Abstract
Background: Carbapenemase-producing Enterobacteriaceae (CPE) are an emerging threat in healthcare settings worldwide. Objectives: We evaluated the presence of carbapenemase genes in CPE in a tertiary care university hospital in Tokyo, Japan. Methods: Carbapenem-resistant clinical isolates were collected in 2018 at Teikyo University Hospital (Tokyo, Japan). Bacterial species were identified using MALDI-TOF MS. Carbapenemase production was evaluated using a carbapenemase inactivation method. The presence of carbapenemase genes was confirmed by multiplex PCR and DNA sequencing. Results: Four CPE isolates were identified: two Enterobacter cloacae complex strains and Klebsiella oxytoca and Klebsiella pneumoniae strains. Three of the isolates (E. cloacae complex and K. oxytoca) were IMP-1-type producers, including IMP-10 in their produced metallo-β-lactamase, and are epidemic in East Japan. The IMP-10-producing E. cloacae complex strain also produced CTX-M ESBL. The other CPE isolate (K. pneumoniae) is a VIM-1 producer. VIM-1-producing K. pneumoniae is epidemic in Europe, especially in Greece. Accordingly, the VIM-1 producer was isolated from a patient with a medical history in Greece. Conclusions: This study revealed the emergence of E. cloacae complex co-producing IMP-1-type carbapenemase and CTX-M ESBL, and K. pneumoniae producing VIM-1 carbapenemase in clinical isolates in Japan. Metallo-β-lactamase was the most prevalent type of carbapenemase at Teikyo University Hospital, especially IMP-1-type carbapenemase. The detection of VIM-1-producing K. pneumoniae suggests that epidemic CPE from overseas can spread to countries with low CPE prevalence, such as Japan, highlighting the need for active surveillance.
Keywords: carbapenemase, Enterobacteriaceae, IMP-1, metallo-β-lactamase, multidrug resistance, VIM-1
1. Introduction
Carbapenem-resistant Enterobacteriaceae (CRE) are often multidrug-resistant (MDR) and pose severe problems in terms of clinical treatment and infection control. Recently, carbapenemase production has become a common mechanism of carbapenem resistance in Enterobacteriaceae, which has given rise to carbapenemase-producing Enterobacteriaceae (CPE). The limited options for the treatment of MDR CPE infections significantly increases morbidity and mortality [1].
Carbapenemase-producing organisms (CPO), including CPE, are emerging worldwide and have caused many outbreaks. As an example, carbapenem-resistant Acinetobacter baumannii caused a massive outbreak at Teikyo University Hospital in 2009 [2]. Based on experience gained during these outbreaks and in line with the updated recommendations of the National Epidemiological Surveillance of Infectious Diseases for the control and prevention of healthcare-associated infections with CRE [3], Teikyo University Hospital implemented active surveillance and rapid feedback as infection control measures. The implementation of strict CPO screening resulted in the identification of CPOs in patients, especially in those with a medical history abroad, and in the enforcement of strict infection controls to prevent other outbreaks. For instance, an NDM-5-producing Escherichia coli was isolated from a patient from Bangladesh in Japan in 2013 [4]. An NDM-1-producing Klebsiella pneumoniae was isolated in 2014 from a patient with a medical history in Indonesia [4]. In 2016, multiple carbapenemase-producing Gram-negative bacilli were isolated from a single patient with an ICU admission history in Indonesia [5]. These CPOs were colistin-resistant KPC-2-producing K. pneumoniae, IMP-7-producing Pseudomonas aeruginosa, and OXA-23-producing A. baumannii. Recently, an OXA-48-like-producing E. coli was isolated from a patient treated with percutaneous transhepatic biliary drainage in India [6].
Here, we describe the results of a survey of carbapenemases among CPE collected at Teikyo University Hospital in 2018. In addition to admission screening, we screened inpatients for the presence of CPOs. We thus identified multiple metallo-β-lactamase (MBL)-producing Enterobacteriaceae. We report here the isolation of Enterobacter cloacae complex and Klebsiella oxytoca producing IMP-1, Enterobacter cloacae complex co-producing IMP-1-type MBL, and CTX-M ESBL from patients in Japan, and K. pneumoniae producing VIM-1 MBL from another patient, who had a medical history in Greece. Current and previous studies suggest that epidemic CRE has continuously spread to countries with low CRE prevalence, such as Japan. The present study stresses the importance of active antimicrobial resistance surveillance in hospital settings.
