Hiroaki Kubota1, Yoshifumi Uwamino2,3, Mari Matsui4, Tsuyoshi Sekizuka5, Yasunori Suzuki1, Rumi Okuno1, Yumi Uchitani1, Tsukasa Ariyoshi1, Wataru Aoki2, Satowa Suzuki4, Makoto Kuroda5, Takayuki Shinkai1, Keiko Yokoyama1, Kenji Sadamasu1, Takeru Funakoshi6, Mitsuru Murata2, Naoki Hasegawa3, Satoshi Iwata3. 1. Department of Microbiology, Tokyo Metropolitan Institute of Public Health, 3-24-1 Hyakunincho, Shinjuku-ku, Tokyo, Japan. 2. Department of Laboratory Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan. 3. Center for Infectious Diseases and Infection Control, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan. 4. Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, 4-2-1 Aoba-cho, Higashimurayama-shi, Tokyo, Japan. 5. Pathogen Genomics Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, Japan. 6. Department of Dermatology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan.
Abstract
Objectives: A carbapenem-resistant Enterobacter cloacae complex isolated in Tokyo, Japan, produced a carbapenemase that was detected by a Carba NP test and a modified carbapenem inactivation method, but none of the 'Big Five' carbapenemase genes was detected by PCR. This study aimed to identify the carbapenemase. Methods: Carbapenemase genes were screened by WGS. Next, we generated a recombinant plasmid in which the carbapenemase gene was inserted. We also extracted the carbapenemase gene-carrying plasmid from the E. cloacae complex. The effects of both plasmids on the antibiotic susceptibility of Escherichia coli were then tested. The carbapenemase gene-carrying plasmid in the E. cloacae complex was completely sequenced. Results: A novel carbapenemase gene, blaFRI-4, encoded an amino acid sequence that was 93.2% identical to French imipenemase (FRI-1). E. coli transformed with blaFRI-4 showed reduced carbapenem susceptibility. A complete sequence of the blaFRI-4-carrying 98 508 bp IncFII/IncR plasmid (pTMTA61661) showed that blaFRI-4 and the surrounding region (18.7 kb) were duplicated. Conclusions: The FRI-4-producing E. cloacae complex was isolated in Japan, whereas all other FRI variants have been found in Europe, suggesting that the spread of FRI carbapenemases is global.
Objectives: A carbapenem-resistant Enterobacter cloacae complex isolated in Tokyo, Japan, produced a carbapenemase that was detected by a Carba NP test and a modified carbapenem inactivation method, but none of the 'Big Five' carbapenemase genes was detected by PCR. This study aimed to identify the carbapenemase. Methods: Carbapenemase genes were screened by WGS. Next, we generated a recombinant plasmid in which the carbapenemase gene was inserted. We also extracted the carbapenemase gene-carrying plasmid from the E. cloacae complex. The effects of both plasmids on the antibiotic susceptibility of Escherichia coli were then tested. The carbapenemase gene-carrying plasmid in the E. cloacae complex was completely sequenced. Results: A novel carbapenemase gene, blaFRI-4, encoded an amino acid sequence that was 93.2% identical to French imipenemase (FRI-1). E. coli transformed with blaFRI-4 showed reduced carbapenem susceptibility. A complete sequence of the blaFRI-4-carrying 98 508 bp IncFII/IncR plasmid (pTMTA61661) showed that blaFRI-4 and the surrounding region (18.7 kb) were duplicated. Conclusions: The FRI-4-producing E. cloacae complex was isolated in Japan, whereas all other FRI variants have been found in Europe, suggesting that the spread of FRI carbapenemases is global.
Authors: Michael S M Brouwer; Kamaleddin H M E Tehrani; Michel Rapallini; Yvon Geurts; Arie Kant; Frank Harders; Vida Mashayekhi; Nathaniel I Martin; Alex Bossers; Dik J Mevius; Ben Wit; Kees T Veldman Journal: Antimicrob Agents Chemother Date: 2019-05-24 Impact factor: 5.191