Mechanisms of resistance to imipenem in imipenem‐resistant, ampicillin‐sensitive Enterococcus faecium

$48.00 plus tax (Refund Policy)

Download / Buy Article:

Abstract:

Enterococcus faecium has six penicillin‐binding proteins (PBP), where PBP5 seems to be the main target for β‐lactam antibiotics. The PBP profiles of three imipenem‐resistant, ampicillin‐sensitive E. faecium strains, isolated from the same patient, were studied using biotinylated ampicillin and chemiluminescence detection. Imipenem resistance in these strains was found to be associated with hyperproduction of PBP5 compared to the ampicillin‐ and imipenem‐susceptible strain ATCC 19434. PBP5 in the imipenem‐resistant strains (S1, B2) exhibited a selectively decreased affinity for imipenem. An 854 bp DNA fragment, corresponding to the penicillin‐binding domain of pbp5fm, was studied in the resistant strains and the reference strain. Four amino acid substitutions were observed in the resistant strains compared to the susceptible one. The contribution of these substitutions to the increased production of PBP5 in these strains is unclear since the substitution was observed also in a strain without increased production of PBP5. Our results suggest that the moderate imipenem resistance observed in these strains is associated with increased production of PBP5 with relatively decreased affinity for imipenem, and that evolution of imipenem resistance in E. faecium is dinstinct from that of the other β‐lactams such as ampicillin.

Document Type: Original Article

DOI: http://dx.doi.org/10.1034/j.1600-0463.2001.d01-148.x

Affiliations: 1: Division of Clinical Bacteriology, and 2: Center for Infectious Diseases, Huddinge University Hospital, Stockholm, Sweden

Publication date: November 1, 2001

Related content

Tools

Favourites

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more