Open AccessIntegration of a Transposon Tn 1 -Encoded Inhibitor-Resistant β-Lactamase Gene, bla TEM-67 from Proteus mirabilis , into the Escherichia coli Chromosome
Author(s) -
Thierry Naas,
Marie Zerbib,
Delphine Girlich,
Patrice Nordmann
Publication year - 2003
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.47.1.19-26.2003
Subject(s) - proteus mirabilis , plasmid , biology , transposable element , escherichia coli , microbiology and biotechnology , colicin , amplicon , southern blot , insertion sequence , gene , genetics , mutant , polymerase chain reaction
Proteus mirabilis NEL-1 was isolated from a urine sample of a patient hospitalized in a long-term care facility. Strain NEL-1 produced a beta-lactamase with a pI of 5.2 conferring resistance to amoxicillin and amoxicillin-clavulanic acid. Sequencing of a PCR amplicon by using TEM-specific primers revealed a novel bla(TEM) gene, bla(TEM-67). TEM-67 was an IRT-1-like TEM derivative related to TEM-65 (Lys39, Cys244) with an additional Leu21Ile amino acid substitution in the leader peptide. The biochemical properties of TEM-67 were equivalent to those described for TEM-65. Analysis of sequences surrounding bla(TEM-67) revealed that it was located on a transposon, Tn1, which itself was located on a 48-kb non-self-transferable plasmid, pANG-1. Electroporation of plasmid pANG-1 into Escherichia coli DH10B resulted in the integration of bla(TEM-67) into the chromosome, whereas it remained episomal in the P. mirabilis CIP103181 reference strain. Further characterization of pANG-1 revealed the presence of two identical sequences on both sides of Tn1 that contained an IS26 insertion sequence followed by a novel colicin gene, colZ, which had 20% amino acid identity with other colicin genes. The characterization of this novel TEM derivative provides further evidence for the large diversity of plasmid-encoded beta-lactamases produced in P. mirabilis and for their spread to other enterobacterial species through transposable-element-mediated events.