this tool is able to adsorb toxins generated by microalgae or cyanobacteria, known as cyanotoxins. the adsorption is passive, and the biotoxins adhere to porous, resin filled sachets, or spatt bags where they are then physically removed and examined. spatt is a useful tool in tracking algal blooms as it is reliable, sensitive, and inexpensive. it has the ability to quickly alert the existence of aquatic toxins which prevents it from bioaccumulating in marine life. one of the downsides is that it does not give very good results for water-soluble toxins as compared to hydrophobic compounds. this tool is mainly used to determine intercellular concentrations of toxins but the cyanobacteria can also be lysed to determine the total toxin amount in a sample. other drawbacks, such as a lack in calibration and the ability to only monitor dissolved toxins, make it difficult for this tool to be implemented in a more widespread manner. however, spatt devices are able to detect many lipophilic and hydrophilic toxins that are linked to harmful algal bloom. polymerase chain reaction (pcr) pcr is a molecular tool that allows for analysis of genetic information. pcr is used to amplify the amount of certain dna within a sample which are usually specific genes within a sample. genetic targets for cyanobacteria in pcr include the 16s ribosomal rna gene, phycocyanin operon, internal transcribed spacer region, and the rna polymerase β subunit gene. pcr is effective when the gene of a known enzyme for producing the microbial toxin or the microbial toxin itself is known. one type of pcr is real time pcr also called quantitative pcr. this type of pcr uses fluorescence and then does an analysis by measuring the amount of fluorescence that reflects the dna sample more specifically nucleic acids at specific times. another type of pcr is digital pcr that looks at nucleic acid quantifications. digital pcr uses dilutions and samples from microlitre reactions to achieve a more accurate quantification of nucleic acids. this type offers a more linear analysis by looking at the positive and negative reactions. both pcr's are beneficial but there are advantages and disadvantages for both. the digital pcr has several advantages over real time pcr which includes no standard curve, more precise, less affected by simple inhibitors. digital also has disadvantages to real time which is limited reaction mixture time, more complex and high risk of contamination. enzyme inhibition there are many diverse ways of monitoring enzyme levels through the use of enzyme inhibition. the general principle in many of these is the use the knowledge that many enzymes are driven by phosphate-releasing compounds such as adenosine triphosphate. using radiolabelled 32p phosphate a fluorometric analysis can be used. or unique polymers can be used to immobilize enzymes and act in an electrochemical biosensor. overall, the benefits include a fast response time and little sample preparation. some of the downsides include a lack of specificity in terms of being able to get readings of very small amounts of toxin and the rigidity of the assays in apply certain procedures to different toxins. immunochemical methods this detection method uses mammalian antibodies to bind to microbial toxins which can then be processed in a variety of different ways. of the commercial ways of using immunochemical detection would be enzyme-linked immunosorbent assays (elisa). this assay has the advantage of being able to screen for a broad range of toxins but could have issues with specificity depending on the antibody used. a more exotic setup involves the use of cds quantum dots which are used in an electro-chemiluminescent immunosensor. a major aspect of immunochemical methods being tested in laboratories are uses of nanowires and other nanomaterials to detect microbial toxins. tetrodotoxins these toxins are produced by vibrio species of bacteria and like to accumulate in marine life such as the pufferfish. these toxins are produced when vibrio bacteria are stressed by changes in temperature and salinity of environment which leads towards production of toxins. the main hazard towards humans is during consumption of contaminated seafood. tetrodotoxin poisoning is becoming common in more northern and typically colder marine waters as higher precipitation and warmer waters from climate change triggers vibrio bacteria to produce toxins. most of the marine life that produce this toxin are typically found in warm water for example the red sea and the mediterranean sea. for example, pufferfish do produce this toxin, some pufferfish, such as takifugu v., produce tetrodotoxin in their skin glands. another organism that releases the tetrodotoxin from their skin are blue-ringed octopuses (hapalochlaena fasciata). the natica lineata snails produce the tetrodotoxin and store it in the muscle. the snail releases the toxin by absorbing water into the muscle cavity and it is released when the snail is attacked. once a human consumes the toxin, the individual could experience mild symptoms such as paresthesias of the lips or tongue, vomiting and headaches. the individual could also experience severe symptoms such as respiratory or heart failure. at this time there is no treatment for tetrodotoxin poisoning other than respiratory support. viral toxin rotavirus nsp4 there is only one viral toxin that has been described so far: nsp4 from rotavirus. it inhibits the microtubule-mediated secretory pathway and alters cytoskeleton organization in polarized epithelial cells. it has been identified as the viral enterotoxin based on the observation that the protein caused diarrhea when administered intraperitoneally or intra-ileally in infant mice in an age-dependent manner. nsp4 can induce aqueous secretion in the gastrointestinal tract of neonatal mice through activation of an age- and ca2+-dependent plasma membrane anion permeability. virus involvement in toxigenicity several bacteriophages contain toxin genes that become incorporated into the host bacteria genome through infection and render the bacteria toxic. many well known bacterial toxins are produced from specific strains of the bacteria species that have obtained toxigenicity through lysogenic conversion, pseudolysogeny, or horizontal gene transfer. although these are not viral