Ann Lab Med 2022; 42(1): 36-46
Published online January 1, 2022 https://doi.org/10.3343/alm.2022.42.1.36
Copyright © Korean Society for Laboratory Medicine.
Genotypic Distribution and Antimicrobial Susceptibilities of Carbapenemase-Producing Enterobacteriaceae Isolated From Rectal and Clinical Samples in Korean University Hospitals Between 2016 and 2019
1Department of Laboratory Medicine, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea; 2Department of Laboratory Medicine, Hangang Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea; 3Department of Laboratory Medicine, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea; 4Department of Laboratory Medicine, Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Korea; 5Department of Laboratory Medicine, Kangdong Sacred Heart Hospital, Seoul, Korea
Correspondence to: Wonkeun Song, M.D., Ph.D.
Department of Laboratory Medicine, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, 1 Shingil-ro, Youngdeungpo-gu, Seoul 07441, Korea
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background: The emergence of carbapenemase-producing Enterobacteriaceae (CPE) represents a major clinical problem. Recently, the occurrence of CPE has increased globally, but epidemiological patterns vary across region. We report the trends in the genotypic distribution and antimicrobial susceptibility of CPE isolated from rectal and clinical samples during a four-year period.
Methods: Between January 2016 and December 2019, 1,254 nonduplicated CPE isolates were obtained from four university hospitals in Korea. Carbapenemase genotypes were determined by multiplex real-time PCR. Antimicrobial susceptibility was profiled using the Vitek 2 system (bioMérieux, Hazelwood, MO, USA) or MicroScan Walkaway-96 system (Siemens West Sacramento, CA, USA). The proportions of carbapenemase genotypes and nonsusceptibility were analyzed using Pearson’s chi-square test.
Results: Among the 1,254 CPE isolates, 486 (38.8%), 371 (29.6%), 357 (28.5%), 8 (0.6%), 8 (0.6%), and 24 (1.9%) were Klebsiella pneumoniae carbapenemase (KPC), oxacillinase (OXA)-48-like, New Delhi metallo-β-lactamase (NDM), imipenemase (IMP), Verona integron-encoded metallo-β-lactamase (VIM), and multiple producers, respectively. The predominant species was K. pneumoniae (72.6%), followed by Escherichia coli (6.5%). More than 90% of the isolates harboring KPC, NDM, and OXA-48-like were nonsusceptible to cephalosporins, aztreonam, and carbapenems.
Conclusions: The impact of CPE is primarily due to KPC-, NDM-, and OXA-48-like-producing K. pneumoniae isolates. Isolates carrying these carbapenemase are mostly multidrug-resistant. Control strategies based on these genotypic distributions and antimicrobial susceptibilities of CPE isolates are required.
Keywords: Carbapenemase-producing Enterobacteriaceae, Klebsiella pneumoniae, Klebsiella pneumoniae carbapenemase, New Delhi metallo-β-lactamase, oxacillinase-48-like
The emergence of carbapenemase-producing
The occurrence of CPE has increased globally, but their epidemiological patterns vary across region. KPC-producing
Multicenter studies on the prevalence and molecular epidemiology or antimicrobial susceptibilities of CPE have been conducted in Korea [9, 10]. Reporting the recent status of genotypic distribution of CPE in relation to antimicrobial susceptibilities based on a multicenter study is necessary to increase the awareness about and control of these isolates. We report the genotypic distribution and antimicrobial susceptibilities of CPE isolated from rectal and clinical samples in four Korean university hospitals during a 4-year period.
