Introduction: Infections caused by Klebsiella pneumoniae (Kp), specifically Kp producing Klebsiella pneumoniae carbapenemases (Kp-KPC), are an emerging problem worldwide with an increased incidence of infections by these microorganisms in recent years. Recipients of a solid organ transplant constitute a population at high risk to suffer infections by this type of germs. Our objective was to describe the clinical and microbiological characteristics of the infections caused by K. pneumoniae-KPC in kidney transplant patients (KT) in the context of an outbreak detected in our hospital in July 2012.
Materials and Methods: Clinical and microbiological data were collected from KT recipients, in which K. pneumoniae-KPC was isolated in any location, carrying out the identification and genetic characterization of the responsible clone by the use of pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). After data collection was completed, patients were followed up to the present time.
Results: Thirteen patients with Kp-KPC infection were collected: 9 men and 4 women with a median age of 70 years (range 27-78). 11 were recipients of a KT, 1 of simultaneous pancreas-kidney and 1 of simultaneous liver-kidney transplant. 46% had previous intestinal colonization. 62% had received antibiotic treatment in the previous month. The most frequent source of infection was the urinary tract (8/15), followed by respiratory (3/15), abdominal (2/15), venous catheter (1/15) and primary bacteremia (1/15). Blood cultures were positive in 39% of these subjects. Infection was more frequent along the first year after transplantation, with an increase in incidence from the second month post-transplant. Combined treatment was performed in 92% of the cases: fosfomycin + tigecycline (5/13), fosfomycin + gentamicin (3/13), tigecycline + gentamicin (2/13) and tigecycline + fosfomycin + gentamicin (2/13); only 1 patient was treated using monotherapy with fosfomycin. In one case, rescue therapy with ceftazidime/avibactam was used. Cure was achieved in 62% of patients. Crude mortality at 30 days was 23% and that related to Kp-KPC infection was of 15%. The ST512 clone, producer of the carbapenemic resistance enzyme KPC-3, has been identified as the one responsible for the outbreak originated in our hospital.
Conclusions: In our series, episodes of Kp-KPC infection in kidney transplant patients have been more frequent since the 2nd month post-transplant, with the urinary tract being the most frequent focus and requiring combined treatment in most cases, achieving clinical cure and microbiological eradication in most patients.