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Càmara J, Camoez M, Tubau F, Pujol M, Ayats J, Ardanuy C, Domínguez MÁ. Detection of the Novel optrA Gene Among Linezolid-Resistant Enterococci in Barcelona, Spain. Microb Drug Resist 2018; 25:87-93. [PMID: 30153086 DOI: 10.1089/mdr.2018.0028] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The purpose of this study was to describe the presence of the novel optrA gene among clinical isolates of enterococci in a Spanish teaching hospital (May 2016-April 2017). optrA and cfr genes were screened by PCR in all isolates showing linezolid minimal inhibitory concentration (MIC) ≥4 mg/L. The genetic relatedness of the isolates, the presence of resistance and virulence genes, and the genetic environment of optrA were assessed by whole-genome sequencing (WGS). Six of 1,640 enterococci had linezolid MIC ≥4 mg/L. Among them, the optrA gene was detected in five Enterococcus faecalis isolated from unrelated patients. Although none of them had received linezolid or chloramphenicol, all had antecedents of recent quinolone consumption. WGS analysis revealed the existence of two different genotypes: ST585 and ST474. cfr was not detected in any of the isolates. No mutations were detected among the 23S ribosomal RNA and the ribosomal proteins L3, L4, and L22. Both genotypes also carried genes related to aminoglycoside, lincosamide, macrolide, phenicol, and tetracycline resistance. Detection of optrA in a setting with low linezolid consumption and among patients without antecedents of oxazolidinone therapy is of concern.
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Affiliation(s)
- Jordi Càmara
- 1 Microbiology Department, Hospital Universitari de Bellvitge-Universitat de Barcelona-IDIBELL, L'Hospitalet de Llobregat , Barcelona, Spain
| | - Mariana Camoez
- 1 Microbiology Department, Hospital Universitari de Bellvitge-Universitat de Barcelona-IDIBELL, L'Hospitalet de Llobregat , Barcelona, Spain .,2 Spanish Network for Research in Infectious Diseases (REIPI), Instituto de Salud Carlos III , Madrid, Spain
| | - Fe Tubau
- 1 Microbiology Department, Hospital Universitari de Bellvitge-Universitat de Barcelona-IDIBELL, L'Hospitalet de Llobregat , Barcelona, Spain .,3 CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - Miquel Pujol
- 2 Spanish Network for Research in Infectious Diseases (REIPI), Instituto de Salud Carlos III , Madrid, Spain .,4 Infectious Diseases Department, Hospital Universitari de Bellvitge-Universitat de Barcelona-IDIBELL, L'Hospitalet de Llobregat , Barcelona, Spain
| | - Josefina Ayats
- 1 Microbiology Department, Hospital Universitari de Bellvitge-Universitat de Barcelona-IDIBELL, L'Hospitalet de Llobregat , Barcelona, Spain .,3 CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - Carmen Ardanuy
- 1 Microbiology Department, Hospital Universitari de Bellvitge-Universitat de Barcelona-IDIBELL, L'Hospitalet de Llobregat , Barcelona, Spain .,3 CIBER de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - M Ángeles Domínguez
- 1 Microbiology Department, Hospital Universitari de Bellvitge-Universitat de Barcelona-IDIBELL, L'Hospitalet de Llobregat , Barcelona, Spain .,2 Spanish Network for Research in Infectious Diseases (REIPI), Instituto de Salud Carlos III , Madrid, Spain
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Kampmeier S, Kossow A, Clausen LM, Knaack D, Ertmer C, Gottschalk A, Freise H, Mellmann A. Hospital acquired vancomycin resistant enterococci in surgical intensive care patients - a prospective longitudinal study. Antimicrob Resist Infect Control 2018; 7:103. [PMID: 30155243 PMCID: PMC6108103 DOI: 10.1186/s13756-018-0394-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 08/14/2018] [Indexed: 11/10/2022] Open
Abstract
Background Vancomycin resistant enterococci (VRE) occur with enhanced frequency in hospitalised patients. This study elucidates the prevalence of VRE on admission among surgical intensive care unit (SICU) patients, whether these patients are at special risk for VRE acquisition and which risk factors support this process. Methods Patients admitted to SICUs of the University Hospital Münster were examined during August-October 2017. VRE screening was performed within 48 h after admission and directly prior to discharge of patients. In parallel risk factors were recorded to estimate their effect on VRE acquisition during SICU stay. Results In total, 374 patients (68% male) with a median age of 66 years were admitted to one of the SICUs during the investigation period. Of all, 336 patients (89.8%) were screened on admission and 268 (71.7%) on discharge. Nine patients were admitted with previously known VRE colonisation. Twelve (3.6%) further patients were VRE positive on admission. During ICU stay, eight (3.0%) additional patients turned out to be VRE colonised. Risk factors found to be significantly associated with VRE acquisition were median length of stay on the ICU (14 vs. 3 days; p = 0.01), long-term dialysis (12.5% vs. 2.0% of patients; p = 0.05), and antibiotic treatment with flucloxacillin (28.6% vs. 7.2% of patients; p = 0.01) or piperacillin/tazobactam (57.1% vs. 26.6% of patients; p = 0.01). Conclusions SICU patients are not at special risk for VRE acquisition. Previous stay on a SICU should therefore not be considered as specific risk factor for VRE colonisation.
