Import of global high-risk clones is the primary driver of carbapenemase-producing in Norway.

Infections by carbapenemase-producing (CP-Pa) are concerning due to limited treatment options. The emergence of multidrug-resistant (MDR) high-risk clones is an essential driver in the global rise of CP-Pa. Insights into the molecular epidemiology of CP-Pa are crucial to understanding its clinical and public health impact.

Diversity, functional classification and genotyping of SHV β-lactamases in .

Interpreting the phenotypes of alleles in genomes is complex. Whilst all strains are expected to carry a chromosomal copy conferring resistance to ampicillin, they may also carry mutations in chromosomal alleles or additional plasmid-borne alleles that have extended-spectrum β-lactamase (ESBL) activity and/or β-lactamase inhibitor (BLI) resistance activity. In addition, the role of individual mutations/a changes is not completely documented or understood.

Risk of death in Klebsiella pneumoniae bloodstream infections is associated with specific phylogenetic lineages.

Background: Klebsiella pneumoniae species complex (KpSC) bloodstream infections (BSIs) are associated with considerable morbidity and mortality, particularly in elderly and multimorbid patients. Multidrug-resistant (MDR) strains have been associated with poorer outcome. However, the clinical impact of KpSC phylogenetic lineages on BSI outcome is unclear.

FilmArray (BCID2) provides essential and timely results in bloodstream infections in small acute care hospitals without conventional microbiology services.

We have evaluated the performance of FilmArray BCID2 in reactive blood cultures in a small acute care hospital compared to conventional diagnostics at a regional microbiological laboratory. This is a retrospective observational study of BactAlert reactive blood cultures (n = 160) from Helgeland Hospital, July-December 2021, analysed by BCID2 locally and conventional culture at a regional laboratory. The overall clinical and analytic sensitivity with BCID2 were 87.

Pseudomonasaeruginosa antimicrobial susceptibility profiles, resistance mechanisms and international clonal lineages: update from ESGARS-ESCMID/ISARPAE Group.

Scope: Pseudomonas aeruginosa, a ubiquitous opportunistic pathogen considered one of the paradigms of antimicrobial resistance, is among the main causes of hospital-acquired and chronic infections associated with significant morbidity and mortality. This growing threat results from the extraordinary capacity of P. aeruginosa to develop antimicrobial resistance through chromosomal mutations, the increasing prevalence of transferable resistance determinants (such as the carbapenemases and the extended-spectrum β-lactamases), and the global expansion of epidemic lineages.

The first vanE-type vancomycin resistant Enterococcus faecalis isolates in Norway - phenotypic and molecular characteristics.

Objectives: We aimed to characterize the vanE cluster and its genetic support in the first Norwegian vanE-type isolates and assess genetic relatedness to other vanE isolates.

Methods: Two vanE-type vancomycin resistant Enterococcus faecalis (vanE-VREfs) isolates (E1 and E2) recovered from the same patient 30 months apart were examined for antimicrobial susceptibility, genome sequence, vancomycin resistance induction, vanE transferability, genome mutation rate, and phylogenetic relationship to E. faecalis closed genomes and two vanE-VREfs from North America.

The first tigecycline resistant Enterococcus faecium in Norway was related to tigecycline exposure.

Objectives: We describe the first tigecycline resistant enterococcal isolate in Norway and the mechanisms involved.

Material And Methods: The Norwegian National Advisory Unit on Detection of Antimicrobial Resistance (K-res). received in 2022 an Enterococcus faecium blood culture isolate with decreased susceptibility to tigecycline from a hospitalized patient in the South-Eastern Norway Health region for confirmatory testing.

The population structure of vancomycin-resistant and -susceptible in a low-prevalence antimicrobial resistance setting is highly influenced by circulating global hospital-associated clones.

Between 2010 and 2015 the incidence of vancomycin-resistant (VRE) in Norway increased dramatically. Hence, we selected (1) a random subset of vancomycin-resistant enterococci (VRE) from the Norwegian Surveillance System for Communicable Diseases (2010-15; =239) and (2) Norwegian vancomycin-susceptible (VSE) bacteraemia isolates from the national surveillance system for antimicrobial resistance in microbes (2008 and 2014; =261) for further analysis. Whole-genome sequences were collected for population structure, gene cluster, mobile genetic element and virulome analysis, as well as antimicrobial susceptibility testing.

Adaptive cell wall thickening in Enterococcus faecalis is associated with decreased vancomycin susceptibility.

Objectives: Enterococcus faecalis can adopt both a commensal and a nosocomial lifestyle, resisting numerous antibiotics. In this study, we aim to investigate the relationship between the cell wall (CW) thickness and decreased susceptibility to vancomycin (VD) in van-gene negative clinical isolates of E. faecalis (n = 2, n = 3, ST30, ST40, and ST59).

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

IntroductionNational and regional carbapenemase-producing Enterobacterales (CPE) surveillance is essential to understand the burden of antimicrobial resistance, elucidate outbreaks, and develop infection-control or antimicrobial-treatment recommendations.AimThis study aimed to describe CPE and their epidemiology in Norway from 2015 to 2021.MethodsA nationwide, population-based observational study of all verified clinical and carriage CPE isolates submitted to the national reference laboratory was conducted.

Intraregional hospital outbreak of OXA-244-producing ST38 in Norway, 2020.

Infections with OXA-244-carbapenemase-producing with sequence type (ST)38 have recently increased in Europe. Due to its low-level activity against carbapenems, OXA-244 can be difficult to detect. Previous assessments have not revealed a clear source and route of transmission for OXA-244-producing , but there are indications of non-healthcare related sources and community spread.

Community carriage of ESBL-producing and : a cross-sectional study of risk factors and comparative genomics of carriage and clinical isolates.