2. Materials and Methods
2.1. Isolation and Identification
Teikyo University Hospital has 1078 beds. Carbapenem-resistant Enterobacteriaceae were collected from January to December 2018. Seventy carbapenem-resistant clinical isolates were collected from 63,712 samples during 2018. Carbapenem resistance was defined as a minimum inhibitory concentration (MIC) ≥ 2 mg/L for imipenem. Microbiological analysis was performed as previously reported [5]. Briefly, faecal samples, tracheal samples (aspirate and sputum), and pharyngeal and wound swabs were collected for screening. To screen for ESBL-producing bacteria and CPOs, the samples were plated on CHROM agar ESBL/MDRA (Kanto Chemical, Tokyo, Japan), BTB agar (Eiken Chemical, Tokyo, Japan) with a piperacillin/tazobactam (100/10 μg) disc (Becton Dickinson, Franklin Lakes, NJ, USA), and NAC agar (Eiken Chemical) with an imipenem (10 μg) disc (Becton Dickinson). Antimicrobial susceptibility testing was performed using MicroScan WalkAway (Beckman Coulter, Brea, CA, USA). Antimicrobial susceptibility of isolates was defined according to the breakpoints listed in the CLSI guidelines M100-S24 [7]. Carbapenemase production was investigated using a carbapenemase inactivation method [8]. MBL production was confirmed by a double-disk synergy test using a sodium mercaptoacetic acid disc (Eiken Chemical) [9]. The isolates were identified using a MALDI biotyper (Bruker Daltonics, Billerica, MA, USA) and VITEK MS (bioMérieux, Marcy l’Etoile, France).
2.2. Multilocus Sequence Typing (MLST)
MLST was performed using the protocol developed by the Institut Pasteur (https://bigsdb.pasteur.fr) [10] and provided by PubMLST (https://pubmlst.org) [11,12]. Genomic DNA was isolated using a DNeasy Blood & Tissue kit (Qiagen, Hilden, Germany). DNA fragments were amplified by PCR using KOD FX Neo (Toyobo, Osaka, Japan) and specific primers (Supplemental Material) in a final volume of 50 µL. The amplification began with an initial denaturation at 94 °C for 2 min followed by 35 cycles of amplification using a step program (10 s at 98 °C, 30 s at the melting temperature (Tm), and 1 min at 68 °C). The PCR products were treated with ExoSAP-IT Express (Affymetrix, Santa Clara, CA, USA) and directly sequenced as described in our previous report [2].
2.3. Resistance Gene Typing and Plasmid Replicon Typing
The Cica Geneus genotype detection kit (Kanto Chemical) was used for multiplex PCR to detect the ESBL (SHV, TEM, CTX-M-1, CTX-M-2, CTX-M-8, and CTX-M-9 groups) and carbapenemase (GES, IMP-1 group, IMP-6, KPC, NDM, OXA-48-like, and VIM) genes. Plasmid replicons were detected by PCR using KOD FX Neo (Toyobo) and specific primers (Supplemental Materials) [13]. DNA fragments containing MBL genes were amplified by PCR using KOD FX Neo (Toyobo) and specific primers (Supplemental Material) [14], treated with ExoSAP-IT Express (Affymetrix), and directly sequenced [2].
3. Results and Discussion
We collected 70 carbapenem-resistant clinical isolates during 2018. Among them, we identified four CPE as MBL-producing Enterobacteriaceae: two E. cloacae complex isolates, and Klebsiella oxytoca and K. pneumoniae isolates. CRE accounted for <0.2% of the bacterial isolations, and CPE accounted for <6% of the CRE infections, consistent with the results of a previous national surveillance report in 2014 [3]. The antimicrobial susceptibility profiles of the MBL-producing Enterobacteriaceae isolates, strain numbers, sample characteristics, MLST, carbapenemase production, and ESBL are summarised in Table 1. All the MBL-producing Enterobacteriaceae isolates were MDR.
Table 1.
