A microorganism smaller than bacteria but larger than a virus.
A genus of microorganisms which causes several diseases including Q fever and typhus.
Small micro-organisms possessing some of the characteristics of bacteria (visibility, binary fission) and other features associated with viruses (obligatory intracellular parasitism). Some species cause typhus fever in man. Rickettsia are small (0.35 pm) Gram¬ negative cocco-bacilli, best stained by methods such as Castaneda or Macchiavello. Yolk-sac cultivation in chick embryos (from animal material, following intraperitoneal injection of patient’s blood) is reserved for purposes such as vaccine production; routine diagnosis is by the Weil-Felix reaction {which see) and on occasion by complement fixation.
Any of a group of bacteria-like microorganisms that live as parasites in ticks, fleas, lice, and mites and are transmitted to humans by these vectors. Rickettsia-caused diseases include Rocky Mountain spotted fever and typhus.
The general term given to a group of bacteria which are the causal agents of typhus fever and a number of typhus-like disease, such as rocky mountain spotted fever, Japanese River fever, and scrub typhus. These micro organisms are usually conveyed to man by lice, fleas, ticks, and mites.
A genus of bacteria of the family Rickettsiaceae, order Rickettsiales. They are obligate intracellular parasites (must be in living cells to reproduce) and are the causative agents of many diseases. Their vectors are arthropods such as fleas, ticks, mites, and lice.
Term applied to any of the bacteria belonging to the family Rickettsiaceae.
Within the realm of microbiology, there exists a distinctive and rod-shaped microorganism capable of propagating solely within a living cell. This infectious entity, known as a rickettsia, thrives in the intricate dynamics of host organisms. One of the diseases caused by this particular microorganism is scrub typhus, a condition classified under the category of rickettsial diseases.
Rickettsiae are microscopic organisms that share characteristics with both bacteria and viruses. While they resemble small bacteria, they can only reproduce by infiltrating living cells. These microorganisms mainly parasitize arthropods like ticks, lice, fleas, and mites, but can also infect larger animals, including humans, through insect bites. Diseases caused by rickettsiae in humans include Q fever, Rocky Mountain spotted fever, and typhus.
A group of bacteria-like microorganisms that cause typhus and various other fevers.