Unknown

Dataset Information

0

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


ABSTRACT: 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.

SUBMITTER: Nielsen KL 

PROVIDER: S-EPMC6925186 | BioStudies | 2019-01-01

REPOSITORIES: biostudies

Similar Datasets

2019-01-01 | S-EPMC6628187 | BioStudies
2014-01-01 | S-EPMC3893261 | BioStudies
2018-01-01 | S-EPMC5953442 | BioStudies
1000-01-01 | S-EPMC5605379 | BioStudies
2019-01-01 | S-EPMC6761508 | BioStudies
2019-01-01 | S-EPMC6677655 | BioStudies
2017-01-01 | S-EPMC5549755 | BioStudies
2017-01-01 | S-EPMC5487606 | BioStudies
2019-01-01 | S-EPMC6365502 | BioStudies
2015-01-01 | S-EPMC4325821 | BioStudies