Molecular surveillance of carbapenemase-producing Pseudomonas aeruginosa at three medical centres in Cologne, Germany

Abstract

BackgroundPseudomonas aeruginosa is a common pathogen causing hospital-acquired infections. Carbapenem resistance in P. aeruginosa is either mediated via a combination of efflux pumps, AmpC overexpression, and porin loss, or through an acquired carbapenemase. Carbapenemase-producing P. aeruginosa (CPPA) strains are known to cause outbreaks and harbour a reservoir of mobile antibiotic resistance genes, however, few molecular surveillance data is available. The aim of this study was to analyse the prevalence and epidemiology of CPPA in three German medical centres from 2015 to 2017.MethodsIdentification and susceptibility testing were performed with VITEK 2 system. P. aeruginosa non-susceptible to piperacillin, ceftazidime, cefepime, imipenem, meropenem and ciprofloxacin (4MRGN according to the German classification guideline) isolated from 2015 to 2017 were analysed. A two-step algorithm to detect carbapenemases was performed: phenotypic tests (EDTA- and cloxacillin-combined disk tests) followed by PCR, Sanger sequencing, and eventually whole genome sequencing. CPPA isolates were further genotyped by RAPD and PFGE. In-hospital transmission was investigated using conventional epidemiology.ResultsSixty two P. aeruginosa isolates were available for further analysis, of which 21 were CPPA as follows: blaVIM-1 (n = 2), blaVIM-2 (n = 17), blaNDM-1/blaGES-5 (n = 1) and the newly described blaIMP-82 (n = 1). CPPA were mostly hospital-acquired (71.4%) and isolated on intensive care units (66.7%). All (except one) were from the tertiary care centre. PFGE typing revealed one large cluster of VIM-2-producing CPPA containing 13 isolates. However, using conventional epidemiology, we were only able to confirm three patient-to-patient transmissions, and one room-to-patient transmission, on several intensive care units.ConclusionsThese data give insight into the epidemiology of CPPA in three centres in Germany over a period of 3 years. Carbapenemases are a relevant resistance mechanism in 4MRGN-P. aeruginosa, illustrated by genetically related VIM-2-producing strains that seem to be endemic in this region. Our data suggest that infection control measures should especially focus on controlling transmission on the ICU and support the need for a local molecular surveillance system.

Performance of the BD Phoenix CPO detect assay for detection and classification of carbapenemase-producing organisms

“…In fact, a limitation of our study is the restriction of the reference method to detect only the most common carbapenemase-encoding genes, including class A (KPC, GES, NMC-A/IMI, BIC, SME), class B (VIM, NDM, IMP), and class D (Oxa-48, Oxa-23, Oxa-24) carbapenemases [17,31]. Although being the most prevalent and clinically relevant determinants of carbapenemase-mediated resistance in Germany [32][33][34][35], the presence of carbapenemases not covered by the PCR assay employed cannot be excluded. To compensate for the potential sensitivity limitation, all PCR-negative isolates were additionally tested using a phenotypic carbapenemase assay (i.e., CIM; [21]).…”

Global Threat of Carbapenem-Resistant Gram-Negative Bacteria

“…In stark contrast, the 2015–2017 CR- P. A study by Schäfer et al. at three medical centers in Germany revealed that 30.6% (19/62) of the samples harbored either bla VIM-1 (n = 2) or bla VIM-2 (n = 17) genes ( Schäfer et al., 2019 ). The bla VIM carriage rate among CR- P. aeruginosa isolates was similar to that in the 2007–2009 survey conducted in Uganda (32%) ( Kateete et al., 2016 ), and that in the 2015–2016 survey of Dubai hospitals in the United Arab Emirates (32%) ( Moubareck et al., 2019 ).…”

Prevalence of Imipenem-Resistant Acinetobacter baumannii isolates in Iran: A Meta-Analysis

“…baumannii is a multidrug-resistant nosocomial pathogen that causes severe infections among patients especially in ICU and can hydrolyze various β-lactam antibiotics by different enzymes such as carbapenemases [131,132] . Among bacteria, resistance to carbapenems, especially imipenem, has been reported from various countries as well as in Iran [133][134][135] . Recently due to resistance of A. baumannii to a wide range of antimicrobial agents, raise a concern on controlling lifethreatening infections worldwide [136] .…”