Delimiting the genus Staphylococcus through description of Macrococcus caseolyticus gen. nov., comb. nov. and Macrococcus equipercicus sp. nov., Macrococcus bovicus sp. nov. and Macrococcus carouselicus sp. nov.

Abstract

Delimiting the genus. nov., are described on the basis of a phylogenetic analysis comparing 165 rRNA sequences, DNA-DNA liquid hybridization, DNA base composition, normalized ribotype patterns, macrorestriction pattern analysis and estimation of genome size using PFGE, cell wall composition, phenotypic characteristics and plasmid profiles. Compared with their closest relatives, members of the genus Staphylococcus, these organisms demonstrated significantly lower 165 rRNA sequence similarities (934-9503 %), higher DNA G+C content (38-45 mol YO), absence of cell wall teichoic acids (with the possible exception of M. caseolyticus), unique ribotype pattern types and macrorestriction patterns, smaller genome size (approx. 1500-1800 kb) and generally larger Gram-stained cell size (14-205 pm in diameter). Macrococci can be distinguished from most species of staphylococci (except Staphylococcus sciuri, Staphylococcus witulus and Staphylococcus lentus) by their oxidase activity. The four Macrococcus species can be distinguished from one another on the basis of DNA-DNA hybridization, ribotype pattern types, macrorestriction patterns and their phenotypic properties, including colony morphology, cell morphology, haemolysins, Staph Latex agglutination, acid production from a variety of carbohydrates, acetoin production, nitrate reduction, aesculin hydrolysis, and DNase and urease activities. The type species is M. equipercicus. The type strains of M. equipercicus, M. caseo/yticus, M. bovicus and M. carouselicus are ATCC 5183IT ( (Schleifer et al., 1982). These strains were isolated from the milk of cattle, but more recently several strains have been isolated from the abscesses of slaughtered lambs (De La Fuente et al., 1992) and one from the milk of goats (De Buyser et al., 1992).In a preliminary investigation (Ballard et al., 1995), we sampled the skin of 15 cattle, 25 goats, 14 horses, 10 ponies, 4 whales, 25 dolphins and meat products for the presence of Staphylococcus caseolyticus. This species was isolated from only three samples of raw beef and the skin of a pilot whale and so can still be thought of as a relatively uncommon species. Surprisingly, we discovered a group of three new species related to Staphylococcus caseolyticus living on the skin of cattle, horses and ponies. Phenotypic characterization. The following characteristics were determined as described previously Kloos et al., 1976; Webster et al., 1994;: Gram-stained cell morphology and cell arrangement, colony morphology and pigmentation, motility, anaerobic growth in thioglycollate semi-solid medium, catalase activity, acetylmethylcarbinol (acetoin) production, nitrate reduction, oxidase activity, pyrrolidonylarylamidase activity, aesculin hydrolysis, DNase activity, thermonuclease activity, ornithine decarboxylase activity, urease activity, staphylocoagulase activity, lysostaphin susceptibility, haemolysis of sheep, bovine and horse blood, and carbohydrate reactions. The presence of clumping factor and/or protein A was tested using the Staph Latex Kit ...

Identification of Staphylococcus spp. by PCR-Restriction Fragment Length Polymorphism of gap Gene

“…1A, lane 15). These results agree with the new taxonomic situation of S. caseolyticus, which has recently been reclassified as Macrococcus caseolyticus (19).…”

Rapid and Accurate Species-Level Identification of Coagulase-Negative Staphylococci by Using the sodA Gene as a Target

“…This analysis revealed that all the strains studied produce a single band of SOD activity ( Fig. 1 and data not (13). A single amplification product having the expected size of 480 bp was observed with all staphylococcal species (data not shown).…”

rpoB Gene Sequence-Based Identification of Staphylococcu s Species

“…The 16S rDNA sequence-derived trees (40,41) gave different results, however, with 12 genogroups being identified. In fact, it has been shown that S. caseolyticus should be reclassified as Macrococcus caseolyticus (20), thus limiting the number of 16S rDNA gene sequence-derived genogroups.…”

“…The position of the organism should be regarded as uncertain, however, as low bootstrap values (Յ50%) were obtained in studies of the bacteria using 16S rDNA (41) and hsp60 (20) sequence data. The rpoB-derived data indicating that S. cohnii is outside the S. saprophyticus group and closely related to S. aureus are in disagreement with previously published data and may be incorrect.…”