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Affiliation(s)
- Stefanie Kampmeier
- Institute of Hygiene, University Hospital Münster, Robert-Koch-Strasse 41, 48149 Münster, Germany
| | - Annelene Kossow
- Institute of Hygiene, University Hospital Münster, Robert-Koch-Strasse 41, 48149 Münster, Germany
| | - Larissa Monika Clausen
- Institute of Hygiene, University Hospital Münster, Robert-Koch-Strasse 41, 48149 Münster, Germany
| | - Dennis Knaack
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
| | - Christian Ertmer
- Department of Anaesthesiology, Intensive Care and Pain Medicine, University Hospital Münster, Münster, Germany
| | - Antje Gottschalk
- Department of Anaesthesiology, Intensive Care and Pain Medicine, University Hospital Münster, Münster, Germany
| | - Hendrik Freise
- Department of Anaesthesiology, Intensive Care and Pain Medicine, University Hospital Münster, Münster, Germany
| | - Alexander Mellmann
- Institute of Hygiene, University Hospital Münster, Robert-Koch-Strasse 41, 48149 Münster, Germany
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Cai J, Schwarz S, Chi D, Wang Z, Zhang R, Wang Y. Faecal carriage of optrA-positive enterococci in asymptomatic healthy humans in Hangzhou, China. Clin Microbiol Infect 2018; 25:630.e1-630.e6. [PMID: 30076974 DOI: 10.1016/j.cmi.2018.07.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 07/19/2018] [Accepted: 07/21/2018] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To investigate the faecal carriage of optrA-positive enterococci among asymptomatic healthy humans in Hangzhou, China, and to characterize the genetic context of optrA. METHODS A total of 3458 stool samples from healthy individuals were collected and cultured on a selective medium containing 10 mg/L florfenicol and resulting enterococci were screened for the presence of optrA by PCR. OptrA variants were determined by amino acid sequence comparison with the original OptrA from Enterococcus faecalis E349. Whole genome sequencing and PCR mapping were performed to obtain and analyse the genetic environment of optrA. RESULTS Similar optrA carriage rates (∼3.5%) were detected in samples from adults (55/1558) and children (66/1900). Linezolid resistance rates for E. faecalis, Enterococcus faecium and other Enterococcus species were 58.5% (38/65), 42.3% (11/26) and 0% (0/31), respectively. Nineteen OptrA variants exhibiting different linezolid MICs were identified. Isolates carrying wild-type OptrA and variants RDK, KLDP, KD, D, RDKP, and EDP generally demonstrated linezolid MICs ≥8 mg/L. The OptrA variants, with fexA upstream and erm(A) downstream, were flanked by IS1216E at one or both ends. The fexA-optrA(wild-type) was located downstream of a Tn554 transposon, and was inserted into the radC gene. The EDM variant was detected in 31/73 enterococci with linezolid MICs ≤4 mg/L. Despite the variable genetic context, Tn558-araC-optrA(EDM)-erm(A)-met was the most common gene array. CONCLUSIONS This study revealed a correlation between linezolid MIC, genetic context and OptrA variant. Intestinal colonization of healthy individuals by optrA-positive enterococci is a concern, and active epidemiological surveillance of optrA is warranted.
