Holdemania filiformis

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A Microbial Biorealm page on the genus Holdemania filiformis

Higher order taxa

Domain: Bacteria, Phylum: Firmicutes, Subphylum: Clostridium, Class: Erysipelotrichia, Order: Erysipelotrichales, Family: Erysipelotrichaceae

Genus, Species

Holdemania filiformis

Description and significance

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Holdemania filiformis is a Gram-positive bacterium found in the gut of healthy humans. It is rod shaped and exists in pairs and short chains. Cells can be short or long (numerical measurements are currently unavailable), with longer cells possibly exhibiting central or terminal swellings. It has not been observed to be spore forming or heat resistant. At present, filiformis is the only species in the genus Holdemania.¹ The amount existing in the gut and the effects of its presence is unknown. It is resistant to vancomycin.²

Genome structure

H. filiformis has a single circular chromosome consisting of 3,932,923 base pairs⁵, as submitted to the National Center for Biotechnology Information (NCBI) on December 19th, 2008 by the Genome Sequencing Center at Washington University School of Medicine.⁶ The genome was sequenced using shotgun assembly. 4223 hypothetical protein coding regions have been recognized.⁷ Some exampes may be found here.⁴

Cell and colony structure

Diagram of unique interpeptide bridge (boxed).²

H. filiformis is a Gram positive-staining bacterium that easily decolorizes. The cell wall contains a group B murein type (B1δ(L-Ala)-D-Glu-L-Asp-L-Lys) that has not been observed in any other bacterial species.¹ Colonies grown on brain heart infusion agar are 1.0 mm in diameter. They are circular, entire, low convex, and translucent with a granular appearance. PYT-glucose broth cultures were turbid and contained white sediment.²

Metabolism

Strictly anaerobic.² It is saccharolytic. Good growth was exhibited in PYT broth media containing esculin, fructose, glucose, salicin, or sucrose. Moderate growth can sometimes be observed in peptone-yeast extract broth with maltose or lactose. Minimal growth was seen in PYT broths with no carbohydrates or with amydalin, arabinose, cellobiose, erythritol, glycogen, inositol, mannitol, mannose, melzitose, melibiose, raffinose, rhamnose, ribose, sorbitol, starch, trehalose, or xylose. In PYT-glucose broth, the consistent end products of fermentation were acetic acid, lactic acid, and succinic acid.² Meat, gelatin, and milk are not digested or changed. Esculin is hydrolyzed; nitrate is not reduced; arginine is not deanimated; catalase and indole are not produced. It has been shown to grow in media ranging from a pH of 5.8 to 6.5 ^1,2 consistent with ranges found in the human large intestine.

Ecology

H. filiformis is part of the normal human gut flora. It was originally isolated from human feces.² It appears to be mesophilic.

Pathology

H. filiformis has not been observed to be pathogenic.²

References

1 Dos, P. D., Garrity, G. M., Jones, D., Krieg, N. R., Ludwig, W., Rainey, F. A., Schleifer, K., Whitman, W. B., Parte, A. C., Goodfellow, M. 2009 Bergey’s manual of systematic bacteriology. Volume three, the firmicutes. Dordrecht, NY 1417 pp. doi# 10.1007/b92997

2 Willems, A., Moore, W. E. C., Weiss, N., Collins, M. D. 1997. Phenotypic and Phylogenetic Characterization of some Eubacteriurn-like isolates containing a novel type B wall murein from human feces: description of Holdemania filiformis gen. nov., sp. nov. International J. of Systematic Bacteriolol.47: 1201-1204 doi# 10.1099/00207713-47-4-1201

3 Holdemani filiformis overview. http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=61171&lvl=3&lin=f&keep=1&srchmode=1&unlock May 2, 2012

4Holdemania filiformis peptidase or homologue coding regions. http://merops.sanger.ac.uk/cgi-bin/speccards?sp=sp019394;type=P May 3 2012

5Holdemania filiformis overview: Genome. http://www.ncbi.nlm.nih.gov/genome/2036 May 2, 2012

6Holdemania filiformis master record for whole genome shotgun sequencing. http://www.ncbi.nlm.nih.gov/nuccore/223965545 May 2, 2012

7 Holdemania filiformis reference genome for the Human Microbiome Project. http://www.ncbi.nlm.nih.gov/bioproject/30361 May, 2, 2012

Edited by a student of Dr. Lisa R. Moore, University of Southern Maine, Department of Biological Sciences, http://www.usm.maine.edu/bio