Nationwide, population-based observational study of the molecular epidemiology and temporal trend of carbapenemase-producing Enterobacterales in Norway, 2015 to 2021

National and regional carbapenemaseproducing Enterobacterales (CPE) surveillance is essential to understand the burden of antimicrobial resistance, elucidate outbreaks, and develop infection-control or antimicrobial-treatment recommendations. Aim: This study aimed to describe CPE and their epidemiology in Norway from 2015 to 2021. Methods: A nationwide, population-based observational study of all verified clinical and carriage CPE isolates submitted to the national reference laboratory was conducted. Isolates were characterised by antimicrobial susceptibility testing, whole genome sequencing (WGS) and basic metadata. Annual CPE incidences were also estimated. Results: A total of 389 CPE isolates were identified from 332 patients of 63years median age (range:0–98). These corresponded to 341 cases, 184 (54%) being male. Between 2015 and 2021, the annual incidence of CPE cases increased from 0.6 to 1.1per 100,000person-years. For CPEisolates with available data on colonisation/infection, 58% (226/389)were associated with colonisation and 38% (149/389) with clinical infections. WGS revealed a predominance of OXA-48-like (51%; 198/389) and NDM (34%; 134/389) carbapenemases in a diversified population of Escherichia coli and Klebsiella pneumoniae, including high-risk clones also detected globally. Most CPE isolates were travel-related (63%;245/389). Although local outbreaks and healthcare-associated transmission occurred, no interregional spread was detected. Nevertheless, 18% (70/389) of isolates not directly related to import points towards potentially unidentified transmission routes. A decline in travelassociated cases was observed during the COVID-19 pandemic. Conclusions: The close-to-doubling of CPE case incidence between 2015 and 2021 was associated with foreign travel and genomic diversity. To limit further transmission and outbreaks, continued screening and monitoring is essential

Emergence and dissemination of antimicrobial resistance in Escherichia coli causing bloodstream infections in Norway in 2002-17: a nationwide, longitudinal, microbial population genomic study.

BACKGROUND: The clonal diversity underpinning trends in multidrug resistant Escherichia coli causing bloodstream infections remains uncertain. We aimed to determine the contribution of individual clones to resistance over time, using large-scale genomics-based molecular epidemiology. METHODS: This was a longitudinal, E coli population, genomic, cohort study that sampled isolates from 22 512 E coli bloodstream infections included in the Norwegian surveillance programme on resistant microbes (NORM) from 2002 to 2017. 15 of 22 laboratories were able to share their isolates, and the first 22·5% of isolates from each year were requested. We used whole genome sequencing to infer the population structure (PopPUNK), and we investigated the clade composition of the dominant multidrug resistant clonal complex (CC)131 using genetic markers previously reported for sequence type (ST)131, effective population size (BEAST), and presence of determinants of antimicrobial resistance (ARIBA, PointFinder, and ResFinder databases) over time. We compared these features between the 2002-10 and 2011-17 time periods. We also compared our results with those of a longitudinal study from the UK done between 2001 and 2011. FINDINGS: Of the 3500 isolates requested from the participating laboratories, 3397 (97·1%) were received, of which 3254 (95·8%) were successfully sequenced and included in the analysis. A significant increase in the number of multidrug resistant CC131 isolates from 71 (5·6%) of 1277 in 2002-10 to 207 (10·5%) of 1977 in 2011-17 (p<0·0001), was the largest clonal expansion. CC131 was the most common clone in extended-spectrum β-lactamase (ESBL)-positive isolates (75 [58·6%] of 128) and fluoroquinolone non-susceptible isolates (148 [39·2%] of 378). Within CC131, clade A increased in prevalence from 2002, whereas the global multidrug resistant clade C2 was not observed until 2007. Multiple de-novo acquisitions of both blaCTX-M ESBL-encoding genes in clades A and C1 and gain of phenotypic fluoroquinolone non-susceptibility across the clade A phylogeny were observed. We estimated that exponential increases in the effective population sizes of clades A, C1, and C2 occurred in the mid-2000s, and in clade B a decade earlier. The rate of increase in the estimated effective population size of clade A (Ne=3147) was nearly ten-times that of C2 (Ne=345), with clade A over-represented in Norwegian CC131 isolates (75 [27·0%] of 278) compared with the UK study (8 [5·4%] of 147 isolates). INTERPRETATION: The early and sustained establishment of predominantly antimicrobial susceptible CC131 clade A isolates, relative to multidrug resistant clade C2 isolates, suggests that resistance is not necessary for clonal success. However, even in the low antibiotic use setting of Norway, resistance to important antimicrobial classes has rapidly been selected for in CC131 clade A isolates. This study shows the importance of genomic surveillance in uncovering the complex ecology underlying multidrug resistance dissemination and competition, which have implications for the design of strategies and interventions to control the spread of high-risk multidrug resistant clones. FUNDING: Trond Mohn Foundation, European Research Council, Marie Skłodowska-Curie Actions, and the Wellcome Trust

Extended-spectrum β-lactamases and carbapenemases in clinical isolates of Enterobacteriaceae in Norway. Aspects of detection and epidemiology.

