- A genus of nonmotile, anaerobic, chemoorganotrophic bacteria (family Peptococcaceae) containing Gram-positive, spherical cells that occur singly, in pairs, tetrads, or irregular masses, and rarely in short chains. They are frequently found in association with pathologic conditions. The type species is P. niger. [G. pepto, to digest, + kokkos, berry]- P. aerogenes former name for Peptostreptococcus asaccharolyticus.- P. constellatus a bacterial species found in tonsils, purulent pleurisy, appendix, the nose, throat, and gums, and infrequently on the skin and in the vagina.- P. niger a bacterial species found once, in the urine of an aged woman; type species of the genus P..
* * *pep·to·coc·cus .pep-tə-'käk-əs n1) cap a genus of anaerobic gram-positive coccal bacteria that do not form spores and are now considered to comprise a single species (P. niger)
* * *Pep·to·coc·cus (pep″to-kokґəs) [Gr. pepton digestion + kokkos berry] a genus of gram-positive bacteria of the family Peptococcaceae, consisting of anaerobic, chemo-organotrophic cocci, occurring singly or in pairs, tetrads, or irregular masses. Pathogenic species have been assigned to other genera. The type species is P. niґger.
Medical dictionary. 2011.