scholarly journals Institutional outbreak involving multiple clades of IMP-producing Enterobacter cloacae complex sequence type 78 at a cancer center in Tokyo, Japan

2020 ◽  
Author(s):  
Sohei Harada ◽  
Kotaro Aoki ◽  
Daisuke Ohkushi ◽  
Koh Okamoto ◽  
Kazumi Takehana ◽  
...  

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. Twelve isolates, including 10 isolates belonging to ST78, carried blaIMP-1 in In316-like class 1 integron located on 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 16-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). Four of five 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.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sohei Harada ◽  
Kotaro Aoki ◽  
Daisuke Ohkushi ◽  
Koh Okamoto ◽  
Kazumi Takehana ◽  
...  

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.


2021 ◽  
Author(s):  
Sohei Harada ◽  
Kotaro Aoki ◽  
Daisuke Ohkushi ◽  
Koh Okamoto ◽  
Kazumi Takehana ◽  
...  

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-b-lactam antibiotics and had relatively low minimum inhibitory concentrations to carbapenems (£4 mg/mL). Four of five 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.


2018 ◽  
Vol 62 (12) ◽  
Author(s):  
Joshua B. Daniels ◽  
Liang Chen ◽  
Susan V. Grooters ◽  
Dixie F. Mollenkopf ◽  
Dimitria A. Mathys ◽  
...  

ABSTRACT Companion animals are likely relevant in the transmission of antimicrobial-resistant bacteria. Enterobacter xiangfangensis sequence type 171 (ST171), a clone that has been implicated in clusters of infections in humans, was isolated from two dogs with clinical disease in Ohio. The canine isolates contained IncHI2 plasmids encoding blaKPC-4. Whole-genome sequencing was used to put the canine isolates in phylogenetic context with available human ST171 sequences, as well as to characterize their blaKPC-4 plasmids.


2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Tse H. Koh ◽  
Nurdyana Binte Abdul Rahman ◽  
Jeanette W. P. Teo ◽  
My-Van La ◽  
Balamurugan Periaswamy ◽  
...  

ABSTRACT Whole-genome sequencing was performed on 16 isolates of the carbapenemase-producing Enterobacter cloacae complex to determine the flanking regions of bla IMI-type genes. Phylogenetic analysis of multilocus sequence typing (MLST) targets separated the isolates into 4 clusters. The bla IMI-type genes were all found on Xer-dependent integrative mobile elements (IMEX). The IMEX elements of 5 isolates were similar to those described in Canada, while the remainder were novel. Five isolates had IMEX elements lacking a resolvase and recombinase.


Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 201
Author(s):  
Sang Mee Hwang ◽  
Hee Won Cho ◽  
Tae Yeul Kim ◽  
Jeong Su Park ◽  
Jongtak Jung ◽  
...  

Carbapenem-resistant Acinetobacter baumannii (CRAB) outbreaks in hospital settings challenge the treatment of patients and infection control. Understanding the relatedness of clinical isolates is important in distinguishing outbreak isolates from sporadic cases. This study investigated 11 CRAB isolates from a hospital outbreak by whole-genome sequencing (WGS), utilizing various bioinformatics tools for outbreak analysis. The results of multilocus sequence typing (MLST), single nucleotide polymorphism (SNP) analysis, and phylogenetic tree analysis by WGS through web-based tools were compared, and repetitive element polymerase chain reaction (rep-PCR) typing was performed. Through the WGS of 11 A. baumannii isolates, three clonal lineages were identified from the outbreak. The coexistence of blaOXA-23, blaOXA-66, blaADC-25, and armA with additional aminoglycoside-inactivating enzymes, predicted to confer multidrug resistance, was identified in all isolates. The MLST Oxford scheme identified three types (ST191, ST369, and ST451), and, through whole-genome MLST and whole-genome SNP analyses, different clones were found to exist within the MLST types. wgSNP showed the highest discriminatory power with the lowest similarities among the isolates. Using the various bioinformatics tools for WGS, CRAB outbreak analysis was applicable and identified three discrete clusters differentiating the separate epidemiologic relationships among the isolates.


Sign in / Sign up

Export Citation Format

Share Document