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Marco-Fuertes A, Marin C, Gimeno-Cardona C, Artal-Muñoz V, Vega S, Montoro-Dasi L. Multidrug-Resistant Commensal and Infection-Causing Staphylococcus spp. Isolated from Companion Animals in the Valencia Region. Vet Sci 2024; 11:54. [PMID: 38393072 PMCID: PMC10891909 DOI: 10.3390/vetsci11020054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/10/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
The emergence of antimicrobial resistance (AMR) and multidrug resistance (MDR) among microorganisms to commonly used antibiotics is a growing concern in both human and veterinary medicine. Companion animals play a significant role in the epidemiology of AMR, as their population is continuously increasing, posing a risk of disseminating AMR, particularly to strains of public health importance, such as methicillin-resistant Staphylococcus strains. Thus, this study aimed to investigate the prevalence of AMR and MDR in commensal and infection-causing Staphylococcus spp. in dogs and cats in Valencia region. For this purpose, 271 samples were taken from veterinary centers to assess antimicrobial susceptibility against 20 antibiotics, including some of the most important antibiotics for the treatment of Staphylococcus infections, including the five last resort antibiotics in this list. Of all the samples, 187 Staphylococcus spp. strains were recovered from asymptomatic and skin-diseased dogs and cats, of which S. pseudintermedius (≈60%) was more prevalent in dogs, while S. felis (≈50%) was more prevalent in cats. In the overall analysis of the isolates, AMR was observed for all antibiotics tested, including those crucial in human medicine. Furthermore, over 70% and 30% of the strains in dogs and cats, respectively, exhibited MDR. This study highlights the significance of monitoring the trends in AMR and MDR among companion animals. The potential contribution of these animals to the dissemination of AMR and its resistance genes to humans, other animals, and their shared environment underscores the necessity for adopting a One Health approach.
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Affiliation(s)
- Ana Marco-Fuertes
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Instituto de Ciencias Biomédicas, Universidad Cardenal Herrera-CEU, CEU Universities, Calle Santiago Ramón y Cajal 20, Alfara del Patriarca, 46115 Valencia, Spain; (A.M.-F.); (C.M.)
| | - Clara Marin
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Instituto de Ciencias Biomédicas, Universidad Cardenal Herrera-CEU, CEU Universities, Calle Santiago Ramón y Cajal 20, Alfara del Patriarca, 46115 Valencia, Spain; (A.M.-F.); (C.M.)
| | - Concepción Gimeno-Cardona
- Servicio de Microbiología, Consorcio Hospital General Universitario de Valencia, Facultad de Medicina, Universidad de Valencia, 46014 Valencia, Spain;
| | - Violeta Artal-Muñoz
- Servicio de Microbiología, Consorcio Hospital General Universitario de Valencia, 46014 Valencia, Spain;
| | - Santiago Vega
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Instituto de Ciencias Biomédicas, Universidad Cardenal Herrera-CEU, CEU Universities, Calle Santiago Ramón y Cajal 20, Alfara del Patriarca, 46115 Valencia, Spain; (A.M.-F.); (C.M.)
| | - Laura Montoro-Dasi
- Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Instituto de Ciencias Biomédicas, Universidad Cardenal Herrera-CEU, CEU Universities, Calle Santiago Ramón y Cajal 20, Alfara del Patriarca, 46115 Valencia, Spain; (A.M.-F.); (C.M.)
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Saldarriaga-Córdoba M, Irgang R, Avendaño-Herrera R. Comparison between genome sequences of Chilean Tenacibaculum dicentrarchi isolated from red conger eel (Genypterus chilensis) and Atlantic salmon (Salmo salar) focusing on bacterial virulence determinants. JOURNAL OF FISH DISEASES 2021; 44:1843-1860. [PMID: 34369594 DOI: 10.1111/jfd.13503] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/20/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
Tenacibaculum dicentrarchi is an emerging pathogen for salmonid cultures and red conger eel (Genypterus chilensis) in Chile, causing high economic losses not only in Chile but also to the global salmon industry. Infected fish show severe gross skin lesions that are sometimes accompanied by bone exposure. Despite pathogenicity demonstrated by Koch's postulates, no knowledge is currently available regarding the virulence machinery of T. dicentrarchi strains. Comparisons between the genome sequences of the eight T. dicentrarchi strains obtained from G. chilensis and Atlantic salmon (Salmo salar) provide insights on the existence of genomic diversity within this bacterium. The T. dicentrarchi type strain 3509T was used as a reference genome. Depending on the T. dicentrarchi strain, the discovered diversity included genes associated with iron acquisition mechanisms, copper homeostasis encoding, resistance to tetracycline and fluoroquinolones, pathogenic genomic islands and phages. Interestingly, genes encoding the T9SS membrane protein PorP/SprF were retrieved in all of the analysed T. dicentrarchi strains, regardless of the host fish (i.e. red conger eel or Atlantic salmon). However, the T6SS core component protein VgrG was identified in only one Atlantic salmon strain. Three types of peptidase genes and proteins associated with quorum sensing were detected in all of the T. dicentrarchi strains. In turn, all eight strains presented a total of 17 proteins associated with biofilm formation, which was previously confirmed through physiological studies. This comparative analysis will help elucidate and describe the genes and pathways that are likely involved in the virulence process of T. dicentrarchi. All or part of these predicted genes could aid the pathogen during the infective process in fish, making further physiological research necessary for clarification.
