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Yang P, Li J, Lv M, He P, Song G, Shan B, Yang X. Molecular Epidemiology and Horizontal Transfer Mechanism of optrA-Carrying Linezolid-Resistant Enterococcus faecalis. Pol J Microbiol 2024; 73:349-362. [PMID: 39268957 PMCID: PMC11395433 DOI: 10.33073/pjm-2024-031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 07/06/2024] [Indexed: 09/15/2024] Open
Abstract
The aim of this work was to provide a theoretical and scientific basis for the treatment, prevention, and control of clinical drug-resistant bacterial infections by studying the molecular epidemiology and horizontal transfer mechanism of optrA-carrying linezolid-resistant Enterococcus faecalis strains (LREfs) that were clinically isolated in a tertiary hospital in Kunming, China. Non-repetitive LREfs retained in a tertiary A hospital in Kunming, China. The strains were identified by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The transferability and horizontal transfer mechanism of optrA gene were analyzed using polymerase chain reaction (PCR), whole-genome sequencing (WGS), and conjugation experiments. A total of 39 LREfs strains were collected, and all of them were multi-drug resistant. There were 30 LREfs strains (76.9%) carrying the optrA gene, The cfr, poxtA genes and mutations in the 23S rRNA gene were not detected. The conjugation experiments showed that only three of 10 randomly selected optrA-carrying LREfs were successfully conjugated with JH2-2. Further analysis of one successfully conjugated strain revealed that the optrA gene, located in the donor bacterium, formed the IS1216E-erm(A)-optrA-fexA-IS1216E transferable fragment under the mediation of the mobile genetic element (MGE) IS1216E, which was then transferred to the recipient bacterium via horizontal plasmid transfer. Carrying the optrA gene is the primary resistance mechanism of LREfs strains. The optrA gene could carry the erm(A) and fexA genes to co-transfer among E. faecalis. MGEs such as insertion sequence IS1216E play an important role in the horizontal transfer of the optrA gene.
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Affiliation(s)
- Peini Yang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Jiang Li
- Department of Blood Transfusion, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Mei Lv
- Department of Clinical Laboratory, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Pingan He
- Department of Clinical Laboratory, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Guibo Song
- Department of Clinical Laboratory, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Bin Shan
- Department of Clinical Laboratory, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Xu Yang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
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Pan P, Sun L, Shi X, Huang X, Yin Y, Pan B, Hu L, Shen Q. Analysis of molecular epidemiological characteristics and antimicrobial susceptibility of vancomycin-resistant and linezolid-resistant Enterococcus in China. BMC Med Genomics 2024; 17:174. [PMID: 38951840 PMCID: PMC11218351 DOI: 10.1186/s12920-024-01948-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 06/21/2024] [Indexed: 07/03/2024] Open
Abstract
BACKGROUND This study investigates the distribution and characteristics of linezolid and vancomycin susceptibilities among Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium) and explores the underlying resistance mechanisms. METHODS A total of 2842 Enterococcus clinical isolates from patients were retrospectively collected, and their clinical data were further analyzed. The minimum inhibitory concentrations (MICs) of vancomycin and linezolid were validated by broth dilution method. The resistance genes optrA, cfr, vanA, vanB and vanM were investigated using polymerase chain reaction (PCR). Housekeeping genes and resistance genes were obtianed through whole-genome sequencing (WGS). RESULTS Of the 2842 Enterococcus isolates, 88.5% (2516) originated from urine, with E. faecium accounted for 60.1% of these. The vanA gene was identified in 27/28 vancomycin resistant Enterococcus (VRE) isolates, 4 of which carried both vanA and vanM genes. The remaining strain was vanM positive. The optrA gene was identified in all E. faecalis isolates among linezolid resistant Enterococcus (LRE). E. faecium showed a higher multiple antibiotic resistance index (MAR index) compared to E. faecalis. The multi-locus sequence typing (MLST) showed the sequence type of E. faecium mainly belongs to clonal complex (CC) 17, nearly E. faecalis isolates analyzed were differentiated into 7 characteristics of sequence types (STs), among which ST16 of CC16 were the major lineage. CONCLUSION Urine was the primary source of VRE and LRE isolates in this study. E. faecium showed higher levels of resistance compared to E. faecalis. OptrA gene was detected in 91.6% of LRE, which could explain linezolid resistance, and van genes were detected in all vancomycin resistant Enterococcus strains, while vanA was a key resistance mechanism in VRE identified in this study.
