Elizabeth P. Cato

Some current concepts in intestinal bacteriology

Quantitative studies of the fecal flora of populations at different risk of colon cancer indicate that the relative proportions of some particular species of bacteria rather than of different genera of bacteria may be correlated with colon cancer incidence. Since the metabolic activity of different species in each genus varies widely, a shift in proportions of species could cause a major change in total metabolic activity in the individual. In samples taken from various areas of the intestinal tract and in scrapings from the intestinal wall, the composition of the flora remained relatively constant from the ascending colon to the rectum. Therefore, the bacteria in feces do reflect the flora of the large colon. The composition of the flora was not significantly affected by drastic changes in diet, but statistically significant shifts in the proportions of some species were noted in individuals under conditions of anger or fear stress. Although diet may not change the flora the individual maintains, the bacteria present may convert the different substrates provided by a high-fat diet as opposed to a high-fiber diet into metabolites that are potentially carcinogenic. The conversion of dietary components to carcinogenic compounds, identification of the bacteria capable of effecting such conversions, and the conditions favoring the proliferation of such bacteria will be investigated in greater detail.

Taxonomy and Phylogeny

Bacterial taxonomy is the science that makes logical and rational communication possible among all scientists, microbiologists, physicians, biochemists, and others; indeed, all people who need to know and use microbiological information. Combining, as it does, the arts of classification and identification with stringent rules of nomenclature, there is much that remains subjective in the selection of limits allowed in defining each taxon. However, with the explosion of information that is accumulating regarding the chemical and genetic composition of bacterial cells, it is now becoming possible to approach the definition of limits so as to include in a taxon, at the level of either genus or species, only organisms that are truly closely related.

Reinstatement of Species Rank for Bacteroides fragilis, B. ovatus, B. distasonis, B. thetaiotaomicron, and B. vulgatus: Designation of Neotype Strains for Bacteroides fragilis (Veillon and Zuber) Castellani and Chalmers and Bacteroides thetaiotaomicron (Distaso) Castellani and Chalmers

The organisms currently recognized as subspecies of Bacteroides fragilis have been shown to be genetically distinct. Species rank is therefore restored to these organisms, and type or neotype strains have been selected for the five species described. ATCC 25285 (= NCTC 9343) is designated the neotype strain of Bacteroides fragilis (Veillon and Zuber) Castellani and Chalmers; ATCC 29184 (= strain Werner E50 = NCTC 10582) is designated the neotype strain of Bacteroides thetaiotaomicron (Distaso) Castellani and Chalmers; ATCC 8503 is designated the type strain of Bacteroides distasonis Eggerth and Gagnon; ATCC 8483 is designated the type strain of Bacteroides ovatus Eggerth and Gagnon; and ATCC 8482 is designated the type strain of Bacteroides vulgatus Eggerth and Gagnon. Characteristics of these strains are presented.

Descriptions of Eubacterium timidum sp. nov., Eubacterium brachy sp. nov., and Eubacterium nodatum sp. nov. Isolated from Human Periodontitis

Three new species of Eubacterium, E. timidum, E. brachy, and E. nodatum, which were isolated principally from subgingival areas associated with periodontitis, are described. All are anaerobic, gram-positive, non-saccharolytic rods. They are differentiated from each other and from other non-saccharolytic species of eubacteria by acid and gas products in broth cultures and by morphological and growth characteristics. The type strains for the species are as follows: E. timidum ATCC 33093; E. brachy, ATCC 33089; and E. nodatum, ATCC 33099. These species were detected in 35 to 42% of the subgingival samples examined and, where present, constituted 3 to 57% of the cultivable flora. Strains of these species were isolated only occasionally from the adjacent supragingival areas sampled.

Index of the Bacterial and Yeast Nomenclatural Changes Published in the International Journal of Systematic Bacteriology Since the 1980 Approved Lists of Bacterial Names (1 January 1980 to 1 January 1985)

The following list includes the official nomenclature of bacteria and yeasts recognized by the International Committee on Systematic Bacteriology as published or validated in the International Journal of Systematic Bacteriology (IJSB) according to the International Code of Nomenclature of Bacteria (ICNB), Rule 27. References to nomenclature established by the 1980 Approved Lists of Bacterial Names are designated by (AL). Except where noted, all references pertain to IJSB. References to original refereed articles published in IJSB are marked with an asterisk (*). References to names that appear only on validation lists give only the year, volume, and page number without special designations. The validity of species is not guaranteed by inclusion in these lists. However, the priority of the name is established by the date and page of publication in IJSB either as an original article or by mention in the validation lists (ICNB Rule 27). As far as possible, the citations of names are in the correct format according to the code and may differ from those used by the original authors. Basonyms are included to clarify the previous names or histories of individual taxa. Annotations are made to clarify the rules or rationale for some of the nomenclatural changes in this index. We would appreciate factual information concerning any errors or corrections for this list. Abbreviations and addresses of collections from which designated type strains are available (ICNB Recommendation 30A) are listed alphabetically at the end of the list. We thank Bobbie Brandon of the American Type Culture Collection for helping to provide complete addresses for the culture collections. Reprints of this publication are available for

Fermentation Patterns of some Clostridium Species.

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Synonymy of Strains of "Lactobacillus acidophilus" Group A2 (Johnson et al. 1980) with the Type Strain of Lactobacillus crispatus (Brygoo and Aladame 1953) Moore and Holdeman 1970

SUMMARY The present study of the fermentation characteristics of 20 species of clostridia has shown that the relative proportions and concentrations of the acids and alcohols produced by these cultures may be very useful in their characterization and identification. The chromatographic methods described are rapid and the patterns are highly reproducible among strains of the same species.

Fusobacterium alocis sp. nov. and Fusobacterium sulci sp. nov. from the Human Gingival Sulcus

The type strain of Lactobacillus crispatus (VPI 3199, parent strain of strain ATCC 33820) and the deoxyribonucleic acid homology reference strain of “Lactobacillus acidophilus” group A2 (strain ATCC 33197) have 100% deoxyribonucleic acid homology. L. crispatus and strains in “L. acidophilus” group A2 also produce similar polyacrylamide gel electrophoresis patterns of soluble cellular proteins and are similar in other phenotypic characteristics. Therefore, the group A2 strains are members of the species L. crispatus (Brygoo and Aladame 1953) Moore and Holdeman 1970.

Eubacterium aerofaciens (Eggerth) Prévot 1938: Emendation of Description and Designation of the Neotype Strain

Two new species, Fusobacterium alocis and Fusobacterium sulci, are described. They were isolated principally from subgingival areas associated with gingivitis or periodontitis. Strains of these species were nonreactive in the biochemical tests usually used and were differentiated most readily from each other and from other Fusobacterium species by patterns of soluble cellular proteins determined by polyacrylamide gel electrophoresis. The type strains of the species are F. alocis ATCC 35896 and F. sulci ATCC 35585.

Designation of Neotype Strains for Bacteroides amylophilus Hamlin and Hungate 1956 and Bacteroides succinogenes Hungate 1950

ATCC 25559 (Prevot strain 1899B; VPI 0255) is designated as the neotype strain of Eubacterium lentum (Eggerth) Prevot 1938; a description of this strain is given. This strain conforms to the original description of this organism by Eggerth based on 23 strains from human feces. An emended description of E. lentum is given on the basis of a study of 53 strains, including 38 recent isolates, mostly from human infections, and 3 strains labeled E. lentum from the Prevot collection.