305. Enterobacteriaceae native joint septic arthritis
Session: Poster Abstract Session: Bone and Joint Infections
Thursday, October 4, 2018
Room: S Poster Hall
  • ID Week poster Enterobacterales_poster.pdf (558.8 kB)
  • Background:

    Native joint septic arthritis (NJSA) is commonly caused by Gram positive organisms. Gram negative NJSA is uncommon, and discussion is usually limited to gonococcal arthritis despite NJSA due to enterobacteriaceae being more prevalent. We aimed to describe the clinical features, treatment and outcomes of enterobacteriaceae NJSA (ENJSA).


    Cases were obtained from a previously-described retrospective cohort of adult NJSA admitted to Middlemore Hospital, Auckland, New Zealand between 1 January 2009 and 31 December 2014. ENJSA episodes were compared to non-enterobacteriaceae NJSA (NENJSA).


    From 543 NJSA episodes identified, ENJSA were the most frequent Gram negative group (7%, 36/543) followed by HACEK (25/543), non-fermenters (10/543), Pasteurella (9/543) and Neisseria (5/543). Median age of ENJSA cases was 50 years and 72% were male. Immune compromise was more prevalent in ENJSA (19%, 7/36) than NENJSA (8%, 42/507), p=0.0341.

    The most common causative organism for ENJSA was E. coli (10/36), followed by Enterobacter cloacae (8/36) and Klebsiella pneumoniae (6/36). Polymicrobial infection was more common in ENJSA (64%, 23/36) than NENJSA (20%, 99/507), p≤0.0001.

    All ENJSA cases were monoarticular, and 72%, (26/36) affected large joints. Small joint infection was less common in ENJSA (28%, 10/36) than NENJSA (47%, 240/507), p=0.0247. Osteomyelitis was more common in ENJSA (53%, 19/36) than NENJSA (23%, 116/507), p=0.0002. Carbapenems and ciprofloxacin were the most commonly utilised antimicrobials for ENJSA.

    Clinical outcomes were worse for ENJSA, with higher rates of treatment failure (53%, 19/36) than NENJSA (15%, 76/507), p=0.0001, (though this association did not persist on multivariate analysis of the whole cohort), and longer mean length of stay (23.2 vs 12.8 days p=0.0001).


    Enterobacteriaceae are an important and poorly-described cause of NJSA, associated with immune compromise, large joint infection, polymicrobial infection, treatment failure and increased hospital length of stay. The optimal management strategy to improve ENJSA outcomes is unknown, but may include more aggressive surgical and longer medical therapy. Further studies of ENJSA are warranted.

    Boris Yow, MBChB1, Stephen McBride, BHB, MBChB2, Jessica Mowbray, MBChB3, William Caughey, MBChB3, Edbert Wong, MBChB2, Christopher Luey, MBChB1, Ahsan Siddiqui, MB BS2, Zanazir Alexander, MBChB3, Veronica Playle, MBChB1, Timothy Askelund, MBChB1, Christopher Hopkins, MD4, Norman Quek, MBChB1, Katie Ross, MBChB1 and David Holland, MBChB FRACP FRCPA PhD1, (1)Middlemore Hospital, Auckland, New Zealand, (2)Department of Medicine, Middlemore Hospital, Auckland, New Zealand, (3)Department of Surgery, Middlemore Hospital, Auckland, New Zealand, (4)Infectious Diseases, Middlemore Hospital, Auckland, New Zealand


    B. Yow, None

    S. McBride, None

    J. Mowbray, None

    W. Caughey, None

    E. Wong, None

    C. Luey, None

    A. Siddiqui, None

    Z. Alexander, None

    V. Playle, None

    T. Askelund, None

    C. Hopkins, None

    N. Quek, None

    K. Ross, None

    D. Holland, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 3rd with the exception of research findings presented at the IDWeek press conferences.