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Affiliation(s)
- Ping Pan
- Department of Clinical Laboratory, Hangzhou Women's Hospital (Hangzhou Matenal and Child Health Care Hospital), Hangzhou, Zhejiang, 310000, China
| | - Long Sun
- Department of Clinical Laboratory, Hangzhou Women's Hospital (Hangzhou Matenal and Child Health Care Hospital), Hangzhou, Zhejiang, 310000, China
| | - Xinyan Shi
- Department of Clinical Laboratory, Hangzhou Women's Hospital (Hangzhou Matenal and Child Health Care Hospital), Hangzhou, Zhejiang, 310000, China
| | - Xian Huang
- Respiratory department, Zhejiang Provincial General Hospital of Chinese People's Armed Police CN, Hangzhou, Zhejiang, 310051, China
| | - Yiping Yin
- Department of Hospital-acquired infection control, Zhejiang Provincial General Hospital of Chinese People's Armed Police CN, Hangzhou, Zhejiang, 310051, China
| | - Beilei Pan
- Department of Clinical Laboratory, Hangzhou Women's Hospital (Hangzhou Matenal and Child Health Care Hospital), Hangzhou, Zhejiang, 310000, China
| | - Lihua Hu
- Department of Critical Care Medicine, Zhejiang Provincial General Hospital of Chinese People's Armed Police CN, Hangzhou, Zhejiang, 310051, China.
| | - Qiang Shen
- Hangzhou xixi Hospital, Hangzhou, Zhejiang, 310023, China.
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Yi M, Zou J, Zhao J, Tang Y, Yuan Y, Yang B, Huang J, Xia P, Xia Y. Emergence of optrA-Mediated Linezolid Resistance in Enterococcus faecium: A Molecular Investigation in a Tertiary Hospital of Southwest China from 2014-2018. Infect Drug Resist 2022; 15:13-20. [PMID: 35018102 PMCID: PMC8742577 DOI: 10.2147/idr.s339761] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/14/2021] [Indexed: 01/06/2023] Open
Abstract
Purpose To investigate the potential mechanism and molecular characteristics of linezolid-non-sensitive Enterococcus faecium from a tertiary hospital in southwest China and characterize the relevant plasmids. Patients and Methods Linezolid-non-sensitive Enterococcus faecium (LNSEFM) isolates collected from January 2014 to December 2018 were screened for resistant genes 23s rRNA, rplC, rplD, rplV, optrA, cfr, poxtA, by PCR. Molecular epidemiological analysis was performed by multilocus sequence typing (MLST). The optrA-and-poxtA co-harboring strain EFM_7150 was subjected to the whole genome sequencing (WGS) by Illumina HiSeq and Oxford Nanopore MinION. Results A total of 15 LNSEFM with linezolid MICs ranging from 4 to 16 mg/L were identified. About 66.7% (10/15) of isolates were linezolid-resistant. About 46.7% (7/15) of strains were positive for optrA. Two types of optrA variants (P and EYDNDM) were identified. About 13.3% (2/15) of isolates had poxtA. 1 harbored a L22 protein alteration (Ser77Thr). One isolate coharbored optrA (EYDNDM variant) and poxtA. There was no mutation in the gene that encoded the ribosomal protein L3/L4 or the domain V of 23S rRNA. No cfr gene was detected. Based on WGS data, optrA was associated with Tn558 inserted to radC gene and poxtA was flanked by IS1216E. Conclusion OptrA is primary mechanism in linezolid-resistant Enterococcus faecium. This is the first report ofoptrA variants P and EYDNDM identified in Enterococcus faecium and optrA-and-poxtA co-harboring Enterococcus faecium clinically in southwest China. Besides, Tn558 and IS1216Es may play an important role in the dissemination of optrA and poxtA, respectively. The findings revealed the potential threat to nosocomial infection by optrA and coexistence of optrA and poxtA in Enterococcus faecium. Thus, clinical surveillance of linezolid-resistant Enterococcus is urgently needed.