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Affiliation(s)
- J Cai
- Clinical Microbiology Laboratory, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, China
| | - S Schwarz
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, China; Institute of Microbiology and Epizootics, Centre for Infection Medicine, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - D Chi
- Department of Laboratory, Children's Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, China
| | - Z Wang
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - R Zhang
- Clinical Microbiology Laboratory, The Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou, China.
| | - Y Wang
- Beijing Advanced Innovation Centre for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, China
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Yan J, Xia Y, Yang M, Zou J, Chen Y, Zhang D, Ma L. Quantitative Proteomics Analysis of Membrane Proteins in Enterococcus faecalis With Low-Level Linezolid-Resistance. Front Microbiol 2018; 9:1698. [PMID: 30100900 PMCID: PMC6072972 DOI: 10.3389/fmicb.2018.01698] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 07/09/2018] [Indexed: 11/26/2022] Open
Abstract
Despite increasing reports of low-level linezolid-resistant enterococci worldwide, the mechanism of this resistance remains poorly understood. Previous transcriptome studies of low-level linezolid-resistant Enterococcus faecalis isolates have demonstrated a number of significantly up-regulated genes potentially involved in mediation of drug resistance. However, whether the transcriptome faithfully reflects the proteome remains unknown. In this study, we performed quantitative proteomics analysis of membrane proteins in an E. faecalis isolate (P10748) with low-level linezolid-resistance in comparison with two linezolid-susceptible strains 3138 and ATCC 29212, all of which have been previously investigated by whole transcriptome analysis. A total of 8,197 peptides associated with 1,170 proteins were identified in all three isolates with false discovery rate (FDR) at 1% and P < 0.05. There were 14 significantly up-regulated and 6 significantly down-regulated proteins in strain P10748 compared to strains 3138 and ATCC 29212, which were in general positively correlated with transcription levels revealed in previous transcriptome studies. Our analysis suggests that the low-level linezolid-resistance in E. faecalis is conferred primarily by the ATP-binding cassette protein OptrA through ribosomal protection and, possibly, also by the enterococcal surface protein (Esp) and other proteins through biofilm formation. The genetic transfer of optrA is potentially regulated by the surface exclusion protein Sea1, conjugal transfer protein TraB, replication protein RepA and XRE family transcription regulator protein. This report represents the first investigation of the mechanisms of linezolid-resistance in E. faecalis by a quantitative proteomics approach.
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Affiliation(s)
- Jia Yan
- Department of Clinical Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yun Xia
- Department of Clinical Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Mi Yang
- Department of Clinical Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jiaqi Zou
- Department of Clinical Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yingzhu Chen
- Department of Clinical Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Dawei Zhang
- Department of Clinical Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Liang Ma
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD, United States
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Freitas AR, Elghaieb H, León-Sampedro R, Abbassi MS, Novais C, Coque TM, Hassen A, Peixe L. Detection of optrA in the African continent (Tunisia) within a mosaic Enterococcus faecalis plasmid from urban wastewaters. J Antimicrob Chemother 2018; 72:3245-3251. [PMID: 29029072 DOI: 10.1093/jac/dkx321] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 08/01/2017] [Indexed: 01/11/2023] Open
Abstract
Objectives Oxazolidinone resistance is a serious limitation in the treatment of MDR Enterococcus infections. Plasmid-mediated oxazolidinone resistance has been strongly linked to animals where the use of phenicols might co-select resistance to both antibiotic families. Our goal was to assess the diversity of genes conferring phenicol/oxazolidinone resistance among diverse enterococci and to characterize the optrA genetic environment. Methods Chloramphenicol-resistant isolates (>16 mg/L, n = 245) from different sources (hospitals/healthy humans/wastewaters/animals) in Portugal, Angola and Tunisia (1996-2016) were selected. Phenicol (eight cat variants, fexA, fexB) or phenicol + oxazolidinone [cfr, cfr(B), optrA] resistance genes were searched for by PCR. Susceptibility (disc diffusion/microdilution), filter mating, stability of antibiotic resistance (500 bacterial generations), plasmid typing (S1-PFGE/hybridization), MLST and WGS (Illumina-HiSeq) were performed for optrA-positive isolates. Results Resistance to phenicols (n = 181, 74%) and phenicols + oxazolidinones (n = 2, 1%) was associated with the presence of cat(A-8) (40%, predominant in hospitals and swine), cat(A-7) (29%, predominant in poultry and healthy humans), cat(A-9) (2%), fexB (2%) and fexA + optrA (1%). fexA and optrA genes were co-located in a transferable plasmid (pAF379, 72 918 bp) of two ST86 MDR Tunisian Enterococcus faecalis (wastewaters) carrying several putative virulence genes. MICs of chloramphenicol, linezolid and tedizolid were stably maintained at 64, 4 and 1 mg/L, respectively. The chimeric pAF379 comprised relics of genetic elements from different Gram-positive bacteria and origins (human/porcine). Conclusions To the best of our knowledge, we report the first detection of optrA in an African country (Tunisia) within a transferable mosaic plasmid of different origins. Its identification in isolates from environmental sources is worrisome and alerts for the need of a concerted global surveillance on the occurrence and spread of optrA.
