Research
Print page Print page
Switch language
The Capital Region of Denmark - a part of Copenhagen University Hospital
E-pub ahead of print

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

Research output: Contribution to journalJournal articleResearchpeer-review

DOI

  1. ESBL-production in Escherichia coli and Klebsiella pneumoniae isolates from Nigeria

    Research output: Contribution to journalJournal articleResearchpeer-review

  2. A mariner transposon vector adapted for mutagenesis in oral streptococci

    Research output: Contribution to journalJournal articleResearchpeer-review

  1. Community-acquired meningitis caused by beta-haemolytic streptococci in adults: a nationwide population-based cohort study

    Research output: Contribution to journalJournal articleResearchpeer-review

  2. Resistance to piperacillin/tazobactam in Escherichia coli resulting from extensive IS26-associated gene amplification of blaTEM-1

    Research output: Contribution to journalJournal articleResearchpeer-review

  3. Genome Sequence of an Unknown Subtype of Hepatitis C Virus Genotype 6: Another Piece for the Taxonomic Puzzle

    Research output: Contribution to journalJournal articleResearchpeer-review

  4. LISTERIA MENINGITIS IN DANISH CHILDREN 2000-2017: A Rare Event Even in a Country With High Rates of Invasive Listeriosis

    Research output: Contribution to journalJournal articleResearchpeer-review

  5. ESBL-production in Escherichia coli and Klebsiella pneumoniae isolates from Nigeria

    Research output: Contribution to journalJournal articleResearchpeer-review

View graph of relations

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. coli following pivmecillinam treatment. The identified phenotypic differences in the mecillinam resistant isolate compared with the original mecillinam susceptible isolate were a full-length LPS with O-antigen (O25), mecillinam resistance and a lower MIC for ceftazidime. Regarding genotype, the resistant isolate differed with a mutation in blaCTX-M-15 to blaCTX-M-127 , loss of a part of a plasmid and a genomic island, respectively, and insertion of a transposase in wbbL, causing the rough phenotype. The observed mecillinam resistance is expected to be caused by the mutation in blaCTX-M-15 with additional contribute from the serotype shift. We continue to recommend the use of pivmecillinam as first-line treatment for UTI.

Original languageEnglish
Article numbere941
JournalMicrobiologyOpen
ISSN2045-8827
DOIs
Publication statusE-pub ahead of print - 1 Oct 2019

    Research areas

  • Escherichia coli, LPS, mecillinam, metabolism, mutation, O-antigen, Pivmecillinam, resistance, serotype, whole-genome sequencing

ID: 58060601