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Affiliation(s)
- Miao Yi
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Jiaqi Zou
- Department of Clinical Laboratory, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, People's Republic of China
| | - Jinxin Zhao
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Yu Tang
- Department of Laboratory Medicine, Chongqing University Three Gorges Hospital, Chongqing, People's Republic of China
| | - Yaling Yuan
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Bingxue Yang
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Jinzhu Huang
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Peiwen Xia
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China
| | - Yun Xia
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China
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Kim E, Shin SW, Kwak HS, Cha MH, Yang SM, Gwak YS, Woo GJ, Kim HY. Prevalence and Characteristics of Phenicol-Oxazolidinone Resistance Genes in Enterococcus Faecalis and Enterococcus Faecium Isolated from Food-Producing Animals and Meat in Korea. Int J Mol Sci 2021; 22:ijms222111335. [PMID: 34768762 PMCID: PMC8583520 DOI: 10.3390/ijms222111335] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/18/2021] [Accepted: 10/18/2021] [Indexed: 01/27/2023] Open
Abstract
The use of phenicol antibiotics in animals has increased. In recent years, it has been reported that the transferable gene mediates phenicol-oxazolidinone resistance. This study analyzed the prevalence and characteristics of phenicol-oxazolidinone resistance genes in Enterococcus faecalis and Enterococcus faecium isolated from food-producing animals and meat in Korea in 2018. Furthermore, for the first time, we reported the genome sequence of E. faecalis strain, which possesses the phenicol-oxazolidinone resistance gene on both the chromosome and plasmid. Among the 327 isolates, optrA, poxtA, and fexA genes were found in 15 (4.6%), 8 (2.5%), and 17 isolates (5.2%), respectively. Twenty E. faecalis strains carrying resistance genes belonged to eight sequence types (STs), and transferability was found in 17 isolates. The genome sequences revealed that resistant genes were present in the chromosome or plasmid, or both. In strains EFS17 and EFS108, optrA was located downstream of the ermA and ant(9)-1 genes. The strains EFS36 and EFS108 harboring poxtA-encoding plasmid cocarried fexA and cfr(D). These islands also contained IS1216E or the transposon Tn554, enabling the horizontal transfer of the phenicol-oxazolidinone resistance with other antimicrobial-resistant genes. Our results suggest that it is necessary to promote the prudent use of antibiotics through continuous monitoring and reevaluation.
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Affiliation(s)
- Eiseul Kim
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Korea; (E.K.); (S.-W.S.); (H.-S.K.); (S.-M.Y.); (Y.-S.G.)
| | - So-Won Shin
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Korea; (E.K.); (S.-W.S.); (H.-S.K.); (S.-M.Y.); (Y.-S.G.)
| | - Hyo-Sun Kwak
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Korea; (E.K.); (S.-W.S.); (H.-S.K.); (S.-M.Y.); (Y.-S.G.)
| | - Min-Hyeok Cha
- Laboratory of Food Safety and Evaluation, Department of Biotechnology, Korea University Graduate School, Seoul 02841, Korea;
| | - Seung-Min Yang
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Korea; (E.K.); (S.-W.S.); (H.-S.K.); (S.-M.Y.); (Y.-S.G.)
| | - Yoon-Soo Gwak
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Korea; (E.K.); (S.-W.S.); (H.-S.K.); (S.-M.Y.); (Y.-S.G.)
| | - Gun-Jo Woo
- Laboratory of Food Safety and Evaluation, Department of Biotechnology, Korea University Graduate School, Seoul 02841, Korea;
- Correspondence: (G.-J.W.); (H.-Y.K.); Tel.: +82-2-3290-3021 (G.-J.W.); +82-31-201-2123 (H.-Y.K.); Fax: +82-2-3290-3581 (G.-J.W.); +82-31-204-8116 (H.-Y.K.)
| | - Hae-Yeong Kim
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Korea; (E.K.); (S.-W.S.); (H.-S.K.); (S.-M.Y.); (Y.-S.G.)
- Correspondence: (G.-J.W.); (H.-Y.K.); Tel.: +82-2-3290-3021 (G.-J.W.); +82-31-201-2123 (H.-Y.K.); Fax: +82-2-3290-3581 (G.-J.W.); +82-31-204-8116 (H.-Y.K.)
