[ad_1]
Pathogens are microorganisms that can produce disease, including bacteria, fungi, protozoa, and prions. Bacterial pathogens can cause disease through virulence factors, including the production of toxins and the ability to invade host tissues. Treatment options include antibiotics, chemotherapeutic agents, and hybrids.
Pathogen comes from two Greek words: pathos which means “disease” and genein which means “to produce”. Refers to an agent or microorganism capable of producing disease. Prions are an example of a pathogen. When it comes to a disease that spreads microorganisms, the culprit could be a pathogenic fungus, protozoan, or bacterium. Viruses can be included as microorganisms, but since there is controversy as to whether they are alive, they can also be placed in the agent category.
Not all bacteria are pathogens, but those that are can threaten the lives of animals, people and plants. Examples of bacterial pathogens include Mycobacterium tuberculosis, Streptococcus, Bacillus anthracis, Rickettsia, Listeria and Salmonella. The pathogenicity of a bacterium is a measure of its ability or likelihood to cause disease, measured quantitatively as virulence. The particular factors that explain the virulence of bacterial pathogens are referred to as virulence factors.
Virulence factors include a variety of properties that contribute to its success in establishing itself in or on its host and causing disease. Bacterial pathogens can have relatively few or many virulence factors. Factors that bacterial pathogens may have include the production of toxins, the presence of proteins that aid in attachment to a host, and the ability to protect their own surface.
Another way to look at the efficacy of bacterial pathogens is to look at them in terms of invasiveness and toxicity. In this case, the ability to produce toxins that target tissue both near and far from the point of growth or invasion is separate from any factors that allow the bacteria to successfully invade another organism.
Pathogenic bacteria begin their attacks on a host through colonization, establishing themselves in the host’s tissues, usually at a point that maintains contact with the external environment. With a human host, this would include the conjunctiva, digestive tract, respiratory tract, and urogenital tract. Bacterial pathogens use adhesins to interact with receptors on host cells.
The next stage of infection with bacterial pathogens is called invasion. Factors that may aid invading bacteria include substances called invasins that serve two purposes: to damage host cells and to allow the bacterial pathogen to spread.
Infectious diseases caused by bacterial pathogens can be treated with one of three different groups of antimicrobial agents. The group of natural antimicrobials are called antibiotics; the group of chemically synthesized antimicrobials are called chemotherapeutic agents; and hybrids start with a natural substance that is modified. Some members of the first group can now be synthesized.
