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Keikha M, Karbalaei M. Global distribution of heterogeneous vancomycin-intermediate Staphylococcus aureus strains (1997-2021): a systematic review and meta-analysis. J Glob Antimicrob Resist 2024; 37:11-21. [PMID: 38336227 DOI: 10.1016/j.jgar.2024.02.002] [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: 04/06/2023] [Revised: 02/01/2024] [Accepted: 02/02/2024] [Indexed: 02/12/2024] Open
Abstract
BACKGROUND Heterogeneous vancomycin-intermediate Staphylococcus aureus is considered one of the main causes in treatment failure of vancomycin, which leads to poor clinical outcomes. Herein, we comprehensively evaluated characteristics such as global prevalence, trend, and genetic backgrounds of these strains. METHODS In this study, we conducted a meta-analysis based on PRISMA checklist 2020. In the beginning, global databases were searched to achieve the studies related to the prevalence of hVISA in clinical isolates of methicillin-resistant Staphylococcus aureus. After retrieving the eligible English studies, the prevalence of hVISA isolates and their trend changes were assessed using event rate with 95% confidence intervals. RESULTS In the present study, the prevalence of 114 801 MRSA isolates (of 124 studies) was 64%. According to our results, although the frequency of infection with hVISA is increasing in recent years, there is not a significant difference between Asian countries and Europe/America (6.1% vs. 6.8%). In addition, infection with hVISA bacteria was higher in bacteraemic patients than other infections (9.4% vs. 5.5%), which increases hospitalization, treatment costs, and mortality in these patients. Isolates harbouring SCCmec types II and III are most common genotypes in hVISA strains. CONCLUSIONS The prevalence of hVISA is increasing, which will reduce the effectiveness of vancomycin treatment in the coming years. The presence of hVISA stains in blood samples was higher than the other samples, which is threatening for bacteraemic patients. The results of the current study indicate a universal program to identify and control the spread of such strains in nosocomial infections.
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Affiliation(s)
- Masoud Keikha
- Department of Microbiology and Virology, School of Medicine, Iranshahr University of Medical Sciences, Iranshahr, Iran
| | - Mohsen Karbalaei
- Department of Microbiology and Virology, School of Medicine, Jiroft University of Medical Sciences, Jiroft, Iran; Bio Environmental Health Hazards Research Center, Jiroft University of Medical Sciences, Jiroft, Iran.
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2
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Tran NN, Morrisette T, Jorgensen SCJ, Orench-Benvenutti JM, Kebriaei R. Current therapies and challenges for the treatment of Staphylococcus aureus biofilm-related infections. Pharmacotherapy 2023; 43:816-832. [PMID: 37133439 DOI: 10.1002/phar.2806] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 03/10/2023] [Accepted: 03/16/2023] [Indexed: 05/04/2023]
Abstract
Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and contributes to significant increase in morbidity and mortality especially when associated with medical devices and in biofilm form. Biofilm structure provides a pathway for the enrichment of resistant and persistent phenotypes of S. aureus leading to relapse and recurrence of infection. Minimal diffusion of antibiotics inside biofilm structure leads to heterogeneity and distinct physiological activity. Additionally, horizontal gene transfer between cells in proximity adds to the challenges associated with eradication of biofilms. This narrative review focuses on biofilm-associated infections caused by S. aureus, the impact of environmental conditions on biofilm formation, interactions inside biofilm communities, and the clinical challenges that they present. Conclusively, potential solutions, novel treatment strategies, combination therapies, and reported alternatives are discussed.
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Affiliation(s)
- Nikki N Tran
- Department of Pharmacy, The Ohio State University Wexner Medical Center - The James Cancer Hospital and Solove Research Institute, Columbus, Ohio, USA
| | - Taylor Morrisette
- Department of Clinical Pharmacy and Outcomes Sciences, Medical University of South Carolina College of Pharmacy, Charleston, South Carolina, USA
- Department of Pharmacy Services, Medical University of South Carolina Shawn Jenkins Children's Hospital, Charleston, South Carolina, USA
| | - Sarah C J Jorgensen
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - José M Orench-Benvenutti
- P3 Research Laboratory, Division of Outcomes and Translational Sciences, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
| | - Razieh Kebriaei
- P3 Research Laboratory, Division of Outcomes and Translational Sciences, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
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3
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Parsons JB, Westgeest AC, Conlon BP, Fowler VG. Persistent Methicillin-Resistant Staphylococcus aureus Bacteremia: Host, Pathogen, and Treatment. Antibiotics (Basel) 2023; 12:455. [PMID: 36978320 PMCID: PMC10044482 DOI: 10.3390/antibiotics12030455] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/18/2023] [Accepted: 02/20/2023] [Indexed: 03/02/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a devastating pathogen responsible for a variety of life-threatening infections. A distinctive characteristic of this pathogen is its ability to persist in the bloodstream for several days despite seemingly appropriate antibiotics. Persistent MRSA bacteremia is common and is associated with poor clinical outcomes. The etiology of persistent MRSA bacteremia is a result of the complex interplay between the host, the pathogen, and the antibiotic used to treat the infection. In this review, we explore the factors related to each component of the host-pathogen interaction and discuss the clinical relevance of each element. Next, we discuss the treatment options and diagnostic approaches for the management of persistent MRSA bacteremia.
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Affiliation(s)
- Joshua B. Parsons
- Department of Medicine, Division of Infectious Disease, Duke University Medical Center, Durham, NC 27710, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Annette C. Westgeest
- Department of Medicine, Division of Infectious Disease, Duke University Medical Center, Durham, NC 27710, USA
- Department of Infectious Diseases, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Brian P. Conlon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Vance G. Fowler
- Department of Medicine, Division of Infectious Disease, Duke University Medical Center, Durham, NC 27710, USA
- Duke Clinical Research Institute, Durham, NC 27710, USA
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4
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Wongthong S, Taron W, Chanawong A, Tippayawat P, Pongdontri P, Srisrattakarn A, Panpru P, Lulitanond A. Effect of Vancomycin on Cellular Fatty Acid Profiles of Vancomycin-Susceptible and Nonsusceptible Staphylococcus aureus. Microb Drug Resist 2021; 28:267-273. [PMID: 34748415 DOI: 10.1089/mdr.2021.0055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Vancomycin is widely used for treatment of infection caused by methicillin-resistant Staphylococcus aureus (MRSA) leading to an increasing appearance of low-level vancomycin-resistant isolates called heterogeneous vancomycin-intermediate S. aureus (hVISA). The mechanism of vancomycin tolerance in hVISA is still unclear. This study aimed to investigate the fatty acid compositions of S. aureus isolates under the stress environment with vancomycin. The different responses of hVISA and vancomycin-susceptible S. aureus (VSSA) may lead to more understanding the mechanism. The bacterial lipid profiles were tested three times from three extractions of each isolate cultured on tryptic soy agar (TSA) and TSA with vancomycin. Of the 30 MRSA isolates studied, 13, 12, and 5 isolates were VSSA, hVISA, and VISA, respectively. The analysis of bacterial lipid profiles showed that under vancomycin stress, there was a reduction of straight chain fatty acids (SCFAs) in VSSA isolates but an increase in branched chain fatty acids (BCFAs). In contrast, the hVISA group exhibited an increase only in the BCFAs but not in SCFAs. Of interest, vancomycin had no effect on either BCFAs or SCFAs of the VISA cells. This study provided information of bacterial adaptation during stress with vancomycin that may be helpful to overcome the resistant bacteria.
