In:
Antimicrobial Agents and Chemotherapy, American Society for Microbiology, Vol. 45, No. 3 ( 2001-03), p. 837-844
Abstract:
Eleven environmental samples from different sources were screened for the presence of metallo-β-lactamase-producing bacteria by using a selective enrichment medium containing a carbapenem antibiotic and subsequently testing each isolate for production of EDTA-inhibitable carbapenemase activity. A total of 15 metallo-β-lactamase-producing isolates, including 10 Stenotrophomonas maltophilia isolates, 3 Chryseobacterium spp., one Aeromonas hydrophila isolate, and one Janthinobacterium lividum isolate (a species in which production of metallo-β-lactamase activity was not previously reported), were obtained from 8 samples. In the J. lividum isolate, named JAC1, production of metallo-β-lactamase activity was elicited upon exposure to β-lactams. Screening of a JAC1 genomic library for clones showing a reduced imipenem susceptibility led to the isolation of a metallo-β-lactamase determinant encoding a new member (named THIN-B) of the highly divergent subclass B3 lineage of metallo-β-lactamases. THIN-B is most closely related (35.6% identical residues) to the L1 enzyme of S. maltophilia and more distantly related to the FEZ-1 enzyme of Legionella gormanii (27.8% identity) and to the GOB-1 enzyme of Chryseobacterium meningosepticum (24.2% identity). Sequences related to bla THIN-B , and inducible production of metallo-β-lactamase activity, were also detected in the J. lividum type strain DSM1522. Expression of the bla THIN-B gene in Escherichia coli resulted in decreased susceptibility to several β-lactams, including penicillins, cephalosporins (including cephamycins and oxyimino cephalosporins), and carbapenems, revealing a broad substrate specificity of the enzyme. The results of this study indicated that metallo-β-lactamase-producing bacteria are widespread in the environment and identified a new molecular class B enzyme in the environmental species J. lividum .
Type of Medium:
Online Resource
ISSN:
0066-4804
,
1098-6596
DOI:
10.1128/AAC.45.3.837-844.2001
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2001
detail.hit.zdb_id:
1496156-8
SSG:
12
SSG:
15,3
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