Species Of Mollicutes Research Articles

Male germ cell specific sulfogalactoglycerolipid is recognized and degraded by mycoplasmas associated with male infertility

Sulfogalactosylglycerolipid (SGG) is the major mammalian male germ cell glycolipid and has been implicated in sperm/egg binding. Mycoplasma pulmonis, a species of Mollicutes, is associated with male infertility in rodents. Purified SGG incubated in the presence of M. pulmonis was enzymatically degraded by both desulfation and deacylation. Desulfation occurred primarily at alkaline pH, and deacylation also increased with increased pH, indicating that these represent novel enzymatic activities. Digestion was facilitated, but not dependent on, the presence of detergent. Rat spermatozoa exposed to M. pulmonis showed a reduction in SGG content which was particularly marked for cauda (mature) spermatozoa. With the aid of tlc overlay binding procedure, intact M. pulmonis were found to bind specifically to sulfated glycolipids and thus SGG may provide the cell membrane receptor for this organism. The topology of mycoplasma binding to rat sperm was consistent with the known topology of sperm SGG. The reduced binding (and subsequent digestion) of caput spermatozoan SGG correlates with the membrane colocalization of SGG and its endogenous binding protein at this stage. Separation of SGG and its binding protein during epididymal sperm maturation appears to facilitate M. pulmonis binding to and digestion of cauda sperm SGG. The binding and degradation of the sperm SGG by M. pulmonis may play a role in the induction of infertility which follows infection with these organisms by interfering in sperm/egg receptor recognition.

Proposal of Minimal Standards for Descriptions of New Species of the Class Mollicutes: International Committee on Systematic Bacteriology Subcommittee on the Taxonomy of Mollicutes

A proposal for minimal standards for descriptions of new species of the class Mollicutes is presented here with the approval of the International Committee on Systematic Bacteriology (ICSB) and its Judicial Commission. The proposal is a revised and extended version of a similar proposal of minimal standards for descriptions of species of the order Mycoplasmatales previously published by the Subcommittee. The major characteristics of the class Mollicutes are summarized. The classification of an organism as a member of the class is based primarily on the following criteria: Lack of a cell wall, typical colonial appearance, filterability through a membrane filter with a pore size 450 nm in diameter, and absence of reversion to a bacterium under conditions ordinarily favorable for reversion. Placement of these organisms into families is based on genome size, sterol requirements, and morphology; their assignment to genera is based on morphological, cultural, and biochemical properties. Demonstration that an organism differs from existing species requires determination of serological, cultural, and biochemical characteristics. Other tests may be useful or, under certain conditions, necessary.

Proposal for classifying human strain navel and related simian mycoplasmas as Mycoplasma primatum sp. n.

Mycoplasmas isolated from simian (Cercopithecus aethiops) tissues were shown to have biological, biochemical, and serological properties and electrophoretic cell protein patterns similar to strain Navel isolated from man 15 years ago. The simian and human Navel strains comprised a single serogroup, distinct from the established Mycoplasma and Acholeplasma species of the class Mollicutes. It is proposed that strains with the properties described be named Mycoplasma primatum.