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Affiliation(s)
- Sujintana Wongthong
- Department of Clinical Microbiology and Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.,Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.,Faculty of Medical Technology, Nakhon Ratchasima College, Nakhon Ratchasima, Thailand
| | - Wichit Taron
- Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Aroonwadee Chanawong
- Department of Clinical Microbiology and Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.,Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Patcharaporn Tippayawat
- Department of Clinical Microbiology and Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.,Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Paweena Pongdontri
- Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
| | - Arpasiri Srisrattakarn
- Department of Clinical Microbiology and Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.,Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Pimchanok Panpru
- Department of Clinical Microbiology and Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.,Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Aroonlug Lulitanond
- Department of Clinical Microbiology and Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.,Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
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5
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Shariati A, Dadashi M, Moghadam MT, van Belkum A, Yaslianifard S, Darban-Sarokhalil D. Global prevalence and distribution of vancomycin resistant, vancomycin intermediate and heterogeneously vancomycin intermediate Staphylococcus aureus clinical isolates: a systematic review and meta-analysis. Sci Rep 2020; 10:12689. [PMID: 32728110 PMCID: PMC7391782 DOI: 10.1038/s41598-020-69058-z] [Citation(s) in RCA: 134] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 06/15/2020] [Indexed: 12/22/2022] Open
Abstract
Vancomycin-resistant Staphylococcus aureus (VRSA), Vancomycin-intermediate S. aureus (VISA) and heterogeneous VISA (hVISA) are subject to vancomycin treatment failure. The aim of the present study was to determine their precise prevalence and investigate prevalence variability depending on different years and locations. Several international databases including Medline (PubMed), Embase and Web of Sciences were searched (data from 1997 to 2019) to identify studies that addressed the prevalence of VRSA, VISA and hVISA among human clinical isolates around the world. Subgroup analyses and meta-regression were conducted to indicate potential source of variation. Publication bias was assessed using Egger's test. Statistical analyses were conducted using STATA software (version 14.0). Data analysis showed that VRSA, VISA and hVISA isolates were reported in 23, 50 and 82 studies, with an overall prevalence of 1.5% among 5855 S. aureus isolates, 1.7% among 22,277 strains and 4.6% among 47,721 strains, respectively. The overall prevalence of VRSA, VISA, and hVISA before 2010 was 1.2%, 1.2%, and 4%, respectively, while their prevalence after this year has reached 2.4%, 4.3%, and 5.3%. The results of this study showed that the frequency of VRSA, VISA and hVISA after 2010 represent a 2.0, 3.6 and 1.3-fold increase over prior years. In a subgroup analysis of different strain origins, the highest frequency of VRSA (3.6%) and hVISA (5.2%) was encountered in the USA while VISA (2.1%) was more prevalent in Asia. Meta-regression analysis showed significant increasing of VISA prevalence in recent years (p value ≤ 0.05). Based on the results of case reports (which were not included in the calculations mentioned above), the numbers of VRSA, VISA and hVISA isolates were 12, 24 and 14, respectively, among different continents. Since the prevalence of VRSA, VISA and hVISA has been increasing in recent years (especially in the Asian and American continents), rigorous monitoring of vancomycin treatment, it's the therapeutic response and the definition of appropriate control guidelines depending on geographical regions is highly recommended and essential to prevent the further spread of vancomycin-resistant S. aureus.
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Affiliation(s)
- Aref Shariati
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Student Research Committee, Iran University of Medical Sciences, Tehran, Iran
| | - Masoud Dadashi
- Department of Microbiology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran.
- Non Communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran.
| | - Majid Taati Moghadam
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Student Research Committee, Iran University of Medical Sciences, Tehran, Iran
| | - Alex van Belkum
- Open Innovation and Partnerships, Route de Port Michaud, 38390, La Balme Les Grottes, France
| | - Somayeh Yaslianifard
- Department of Microbiology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
| | - Davood Darban-Sarokhalil
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
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6
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Wang HY, Chen CH, Lee TY, Horng JT, Liu TP, Tseng YJ, Lu JJ. Rapid Detection of Heterogeneous Vancomycin-Intermediate Staphylococcus aureus Based on Matrix-Assisted Laser Desorption Ionization Time-of-Flight: Using a Machine Learning Approach and Unbiased Validation. Front Microbiol 2018; 9:2393. [PMID: 30364336 PMCID: PMC6193097 DOI: 10.3389/fmicb.2018.02393] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 09/18/2018] [Indexed: 11/13/2022] Open
Abstract
Heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) is an emerging superbug with implicit drug resistance to vancomycin. Detecting hVISA can guide the correct administration of antibiotics. However, hVISA cannot be detected in most clinical microbiology laboratories because the required diagnostic tools are either expensive, time consuming, or labor intensive. By contrast, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) is a cost-effective and rapid tool that has potential for providing antibiotics resistance information. To analyze complex MALDI-TOF mass spectra, machine learning (ML) algorithms can be used to generate robust hVISA detection models. In this study, MALDI-TOF mass spectra were obtained from 35 hVISA/vancomycin-intermediate S. aureus (VISA) and 90 vancomycin-susceptible S. aureus isolates. The vancomycin susceptibility of the isolates was determined using an Etest and modified population analysis profile–area under the curve. ML algorithms, namely a decision tree, k-nearest neighbors, random forest, and a support vector machine (SVM), were trained and validated using nested cross-validation to provide unbiased validation results. The area under the curve of the models ranged from 0.67 to 0.79, and the SVM-derived model outperformed those of the other algorithms. The peaks at m/z 1132, 2895, 3176, and 6591 were noted as informative peaks for detecting hVISA/VISA. We demonstrated that hVISA/VISA could be detected by analyzing MALDI-TOF mass spectra using ML. Moreover, the results are particularly robust due to a strict validation method. The ML models in this study can provide rapid and accurate reports regarding hVISA/VISA and thus guide the correct administration of antibiotics in treatment of S. aureus infection.