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Affiliation(s)
- Ana R Freitas
- UCIBIO/REQUIMTE, Departamento de Ciências Biológicas, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Houyem Elghaieb
- Université de Tunis El Manar, Institut de la Recherche Vétérinaire de Tunisie, 20 rue Jebel Lakhdhar, Bab Saadoun, Tunis, Tunisia
| | - Ricardo León-Sampedro
- Servicio de Microbiología, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Centros de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBER-ESP), Barcelona, Spain
| | - Mohamed Salah Abbassi
- Université de Tunis El Manar, Institut de la Recherche Vétérinaire de Tunisie, 20 rue Jebel Lakhdhar, Bab Saadoun, Tunis, Tunisia
| | - Carla Novais
- UCIBIO/REQUIMTE, Departamento de Ciências Biológicas, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
| | - Teresa M Coque
- Servicio de Microbiología, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.,Centros de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBER-ESP), Barcelona, Spain
| | - Abdennaceur Hassen
- Laboratoire de Traitement des Eaux Usées, Centre des Recherches et des Technologies des Eaux (CERTE), Technopole Borj Cédria, Soliman, Tunisia
| | - Luisa Peixe
- UCIBIO/REQUIMTE, Departamento de Ciências Biológicas, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal
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A high incidence and coexistence of multiresistance genes cfr and optrA among linezolid-resistant enterococci isolated from a teaching hospital in Wenzhou, China. Eur J Clin Microbiol Infect Dis 2018; 37:1441-1448. [DOI: 10.1007/s10096-018-3269-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 04/30/2018] [Indexed: 02/04/2023]
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Zheng JX, Wu Y, Lin ZW, Pu ZY, Yao WM, Chen Z, Li DY, Deng QW, Qu D, Yu ZJ. Characteristics of and Virulence Factors Associated with Biofilm Formation in Clinical Enterococcus faecalis Isolates in China. Front Microbiol 2017; 8:2338. [PMID: 29225595 PMCID: PMC5705541 DOI: 10.3389/fmicb.2017.02338] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 11/13/2017] [Indexed: 01/12/2023] Open
Abstract
Enterococcus faecalis biofilm traits and distribution characteristics in China have not been clarified. This study aimed to determine the prevalence and characteristics of E. faecalis biofilm formation in a sample of clinical isolates and to explore the virulence factors associated with biofilm formation in those isolates. A total of 265 E. faecalis isolates were collected from patients in Shenzhen, China. Virulence genes were detected within the genomes of the microbes by polymerase chain reaction. The isolates were subjected to multilocus sequence typing (MLST) based on housekeeping genes. Biofilms were detected by crystal violet staining. The expression levels of the clinical E. faecalis isolates’ genes were determined by quantitative real-time polymerase chain reaction. The prevalence of biofilm formation among E. faecalis clinical isolates was 47.2%. MLST yielded 44 different sequence types (STs). The main STs were ST16 and ST179; the ST16 isolates were more likely to form strong or medium biofilm than the ST179 isolates (p < 0.001). Strong or medium biofilm formation was more common in linezolid-resistant isolates than in linezolid-sensitive isolates (p = 0.001). Biofilm formation was more frequently detected in enterococcal surface protein (esp+), surface aggregating protein (asa1+), cytolysin A (cylA+), or aggregation substance (agg+) positive isolates than in isolates that were negative (-) for these virulence factors. Multivariate regression analysis indicated that cylA [odds ratio (OR) 4.083, p < 0.001] was a risk factor for weak biofilm formation, and that esp (OR 8.207, p < 0.001) was a risk factor for strong or medium biofilm formation. The expression of cylA was raised (4.02 to 6.00-fold) in weak biofilm isolates compared to the biofilm-negative isolates, and the expression of esp was greatly elevated (11.39 to 134.08-fold) in strong biofilm isolates compared to biofilm-negative isolates. In conclusion, the ST16 classification and linezolid resistance were positively associated with strong/medium biofilm formation in clinical E. faecalis isolates. cylA was associated with weak biofilm formation, and esp was only associated with strong or medium biofilm formation of the clinical E. faecalis isolates.
