Characterization of a carbapenemase-producing clinical isolate of Bacteroides fragilis in Scandinavia: genetic analysis of a unique insertion sequence.
In 2003 a Bacteroides fragilis blood culture isolate (K2-28) was recovered from a 61-y-old male with severe general atherosclerosis during treatment with meropenem. K2-28 was shown to possess a functional metallo-beta-lactamase with a reduction in imipenem MIC from 256 to 3 mg/l in the presence of EDTA using the MBL E-test strip. PCR results were for positive for the cfiA gene. Analysis of the cfiA from K2-28 revealed it was 100% identical to previously described cfiA-1 genes. Analysis of the upstream region of cfiA revealed a novel insertion sequence (IS) element, being most similar (94% identity) to IS612 recently described from Japan designating the element within the IS4 family. The element possessed a perfect terminal inverted repeat sequence at the distal ends of the IS element and provided a putative promoter for transcription of the cfiA gene. The distance between the hybrid promoter and the cfiA start codon was 158 base pairs and inserted into a different DNA sequence upstream of cfiA to that previously reported. The -10 promoter region was most similar to that of IS613 (100%) and the -35 promoter region to IS612 (100%), demonstrating the plasticity of these genetic regions.
Walsh
T R
TR
Department of Pathology and Microbiology, University of Bristol, Bristol, UK. t.r.walsh@bristol.ac.uk
Onken
A
A
Haldorsen
B
B
Toleman
M A
MA
Sundsfjord
A
A
D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D001442:Bacteroides Infections / Q000382:microbiology*; D001441:Bacteroides fragilis / Q000145:classification / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D001483:Base Sequence; D004251:DNA Transposable Elements; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D008297:Male; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008969:Molecular Sequence Data; D009664:Norway; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D017422:Sequence Analysis, DNA; D013845:Thienamycins / Q000494:pharmacology; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D013845:Thienamycins; D015378:Imipenem; D001618:beta-Lactamases; C063912:carbapenemase; D000077731:Meropenem