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Affiliation(s)
- Hsin-Yao Wang
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.,Ph.D. Program in Biomedical Engineering, Chang Gung University, Taoyuan, Taiwan
| | - Chun-Hsien Chen
- Department of Information Management, Chang Gung University, Taoyuan, Taiwan
| | - Tzong-Yi Lee
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.,Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, Taiwan.,Innovation Center for Big Data and Digital Convergence, Yuan Ze University, Taoyuan, Taiwan.,Warshel Institute for Computational Biology, Chinese University of Hong Kong, Shenzhen, China.,School of Science and Engineering, Chinese University of Hong Kong, Shenzhen, China
| | - Jorng-Tzong Horng
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.,Department of Bioinformatics and Medical Engineering, Asia University, Taichung, Taiwan.,Department of Computer Science and Information Engineering, National Central University, Taoyuan, Taiwan
| | - Tsui-Ping Liu
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Yi-Ju Tseng
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.,Department of Information Management, Chang Gung University, Taoyuan, Taiwan
| | - Jang-Jih Lu
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.,School of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan
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7
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Yang CC, Sy CL, Huang YC, Shie SS, Shu JC, Hsieh PH, Hsiao CH, Chen CJ. Risk factors of treatment failure and 30-day mortality in patients with bacteremia due to MRSA with reduced vancomycin susceptibility. Sci Rep 2018; 8:7868. [PMID: 29777150 PMCID: PMC5959888 DOI: 10.1038/s41598-018-26277-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 05/09/2018] [Indexed: 02/02/2023] Open
Abstract
Bacteremia caused by MRSA with reduced vancomycin susceptibility (MRSA-RVS) frequently resulted in treatment failure and mortality. The relation of bacterial factors and unfavorable outcomes remains controversial. We retrospectively reviewed clinical data of patients with bacteremia caused by MRSA with vancomycin MIC = 2 mg/L from 2009 to 2012. The significance of bacterial genotypes, agr function and heterogeneous vancomycin-intermediate S. aureus (hIVSA) phenotype in predicting outcomes were determined after clinical covariates adjustment with multivariate analysis. A total of 147 patients with mean age of 63.5 (±18.1) years were included. Seventy-nine (53.7%) patients failed treatment. Forty-seven (31.9%) patients died within 30 days of onset of MRSA bacteremia. The Charlson index, Pitt bacteremia score and definitive antibiotic regimen were independent factors significantly associated with either treatment failure or mortality. The hVISA phenotype was a potential risk factor predicting treatment failure (adjusted odds ratio 2.420, 95% confidence interval 0.946–6.191, P = 0.0652). No bacterial factors were significantly associated with 30-day mortality. In conclusion, the comorbidities, disease severity and antibiotic regimen remained the most relevant factors predicting treatment failure and 30-day mortality in patients with MRSA-RVS bacteremia. hIVSA phenotype was the only bacterial factor potentially associated with unfavorable outcome in this cohort.
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Affiliation(s)
- Chien-Chang Yang
- College of Medicine, Chang Gung University, 333, Taoyuan, Taiwan.,Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital, 333, Taoyuan, Taiwan
| | - Cheng-Len Sy
- Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Yhu-Chering Huang
- College of Medicine, Chang Gung University, 333, Taoyuan, Taiwan.,Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, 333, Taoyuan, Taiwan
| | - Shian-Sen Shie
- College of Medicine, Chang Gung University, 333, Taoyuan, Taiwan.,Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital, 333, Taoyuan, Taiwan
| | - Jwu-Ching Shu
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, 333, Taoyuan, Taiwan
| | - Pang-Hsin Hsieh
- College of Medicine, Chang Gung University, 333, Taoyuan, Taiwan.,Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, 333, Taoyuan, Taiwan
| | - Ching-Hsi Hsiao
- College of Medicine, Chang Gung University, 333, Taoyuan, Taiwan.,Department of Ophthalmology, Chang Gung Memorial Hospital, 333, Taoyuan, Taiwan
| | - Chih-Jung Chen
- College of Medicine, Chang Gung University, 333, Taoyuan, Taiwan. .,Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, 333, Taoyuan, Taiwan.
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8
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Asakura K, Azechi T, Sasano H, Matsui H, Hanaki H, Miyazaki M, Takata T, Sekine M, Takaku T, Ochiai T, Komatsu N, Shibayama K, Katayama Y, Yahara K. Rapid and easy detection of low-level resistance to vancomycin in methicillin-resistant Staphylococcus aureus by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. PLoS One 2018. [PMID: 29522576 PMCID: PMC5844673 DOI: 10.1371/journal.pone.0194212] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Vancomycin-intermediately resistant Staphylococcus aureus (VISA) and heterogeneous VISA (hVISA) are associated with treatment failure. hVISA contains only a subpopulation of cells with increased minimal inhibitory concentrations, and its detection is problematic because it is classified as vancomycin-susceptible by standard susceptibility testing and the gold-standard method for its detection is impractical in clinical microbiology laboratories. Recently, a research group developed a machine-learning classifier to distinguish VISA and hVISA from vancomycin-susceptible S. aureus (VSSA) according to matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) data. Nonetheless, the sensitivity of hVISA classification was found to be 76%, and the program was not completely automated with a graphical user interface. Here, we developed a more accurate machine-learning classifier for discrimination of hVISA from VSSA and VISA among MRSA isolates in Japanese hospitals by means of MALDI-TOF MS data. The classifier showed 99% sensitivity of hVISA classification. Furthermore, we clarified the procedures for preparing samples and obtaining MALDI-TOF MS data and developed all-in-one software, hVISA Classifier, with a graphical user interface that automates the classification and is easy for medical workers to use; it is publicly available at https://github.com/bioprojects/hVISAclassifier. This system is useful and practical for screening MRSA isolates for the hVISA phenotype in clinical microbiology laboratories and thus should improve treatment of MRSA infections.
