1264. Human Infections due to Aerococcus species
Session: Poster Abstract Session: Bacteremia and Endocarditis
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
  • Aerococcus IDSA poster 9-25-2013.gif (365.1 kB)
  • Background: Aerococcus species may be isolated from urine, blood or other sources.  Previous studies have focused on isolates from particular sources, especially urine, or individual Aerococcus species.  We now report a large case series based on all cultures positive for an Aerococcus from any source at 3 large hospitals in Houston, TX. 

    Methods: Electronic reports of all cultures yielding Aerococcus species from 2002-2012 were obtained from Houston VA Medical Center, Ben Taub General Hospital and St. Luke’s Episcopal Hospital. We performed in depth review of medical records.  Cases of bacteremia were stratified into definite bacteremia, probable bacteremia, and possible contaminant.  For bacteriuria, cases were stratified into symptomatic urinary tract infection (UTI) and asymptomatic bacteriuria (ASB).

    Results: Aerococcus was isolated from 93 patients.  Aerococcus was isolated from blood of 64 patients including 3 with endocarditis, 7 with UTI, and 5 with other infections (definite), 14 with probable bacteremia and 35 in which Aerococcus was determined to be a possible contaminant.  Of 19 urine isolates, 10 were from patients with symptomatic UTI and 7 were from patients with ASB; in 2 cases, the urine isolates were regarded as a possible contaminant.   Most patients with UTI had underlying urological abnormalities. Other sources for Aerococcus included synovial fluid, bile, bone, intra-abdominal abscess and ovarian abscess.  Of 57 isolates that were speciated, 44 were A. viridans and 13 were A. urinae. All isolates tested with ampicillin, cefazolin, clindamycin and vancomycin were susceptible.  Individual isolates were resistant to penicillin, tetracycline, ciprofloxacin and TMP/SMX. In all, 4 patients with Aerococcus infection died but all others responded to antibiotic therapy. 

    Conclusion: Aerococcus is often considered a contaminant but in our review 23-45% of blood isolates and 40% of all isolates were implicated in a range of human infections, often together with other organisms.  Individual isolates had varying resistance patterns. Appropriate attention needs to be given to Aerococcus, especially when it is isolated from a normally sterile site or from the urine, and antibiotic susceptibility testing is needed to guide therapy.

    Kosuke Yasukawa, MD1,2, Zeeshan Afzal, MD1, Pamela Mbang, MD1, Charles Stager, PhD1 and Daniel Musher, MD, FIDSA2, (1)Michael E. Debakey VA Medical Center, Houston, TX, (2)Baylor College of Medicine, Houston, TX


    K. Yasukawa, None

    Z. Afzal, None

    P. Mbang, None

    C. Stager, None

    D. Musher, None

    Findings in the abstracts are embargoed until 12:01 a.m. PST, Oct. 2nd with the exception of research findings presented at the IDWeek press conferences.