Outbreak News Today
Infections with bacteria resistant to carbapenems, a group of highly effective antibiotics, pose a significant threat to patients and healthcare systems in all EU/EEA countries, warns ECDC in a Rapid Risk Assessment.
Resistance to carbapenems has been reported with increasing frequency and geographical spread since the beginning of the 1990s. The global rise of carbapenem resistance in a certain family of bacteria called Enterobacteriaceae, or carbapenem-resistant Enterobactericaeae (CRE), represents a threat to healthcare delivery and patient safety.
“We should be very concerned about the rise in carbapenem resistance in the EU/EEA as there are very few options for the treatment of patients with CRE infections” says Dominique Monnet, Head of ECDC’s Antimicrobial Resistance and Healthcare-Associated Infections Programme. “In recent years, the proportions of carbapenem resistance in Klebsiella pneumoniae – a type of Enterobacteriaceae – rapidly increased to high levels in Greece, Italy and Romania. The same could happen to other EU/EEA countries if appropriate measures are not taken. But the spread of CRE can likely be controlled in most countries through the implementation of appropriate prevention and control measures in hospitals and other healthcare settings.”
Two teams of scientists at the annual meeting of the American Society for Microbiology (ASM) are reporting worrisome findings involving multidrug-resistant bacteria in healthcare settings.
In one study, a team led by researchers from Emory Antibiotic Resistance Center reported the first isolation of hypervirulent, multidrug-resistant Klebsiella pneumoniae in the United States. In another, researchers with the Kentucky Department for Public Health and the Centers for Disease Control and Prevention (CDC) found that a small outbreak of carbapenem-resistant infections at a Kentucky hospital in 2017 were caused by different strains and species of bacteria that carried the same drug-resistance plasmids.
Both studies highlight concerns about carbapenem-resistant Enterobacteria (CRE), which cause more than 9,000 healthcare-associated infections each year and have been dubbed “nightmare” bacteria for their resistance to several classes of antibiotics and their ability to spread quickly in healthcare settings. CRE infections, including bloodstream, wound, and urinary tract infections, are exceedingly difficult to treat and have a mortality rate of nearly 50%.
Polymyxins remain the last line treatment for multidrug-resistant (MDR) infections. As polymyxins resistance emerges, there is an urgent need to develop effective antimicrobial agents capable of mitigating MDR. Here, we report biodegradable guanidinium-functionalized polycarbonates with a distinctive mechanism that does not induce drug resistance. Unlike conventional antibiotics, repeated use of the polymers does not lead to drug resistance. Transcriptomic analysis of bacteria further supports development of resistance to antibiotics but not to the macromolecules after 30 treatments. Importantly, high in vivo treatment efficacy of the macromolecules is achieved in MDR A. baumannii-, E. coli-, K. pneumoniae-, methicillin-resistant S. aureus-, cecal ligation and puncture-induced polymicrobial peritonitis, and P. aeruginosa lung infection mouse models while remaining non-toxic (e.g., therapeutic index—ED50/LD50: 1473 for A. baumannii infection). These biodegradable synthetic macromolecules have been demonstrated to have broad spectrum in vivo antimicrobial activity, and have excellent potential as systemic antimicrobials against MDR infections.
To compare the epidemiology, clinical characteristics, and mortality of patients with bloodstream infections (BSI) caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) versus ESBL-producing Klebsiella pneumoniae (ESBL-KP) and to examine the differences in clinical characteristics and outcome between BSIs caused by isolates with CTX-M versus other ESBL genotypes
As part of the INCREMENT project, 33 tertiary hospitals in 12 countries retrospectively collected data on adult patients diagnosed with ESBL-EC BSI or ESBL-KP BSI between 2004 and 2013. Risk factors for ESBL-EC versus ESBL-KP BSI and for 30-day mortality were examined by bivariate analysis followed by multivariable logistic regression.
The study included 909 patients: 687 with ESBL-EC BSI and 222 with ESBL-KP BSI. ESBL genotype by polymerase chain reaction amplification of 286 isolates was available. ESBL-KP BSI was associated with intensive care unit admission, cardiovascular and neurological comorbidities, length of stay to bacteremia >14 days from admission, and a nonurinary source. Overall, 30-day mortality was significantly higher in patients with ESBL-KP BSI than ESBL-EC BSI (33.7% vs 17.4%; odds ratio, 1.64; P=.016). CTX-M was the most prevalent ESBL subtype identified (218 of 286 polymerase chain reaction-tested isolates, 76%). No differences in clinical characteristics or in mortality between CTX-M and non–CTX-M ESBLs were detected.
Clinical characteristics and risk of mortality differ significantly between ESBL-EC and ESBL-KP BSI. Therefore, all ESBL-producing Enterobacteriaceae should not be considered a homogeneous group. No differences in outcomes between genotypes were detected.
CLINICAL TRIALS IDENTIFIER
ClinicalTrials.gov. Identifier: NCT01764490.
Infect Control Hosp Epidemiol 2018;1–8