Invasive Klebsiella pneumoniae Infections, California, USA

摘要

To the Editor: A distinctive form of tissue-invasive community-associ-ated Klebsiella pneumoniae infection, typifi ed by primary liver abscess and bacteremia, has been well known in Asia for 2 decades (1–4). Association of these infections with a hypermu-coviscous phenotype was discovered in 2004 (5). Certain genetic and viru-lence features were elucidated in that and subsequent reports (6).The phenotype, easily detected at the bench by the string test (5), has been associated with a chromosomal gene, the mucoviscosity-associated gene A (magA), and a plasmid gene, the regu-lator of the mucoid phenotype A gene (rmpA). Usually serotypes K1 and K2 can be demonstrated. Hypermucovis-cous isolates demonstrate increased virulence in mice, are serum insensi-tive, and resist phagocytosis (5).