title: An outbreak of blaOXA-51-like- and blaOXA-66-positive Acinetobacter baumannii ST208 in the emergency intensive care unit.
abstract: A series of clinical isolates of drug-resistant (DR) Acinetobacter baumannii with diverse drug susceptibility was detected from eight patients in the emergency intensive care unit of Tokai University Hospital. The initial isolate was obtained in March 2010 (A. baumannii Tokai strain 1); subsequently, seven isolates were obtained from patients (A. baumannii Tokai strains 2-8) and one isolate was obtained from an air-fluidized bed used by five of the patients during the 3 months from August to November 2011. The isolates were classified into three types of antimicrobial drug resistance patterns (RRR, SRR and SSR) according to their susceptibility (S) or resistance (R) to imipenem, amikacin and ciprofloxacin, respectively. Genotyping of these isolates by multilocus sequence typing revealed one sequence type, ST208, whilst that by a DiversiLab analysis revealed two subtypes. All the isolates were positive for blaOXA-51-like and blaOXA-66, as assessed by PCR and DNA sequencing. A. baumannii Tokai strains 1-8 and 10 (RRR, SRR and SSR) had quinolone resistance-associated mutations in gyrA/parC, as revealed by DNA sequencing. The ISAba1 upstream of blaOXA-51-like and aminoglycoside resistance-associated gene, armA, were detected in A. baumannii Tokai strains 1-7 and 10 (RRR and SRR) as assessed by PCR. Among the genes encoding resistance-nodulation-division family pumps (adeB, adeG and adeJ) and outer-membrane porins (oprD and carO), overexpression of adeB and adeJ and suppression of oprD and carO were seen in isolates of A. baumannii Tokai strain 2 (RRR), as assessed by real-time PCR. Thus, the molecular characterization of a series of isolates of DR A. baumannii revealed the outbreak of ST208 and diverse antimicrobial drug susceptibilities, which almost correlated with differential gene alterations responsible for each type of drug resistance.
authors.affiliation: Infection Control Division, Tokai University Hospital, 143 Shimokasuya, Isehara 259-1193, Japan.|Department of Laboratory Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara 259-1193, Japan.
authors.forename: Satomi
authors.initials: S
authors.lastname: Asai
authors.affiliation: Department of Critical Care and Emergency Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara 259-1193, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Umezawa
authors.affiliation: Department of Laboratory Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara 259-1193, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Iwashita
authors.affiliation: Infection Control Division, Tokai University Hospital, 143 Shimokasuya, Isehara 259-1193, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Ohshima
authors.affiliation: Infection Control Division, Tokai University Hospital, 143 Shimokasuya, Isehara 259-1193, Japan.
authors.forename: Maya
authors.initials: M
authors.lastname: Ohashi
authors.affiliation: Infection Control Division, Tokai University Hospital, 143 Shimokasuya, Isehara 259-1193, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Sasaki
authors.affiliation: Support Center for Medical Research and Education, Tokai University School of Medicine, 143 Shimokasuya, Isehara 259-1193, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Hayashi
authors.affiliation: Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Matsui
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 Critical Care and Emergency Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara 259-1193, Japan.
authors.forename: Sadaki
authors.initials: S
authors.lastname: Inokuchi
authors.affiliation: Infection Control Division, Tokai University Hospital, 143 Shimokasuya, Isehara 259-1193, Japan.|Department of Laboratory Medicine, Tokai University School of Medicine, 143 Shimokasuya, Isehara 259-1193, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Miyachi
mesh_terms: D000151:Acinetobacter Infections / Q000453:epidemiology / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004196:Disease Outbreaks; D024881:Drug Resistance, Bacterial; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D006801:Humans; D007362:Intensive Care Units; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases