Bacterial agent

Bacteria are single-celled organisms that range in shape and size from cocci (spherical cells), with a diameter of 0.5-1.0 m (micrometer), to long rod-shaped organisms known as bacilli, which may be from 1-5 m in size. Chains of bacilli have been known to exceed 60 m in size. Some bacteria have the ability to turn into spores. In this form, the bacteria are more resistant to cold, heat, drying, chemicals, and radiation than the bacterial form would be. When in the spore form, bacteria are inactive, or dormant, much like the seeds of a plant. When conditions are favorable, the spores will germinate just like seeds. 

Bacteria have two methods by which they can cause disease in humans and animals. The first is by attacking the tissues of the living host. Second, aU living organisms produce waste. Bacteria may produce a toxic or poisonous waste material that causes disease in the host. Some bacteria attack using both methods. 

Anthrax spores are highly persistent and resist adverse enviromnental elements and remain viable for hundreds of years in soil and in dried or processed hides. Spores are resistant to drying, heat, and sunlight. They have been known to survive in milk for up to 10 years, on dried filter paper for 41 years, on dried silk threads for up to 71 years, and in pond water for 2 years. 

Onset of the second phase can be sudden, with the evolution of shortness of breath and cyanosis. Ingestion of contaminated meat may also cause infection, although this is a rare occurrence. Symptoms from ingestion exposure to anthrax include acute inflammation of the intestinal tract, nausea, loss of appetite, vomiting, and fever, which is followed by abdominal pain, vomiting of blood, and severe diarrhea. Approximately 25 to 60% of those victims who ingest anthrax will die. 

Antibiotic treatment should begin as soon as possible. Streptomycin is the drug of choice for treatment, but others, such as tetracyclines, chloramphenicol, gentamicin, or one of the sulfonamides, may also be effective. A vaccine for the plague is available, however, it is only effective as a preventative measure once someone is exposed, the vaccine will not help. The initial dose of vaccine is followed by a second one 1-3 months later and a third one 3-6 months later. Booster shots are administered at 6, 12, and 18 months and then every 1 to 2 years. As with all vaccines, the level of protection is related to the size of the dose vaccination defense could be overwhelmed by extremely high doses of the bacteria. 

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Some applications, such as incise drapes require loading of the PSA matrix with anti-bacterial agents. Proper selection of the monomers allows the PSA to be compatible with compounds like iodine, while maintaining the adhesion to the skin. 

Bacterial agents, particularly Staphylococcus aureus, P-hemolytic streptococci, and Escherichia coli may give rise to pyomyositis, a form of acute suppurative... 

Hydrochloric acid in combination with chlorine dioxide can be used as a treatment fluid in water-injection wells that get impaired by the deposition of solid residues [332,333]. The treatment seems to be more effective than the conventional acidizing system when the plugging material contains iron sulfide and bacterial agents because of the strongly oxidative power of chlorine dioxide. Mixtures of chlorine dioxide, lactic acid, and other organic acids [1172,1173] also have been described. 

Bacterial agents, such as Bacillus anthracis (the causative agent for anthrax), or Yersinia pestis (the causative agent for plague). 

Development of the LAL assay was based upon the observation that the presence of Gramnegative bacteria in the vascular system of the American horseshoe crab, Limulus polyphemus, resulted in the clotting of its blood. Tests on fractionated blood showed that the factor responsible for coagulation resided within the crab s circulating blood cells, i.e. the amoebocytes. Further research revealed that the bacterial agent responsible of initiation of clot formation was endotoxin. 

Takasuna, K., Kasai, Y., Usui, C., Takahashi, M., Hirohashi, M., Tamura, K. and Takayama, S. (1992). General pharmacology of the new quinolone anti-bacterial agent levofloxacin. Arzneim.-Forsch./Drug Res. 42(I)(3a) 408-418. 

Anthrax Bacterial agent that may cause inhalation anthrax, cutaneous anthrax, or gastrointestinal anthrax disease. 