MATERIALS AND METHODS
Study design and CPE isolate identification
Between January 2016 and December 2019, CPE isolates were prospectively collected from four university hospitals in a metropolitan area of Korea (two hospitals, Kangnam Sacred Heart Hospital with 572 beds [A] and Hangang Sacred Heart Hospital with 158 beds [B] in Seoul, and two, Hallym University Sacred Heart Hospital with 834 beds [C] and Dongtan Sacred Heart Hospital with 660 beds [D] in Gyeonggi-do). In total, 1,254 nonduplicated CPE isolates harboring carbapenemase genes were collected (N=308, hospital A; N=55, hospital B; N=856, hospital C; N=35, hospital D). The isolates had been obtained from rectal samples taken for epidemiological and infection control purposes and clinical samples taken during the work-up of patients with suspected infections. The following clinical samples were provided: sputum (N=158, 12.6%), urine (N=130, 10.3%), blood (N=58, 4.6%), body fluid (N=36, 2.9%), wound or pus (N=22, 1.8%), and swabs (N=10, 0.8%). The isolates from patients in the intensive care unit (ICU) were more than a half of the included CPE isolates (N=792, 63.2%). Bacteria were identified using a Vitek 2 system (bioMérieux, Hazelwood, MO, USA) at hospitals B and D, amatrix-assisted laser desorption ionization-time-of-flight mass spectrometry on a Vitek-MS instrument (bioMérieux) at hospital A, and a MicroScan Walkaway-96 system (Siemens, West Sacramento, CA, USA) at hospital C. After collecting carbapenem-nonsusceptible
Genotypic detection of carbapenemase genes
PANA Real Typer CRE kits (PANAGENE Inc., Daejeon, Korea) utilizing peptide nucleic acid-mediated multiplex real-time PCR were used to type all CPE isolates that tested carbapenemase-positive using MHT and CIT. The primers and probes, which were designed to target six carbapenemase genes (
Antimicrobial susceptibility testing
The MICs of the isolates were determined using the Vitek 2 system at hospitals A, B, and D and the MicroScan Walkaway-96 system at hospital C. Nonsusceptibility rates were calculated by dividing the number of isolates showing nonsusceptibility by the total number of isolates. The analyzed antimicrobial agents were cefotaxime, ceftazidime, cefepime, aztreonam, ertapenem, imipenem (or meropenem), amikacin, gentamicin, ciprofloxacin (or levofloxacin), trimethoprim-sulfamethoxazole, and tigecycline. MIC breakpoints were applied according to the Clinical and Laboratory Standards Institute (CLSI) guidelines (M100S) . For tigecycline, MIC results were interpreted according to the European Committee for Antimicrobial Susceptibility Testing criteria . Intermediate susceptibility was determined according to the criteria set in the CLSI guidelines and per the European Committee for Antimicrobial Susceptibility Testing [13, 14].
Statistical analyses were performed using PASW version 18.0 (SPSS Inc., Chicago, IL, USA), Analyse-it Method Evaluation Edition software (version 2.26; Analyse-it Software Ltd., Leeds, UK), and R statistical software (version 3.6.3; R Foundation for Statistical Computing, Vienna, Austria). Categorical variables were compared using Pearson’s chi-square test or Fisher’s exact test. All tests were two-sided, and differences with
Distribution of CPE isolates
The CPE isolates comprised 910
The distribution of carbapenemase genes identified among the CPE isolates is illustrated in Fig. 1A. Among the 1,254 CPE isolates, 486 (38.8%), 371 (29.6%), 357 (28.5%), 8 (0.6%), 8 (0.6%), and 24 (1.9%) were KPC, OXA-48-like, NDM, IMP, VIM, and multiple producers harboring more than two types of genes, respectively. Twenty-four CPE (1.9%) isolates harbored more than two carbapenemase genes, and most of these isolates (N=19, 1.5%) contained both
Figure 1. Distributions of genotypes and patients according to the hospital. (A) Carbapenemase genotypes and (B) patients with carbapenemase-producing
Enterobacteriaceaeisolates according to year and sample type.
Abbreviations: A, Kangnam Sacred Heart Hospital; B, Hangang Sacred Heart Hospital; C, Hallym University Sacred Heart Hospital; D, Dongtan Sacred Heart Hospital; KPC,
K. pneumoniaecarbapenemase; NDM, New Delhi metallo-β-lactamase; OXA-48, oxacillinase-48; IMP, imipenemase; VIM, Verona integron-encoded metallo-β-lactamase.
