Mutational change of CTX-M-15 to CTX-M-127 resulting in mecillinam resistant Escherichia coli during pivmecillinam treatment of a patient.

Pivmecillinam (amdinocillin pivoxil) is the recommended first-choice antibiotic used to treat urinary tract infections (UTIs) in Denmark. The frequency of mutation to mecillinam (MEC) resistance is described as high in vitro; however, treatment of UTI has a good clinical response and prevalence of mecillinam resistance in Escherichia coli remains low despite many years of use. We describe occurrence of in vivo mecillinam resistance in a clinical isolate of ESBL-producing E.

Genome-wide-analyses of Listeria monocytogenes from food-processing plants reveal clonal diversity and date the emergence of persisting sequence types.

Whole genome sequencing is increasing used in epidemiology, e.g. for tracing outbreaks of food-borne diseases.

Evidence for the evolutionary steps leading to mecA-mediated β-lactam resistance in staphylococci.

The epidemiologically most important mechanism of antibiotic resistance in Staphylococcus aureus is associated with mecA-an acquired gene encoding an extra penicillin-binding protein (PBP2a) with low affinity to virtually all β-lactams. The introduction of mecA into the S. aureus chromosome has led to the emergence of methicillin-resistant S.

Evolutionary Origin of the Staphylococcal Cassette Chromosome (SCC).

Several lines of evidence indicate that the most primitive staphylococcal species, those of the group, were involved in the first stages of evolution of the staphylococcal cassette chromosome (SCC), the genetic element carrying the β-lactam resistance gene However, many steps are still missing from this evolutionary history. In particular, it is not known how was incorporated into the mobile element SCC prior to dissemination among and other pathogenic staphylococcal species. To gain insights into the possible contribution of several species of the group to the assembly of SCC, we sequenced the genomes of 106 isolates, comprising ( = 76), ( = 18), and ( = 12) from animal and human sources, and characterized the native location of and the SCC insertion site by using a variety of comparative genomic approaches.

Host-Specific Patterns of Genetic Diversity among IncI1-Iγ and IncK Plasmids Encoding CMY-2 β-Lactamase in Escherichia coli Isolates from Humans, Poultry Meat, Poultry, and Dogs in Denmark.

Unlabelled: CMY-2 is the most common plasmid-mediated AmpC β-lactamase in Escherichia coli isolates of human and animal origin. The aim of this study was to elucidate the epidemiology of CMY-2-producing E. coli in Denmark.

Fatal Septicemia Linked to Transmission of MRSA Clonal Complex 398 in Hospital and Nursing Home, Denmark.

We describe 2 fatal cases of methicillin-resistant Staphylococcus aureus (MRSA) clonal complex 398 septicemia in persons who had no contact with livestock. Whole-genome sequencing of the isolated MRSA strains strongly suggest that both were of animal origin and that the patients had been infected through 2 independent person-to-person transmission chains.

"Population structure of drug-susceptible,-resistant and ESBL-producing Escherichia coli from community-acquired urinary tract".

Background: Escherichia coli is the most common cause of urinary tract infection (UTI). The pathogenic isolates are becoming increasingly resistant to antibiotics; with a worldwide dissemination of resistant sequence types (ST). We characterized three different uropathogenic E.

The Soil Microbiota Harbors a Diversity of Carbapenem-Hydrolyzing β-Lactamases of Potential Clinical Relevance.

The origin of carbapenem-hydrolyzing metallo-β-lactamases (MBLs) acquired by clinical bacteria is largely unknown. We investigated the frequency, host range, diversity, and functionality of MBLs in the soil microbiota. Twenty-five soil samples of different types and geographical origins were analyzed by antimicrobial selective culture, followed by phenotypic testing and expression of MBL-encoding genes in Escherichia coli, and whole-genome sequencing of MBL-producing strains was performed.

The new macrolide-lincosamide-streptogramin B resistance gene erm(45) is located within a genomic island in Staphylococcus fleurettii.

Genome alignment of a macrolide, lincosamide, and streptogramin B (MLSB)-resistant Staphylococcus fleurettii strain with an MLSB-susceptible S. fleurettii strain revealed a novel 11,513-bp genomic island carrying the new erythromycin resistance methylase gene erm(45). This gene was shown to confer inducible MLSB resistance when cloned into Staphylococcus aureus.

Comparing whole-genome sequencing with Sanger sequencing for spa typing of methicillin-resistant Staphylococcus aureus.

spa typing of methicillin-resistant Staphylococcus aureus (MRSA) has traditionally been done by PCR amplification and Sanger sequencing of the spa repeat region. At Hvidovre Hospital, Denmark, whole-genome sequencing (WGS) of all MRSA isolates has been performed routinely since January 2013, and an in-house analysis pipeline determines the spa types. Due to national surveillance, all MRSA isolates are sent to Statens Serum Institut, where the spa type is determined by PCR and Sanger sequencing.

Using MALDI-TOF mass spectrometry as a rapid and accurate diagnostic tool in infective endocarditis: a case report of a patient with mitral valve infective endocarditis caused by Abiotrophia defectiva.

A case of infective endocarditis caused by Abiotrophia defectiva is presented. The use of MALDI-TOF mass spectrometry as a rapid and accurate diagnostic tool in infective endocarditis is discussed.

Prevalence and molecular characterization of clinical isolates of Escherichia coli expressing an AmpC phenotype.

Objectives: To establish the prevalence of the AmpC beta-lactamase phenotype in clinical isolates of Escherichia coli and characterize the genetic resistance mechanisms causing the observed phenotype.

Methods: Clinical E. coli (n = 74) with reduced susceptibility to third-generation cephalosporins and resistance to cefoxitin were collected from the Department of Clinical Microbiology at Hvidovre Hospital, Denmark, in 2006.