Protozoan parasites control

Copper sulfate is used to control protozoan fish ectoparasites including Ichthyopthirius, Tri-chodina, and Costia. The effectiveness of the treatment diminishes with increasing total alkalinity and total hardness of the water (Straus and Tucker 1993). Copper compounds now used to control protozoan parasites of cultured red drum (Sciaenops ocellatus) include copper sulfate, copper sulfate plus citric acid, and chelated copper compounds (forms of copper bound by sequestering agents, such as ethanolamine) chelated copper compounds are considered less toxic to fish than copper sulfate and at least as effective in controlling parasites (Peppard etal. 1991). 

Fumidil-B manufactured by Abbott Laboratories is the water soluble bicyclohexylammonium salt of the antibiotic fumagillin produced by the fermentation of Aspergillus fumigatus and is used world-wide for the prevention and control of Nosema apis, a disease in adult honey bees. The drug attacks the actively multiplying disease producing protozoan parasites in the gut of the adult bee. 

The sandfly Lutzomyia longipalpis is the vector of the protozoan parasite Leishmania chagasi, the causative agent of visceral leishmaniasis in South and Central America. Population control of L. longipalpis is therefore of urgent importance to prevent the disease. In 1994, Hamilton and coworkers isolated the male-produced pheromone of L. longipalpis from Jacobina, Brazil, and proposed its structure as 3-methyl-a-himachalene (96, Figure 4.47) with unknown stereochemistry. We first synthesized ( R, 3R, 1 S )-( )-96.81 Enantiomer separation (optical resolution) of a synthetic intermediate enabled us to prepare both the enantiomers of 96, and their bioassay and GC comparisons with the natural pheromone showed the latter to be (lS,3S,lR)-96. 

Protozoan parasites can induce chronic infections in mammals, and therefore large amounts of antibody (IgM + IgG) are produced in response to infection. The external surfaces, and the antigens contained therein, are important in the control of protozoan infections and many effective/protective antibody mechanisms are directed against them. 

Although antibiotics have rendered possible medical control of various infectious agents (mainly bacterial), numerous pathogens remain for which no effective treatment exists. Most of these pathogens are non-bacterial (e.g. viral, fungal and parasitic, including protozoan). In addition, the over-use/abuse of antibiotics has hastened the development of antibiotic-resistant super-bacteria , which have become a serious medical problem. 

Viruses are obligate intracellular parasites. They only exhibit activity by infecting other living organisms, thus they are not a practical concern in industrial microbiological fields. The exception is where viral contamination of the product or process represents a threat of transmission of disease. Microscopic insects and protozoans are also not addressed in this article (see Insect control technology). 

Control Usually controlled by natural enemies (blister beetle larvae, ground beetles, predatory flies, birds, parasitic nematodes, fungal dieases) cultivate fields in fall to kill overwintering eggs aerial sprays of commercial protozoan disease Nosema locmtae) may be effective over large areas but is not useful on a home-garden scale. 

Unlike most other types of infection, protozoan diseases are often chronic, lasting for months to years. When associated with a strong host immune response, this type of long-term infection is apt to result in a high incidence of immunopathology. Until recently the importance of host immune response in controlling many parasite infections was not fully appreciated, but the impact of HIV infection on many parasitic diseases has highlighted this relationship. 

The use of natural products in the treatment and control of human parasitic diseases is referred in the texts of traditional systems of medicine. Ancient medical practioners of traditional remedies in China, India, Egypt, the Middle East and Europe knew several plants having activity against various diseases caused verv likely by protozoans, though the etiology and epidemiology of such diseases were not well defined in those days. Many of these remedies are still used, particularly in countries where traditional systems of medicine are a part of the health care systems. In India it is believed that 50-75% of the population uses traditional drugs Irecause of their lower cost, easy access and faith in them [1]. 

Landfear, S. M. and Wirth, D. F. (1984) Control of tubulin gene expression in the parasitic protozoan Leishmania enriettii. Nature 309 716-717. 

Ideally, prevention would be the most efficient way to control parasitic diseases, but despite numerous efforts there are no effective vaccines against any of the clinically important parasites. For the moment, drugs are therefore the mainstay in our control of parasitic protozoans when simple prevention measures fail or prove impractical. However, a majority of the drugs directed against parasites have far from optimal pharmacological properties, with narrow therapeutic indices and limiting host toxicity. The arsenal of antiprotozoal drugs is thus limited, and this is further complicated by a rapid rise... 

The natural ecosystem maintains a delicate balance between pests and predators. Pest insects can be controlled by the artificial release of predators. One example is a parasitic wasp, Diadegma insulare. The adult female wasp lays eggs in a Plutella xylostella larva and pupates inside the cocoon of the mature larva. This and other insect predators are available commercially, but the usage is limited. Protozoa and nematodes are also used in insect pest control. One example of a protozoan that effectively infects locusts and controls the population is Nosema locustae. A commercially available nematode insect control agent is Steinemema carpocapsae. This nematode parasitizes scarab larvae with a symbiotic Photorhabdus bacterium that produces insecticidal toxins. 

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