The distribution of carbapenemase genotypes according to species is presented in Table 1. The most prevalent species among the KPC, NDM, and OXA-48-like producers was
Antimicrobial susceptibility profile
More than 90% of
Figure 2. Antimicrobial susceptibility profiles of
Enterobacteriaceaeisolates producing (A) KPC, (B) NDM, and (C) OXA-48-like.
Abbreviations: CTX, cefotaxime; CAZ, ceftazidime; FEP, cefepime; ATM, aztreonam; EPM, ertapenem; IMP/MPM, imipenem (or meropenem); AMK, amikacin; GEN, gentamicin; CIP/LEV, ciprofloxacin (or levofloxacin); T-S, trimethoprim-sulfamethoxazole; TIG, tigecycline; KPN,
K. pneumoniae; KPC, K. pneumoniaecarbapenemase; NDM, New Delhi metallo-β-lactamase; OXA-48, oxacillinase-48.
Figure 3. Antimicrobial susceptibility profiles of
K. pneumoniaeisolates producing (A) KPC, (B) NDM, and (C) OXA-48-like by sample types.
Abbreviations: CTX, cefotaxime; CAZ, ceftazidime; FEP, cefepime; ATM, aztreonam; EPM, ertapenem; IMP/MPM, imipenem (or meropenem); AMK, amikacin; GEN, gentamicin; CIP/LEV, ciprofloxacin (or levofloxacin); T-S, trimethoprim-sulfamethoxazole; TIG, tigecycline; KPC,
K. pneumoniaecarbapenemase; NDM, New Delhi metallo-β-lactamase; OXA-48, oxacillinase-48.
Increasing trends in CPE prevalence and spread have been identified worldwide [7, 15]. Concordant with previous studies, we mainly identified KPC (38.8%), OXA-48-like (29.6%), and NDM (28.5%) producers [9, 16]. The predominantly isolated species (
In the USA and Europe,
The Indian subcontinent is recognized as an NDM endemic zone, and the associated species are mostly
OXA-48-like producers are often detected in Northern Africa and the Mediterranean area and is increasingly being reported in
Although the proportions of IMP (0.6%) and VIM (0.6%) producers among CPE were relatively low in this study, strains with these genes cause sporadic outbreaks mainly in Southeast Asia and the Americas, respectively . In Korea, an outbreak of IMP-producing carbapenem-nonsusceptible
The predominant CPE genotypes in Korea showed hospital-specific differences. In particular, hospital C had more NDM and OXA-48-like producers than KPC compared with the other hospitals. Thus, the control of nosocomial spread of CPE may require different measures depending on the local circumstances.
In line with our results, NDM-producing
In general, OXA-48-like producers effectively hydrolyze penicillins, whereas they weakly hydrolyze carbapenems and cephalosporins . Non-
This study has some limitations. We only evaluated carbapenemases, not ESBLs and AmpCs. However, most CPE isolated in Korea also harbor an ESBL . Differences in the commercial platforms utilized for the identification and antimicrobial susceptibility testing in the different hospitals might have affected the results. In addition, hospital size likely influenced the distribution results.
In summary, the impact of CPE in Korea is primarily due to KPC-, NDM-, and OXA-48-like-producing
The authors appreciate the support and cooperation of clinical microbiology technicians in Hallym University Medical Centers.
Song W designed the study; Jeong S and Lee N analyzed the data and wrote the manuscript; and Kim HS, Kim HS, Park MJ, and Kim JS edited the manuscript. All authors reviewed and approved the manuscript.
CONFLICTS OF INTEREST
This work was supported by a National Research Foundation of Korea (NRF) grant, funded by the Korean Government (Ministry of Science and ICT) (NRF-2017R1C1B2004597). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.
- Doi Y and Paterson DL. Carbapenemase-producing
Enterobacteriaceae. Semin Respir Crit Care Med 2015;36:74-84.
- Nordmann P. Carbapenemase-producing Enterobacteriaceae: overview of a major public health challenge. Med Mal Infect 2014;44:51-6.
