Colistin Resistance in Carbapenem-Resistant Klebsiella pneumoniae: Laboratory Detection and Impact on Mortality.
Published
Journal Article
Background: Polymyxins including colistin are an important "last-line" treatment for infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKp). Increasing use of colistin has led to resistance to this cationic antimicrobial peptide. Methods: A cohort nested within the Consortium on Resistance against Carbapenems in Klebsiella pneumoniae (CRACKLE) was constructed of patients with infection, or colonization with CRKp isolates tested for colistin susceptibility during the study period of December, 2011 to October, 2014. Reference colistin resistance determination as performed by broth macrodilution was compared to results from clinical microbiology laboratories (Etest) and to polymyxin resistance testing. Each patient was included once, at the time of their first colistin-tested CRKp positive culture. Time to 30-day in-hospital all-cause mortality was evaluated by Kaplan-Meier curves and Cox proportional hazard modeling. Results: In 246 patients with CRKp, 13% possessed ColR CRKp. ColR was underestimated by Etest (very major error rate = 35%, major error rate = 0.4%). A variety of rep-PCR strain types were encountered in both the ColS and the ColR groups. Carbapenem resistance was mediated primarily by blaKPC-2 (46%) and blaKPC-3 (50%). ColR was associated with increased hazard for in-hospital mortality (aHR 3.48; 95% confidence interval, 1.73-6.57; P < .001). The plasmid-associated ColR genes, mcr-1 and mcr-2 were not detected in any of the ColR CRKp. Conclusions: In this cohort, 13% of patients with CRKp presented with ColR CRKp. The apparent polyclonal nature of the isolates suggests de novo emergence of ColR in this cohort as the primary factor driving ColR. Importantly, mortality was increased in patients with ColR isolates.
Full Text
Duke Authors
Cited Authors
- Rojas, LJ; Salim, M; Cober, E; Richter, SS; Perez, F; Salata, RA; Kalayjian, RC; Watkins, RR; Marshall, S; Rudin, SD; Domitrovic, TN; Hujer, AM; Hujer, KM; Doi, Y; Kaye, KS; Evans, S; Fowler, VG; Bonomo, RA; van Duin, D; Antibacterial Resistance Leadership Group,
Published Date
- March 15, 2017
Published In
- Clinical Infectious Diseases : an Official Publication of the Infectious Diseases Society of America
Volume / Issue
- 64 / 6
Start / End Page
- 711 - 718
PubMed ID
- 27940944
Pubmed Central ID
- 27940944
Electronic International Standard Serial Number (EISSN)
- 1537-6591
Digital Object Identifier (DOI)
- 10.1093/cid/ciw805
Language
- eng
Conference Location
- United States