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Turner AM, Lee JYH, Gorrie CL, Howden BP, Carter GP. Genomic Insights Into Last-Line Antimicrobial Resistance in Multidrug-Resistant Staphylococcus and Vancomycin-Resistant Enterococcus. Front Microbiol 2021; 12:637656. [PMID: 33796088 PMCID: PMC8007764 DOI: 10.3389/fmicb.2021.637656] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/25/2021] [Indexed: 12/17/2022] Open
Abstract
Multidrug-resistant Staphylococcus and vancomycin-resistant Enterococcus (VRE) are important human pathogens that are resistant to most clinical antibiotics. Treatment options are limited and often require the use of 'last-line' antimicrobials such as linezolid, daptomycin, and in the case of Staphylococcus, also vancomycin. The emergence of resistance to these last-line antimicrobial agents is therefore of considerable clinical concern. This mini-review provides an overview of resistance to last-line antimicrobial agents in Staphylococcus and VRE, with a particular focus on how genomics has provided critical insights into the emergence of resistant clones, the molecular mechanisms of resistance, and the importance of mobile genetic elements in the global spread of resistance to linezolid.
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Affiliation(s)
- Adrianna M Turner
- Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Jean Y H Lee
- Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia.,Department of Infectious Diseases, Monash Health, Melbourne, VIC, Australia
| | - Claire L Gorrie
- Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia.,Antimicrobial Reference and Research Unit, Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Benjamin P Howden
- Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia.,Antimicrobial Reference and Research Unit, Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia.,Department of Infectious Diseases, Austin Health, Melbourne, VIC, Australia
| | - Glen P Carter
- Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia.,Antimicrobial Reference and Research Unit, Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia
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Jiang L, Xie N, Chen M, Liu Y, Wang S, Mao J, Li J, Huang X. Synergistic Combination of Linezolid and Fosfomycin Closing Each Other's Mutant Selection Window to Prevent Enterococcal Resistance. Front Microbiol 2021; 11:605962. [PMID: 33633692 PMCID: PMC7899970 DOI: 10.3389/fmicb.2020.605962] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/30/2020] [Indexed: 12/21/2022] Open
Abstract
Enterococci, the main pathogens associated with nosocomial infections, are resistant to many common antibacterial drugs including β-lactams, aminoglycosides, etc. Combination therapy is considered an effective way to prevent bacterial resistance. Preliminary studies in our group have shown that linezolid combined with fosfomycin has synergistic or additive antibacterial activity against enterococci, while the ability of the combination to prevent resistance remains unknown. In this study, we determined mutant prevention concentration (MPC) and mutant selection window (MSW) of linezolid, fosfomycin alone and in combination including different proportions for five clinical isolates of Enterococcus and characterized the resistance mechanism for resistant mutants. The results indicated that different proportions of linezolid combined with fosfomycin had presented different MPCs and MSWs. Compared with linezolid or fosfomycin alone, the combination can restrict the enrichment of resistant mutants at a lower concentration. A rough positive correlation between the selection index (SI) of the two agents in combination and the fractional inhibitory concentration index (FICI) of the combination displayed that the smaller FICI of linezolid and fosfomycin, the more probable their MSWs were to close each other. Mutations in ribosomal proteins (L3 and L4) were the mechanisms for linezolid resistant mutants. Among the fosfomycin-resistant mutants, only two strains have detected the MurA gene mutation related to fosfomycin resistance. In conclusion, the synergistic combination of linezolid and fosfomycin closing each other’s MSW could effectively suppress the selection of enterococcus resistant mutants, suggesting that the combination may be an alternative for preventing enterococcal resistance. In this study, the resistance mechanism of fosfomycin remains to be further studied.