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Affiliation(s)
- Mónica Saldarriaga-Córdoba
- Centro de Investigación en Recursos Naturales y Sustentabilidad, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Rute Irgang
- Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Viña del Mar, Chile
- Centro FONDAP, Interdisciplinary Center for Aquaculture Research (INCAR), Universidad Andrés Bello, Viña del Mar, Chile
| | - Ruben Avendaño-Herrera
- Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Viña del Mar, Chile
- Centro FONDAP, Interdisciplinary Center for Aquaculture Research (INCAR), Universidad Andrés Bello, Viña del Mar, Chile
- Centro de Investigación Marina Quintay (CIMARQ), Universidad Andrés Bello, Quintay, Chile
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3
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Linezolid-resistant Staphylococcus capitis isolate. Infect Dis Now 2021; 52:176-177. [PMID: 34757234 DOI: 10.1016/j.idnow.2021.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 10/26/2021] [Indexed: 11/20/2022]
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França A, Gaio V, Lopes N, Melo LDR. Virulence Factors in Coagulase-Negative Staphylococci. Pathogens 2021; 10:170. [PMID: 33557202 PMCID: PMC7913919 DOI: 10.3390/pathogens10020170] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/29/2021] [Accepted: 01/29/2021] [Indexed: 12/13/2022] Open
Abstract
Coagulase-negative staphylococci (CoNS) have emerged as major pathogens in healthcare-associated facilities, being S. epidermidis, S. haemolyticus and, more recently, S. lugdunensis, the most clinically relevant species. Despite being less virulent than the well-studied pathogen S. aureus, the number of CoNS strains sequenced is constantly increasing and, with that, the number of virulence factors identified in those strains. In this regard, biofilm formation is considered the most important. Besides virulence factors, the presence of several antibiotic-resistance genes identified in CoNS is worrisome and makes treatment very challenging. In this review, we analyzed the different aspects involved in CoNS virulence and their impact on health and food.
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Affiliation(s)
- Angela França
- Laboratory of Research in Biofilms Rosário Oliveira, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; (V.G.); (N.L.)
| | | | | | - Luís D. R. Melo
- Laboratory of Research in Biofilms Rosário Oliveira, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; (V.G.); (N.L.)
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Kang HY, Moon DC, Mechesso AF, Choi JH, Kim SJ, Song HJ, Kim MH, Yoon SS, Lim SK. Emergence of cfr-Mediated Linezolid Resistance in Staphylococcus aureus Isolated from Pig Carcasses. Antibiotics (Basel) 2020; 9:E769. [PMID: 33147717 PMCID: PMC7692708 DOI: 10.3390/antibiotics9110769] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 12/20/2022] Open
Abstract
Altogether, 2547 Staphylococcus aureus isolated from cattle (n = 382), pig (n = 1077), and chicken carcasses (n = 1088) during 2010-2017 were investigated for linezolid resistance and were further characterized using molecular methods. We identified linezolid resistance in only 2.3% of pig carcass isolates. The linezolid-resistant (LR) isolates presented resistance to multiple antimicrobials, including chloramphenicol, clindamycin, and tiamulin. Molecular investigation exhibited no mutations in the 23S ribosomal RNA. Nevertheless, we found mutations in ribosomal proteins rplC (G121A) and rplD (C353T) in one and seven LR strains, respectively. All the LR isolates carried the multi-resistance gene cfr, and six of them co-carried the mecA gene. Additionally, all the LR isolates co-carried the phenicol exporter gene, fexA, and presented a high level of chloramphenicol resistance. LR S. aureus isolates represented 10 genotypes, including major genotypes ST433-t318, ST541-t034, ST5-t002, and ST9-t337. Staphylococcal enterotoxin and leukotoxin-encoding genes, alone or in combination, were detected in 68% of LR isolates. Isolates from different farms presented identical or different pulsed-field gel electrophoresis patterns. Collectively, toxigenic and LR S. aureus strains pose a crisis for public health. This study is the first to describe the mechanism of linezolid resistance in S. aureus isolated from food animal products in Korea.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Suk-Kyung Lim
- Bacterial Disease Division, Animal and Plant Quarantine Agency, 177 Hyeksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Korea; (H.Y.K.); (D.C.M.); (A.F.M.); (J.-H.C.); (S.-J.K.); (H.-J.S.); (M.H.K.); (S.-S.Y.)
