Biomaterial Database

Structure of bacterial L forms and their parent bacteria. 1965

C Weibull

Weibull, Claes (Rocky Mountain Laboratory, Hamilton, Mont.). Structure of bacterial L forms and their parent bacteria. J. Bacteriol. 90:1467-1480. 1965.-Light and electron microscopic studies were done on normal cells and L forms of Proteus mirabilis, Staphylococcus aureus, and Corynebacterium sp. grown in liquid media. Under the prevailing growth conditions, the L forms studied were morphologically indistinguishable from one another. They appeared as approximately spherical elements occurring singly or more often connected with each other by thinner portions of cell material. In sections of large L forms, the following structures were seen: a peripheral, triple-layered ("unit") membrane, a granular cytoplasm, nuclear regions, and vacuoles limited by membranes. Small bodies often were present inside the vacuoles. These bodies also contained a peripheral membrane and a granular cytoplasm but usually no nuclear regions. The normal bacteria from which the L forms were derived differed markedly in structure from one another, especially in the surface layers of the cells.

UI	MeSH Term	Description	Entries
D007740	L Forms	Bacterial variants, unable to form a complete cell wall, which are formed in cultures by various bacteria; granules (L bodies) appear, unite, and grow into amorphous bodies which multiply and give rise to bacterial cells morphologically indistinguishable from the parent strain.
D008853	Microscopy	The use of instrumentation and techniques for visualizing material and details that cannot be seen by the unaided eye. It is usually done by enlarging images, transmitted by light or electron beams, with optical or magnetic lenses that magnify the entire image field. With scanning microscopy, images are generated by collecting output from the specimen in a point-by-point fashion, on a magnified scale, as it is scanned by a narrow beam of light or electrons, a laser, a conductive probe, or a topographical probe.	Compound Microscopy,Hand-Held Microscopy,Light Microscopy,Optical Microscopy,Simple Microscopy,Hand Held Microscopy,Microscopy, Compound,Microscopy, Hand-Held,Microscopy, Light,Microscopy, Optical,Microscopy, Simple
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D011511	Proteus	A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs in the intestines of humans and a wide variety of animals, as well as in manure, soil, and polluted waters. Its species are pathogenic, causing urinary tract infections and are also considered secondary invaders, causing septic lesions at other sites of the body.
D003352	Corynebacterium	A genus of asporogenous bacteria that is widely distributed in nature. Its organisms appear as straight to slightly curved rods and are known to be human and animal parasites and pathogens.
D013210	Staphylococcus	A genus of gram-positive, facultatively anaerobic, coccoid bacteria. Its organisms occur singly, in pairs, and in tetrads and characteristically divide in more than one plane to form irregular clusters. Natural populations of Staphylococcus are found on the skin and mucous membranes of warm-blooded animals. Some species are opportunistic pathogens of humans and animals.
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In