Antimicrobial susceptibility profiles of metallo-β-lactamase (MBL)-producing Enterobacteriaceae.
| Patient | 1 | 2 | 3 | 4 |
|---|---|---|---|---|
| Sex | F | M | F | M |
| Age (years) | 60 | 34 | 84 | 70 |
| Date of isolation | 7/5/2018 | 25/7/2018 | 4/9/2018 | 16/12/2018 |
| Sample | Pharyngeal mucus | Faeces | Urine | Faeces |
| Species | E. cloacae | K. pneumoniae | E. cloacae | K. oxytoca |
| Strain number | TK1601 | TK1602 | TK1603 | TK1604 |
| MLST | ST252 | ST70 | ST78 | ST88 |
| Plasmid Inc | FIB, HI2 | FIB, HI1 | FIB, HI2, L/M | FIB, HI2 |
| Carbapenemase | IMP-1 | VIM-1 | IMP-10 | IMP-1 |
| ESBL | – | – | CTX-M-1 | – |
| Antimicrobial agent | MIC (mg/L) a | |||
| Penicillins | ||||
| Ampicillin | >16 | >16 | >16 | >16 |
| Piperacillin | >64 | >64 | >64 | 64 |
| Sulbactam/ampicillin | >16 | >16 | >16 | >16 |
| Amoxicillin/clavulanic acid | >16 | >16 | >16 | >16 |
| Tazobactam/piperacillin | >64 | >64 | >64 | 8 |
| Cephalosporins | ||||
| Cefazolin | >16 | >16 | >16 | >16 |
| Cefotiam | >16 | >16 | >16 | >16 |
| Cefotaxim | >2 | >2 | >2 | >2 |
| Ceftazidime | >16 | >16 | >16 | >16 |
| Ceftriaxone | >2 | >2 | >2 | >2 |
| Cefepime | >16 | 16 | >16 | 16 |
| Cefozopran | >16 | >16 | >16 | 8 |
| Cefmetazole | >32 | >32 | >32 | >32 |
| Cefaclor | >16 | >16 | >16 | >16 |
| Cefdinir | >2 | >2 | >2 | >2 |
| Cefpodoxime | >4 | >4 | >4 | >4 |
| Cefcapene | >2 | >2 | >2 | >2 |
| Flomoxef | >32 | >32 | >32 | 32 |
| Sulbactam/cephoperazon | >32 | >32 | >32 | >32 |
| Carbapenems | ||||
| Doripenem | 4 | 8 | >8 | >8 |
| Imipenem | 4 | 4 | >8 | 4 |
| Meropenem | 4 | 4 | >8 | 8 |
| Monobactam | ||||
| Aztreonam | 4 | 8 | >16 | 4 |
| Fluoroquinolones | ||||
| Ciprofloxacin | 0.25 | 0.25 | >2 | 1 |
| Levofloxacin | 0.5 | 0.5 | >4 | 2 |
| Sitafloxacin | 1 | 1 | >2 | 1 |
| Aminoglycosides | ||||
| Gentamicin | 2 | 8 | 8 | 2 |
| Tobramycin | 8 | >8 | 8 | 4 |
| Amikacin | 4 | 8 | 4 | 4 |
| Tetracycline Minocycline |
>8 | 2 | >8 | 8 |
| Polymyxin | ||||
| Colistin | NT | 2 | NT | 2 |
| Other | ||||
| Fosfomycin | 16 | >16 | >16 | 16 |
| Trimethoprim/sulfamethoxazole | 2 | >2 | >2 | 2 |
a Values in bold indicate resistant; NT, not tested.
The carbapenemase and ESBL genes harboured by the isolates were identified by multiplex PCR. Strain TK1601 harboured blaIMP-1; strain TK1602 harboured blaVIM and blaSHV; strain TK1603 harboured blaIMP-1, blaCTX-M-1, and blaTEM; and strain TK1604 harboured blaIMP-1. Sequencing analysis identified the blaVIM gene in K. pneumoniae and blaIMP-1 gene in an isolate of E. cloacae complex as blaVIM-1 and blaIMP-10, respectively.