Paper 1, 2 and 3 of this thesis are not available in Munin: 1. Tofteland S, Haldorsen B, Dahl KH, Simonsen GS, Steinbakk M, Walsh TR, Sundsfjord A; Norwegian ESBL Study Group.: ‘Effects of phenotype and genotype on methods for detection of extended-spectrum-beta-lactamase-producing clinical isolates of Escherichia coli and Klebsiella pneumoniae in Norway’. J.Clin.Microbiol. 2007; 45(1):199-205. Avalable in J.Clin.Microbiol. 2007; 45(1):199-205 2. Naseer U, Haldorsen B, Tofteland S, Hegstad K, Scheutz F, Simonsen GS, Sundsfjord A;Norwegian ESBL Study Group.: ‘Molecular characterization of CTX-M-15-producing clinical isolates of Escherichia coli reveals the spread of multidrug-resistant ST131 (O25:H4) and ST964 (O102:H6) strains in Norway’. APMIS. 2009;117(7):526-36. Available in APMIS. 2009;117(7):526-36 3. Tofteland S, Dahl KH, Aasnæs B, Sundsfjord A, Naseer U.: ' A nationwide study of mechanisms conferring reduced susceptibility to extended-spectrum cephalosporins in clinical Escherichia coli and Klebsiella spp. isolates'. Scand J Infect Dis. 2012;44(12):927-33. Available in Scand J Infect Dis. 2012;44 (12), 927-33</a

A Long-Term Low-Frequency Hospital Outbreak of KPC-Producing Klebsiella pneumoniae Involving Intergenus Plasmid Diffusion and a Persisting Environmental Reservoir

Background: To study the molecular characteristics of a long-term, low frequency outbreak of blaKPC-2 in a low prevalence setting involving the hospital environment. Methodology/Principal Findings: KPC-producing bacteria were screened by selective chromogenic agar and Real-Time PCR. The presence of antibiotic resistance genes was ascribed by PCRs and subsequent sequencing, and the KPC-producing isolates were phylogenetically typed using PFGE and multi-locus sequence typing. BlaKPC-2-plasmids were identified and analysed by S1-nuclease-PFGE hybridization and PCR based replicon typing. A ,97 kb IncFII plasmid was seen to carry blaKPC-2 in all of the clinical isolates, in one of the isolates recovered from screened patients (1/136), and in the Klebsiella pneumoniae and Enterobacter asburiae isolates recovered from the environment (sinks) in one intensive care unit. The K. pneumoniae strain ST258 was identified in 6 out of 7 patients. An intergenus spread to E. asburiae and an interspecies spread to two different K. pneumoniae clones (ST27 and ST461) of the blaKPC-2 plasmid was discovered. K. pneumoniae ST258 and genetically related E. asburiae strains were found in isolates of both human and environmental origins. Conclusions/Significance: We document a clonal transmission of the K. pneumoniae ST258 strain, and an intergenus plasmid diffusion of the IncFII plasmid carrying blaKPC-2 in this outbreak. A major reservoir in the patient population could not be unveiled. However, the identification of a persisting environmental reservoir of strains with molecular determinants linked to human isolates, suggests a possible role of the environment in the maintenance of this long-term outbreak

Effects of Phenotype and Genotype on Methods for Detection of Extended-Spectrum-β-Lactamase-Producing Clinical Isolates of Escherichia coli and Klebsiella pneumoniae in Norway

Consecutive clinical isolates of Escherichia coli (n = 87) and Klebsiella pneumoniae (n = 25) with reduced susceptibilities to oxyimino-cephalosporins (MICs > 1 mg/liter) from 18 Norwegian laboratories during March through October 2003 were examined for bla(TEM/SHV/CTX-M) extended-spectrum-β-lactamase (ESBL) genes, oxyimino-cephalosporin MIC profiles, ESBL phenotypes (determined by the ESBL Etest and the combined disk and double-disk synergy [DDS] methods), and susceptibility to non-β-lactam antibiotics. Multidrug-resistant CTX-M-15-like (n = 23) and CTX-M-9-like (n = 15) ESBLs dominated among the 50 ESBL-positive E. coli isolates. SHV-5-like (n = 9) and SHV-2-like (n = 4) ESBLs were the most prevalent in 19 ESBL-positive K. pneumoniae isolates. Discrepant ESBL phenotype test results were observed for one major (CTX-M-9) and several minor (TEM-128 and SHV-2/-28) ESBL groups and in SHV-1/-11-hyperproducing isolates. Negative or borderline ESBL results were observed when low-MIC oxyimino-cephalosporin substrates were used to detect clavulanic acid (CLA) synergy. CLA synergy was detected by the ESBL Etest and the DDS method but not by the combined disk method in SHV-1/-11-hyperproducing strains. The DDS method revealed unexplained CLA synergy in combination with aztreonam and cefpirome in three E. coli strains. The relatively high proportion of ESBL-producing E. coli organisms with a low ceftazidime MIC in Norway emphasizes that cefpodoxime alone or both cefotaxime and ceftazidime should be used as substrates for ESBL detection

Clinical data and risk factors for outbreak patients.

1)<p>Except urinary catheter.</p>2)<p>I =  admission to ICU, S =  recent surgery (laparotomi), R =  artificial ventilator use, D =  subjected to haemodialysis.</p>3)<p>Patient 1, being readmitted to SH-K, and patient 2 had been hospitalized in the same corridor for two days in March 2008 at SH-K although at separately staffed wards (Med. 2A-K and Med. 2C-K). Measures for contact isolation were not implemented for patient 1 on this occasion.</p>4)<p>Patient 4 and patient 5 had been admitted simultaneously to the ICU-A, and had also been referred to a tertiary hospital (OUS-RH) at overlapping intervals.</p>5)<p>Patient 3 and patient 4 were hospitalized in the ICU-A two days apart.</p>6)<p>LOS = length of stay (days).</p>7)<p>Overlap between patients in time and wards.</p>8)<p>Anti G-negative antibiotics prior to diagnosis</p

Dendrogram of XbaI-digested genomic DNA.

<p>Strains of KPC-producing <i>K. pneumoniae-</i> and <i>E.asburiae</i>-isolates and ESBL_A-producing <i>K. pneumonia</i> are shown with percentages of similarity to the right of the dendrogram.</p

Molecular characteristics of outbreak strains.

1)<p>P1–6 =  clinical specimen from patients 1–6, P7/F =  fecal screen patient 7, E = specimen from environmental screen (rooms 5, 6).</p>2)<p><i>bla</i>_CTX-M was negative in all isolates. <i>bla</i>_pAmpC was negative in isolates from patients 1–6, others ND.</p>3)<p>Plasmid profiling (S1-nuclease digested DNA (kB)).</p>4)<p>Plasmid DNA hybridization with <i>bla</i>_KPC specific probes.</p

PFGE of S1 nuclease-digested total DNA.

<p>Lanes 1 and 20, phage λ DNA ladder (concatemers of 48.5 kb); lane 2, K47-25; lane 3, K48-58; lane 4, K52-74; lane 5, K54-05; lane 6, K57-33; lane 7, K66-62; lane 8, K66-73; lane 9, K66-74; lane 10, K67-04; lane 11, K67-05; lane 12, K67-06; lane 13, K67-11; lane 14, K67-12; lane 15, K67-13; lane 16, K67-14; lane 17, K67-15; lane 18, K67-16; lane 19, <i>K. pneumoniae bla</i>_KPC -negative control strain.</p

An estimate of the burden of fungal disease in Norway

The aim of this study was to examine the burden of fungal disease in Norway, contributing to a worldwide effort to improve awareness of the needs for better diagnosis and treatment of such infections. We used national registers and actual data from the Departments of Microbiology from 2015 and estimated the incidence and/or prevalence of superficial, allergic and invasive fungal disease using published reports on specific populations at risk. One in 6 Norwegians suffered from fungal disease: Superficial skin infections (14.3%: 745,600) and recurrent vulvovaginal candidiasis in fertile women (6%: 43,123) were estimated to be the most frequent infections. Allergic fungal lung disease was estimated in 17,755 patients (341/100,000). Pneumocystis jirovecii was diagnosed in 262 patients (5/100,000), invasive candidiasis in 400 patients (7.7/100,000), invasive aspergillosis in 278 patients (5.3/100,000) and mucormycosis in 7 patients (0.1/100,000). Particular fungal infections from certain geographic areas were not observed. Overall, 1.79% of the population was estimated to be affected by serious fungal infections in Norway in 2015. Even though estimates for invasive infections are small, the gravity of such infections combined with expected demographic changes in the future emphasizes the need for better epidemiological data. View Full-Tex