- A bacteria, virus, or fungus that takes advantage of certain opportunities to cause disease. Those opportunities are called opportunistic conditions. These microorganisms are often ones that can lie dormant in body tissues for many years, such as the human herpes viruses, or that are extremely common but usually cause no symptoms of illness. When the immune system cannot raise an adequate response, these microorganisms are activated, begin to multiply, and soon overwhelm the body’s weakened defenses. See also opportunistic condition, opportunistic infection.
Medical dictionary. 2011.
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opportunistic microorganism — (pathogen) A microorganism that is usually free living or a part of the host s normal microbiota, but which may become pathogenic under certain circumstances, such as when the immune system is compromised … Dictionary of microbiology
opportunistic — [äp΄ər to͞o nis′tik, äp΄ərtyo͞onis′tik] adj. 1. of or characterized by opportunism ☆ 2. designating or of an infection or disease caused by a microorganism (opportunistic microorganism) that is normally not virulent but that can cause a serious… … English World dictionary
Opportunistic infection — An infection that occurs because of a weakened immune system. Opportunistic infections are a particular danger for people with AIDS. The HIV virus itself does not cause death, but the opportunistic infections that occur because of its effect on… … Medical dictionary
Opportunistic condition — A condition that occurs especially or exclusively in persons with a weak immune system due, for example, to AIDS, cancer or immunosuppressive drugs, such as corticosteroids or chemotherapy. An opportunistic condition may be an infection, such as… … Medical dictionary
opportunistic — 1. Denoting an organism capable of causing disease only in a host whose resistance is lowered, e.g., by other diseases or by drugs. 2. Denoting a disease caused by such an organism. * * * op·por·tu·nist·ic t(y)ü nis tik adj 1) of, relating to, or … Medical dictionary
opportunistic — adjective Date: 1892 taking advantage of opportunities as they arise: as a. exploiting opportunities with little regard to principle or consequences < a politician considered opportunistic > b. feeding on whatever food is available <… … New Collegiate Dictionary
opportunistic infection — noun any infection caused by a microorganism that does not normally cause disease in humans; occurs in persons with abnormally functioning immune systems (as AIDS patients or transplant patients receiving immunosuppressive drugs) • Hypernyms:… … Useful english dictionary
opportunistic — opportunistically, adv. /op euhr tooh nis tik, tyooh /, adj. 1. adhering to a policy of opportunism; practicing opportunism. 2. Pathol. a. (of a microorganism) causing disease only under certain conditions, as when a person s immune system is… … Universalium
opportunistic — op•por•tun•is•tic [[t]ˌɒp ər tuˈnɪs tɪk, tyu [/t]] adj. 1) adhering to a policy of opportunism; practicing opportunism 2) pat a) (of a microorganism) causing disease only under certain conditions, as when a person s immune system is impaired b)… … From formal English to slang
Infection, opportunistic — An infection that occurs because of a weakened immune system. Opportunistic infections are a particular danger for people with AIDS. The HIV virus itself does not cause death, but the opportunistic infections that occur because of its effect on… … Medical dictionary