Loading…

Characterization of the plasmid-mediated β-lactamase in Branhamella catarrhalis, with special reference to substrate affinity

The plasmid-mediated Branhamella catarrhalis β-lactamase BRO-1, also found in Moraxella nonliquefaciens, was characterized as regards substrate profile, isoelectric point and relative substrate affinity index (RSAI) to various substrates and compared in these aspects with the TEM-1 enzyme of Haemoph...

Full description

Saved in:
Bibliographic Details
Published in:Journal of antimicrobial chemotherapy 1985-02, Vol.15 (2), p.139-149
Main Authors: Eliasson, Ingvar, Kamme, Carl
Format: Article
Language:English
Subjects:
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The plasmid-mediated Branhamella catarrhalis β-lactamase BRO-1, also found in Moraxella nonliquefaciens, was characterized as regards substrate profile, isoelectric point and relative substrate affinity index (RSAI) to various substrates and compared in these aspects with the TEM-1 enzyme of Haemophilus influenzae. As measured by a biological assay and with high performance liquid chromatography (HPLQ, BRO-1was found to hydrolyse carbenicillin, mecillinam, methicillin and cefaclor with a higher rate than TEM-1. The only substrates having a relative rate of hydrolysis higher for TEM-1 than for BRO-1 were ampicillin and cephaloridine. The rates of hydrolysis registered with these two methods wei-e comparable for all but 2 of 13 tested substrates. Isoelectric focusing yielded a main band at pH 5-6 and several satellite bands consistent with those reported by other authors for BranhameUa enzymes having a substrate profile similar to that of BRO-1. A tenfold or higher difference in SAI between BRO-1 and TEM-1 was recorded for five of the 15 compounds tested. BRO-1 seems to be the most common β-lactamase in Bran, catarrhalis, irrespective of geographic origin. Its substrate profile, isoelectric pattern and RSAI differ from those of other known plasmid-mediated β-lactamases described, thus justifying a specific esignation.
ISSN:0305-7453
1460-2091
DOI:10.1093/jac/15.2.139