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Affiliation(s)
- Jin-Xin Zheng
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infection, Shenzhen Nanshan People's Hospital of Shenzhen University, Shenzhen, China
| | - Yang Wu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Science and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, China
| | - Zhi-Wei Lin
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infection, Shenzhen Nanshan People's Hospital of Shenzhen University, Shenzhen, China
| | - Zhang-Ya Pu
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infection, Shenzhen Nanshan People's Hospital of Shenzhen University, Shenzhen, China
| | - Wei-Ming Yao
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infection, Shenzhen Nanshan People's Hospital of Shenzhen University, Shenzhen, China
| | - Zhong Chen
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infection, Shenzhen Nanshan People's Hospital of Shenzhen University, Shenzhen, China
| | - Duo-Yun Li
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infection, Shenzhen Nanshan People's Hospital of Shenzhen University, Shenzhen, China
| | - Qi-Wen Deng
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infection, Shenzhen Nanshan People's Hospital of Shenzhen University, Shenzhen, China
| | - Di Qu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Science and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, China
| | - Zhi-Jian Yu
- Department of Infectious Diseases and Shenzhen Key Laboratory for Endogenous Infection, Shenzhen Nanshan People's Hospital of Shenzhen University, Shenzhen, China
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Lee SM, Huh HJ, Song DJ, Shim HJ, Park KS, Kang CI, Ki CS, Lee NY. Resistance mechanisms of linezolid-nonsusceptible enterococci in Korea: low rate of 23S rRNA mutations in Enterococcus faecium. J Med Microbiol 2017; 66:1730-1735. [PMID: 29111969 DOI: 10.1099/jmm.0.000637] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
PURPOSE To investigate linezolid-resistance mechanisms in linezolid-nonsusceptible enterococci (LNSE) isolated from a tertiary hospital in Korea. METHODOLOGY Enterococcal isolates exhibiting linezolid MICs ≥4 mg l-1 that were isolated between December 2011 and May 2016 were investigated by PCR and sequencing for mutations in 23S rRNA or ribosomal proteins (L3, L4 and L22) and for the presence of cfr, cfr(B) and optrA genes.Results/Key findings. Among 135 LNSE (87 Enterococcus faecium and 48 Enterococcus faecalis isolates), 39.1 % (34/87) of E. faecium and 18.8 % (9/48) of E. faecalis isolates were linezolid-resistant. The optrA carriage was the dominant mechanism in E. faecalis: 13 isolates, including 10 E. faecalis [70 % (7/10) linezolid-resistant and 30 % (3/10) linezolid-intermediate] and three E. faecium [33.3 % (1/3) linezolid-resistant and 66.7 % (2/3) linezolid-intermediate], contained the optrA gene. G2576T mutations in the 23S rRNA gene were detected only in E. faecium [14 isolates; 71.4 % (10/14) linezolid-resistant and 28.6 % (4/14) linezolid-intermediate]. One linezolid-intermediate E. faecium harboured a L22 protein alteration (Ser77Thr). No isolates contained cfr or cfr(B) genes and any L3 or L4 protein alterations. No genetic mechanism of resistance was identified for 67.6 % (23/34) of linezolid-resistant E. faecium. CONCLUSION A low rate of 23S rRNA mutations and the absence of known linezolid-resistance mechanisms in the majority of E. faecium isolates suggest regional differences in the mechanisms of linezolid resistance and the possibility of additional mechanisms.