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Nguyen LTT, Nguyen KNT, Le PNTA, Cafini F, Pascoe B, Sheppard SK, Nguyen TB, Nguyen TPH, Nguyen TV, Pham TTK, Morikawa K, Nguyen DQ, Duong HX. The emergence of plasmid-borne cfr-mediated linezolid resistant-staphylococci in Vietnam. J Glob Antimicrob Resist 2020; 22:462-465. [PMID: 32348904 DOI: 10.1016/j.jgar.2020.04.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 01/31/2020] [Accepted: 04/07/2020] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVES Linezolid is one of the last resort antibiotics effectively used in the treatment of infections caused by multidrug-resistant Gram-positive bacteria. Recent outbreaks of Linezolid resistance have been the great concern worldwide, while many countries have not experienced it. In this work, we aimed to evaluate the existence of linezolid resistance and further clarify potential resistance mechanism(s) in staphylococcal isolates obtained from the hospital in Vietnam, a country in which linezolid resistance had not been previously detected. METHODS Seventy staphylococcal clinical isolates including MRSA (n=63) and methicillin-resistant coagulase-negative staphylococci (MRCNS, n=7) were collected and analyzed for linezolid resistance. Linezolid-resistant isolates were submitted for whole genome sequencing to search for the resistance determinants. RESULTS We identified two coagulase-negative staphylococcal isolates that were resistant to linezolid. Whole genome sequencing revealed several alterations in the 23S rRNA and L3, L17, L22, L24, L30 ribosomal proteins. Importantly, both isolates harbour the chloramphenicol/florfenicol resistance (cfr) gene on a plasmid. The plasmid was closely identical to the pLRSA417 plasmid that was originally reported in China. CONCLUSIONS To the best of our knowledge, this is the first report of cfr-mediated linezolid resistance in clinically isolated staphylococci in Vietnam. We suggest that adequate surveillance is necessary to monitor the dissemination of linezolid resistance among staphylococcal species and other important pathogens.
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Affiliation(s)
| | | | | | - Fabio Cafini
- Universidad Europea de Madrid, Faculty of Biomedical and Health Sciences, Madrid, Spain
| | - Ben Pascoe
- Department of Biology and Biochemistry, The Milner Centre for Evolution, University of Bath, Bath, UK
| | - Samuel K Sheppard
- Department of Biology and Biochemistry, The Milner Centre for Evolution, University of Bath, Bath, UK
| | | | - Thien Phuc Hoang Nguyen
- Department of Genetics, Faculty of Biology and Biotechnology, University of Science, VNU-HCM, Viet Nam
| | - Thuy Vy Nguyen
- Department of Genetics, Faculty of Biology and Biotechnology, University of Science, VNU-HCM, Viet Nam
| | | | - Kazuya Morikawa
- Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Japan.
| | | | - Hoa Xo Duong
- Biotechnology Center of Ho Chi Minh City, Viet Nam
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Lazaris A, Coleman DC, Kearns AM, Pichon B, Kinnevey PM, Earls MR, Boyle B, O'Connell B, Brennan GI, Shore AC. Novel multiresistance cfr plasmids in linezolid-resistant methicillin-resistant Staphylococcus epidermidis and vancomycin-resistant Enterococcus faecium (VRE) from a hospital outbreak: co-location of cfr and optrA in VRE. J Antimicrob Chemother 2018; 72:3252-3257. [PMID: 28961986 DOI: 10.1093/jac/dkx292] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 07/19/2017] [Indexed: 11/14/2022] Open
Abstract
Background Linezolid is often the drug of last resort to treat infections caused by Gram-positive cocci. Linezolid resistance can be mutational (23S rRNA or L-protein) or, less commonly, acquired [predominantly cfr, conferring resistance to phenicols, lincosamides, oxazolidinones, pleuromutilins and streptogramin A compounds (PhLOPSA) or optrA, encoding oxazolidinone and phenicol resistance]. Objectives To investigate the clonality and genetic basis of linezolid resistance in 13 linezolid-resistant (LZDR) methicillin-resistant Staphylococcus epidermidis (MRSE) isolates recovered during a 2013/14 outbreak in an ICU in an Irish hospital and an LZDR vancomycin-resistant Enterococcus faecium (VRE) isolate from an LZDR-MRSE-positive patient. Methods All isolates underwent PhLOPSA susceptibility testing, 23S rRNA sequencing, DNA microarray profiling and WGS. Results All isolates exhibited the PhLOPSA phenotype. The VRE harboured cfr and optrA on a novel 73 kb plasmid (pEF12-0805) also encoding erm(A), erm(B), lnu(B), lnu(E), aphA3 and aadE. One MRSE (M13/0451, from the same patient as the VRE) harboured cfr on a novel 8.5 kb plasmid (pSEM13-0451). The remaining 12 MRSE lacked cfr but exhibited linezolid resistance-associated mutations and were closely related to (1-52 SNPs) but distinct from M13/0451 (202-223 SNPs). Conclusions Using WGS, novel and distinct cfr and cfr/optrA plasmids were identified in an MRSE and VRE isolate, respectively, as well as a cfr-negative LZDR-MRSE ICU outbreak and a distinct cfr-positive LZDR-MRSE from the same ICU. To our knowledge, this is the first report of cfr and optrA on a single VRE plasmid. Ongoing surveillance of linezolid resistance is essential to maintain its therapeutic efficacy.
