Integration of a transposon Tn1-encoded inhibitor-resistant beta-lactamase gene, bla(TEM-67) from Proteus mirabilis, into the Escherichia coli chromosome.
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.
Naas
Thierry
T
Service de Bactériologie-Virologie, Hôpital de Bicêtre, Assistance Publique-Hôpitaux de Paris, Faculté de Médecine Paris-Sud, 94275 Le Kremlin-Bicêtre, France. thierry.naas@bct.ap-hop-paris.fr
Zerbib
Marie
M
Girlich
Delphine
D
Nordmann
Patrice
P
D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D004251:DNA Transposable Elements; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000235:genetics*; D005260:Female; D006801:Humans; D010957:Plasmids; D011513:Proteus mirabilis / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D001618:beta-Lactamases / Q000235:genetics*
D004251:DNA Transposable Elements; D001618:beta-Lactamases