toxins, researchers remain extremely interested in the role phages play bacterial toxins due to their contribution to pathogenesis (toxigenesis), virulence, transmissibility and general evolution of bacteria. examples of toxins encoded by phage genes: cholera toxins: encoded by ctx phages, virulent vibrio cholerae strains require lysogenic conversion by ctx phage infection several botulinum toxins (bonts): type c and d bonts have been shown to be encoded by clostridial phages and are produced by clostridium botulinum strains harboring these phage genes shiga toxins: encoded by lambdoid phages, mainly produced by lysogenic shiga-toxin producing strains of e. coli (stec) diphtheria toxins: encoded by corynephage ß, produced by lysogenic corynebacterium diphtheriae strains infected with corynephage ß several staphylococci toxins (staphylokinase (sak), staphylococcal enterotoxin a (sea), exfoliative toxin (eta), panton-valentine leucocidin (pvl), and other enterotoxins): toxins that are phage-encoded and produced by lysogenic converted strains of the staphylococci group. mycoviruses some mycoviruses also contain toxin genes expressed by host fungal species upon viral infection. while these toxins are classified as mycotoxins, the role of mycoviruses is also of interest to researchers in terms of fungal virulence. examples include the mycoviruses scv-m1, scv-m2, and scv-m28 in the totiviridae family that contain “killer toxin” genes k1, k2, and k3, respectively. these “killer toxins” are produced by yeast, namely of the saccharomyces cerevisiae species, that destroy neighboring yeast cells. recently, researchers discovered that it is only the yeasts infected with either scv-m1, scv-m2, or scv-m28 mycoviruses that have the ability to produce a “killer toxin.” mycotoxins mycotoxins are secondary metabolites that are constructed by microfungi. mycotoxins can be harmful because they can cause disease and death in humans and animals. they are found in many pharmaceuticals like antibiotics and growth developments. mycotoxins can also play a role in chemical warfare agents, cwa, which are chemicals that contain toxins that are used to cause death, harm, or injuries to individuals that are considered enemies by the military during warfare. mycotoxins are synthesized by different types of moulds and are built by a wide group of toxins. mycotoxins have a low molecular weight compound that is usually less than 1000 grams per mol. there are roughly 400 toxic mycotoxins that are constructed by 100 different fungi species that have been researched. mycotoxins gain access into the body of a human or animal by food, they can contaminate many different types of agriculture during cultivation, harvesting, storage, and areas with high humidity. the food and agriculture organization reported that about 25% of products produced by agriculture contain mycotoxins and this can lead to economic losses in the agricultural community. levels of mycotoxins secretion can rely on varying temperatures, the ideal temperature for mycotoxins to grow is from 20 degrees celsius to 37 degrees celsius. mycotoxin production also relies heavily on water activity, the ideal range would be from 0.83 to 0.9 aw and higher. humidity plays a key in the production of mycotoxins as well. the higher the humidity levels, between 70% to 90%, and moisture levels, 20% to 25%, allow the mycotoxins to grow more rapidly. foods that mycotoxins are found in cereal, spices, and seeds. they can also be found in eggs, milk, and meat from animals that have been contaminated during their feeding process. since they are resistant to high temperatures and physical and chemical reception, it is considered unavoidable while cooking at high temperatures. types trichothecenes is a mycotoxin that is produced from the fungi species, fusarium graminearum. the t-2 toxin, type a, and don, type b, are major mycotoxins that are responsible for toxicity in humans and animals. these two types come from an epoxide at the c12 and c13 positions in the trichothecenes. the t-2 toxin was found after civilians ate wheat that was contaminated by the fusarium fungi, during wwii from a biological weapon, the t-2 toxin was an outbreak and made humans develop symptoms like food poisoning, chills, nausea, dizziness, etc. the trichothecenes mycotoxin affects animals by decreasing plasma glucose, blood cell and leukocyte counts. pathological changes in the liver and stomach, as well as weight loss has been accounted for. zearalenone is a mycotoxin that is produced from fusarium graminearum and fusarium culmorum that are found in different types of foods and feeds. zearalenone is a non-steroidal estrogenic mycotoxin that is found in farm animal's reproductive disorders and in humans it causes hypoestrogenic syndrome. effects that come from zearalenone include, enlarged uterus, improperly running reproductive tract, decreasing the fertility in women, and causes progesterone and estradiol levels to become not normal. if zearalenone is consumed during pregnancy, it can cause reduced fetal weight and decrease the chance of survival for the embryo. fumonisins, fusarium verticillioides, is found in nature where fumonisin b1 has largely contaminated the area. these mycotoxins are hydrophilic compounds. studies have shown that esophageal cancer can be related back to corn grain that contains fumonisins. other effects from fumonisins are birth defects of the brain, spine, and spinal cord. in animals, problems with the pulmonary edema and hydrothorax swine's have been proven to have association with fumonisins. ochratoxin is a mycotoxin that is produced by aspergillus species and penicillium species. the most researched ochratoxin is the ochratoxin a (ota), which is a fungal toxin. this mycotoxin targets the ota of kidneys and causes kidney disease in humans. ochratoxin a is an immunosuppressive compound. ochratoxin is a renal carcinogen, which has been found by animals containing ota. aflatoxin is a mycotoxin that is produced from aspergillus flavus and aspergillus parasititcus. a type of aflatoxin, afb1 is the most common mycotoxin that is found in human food and animal feed. afb1 targets the liver of both humans and animals. acute aflatoxicosis can make humans and animals have symptoms like abdominal pain, vomiting, and even death.