[Rinsho Byori 51 : 201`207, 2003]

Detection of Novel Nucleotide Substitutions Resulting Amino Acid Substitutions
in TEM Type b -Lactamase Gene Isolated from a Clinically Isolated
Extended Spectrum b -Lactamases(ESBLs) Productive Escherichia Coli

Tsutomu YASUHARA, MD*1, Kunihiko FUKUCHI, MD*2,
Yasushi TAKAGI, MD*3 and Kunihide GOMI, MD*4


We screened Escherichia coli (E. coli) from specimens submitted to the Showa University hospital clinical laboratory that showed an advanced resistance to third generation cephems(Cefotaxime or Ceftazidime), as candidate extended spectrum ƒÀ-lactamases(ESBLs) producing strains. Among the candidates, two strains showed the characteristics of class A ESBLs in their susceptibility to Cefmetazole, a second generation cephem, and their resistance was inhibited by the addition of clavulanic acid. Further, we detected the TEM-type gene in one of the two E. coli strains. By determining the nucleotide sequence of the whole coding region of the TEM gene, two nucleotide substitutions with amino acid substitutions 82ValšIle, and 182AlašVal were identified.

*1Department of Clinical Pathology, Showa University, School of Medicine, Shinagawa-ku, Tokyo 142-8666