A Cytological Study of Nocardia Corallina and Other Actinomycetes

Abstract

The cytology and life cycles of the Actinomycetes recently have received critical study. The presence of an apparent life cycle has been shown in Streptomyces (Kijeneberger-Nobel, 1947) and Actinomyces (Morris, 1951). McClung (1950) stained nuclear-like bodies and studied the proes of fragmentation in several species of Nocadia. The investigation, however, omitted a careful examination of germination, cytology, and division of the coccoidal forms. These recent cytological studies have relied primarily on the acid-Giemsa nuclear stain and various cell wall stains, some of which will not stain cross septa. This investigation was undertaken to determine the cytology of the genus Nocadia and other Actinomyetes by using the Chance crystal-violet nuclear stain, cell wall stains, and phase microscopy. The crystal-violet nuclear stain does not involve acid hydrolysis or other harsh treatment and should prove of value in clarifying the nuclear cytology of the Actinomycetes. AT~19L AND METHODS Nocadia corallina (ATCC-4273), which readily fragments into coccoidal forms, was chosen for detailed study. Nocardia blakwelli (ATCC4-846) and Streptomces grieueu (ATCC-10137) were studied to a leser extent for comparisOn pur

II. REPRODUCTION OF Bacterionema matruchotii1

“…Aerobic, starting with a bacillus-like body. Observations of the aerobic growth of bacillus-like bodies gave results similar to those illustrated above with anaerobic incubation (figures 12 to 21) and with aerobic incubation (figures 30 to 32).…”

“…To show the generality of the above mechanism, the development of a number of bacillus-like bodies has been followed. A typical sequence of events is illustrated in figures12 to 21, in which observa-…”

COMPARISON OF THE DEVELOPMENTAL CYCLES OF SOME MEMBERS OF THE GENUS NOCARDIA

“…In the most recently revised descriptions of the genus Nocardia (Breed, Murray, and Smith, 1957;Waksman, 1961), a general morphological lifehistory of members of the genus was presented. In these descriptions several patterns of reproduction are mentioned whose existence was not confirmed in the present studies or by McClung (1949McClung ( , 1955, Webb, et al (1954), and Hagedorn (1959a,b) in previous investigations.…”

“…Some of the conflicting opinions and conclusions resulting from these investigations were included in his reviews. We feel that the results of the present and earlier studies (McClung, 1949(McClung, , 1954(McClung, , 1955Webb, Clark, and Chance, 1954;Webb and Clark, 1957;Hagedorn, 1959a,b) offer sufficient evidence to allow a critical re-evaluation of sev-eral of the divergent concepts which have been offered concerning the genus Nocardia. Re-evaluation of some of these conflicting concepts may serve a twofold purpose: (i) a better characterization of the biology of the group, based on the cytologically observed developmental cycles, and (ii) clarification of some of the taxonomic problems which have been a direct result of these studies.…”

Ultrastructure of Nocardia Cell Growth and Development on Defined and Complex Agar Media

“…The genus Nocardia is characterized by forming filamentous, branched cells which fragment to shorter rod or coccoid units (20; Bergey's Manual, 7th ed.). There have been several light microscope studies of this developmental process (1, 2, 3, 14,20,21), but there have been few ultrastructural studies of Nocardia. Hagedorn (8) studied thin sections of N. corallina, but was unable to demonstrate intracytoplasmic membranes within these cells.…”