title: Augmented production of extracellular superoxide by blood isolates of Enterococcus faecalis.
abstract: To assess the frequency of extracellular superoxide (O-2) production by enterococci, multiple species were surveyed in a whole organism assay for their ability to reduce ferricytochrome c in a superoxide dismutase-inhibitable fashion. For stool and clinical enterococcal isolates and 12 type strains, only Enterococcus faecalis (87/91 isolates and ATCC 19433), Enterococcus faecium (5/13 isolates), Enterococcus casseliflavus (ATCC 25778), and Enterococcus gallinarum (ATCC 35038) produced extracellular O-2. Among 106 strains comprising 13 species of enteric gram-negative bacilli and gram-positive cocci, only Lactococcus lactis subspecies lactis produced extracellular O-2. Mean (+/-SE) rates of extracellular O-2 production in vitro by E . faecalis for isolates associated with bacteremia and endocarditis and for isolates from stool were 2.4+/-0.2, 1.9+/-0.2, 1.5+/-0.3 nmol of O-2 min(-1) 10(9) cfu(-1), respectively (P=.025, analysis of variance), suggesting an association between invasiveness and extracellular O-2 production.
authors.affiliation: Department of Veterans Affairs Medical Center, Oklahoma City, 73104, USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Huycke
authors.forename: W
authors.initials: W
authors.lastname: Joyce
authors.forename: M F
authors.initials: MF
authors.lastname: Wack
mesh_terms: D016470:Bacteremia / Q000382:microbiology*; D004697:Endocarditis, Bacterial / Q000382:microbiology; D013293:Enterococcus faecalis / Q000302:isolation & purification / Q000378:metabolism* / Q000472:pathogenicity; D005110:Extracellular Space / Q000378:metabolism; D005243:Feces / Q000382:microbiology; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D006801:Humans; D066298:In Vitro Techniques; D013294:Lactococcus lactis / Q000378:metabolism; D011552:Pseudomonas Infections / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*; D014774:Virulence
chemical_list: D013481:Superoxides