Summary Klebsiella pneumoniae carbapenemases (KPCs) were originally identified in the USA in 1996. Since then, these versatile β-lactamases have spread internationally among Gram-negative bacteria, ...especially K pneumoniae , although their precise epidemiology is diverse across countries and regions. The mortality described among patients infected with organisms positive for KPC is high, perhaps as a result of the limited antibiotic options remaining (often colistin, tigecycline, or aminoglycosides). Triple drug combinations using colistin, tigecycline, and imipenem have recently been associated with improved survival among patients with bacteraemia. In this Review, we summarise the epidemiology of KPCs across continents, and discuss issues around detection, present antibiotic options and those in development, treatment outcome and mortality, and infection control. In view of the limitations of present treatments and the paucity of new drugs in the pipeline, infection control must be our primary defence for now.
Abstract Background Although Klebsiella pneumoniae is the second most common cause of Gram-negative bloodstream infections, its epidemiology has not been defined in a nonselected population. We ...sought to describe the incidence of, risk factors for, and outcomes associated with K. pneumoniae bacteremia. Methods Population-based surveillance for K. pneumoniae bacteremia was conducted in the Calgary Health Region (population 1.2 million) from 2000 to 2007. Results A total of 640 episodes of K. pneumoniae bacteremia were identified for an overall annual population incidence of 7.1 per 100,000; 174 (27%) were nosocomial, 276 (43%) were healthcare-associated community onset, and 190 (30%) were community acquired. Elderly patients and men were at highest risk for K. pneumoniae bacteremia. Dialysis, solid-organ transplantation, chronic liver disease, and cancer were the most important risk factors for acquiring K. pneumoniae bacteremia. Rates of resistance to trimethoprim/sulfamethoxazole increased significantly during 2000 to 2007. The case fatality rate was 20%, and the annual population mortality rate was 1.3 per 100,000. Increasing age, nosocomial acquisition, non-urinary and non-biliary focus of infection, and several comorbid illnesses were independently associated with an increased risk of death. Conclusion This is the first population-based study to document the major burden of illness associated with K. pneumoniae bacteremia and identifies groups at increased risk of acquiring and dying of these infections.
Summary The medical community relies on clinical expertise and published guidelines to assist physicians with choices in empirical therapy for system-based infectious syndromes, such as ...community-acquired pneumonia and urinary-tract infections (UTIs). From the late 1990s, multidrug-resistant Enterobacteriaceae (mostly Escherichia coli ) that produce extended-spectrum β lactamases (ESBLs), such as the CTX-M enzymes, have emerged within the community setting as an important cause of UTIs. Recent reports have also described ESBL-producing E coli as a cause of bloodstream infections associated with these community-onset UTIs. The carbapenems are widely regarded as the drugs of choice for the treatment of severe infections caused by ESBL-producing Enterobacteriaceae, although comparative clinical trials are scarce. Thus, more rapid diagnostic testing of ESBL-producing bacteria and the possible modification of guidelines for community-onset bacteraemia associated with UTIs are required.
Background. A study was conducted in the Calgary Health Region between May 2002 and April 2004 to define the population‐based epidemiological characteristics of infections caused by ...imipenem‐resistant Pseudomonas aeruginosa and to explore the clinical outcomes due to metallo‐β‐lactamase (MBL)–producing and non–MBL‐producing strains. Methods. Detailed clinical information was obtained by chart review, and phenotypic and molecular characterizations were performed using the MBL E‐test, polymerase chain reaction with sequencing, and pulsed‐field gel electrophoresis. Results. A total of 228 patients with infections caused by imipenem‐resistant P. aeruginosa were identified (annual incidence, 10.5 cases/100,000 population), with the highest incidence rate in those ⩾75 years old. MBL‐producing strains (98/228) were associated with higher rates of multidrug resistance and bacteremia. Ninety MBL‐producing strains also produced VIM‐2, 4 produced IMP‐7, and 4 were unclassified. A cluster of VIM‐2–producing strains was responsible for a nosocomial outbreak during 2003. The case‐fatality rate was significantly higher for infections caused by MBL‐producing strains than for those caused by non–MBL‐producing strains (25% vs. 13%; relative risk, 1.98 95% confidence interval, 1.00–3.90; P=.05). Conclusion. MBL‐producing P. aeruginosa strains were associated with a higher case‐fatality rate and invasive disease. Our study highlights the potential importance of molecular laboratory techniques in infection control and patient care.
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