- Walsh C. Molecular mechanisms that confer antibacterial drug resistance. Nature 2000;406:775-81.
- Lee M and Choi TJ. Antimicrobial resistance caused by KPC-2 encoded by promiscuous plasmids of the
Klebsiella pneumoniaeST307 strain. Ann Lab Med 2021;41:86-94.
- Yigit H, Queenan AM, Anderson GJ, Domenech-Sanchez A, Biddle JW, Steward CD, et al. Novel carbapenem-hydrolyzing beta-lactamase, KPC-1, from a carbapenem-resistant strain of
Klebsiella pneumoniae. Antimicrob Agents Chemother 2001;45:1151-61.
- Yong D, Toleman MA, Giske CG, Cho HS, Sundman K, Lee K, et al. Characterization of a new metallo-beta-lactamase gene,
bla(NDM-1), and a novel erythromycin esterase gene carried on a unique genetic structure in Klebsiella pneumoniaesequence type 14 from India. Antimicrob Agents Chemother 2009;53:5046-54.
- Nordmann P, Naas T, Poirel L. Global spread of carbapenemase-producing
Enterobacteriaceae. Emerg Infect Dis 2011;17:1791-8.
- Poirel L, Héritier C, Tolün V, Nordmann P. Emergence of oxacillinase-mediated resistance to imipenem in
Klebsiella pneumoniae. Antimicrob Agents Chemother 2004;48:15-22.
- Jeong SH, Kim HS, Kim JS, Shin DH, Kim HS, Park MJ, et al. Prevalence and molecular characteristics of carbapenemase-producing
Enterobacteriaceaefrom five hospitals in Korea. Ann Lab Med 2016;36:529-35.
- Lee H, Yoon EJ, Kim D, Jeong SH, Won EJ, Shin JH, et al. Antimicrobial resistance of major clinical pathogens in South Korea, May 2016 to April 2017: first one-year report from Kor-GLASS. Euro Surveill 2018;23:1800047.
- Song W, Hong SG, Yong D, Jeong SH, Kim HS, Kim HS, et al. Combined use of the modified Hodge test and carbapenemase inhibition test for detection of carbapenemase-producing
Enterobacteriaceaeand metallo-beta-lactamase-producing Pseudomonasspp. Ann Lab Med 2015;35:212-9.
- Jeong S, Kim JO, Jeong SH, Bae IK, Song W. Evaluation of peptide nucleic acid-mediated multiplex real-time PCR kits for rapid detection of carbapenemase genes in gram-negative clinical isolates. J Microbiol Methods 2015;113:4-9.
- CLSI. Performance standards for antimicrobial susceptibility testing. 27th ed. Wayne, PA: Clinical and Laboratory Standards Institute, 2016.
- European Committee on Antimicrobial Susceptibility Testing. Clinical breakpoints - breakpoints and guidance. http://www.eucast.org/clinical_breakpoints (Updated on Jan 2021).
- Song W, Park MJ, Jeong S, Shin DH, Kim JS, Kim HS, et al. Rapid identification of OXA-48-like, KPC, NDM, and VIM carbapenemase-producing
Enterobacteriaceaefrom culture: evaluation of the RESIST-4 O.K.N.V. multiplex lateral flow assay. Ann Lab Med 2020;40:259-63.
- Nordmann P and Poirel L. The difficult-to-control spread of carbapenemase producers among
Enterobacteriaceaeworldwide. Clin Microbiol Infect 2014;20:821-30.
- Rhee JY, Park YK, Shin JY, Choi JY, Lee MY, Peck KR, et al. KPC-producing extreme drug-resistant
Klebsiella pneumoniaeisolate from a patient with diabetes mellitus and chronic renal failure on hemodialysis in South Korea. Antimicrob Agents Chemother 2010;54:2278-9.
- Hong SK, Yong D, Kim K, Hong SS, Hong SG, Khosbayar T, et al. First outbreak of KPC-2-producing
Klebsiella pneumoniaesequence type 258 in a hospital in South Korea. J Clin Microbiol 2013;51:3877-9.