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Affiliation(s)
- Alexandros Lazaris
- Microbiology Research Unit, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Dublin, Ireland
| | - David C Coleman
- Microbiology Research Unit, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Dublin, Ireland
| | - Angela M Kearns
- Antimicrobial Resistance and Healthcare Infections Reference Unit, National Infection Service, Public Health England, London, UK
| | - Bruno Pichon
- Antimicrobial Resistance and Healthcare Infections Reference Unit, National Infection Service, Public Health England, London, UK
| | - Peter M Kinnevey
- Microbiology Research Unit, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Dublin, Ireland
| | - Megan R Earls
- Microbiology Research Unit, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Dublin, Ireland
| | - Breida Boyle
- Department of Clinical Microbiology, School of Medicine, Trinity College Dublin, St James's Hospital, Dublin, Ireland
| | - Brian O'Connell
- Department of Clinical Microbiology, School of Medicine, Trinity College Dublin, St James's Hospital, Dublin, Ireland.,National MRSA Reference Laboratory, St James's Hospital, James's St, Dublin, Ireland
| | - Gráinne I Brennan
- National MRSA Reference Laboratory, St James's Hospital, James's St, Dublin, Ireland
| | - Anna C Shore
- Microbiology Research Unit, Dublin Dental University Hospital, University of Dublin, Trinity College Dublin, Dublin, Ireland
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Ferrández O, Urbina O, Grau S. Critical role of tedizolid in the treatment of acute bacterial skin and skin structure infections. DRUG DESIGN DEVELOPMENT AND THERAPY 2016; 11:65-82. [PMID: 28053508 PMCID: PMC5191846 DOI: 10.2147/dddt.s84667] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tedizolid phosphate has high activity against the Gram-positive microorganisms mainly involved in acute bacterial skin and skin structure infections, such as strains of Staphylococcus aureus (including methicillin-resistant S. aureus strains and methicillin-sensitive S. aureus strains), Streptococcus pyogenes, Streptococcus agalactiae, the Streptococcus anginosus group, and Enterococcus faecalis, including those with some mechanism of resistance limiting the use of linezolid. The area under the curve for time 0-24 hours/minimum inhibitory concentration (MIC) pharmacodynamic ratio has shown the best correlation with the efficacy of tedizolid, versus the time above MIC ratio and the maximum drug concentration/minimum inhibitory concentration ratio. Administration of this antibiotic for 6 days has shown its noninferiority versus administration of linezolid for 10 days in patients with skin and skin structure infections enrolled in two Phase III studies (ESTABLISH-1 and ESTABLISH-2). Tedizolid's more favorable safety profile and dosage regimen, which allow once-daily administration, versus linezolid, position it as a good therapeutic alternative. However, whether or not the greater economic cost associated with this antibiotic is offset by its shorter treatment duration and possibility of oral administration in routine clinical practice has yet to be clarified.
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Affiliation(s)
- Olivia Ferrández
- Hospital Pharmacy, Hospital Universitari del Mar, Barcelona, Spain; Nursing Department, Universitat Pompeu Fabra, Barcelona, Spain
| | - Olatz Urbina
- Hospital Pharmacy, Hospital Universitari del Mar, Barcelona, Spain
| | - Santiago Grau
- Hospital Pharmacy, Hospital Universitari del Mar, Barcelona, Spain; Medicine Department, Universitat Autònoma de Barcelona, Barcelona, Spain
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cfr-mediated linezolid-resistant clinical isolates of methicillin-resistant coagulase-negative staphylococci from China. J Glob Antimicrob Resist 2016; 8:1-5. [PMID: 27865985 DOI: 10.1016/j.jgar.2016.09.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 09/03/2016] [Accepted: 09/10/2016] [Indexed: 11/20/2022] Open
Abstract
Three linezolid-resistant coagulase-negative staphylococci (LR-CoNS), including two Staphylococcus cohnii and one Staphylococcus capitis, were isolated from 1104 clinical staphylococcal isolates across China in 2013-2014. Antibiotic susceptibilities of the bacteria were determined by the agar dilution method. PCR and DNA sequencing were performed to determine the potential molecular mechanism of linezolid resistance. The two linezolid-resistant S. cohnii isolates were subjected to pulsed-field gel electrophoresis (PFGE) to investigate their genetic relatedness. Primer walking, S1 nuclease PFGE and Southern blot hybridisation were conducted to ascertain the location and environment of the cfr gene. All three isolates were positive for the cfr gene. Amino acid mutations S158F and S158Y in the ribosomal protein L3 were identified in S. cohnii 13B289 and 13L105, respectively, both of which also had an additional substitution (D159Y) in L3. PFGE indicated that the two S. cohnii isolates belonged to diverse clonal strains. S1 nuclease PFGE and Southern blotting experiments indicated that the cfr gene of the three isolates resided on plasmids of similar size (ca. 35.4kb). The cfr-harbouring segments of S. capitis 13G350 and S. cohnii 13L105 were identical to plasmid pSS-01 reported previously. The cfr-carrying fragment of S. cohnii 13B289 was indistinguishable from the formerly described plasmid pSS-02. In conclusion, the presence of the cfr gene located on a plasmid was the main mechanism contributing to resistance to linezolid in the three staphylococcal isolates. Hence, timely detection and judicious use of antibiotics are essential to prevent further transmission of this resistance mechanism.
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Silva-Del Toro SL, Greenwood-Quaintance KE, Patel R. In vitro activity of tedizolid against linezolid-resistant staphylococci and enterococci. Diagn Microbiol Infect Dis 2016; 85:102-4. [PMID: 26971179 DOI: 10.1016/j.diagmicrobio.2016.02.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 02/05/2016] [Accepted: 02/07/2016] [Indexed: 10/22/2022]
Abstract
The tedizolid MIC of 27 clinical isolates of linezolid-resistant staphylococci and enterococci was determined. Tedizolid MICs were ≥1μg/mL and were 4- to 32-fold lower than those of linezolid. Linezolid resistance mechanisms included G2576T 23S rRNA gene and rplC and rplD mutations.
