Aeromonas dhakensis is not a rare cause of Aeromonas bacteremia in Hiroshima, Japan. Issue 2 (February 2020)

• Record Type: Journal Article
• Authors: Kitagawa, Hiroki; Ohge, Hiroki; Yu, Liansheng; Kayama, Shizuo; Hara, Toshinori; Kashiyama, Seiya; Kajihara, Toshiki; Hisatsune, Junzo; Sueda, Taijiro; Sugai, Motoyuki
• Is Part Of: Journal of infection and chemotherapy. Volume 26:Issue 2(2020:Feb.)
• Page Start: 316
• Page End: 320
• Publication Date: 2020-02
• Subjects: Aeromonas dhakensis -- Bacteremia -- Clinical infection -- Antimicrobial resistance; CLSI Clinical and Laboratory Standards Institute -- MALDI-TOF MS matrix-assisted laser desorption ionization-time of flight mass spectrometry -- MBL metallo-β-lactamase -- MIC minimum inhibitory concentration -- PCR polymerase chain reaction; Chemotherapy -- Periodicals; Infection -- Periodicals; Communicable diseases -- Chemotherapy -- Periodicals; 615.5805
• DOI: 10.1016/j.jiac.2019.08.020
• Languages: English
• ISSNs: 1341-321X

Abstract

Abstract: Aeromonas dhakensis, a newly recognized species, is often misidentified as A. hydrophila, A. veronii, or A. caviae by commercial phenotypic tests. Limited data about A. dhakensis are available in Japan. We retrospectively analyzed the patients with monomicrobial Aeromonas bacteremia at Hiroshima University Hospital from January 2011 to December 2017, and species re-identification was conducted using rpoD and gyrB gene sequencing and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system. Of the 19 strains from blood isolates, A. caviae (n = 9, 47.4%), A. dhakensis (n = 4, 21.1%), A. hydrophila (n = 3, 15.8%), and A. veronii (n = 3, 15.8%) were re-identified. A. dhakensis was phenotypically misidentified as A. hydrophila (n = 3, 75%) or A. sobria (n = 1, 25%). A. dhakensis was also misidentified as A. caviae (n = 2, 50%), A. hydrophila (n = 1, 25%), and A. jandaei (n = 1, 25%) in MALDI-TOF MS system. Malignancies (n = 12, 63.2%) and liver cirrhosis (n = 7, 36.8%) were common comorbidities. Biliary tract infection was the most frequent source of Aeromonas bacteremia (n = 11, 57.9%). The major source of A. dhakensis bacteremia was also biliary tract infection (n = 3, 75%), and the 14-day infection-related mortality of A. dhakensis was 25%. A. dhakensis isolates showed similar clinical characteristics, antimicrobial susceptibility, and mortality with those of other Aeromonas species isolates. This study demonstrated that A. dhakensis is not a rare cause of Aeromonas bacteremia, but is often misidentified as A. hydrophila in Hiroshima, Japan. Further studies should be conducted to identify the geographical distribution and clinical impact of A. dhakensis in Japan.