Sohei Harada1,2, Kotaro Aoki3, Daisuke Ohkushi4, Koh Okamoto5, Kazumi Takehana6, Tomomi Akatsuchi7, Keito Ida7, Daigo Shoji7,8, Yoshikazu Ishii3, Yohei Doi9,10, Kyoji Moriya11,5, Brian Hayama4,7. 1. Department of Infection Control and Prevention, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. haradas-tky@umin.ac.jp. 2. Department of Infectious Diseases, Cancer Institute Hospital, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan. haradas-tky@umin.ac.jp. 3. Department of Microbiology and Infectious Diseases, Toho University School of Medicine, 5-21-16 Omori-nishi, Ota-ku, Tokyo, 143-8540, Japan. 4. Department of Infectious Diseases, Cancer Institute Hospital, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan. 5. Department of Infectious Diseases, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. 6. Clinical Laboratory, Cancer Institute Hospital, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan. 7. Department of Infection Prevention, Cancer Institute Hospital, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan. 8. Department of Pharmacy, Cancer Institute Hospital, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan. 9. Department of Infectious Diseases, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan. 10. Division of Infectious Diseases, University of Pittsburgh School of Medicine, 3550 Terrace Street, Pittsburgh, PA, 15261, USA. 11. Department of Infection Control and Prevention, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
Abstract
BACKGROUND: Information about the clinical and microbiological characteristics of IMP-producing Enterobacterales has been limited. Here, we describe an institutional outbreak of IMP-producing Enterobacter cloacae complex (ECC) involving multiple clades of ECC sequence type (ST) 78 strains. METHODS: Antimicrobial susceptibility testing, whole-genome sequencing, and conjugation experiments of 18 IMP-producing ECC strains isolated during four-year study period were performed. Species and subspecies were determined by average nucleotide identity analysis and clonal relatedness of the isolates was analyzed with multilocus sequence typing and core-genome single nucleotide polymorphism (SNP) analysis. Relevant clinical information was extracted from medical records. RESULTS: Fourteen of 18 IMP-producing ECC isolates were determined as Enterobacter hormaechei ST78. Sixteen isolates, including 13 isolates belonging to ST78, carried blaIMP-1 in In316-like class 1 integron and also carried IncHI2 plasmids. Conjugation experiments were successful for 12 isolates carrying blaIMP-1 on IncHI2 plasmids and for an isolate carrying blaIMP-11 on an IncL/M plasmid. Although isolation of ST78 strains was clustered in a 14-months period suggesting nosocomial transmission, these strains were subdivided into three clades by SNP analysis: clade A (n = 10), clade B (n = 1), clade C (n = 3). A part of clonal relatedness was unexpected by the epidemiological information at the time of isolation of the strains. Most of the IMP-producing ECC strains were susceptible to non-β-lactam antibiotics and had relatively low minimum inhibitory concentrations to carbapenems (≤4 μg/mL). Five of six infections caused by IMP-producing ECC were treated successfully. CONCLUSIONS: Whole-genome sequencing analysis revealed the outbreak was caused by three different clades of ST78 strains, where patients had favorable treatment outcome of the infections compared with that caused by Enterobacterales producing other carbapenemases, possibly due to their non-multidrug-resistant phenotype.
BACKGROUND: Information about the clinical and microbiological characteristics of IMP-producing Enterobacterales has been limited. Here, we describe an institutional outbreak of IMP-producing Enterobacter cloacae complex (ECC) involving multiple clades of ECC sequence type (ST) 78 strains. METHODS: Antimicrobial susceptibility testing, whole-genome sequencing, and conjugation experiments of 18 IMP-producing ECC strains isolated during four-year study period were performed. Species and subspecies were determined by average nucleotide identity analysis and clonal relatedness of the isolates was analyzed with multilocus sequence typing and core-genome single nucleotide polymorphism (SNP) analysis. Relevant clinical information was extracted from medical records. RESULTS: Fourteen of 18 IMP-producing ECC isolates were determined as Enterobacter hormaechei ST78. Sixteen isolates, including 13 isolates belonging to ST78, carried blaIMP-1 in In316-like class 1 integron and also carried IncHI2 plasmids. Conjugation experiments were successful for 12 isolates carrying blaIMP-1 on IncHI2 plasmids and for an isolate carrying blaIMP-11 on an IncL/M plasmid. Although isolation of ST78 strains was clustered in a 14-months period suggesting nosocomial transmission, these strains were subdivided into three clades by SNP analysis: clade A (n = 10), clade B (n = 1), clade C (n = 3). A part of clonal relatedness was unexpected by the epidemiological information at the time of isolation of the strains. Most of the IMP-producing ECC strains were susceptible to non-β-lactam antibiotics and had relatively low minimum inhibitory concentrations to carbapenems (≤4 μg/mL). Five of six infections caused by IMP-producing ECC were treated successfully. CONCLUSIONS: Whole-genome sequencing analysis revealed the outbreak was caused by three different clades of ST78 strains, where patients had favorable treatment outcome of the infections compared with that caused by Enterobacterales producing other carbapenemases, possibly due to their non-multidrug-resistant phenotype.
Authors: Yasufumi Matsumura; Gisele Peirano; Mary R Motyl; Mark D Adams; Liang Chen; Barry Kreiswirth; Rebekah DeVinney; Johann D D Pitout Journal: Antimicrob Agents Chemother Date: 2017-03-24 Impact factor: 5.191
Authors: Amy J Mathers; Heather L Cox; Brandon Kitchel; Hugo Bonatti; Ann Karen C Brassinga; Joanne Carroll; W Michael Scheld; Kevin C Hazen; Costi D Sifri Journal: MBio Date: 2011-11-01 Impact factor: 7.867
Authors: Leah W Roberts; Patrick N A Harris; Brian M Forde; Nouri L Ben Zakour; Elizabeth Catchpoole; Mitchell Stanton-Cook; Minh-Duy Phan; Hanna E Sidjabat; Haakon Bergh; Claire Heney; Jayde A Gawthorne; Jeffrey Lipman; Anthony Allworth; Kok-Gan Chan; Teik Min Chong; Wai-Fong Yin; Mark A Schembri; David L Paterson; Scott A Beatson Journal: Nat Commun Date: 2020-01-24 Impact factor: 14.919
Authors: Gisele Peirano; Yasufumi Matsumura; Mark D Adams; Patricia Bradford; Mary Motyl; Liang Chen; Barry N Kreiswirth; Johann D D Pitout Journal: Emerg Infect Dis Date: 2018-06 Impact factor: 6.883
Authors: C Mullié; D Lemonnier; C C Adjidé; J Maizel; G Mismacque; A Cappe; T Carles; M Pierson-Marchandise; Y Zerbib Journal: J Hosp Infect Date: 2021-11-30 Impact factor: 3.926