The four Enterobacteriaceae isolates produced MBLs representing IMP-1-type and VIM-1 enzymes. IMP-1 is an epidemic MBL in Japan [15]. The distribution of IMP-producing Gram-negative bacteria in Japan is biased, such that, as reported, IMP-1 occurs more frequently in eastern Japan and IMP-6 occurs more frequently in western Japan [15,16]. The detection of IMP-1 at Teikyo University Hospital was consistent with such an IMP distribution in Japan. The detection of IMP-1-producing K. oxytoca at the University of Tokyo Hospital was previously reported in 2009 [17]. The detected strain may be similar to the one detected in the current study, as their drug sensitivity patterns, as reported, are identical (Table 2). The MLST of previous K. oxytoca was not performed. In this study, IMP-1-producing K. oxytoca and IMP-1-producing E. cloacae complex were found to belong to ST88 and ST252, respectively. E. cloacae complex ST252 was initially isolated as a KPC-3 producer from a liver-transplant patient in a hospital (PA, USA) in 2009 [18]. E. cloacae complex ST252 producing GES-5 was isolated from the leg wounds of a diabetic patient in a Czech hospital in 2016 [19]. IMP-1-producing E. cloacae ST252 and IMP-1-producing K. oxytoca ST88, such as the isolate characterised in this study, have never been reported. Therefore, IMP-1-producing E. cloacae ST252 and IMP-1-producing K. oxytoca ST88 might have emerged locally in Japan. This finding suggests that E. cloacae ST252 is an international clone of a carbapenemase reservoir, although this will require further investigation. Furthermore, in Tokyo, the in-hospital mortality of patients colonised by IMP-1-producing E. cloacae complex is high [20]. Therefore, it is necessary to continue to screen hospitalised patients for the presence of IMP-1-producing E. cloacae complex as an essential measure for infection control.
Table 2.
Antimicrobial susceptibility profiles of IMP-1-producing K. oxytoca from this study and a previous study [17].
| Strain Number | TK1604 | K27 |
|---|---|---|
| Year of isolation | 2018 | 2006 |
| MLST | ST88 | NT |
| Carbapenemase | IMP-1 | IMP-1 |
| ESBL | – | – |
| Cephalosporins | ||
| Cefazolin | >16 | >128 |
| Cefotaxim | >2 | 32 |
| Ceftazidime | >16 | >64 |
| Cefoperazone | NT | >128 |
| Sulbactam/cefoperazone | >32 | NT |
| Carbapenems | ||
| Imipenem | 4 | 2 |
| Meropenem | 8 | 4 |
| Monobactam | ||
| Aztreonam | 4 | 1 |
| Fluoroquinolones | ||
| Ciprofloxacin | 1 | 1 |
| Levofloxacin | 2 | 2 |
| Aminoglycosides | ||
| Gentamicin | 2 | 1 |
| Amikacin | 4 | 2 |
Minimum inhibitory concentration (MIC) values in bold indicate resistant; NT, not tested.
On the other hand, the current study identified an E. cloacae complex isolate co-producing IMP-10 and CTX-M-1 group enzymes. Of note, IMP-1-producing E. cloacae complex ST78 is a successful (prevalent and persistent) clone in Tokyo [15]. Interestingly, we identified IMP-10-producing E. cloacae complex ST78, suggesting a selection of an ST78 strain variant producing IMP-1 with a V49F (145 G to T) substitution [21,22]. The distribution of IMP-1 and IMP-10 enzymes was reported in other CPE species, such as Serratia marcescens in Tokyo [23]. IMP-1- and IMP-10-producing S. marcescens have Class I integrons similar to In316 located in the plasmid pMTY11043_IncHI2 harboured by IMP-1-producing E. cloacae complex ST78 isolate TUM11043 [15,23]. Therefore, plasmids carrying Class I integrons encoding IMP-1 and IMP-10 might be widely distributed in CPE in Tokyo. Because IMP-10-producing P. aeruginosa was initially reported in Japan and Class I integrons encoding IMP-10 in P. aeruginosa isolates have a similar structure to the Class 1 integron in S. marcescens, the mobile genetic element carrying blaIMP-10 might have been transferred initially from P. aeruginosa to Enterobacteriaceae in Japan [21,23,24,25]. The MBL-producing Enterobacteriaceae isolates in this study share the incompatibility plasmids IncFIB and IncHI2. The IMP-10-producing E. cloacae complex and VIM-1-producing K. pneumoniae harboured the unique incompatibility plasmids IncL/M and IncHI1, respectively.
We isolated VIM-1-producing K. pneumoniae from a patient who had been previously hospitalised in Greece. Hospitalisation in Greece might be a risk factor for infection or colonisation by VIM-producing Enterobacteriaceae. For instance, an outbreak of VIM-1-producing K. pneumoniae from Greece in a hospital in France was reported in 2006 [26]. Many VIM-producing K. pneumoniae strains are being isolated in Greece [27]. The dominant clone of VIM-1-producing K. pneumoniae belongs to ST147 [28]. K. pneumoniae ST70 was characterised as an NDM-1 producer in Greece [29]. However, a VIM-1-producing K. pneumoniae ST70, such as the isolate characterised in the current study, has never been reported. The emerging clone of K. pneumoniae ST70 may have evolved to host a mobile genetic element encoding VIM-1.