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Affiliation(s)
- Kota Asakura
- Department of Pharmacy, Juntendo University Hospital, Tokyo, Japan
| | - Takuya Azechi
- Department of Pharmacy, Juntendo University Hospital, Tokyo, Japan
| | - Hiroshi Sasano
- Department of Pharmacy, Juntendo University Hospital, Tokyo, Japan
| | - Hidehito Matsui
- Infection Control Research Center, Kitasato Institute for Life Science, Kitasato University, Tokyo, Japan
| | - Hideaki Hanaki
- Infection Control Research Center, Kitasato Institute for Life Science, Kitasato University, Tokyo, Japan
| | - Motoyasu Miyazaki
- Department of Pharmacy, Fukuoka University Chikushi Hospital, Fukuoka, Japan
| | - Tohru Takata
- Department of Infection Control, Fukuoka University Hospital, Fukuoka, Japan
| | - Miwa Sekine
- Department of Microbiology, Faculty of Medicine, Juntendo University, Tokyo, Japan
| | - Tomoiku Takaku
- Division of Hematology, Department of Internal Medicine, Juntendo University, Tokyo, Japan
| | - Tomonori Ochiai
- Division of Hematology, Department of Internal Medicine, Juntendo University, Tokyo, Japan
| | - Norio Komatsu
- Division of Hematology, Department of Internal Medicine, Juntendo University, Tokyo, Japan
| | - Keigo Shibayama
- Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo, Japan
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yuki Katayama
- Department of Microbiology, Faculty of Medicine, Juntendo University, Tokyo, Japan
- * E-mail: (KY); (YK)
| | - Koji Yahara
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Tokyo, Japan
- * E-mail: (KY); (YK)
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9
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Koh YR, Kim KH, Chang CL, Yi J. Prevalence and Clinical Impact of Heterogeneous Vancomycin-Intermediate Staphylococcus aureus Isolated From Hospitalized Patients. Ann Lab Med 2017; 36:235-43. [PMID: 26915612 PMCID: PMC4773264 DOI: 10.3343/alm.2016.36.3.235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 02/10/2016] [Accepted: 02/11/2016] [Indexed: 01/23/2023] Open
Abstract
Background We estimated the prevalence and clinical impact of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA). The concordance between macromethod and glycopeptide resistance detection (GRD) E tests was determined. In addition, predictors of clinical outcomes in hospitalized patients with S. aureus bacteremia (SAB) or pneumonia (SAP) were evaluated. Methods We obtained 229 consecutive S. aureus isolates from all hospitalized patients at two university hospitals located in Busan and Yangsan, Korea. Standard, macromethod, and GRD E tests were performed. Additionally, we reviewed the medical records of all patients. Among the 229 patients, predictors of clinical outcomes were analyzed for 107 patients with SAB and 39 with SAP. Results Among the 229 isolates, 34.5% of S. aureus isolates and 50.7% of methicillin-resistant S. aureus isolates exhibited the hVISA phenotype based on the macromethod E test. hVISA was nearly associated with treatment failure in patients with SAB (P=0.054) and was significantly associated with treatment failure in patients with SAP (P=0.014). However, hVISA was not associated with 30-day mortality in patients with SAB or SAP. The concordance between the macromethod and GRD E tests was 84.2%. Conclusions hVISA is quite common in the southeastern part of Korea. hVISA is associated with treatment failure in patients with SAP.
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Affiliation(s)
- Young Rae Koh
- Department of Laboratory Medicine, Pusan National University School of Medicine, Busan, Korea
| | - Kye Hyung Kim
- Department of Internal Medicine, Pusan National University Hospital, Busan, Korea
| | - Chulhun L Chang
- Department of Laboratory Medicine, Pusan National University School of Medicine, Busan, Korea
| | - Jongyoun Yi
- Department of Laboratory Medicine, Pusan National University School of Medicine, Busan, Korea.,Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea.,Biomedical Research Institute, Pusan National University Hospital, Busan, Korea.
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10
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Impact of Time to Appropriate Therapy on Mortality in Patients with Vancomycin-Intermediate Staphylococcus aureus Infection. Antimicrob Agents Chemother 2016; 60:5546-53. [PMID: 27401565 DOI: 10.1128/aac.00925-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 07/01/2016] [Indexed: 12/29/2022] Open
Abstract
Despite the increasing incidence of vancomycin-intermediate Staphylococcus aureus (VISA) infections, few studies have examined the impact of delay in receipt of appropriate antimicrobial therapy on outcomes in VISA patients. We examined the effects of timing of appropriate antimicrobial therapy in a cohort of patients with sterile-site methicillin-resistant S. aureus (MRSA) and VISA infections. In this single-center, retrospective cohort study, we identified all patients with MRSA or VISA sterile-site infections from June 2009 to February 2015. Clinical outcomes were compared according to MRSA/VISA classification, demographics, comorbidities, and antimicrobial treatment. Thirty-day all-cause mortality was modeled with Kaplan-Meier curves. Multivariate logistic regression analysis (MVLRA) was used to determine odds ratios for mortality. We identified 354 patients with MRSA (n = 267) or VISA (n = 87) sterile-site infection. Fifty-five patients (15.5%) were nonsurvivors. Factors associated with mortality in MVLRA included pneumonia, unknown source of infection, acute physiology and chronic health evaluation (APACHE) II score, solid-organ malignancy, and admission from skilled care facilities. Time to appropriate antimicrobial therapy was not significantly associated with outcome. Presence of a VISA infection compared to that of a non-VISA S. aureus infection did not result in excess mortality. Linezolid use was a risk for mortality in patients with APACHE II scores of ≥14. Our results suggest that empirical vancomycin use in patients with VISA infections does not result in excess mortality. Future studies should (i) include larger numbers of patients with VISA infections to confirm the findings presented here and (ii) determine the optimal antibiotic therapy for critically ill patients with MRSA and VISA infections.
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11
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Vancomycin MIC Does Not Predict 90-Day Mortality, Readmission, or Recurrence in a Prospective Cohort of Adults with Staphylococcus aureus Bacteremia. Antimicrob Agents Chemother 2016; 60:5276-84. [PMID: 27324762 DOI: 10.1128/aac.00658-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 06/11/2016] [Indexed: 12/29/2022] Open
Abstract
Staphylococcus aureus bacteremia (SAB) is a tremendous health burden. Previous studies examining the association of vancomycin MIC and outcomes in patients with SAB have been inconclusive. This study evaluated the association between vancomycin MICs and 30- or 90-day mortality in individuals with SAB. This was a prospective cohort study of adults presenting from 2008 to 2013 with a first episode of SAB. Subjects were identified by an infection surveillance system. The main predictor was vancomycin MIC by MicroScan. The primary outcomes were death at 30 and 90 days, and secondary outcomes included recurrence, readmission, or a composite of death, recurrence, and readmission at 30 and 90 days. Covariates included methicillin susceptibility, demographics, illness severity, comorbidities, infectious source, and antibiotic use. Cox proportional-hazards models with propensity score adjustment were used to estimate 30- and 90-day outcomes. Of 429 unique first episodes of SAB, 11 were excluded, leaving 418 individuals for analysis. Eighty-three (19.9%) participants had a vancomycin MIC of 2 μg/ml. In the propensity-adjusted Cox model, a vancomycin MIC of 2 μg/ml compared to <2 μg/ml was not associated with a greater hazard of mortality or composite outcome of mortality, readmission, and recurrence at either 30 days (hazard ratios [HRs] of 0.86 [95% confidence interval {CI}, 0.41, 1.80] [P = 0.70] and 0.94 [95% CI, 0.55, 1.58] [P = 0.80], respectively) or 90 days (HRs of 0.91 [95% CI, 0.49, 1.69] [P = 0.77] and 0.69 [95% CI, 0.46, 1.04] [P = 0.08], respectively) after SAB diagnosis. In a prospective cohort of patients with SAB, vancomycin MIC was not associated with 30- or 90-day mortality or a composite of mortality, disease recurrence, or hospital readmission.
