Protozoa

Protozoa, such as Cyclospora cayetanensis, and also various foodborne trem-atodes have been associated with infections, often with severe, chronic, or fatal health consequences (Molins, Motarjemi, and Kaferstein, 2001). 

Safety of industrial lactic acid bacteria. Journal of Biotechnology 68 171-178. 

Aguirre, M. and Collins, M.D. 1993. Lactic acid bacteria and human clinical infection. Journal of Applied Microbiology 75 95-107. 

Allende, A., Martinez, B., Selma, V., Gil, M.I., Suarez, J.E., and Rodriguez, A. 2007. Growth and bacteriocin production by lactic acid bacteria in vegetable broth and their effectiveness at reducing Listeria monocytogenes in vitro and in fresh-cut lettuce. Food Microbiology 24 759-766. 

Arroyo, M., Aldred, D., and Magan, N. 2005. Environmental factors and weak organic acid interactions have differential effects on control of growth and ochratoxin A production by Penicillium verrucosum isolates in bread. International Journal of Food Microbiology 98 223-231. 

Protozoa are microscopic single cell organisms, some of which can infect and cause disease in humans. 

Pathogenic protozoa are able to evade the host s immune system by invading host cells. Examples of infections with protozoa include malaria, amoebiasis, leishmaniasis, trypanosomiasis and toxoplasmosis. Most of these infections tend to occur in countries of the developing world rather than in the United Kingdom. Nevertheless, occasional cases of them are seen in people arriving back from abroad. 

The most severe form of malaria is caused by Plasmodium falciparum and can be fatal. Fever occurs every third day due to rupture of infected red blood cells. Other forms are less severe and rarely fatal. 

Toxoplasmosis is common in the United Kingdom and in most cases causes a mild influenza-like illness, although infection during pregnancy can be a cause of abortion or neurological damage in the foetus. In patients with HIV, toxoplasma can be the cause of serious illness. Toxoplasma encephalitis is a common complication of HIV infection. 

Protozoa pathogenic to man which can be transmitted by contaminated water (Entamoeba histolytica, Giardia lamblia, Naegleria gruberi and Acan-thamoeba) are described in Section 4.2.7. 

When the protozoan Tetrahymena pyriformis is grown in the presence of 

Although in modem systematics the taxon Protozoa is no longer existent, we included heterotrophic protists in this chapter as all metazoons (multicellular animals) originate from a part of this taxon. 

5 Changes in Polyphosphate Content under Stress Conditions 

The ammonium-induced cytoplasmic alkalization in the unicellular algae Dunaliella salina resulted in degradation of long-chain PolyPs to PolyP3 (Pick etal, 1990 Bental etal, 1990 Pick and Wess, 1991). The hydrolysis was shown to correlate with the recovery of cytoplasmic pH and might provide the pH-stat mechanism to counterbalance the alkaline stress. 

The alga Phaerodactilum tricornutum was found to respond to hyperosmotic stress by a marked elongation of PolyP and a decrease in its total amount, while exposure to hypoosmotic stress resulted in a higher content of shorter PolyPs and an increased total PolyPs content (Leitao et al., 1995). It is probable that, such variations might allow the adjustment of the intracellular osmotic pressure to an extracellular one. 

In conclusion, it should be said that the PolyP-metabolizing enzymes in algae have been little studied. An activity, which transferred Pi from PolyP to ADP, was observed in cell-free extracts from Chlorella (Iwamura and Kuwashima, 1964) and Acetabularia (Rubtsov and Kulaev, 1977). Exopolyphosphatase activity was found in Acetabularia (Rubtsov and Kulaev, 1977), while polyphosphate glucokinase activity was not found in algae (Uryson and Kulaev, 1970). 

PolyP in protozoa was found long ago (Ebel et al., 1958b Mattenheimer, 1958 Janakidevi et al, 1965 Rosenberg, 1966). Its metabolism was studied with the purpose of searching for specific biochemical peculiarities of parasitic representatives of this taxon, which could offer prospects for drug development. 

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Protozoa Protozoacide Protozoal infections Protozoan diseases Prot. rettgeri Prot. rettgeri 120 Protriptyline [438-60-8]... 

Defaunation is a term used to describe the elimination of protozoa from the mmen. Ruminal protozoa allegedly have both positive and negative effects on animal performance (5,34). Defaunation may increase mminal microbial efficiency because less methane is produced and less proteolysis occurs... 

