Classification of Micrococci on the Basis of Deoxyribonucleic Acid Homology

Abstract

S U M M A R YThe DNA homology relationships of 25 micrococci (15 strains of Micrococcus, eight strains of Sarcina and two strains of Staphylococcus) were studied by the deoxyribonucleic acid hybridization method using nuclease S,, an endonuclease specific for single-stranded DNA molecules. Nineteen of the strains were classified into three groups. De Ley et al., 1973). The DNA hybridization method using nitrocellulose membranes is common today, but this method has the disadvantage that DNA fixed on nitrocellulose membranes is released during incubation at high temperatures (Okanishi & Gregory, I 9 7 0 ) . Recently, nuclease S, isolated from Aspergillus oryzae, which is specific for single-stranded nucleic acid (Ando, I 966), was successfully used in improving the nitrocellulose-membrane DNA hybridization method. This endonuclease digests only the single-stranded DNA portion that has not hybridized. Crosa, Brenner & Falkow (I 973) studied the nucleotide sequence relatedness between homologous and heterologous chromosomal and plasmid DNA by the DNA hybridization method with nuclease S, and showed that this method permitted an accurate, reproducible and rapid determination of the extent of polynucleotide sequence homology. In this study, we examined the DNA homology relationships, by DNA hybridization followed by nuclease S, digestion, among species of the genus Micrococcus, including aerobic Sarcina strains which had been proved to belong to the genus Micrococcus by Kocur & Martinec (1965) and Hubalek (1969). 7-2

Drug sensitivity and clinical impact of members of the genus Kocuria

“…Owing to misidentification by phenotypic typing over the years, clinical syndromes caused by these agents are believed to be rare; however, the prevalence of such infectious pathologies is presumably higher and will surely increase in the coming years, as soon as genome-based identification is available in clinical laboratories. Accordingly, drug resistances and the clinical impact of the genus have been poorly discussed in the literature so far; therefore, the present review tries to shed light on this emerging field in medical microbiology (Takarada et al, 2008;Zhou et al, 2008;Lee et al, 2009;Li et al, 2006;Kim et al, 2004;Ma et al, 2005;Boudewijns et al, 2005;Stackebrandt et al, 1995;Reddy et al, 2003;Schleifer & Kandler, 1972;Collins et al, 1977;Dunphy et al, 1971;Rosenthal & Dziarski, 1994;Bohácek et al, 1969;Ogasawara-Fujita & Sakaguchi, 1976;Staneck & Roberts, 1974;Becker et al, 2008;Kovács et al, 1999;Park et al, 2010a, b;Tang et al, 2009;Yun et al, 2010;Seo et al, 2009).…”

Taxonomic Dissection of the Genus Micrococcus: Kocuria gen. nov., Nesterenkonia gen. nov., Kytococcus gen. nov., Dermacoccus gen. nov., and Micrococcus Cohn 1872 gen. emend.

“…Therefore, the phylogenetic depth and width of these two genera and of the Arthrobacter line of descent within the subphylum of actinomycetes had not been fully explored. Early comparative chemotaxonomic analyses (9, 11-13, 34, 53), a genetic analysis (20), and determinations of levels of DNA-DNA similarity (35,44) also did not include all of the valid species known today. Although the previous phylogenetic studies included only micrococci, these studies led to the following taxonomic rearrangements: certain radiation-resistant red micrococci were transferred to the genus Deinococcus (2); Micrococcus muciluginosus was reclassified as Stomatococcus mucilaginosus (1); and Micrococcus agilis was found to be a phylogenetic member of the "Arthrobacrer globiformis-Arthrobacter citreus group" (sensu Keddie and Jones [19]), and as this species also had chemotaxonomic properties in common with its nonmicrococ-cal relatives, Koch and Stackebrandt proposed that it should be redescribed as Arthrobacter agilis (24).…”