Dissemination of colistin-resistant and colistin-susceptible KPC-producing Klebsiella pneumoniae in the course of two consecutive outbreaks in a Brazilian intensive care unit

Abstract Background Carbapenem-resistant Enterobacteriaceae (CRE), especially those that produce Klebsiella pneumoniae carbapenemase (KPC) and have associated with colistin resistance, poses a severe health threat due to the limited treatment options. Aims We describe two outbreaks of KPC-producing K. pneumoniae in an adult intensive care unit (AICU) in Brazil. In May 2015 14 patients had colistin-susceptible KPC-producing strains (ColS-KPC), and in July 2015 9 patients had colistin-resistant KPC-producing strains (ColR-KPC). Methods Between September 2014 and August 2015, we performed surveillance at a university hospital and all CRE were tested for blaKPC genes. Clonality was investigated by pulsed-field gel eletrophoresis. Resistance to colistin was confirmed by broth microdilution method. Consumption of carbapenems and colistin was expressed as defined daily doses. Findings 111 patients with CRE were identified during the surveillance period; K. pneumoniae was the major isolate (77.13%). The two outbreaks were identified when infection rates KPC/1000 patient-days exceeded the background level. Rates of carbapenem and colistin consumption were high. Control measures (bedside alcohol gel, contact precautions, regular rectal swabs) did not curtail the outbreaks. Mortality rates were 42.9% and 44.4% for ColS-KPC and ColR-KPC infected patients, respectively. After the death of four infected patients with ColR-KPC, the unit was closed to new admissions. Conclusions Our experience demonstrates the serious risks presented by KPD, and especially ColR-KPC, in Brazilian AICUs. Selective pressure from antibiotic overuse and transmission on healthcare staff’s workers’ hands were likely the major factors in transmission.