Microscopists in every technical field use the microscope to characterize, compare, and identify a wide variety of substances, eg, protozoa, bacteria, vimses, and plant and animal tissue, as well as minerals, building materials, ceramics, metals, abrasives, pigments, foods, dmgs, explosives, fibers, hairs, and even single atoms. In addition, microscopists help to solve production and process problems, control quaUty, and handle trouble-shooting problems and customer complaints. Microscopists also do basic research in instmmentation, new techniques, specimen preparation, and appHcations of microscopy. The areas of appHcation include forensic trace evidence, contamination analysis, art conservation and authentication, and asbestos control, among others. 

This article discusses the main diseases caused by protozoa and the important chemotherapeutic antiprotozoal agents currently ia use or ia an advanced state of development. Not all alternative proprietary names are given for each dmg. There are excellent sourcebooks on protozoology and parasitology (2—8). 

In cattle, infections by a single species of protozoan are unusual combinations of the protozoa such as Eimeria Eimeria bovis and Eimeria... 

Cryptosporidiosis, an intestinal infection caused by protozoa of C ptosporidium species is a taxonomicaHy related disease (12). The disease affects animals, such as calves, lambs, and chickens, and infects humans woddwide, especially infants and children in developing countries. Symptoms range from mild self-limiting diarrhea and abdominal pain to a potentially fatal extreme diarrhea that results in weight loss and poor nutritional absorption. 

Malaria is transmitted by the bite of an infected female Anopheles mosquito, one of the few species of the insect capable of carrying the human malaria parasite. The responsible protozoa ate from the genus P/asmodium of which only four of some 100 species can cause the disease in humans. The remaining species affect rodents, reptiles, monkeys, birds, and Hvestock. The species that infect humans are P/asmodium falciparum Plasmodium vivax Plasmodium malariae and Plasmodium ovale. Note that concomitant multiple malaria infections are commonly seen in endemic areas, a phenomenon that further compHcates choice of treatment. 

Bactericide, fungicide, virucide,proto acide, andalgicide are chemical agents that kill either bacteria, fungi (including yeasts), vimses, protozoa, or algae. They may... 

Fish are generally more suseeptible to poisoning than mieroseopie plants or other animals as sueh they are a good indieator speeies. A summary of the eoneentrations of seleeted substanees at whieh toxie effeets have been deteeted in baeteria, algae, emstaeia and protozoa is given in Table 16.14. 

Bacteria- Escherichia coli Creen algae-Scenedesmus quadricauda Daphnia magna Protozoa microregma... 

Bacteria are smaller than protozoa and are responsible for many diseases, such as typhoid fever, cholera, diarrhea, and dysentery. Pathogenic bacteria range in size from 0.2 to 0.6 /tm, and a 0.2 /tm filter is necessary to prevent transmission. Contamination of water supplies by bacteria is blamed for the cholera epidemics, which devastate undeveloped countries from time to time. Even in the U.S., E. coli is frequently found to contaminated water supplies. Fortunately, E. coli is relatively harmless as pathogens go, and the problem isn t so much with E. coli found, but the fear that other bacteria may have contaminated the water as well. Never the less, dehydration from diarrhea caused by E. coli has resulted in fatalities. 

Viruses are the 2nd most problematic pathogen, behind protozoa. As with protozoa, most waterborne viral diseases don t present a lethal hazard to a healthy adult. Waterborne pathogenic viruses range in size from 0.020-0.030 jtim, and are too small to be filtered out by a mechanical filter. All waterborne enteric viruses affecting humans occur solely in humans, thus animal waste doesn t present much of a viral threat. At the present viruses don t present a major hazard to people drinking surface water in the U.S., but this could change in a survival situation as the level of human sanitation is reduced. Viruses do tend to show up even in remote areas, so a case can be made for eliminating them now. 

Microbial Contaminants For microbial contaminants that may present public health risk, the MCLG is set at zero because ingesting one protozoa, virus, or bacterium may cause adverse health effects. EPA is conducting studies to determine whether there is a safe level above zero for some microbial contaminants. So far, however, this has not been established. 

Amoeba (plural, amoebae) Protozoa that can alter their cell shape, usually by the extrusion of one or more pseudopodia. 

Protozoa A group of motile microscopic animals (usually single-celled and aerobic) that sometimes cluster into colonies and often consume bacteria as an energy source. 

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