Impact of the ST101 clone on fatality among patients with colistin-resistant Klebsiella pneumoniae infection

• Published in: Journal of antimicrobial chemotherapy 2018-05, Vol.73 (5), p.1235-1241
• Main Authors: Can, Fusun, Menekse, Sirin, Ispir, Pelin, Atac, Nazli, Albayrak, Ozgur, Demir, Tuana, Karaaslan, Doruk Can, Karahan, Salih Nafiz, Kapmaz, Mahir, Kurt Azap, Ozlem, Timurkaynak, Funda, Simsek Yavuz, Serap, Basaran, Seniha, Yoruk, Fugen, Azap, Alpay, Koculu, Safiye, Benzonana, Nur, Lack, Nathan A, Gönen, Mehmet, Ergonul, Onder
• Format: Article
• Language: English
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dkx532

We describe the molecular characteristics of colistin resistance and its impact on patient mortality. A prospective cohort study was performed in seven different Turkish hospitals. The genotype of each isolate was determined by MLST and repetitive extragenic palindromic PCR (rep-PCR). Alterations in mgrB were detected by sequencing. Upregulation of pmrCAB, phoQ and pmrK was quantified by RT-PCR. mcr-1 and the genes encoding OXA-48, NDM-1 and KPC were amplified by PCR. A total of 115 patients diagnosed with colistin-resistant K. pneumoniae (ColR-Kp) infection were included. Patients were predominantly males (55%) with a median age of 63 (IQR 46-74) and the 30 day mortality rate was 61%. ST101 was the most common ST and accounted for 68 (59%) of the ColR-Kp. The 30 day mortality rate in patients with these isolates was 72%. In ST101, 94% (64/68) of the isolates had an altered mgrB gene, whereas the alteration occurred in 40% (19/47) of non-ST101 isolates. The OXA-48 and NDM-1 carbapenemases were found in 93 (81%) and 22 (19%) of the total 115 isolates, respectively. In multivariate analysis for the prediction of 30 day mortality, ST101 (OR 3.4, CI 1.46-8.15, P = 0.005) and ICU stay (OR 7.4, CI 2.23-29.61, P = 0.002) were found to be significantly associated covariates. Besides ICU stay, ST101 was found to be a significant independent predictor of patient mortality among those infected with ColR-Kp. A significant association was detected between ST101 and OXA-48. ST101 may become a global threat in the dissemination of colistin resistance and the increased morbidity and mortality of K. pneumoniae infection.