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12
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Rapid Detection of Vancomycin-Intermediate Staphylococcus aureus by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry. J Clin Microbiol 2016; 54:883-90. [PMID: 26763961 DOI: 10.1128/jcm.02428-15] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 01/04/2016] [Indexed: 12/16/2022] Open
Abstract
Vancomycin is the standard of care for the treatment of invasive methicillin-resistantStaphylococcus aureus(MRSA) infections. Infections with vancomycin-nonsusceptible MRSA, including vancomycin-intermediateS. aureus(VISA) and heterogeneous VISA (hVISA), are clinically challenging and are associated with poor patient outcomes. The identification of VISA in the clinical laboratory depends on standard susceptibility testing, which takes at least 24 h to complete after isolate subculture, whereas hVISA is not routinely detected in clinical labs. We therefore sought to determine whether VISA and hVISA can be differentiated from vancomycin-susceptibleS. aureus(VSSA) using the spectra produced by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Strains of MRSA were characterized for vancomycin susceptibility phenotype by broth microdilution and modified population analysis. We tested 21 VISA, 21 hVISA, and 38 VSSA isolates by MALDI-TOF MS. Susceptibility phenotypes were separated by using a support vector machine (SVM) machine learning algorithm. The resulting model was validated by leave-one-out cross validation. Models were developed and validated by using spectral profiles generated under various subculture conditions, as well as with and without hVISA strains. Using SVM, we correctly identified 100% of the VISA and 97% of the VSSA isolates with an overall classification accuracy of 98%. Addition of hVISA to the model resulted in 76% hVISA identification, 100% VISA identification, and 89% VSSA identification, for an overall classification accuracy of 89%. We conclude that VISA/hVISA and VSSA isolates are separable by MALDI-TOF MS with SVM analysis.
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Sirichoat A, Wongthong S, Kanyota R, Tavichakorntrakool R, Chanawong A, Welbat JU, Lulitanond A. Phenotypic Characteristics of Vancomycin-Non-Susceptible Staphylococcus aureus. Jundishapur J Microbiol 2016; 9:e26069. [PMID: 27099678 PMCID: PMC4834129 DOI: 10.5812/jjm.26069] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 10/05/2015] [Accepted: 10/16/2015] [Indexed: 11/16/2022] Open
Abstract
Background: Staphylococcus aureus, with reduced vancomycin susceptibility, is probably under the regulation of several genes and various express phenotypes. Objectives: This study aimed to investigate the phenotypic differences between vancomycin-susceptible S. aureus (VSSA), vancomycin-intermediate S. aureus (VISA), and heterogeneous VISA (hVISA) isolates. Materials and Methods: A total of 130 methicillin-resistant S. aureus (MRSA) isolates were studied, including 49 VSSA, 28 hVISA, and 5 VISA isolates from blood cultures and 48 isolates (two VSSA, six hVISA, and 40 VISA) derived in vitro (laboratory-induced/sub-passaged). Their phenotypes were examined using a coagulase tube test, colony spreading on soft agar, and urease activity. The SCCmec and agr typing were performed using multiplex PCR. Results: Most of the MRSA isolates were SCCmec III-agr I (84.5%), followed by SCCmec II-agr II (11.8%). The average plasma coagulation time of vancomycin-non-susceptible isolates was longer than that of the susceptible isolates (12 vs. 2.6 hours). Four hVISA (P = 0.023) and nine VISA (P < 0.001) isolates yielded a negative coagulase test after 24-hour incubation. The percentage of VSSA isolates showing non-spreading colonies (accessory gene regulator (agr) dysfunction) was significantly lower than in the VISA group (P = 0.013), but no significant difference was found between VSSA and hVISA. The VISA group showed higher urease activity than that of the VSSA and hVISA groups (P = 0.002). Conclusions: There were diverse phenotypic changes among vancomycin-non-susceptible S. aureus isolates. This may be due to the variety of related regulatory systems. The diversity of phenotypic expression may result in its misidentification in routine laboratory checks.
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Affiliation(s)
- Auttawit Sirichoat
- Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Sujintana Wongthong
- Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Ratdawan Kanyota
- Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Ratree Tavichakorntrakool
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Aroonwadee Chanawong
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Jariya Umka Welbat
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Aroonlug Lulitanond
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
- Corresponding author: Aroonlug Lulitanond, Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand. Tel/Fax: +66-43202086, E-mail:
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Sequential Evolution of Vancomycin-Intermediate Resistance Alters Virulence in Staphylococcus aureus: Pharmacokinetic/Pharmacodynamic Targets for Vancomycin Exposure. Antimicrob Agents Chemother 2015; 60:1584-91. [PMID: 26711763 DOI: 10.1128/aac.02657-15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 12/13/2015] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus possesses exceptional virulence and a remarkable ability to adapt in the face of antibiotic therapy. We examined the in vitro evolution of S. aureus in response to escalating vancomycin exposure by evaluating bacterial killing and the progression of resistance. A hollow-fiber infection model was utilized to simulate human doses of vancomycin increasing from 0.5 to 4 g every 12 h (q12h) versus a high inoculum (10(8) CFU/ml) of methicillin-resistant S. aureus (MRSA) USA300 and USA400. Host-pathogen interactions using Galleria mellonella and accessory gene regulator (agr) expression were studied in serially obtained isolates. In both USA300 and USA400 MRSA isolates, vancomycin exposure up to 2 g q12h resulted in persistence and regrowth, whereas 4 g administered q12h achieved sustained killing against both strains. As vancomycin exposure increased from 0.5 to 2 g q12h, the bacterial population shifted toward vancomycin-intermediate resistance, and collateral increases in the MICs of daptomycin and televancin were observed over 10 days. Guideline-recommended exposure of a ratio of the area under the concentration-time curve for the free, unbound fraction of the drug to the MIC (fAUC/MIC ratio) of 200 displayed a 0.344-log bacterial reduction in area, whereas fAUC/MICs of 371 and 554 were needed to achieve 1.00- and 2.00-log reductions in area, respectively. The stepwise increase in resistance paralleled a decrease in G. mellonella mortality (P = 0.021) and a gradual decline of RNAIII expression over 10 days. Currently recommended doses of vancomycin resulted in amplification of resistance and collateral damage to other antibiotics. Decreases in agr expression and virulence during therapy may be an adaptive mechanism of S. aureus persistence.
