Peptidoglycan types of strains of the genus Peptococcus

The hidden base of the iceberg: gut peptidoglycome dynamics is foundational to its influence on the host

The intestinal microbiota of humans includes a highly diverse range of bacterial species. All these bacteria possess a cell wall, composed primarily of the macromolecule peptidoglycan. As such, the gut also harbors an abundant and varied peptidoglycome. A remarkable range of host physiological pathways are regulated by peptidoglycan fragments that originate from the gut microbiota and enter the host system. Interactions between the host system and peptidoglycan can influence physiological development and homeostasis, promote health, or contribute to inflammatory disease. Underlying these effects is the interplay between microbiota composition and enzymatic processes that shape the intestinal peptidoglycome, dictating the types of peptidoglycan generated, that subsequently cross the gut barrier. In this review, we highlight and discuss the hidden and emerging functional aspects of the microbiome, i.e. the hidden base of the iceberg, that modulate the composition of gut peptidoglycan, and how these fundamental processes are drivers of physiological outcomes for the host.

Complete genome sequence of Anaerococcus prevotii type strain (PC1)

Anaerococcus prevotii (Foubert and Douglas 1948) Ezaki et al. 2001 is the type species of the genus, and is of phylogenetic interest because of its arguable assignment to the provisionally arranged family 'Peptostreptococcaceae'. A. prevotii is an obligate anaerobic coccus, usually arranged in clumps or tetrads. The strain, whose genome is described here, was originally isolated from human plasma; other strains of the species were also isolated from clinical specimen. Here we describe the features of this organism, together with the complete genome sequence and annotation. This is the first completed genome sequence of a member of the genus. Next to Finegoldia magna, A. prevotii is only the second species from the family 'Peptostreptococcaceae' for which a complete genome sequence is described. The 1,998,633 bp long genome (chromosome and one plasmid) with its 1852 protein-coding and 61 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

Enrichment and isolation of Acetitomaculum ruminis, gen. nov., sp. nov.: acetogenic bacteria from the bovine rumen

Five strains of acetogenic bacteria were isolated by selective enrichment from the rumen of a mature Hereford crossbred steer fed a typical high forage diet. Suspensions of rumen bacteria, prepared from contents collected 7 h postfeeding, blended and strained through cheesecloth, were incubated in a minimal medium containing 10% clarified rumen fluid under either H2:CO2 (80:20) or N2:CO2 (80:20) headspace atmosphere. The selection criterion was an increment of acetate in the enrichments incubated under H2:CO2. Periodically, the enrichment broths were plated onto agar media and presumed acetogenic bacteria subsequently were screened for acetate production. Selected acetogenic bacteria utilized a pressurized atmosphere of H2:CO2 to form acetate in quantities 2 to 8-fold higher than when grown under N2:CO2. All presumptive acetogenic isolates were derived from either the 10(-7) or 10(-8) dilutions of rumen contents. All 5 strains were Gram-positive rods, and all utilized formate, glucose and CO. One strain required, and all were stimulated by, rumen fluid. No spores were observed with phase-contrast microscopy and two strains were motile. No methane was detected in the headspace of pure cultures grown under either gas phase. The isolation of these bacteria indicates that acetogenic bacteria are inhabitants of the rumen of the bovine fed a typical diet and suggests that they may be participants in the utilization of hydrogen in the rumen ecosystem. Strain 139B (= ATCC 43876) is named Acetitomaculum ruminis gen. nov., sp. nov. and is the type strain of this new species.

Achromopeptidase for lysis of anaerobic gram-positive cocci

Achromopeptidase, which has potent bacteriolytic activity for most of the gram-positive aerobic bacteria, was for the first time used for the lysis of anaerobic cocci. Most of the lysozyme-resistant gram-positive anaerobic cocci were lysed with this new enzyme. Peptococcus magnus was the only organism tested resistant to achromopeptidase. P. saccharolyticus was quite unusual because it was very sensitive to both achromopeptidase and lysozyme.

Individual differences in the bacterial flora of the skin of the forehead: Peptococcus saccharolyticus

Peptococcus saccharolyticus was a numerically important constituent of the bacterial flora of the forehead of 20% of 40 subjects. 16 of these subjects were studied over periods of 12 to 54 mo. It was consistently absent from 12 subjects, was present on every test of 3 subjects, and constituted 96 to 100% of the total flora on 1 subject tested 8 times in a 16-month period. On the forehead of one subject, Peptococcus saccharolyticus was recovered in only 1 of 5 tests.

Isolation and identification of Peptococcus saccharolyticus from human skin

Peptococcus saccharolyticus was a numerically important organism on the forehead and the antecubital fossa of the arm of ca. 20% of the subjects studied. It was best detected by prolonged (4- to 7-day) anaerobic incubation on a suitably enriched medium but also appeared in smaller numbers in aerobic primary cultures after 4 to 7 days. Initial screening was based on growth patterns in shake cultures and on the relative amounts of growth on aerobic and anaerobic streak plates. The organism was nonhemolytic and usually catalase positive. It produced acid anaerobically from glucose, fructose, and glycerol, but not from maltose, and did not produce lactic acid from glucose.