Molecular and epidemiological characterization of IMP-type metallo-β-lactamase-producing Enterobacter cloacae in a Large tertiary care hospital in Japan.
IMP-type metallo-β-lactamase enzymes have been reported in different geographical areas and in various Gram-negative bacteria. However, the risk factors and epidemiology pertaining to IMP-type metallo-β-lactamase-producing Enterobacter cloacae (IMP-producing E. cloacae) have not been systematically evaluated. We conducted a retrospective, matched case-control study of patients from whom IMP-producing E. cloacae isolates were obtained, in addition to performing thorough molecular analyses of the clinically obtained IMP-producing E. cloacae isolates. Unique cases with IMP-producing E. cloacae isolation were included. Patients with IMP-producing E. cloacae were matched to uninfected controls at a ratio of 1 to 3. Fifteen IMP-producing E. cloacae cases were identified, with five of the isolates being obtained from blood, and they were matched to 45 uninfected controls. All (100%) patients from whom IMP-producing E. cloacae isolates were obtained had indwelling devices at the time of isolation, compared with one (2.2%) uninfected control. Independent predictors for isolation of IMP-producing E. cloacae were identified as cephalosporin exposure and invasive procedures within 3 months. Although in-hospital mortality rates were similar between cases and controls (14.3% versus 13.3%), the in-hospital mortality of patients with IMP-producing E. cloacae-caused bacteremia was significantly higher (40%) than the rate in controls. IMP-producing E. cloacae isolates were frequently positive for other resistance determinants. The MICs of meropenem and imipenem were not elevated; 10 (67%) and 12 (80%) of the 15 IMP-producing E. cloacae isolates had a MIC of ≤ 1 μg/ml. A phylogenetic tree showed a close relationship among the IMP-producing E. cloacae samples. Indwelling devices, exposure to cephalosporin, and a history of invasive procedures were associated with isolation of IMP-producing E. cloacae. Screening for carbapenemase production is important in order to apply appropriate clinical management and infection control measures.
Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan kayokohayakawa@gmail.com.
Kayoko
K
Hayakawa
Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
Tohru
T
Miyoshi-Akiyama
Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
Teruo
T
Kirikae
Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
Maki
M
Nagamatsu
Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
Kayo
K
Shimada
Microbiology Laboratory, National Center for Global Health and Medicine, Tokyo, Japan.
Kazuhisa
K
Mezaki
Infection Control and Prevention, National Center for Global Health and Medicine, Tokyo, Japan.
Yuko
Y
Sugiki
Infection Control and Prevention, National Center for Global Health and Medicine, Tokyo, Japan.
Emi
E
Kuroda
Infection Control and Prevention, National Center for Global Health and Medicine, Tokyo, Japan.
Shiho
S
Kubota
Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan.
Nozomi
N
Takeshita
Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan.
Satoshi
S
Kutsuna
Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan.
Masayoshi
M
Tojo
Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan.
Norio
N
Ohmagari
D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002511:Cephalosporins / Q000627:therapeutic use; D016972:Enterobacter cloacae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*; D004756:Enterobacteriaceae Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D015378:Imipenem / Q000627:therapeutic use; D017053:Infection Control; D007291:Inosine Monophosphate; D007564:Japan / Q000453:epidemiology; D008297:Male; D000077731:Meropenem; D008875:Middle Aged; D010802:Phylogeny; D011815:R Factors; D012189:Retrospective Studies; D012307:Risk Factors; D063128:Tertiary Health Care; D013845:Thienamycins / Q000627:therapeutic use; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
D001426:Bacterial Proteins; D002511:Cephalosporins; D013845:Thienamycins; D007291:Inosine Monophosphate; D015378:Imipenem; D001618:beta-Lactamases; C063912:carbapenemase; D000077731:Meropenem