VIM-2-producing P. aeruginosa has spread throughout Asia, including Japan [30]. By contrast, the VIM-producing Enterobacteriaceae isolate from Japan was reported as a VIM-2-producing E. cloacae, isolated from a patient in a paediatric ward [31]. However, the most notorious nosocomial pathogen, K. pneumoniae, producing VIM-1 has not yet been reported in Japan. VIM-2 is a significant epidemic carbapenemase harboured by P. aeruginosa in Japan. Therefore, the possibility that the VIM-1-encoding plasmid might be transferred from P. aeruginosa to K. pneumoniae in Japan may be excluded. On the other hand, VIM-1-producing K. pneumoniae is epidemic in Europe [1].
The findings presented herein suggest that a medical history in Greece might be linked to the CPE colonisation described in this study. This should serve as a warning about the possibility that doctors and other medical staff can come into contact with CPE when admitting patients colonised by CPE, and then spread the infection to other inpatients at the hospital. To reduce the spread of CPE in low-prevalence countries, such as Japan, the screening of all patients, especially those with a history of hospitalisation and travel abroad, is inevitable.
Given the limitations imposed by this surveillance study, the carbapenemase production by CRE may have been underestimated because of the relatively short screening period and the exclusion of CPE isolates but not resistant isolates. Although we detected MBL as a major carbapenemase in a CRE at Teikyo University Hospital in 2018, it strongly depended on the yearly screened patients (Table 3). The screening methods used to identify CPE also affected the results. Nevertheless, the implementation of active surveillance has helped to prevent the spread of CPO in the last decade at Teikyo University Hospital. Improvements in the methods for screening CPE may help to more precisely reveal the status of CPE colonization or infection in healthcare settings in the future.
Table 3.
Carbapenemase-producing Gram-negative organisms isolated at Teikyo University Hospital, Tokyo, Japan.
| Organism | Carbapenemase | MLST | Year of Isolation | Clinical History Location | Other Properties | Reference |
|---|---|---|---|---|---|---|
| A. baumannii | OXA-51-like | 2009/2010 | NA | MDR, outbreak | [2] | |
| E. coli | NDM-5 | ST540 | 2013 | Bangladesh | NDM-5 in Japan | [4] |
| K. pneumoniae | NDM-1 | ST76 | 2014 | Indonesia | NDM-1 in Japan | [4] |
| K. pneumoniae | KPC-2 | ST11 | 2016 | Indonesia | PDR | [5,32] |
| P. aeruginosa | IMP-7 | ST357 | 2016 | Indonesia | XDR | [5] |
| A. baumannii | OXA-23, OXA-66 | ST1050 | 2016 | Indonesia | XDR | [5] |
| E. coli | OXA-48-like | 2018 | India | MDR | [6] | |
| K. pneumoniae | VIM-1 | ST70 | 2018 | Greece | VIM-1 in Japan | This study |
| K. oxytoca | IMP-1 | ST88 | 2018 | NA | Epidemic in Japan | This study |
| E. cloacae | IMP-1 | ST252 | 2018 | NA | Epidemic in Japan | This study |
| E. cloacae | IMP-10 | ST78 | 2018 | NA | IMP-10 in Japan | This study |
NA, not available; MDR, multidrug-resistant; PDR, pandrug-resistant; XDR, extensively drug-resistant.
In conclusion, we report here the isolation of E. cloacae complex co-producing IMP-1-type MBL and CTX-M ESBL, E. cloacae complex producing IMP-1 MBL, K. oxytoca producing IMP-1 MBL, and K. pneumoniae producing VIM-1 MBL in Japan. This study contributes to the delineation of recent epidemic trends and treatment options for CPE in Tokyo, Japan, and highlights the possibility of resistance gene transfer among Enterobacteriaceae as well as resistance gene spread from travellers returning from abroad. The study also highlights the need for active surveillance and analysis of the medical history of patients returning from travel abroad.