The global prevalence of infections caused by extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) is increasing, and for , observations indicate that this is partly driven by community-onset cases. The ESBL-E population structure in the community is scarcely described, and data on risk factors for carriage are conflicting. Here, we report the prevalence and population structure of fecal ESBL-producing and (ESBL-Ec/Kp) in a general adult population, examine risk factors, and compare carriage isolates with contemporary clinical isolates.

Antimicrobial susceptibility testing of Bacteroides species by disk diffusion: The NordicAST Bacteroides study.

Objectives: Antimicrobial susceptibility testing (AST) of anaerobic bacteria has until recently been done by MIC methods. We have carried out a multi-centre evaluation of the newly validated EUCAST disk diffusion method for AST of Bacteroides spp.

Methods: A panel of 30 Bacteroides strains was assembled based on reference agar dilution MICs, resistance gene detection and quantification of cfiA carbapenemase gene expression.

Within-patient and global evolutionary dynamics of ST17.

sequence type (ST) 17 is a global problem clone that causes multidrug-resistant (MDR) hospital infections worldwide. In 2008-2009, an outbreak of MDR ST17 occurred at a neonatal intensive care unit (NICU) in Stavanger, Norway. Fifty-seven children were colonized.

Reversible vancomycin susceptibility within emerging ST1421 Enterococcus faecium strains is associated with rearranged vanA-gene clusters and increased vanA plasmid copy number.

Vancomycin variable enterococci (VVE) are van-positive enterococci with a vancomycin-susceptible phenotype (VVE-S) that can convert to a resistant phenotype (VVE-R) and be selected for during vancomycin exposure. VVE-R outbreaks have been reported in Canada and Scandinavian countries. The aim of this study was to examine the presence of VVE in whole genome sequenced (WGS) Australian bacteremia Enterococcus faecium (Efm) isolates collected through the Australian Group on Antimicrobial resistance (AGAR) network.

Transiently silent acquired antimicrobial resistance: an emerging challenge in susceptibility testing.

Acquisition and expression of antimicrobial resistance (AMR) mechanisms in bacteria are often associated with a fitness cost. Thus, evolutionary adaptation and fitness cost compensation may support the advance of subpopulations with a silent resistance phenotype when the antibiotic selection pressure is absent. However, reports are emerging on the transient nature of silent acquired AMR, describing genetic alterations that can change the expression of these determinants to a clinically relevant level of resistance, and the association with breakthrough infections causing treatment failures.

Molecular Epidemiological Characterisation of ESBL- and Plasmid-Mediated AmpC-Producing and at Kamuzu Central Hospital, Lilongwe, Malawi.

The global rise in infections caused by multidrug resistant (MDR) Enterobacterales poses a public health problem. We have performed a molecular epidemiological characterisation of representative plasmid-mediated AmpC (pAmpC) and ESBL-positive clinical isolates of (n = 38) and (n = 17) from a tertiary hospital in Malawi collected in 2017. was the most prevalent ESBL-determinant in (n = 30/38) and (n = 17/17), whereas was detected in nearly all AmpC-phenotype (n = 15/17).

Detection of human gut carriage: a comparison of culture, qPCR, and whole metagenomic sequencing methods.

is an important opportunistic healthcare-associated pathogen and major contributor to the global spread of antimicrobial resistance. Gastrointestinal colonization with is a major predisposing risk factor for infection and forms an important hub for the dispersal of resistance. Current culture-based detection methods are time consuming, give limited intra-sample abundance and strain diversity information, and have uncertain sensitivity.

Structural basis for PoxtA-mediated resistance to phenicol and oxazolidinone antibiotics.

PoxtA and OptrA are ATP binding cassette (ABC) proteins of the F subtype (ABCF). They confer resistance to oxazolidinone and phenicol antibiotics, such as linezolid and chloramphenicol, which stall translating ribosomes when certain amino acids are present at a defined position in the nascent polypeptide chain. These proteins are often encoded on mobile genetic elements, facilitating their rapid spread amongst Gram-positive bacteria, and are thought to confer resistance by binding to the ribosome and dislodging the bound antibiotic.

Antimicrobial susceptibility profiles of clinically important bacterial pathogens at the Kamuzu Central Hospital in Lilongwe, Malawi.

Background: The aim of this prospective study was to ascertain antimicrobial resistance (AMR) in clinical bacterial pathogens from in-hospital adult patients at a tertiary hospital in Lilongwe, Malawi.

Methods: Clinical specimens (blood culture, pus, urine and cerebrospinal fluid) collected during June to December 2017 were examined for bacterial growth in standard aerobic conditions. One specimen per patient was included.

A nationwide genomic study of clinical Klebsiella pneumoniae in Norway 2001-15: introduction and spread of ESBLs facilitated by clonal groups CG15 and CG307.

Objectives: To use the nationwide Norwegian surveillance programme on resistant microbes in humans (NORM) to address longitudinal changes in the population structure of Klebsiella pneumoniae isolates from 2001-15, focusing on the emergence and dissemination of ESBL-producing K. pneumoniae in Norway.

Methods: Among blood (n = 6124) and urinary tract (n = 5496) surveillance isolates from 2001-15, we used Illumina technology to whole genome sequence 201 ESBL-producing isolates from blood (n = 130) and urine (n = 71), and 667 non-ESBL isolates from blood.

Novel genomic islands and a new vanD-subtype in the first sporadic VanD-type vancomycin resistant enterococci in Norway.

Background: Vancomycin-resistant enterococci (VRE) represent several types of transferable vancomycin resistance gene clusters. The vanD type, associated with moderate to high level vancomycin resistance, has only sporadically been described in clinical isolates. The aim of this study was to perform a genetic characterization of the first VanD-type VRE strains detected in Norway.