Klebsiella pneumoniae carbapenemase (KPC)-producing bacteria are a group of emerging highly drug-resistant Gram-negative bacilli causing infections associated with significant morbidity and mortality. Once confined to outbreaks in the northeastern United States (US), they have spread throughout the US and most of the world. KPCs are an important mechanism of resistance for an increasingly wide range of Gram-negative bacteria and are no longer limited to K pneumoniae. KPC-producing bacteria are often misidentified by routine microbiological susceptibility testing and incorrectly reported as sensitive to carbapenems; however, resistance to the carbapenem antibiotic ertapenem is common and a better indicator of the presence of KPCs. Carbapenem antibiotics are generally not effective against KPC-producing organisms. The best therapeutic approach to KPC-producing organisms has yet to be defined; however, common treatments based on in vitro susceptibility testing are the polymyxins, tigecycline, and less frequently aminoglycoside antibiotics. The purpose of this review is to identify the various challenges that KPC-producing bacteria present to clinicians. These include the need for special techniques for microbiological detection, the potential for nosocomial transmission, and therapeutic challenges related to limited, relatively unproven antimicrobial treatment options.

Critical illness and underlying medical conditions, CRE colonization pressure, and antimicrobial exposure are important risk factors for CRE acquisition. Adherence to infection control practices and antimicrobial stewardship appear to be critical components of a CRE control program.

The majority of MDR TB patients on linezolid had favourable treatment outcomes, although treatment was complicated by adverse events that required extensive clinical management.

A recent, frequently quoted study has suggested that for bloodstream infections (BSIs) due to extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL) Escherichia coli, treatment with β-lactam/β-lactamase inhibitors (BLBLIs) might be equivalent to treatment with carbapenems. However, the majority of BSIs originate from the urinary tract. A multicenter, multinational efficacy analysis was conducted from 2010 to 2012 to compare outcomes of patients with non-urinary ESBL BSIs who received a carbapenem (69 patients) vs those treated with piperacillin-tazobactam (10 patients). In multivariate analysis, therapy with piperacillin-tazobactam was associated with increased 90-day mortality (adjusted odds ratio, 7.9, P=.03). For ESBL BSIs of a non-urinary origin, carbapenems should be considered a superior treatment to BLBLIs.