Carbapenem-Resistant Pseudomonas aeruginosa at US Emerging Infections Program Sites, 2015.

Maroya Spalding Walters,Julian E Grass,Emily B Hancock,Jackie Mounsey,Margret Oethinger,Karissa Culbreath,J Kamile Rasheed,Uzma Ansari,Cathleen Concannon,Chris Bower,Walter E Phillips,Roberto L Vargas,Daniel Muleta,Marion A Kainer,P Maureen Cassidy,Dwight J Hardy,Maria Karlsson,Alison Laufer Halpin,Ghinwa Dumyati,Richard A Stanton ,Sandra N Bulens ,Erin C Phipps ,Zintars G Beldavs ,Valérie Albrecht ,Jesse T Jacob ,Alexander J Kallen

doi:10.3201/eid2507.181200

Abstract

Pseudomonas aeruginosa is intrinsically resistant to many antimicrobial drugs, making carbapenems crucial in clinical management. During July–October 2015 in the United States, we piloted laboratory-based surveillance for carbapenem-resistant P. aeruginosa (CRPA) at sentinel facilities in Georgia, New Mexico, Oregon, and Tennessee, and population-based surveillance in Monroe County, NY. An incident case was the first P. aeruginosa isolate resistant to antipseudomonal carbapenems from a patient in a 30-day period from any source except the nares, rectum or perirectal area, or feces. We found 294 incident cases among 274 patients. Cases were most commonly identified from respiratory sites (120/294; 40.8%) and urine (111/294; 37.8%); most (223/280; 79.6%) occurred in patients with healthcare facility inpatient stays in the prior year. Genes encoding carbapenemases were identified in 3 (2.3%) of 129 isolates tested. The burden of CRPA was high at facilities under surveillance, but carbapenemase-producing CRPA were rare.

Highlights

Infections caused by P. aeruginosa are associated with substantial morbidity and mortality rates; a recent study of bloodstream infections showed that patients with a Pseudomonas bloodstream infection had a higher mortality rate than patients with infections caused by members of Enterobacteriaceae or other non–lactose fermenting gram-negative bacilli [3]
9% of P. aeruginosa isolates from these sites were carbapenem-resistant, only 2% of carbapenemresistant P. aeruginosa (CRPA) isolates tested had an identified carbapenemase, suggesting that these resistance mechanisms are rare in P. aeruginosa at the surveillance sites
Nearly half of cases were from specimens collected outside of acute-care settings, 92% of patients had healthcare exposures before their positive culture, and 98% had >1 underlying condition, indicating that CRPA remains primarily a healthcare-associated pathogen affecting persons with serious medical issues

Summary

Introduction

Infections with P. aeruginosa are often challenging to treat because of its intrinsic nonsusceptibility to many commonly used antimicrobial drugs; ≈13% of isolates causing HAI are multidrug resistant (MDR) [2]. For these reasons, carbapenems have become important antimicrobial drugs for clinical management of serious P. aeruginosa infections. Carbapenem resistance among Pseudomonas spp. is a concern; in 2014, 19.1% of P. aeruginosa associated with selected HAI and reported to the NHSN were not susceptible to carbapenems [4] This proportion has remained stable since 2009 [1,5], some reports have suggested recent increases in the prevalence of carbapenemresistant P. aeruginosa (CRPA) among certain subpopulations, including children [6]. A study of isolates from 14 countries in Europe showed that the prevalence of metallo-β-lactamase (MBL)–producing P. aeruginosa increased from 12.3% in 2010 to 30.6% in 2011 [7]

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Conclusion