Rikenella microfusus

(aka Bacteroides microfusus)

Bacteria
General | Carbohydrate O/F | Substrate utilisation | Enzymes | Metabolites | Antibiotics

Overview

  • Rikenella microfusus, (aka Bacteroides microfusus), is a Gram-negative, non-spore-forming, strictly anaerobic, non-motile, short rod-shaped bacterium. It has been detected in at least 2 gut microbiome compilation studies or metastudies. The DNA G+C content is 57.0%. Rikenella microfusus is probably a rare gut coloniser. (Collins1985; Kaneuchi1978)



  • This organism has been recovered from faecal or caecal specimens from calves, chickens, and Japanese quails. The risk classification (www.baua.de) for this organism is 1, i.e., low risk of infection and spread. Pathogenicity status unknown, or very unlikely to be pathogenic. A possible gut commensal.
    • GENERAL CHARACTERISTICS (Collins1985); (Kaneuchi1978);
    Character Response
  • Substrates hydrolysed or digested:
  • gelatin; milk;
  • 💧
  • Bile tolerance:
  • None
  • 🌡
  • Temperature tolerance:
  • doesn't grow at 25℃; grows weakly at 45℃; Grows optimally at 37℃.
  • H+
  • Acid from carbohydrates usually produced:
  • galactose; glucose; mannose; lactose; melibiose;
  • Active enzymes:
  • β-glucuronidase; glutamic acid decarboxylase;
    • SPECIAL FEATURES (Collins1985); (Kaneuchi1978);
    Character Response
  • ✓
  • Metabolites produced:
  • acetate; propionate; ethanol; succinate (major);
  • ✗
  • Metabolites not produced:
  • H₂S; ammonia; indole;
  • ✗
  • VP test:
  • not active
  • Haemolysis:
  • beta
  • ✗
  • Nitrate:
  • not reduced
    • RESPONSE TO ANTIBIOTICS (Collins1985); (Kaneuchi1978);
    Class Active Resistant
  • Penicillins:
  • penicillin;
  • Cephalosporins:
  • cephalothin;
  • Macrolides:
  • erythromycin;
  • Aminoglycosides:
  • neomycin;
  • kanamycin;
  • Polypep/ketides:
  • rifampicin;
  • bacitracin;
  • Vancomycins:
  • vancomycin;
  • Miscellaneous antibiotics:
  • colistin; polymyxin B;

    • Details

    GENERAL
    Lineage Physiology General Growth Tolerances Hydrol./digest./degr.
    Phylum:  Bacteroidetes Class:  Bacteroidia Order:  Bacteroidales Family:  Rikenellaceae Genus:  Rikenella Alt. name:  Bacteroides microfusus Gram stain:  neg O2 Relation.:  strictly anaerobic Spore:  No spore Motility:  Sessile Morphology:  Short Rod
    Health:  Unknown
    Source:  faecal or caecal specimens from calves, chickens, and Japanese quails
    DNA G+C(%):  57.0
    Opt. T:  37℃
    Lower T(℃):  25(neg)
    High T(℃):  45(w)
    Bile reaction(%):  20(R)
    		Aesculin:  neg Urea:  neg Gelatin:  + Starch:  neg Casein:  neg Milk:  +
    CARBOHYDRATE ACID FORMATION
    Monosaccharide O/F Oligosaccharide O/F Polysaccharide O/F Polyol O/F Other O/F
    Arabinose:  neg Fructose:  neg Galactose:  d(+) Glucose:  + Mannose:  + Rhamnose:  neg Ribose:  neg Sorbose:  neg Xylose:  neg Cellubiose:  neg Lactose:  + Maltose:  neg Melezitose:  neg Melibiose:  + Trehalose:  neg Amygdalin:  neg Dextrin:  neg Aesculin:  neg Glycogen:  neg Starch:  neg Dulcitol:  neg Erythritol:  neg Glycerol:  neg Inositol:  neg Mannitol:  neg Me-α-D-Glc:  neg Me-α-D-Mann:  neg Salicin:  neg
    ENZYME ACTIVITY
    Enzymes: General Enzymes: Carbohydrate Enzymes: Protein Enzymes: Arylamidases Enzymes: Esters/fats
    Catalase:  neg Urease:  neg β-Glucuronidase:  + GluDC:  + Lecithinase:  neg Lipase:  neg
    METABOLITES - PRODUCTION & USE
    Fuel Usable Metabolites Metabolites Released Special Products Compounds Produced

    		Acetate:  + Propionate:  + Ethanol:  + Succinate:  Major(+) H2S:  neg Ammonia:  neg Indole:  neg
    ANTIBIOTICS ℞
    Penicillins & Penems (μg/mL) Cephalosporins (μg/mL) Aminoglycosides (μg/mL) Macrolides (μg/mL) Quinolones (μg/mL)
    penicillin:  R(15; disc)
    cephalothin:  R(10; disc)
    kanamycin:  R(1000; disc)
    neomycin:  S(1600; disc)
    erythromycin:  R(10; disc)
    Tetracyclines (μg/mL) Vancomycin Class (μg/mL) Polypep/ketides (μg/mL) Heterocycles (μg/mL) Other (μg/mL)
    vancomycin:  R(10; disc)
    bacitracin:  R(3U)
    rifampicin:  S(15; disc)
    colistin:  R(300; disc)
    polymyxin_B:  R(10; disc)

    References

    SPECIFIC REFERENCES FOR RIKENELLA MICROFUSUS
  • Collins1985 - Reclassification of Bacteroides microfusus (Kaneuchi and Mitsuoka) in a New Genus Rikenella, as Rikenella microfusus comb. nov.
  • Kaneuchi1978 - Bacteroides microfusus, a New Species from the Intestines of Calves, Chickens, and Japanese Quails.
  • ...............................
    • GUT MICROBIOME COMPILATIONS AND METASTUDIES FOR RIKENELLA MICROFUSUS
  • Byrd2020 - Stability and dynamics of the human gut microbiome and its association with systemic immune traits.
  • Minerbi2019 - Altered microbiome composition in individuals with fibromyalgia
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    • Added: May 15, 2022