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Affiliation(s)
- Lifang Jiang
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, China.,Anhui Province Key Laboratory of Major Autoimmune Diseases, School of Pharmacy, Anhui Institute of Innovative Drugs, Anhui Medical University, Hefei, China
| | - Na Xie
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, China.,Anhui Province Key Laboratory of Major Autoimmune Diseases, School of Pharmacy, Anhui Institute of Innovative Drugs, Anhui Medical University, Hefei, China
| | - Mingtao Chen
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, China.,Anhui Province Key Laboratory of Major Autoimmune Diseases, School of Pharmacy, Anhui Institute of Innovative Drugs, Anhui Medical University, Hefei, China
| | - Yanyan Liu
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Shuaishuai Wang
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, China.,Anhui Province Key Laboratory of Major Autoimmune Diseases, School of Pharmacy, Anhui Institute of Innovative Drugs, Anhui Medical University, Hefei, China
| | - Jun Mao
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, China.,Anhui Province Key Laboratory of Major Autoimmune Diseases, School of Pharmacy, Anhui Institute of Innovative Drugs, Anhui Medical University, Hefei, China
| | - Jiabin Li
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xiaohui Huang
- Department of Basic and Clinical Pharmacology, School of Pharmacy, Anhui Medical University, Hefei, China.,Anhui Province Key Laboratory of Major Autoimmune Diseases, School of Pharmacy, Anhui Institute of Innovative Drugs, Anhui Medical University, Hefei, China
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Jung YH, Cha MH, Woo GJ, Chi YM. Characterization of oxazolidinone and phenicol resistance genes in non-clinical enterococcal isolates from Korea. J Glob Antimicrob Resist 2021; 24:363-369. [PMID: 33515778 DOI: 10.1016/j.jgar.2021.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 11/29/2020] [Accepted: 01/18/2021] [Indexed: 10/22/2022] Open
Abstract
OBJECTIVES To investigate the distribution and genetic characteristics of linezolid-resistant enterococci. METHODS Enterococcus faecalis and Enterococcus faecium strains were isolated from pigs, equipment, grounds, and employees of 19 Korean swine farms in 2017. Antimicrobial susceptibility testing was then performed and linezolid resistance genes were detected via PCR. For genetic epidemiological characterization, multilocus sequence typing and whole-genome sequencing data were analysed. RESULTS Twenty-eightE. faecalis and five E. faecium strains were isolated from 1026 samples obtained from the 19 farms. Ten sequence types were identified among the E. faecalis strains, of which ST256 (42.9%) and ST86 (25%) were the most abundant. The oxazolidinone and phenicol resistance genes poxtA, optrA, and fexA were detected in isolates of E. faecalis (100%, 85.7%, and 67.9%, respectively) and E. faecium (100%, 60%, and 80%, respectively). The minimum inhibitory concentrations of linezolid in these isolates ranged from 2 mg/L to 12 mg/L. The whole-genome sequencing data indicated that fexA was located upstream of poxtA. CONCLUSIONS This is the first study to report the detection of poxtA in isolates that were both susceptible and resistant to linezolid in Korea. These results demonstrate the importance of antimicrobial resistance monitoring programmes, including regular antimicrobial susceptibility testing and resistance gene expression analysis, to facilitate the control of the spread of antibiotic resistance in non-clinical settings in Korea.
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Affiliation(s)
- Young-Hee Jung
- Division of Biotechnology, College of Life Sciences, Korea University, Seoul, 02841, Republic of Korea
| | - Min-Hyeok Cha
- Laboratory of Food Safety and Evaluation, Department of Biotechnology, Korea University Graduate School, Seoul, 02841, Republic of Korea
| | - Gun-Jo Woo
- Laboratory of Food Safety and Evaluation, Department of Biotechnology, Korea University Graduate School, Seoul, 02841, Republic of Korea.
| | - Young-Min Chi
- Division of Biotechnology, College of Life Sciences, Korea University, Seoul, 02841, Republic of Korea.
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Park K, Jeong YS, Chang J, Sung H, Kim MN. Emergence of optrA-Mediated Linezolid-Nonsusceptible Enterococcus faecalis in a Tertiary Care Hospital. Ann Lab Med 2020; 40:321-325. [PMID: 32067432 PMCID: PMC7054691 DOI: 10.3343/alm.2020.40.4.321] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/04/2019] [Accepted: 02/05/2020] [Indexed: 11/30/2022] Open
Abstract
This study investigated resistance mechanisms and epidemiology of emerging linezolid-nonsusceptible Enterococcus faecalis (LNSEF) in a tertiary care hospital. LNSEF isolated from clinical samples were collected from November 2017 to June 2019. The isolates were investigated for linezolid resistance and the associated molecular mechanisms, including mutations of 23S rRNA domain V and acquisition of the cfr or optrA resistance gene. We used pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing for the molecular typing of the isolates. Among 4,318 E. faecalis isolates, 10 (0.23%) were linezolid-nonsusceptible. All LNSEF isolates were optrA-positive and cfr-negative. Of these isolates, five were sequence type (ST) 476, two ST585, one ST16, one ST16-like, and one ST480. Six LNSEF isolates obtained in the first year clustered to three types in the PFGE analysis: two ST476 isolates of type A, two ST585 isolates of type B, and two ST16 or ST16-like isolates of type C. Seven cases were of community-onset and three were hospital acquired, but total of eight were healthcare-associated including five community-onset. None of the patients had a history of linezolid treatment, and in one patient, we detected linezolid-susceptible E. faecalis one month before LNSEF detection. In conclusion, heterogenous clones of optrA-positive LNSEF emerged in the hospital mainly via community-onset.