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15
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Clinical and Molecular Characterization of Invasive Heteroresistant Vancomycin-Intermediate Staphylococcus aureus Infections in Korean Hospitals. J Clin Microbiol 2015; 54:760-3. [PMID: 26677256 DOI: 10.1128/jcm.02595-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 12/10/2015] [Indexed: 11/20/2022] Open
Abstract
Invasive heteroresistant vancomycin-intermediate Staphylococcus aureus (h-VISA) isolates were identified and characterized in 10 Korean hospitals from July 2009 to June 2011. The prevalence of h-VISA infections was 3.3% (42/1,289). Most (41/42) were health care-associated infections caused by strains belonging to sequence type 5. Cases of persistent bacteremia were frequent (17/42), and 30-day mortality was high (16/40).
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16
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Hu HC, Kao KC, Chiu LC, Chang CH, Hung CY, Li LF, Liu TP, Lin LC, Chen NH, Huang CC, Yang CT, Lu JJ. Clinical outcomes and molecular typing of heterogenous vancomycin-intermediate Staphylococcus aureus bacteremia in patients in intensive care units. BMC Infect Dis 2015; 15:444. [PMID: 26497595 PMCID: PMC4619030 DOI: 10.1186/s12879-015-1215-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 10/14/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Staphylococcus aureus is one of most common pathogens in humans. Methicillin-resistant S. aureus (MRSA) accounts for 64 % of S. aureus bacteremia isolated in intensive care units (ICUs), and heteroresistant vancomycin-intermediates S. aureus (hVISA) is a phenotype of MRSA. However, studies focusing on the hVISA impact on critically ill patients are scarce. METHODS This was a retrospective study conducted in a tertiary medical center from January 2009 to December 2010. All adult patients in ICUs with MRSA bloodstream infection were eligible. A modified population analysis profile and area under the curve method was applied to all isolates to confirm hVISA phenotype. Multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) and the accessory gene regulator (agr) typing were performed individually. Clinical outcomes including in-hospital mortality, length of stay in intensive care unit and hospital after MRSA bacteremia of the patients were also analyzed. RESULTS A total of 48 patients were enrolled and 14 patients were confirmed to have the hVISA phenotype. The prevalence of hVISA was 29.2 %. There was no difference in the age, sex, comorbidity, Charlson's comorbidity score and previous vancomycin therapy between the hVISA and VSSA groups. The hVISA group had a significantly higher in-hospital mortality than the VSSA group (13/14 versus 22/34; p = 0.046). All of the 14 hVISA patients had an MIC = 2 mg/L by E-test and this represented a significant association between high MIC and the development of hVISA (p < 0.001). MLST analysis showed all the isolates in the hVISA group were ST239, while ST239 (14/34; 41.2 %) and ST5 (12/34; 35.3 %) were predominant in the VSSA group (p = 0.007). A comparison of the survivor and non-survivor group showed that the hVISA phenotype (OR 11.8; 95 % CI 1.1-126.99; p = 0.042) and sequential organ failure assessment (SOFA) score (OR 1.39; 95 % CI 1.07-1.81; p = 0.014) were independent factors significantly associated with in-hospital mortality. CONCLUSIONS Patients in ICUs with MRSA bacteremia may have a higher in-hospital mortality if they have the hVISA phenotype. SOFA score is also predictor of mortality.
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Affiliation(s)
- Han-Chung Hu
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan. .,Department of Respiratory Therapy, Chang Gung University, College of Medicine, Taoyuan, Taiwan. .,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
| | - Kuo-Chin Kao
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan. .,Department of Respiratory Therapy, Chang Gung University, College of Medicine, Taoyuan, Taiwan. .,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
| | - Li-Chung Chiu
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan. .,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
| | - Chih-Hao Chang
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan. .,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
| | - Chen-Yiu Hung
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan. .,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
| | - Li-Fu Li
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan. .,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
| | - Tsui-Ping Liu
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at LinKou, 5, Fu-Shin St., Kwei-Shan, Taoyuan, 333, Taiwan.
| | - Lee-Chung Lin
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at LinKou, 5, Fu-Shin St., Kwei-Shan, Taoyuan, 333, Taiwan.
| | - Ning-Hung Chen
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan. .,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
| | - Chung-Chi Huang
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan. .,Department of Respiratory Therapy, Chang Gung University, College of Medicine, Taoyuan, Taiwan. .,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
| | - Cheng-Ta Yang
- Department of Respiratory Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan. .,Department of Respiratory Therapy, Chang Gung University, College of Medicine, Taoyuan, Taiwan. .,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan.
| | - Jang-Jih Lu
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at LinKou, 5, Fu-Shin St., Kwei-Shan, Taoyuan, 333, Taiwan. .,Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan.
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17
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Methicillin-Resistant Staphylococcus aureus Grown on Vancomycin-Supplemented Screening Agar Displays Enhanced Biofilm Formation. Antimicrob Agents Chemother 2015; 59:7906-10. [PMID: 26459889 DOI: 10.1128/aac.00568-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 09/30/2015] [Indexed: 11/20/2022] Open
Abstract
Brain heart infusion agar containing 3 mg/liter vancomycin (BHI-V3) was used to screen for heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA). There was markedly greater biofilm formation by isolates that grew on BHI-V3 than by strains that did not grow on BHI-V3. Increased biofilm formation by hVISA may be mediated by FnbA- and polysaccharide intercellular adhesin-dependent pathways, and upregulation of atlA and sarA may also contribute to enhanced biofilm formation by hVISA upon prolonged exposure to vancomycin.