Acknowledgments
We thank Ubagai, Nagakawa, Ueda, and Sato from the Department of Microbiology and Immunology at Teikyo University School of Medicine for helpful discussions and technical assistance.
Supplementary Materials
The following are available online at https://www.mdpi.com/2076-2607/8/11/1816/s1.
Author Contributions
N.M. and Y.K. designed the study. The experiments were conducted by S.N. and Y.K. and supervised by S.I., T.F., and Y.O. S.N., N.M., and Y.K. performed data analysis, and S.N. wrote the manuscript. S.N., N.M., and Y.O. reviewed and edited the manuscript. All authors have read and agreed to the published version of the manuscript.
Funding
This work was supported by the Japan Society for the Promotion of Science (KAKENHI 17K10032 to YO, KAKENHI 18K10030 to SN) and the Ministry of Education, Culture, Sports, Science and Technology (MEXT) (Private University Research Branding Project).
Conflicts of Interest
The authors declare no conflict of interest.
Footnotes
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.Tzouvelekis L.S., Markogiannakis A., Psichogiou M., Tassios P.T., Daikos G.L. Carbapenemases in Klebsiella pneumoniae and other Enterobacteriaceae: An Evolving Crisis of Global Dimensions. Clin. Microbiol. Rev. 2012;25:682–707. doi: 10.1128/CMR.05035-11. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Nishida S., Ono Y. Comparative analysis of the pathogenicity between multidrug-resistant Acinetobacter baumannii clinical isolates: Isolation of highly pathogenic multidrug-resistant A. baumannii and experimental therapeutics with fourth-generation cephalosporin cefozopran. Infect. Drug Resist. 2018;11:1715–1722. doi: 10.2147/IDR.S166154. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Infectious Disease Surveillance Center, National Institute of Infectious Diseases Carbapenem-resistant Enterobacteriaceae Infection, Japan. Infect Agents Surveill. Rep. 2014;35:281–282. [Google Scholar]
- 4.Nakano R., Nakano A., Hikosaka K., Kawakami S., Matsunaga N., Asahara M., Ishigaki S., Furukawa T., Suzuki M., Shibayama K., et al. First Report of Metallo-β-Lactamase NDM-5-Producing Escherichia coli in Japan. Antimicrob. Agents Chemother. 2014;58:7611–7612. doi: 10.1128/AAC.04265-14. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Nishida S., Ishigaki S., Asahara M., Furukawa T., Ono Y. Emergence of multiple carbapenemase-producing Gram-negative species, colistin-resistant KPC-2-producing Klebsiella pneumoniae ST11, IMP-7-producing Pseudomonas aeruginosa ST357, and OXA-23-producing Acinetobacter baumannii ST1050, in a single patient. Int. J. Antimicrob. Agents. 2018;52:512–514. doi: 10.1016/j.ijantimicag.2018.06.022. [DOI] [PubMed] [Google Scholar]
- 6.Nishida S., Asahara M., Nemoto K., Ishigaki S., Furukawa T., Sano K., Ono Y. Emergence of Escherichia coli producing OXA-48-like carbapenemase in a patient with percutaneous transhepatic biliary drainage. Infect. Prev. Pr. 2019;1:100008. doi: 10.1016/j.infpip.2019.100008. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Clinical and Laboratory Standards Institute . Performance Standards for Antimicrobial Susceptibility Testing. Nat’l Comm Clinical LAB Standards; Wayne, PA, USA: 2014. Twenty-Fourth Informational Supplement; CLSI document M100-S24. [Google Scholar]
