ABSTRACT
Mycoplasma spp. are members of the class Mollicutes, have the smallest cells among free-living eubacteria, and have genomes presumed to approach the minimal essential information for independent cellular life (Brown 2011). Mycoplasma and the other mollicutes probably evolved from gram-positive ancestors (Maniloff 1992, 2002) by reductive processes that resulted in essentially obligate commensalism or parasitism of eukaryotic host cells. The distinguishing characteristics of mollicutes include small cell size (200-500 nm), small genome size (580-2200 kbp), low G + C content (typically in the range of 23-34 mol%, but 40 mol% in Mycoplasma pneumoniae), 16S rDNA sequences clearly afliated with the class (Weisburg et al. 1989), unique codon usage (e.g., UGA as a tryptophan codon) in some lineages, minimal metabolic capabilities, lack of any cell wall, and species-specic serology. Although their cells are bounded only by a unit membrane, resulting in a general cellular pleomorphism, cytoskeletal elements confer helicity or polarity in some species. Some species exhibit rotatory, exional, or gliding motility. The best-studied mollicutes are signicant pathogens of humans, domesticated animals, or plants, and several species are common contaminants of in vitro eukaryotic cell cultures (Baseman and Tully 1997). Division G of the American Society for Microbiology (ASM.org) encompasses the genetic, pathogenic, immunogenic, taxonomic, biochemical, and clinical aspects of the animal, human, plant, and insect mollicutes. The International Organization for Mycoplasmology (IOM-Online.org) and its International Research Programme on Comparative Mycoplasmology promote the cooperative international
Species Concept for Mycoplasma and Related Organisms ............................................................ 580 Description of the Class Mollicutes ............................................................................................... 581
The Order Mycoplasmatales and Family Mycoplasmataceae .................................................. 581 Genus Mycoplasma .............................................................................................................. 581 Genus Ureaplasma ............................................................................................................... 582
The Order Entomoplasmatales and Families Spiroplasmataceae and Entomoplasmataceae ..... 583 Genus Spiroplasma ............................................................................................................... 583 The Genera Entomoplasma and Mesoplasma ...................................................................... 583
The Order Acholeplasmatales, Family Acholeplasmataceae, and Genus Acholeplasma ......... 584 The Order Anaeroplasmatales, Family Anaeroplasmataceae, and Genera Anaeroplasma and Asteroleplasma ........................................................................ 584 Uncultivated Mollicutes ............................................................................................................ 584 Standards for Descriptions of New Species .............................................................................. 586
Culture Media ................................................................................................................................ 586 Detection, Surveillance, Treatment, and Control ........................................................................... 587 Molecular Genetic Manipulation ................................................................................................... 593 Acknowledgments .......................................................................................................................... 597 References ...................................................................................................................................... 598
study of mycoplasmas and mollicute diseases. The purpose of this chapter is to introduce scientists who have been trained in other disciplines to Mycoplasma and related organisms, and to provide an entry to the literature of practical mycoplasmology with emphasis on vaccinology and methods of genetic manipulation for microbiologists who specialize in other species.