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18
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Zhang S, Sun X, Chang W, Dai Y, Ma X. Systematic Review and Meta-Analysis of the Epidemiology of Vancomycin-Intermediate and Heterogeneous Vancomycin-Intermediate Staphylococcus aureus Isolates. PLoS One 2015; 10:e0136082. [PMID: 26287490 PMCID: PMC4546009 DOI: 10.1371/journal.pone.0136082] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 07/29/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Vancomycin-intermediate Staphylococcus aureus (VISA) and heterogeneous VISA (hVISA) are associated with vancomycin treatment failure, and are becoming an increasing public health problem. Therefore, we undertook this study of 91 published studies and made subgroup comparisons of hVISA/VISA incidence in different study years, locations, and types of clinical samples. We also analyzed the genetic backgrounds of these strains. METHODS A systematic literature review of relevant articles published in PubMed and EMBASE from January 1997 to August 2014 was conducted. We selected and assessed journal articles reporting the prevalence rates of hVISA/VISA. RESULTS The pooled prevalence of hVISA was 6.05% in 99,042 methicillin-resistant S. aureus (MRSA) strains and that of VISA was 3.01% in 68,792 MRSA strains. The prevalence of hVISA was 4.68% before 2006, 5.38% in 2006-2009, and 7.01% in 2010-2014. VISA prevalence was 2.05%, 2.63%, and 7.93%, respectively. In a subgroup analysis of different isolation locations, the prevalence of hVISA strains was 6.81% in Asia and 5.60% in Europe/America, and that of VISA was 3.42% and 2.75%, respectively. The frequencies of hVISA isolated from blood culture samples and from all clinical samples were 9.81% and 4.68%, respectively, and those of VISA were 2.00% and 3.07%, respectively. The most prevalent genotype was staphylococcal cassette chromosome mec (SCCmec) II, which accounted for 48.16% and 37.74% of hVISA and VISA, respectively. Sequence Type (ST) 239 was most prevalent. CONCLUSION The prevalence of hVISA/VISA has been increasing in recent years, but has been grossly underestimated. Its incidence is higher in Asia than in Europe/America. hVISA is isolated from blood culture samples more often than from other samples. These strains are highly prevalent in epidemic MRSA strains. This study clarifies the epidemiology of hVISA/VISA and indicates that the detection of these strains and the control of nosocomial infections must be strengthened.
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Affiliation(s)
- Shanshan Zhang
- School of Medicine, Shandong University, Ji’nan, 250061, PR China
| | - Xiaoxi Sun
- Department of Clinical Laboratory, Affiliated Provincial Hospital of Anhui Medical University, Hefei, 230001, PR China
| | - Wenjiao Chang
- Department of Clinical Laboratory, Affiliated Provincial Hospital of Anhui Medical University, Hefei, 230001, PR China
| | - Yuanyuan Dai
- Department of Clinical Laboratory, Affiliated Provincial Hospital of Anhui Medical University, Hefei, 230001, PR China
| | - Xiaoling Ma
- Department of Clinical Laboratory, Affiliated Provincial Hospital of Anhui Medical University, Hefei, 230001, PR China
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19
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Vas KE, Török Á, Cordoş B, Vancea S, Brassai A, Székely E. Effect of teicoplanin on Staphylococcus aureus with heterointermediate susceptibility to glycopeptides in experimental infective endocarditis model. J Chemother 2015; 28:446-9. [PMID: 25976829 DOI: 10.1179/1973947815y.0000000031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Affiliation(s)
- Krisztina E Vas
- a University of Medicine and Pharmacy Târgu-Mures, Microbiology Department , Targu Mures, Mures County , Romania
| | - Árpád Török
- b University of Medicine and Pharmacy Târgu-Mureş, Surgery Department , Targu Mures, Mures County , Romania
| | - Bogdan Cordoş
- c University of Medicine and Pharmacy Târgu-Mureş , Experimental Station , Targu Mures, Mures County , Romania
| | - Szende Vancea
- d University of Medicine and Pharmacy Târgu-Mureş, Department of Physical Chemistry , Targu Mures, Mures County , Romania
| | - Attila Brassai
- e University of Medicine and Pharmacy Târgu-Mureş, Pharmacology Department , Targu Mures, Mures County , Romania
| | - Edit Székely
- a University of Medicine and Pharmacy Târgu-Mures, Microbiology Department , Targu Mures, Mures County , Romania.,f Târgu-Mureş Clinical Emergency Hospital , Central Laboratory , Targu Mures, Mures County , Romania
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20
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Mirza HC, Sancak B, Gür D. The Prevalence of Vancomycin-Intermediate Staphylococcus aureus and Heterogeneous VISA Among Methicillin-Resistant Strains Isolated from Pediatric Population in a Turkish University Hospital. Microb Drug Resist 2015; 21:537-44. [PMID: 25919019 DOI: 10.1089/mdr.2015.0048] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
There are limited data regarding the prevalence of vancomycin-intermediate Staphylococcus aureus (VISA)/heterogeneous VISA (hVISA) among pediatric population. Our objective was to determine the distribution of vancomycin and daptomycin minimum inhibitory concentrations (MICs) and explore the phenomenon of vancomycin MIC creep and the VISA/hVISA prevalence among the methicillin-resistant Staphylococcus aureus (MRSA) strains belonging to pediatric population by population analysis profile-area under the curve (PAP-AUC) and Etest macromethod. Vancomycin and daptomycin susceptibilities of 94 pediatric isolates of MRSA were tested by broth microdilution (BMD) and Etest methods. To determine the prevalence of VISA/hVISA, Etest macromethod and PAP-AUC was performed on all isolates. All isolates were susceptible to vancomycin and daptomycin by both BMD and Etest methods. Twenty-eight (29.8%) isolates had vancomycin MICs of 2 μg/ml by BMD. No increase in vancomycin MICs was observed over time. There were no VISA among 94 MRSA tested but 20 (21.3%) hVISA isolates were identified by PAP-AUC. Results of Etest macromethod were compared to PAP-AUC. Etest macromethod was 60.0% sensitive and 90.5% specific. The hVISA isolates represented 53.6% of isolates with vancomycin MICs of 2 μg/ml. Also, 75% of hVISA isolates had vancomycin MICs of 2 μg/ml. To our knowledge, this is the first study investigating the prevalence of VISA/hVISA among MRSA isolated from pediatric patients by PAP-AUC method. Based on our findings, MRSA isolates, which have vancomycin MIC of 2 μg/ml can be investigated for the presence of hVISA. In this study, daptomycin showed potent activity against all isolates and may represent a therapeutic option for MRSA infections.
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Affiliation(s)
- Hasan Cenk Mirza
- 1 Department of Medical Microbiology, Merzifon State Hospital , Amasya, Turkey
| | - Banu Sancak
- 2 Department of Medical Microbiology, Hacettepe University Medical School , Ankara, Turkey
| | - Deniz Gür
- 2 Department of Medical Microbiology, Hacettepe University Medical School , Ankara, Turkey
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21
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Gomes DM, Ward KE, LaPlante KL. Clinical implications of vancomycin heteroresistant and intermediately susceptible Staphylococcus aureus. Pharmacotherapy 2015; 35:424-32. [PMID: 25884530 DOI: 10.1002/phar.1577] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Staphylococcus aureus (S. aureus) has proven to be a major pathogen with the emergence of methicillin-resistant S. aureus (MRSA) infections and recently with heteroresistant vancomycin-intermediate S. aureus (hVISA) and vancomycin-intermediate S. aureus (VISA) infections. Although vancomycin is traditionally a first-line and relatively effective antibiotic, its continued use is under question because reports of heteroresistance in S. aureus isolates are increasing. Both hVISA and VISA infections are associated with complicated clinical courses and treatment failures. The prevalence, mechanism of resistance, clinical significance, and laboratory detection of hVISA and VISA infections are not conclusive, making it difficult to apply research findings to clinical situations. We provide an evidence-based review of S. aureus isolates expressing heterogenic and reduced susceptibility to vancomycin.
