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Allisonella histaminiformansRANK: SpeciesTAXONOMY: Terrabacteria group -> Firmicutes -> Negativicutes -> Selenomonadales -> Veillonellaceae -> Allisonella -> Allisonella histaminiformans OVERVIEW: Identified as constituent of vaginal microbiome. [PMID:23282177] Obligate histidine-decarboxylating bacterium. The growth of A. histaminiformans was stimulated by yeast extract, protein hydrolysates, and water-soluble extracts of alfalfa or corn silage. Extracts of alfalfa were more potent than corn silage. Because growth and histamine production were not stimulated by Casamino Acids or a mixture of purified amino acids, it appeared that A. histaminiformans requires peptides. The idea that A. histaminiformans requires peptides is consistent with the observation that alfalfa silages often have a large amount of peptide nitrogen. The cells stained Gram-negative and were resistant to the ionophore, monensin (25 microM). The doubling time was 110 min, and the yield was 1.5 mg cell protein per mmol histidine. The G+C content was 46.8%. Lysine was the only other amino acid used, but lysine did not allow growth if histidine was absent. Because carbohydrate and organic acid utilization was not detected, it appeared that the isolates used histidine decarboxylation as their sole mechanism of energy derivation. 16s rRNA gene sequencing indicated that the isolates were most closely related to low G+C Gram-positive bacteria (firmicutes), but similarities were < or = 94%. This species has been identified as a resident in the human gastrointestinal tract based on the phylogenetic framework of its small subunit ribosomal RNA gene sequences.[PMC 4262072]
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