- 8.van der Zwaluw K., de Haan A., Pluister G.N., Bootsma H.J., de Neeling A.J., Schouls L.M. The Carbapenem Inactivation Method (CIM), a Simple and Low-Cost Alternative for the Carba NP Test to Assess Phenotypic Carbapenemase Activity in Gram-Negative Rods. PLoS ONE. 2015;10:e0123690. doi: 10.1371/journal.pone.0123690. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Arakawa Y., Shibata N., Shibayama K., Kurokawa H., Yagi T., Fujiwara H., Goto M. Convenient Test for Screening Metallo-β-Lactamase-Producing Gram-Negative Bacteria by Using Thiol Compounds. J. Clin. Microbiol. 2000;38:40–43. doi: 10.1128/jcm.38.1.40-43.2000. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Brisse S., Fevre C., Passet V., Issenhuth-Jeanjean S., Tournebize R., Diancourt L., Grimont P. Virulent Clones of Klebsiella pneumoniae: Identification and Evolutionary Scenario Based on Genomic and Phenotypic Characterization. PLoS ONE. 2009;4:e4982. doi: 10.1371/journal.pone.0004982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Miyoshi-Akiyama T., Hayakawa K., Ohmagari N., Shimojima M., Kirikae T. Multilocus Sequence Typing (MLST) for Characterization of Enterobacter cloacae. PLoS ONE. 2013;8:e66358. doi: 10.1371/journal.pone.0066358. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Jolley K.A., Bray J.E., Maiden M.C.J. Open-access bacterial population genomics: BIGSdb software, the PubMLST.org website and their applications. Wellcome Open Res. 2018;3:124. doi: 10.12688/wellcomeopenres.14826.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Carattoli A., Bertini A., Villa L., Falbo V., Hopkins K.L., Threlfall E.J. Identification of plasmids by PCR-based replicon typing. J. Microbiol. Methods. 2005;63:219–228. doi: 10.1016/j.mimet.2005.03.018. [DOI] [PubMed] [Google Scholar]
- 14.Yan J.-J., Hsueh P.-R., Ko W.-C., Luh K.-T., Tsai S.-H., Wu H.-M., Wu J.-J. Metallo-β-Lactamases in Clinical Pseudomonas Isolates in Taiwan and Identification of VIM-3, a Novel Variant of the VIM-2 Enzyme. Antimicrob. Agents Chemother. 2001;45:2224–2228. doi: 10.1128/AAC.45.8.2224-2228.2001. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Aoki K., Harada S., Yahara K., Ishii Y., Motooka D., Nakamura S., Akeda Y., Iida T., Tomono K., Iwata S., et al. Molecular Characterization of IMP-1-Producing Enterobacter cloacae Complex Isolates in Tokyo. Antimicrob. Agents Chemother. 2018;62:e02091-17. doi: 10.1128/AAC.02091-17. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Yano H., Ogawa M., Endo S., Kakuta R., Kanamori H., Inomata S., Ishibashi N., Aoyagi T., Hatta M., Gu Y., et al. High Frequency of IMP-6 among Clinical Isolates of Metallo-β-Lactamase-Producing Escherichia coli in Japan. Antimicrob. Agents Chemother. 2012;56:4554–4555. doi: 10.1128/AAC.00617-12. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Ode T., Saito R., Kumita W., Sato K., Okugawa S., Moriya K., Koike K., Okamura N. Analysis of plasmid-mediated multidrug resistance in Escherichia coli and Klebsiella oxytoca isolates from clinical specimens in Japan. Int. J. Antimicrob. Agents. 2009;34:347–350. doi: 10.1016/j.ijantimicag.2009.05.007. [DOI] [PubMed] [Google Scholar]
- 18.Ahn C., Syed A., Hu F., O’Hara J.A., Rivera J.I., Doi Y. Microbiological features of KPC-producing Enterobacter isolates identified in a U.S. hospital system. Diagn. Microbiol. Infect. Dis. 2014;80:154–158. doi: 10.1016/j.diagmicrobio.2014.06.010. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Chudejova K., Rotova V., Skalova A., Medvecky M., Adámková V., Papagiannitsis C.C., Hrabak J. Emergence of sequence type 252 Enterobacter cloacae producing GES-5 carbapenemase in a Czech hospital. Diagn. Microbiol. Infect. Dis. 2018;90:148–150. doi: 10.1016/j.diagmicrobio.2017.10.011. [DOI] [PubMed] [Google Scholar]
