Table 4. Pathogens that cause toxico-infection. Name Biological effect Cholera toxin Ctx A-5B It activates the adenylyl cyclase; increases the levels of intracellular cAMP promoting fluid and electrolytes secretion in the intestinal epithelium, causing diarrhea.
It is a potent exotoxin. It promotes water and electrolytes secretion from the intestinal epithelium by causing diarrhea. Shiga toxin A-5B Inactivates the ribosomal subunit 60S and inhibits protein synthesis causing the death of susceptible cells.
It inhibits the presynaptic release of acetylcholine from peripheral cholinergic neurons, resulting in flaccid paralysis. The neurotoxin exists in seven different serotypes A-G. CPE enterotoxin Lethal, cytotoxic and enterotoxic activity. Stimulates the adenylyl cyclase allowing the increase of cAMP in epithelial cells, which causes diarrhea. Alpha-toxin It produces gas gangrene. It has phospholipase PLC , sphingomyelinase, hemolytic, and dermonecrotic activities.
The mature protein is organized into two domains; the amino-terminal, which contains the PLC activity, and the carboxyl-terminal binding that depends on calcium. Depending on the lipid composition of the cell membrane, the Alpha-toxin may be hemolytic in the presence of calcium. Beta-toxin It forms selective pores for monovalent cations in lipid bilayers and sensitive cells membranes, so it functions as a neurotoxin capable of producing arterial constriction.
Epsilon-toxin Produced and secreted by a prototoxin that, when it suffers a specific proteolytic cleavage, it acquires its maximum biological activity. Activation can be catalyzed by proteases such as trypsin, chymotrypsin, and a zinc-dependent metalloproteinase.
Iota-toxin It has dermonecrotic, cytotoxic, enterotoxic activities, and it causes intestinal histopathological damage. This toxin is binary and consists of a binding peptide Ib and an enzymatic peptide ADP-ribosyltransferase Ia. The first one is necessary to internalize the second one.
The Iota-toxin is generally activated by the effect of the proteases present in the intestinal tract. The deamination of the glutamine residue at position 63 of Rho to a glutamic acid produces a dominant-active Rho protein incapable of hydrolyzing the GTP, resulting in cellular necrosis and bloody diarrhea associated with colitis.
Staphylococcal enterotoxins are superantigens that cause massive activation of the immune system, including lymphocytes and macrophages; the exact role in emesis is not known.
Cereulide Thermostable peptide, toxic for the mitochondria when acting as a potassium ionophore. HBL, NHE, Citotoxin K or CytK HBL is a three-component hemolysin; two protein subunits, L2 and L1 cytolytic components , and a B protein favors binding to the host cell , apart from the hemolytic effect, it is cytotoxic, dermonecrotic and causes vascular permeability. Both toxins are organized into operons hbl and nhe , where the genes encoded the NHE components are transcribed together. CytK forms pores in the epithelial cells membrane, and it has necrotizing and cytotoxic activity.
Table 5. Foodborne diseases caused by bacterial toxins This section will be addressed to some diseases caused by consuming food contaminated with bacterial toxins or microorganisms that produce them. Vibrio cholerae V. Staphylococcus aureus Staphylococcal foodborne illness is one of the most common diseases acquired by S. Bacillus cereus B.
Clostridium perfringens C. Clostridium botulinum C. Listeria monocytogenes L. More Print chapter. How to cite and reference Link to this chapter Copy to clipboard. Available from:. Over 21, IntechOpen readers like this topic Help us write another book on this subject and reach those readers Suggest a book topic Books open for submissions. More statistics for editors and authors Login to your personal dashboard for more detailed statistics on your publications. Access personal reporting.
More About Us. It produces a net secretion in ligated intestinal segments without histological evidence of intestinal lesion or damage to nonerythrocytic cells in in vitro tests. It alters the cellular form and has been frequently shown to be caused by the F-actin rearrangement. It causes cell or tissue damage, usually ending with cell death. It involves the release of one or more neurotransmitters from the enteric nervous system. Salmonella enterica serovar Typhi and Salmonella enterica serovar Paratyphi.
Vibrio vulnificus. Septicemia in people with underlying diseases or people who are taking immunosuppressive drugs or steroids. Mycobacterium bovis. Mycobacterium avium, subspecies paratuberculosis. Listeria monocytogenes. Meningitis, encephalitis, sepsis in pregnant women, intrauterine or cervical infection that can lead to miscarriage or birth of a dead child.
Clostridium botulinum. Bacillus cereus. Staphylococcus aureus. Escherichia coli OH7. Hemorrhagic colitis, Hemolytic uremic syndrome in children. Cronobacter sakazakii. Vibrio parahaemolyticus.
Gastroenteritis, septicemia and wound infection. Clostridium perfringens. Yersinia enterocolitica. Vibrio cholerae serogroup O1 or serogroup O Vibrio cholerae serogroup no-O1. It activates the adenylyl cyclase; increases the levels of intracellular cAMP promoting fluid and electrolytes secretion in the intestinal epithelium, causing diarrhea. The binding of ST to the guanylyl cyclase receptor results in an increase of cyclic GMP, affecting the flow of electrolytes.
Inactivates the ribosomal subunit 60S and inhibits protein synthesis causing the death of susceptible cells. It is a neurotoxin consisting of a heavy and a light chain linked by a disulfide bond.
Lethal, cytotoxic and enterotoxic activity. It produces gas gangrene. It forms selective pores for monovalent cations in lipid bilayers and sensitive cells membranes, so it functions as a neurotoxin capable of producing arterial constriction.
Produced and secreted by a prototoxin that, when it suffers a specific proteolytic cleavage, it acquires its maximum biological activity. It has dermonecrotic, cytotoxic, enterotoxic activities, and it causes intestinal histopathological damage. It modifies the Rho, a subfamily of GTP-binding proteins that regulate cytoskeletal actin. Search Menu. Article Navigation. Close mobile search navigation Article Navigation. Volume Article Contents Abstract. Mechanisms of Microbial Diarrhea.
Cholera and E. New Approaches to Diagnosis and Therapy. How Intestinal Bacteria Cause Disease. Guerrant , Richard L. Reprints or correspondence: Dr. Oxford Academic. Ted S. Aldo A. David A. Cite Cite Richard L. Select Format Select format. Permissions Icon Permissions. Abstract An improved understanding of how intestinal bacteria cause disease has become increasingly important because of the emergence of new enteric pathogens, increasing threats of drug resistance, and a growing awareness of their importance in malnutrition and diarrhea.
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