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Affiliation(s)
- Sae-Mi Lee
- Departments of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Hee Jae Huh
- Departments of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Dong Joon Song
- Departments of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Hyang Jin Shim
- Center for Clinical Medicine, Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea
| | | | - Cheol-In Kang
- Division of Infectious Diseases, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Chang-Seok Ki
- Departments of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Nam Yong Lee
- Departments of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
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Bi R, Qin T, Fan W, Ma P, Gu B. The emerging problem of linezolid-resistant enterococci. J Glob Antimicrob Resist 2017; 13:11-19. [PMID: 29101082 DOI: 10.1016/j.jgar.2017.10.018] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 10/24/2017] [Accepted: 10/24/2017] [Indexed: 11/19/2022] Open
Abstract
Enterococcus is a significant pathogen in numerous infections, particularly in nosocomial infections, and is thus a great challenge to clinicians. Linezolid (LNZ), an oxazolidinone antibiotic, is an important therapeutic option for infections caused by Gram-positive bacterial pathogens, especially vancomycin-resistant enterococci. A systematic review was performed of the available literature on LNZ-resistant enterococci (LRE) to characterise these infections with respect to epidemiological, microbiological and clinical features. The results validated the potency of LNZ against enterococcal infections, with a sustained susceptibility rate of 99.8% in ZAAPS and 99.2% in LEADER surveillance programmes. Patients with LRE had been predominantly exposed to LNZ prior to isolation of LRE, with a mean treatment duration of 29.8±48.8days for Enterococcus faecalis and 23.1±21.4days for Enterococcus faecium. Paradoxically, LRE could also develop in patients without prior LNZ exposure. LNZ resistance was attributed to 23S rRNA (G2576T) mutations (51.2% of E. faecalis and 80.5% of E. faecium) as well as presence of the cfr gene (4.7% and 4.8%, respectively), which could transfer horizontally among the strains. In addition to the cfr gene, 32 cases of optrA-positive LRE were identified. Further study is required to determine the prevalence of novel resistance genes. The emergence of LRE thus hampers the treatment of such infections, which warrants worldwide surveillance.
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Affiliation(s)
- Ruru Bi
- Medical Technology School of Xuzhou Medical University, Xuzhou 221004, China
| | - Tingting Qin
- Medical Technology School of Xuzhou Medical University, Xuzhou 221004, China
| | - Wenting Fan
- Medical Technology School of Xuzhou Medical University, Xuzhou 221004, China
| | - Ping Ma
- Medical Technology School of Xuzhou Medical University, Xuzhou 221004, China; Department of Laboratory Medicine, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
| | - Bing Gu
- Medical Technology School of Xuzhou Medical University, Xuzhou 221004, China; Department of Laboratory Medicine, The Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
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Wilcox MH, Dmitrieva N, Gales AC, Petukhova I, Al-Obeid S, Rossi F, M Blondeau J. Susceptibility testing and reporting of new antibiotics with a focus on tedizolid: an international working group report. Future Microbiol 2017; 12:1523-1532. [PMID: 28812924 DOI: 10.2217/fmb-2017-0106] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Inappropriate use and overuse of antibiotics are among the most important factors in resistance development, and effective antibiotic stewardship measures are needed to optimize outcomes. Selection of appropriate antimicrobials relies on accurate and timely antimicrobial susceptibility testing. However, the availability of clinical breakpoints and in vitro susceptibility testing often lags behind regulatory approval by several years for new antimicrobials. A Working Group of clinical/medical microbiologists from Brazil, Canada, Mexico, Saudi Arabia, Russia and the UK recently examined issues surrounding antimicrobial susceptibility testing for novel antibiotics. While commercially available tests are being developed, potential surrogate antibiotics may be used as marker of susceptibility. Using tedizolid as an example of a new antibiotic, this special report makes recommendations to optimize routine susceptibility reporting.
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Affiliation(s)
- Mark H Wilcox
- Leeds Teaching Hospitals NHS Trust & University of Leeds, Leeds, UK
| | | | - Ana Cristina Gales
- Division of Infectious Diseases, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | | | - Suleiman Al-Obeid
- Microbiology Department, Security Forces Hospital, Riyadh, Saudi Arabia
| | - Flavia Rossi
- Hospital das Clínicas da Faculdade de Medicina, Seção de Microbiologia, Divisão de Laboratório Central LIM03, Universidade de São Paulo, São Paulo, Brazil
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