- 20.Hayakawa K., Miyoshi-Akiyama T., Kirikae T., Nagamatsu M., Shimada K., Mezaki K., Sugiki Y., Kuroda E., Kubota S., Takeshita N., et al. Molecular and Epidemiological Characterization of IMP-Type Metallo-β-Lactamase-Producing Enterobacter cloacae in a Large Tertiary Care Hospital in Japan. Antimicrob. Agents Chemother. 2014;58:3441–3450. doi: 10.1128/AAC.02652-13. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Iyobe S., Kusadokoro H., Takahashi A., Yomoda S., Okubo T., Nakamura A., O’Hara K. Detection of a Variant Metallo-β-Lactamase, IMP-10, from Two Unrelated Strains of Pseudomonas aeruginosa and an Alcaligenes xylosoxidans Strain. Antimicrob. Agents Chemother. 2002;46:2014–2016. doi: 10.1128/AAC.46.6.2014-2016.2002. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.LaCuran A.E., Pegg K.M., Liu E.M., Bethel C.R., Ai N., Welsh W.J., Bonomo R.A., Oelschlaeger P. Elucidating the Role of Residue 67 in IMP-Type Metallo-β-Lactamase Evolution. Antimicrob. Agents Chemother. 2015;59:7299–7307. doi: 10.1128/AAC.01651-15. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Hu Z., Zhao W.-H. Identification of plasmid- and integron-borne blaIMP-1 and blaIMP-10 in clinical isolates of Serratia marcescens. J. Med. Microbiol. 2009;58:217–221. doi: 10.1099/jmm.0.006874-0. [DOI] [PubMed] [Google Scholar]
- 24.Takeda S., Nakai T., Ikeda F., Hatano K. Overproduction of a Metallo-β-Lactamase by a Strong Promoter Causes High-Level Imipenem Resistance in a Clinical Isolate of Pseudomonas aeruginosa. Chemotherapy. 2008;54:181–187. doi: 10.1159/000140362. [DOI] [PubMed] [Google Scholar]
- 25.Zhao W.-H., Chen G., Ito R., Hu Z.-Q. Relevance of resistance levels to carbapenems and integron-borne blaIMP-1, blaIMP-7, blaIMP-10 and blaVIM-2 in clinical isolates of Pseudomonas aeruginosa. J. Med Microbiol. 2009;58:1080–1085. doi: 10.1099/jmm.0.010017-0. [DOI] [PubMed] [Google Scholar]
- 26.Kassis-Chikhani N., Decré D., Gautier V., Burghoffer B., Saliba F., Mathieu D., Samuel D., Castaing D., Petit J.-C., Dussaix E., et al. First outbreak of multidrug-resistant Klebsiella pneumoniae carrying blaVIM-1 and blaSHV-5 in a French university hospital. J. Antimicrob. Chemother. 2005;57:142–145. doi: 10.1093/jac/dki389. [DOI] [PubMed] [Google Scholar]
- 27.Vatopoulos A. High rates of metallo-β-lactamase-producing Klebsiella pneumoniae in Greece—A review of the current evidence. Euro Surveill. 2008;13:8023. doi: 10.2807/ese.13.04.08023-en. [DOI] [PubMed] [Google Scholar]
- 28.Matsumura Y., Peirano G., DeVinney R., Bradford P.A., Motyl M.R., Adams M.D., Chen L., Kreiswirth B., Pitout J.D.D. Genomic epidemiology of global VIM-producing Enterobacteriaceae. J. Antimicrob. Chemother. 2017;72:2249–2258. doi: 10.1093/jac/dkx148. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Politi L., Gartzonika K., Spanakis N., Zarkotou O., Poulou A., Skoura L., Vrioni G., Tsakris A. Emergence of NDM-1-producing Klebsiella pneumoniae in Greece: Evidence of a widespread clonal outbreak. J. Antimicrob. Chemother. 2019;74:2197–2202. doi: 10.1093/jac/dkz176. [DOI] [PubMed] [Google Scholar]
- 30.Hong D.J., Bae I.K., Jang I.-H., Jeong S.H., Kang H.K., Lee K.-W. Epidemiology and Characteristics of Metallo-β-Lactamase-Producing Pseudomonas aeruginosa. Infect. Chemother. 2015;47:81–97. doi: 10.3947/ic.2015.47.2.81. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31.Nishio H., Komatsu M., Shibata N., Shimakawa K., Sueyoshi N., Ura T., Satoh K., Toyokawa M., Nakamura T., Wada Y., et al. Metallo-β-Lactamase-Producing Gram-Negative Bacilli: Laboratory-Based Surveillance in Cooperation with 13 Clinical Laboratories in the Kinki Region of Japan. J. Clin. Microbiol. 2004;42:5256–5263. doi: 10.1128/JCM.42.11.5256-5263.2004. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32.Nishida S., Ono Y. Genomic analysis of a pan-resistant Klebsiella pneumoniae sequence type 11 identified in Japan in 2016. Int. J. Antimicrob. Agents. 2020;55:105854. doi: 10.1016/j.ijantimicag.2019.11.011. [DOI] [PubMed] [Google Scholar]
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