Genetic diversity of carbapenem-hydrolyzing metallo-beta-lactamases from Chryseobacterium (Flavobacterium) indologenes.
The class B carbapenem-hydrolyzing beta-lactamase IND-1 has been characterized for Chryseobacterium indologenes strain 001. With internal primers for the bla gene for IND-1 (bla(IND-1)) and an internal bla(IND-1) probe, PCR amplifications failed, while hybridization results were positive when DNA from another C. indologenes isolate, strain CIP101026, was used as a template. Thus, a bla(IND)-related gene was cloned from this C. indologenes reference strain. Sequencing of the insert of a recombinant plasmid conferring resistance to carbapenems revealed an open reading frame with a G + C content of 39.9% and coding for a 243-amino-acid preprotein named IND-2. IND-2 shared 80% amino acid identity with IND-1 and had a similar broad-spectrum resistance profile, including resistance to carbapenems. It was classified in functional subgroup 3a of class B carbapenem-hydrolyzing beta-lactamases. IND-1 and IND-2, despite their genetic diversity, possessed similar kinetic parameters, except that ceftazidime was hydrolyzed less by IND-2. To obtain the entire bla(IND)-related gene sequences of eight other C. indologenes isolates, PCR was performed using internal and external primers, followed by inverse PCR techniques. The likely chromosome-mediated metallo-beta-lactamases of the 10 C. indologenes isolates were divided into several groups and subgroups. IND-1, IND-2, IND-2a, IND-3, and IND-4 shared 77 to 99% amino acid identity.
Bellais
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S
Service de Bactériologie-Virologie, Hôpital de Bicêtre, Assistance Publique-Hôpitaux de Paris, Faculté de Médecine Paris-Sud, 94275 Le Kremlin-Bicêtre Cedex, France.
Poirel
L
L
Leotard
S
S
Naas
T
T
Nordmann
P
P
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015780:Carbapenems / Q000378:metabolism; D005417:Flavobacterium / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D014644:Genetic Variation; D006801:Humans; D006868:Hydrolysis; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
D000900:Anti-Bacterial Agents; D015780:Carbapenems; D001618:beta-Lactamases