title: The indirect pathogenicity of Stenotrophomonas maltophilia.
abstract: Stenotrophomonas maltophilia has at least two inducible beta-lactamases, L1 and L2, which can hydrolyze almost all classes of beta-lactam antimicrobial agents. This study was done to verify the indirect pathogenicity of S. maltophilia that could promote the growth of other beta-lactam agent-susceptible bacteria in a mixed culture. We counted CFU of beta-lactam agent-susceptible bacteria under the presence of imipenem or ceftazidime in a pure culture and mixed culture with S. maltophilia. Our results showed that beta-lactamase leaking from S. maltophilia can encourage the growth of Serratia marcescens and Pseudomonas aeruginosa even if imipenem or ceftazidime was supplemented. This study discovered a blind spot in chemotherapy against an indirect pathogen such as S. maltophilia.
authors.affiliation: Department of Microbiology and Pathology, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago 683-8503, Japan. dkataoka@grape.med.tottori-u.ac.jp
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kataoka
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kawakami
authors.forename: Yuko
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Ayako
authors.initials: A
authors.lastname: Tanimoto
authors.forename: Shiro
authors.initials: S
authors.lastname: Ikawa
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D018920:Coculture Techniques; D015169:Colony Count, Microbial; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development; D012706:Serratia marcescens / Q000187:drug effects / Q000254:growth & development; D020615:Stenotrophomonas maltophilia / Q000187:drug effects / Q000201:enzymology / Q000472:pathogenicity*; D014774:Virulence; D001618:beta-Lactamases / Q000378:metabolism; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; C088032:beta-lactamase L1; C425104:beta-lactamase L2; D001618:beta-Lactamases