Mycoplasma pneumoniae: Proposed Nomenclature for Atypical Pneumonia Organism (Eaton Agent)

Abstract

Previous epidemiologic studies have shown that most primary atypical pneumonia illnesses in which cold agglutinins develop are associated with the agent first described by Eaton, Meiklejohn, and van Herick in 1944 (1-8). In addition the agent causes a spectrum of effects ranging from inapparent infection to febrile respiratory disease without pneumonia (5, 6).Recent studies have established that the organism, previously known as "primary atypical pneumonia virus" or "Eaton agent", is not a virus but a member of the genus Mycoplasma (pleuropneumonia-like organisms) (9-11). Thus, at least 30 strains have been grown in cell-free semisolid or liquid medium containing bovine heart infusion, yeast extract, and horse serum (10-13). Growth does not occur in the absence of serum or a suitable substitute such as egg yolk (10, 14). The colonies which grow on semisolid *agar medium exhibit a colonial morphology and fine structure characteristic of Mycoplasma (10). Certain microbial inhibitors such as thallium acetate, penicillin, and amphotericin B do not affect growth of the organism (10, 11). The agent is inhibited, however, by the tetracycline group of antibiotics (15).Until recently only four species of mycoplasma were known to infect man. These are M. hominis type 1, M. hominis type 2, M. salivarium, and M. fermentans. (16-18). When the atypical pneumonia organism was compared with these species by immunofluorescence or complement-fixation tests it was antigenically distinct (10, 19-21). It resembles M. fermentans in utilizing glucose and other sugars (22). The agent differs biologically from the four recognized human species of Mycoplasma by its ability to produce rapid and complete hemolysis of guinea-pig and horse red cells (23, 24). Under 662 R. M. CHANOCK

Metabolic rate and body size are linked with perception of temporal information

“…(1995); (4) Bornshein & Tansley (1961); (5) Ault & House (1987); (6) Coile et al. (1989); (7) Hanyu & Ali (1963); (8) McComb et al. (2010); (9) Levenson et al.…”

Community-acquired pneumonia in Europe: causative pathogens and resistance patterns

“…In the twentieth century, most discoveries in the field of pneumonia aetiology related to atypical pathogens and viruses, with many of the new discoveries being made outside Europe. In the USA, the term atypical pneumonia was coined by REIMANN [14] in 1933, and the "Eaton Agent", subsequently to be called Mycoplasma pneumoniae, was identified as the cause [15]. Although psittacosis was first described in Switzerland in 1880 [16], the causative organism was not described until 1930, and then simultaneously in England, Germany and the USA.…”

Mycoplasma pneumoniaeand Its Role as a Human Pathogen

“…In 1961 Marmion and Goodburn postulated that the Eaton agent was a PPLO and not a virus (281). Chanock et al succeeded in culturing the Eaton agent on cell-free medium (68) and proposed the taxonomic designation M. pneumoniae in 1963 (67).…”