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Affiliation(s)
- Stephanie L Silva-Del Toro
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | | | - Robin Patel
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA; Division of Infectious Diseases, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
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Balandin B, Lobo B, Orden B, Román F, García E, Martínez R, Valdivia M, Ortega A, Fernández I, Galdos P. Emergence of linezolid-resistant coagulase-negative staphylococci in an intensive care unit. Infect Dis (Lond) 2015; 48:343-9. [PMID: 26670684 DOI: 10.3109/23744235.2015.1122225] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The aim of this study was to report the emergence of linezolid-resistant coagulase-negative staphylococci (CoNS) in an intensive care unit. METHODS An observational study was conducted in critically ill patients with colonization or infection by linezolid-resistant CoNS between January 2010 and December 2014. We analyzed the epidemiological and clinical features, and the mechanism of resistance to linezolid. We also evaluated the association between the incidence of linezolid-resistant CoNS strains and the consumption of linezolid in the study period. RESULTS During the study period 49 patients had a linezolid-resistant CoNS strain isolated from clinical samples (blood in 42 cases, urine in 6, peritoneal fluid in 1). Molecular study showed a combination of mechanisms of resistance. Most patients were critically ill (APACHE II score = 21.9 ± 8.3) and nearly all had undergone surgery and invasive procedures, and had prior exposure to antibiotics. Linezolid-resistant CoNS were considered to be contaminants in 42 patients and associated with infection in 7 patients, comprising bacteremia and septic shock in most of them. They were successfully treated with glycopeptides or daptomycin. A modest significant correlation was observed between the decrease in linezolid consumption and the lower incidence of resistant isolates. CONCLUSIONS Linezolid-resistant CoNS had emerged in critically ill patients with severe underlying diseases and prior antibiotic exposure. Most isolates represented colonization; however, linezolid-resistant CoNS can produce serious infections in critically ill patients. Glycopeptides and daptomycin seem to provide useful alternatives for therapy of these infections. A relationship was found between linezolid consumption and the incidence of linezolid-resistant CoNS strains.
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Affiliation(s)
- Bárbara Balandin
- a Intensive Care Unit , Hospital Universitario Puerta de Hierro Majadahonda , Madrid
| | - Beatriz Lobo
- a Intensive Care Unit , Hospital Universitario Puerta de Hierro Majadahonda , Madrid
| | - Beatriz Orden
- b Department of Microbiology , Hospital Universitario Puerta de Hierro Majadahonda , Madrid
| | - Federico Román
- c Laboratory of Nosocomial Infections , Centro Nacional de Microbiología, Instituto de Salud Carlos III , Madrid
| | - Elena García
- d Department of Hospitalary Pharmacy , Hospital Universitario Puerta de Hierro Majadahonda , Madrid , Spain
| | - Rocío Martínez
- b Department of Microbiology , Hospital Universitario Puerta de Hierro Majadahonda , Madrid
| | - Miguel Valdivia
- a Intensive Care Unit , Hospital Universitario Puerta de Hierro Majadahonda , Madrid
| | - Alfonso Ortega
- a Intensive Care Unit , Hospital Universitario Puerta de Hierro Majadahonda , Madrid
| | - Inmaculada Fernández
- a Intensive Care Unit , Hospital Universitario Puerta de Hierro Majadahonda , Madrid
| | - Pedro Galdos
- a Intensive Care Unit , Hospital Universitario Puerta de Hierro Majadahonda , Madrid
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Li S, Zhao L, Zheng B, Shen P, Ji J, Lv J, Li L, Xiao Y. Identification and characterization of cfr-positive Staphylococcus aureus isolates from community-onset infectious patients in a county hospital in China. J Med Microbiol 2015; 64:910-915. [PMID: 26066634 DOI: 10.1099/jmm.0.000096] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The cfr gene was detected in 14 meticillin-susceptible Staphylococcus aureus isolates recovered from outpatients with community-onset infections in a county hospital in China. The MIC of linezolid was 4 μg ml- 1 in eight isolates and 2 μg ml- 1 in six isolates. All isolates were susceptible to vancomycin and teicoplanin, but had elevated MICs for penicillin (0.5-128 μg ml- 1), chloramphenicol (2-32 μg ml- 1), clindamycin (0.5-128 μg ml- 1) and erythromycin (4-128 μg ml- 1). Nine isolates had mutations on domain V of 23S rRNA and/or the ribosomal L proteins that were not located close to the linezolid-binding pocket. Southern blotting experiments demonstrated that the cfr genes in all 14 isolates resided on plasmids. Sequence analysis of the 5.6 kb cfr-carrying plasmid segment revealed 99 % identity to the corresponding sequences in plasmid pSS-01 from animal staphylococci and plasmid pRM-01 from human staphylococci. Five isolates belonged to sequence type (ST)188 and three to ST965; the two ST types were previously reported in isolates of animal origin in some areas of China. These results indicate that the cfr-carrying plasmids in this study are likely of animal origin. The present study shows that cfr-harbouring S. aureus isolates have emerged in some areas of China and that cfr-carrying isolates may be transmitted between animals and humans.
