Transfer of Peptococcus indolicus, Peptococcus asaccharolyticus, Peptococcus prevotii, and Peptococcus magnus to the Genus Peptostreptococcus and Proposal of Peptostreptococcus tetradius sp. nov.

Abstract

The guanine-plus-cytosine (G + C) contents of the deoxyribonucleic acids (DNAs) of Peptococcus asaccharolyticus ATCC 14963T (T = type strain), Peptococcus indolicus ATCC 29427 ', Peptococcus prevotii ATCC 9321T, and Peptococcus magnus ATCC 15794T ranged from 29 to 34 mol%, whereas the G+C content of the DNA of P eptococcus niger ATCC 27731T, the type species of the genus Peptococcus, is 51 mol%. The G+C content of the DNA of Peptostreptococcus anaerobius ATCC 27337T, the type species of the genus Peptostreptococcus, was 33 mol%. Thus, the DNA base compositions of Peptococcus asaccharolyticus, Peptococcus indolicus, Peptococcus prevotii, and Peptococcus magnus resemble the DNA base composition of the type species of the genus Peptostreptococcus rather than the DNA base composition of the type species of the genus Peptococcus. It is not desirable for the genus Peptococcus to include any species whose G+C content is far from the G+C content of the type species of the genus. The levels of DNA-DNA homology between Peptostreptococcus anaerobius ATCC 27337T and the four species of Peptococcus with low G+C DNA contents ranged from 23 to 36%. The cellular fatty acid profiles of Pep tococcus asaccharolyticus, Peptococcus indolicus, Peptococcus prevotii, and Peptococcus magnus also resembled the cellular fatty acid profile of the type species of Peptostreptococcus. Other biochemical characteristics of these species revealed their close resemblance to Peptostreptococcus anaerobius. For these reasons we propose transfer of the four Peptococcus species that have low G + C contents to the genus Peptostreptococcus as Peptostreptococcus asaccharolyticus (Distaso 1912) comb. nov., P eptostreptococcus indolicus (Christiansen 1934) comb. nov., Peptostreptococcus prevotii (Foubert and Douglas 1948) comb. nov., and Peptostreptococcus mangus (Prkvot 1933) Smith 1957 comb. rev. A group of organisms previously referred to as "Gamya anaerobia" (Choukevitch) Prevot is an identifiable Peptostreptococcus species based on phenotypic and genotypic characteristics. The name of Peptostreptococcus tetradius sp. nov. is proposed for this group of organisms. Strain GIFU 7672 (= ATCC 35098) is designated the type strain. Clinical strains of P. asacchurolyticus that were identified by conventional methods were divided into two homology groups and one unclassified group (A-1). DNA-DNA homology between the type strain of P. prevotii and clinical strains which had been received as P . prevotii ranged from 0 to 73%.

Identification of gram-positive anaerobic cocci by use of systems for detecting pre-formed enzymes

“…prevotii and Ps. tetradius by Ezaki's classification (Ezaki et al, 1983). One indolepositive coccus could not be identified fully by standard methods, but was identified as Ps.…”

“…Their taxonomy was previously based on gas-liquid chromatography (GLC) of fatty-acid metabolic products and carbohydrateutilisation tests (Holdeman et al, 1977), but most GPAC have very little or no saccharolytic activity (Ezaki and Yabuuchi, 1985). Recent attempts to provide a more satisfactory classification have been based on the homology groups and guanine-pluscytosine content of the DNA (Ezaki et al, 1983;Huss et al, 1984), GLC analysis of cell fatty acids and metabolic products (Lambert et al, 1979), and analysis of cell-wall structure (Weiss, 1981). However, they have provided conflicting data and it is not surprising that little effort is made to identify isolates of GPAC in most clinical laboratories.…”

Fluorometric Deoxyribonucleic Acid-Deoxyribonucleic Acid Hybridization in Microdilution Wells as an Alternative to Membrane Filter Hybridization in which Radioisotopes Are Used To Determine Genetic Relatedness among Bacterial Strains

“…We prepare microdilution plates in which reference DNAs of medically important bacteria are fixed, and the plates are stored under dry conditions (8). When an unknown organism is isolated, its DNA is extracted from 1 to 3 ml of an overnight culture broth by using a small-scale DNA extraction method (15).…”

“…DNAs of bacterial strains (Table 1) were prepared by the procedures of Marmur, with minor modifications (8). Under optimal conditions, 100-pl portions of a heat-denatured, purified reference DNA solution (20 pg of DNA per ml) in * Corresponding author.…”

Lactobacillus equigenerosi sp. nov., a coccoid species isolated from faeces of thoroughbred racehorses

“…Extraction and isolation of bacterial DNAs were performed by the method of Marmur (1961) as modified by Ezaki et al (1983). Strains of L. fermentum, L. ingluviei and L. mucosae were not used for the determination of DNA-DNA relatedness because the sequence similarities between the isolates and the type strains of these three species were lower than the recommended value for species differentiation described by Stackebrandt & Goebel (1994).…”