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Affiliation(s)
- Kuenyoul Park
- Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Korea
| | - Yun Sil Jeong
- Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Korea
| | - Jeonghyun Chang
- Department of Laboratory Medicine, Inje University Ilsan Paik Hospital, Goyang, Korea
| | - Heungsup Sung
- Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Korea
| | - Mi Na Kim
- Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Korea.
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Kerschner H, Rosel AC, Hartl R, Hyden P, Stoeger A, Ruppitsch W, Allerberger F, Apfalter P. Oxazolidinone Resistance Mediated by optrA in Clinical Enterococcus faecalis Isolates in Upper Austria: First Report and Characterization by Whole Genome Sequencing. Microb Drug Resist 2020; 27:685-690. [PMID: 33090061 DOI: 10.1089/mdr.2020.0098] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The genetic mechanisms associated with acquisition of linezolid (LZD) resistance are diverse, including point mutations in the V domain of the 23S rRNA and the 50S ribosomal proteins as well as cfr, optrA, and/or poxtA genes, which may be plasmid- or chromosomally encoded. The aim of this study was to investigate through Whole Genome Sequencing (WGS)-based typing the presence and location of genes and point mutations associated with LZD resistance in two Enterococcus faecalis isolates from Upper Austrian patients. The isolates were retrieved during screening by LZD disk diffusion test of a total of 911 clinical E. faecalis isolates in 2017. The two E. faecalis isolates had LZD minimum inhibitory concentrations of 8 and 32 mg/L and were optrA-positive (ST476 and ST585). Bioinformatic analysis revealed the presence of optrA located in the chromosome of both isolates. One isolate carried the optrA gene in the transposon 6674, previously reported as chromosomally encoded, and the second isolate in fragments originating from the integrative plasmid pEF10748. Additional mechanisms of LZD resistance on the 23S rRNA and the 50S ribosomal proteins were detected. None of the patients reported travels to geographical areas with high LZD resistance or previous LZD treatments. This is the first report of optrA carrying E. faecalis, including characterization by WGS from Austria. LZD resistance in a low-prevalence setting is of concern and should be further monitored.
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Affiliation(s)
- Heidrun Kerschner
- National Reference Center for Antimicrobial Resistance and Nosocomial Infections (NRZ), Institute for Hygiene, Microbiology and Tropical Medicine, Ordensklinikum Linz Elisabethinen, Linz, Austria
| | - Adriana Cabal Rosel
- AGES-Austrian Agency for Health and Food Safety, Institute of Medical Microbiology and Hygiene, Vienna, Austria
| | - Rainer Hartl
- National Reference Center for Antimicrobial Resistance and Nosocomial Infections (NRZ), Institute for Hygiene, Microbiology and Tropical Medicine, Ordensklinikum Linz Elisabethinen, Linz, Austria
| | - Patrick Hyden
- CUBE, Division of Computational Systems Biology, University of Vienna, Vienna, Austria
| | - Anna Stoeger
- AGES-Austrian Agency for Health and Food Safety, Institute of Medical Microbiology and Hygiene, Vienna, Austria
| | - Werner Ruppitsch
- AGES-Austrian Agency for Health and Food Safety, Institute of Medical Microbiology and Hygiene, Vienna, Austria
| | - Franz Allerberger
- AGES-Austrian Agency for Health and Food Safety, Institute of Medical Microbiology and Hygiene, Vienna, Austria
| | - Petra Apfalter
- National Reference Center for Antimicrobial Resistance and Nosocomial Infections (NRZ), Institute for Hygiene, Microbiology and Tropical Medicine, Ordensklinikum Linz Elisabethinen, Linz, Austria
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10
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Zou J, Xia Y. Molecular characteristics and risk factors associated with linezolid-resistant Enterococcus faecalis infection in Southwest China. J Glob Antimicrob Resist 2020; 22:504-510. [DOI: 10.1016/j.jgar.2020.03.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 02/29/2020] [Accepted: 03/28/2020] [Indexed: 11/25/2022] Open
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11
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Mechanisms of Linezolid Resistance Among Enterococci of Clinical Origin in Spain-Detection of optrA- and cfr(D)-Carrying E. faecalis. Microorganisms 2020; 8:microorganisms8081155. [PMID: 32751552 PMCID: PMC7464793 DOI: 10.3390/microorganisms8081155] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/24/2020] [Accepted: 07/28/2020] [Indexed: 12/12/2022] Open
Abstract