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Affiliation(s)
- Sujuan Li
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, PR China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310003, PR China
| | - Lina Zhao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, PR China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310003, PR China
| | - Beiwen Zheng
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, PR China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310003, PR China
| | - Ping Shen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, PR China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310003, PR China
| | - Jinru Ji
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, PR China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310003, PR China
| | - Jifang Lv
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, PR China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310003, PR China
| | - Lanjuan Li
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, PR China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310003, PR China
| | - Yonghong Xiao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, PR China.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, 310003, PR China
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13
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Mutations in the bacterial ribosomal protein l3 and their association with antibiotic resistance. Antimicrob Agents Chemother 2015; 59:3518-28. [PMID: 25845869 DOI: 10.1128/aac.00179-15] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/31/2015] [Indexed: 11/20/2022] Open
Abstract
Different groups of antibiotics bind to the peptidyl transferase center (PTC) in the large subunit of the bacterial ribosome. Resistance to these groups of antibiotics has often been linked with mutations or methylations of the 23S rRNA. In recent years, there has been a rise in the number of studies where mutations have been found in the ribosomal protein L3 in bacterial strains resistant to PTC-targeting antibiotics but there is often no evidence that these mutations actually confer antibiotic resistance. In this study, a plasmid exchange system was used to replace plasmid-carried wild-type genes with mutated L3 genes in a chromosomal L3 deletion strain. In this way, the essential L3 gene is available for the bacteria while allowing replacement of the wild type with mutated L3 genes. This enables investigation of the effect of single mutations in Escherichia coli without a wild-type L3 background. Ten plasmid-carried mutated L3 genes were constructed, and their effect on growth and antibiotic susceptibility was investigated. Additionally, computational modeling of the impact of L3 mutations in E. coli was used to assess changes in 50S structure and antibiotic binding. All mutations are placed in the loops of L3 near the PTC. Growth data show that 9 of the 10 mutations were well accepted in E. coli, although some of them came with a fitness cost. Only one of the mutants exhibited reduced susceptibility to linezolid, while five exhibited reduced susceptibility to tiamulin.
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14
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Zhou W, Niu D, Cao X, Ning M, Zhang Z, Shen H, Zhang K. Clonal dissemination of linezolid-resistant Staphylococcus capitis with G2603T mutation in domain V of the 23S rRNA and the cfr gene at a tertiary care hospital in China. BMC Infect Dis 2015; 15:97. [PMID: 25888130 PMCID: PMC4352562 DOI: 10.1186/s12879-015-0841-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 02/18/2015] [Indexed: 11/22/2022] Open
Abstract
Background The present study aims to investigate the potential mechanism of linezolid-resistant Staphylococcus capitis (LRSC) isolates collected from our hospital. Methods The susceptibilities of 5 Staphylococcus capitis isolates displaying resistance towards linezolid were determined by E-test. Polymerase chain reactions (PCRs) and DNA sequencing were used to investigate the potential molecular mechanism. Clonal relatedness between these strains was analyzed by pulsed-field gel electrophoresis (PFGE). Results The MICs of linezolid on these 5 isolates were >256 μg/mL. The G2603T mutation was observed in the domain V of the 23S rRNA with cfr gene being also widely detected among these 5 strains. PFGE analysis displayed close genetic relatedness between these linezolid-resistant isolates. Conclusions The emergence of LRSC isolates carrying G2603T mutation in the domain V of the 23S rRNA and harboring cfr gene in our hospital may pose a potential challenge to the public health.
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Affiliation(s)
- Wanqing Zhou
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, the affiliated Hospital of Nanjing University Medical School, 321# Zhongshan Road, Gulou District, Nanjing, Jiangsu Province, 210008, PR China.
| | - Dongmei Niu
- Department of Laboratory Medicine, Nanjing Jinling Hospital, the affiliated Hospital of Nanjing University Medical School, 305# East Zhongshan Road, Baixia District, Nanjing, Jiangsu Province, 210002, PR China.
| | - Xiaoli Cao
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, the affiliated Hospital of Nanjing University Medical School, 321# Zhongshan Road, Gulou District, Nanjing, Jiangsu Province, 210008, PR China.
| | - Mingzhe Ning
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, the affiliated Hospital of Nanjing University Medical School, 321# Zhongshan Road, Gulou District, Nanjing, Jiangsu Province, 210008, PR China.
| | - Zhifeng Zhang
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, the affiliated Hospital of Nanjing University Medical School, 321# Zhongshan Road, Gulou District, Nanjing, Jiangsu Province, 210008, PR China.
| | - Han Shen
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, the affiliated Hospital of Nanjing University Medical School, 321# Zhongshan Road, Gulou District, Nanjing, Jiangsu Province, 210008, PR China.
| | - Kui Zhang
- Department of Laboratory Medicine, Nanjing Drum Tower Hospital, the affiliated Hospital of Nanjing University Medical School, 321# Zhongshan Road, Gulou District, Nanjing, Jiangsu Province, 210008, PR China.
