title: Penicillin-susceptible group B streptococcal clinical isolates with reduced cephalosporin susceptibility.
abstract: We characterized penicillin-susceptible group B streptococcal (PSGBS) clinical isolates exhibiting no growth inhibition zone around a ceftibuten disk (CTB(r) PSGBS). The CTB(r) PSGBS isolates, for which augmented MICs of cefaclor and ceftizoxime were found, shared a T394A substitution in penicillin-binding protein 2X (PBP 2X) and a T567I substitution in PBP 2B, together with an additional G429S substitution in PBP 2X or a T145A substitution in PBP 1A, although the T145A substitution in the transglycosidase domain of PBP 1A would have no effect on the level of resistance to ceftibuten.
authors.affiliation: Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan Medical Microbiology Laboratory, Funabashi Municipal Medical Center, Funabashi, Chiba, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Nagano
authors.affiliation: Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Nagano
authors.affiliation: Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan Medical Microbiology Laboratory, Funabashi Municipal Medical Center, Funabashi, Chiba, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Toyama
authors.affiliation: Department of Bacteriology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Aichi, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Kimura
authors.affiliation: Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Keigo
authors.initials: K
authors.lastname: Shibayama
authors.affiliation: Department of Bacteriology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Aichi, Japan yarakawa@med.nagoya-u.ac.jp.
authors.forename: Yoshichika
authors.initials: Y
authors.lastname: Arakawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019943:Amino Acid Substitution; D019881:Aminoacyltransferases / Q000235:genetics; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D046915:Penicillin-Binding Proteins / Q000235:genetics; D010406:Penicillins / Q000494:pharmacology*; D017422:Sequence Analysis, DNA; D013290:Streptococcal Infections / Q000382:microbiology*; D013292:Streptococcus agalactiae / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D004269:DNA, Bacterial; D046915:Penicillin-Binding Proteins; D010406:Penicillins; C072223:PBP 2x protein, Streptococcus; D019881:Aminoacyltransferases; C478701:penicillin-binding protein 2b, Streptococcus