Tularemia Disease caused by a bacterial agent. Examples include ulceroglan-dular tularemia, glandular tularemia, typhoidal tularemia, oculoglandular tularemia, oropharyngeal tularemia, and pneumonic tularemia. 

Anti-bacterial agent injected in outer polymer layer to reduce contamination of bills... 

A further extention of herd medication has often in the past been referred to as prophylactic treatment or disease prevention. Both terms are partially correct but the rationale for their application requires a basic knowledge of epidemiology. The application of pre-emptive medication depends upon the knowledge that a particular bacterial agent has been introduced into a population and is causing clinical disease in individuals within that population (5). Previous veterinary experience will have indicated that if medication is not applied to the group or herd then there will be a conti-... 

Anti-arrhythmic agents Anti-bacterial agents Anti-coagulants Anti-depressants... 

In endemic areas malaria should always be considered and, if possible, checked by blood film analysis otherwise empiric antimalarial treatment may be indicated (see section on malaria). Empiric treatment should further cover the spectrum of bacterial agents likely to cause septic infections in the particular patient. The potentially fatal course of septic disease requires an antibiotic regimen that is rapidly lethal for the causative agent, and preferably attains adequate levels at the site of infection quickly. Therefore, treatment regimens usually include a combination of two (sometimes three) antibiotics that are given by a parenteral route (intramuscularly or preferably by intravenous infusion). 

It is structurally unrelated to other topical anti-bacterial agents. Most of the gram... 

Antimicrobial agents are frequently used before the pathogen responsible for a particular illness or the susceptibility to a particular antimicrobial agent is known. This use of antimicrobial agents is called empiric (or presumptive) therapy and is based on experience with a particular clinical entity. The usual justification for empiric therapy is the hope that early intervention will improve the outcome in the best cases, this has been established by placebo-controlled, double-blind prospective clinical trials. For example, treatment of febrile episodes in neutropenic cancer patients with empiric antimicrobial therapy has been demonstrated to have impressive morbidity and mortality benefits even though the specific bacterial agent responsible for fever is determined for only a minority of such episodes. 

There has been some controversy concerning the DPT combination shot. Of the three antigens in this mixture the pertussis is the only bacterial agent. It can cause an active infection. The CDC recommends using a safer agent - DtaP - which may contain smaller doses of the diptheria or pertussis toxiods. 

Another threat which comes with natural products is microbes. The ingredients in cosmetics, such as water, oils, carbohydrates, minerals, and proteins, make them an ideal medium in which bacteria can multiply, as some purchasers of purely natural beauty products have discovered to their cost, not least of which is the disagreeable odour they emit which indicates they are going off. Even such natural products must now contain anti-bacterial agents and these must be proven to work, which is why they are generally synthetic chemicals. The ones most used and most effective at... 

In southern California, the Anaheim development started in 1857 and finally planted over a thousand acres of grapes in that area. Unfortunately, it was destroyed after 1888 by a mysterious vine disease, now known as Pierce s disease (from a bacterial agent). 

Data are available for acute and intermediate inhalation exposures that resulted in death of animals. For the most part, these exposures also affected the respiratory tract and the immune response to bacterial agents. An intermediate inhalation exposure study of rats prior to mating and during pregnancy did not result in fetotoxic or teratogenic effects. Limited information is available regarding chronic inhalation exposure. 

Figure 1.4. Paul Ehrlich. Paul Ehrlich was a German Jewish physician and scientist, who was inspired by and initially worked with Robert Koch (who discovered the causative bacterial agents of Anthrax, Tuberculosis, and Cholera). Left Ehrlich s portrait on a 200 deutschmarks bill (now obsolete).

We have already seen a case of large casualties that was due to food contamination with a bacterial agent, the 1984 attack by the Rajneeshee cult with Salmonella typhimurium, although no deaths were directly attributable to this hioterrorist attack. This type of assault—basically a crime of opportunity using food-borne bacteria—is probably the more likely type of bioterrorist event we may encounter in the future. 

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