title: Clinical isolates of Nocardia brasiliensis from Japan exhibit variable susceptibility to the antibiotic imipenem.
abstract: Clinical isolates of Nocardia brasiliensis from Japan were classified into two groups based on their susceptibility to the carbapenem antibiotic, imipenem (IPM). Of 33 strains tested, 10 belonged to an IPM susceptible group, with MIC of from 0.25 to 2 microg/ml and a MIC(80) value of 1.5 microg/ml for this antibiotic. The remaining 23 strains belonged to an IPM resistant group with MIC and MIC(80) values of 8-16 microg/ml and >16 microg/ml, respectively. The type strain of N. brasiliensis belonged to this resistant group. Analysis of 16S rDNA genes sequences showed that the IPM susceptible group had characteristic single nucleotide substitutions at positions 103 (T), 381 (A), and 456 (A), in contrast to the IPM resistant group. This grouping, however, was not associated with their clinical manifestation.
authors.affiliation: Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University, 1-8-1, Inohana, Chuo-ku, 260-8673, Chiba, Japan, mikami@myco.pf.chiba-u.ac.jp.
authors.forename: Akiko
authors.initials: A
authors.lastname: Kageyama
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Hoshino
authors.forename: Masaharu
authors.initials: M
authors.lastname: Watanabe
authors.forename: Katsukiyo
authors.initials: K
authors.lastname: Yazawa
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Mikami
mesh_terms: D006801:Humans; D015378:Imipenem / Q000494:pharmacology*; D007564:Japan; D008826:Microbial Sensitivity Tests; D009615:Nocardia / Q000187:drug effects* / Q000235:genetics
chemical_list: D015378:Imipenem