The mechanisms of linezolid resistance among 13 E. faecalis and 6 E. faecium isolates, recovered from six Spanish hospitals during 2017–2018, were investigated. The presence of acquired linezolid resistance genes and mutations in 23S rDNA and in genes encoding for ribosomal proteins was analyzed by PCR and amplicon sequencing. Moreover, the susceptibility to 18 antimicrobial agents was investigated, and the respective molecular background was elucidated by PCR-amplicon sequencing and whole genome sequencing. The transferability of the linezolid resistance genes was evaluated by filter-mating experiments. The optrA gene was detected in all 13 E. faecalis isolates; and one optrA-positive isolate also carried the recently described cfr(D) gene. Moreover, one E. faecalis isolate displayed the nucleotide mutation G2576T in the 23S rDNA. This mutation was also present in all six E. faecium isolates. All linezolid-resistant enterococci showed a multiresistance phenotype and harbored several antimicrobial resistance genes, as well as many virulence determinants. The fexA gene was located upstream of the optrA gene in 12 of the E. faecalis isolates. Moreover, an erm(A)-like gene was located downstream of optrA in two isolates recovered from the same hospital. The optrA gene was transferable in all but one E. faecalis isolates, in all cases along with the fexA gene. The cfr(D) gene was not transferable. The presence of optrA and mutations in the 23S rDNA are the main mechanisms of linezolid resistance among E. faecalis and E. faecium, respectively. We report the first description of the cfr(D) gene in E. faecalis. The presence of the optrA and cfr(D) genes in Spanish hospitals is a public health concern.
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12
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Zou J, Tang Z, Yan J, Liu H, Chen Y, Zhang D, Zhao J, Tang Y, Zhang J, Xia Y. Dissemination of Linezolid Resistance Through Sex Pheromone Plasmid Transfer in Enterococcus faecalis. Front Microbiol 2020; 11:1185. [PMID: 32582110 PMCID: PMC7288747 DOI: 10.3389/fmicb.2020.01185] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 05/11/2020] [Indexed: 12/19/2022] Open
Abstract
Despite recent recognition of the ATP-binding cassette protein OptrA as an important mediator of linezolid resistance in Enterococcus faecalis worldwide, the mechanisms of optrA gene acquisition and transfer remain poorly understood. In this study, we performed comprehensive molecular and phenotypic profiling of 44 optrA-carrying E. faecalis clinical isolates with linezolid resistance. Pulse-field gel electrophoresis and DNA hybridization revealed the presence of optrA in the plasmid in 26 (59%) isolates and in the chromosome in 18 (41%) isolates. Conjugation experiments showed a successful transfer of optrA in 88.5% (23/26) of isolates carrying optrA in plasmids while no transfer occurred in any isolates carrying optrA in the chromosome (0/18). All 23 transconjugants exhibited in vitro resistance to linezolid and several other antibiotics and were confirmed to contain optrA and other resistance genes. Plasmid typing demonstrated a predominance (18/23,78%) of rep 9-type plasmids (pCF10 prototype) known to be the best studied sex pheromone responsive plasmids. Full plasmid genome sequencing of one isolate revealed the presence of drug resistance genes (optrA and fexA) and multiple sex pheromone response genes in the same plasmid, which represents the first sex pheromone responsive plasmid carrying optrA from a clinical isolate. PCR-based genotyping revealed the presence of three key sex pheromone response genes (prgA, prgB, and prgC) in 23 optrA-carrying isolates. Finally, functional studies of these isolates by clumping induction assay detected different degrees of clumping in 17 isolates. Our analysis suggests that optrA-mediated linezolid resistance can be widely disseminated through sex pheromone plasmid transfer.
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Affiliation(s)
- Jiaqi Zou
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Zhaobing Tang
- Department of Urologic Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jia Yan
- Department of Laboratory Medicine, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Hang Liu
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yingzhu Chen
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Dawei Zhang
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jinxin Zhao
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yu Tang
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jing Zhang
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yun Xia
- Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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