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15
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Sahm DF, Deane J, Bien PA, Locke JB, Zuill DE, Shaw KJ, Bartizal KF. Results of the Surveillance of Tedizolid Activity and Resistance Program: in vitro susceptibility of Gram-positive pathogens collected in 2011 and 2012 from the United States and Europe. Diagn Microbiol Infect Dis 2015; 81:112-8. [DOI: 10.1016/j.diagmicrobio.2014.08.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 08/22/2014] [Accepted: 08/23/2014] [Indexed: 10/24/2022]
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16
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Linezolid-resistant Staphylococcus haemolyticus and Staphylococcus hominis: single and double mutations at the domain V of 23S rRNA among isolates from a Rio de Janeiro hospital. Diagn Microbiol Infect Dis 2014; 80:307-10. [PMID: 25294302 DOI: 10.1016/j.diagmicrobio.2014.09.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 08/19/2014] [Accepted: 09/12/2014] [Indexed: 11/21/2022]
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17
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Mendes RE, Deshpande LM, Jones RN. Linezolid update: stable in vitro activity following more than a decade of clinical use and summary of associated resistance mechanisms. Drug Resist Updat 2014; 17:1-12. [PMID: 24880801 DOI: 10.1016/j.drup.2014.04.002] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Linezolid, approved for clinical use since 2000, has become an important addition to the anti-Gram-positive infection armamentarium. This oxazolidinone drug has in vitro and in vivo activity against essentially all Gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The in vitro activity of linezolid was well documented prior to its clinical application, and several ongoing surveillance studies demonstrated consistent and potent results during the subsequent years of clinical use. Emergence of resistance has been limited and associated with invasive procedures, deep organ involvement, presence of foreign material and mainly prolonged therapy. Non-susceptible organisms usually demonstrate alterations in the 23S rRNA target, which remain the main resistance mechanism observed in enterococci; although a few reports have described the detection of cfr-mediated resistance in Enterococcus faecalis. S. aureus isolates non-susceptible to linezolid remain rare in large surveillance studies. Most isolates harbour 23S rRNA mutations; however, cfr-carrying MRSA isolates have been observed in the United States and elsewhere. It is still uncertain whether the occurrences of such isolates are becoming more prevalent. Coagulase-negative isolates (CoNS) resistant to linezolid were uncommon following clinical approval. Surveillance data have indicated that CoNS isolates, mainly Staphylococcus epidermidis, currently account for the majority of Gram-positive organisms displaying elevated MIC results to linezolid. In addition, these isolates frequently demonstrate complex and numerous resistance mechanisms, such as alterations in the ribosomal proteins L3 and/or L4 and/or presence of cfr and/or modifications in 23S rRNA. The knowledge acquired during the past decades on this initially used oxazolidinone has been utilized for developing new candidate agents, such as tedizolid and radezolid, and as linezolid patents soon begin to expire, generic brands will certainly become available. These events will likely establish a new chapter for this successful class of antimicrobial agents.
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Affiliation(s)
| | | | - Ronald N Jones
- JMI Laboratories, North Liberty, IA 52317, USA; Tufts University School of Medicine, Boston, MA 02111, USA
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18
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Characterization and monitoring of linezolid-resistant clinical isolates of Staphylococcus epidermidis in an intensive care unit 4 years after an outbreak of infection by cfr-mediated linezolid-resistant Staphylococcus aureus. Diagn Microbiol Infect Dis 2013; 76:325-9. [DOI: 10.1016/j.diagmicrobio.2013.04.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 03/28/2013] [Accepted: 04/09/2013] [Indexed: 11/24/2022]
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19
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Linezolid resistance in Brazilian Staphylococcus hominis strains is associated with L3 and 23S rRNA ribosomal mutations. Antimicrob Agents Chemother 2013; 57:4082-3. [PMID: 23689714 DOI: 10.1128/aac.00437-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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20
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Cui L, Wang Y, Li Y, He T, Schwarz S, Ding Y, Shen J, Lv Y. Cfr-mediated linezolid-resistance among methicillin-resistant coagulase-negative staphylococci from infections of humans. PLoS One 2013; 8:e57096. [PMID: 23437319 PMCID: PMC3577776 DOI: 10.1371/journal.pone.0057096] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 01/17/2013] [Indexed: 12/24/2022] Open
Abstract
Four methicillin-resistant coagulase-negative staphylococci (MRCoNS), one Staphylococcus haemolyticus and three Staphylococcus cohnii, from infections of humans collected via the Ministry of Health National Antimicrobial Resistance Surveillance Net (Mohnarin) program in China were identified as linezolid-resistant. These four isolates were negative for the 23S rRNA mutations, but positive for the gene cfr. Mutations in the gene for the ribosomal protein L3, which resulted in the amino acid exchanges Gly152Asp and Tyr158Phe, were identified in S. haemolyticus 09D279 and S. cohnii NDM113, respectively. In each isolate, the cfr gene was located on a plasmid of ca. 35.4 kb, as shown by S1 nuclease pulsed-field gel electrophoresis and Southern blotting experiments. This plasmid was indistinguishable from the previously described plasmid pSS-02 by its size, restriction pattern, and a sequenced 14-kb cfr-carrying segment. Plasmid pSS-02 was originally identified in staphylococci isolated from pigs. This is the first time that a cfr-carrying plasmid has been detected in MRCoNS obtained from intensive care patients in China. Based on the similarities to the cfr-carrying plasmid pSS-02 from porcine coagulase-negative staphylococci, a transmission of this cfr-carrying plasmid between staphylococci from pigs and humans appears to be likely.