- Kim MN, Yong D, An D, Chung HS, Woo JH, Lee K, et al. Nosocomial clustering of NDM-1-producing
Klebsiella pneumoniaesequence type 340 strains in four patients at a South Korean tertiary care hospital. J Clin Microbiol 2012;50:1433-6.
- Yoo JS, Kim HM, Koo HS, Yang JW, Yoo JI, Kim HS, et al. Nosocomial transmission of NDM-1-producing
Escherichia coliST101 in a Korean hospital. J Antimicrob Chemother 2013;68:2170-2.
- Sekirov I, Croxen MA, Ng C, Azana R, Chang Y, Mataseje L, et al. Epidemiologic and genotypic review of carbapenemase-producing organisms in British Columbia, Canada, between 2008 and 2014. J Clin Microbiol 2016;54:317-27.
- Jeong SH, Lee KM, Lee J, Bae IK, Kim JS, Kim HS, et al. Clonal and horizontal spread of the
blaOXA-232 gene among Enterobacteriaceaein a Korean hospital. Diagn Microbiol Infect Dis 2015;82:70-2.
- Poirel L, Potron A, Nordmann P. OXA-48-like carbapenemases: the phantom menace. J Antimicrob Chemother 2012;67:1597-606.
- Walsh TR. Emerging carbapenemases: a global perspective. Int J Antimicrob Agents 2010;36:S8-14.
- Lee JY, Park JY, Kim JH, Lee YH, Yang HY, Yoo JS. Outbreak of imipenemase-1-producing carbapenem-resistant
Klebsiella pneumoniaein an intensive care unit. Korean J Crit Care Med 2017;32:29-38.
- Lauretti L, Riccio ML, Mazzariol A, Cornaglia G, Amicosante G, Fontana R, et al. Cloning and characterization of
blaVIM, a new integron-borne metallo-beta-lactamase gene from a Pseudomonas aeruginosaclinical isolate. Antimicrob Agents Chemother 1999;43:1584-90.
- Hong DJ, Bae IK, Jang IH, Jeong SH, Kang HK, Lee K. Epidemiology and characteristics of metallo-beta-lactamase-producing
Pseudomonas aeruginosa. Infect Chemother 2015;47:81-97.
- Tseng IL, Liu YM, Wang SJ, Yeh HY, Hsieh CL, Lu HL, et al. Emergence of carbapenemase producing
Klebsiella pneumoniaand spread of KPC-2 and KPC-17 in Taiwan: A nationwide study from 2011 to 2013. PLoS One 2015;10:e0138471.
- Endimiani A, Perez F, Bonomo RA. Cefepime: a reappraisal in an era of increasing antimicrobial resistance. Expert Rev Anti Infect Ther 2008;6:805-24.
- Sader HS, Fritsche TR, Jones RN. Potency and spectrum trends for cefepime tested against 65746 clinical bacterial isolates collected in North American medical centers: results from the SENTRY Antimicrobial Surveillance Program (1998-2003). Diagn Microbiol Infect Dis 2005;52:265-73.
- Ji S, Lv F, Du X, Wei Z, Fu Y, Mu X, et al. Cefepime combined with amoxicillin/clavulanic acid: a new choice for the KPC-producing
K. pneumoniaeinfection. Int J Infect Dis 2015;38:108-14.
- Bartolini A, Basso M, Franchin E, Menegotto N, Ferrari A, De Canale E, et al. Prevalence, molecular epidemiology and intra-hospital acquisition of
Klebsiella pneumoniaestrains producing carbapenemases in an Italian teaching hospital from January 2015 to September 2016. Int J Infect Dis 2017;59:103-9.
- Fuster B, Tormo N, Salvador C, Gimeno C. Detection of two simultaneous outbreaks of
Klebsiella pneumoniaecoproducing OXA-48 and NDM-1 carbapenemases in a tertiary-care hospital in Valencia, Spain. New Microbes New Infect 2020;34:100660.