Outbreak of colistin-resistant, carbapenem-resistant Klebsiella pneumoniae in metropolitan Detroit, Michigan.
Carbapenem-resistant Klebsiella pneumoniae has spread worldwide and throughout the United States. Colistin is used extensively to treat infections with this organism. We describe a cluster of colistin-resistant, carbapenem-resistant K. pneumoniae infection cases involving three institutions in Detroit, MI. A cluster of five cases of colistin-resistant, carbapenem-resistant K. pneumoniae was identified at Detroit Medical Center (DMC) from 27 July to 22 August 2009. Epidemiologic data were collected, and transmission opportunities were analyzed. Isolates were genotyped by using pulsed-field gel electrophoresis and repetitive extragenic palindromic PCR. Data regarding the use of colistin were obtained from pharmacy records. The index case of colistin-resistant, carbapenem-resistant K. pneumoniae was followed 20 days later by four additional cases occurring in a 6-day interval. All of the patients, at some point, had stayed at one particular institution. The mean number of opportunities for transmission between patients was 2.3 ± 0.5, and each patient had at least one opportunity for transmission with one of the other patients. Compared to 60 colistin-susceptible, carbapenem-resistant K. pneumoniae controls isolated in the previous year at DMC, case patients were significantly older (P = 0.05) and the carbapenem-resistant K. pneumoniae organisms isolated from them displayed much higher MICs to imipenem (P < 0.001). Colistin use was not enhanced in the months preceding the outbreak. Genotyping revealed two closely related clones. This report of a colistin-resistant, carbapenem-resistant K. pneumoniae outbreak is strongly linked to patient-to-patient transmission. Controlling the spread and novel emergence of bacteria with this phenotype is of paramount importance.
Division of Infectious Diseases, Detroit Medical Center, Wayne State University, Detroit, MI 48201, USA. drormc@hotmail.com
Dror
D
Marchaim
Teena
T
Chopra
Jason M
JM
Pogue
Federico
F
Perez
Andrea M
AM
Hujer
Susan
S
Rudin
Andrea
A
Endimiani
Shiri
S
Navon-Venezia
Jatinder
J
Hothi
Jessica
J
Slim
Christopher
C
Blunden
Maryann
M
Shango
Paul R
PR
Lephart
Hossein
H
Salimnia
Deborah
D
Reid
Judy
J
Moshos
Wasif
W
Hafeez
Suchitha
S
Bheemreddy
Ting-Yi
TY
Chen
Sorabh
S
Dhar
Robert A
RA
Bonomo
Keith S
KS
Kaye
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015780:Carbapenems / Q000494:pharmacology*; D003091:Colistin / Q000494:pharmacology*; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D004196:Disease Outbreaks; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D005838:Genotype; D006785:Hospitals, University; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction
D000900:Anti-Bacterial Agents; D015780:Carbapenems; D003091:Colistin