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Affiliation(s)
- Lanqing Cui
- Institute of Clinical Pharmacology, Peking University First Hospital, Peking University, Beijing, People's Republic of China
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21
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The genetic environment of the cfr gene and the presence of other mechanisms account for the very high linezolid resistance of Staphylococcus epidermidis isolate 426-3147L. Antimicrob Agents Chemother 2012; 57:1173-9. [PMID: 23254434 DOI: 10.1128/aac.02047-12] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The clinical Staphylococcus epidermidis isolate 426-3147L exhibits an unusually high resistance to linezolid that exceeds 256 μg/ml. The presence of the cfr gene, encoding the RNA methyltransferase targeting an rRNA nucleotide located in the linezolid binding site, accounts for a significant fraction of resistance. The association of cfr with a multicopy plasmid is one of the factors that contribute to its elevated expression. Mapping of the cfr transcription start sites identified the native cfr promoter. Furthermore, analysis of the cfr transcripts in Staphylococcus epidermidis 426-3147L showed that some of them originate from the upstream plasmid-derived promoters whose activity contributes to efficient cfr transcription. The genetic environment of the cfr gene and its idiosyncratic transcription pattern result in increased activity of Cfr methyltransferase, leading to a high fraction of the ribosomes being methylated at A2503 of the 23S rRNA. Curing of the Staphylococcus epidermidis 426-3147L isolate from the cfr-containing plasmid reduced the linezolid MIC to 64 μg/ml, indicating that other determinants contribute to resistance. Nucleotide sequence analysis revealed the presence of the C2534T mutation in two of the six 23S rRNA gene alleles as well as the presence of mutations in the genes of ribosomal proteins L3 and L4, which were previously implicated in linezolid resistance. Thus, the combination of resistance mechanisms operating through alteration of the drug target site appears to cause an unusually high level of linezolid resistance in the isolate.
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22
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Lin G, Pankuch GA, Appelbaum PC, Kosowska-Shick K. Activity of telavancin compared to other agents against coagulase-negative staphylococci with different resistotypes by time kill. Diagn Microbiol Infect Dis 2012; 73:287-9. [DOI: 10.1016/j.diagmicrobio.2012.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 03/24/2012] [Accepted: 04/08/2012] [Indexed: 10/28/2022]
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23
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Molecular epidemiology of Staphylococcus epidermidis clinical isolates from U.S. hospitals. Antimicrob Agents Chemother 2012; 56:4656-61. [PMID: 22687512 DOI: 10.1128/aac.00279-12] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The epidemiology of Staphylococcus epidermidis in U.S. hospitals remains limited. This study aimed to address the genetic backgrounds of linezolid-susceptible and -resistant S. epidermidis strains (isolated in 2010), including cfr-carrying strains. In addition, the antimicrobial susceptibility profiles and linezolid resistance mechanisms among clonal lineages were assessed. A total of 71 S. epidermidis isolates were selected, and linezolid-resistant strains were screened for cfr and mutations in 23S rRNA, L3, and L4. All isolates were subjected to multilocus sequence typing (MLST), and the results were analyzed by eBURST. Overall, 27 sequence types (STs) were detected, and ST5 (21.1%) and ST2 (16.9%) predominated. The majority (62/71; 87.3%) of STs belonged to clonal complex 2 (CC2), which was mostly comprised of subclusters CC2-II (41/62; 66.1%) and CC2-I (21/62; 33.9%). Other STs were grouped within CC23 or CC32 or were singletons. CC2-I strains were more likely to display a methicillin (95.2% versus 33.3 to 70.7%), a linezolid (47.6% versus 0.0 to 7.3%), or a multidrug (81.0% versus 33.3 to 36.6%) resistance phenotype. Among linezolid-resistant isolates, cfr was noted only within CC2 strains, and it was detected equally in the CC2-I (3/10; 30.0%) and CC2-II (1/3; 33.3%) subclusters. 23S rRNA mutations (G2576 [seven strains] and C2534 [one strain]) were observed only among CC2-I (8/10; 80.0%) isolates. Strains showing a G2576 alteration also had M156 (7/7; 100.0%) and/or H146 (6/7; 85.7%) L3 modifications. This study provides an overview of the S. epidermidis clonal distribution and reports higher resistance rates among CC2-I strains. The results show that cfr may be acquired and expressed by both CC2 main subclusters, while 23S rRNA mutations appeared more often within CC2-I strains. Interestingly, these 23S rRNA mutants also had L3 alterations, which may act synergistically or in a compensatory manner to minimize the fitness cost while providing survival advantages under selective pressure.
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24
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Long KS, Vester B. Resistance to linezolid caused by modifications at its binding site on the ribosome. Antimicrob Agents Chemother 2012; 56:603-12. [PMID: 22143525 PMCID: PMC3264260 DOI: 10.1128/aac.05702-11] [Citation(s) in RCA: 243] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Linezolid is an oxazolidinone antibiotic in clinical use for the treatment of serious infections of resistant Gram-positive bacteria. It inhibits protein synthesis by binding to the peptidyl transferase center on the ribosome. Almost all known resistance mechanisms involve small alterations to the linezolid binding site, so this review will therefore focus on the various changes that can adversely affect drug binding and confer resistance. High-resolution structures of linezolid bound to the 50S ribosomal subunit show that it binds in a deep cleft that is surrounded by 23S rRNA nucleotides. Mutation of 23S rRNA has for some time been established as a linezolid resistance mechanism. Although ribosomal proteins L3 and L4 are located further away from the bound drug, mutations in specific regions of these proteins are increasingly being associated with linezolid resistance. However, very little evidence has been presented to confirm this. Furthermore, recent findings on the Cfr methyltransferase underscore the modification of 23S rRNA as a highly effective and transferable form of linezolid resistance. On a positive note, detailed knowledge of the linezolid binding site has facilitated the design of a new generation of oxazolidinones that show improved properties against the known resistance mechanisms.
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Affiliation(s)
- Katherine S. Long
- Department of Systems Biology and Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Birte Vester
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
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