Production of Menaquinones by Intestinal Anaerobes

Abstract

Ninety intestinal organisms (71 isolates from fecal samples of neutropenic patients with cancer or from various sites in patients with intraabdominal infections and 19 control strains) were examined by reverse-phase thin-layer chromatography for their ability to produce menaquinones in vitro. Menaquinones were found in all of 24 organisms of the Bacteroides fragilis group. Two other Bacteroides species, Bacteroides disiens and Bacteroides bivius, also produced menaquinones. A single isolate of Bacteroides species lacked menaquinones. These constituents were found in all of five strains of Escherichia coli, all of four strains of Klebsiella pneumoniae, five of eight strains of Propionibacterium species, two of five strains of Eubacterium species, and the one strain each of Arachnia propionica and Veillonella parvula tested. No menaquinones were detected in organisms of the genera Fusobacterium, Clostridium, Bifidobacterium, Lactobacillus, Actinomyces, Peptococcus, or Peptostreptococcus. These findings suggest that E. coli, Bacteroides species, and some gram-positive, anaerobic, non-spore-forming bacilli produce menaquinones that may be a source of vitamin K in patients who are deprived of exogenous vitamin K1.

Gut and Root Microbiota Commonalities

“…Vitamin B 12 is an exclusive product of prokaryotes (98), and it is produced by plant root and gut bacteria (99)(100)(101)(102). Essential amino acids and vitamins B and K are produced by gut bacteria (reviewed in reference 58).…”

Microbiota conservation and BMI signatures in adult monozygotic twins

“…The microbial cells inside the human gastrointestinal (GI) tract are collectively called the GI microbiota and provide an extensive genetic function counterpart to the host genome (Savage, 1977;Albert et al, 1980;Adlercreutz et al, 1984;Ramotar et al, 1984;Cummings and Macfarlane, 1997;Cebra, 1999;Metges, 2000;Shanahan 2002;Begley et al, 2005;O'Hara et al, 2006;Wei and Brent, 2006;Yang et al, 2009). Previous studies have shown that GI microbiota is host-specific and GI tract region-specific (Zoetendal et al, 2004;Rajilic-Stojanovic et al, 2009;Jalanka-Tuovinen et al, 2011), aberrant in composition and stability in patients suffering from GI disorders such as Crohn's disease (Seksik et al, 2003), and associated to host energy homeostasis (Backhed et al, 2004;Ley et al, 2006;Turnbaugh et al, 2006;Backhed et al, 2007;Samuel et al, 2008).…”

Double-blind, prospective, multicenter trial comparing ceftazidime with moxalactam in the treatment of serious gram-negative infections

“…The search for a regimen which would be successful yet nontoxic has yielded several cephalosporins. When introduced, moxalactam appeared to be effective in this niche; however, it is not active against many strains of P. aeruginosa and is associated with prolongation of PT in some patients (2,4,12,15).…”

“…Ceftazidime is a promising cephalosporin with excellent in vitro activity against many such strains (3,16). Furthermore, therapy with ceftazidime has not been associated with bleeding and prolongation of prothrombin time (PT), as has occurred with moxalactam (2,4,12,15).…”