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Affiliation(s)
- Diane M Gomes
- Department of Pharmacy Practice, University of Rhode Island, Kingston, Rhode Island; Veterans Affairs Medical Center, Providence, Rhode Island
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22
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Cázares-Domínguez V, Cruz-Córdova A, Ochoa SA, Escalona G, Arellano-Galindo J, Rodríguez-Leviz A, Hernández-Castro R, López-Villegas EO, Xicohtencatl-Cortes J. Vancomycin tolerant, methicillin-resistant Staphylococcus aureus reveals the effects of vancomycin on cell wall thickening. PLoS One 2015; 10:e0118791. [PMID: 25793280 PMCID: PMC4368777 DOI: 10.1371/journal.pone.0118791] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 01/06/2015] [Indexed: 11/18/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is an important opportunistic pathogen that causes both healthcare- and community-acquired infections. An increase in the incidence of these infections may lead to a substantial change in the rate of vancomycin usage. Incidence of reduced susceptibility to vancomycin has been increasing worldwide for the last few years, conferring different levels of resistance to vancomycin as well as producing changes in the cell wall structure. The aim of the present study was to determine the effect of vancomycin on cell wall thickening in clinical isolates of vancomycin-tolerant (VT) MRSA obtained from pediatric patients. From a collection of 100 MRSA clinical isolates from pediatric patients, 12% (12/100) were characterized as VT-MRSA, and from them, 41.66% (5/12) exhibited the heterogeneous vancomycin-intermediate S. aureus (hVISA) phenotype. Multiplex-PCR assays revealed 66.66% (8/12), 25% (3/12), and 8.33% (1/12) of the VT-MRSA isolates were associated with agr group II, I, and III polymorphisms, respectively; the II-mec gene was amplified from 83.3% (10/12) of the isolates, and the mecIVa gene was amplified from 16.66% (2/12) of the isolates. Pulsed field electrophoresis (PFGE) fingerprint analysis showed 62% similarity among the VT-MRSA isolates. Thin transverse sections analyzed by transmission electron microscopy (TEM) revealed an average increase of 24 nm (105.55%) in the cell wall thickness of VT-MRSA compared with untreated VT-MRSA isolates. In summary, these data revealed that the thickened cell walls of VT-MRSA clinical isolates with agr type II and SCCmec group II polymorphisms are associated with an adaptive resistance to vancomycin.
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Affiliation(s)
- Vicenta Cázares-Domínguez
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Delegación Cuauhtémoc, México D.F., México
| | - Ariadnna Cruz-Córdova
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Delegación Cuauhtémoc, México D.F., México
| | - Sara A. Ochoa
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Delegación Cuauhtémoc, México D.F., México
| | - Gerardo Escalona
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Delegación Cuauhtémoc, México D.F., México
| | - José Arellano-Galindo
- Departamento de Infectología, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Delegación Cuauhtémoc, México D.F., México
| | - Alejandra Rodríguez-Leviz
- Laboratorio de Patología, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Delegación Cuauhtémoc, México D.F., México
| | - Rigoberto Hernández-Castro
- Departamento de Ecología de Agentes Patógenos. Hospital General “Dr. Manuel Gea González”, Delegación Tlalpan, México D.F., México
| | - Edgar O. López-Villegas
- Laboratorio Central de Microscopia. Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional. Prol. De Carpio y Plan de Ayala S/N Col. Santo Tomás, Delegación Miguel Hidalgo, México D.F., México
| | - Juan Xicohtencatl-Cortes
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Dr. Márquez 162, Col. Doctores, Delegación Cuauhtémoc, México D.F., México
- * E-mail:
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Cao B, Tan TT, Poon E, Wang JT, Kumar S, Liam CHK, Ahmed K, Moral P, Qiu H, Barez MY, Buntaran L, Tampubolon OE, Thamlikitkul V. Consensus statement on the management of methicillin-resistant Staphylococcus aureus nosocomial pneumonia in Asia. CLINICAL RESPIRATORY JOURNAL 2014; 9:129-42. [PMID: 24725393 DOI: 10.1111/crj.12134] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 03/06/2014] [Accepted: 04/04/2014] [Indexed: 12/26/2022]
Abstract
Nosocomial pneumonia (NP; encompassing hospital-acquired, health care-associated and ventilator-associated pneumonia) is one of the most common nosocomial infections and is associated with a mortality rate of 18.7%-40.8% in Asian countries. The burden of methicillin-resistant Staphylococcus aureus (MRSA) infections in Asia is high, and approximately 13% of NP cases in Asia are caused by this pathogen. Evidence regarding optimal management of MRSA NP continues to evolve and is complicated by the fact that a significant proportion of cases are likely to be caused by isolates with reduced susceptibility to the main therapeutic agent, vancomycin. The Asian Consensus Taskforce on MRSA Nosocomial Pneumonia has developed this statement to provide consensus points on diagnosis, antimicrobial treatment and prevention strategies for MRSA NP in the Asian context, based on our review of Asian data, previous international guidelines and recent scientific evidence.
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Affiliation(s)
- Bin Cao
- Department of Infectious Diseases and Clinical Microbiology, Beijing Chaoyang Hospital, Capital Medical University Beijing, Beijing, China
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Liu C, Chen ZJ, Sun Z, Feng X, Zou M, Cao W, Wang S, Zeng J, Wang Y, Sun M. Molecular characteristics and virulence factors in methicillin-susceptible, resistant, and heterogeneous vancomycin-intermediate Staphylococcus aureus from central-southern China. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2014; 48:490-6. [PMID: 24767415 DOI: 10.1016/j.jmii.2014.03.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 03/06/2014] [Accepted: 03/10/2014] [Indexed: 11/18/2022]
Abstract
BACKGROUND Staphylococcus aureus is a leading cause of nosocomial infections. The purpose of this study was to evaluate the prevalence of methicillin-resistant S. aureus (MRSA) and heterogeneous vancomycin-intermediate S. aureus (hVISA), and compare the antimicrobial susceptibility, molecular characteristic, and virulence factors in methicillin-susceptible S. aureus (MSSA), MRSA, and hVISA from central-southern China. METHODS A total of 184 S. aureus were isolated from sterile body fluids. All isolates were subjected to population analysis profiling for the identification of hVISA phenotype and polymerase chain reaction analysis for genotyping and 31 virulence genes. RESULTS The prevalence of MRSA isolates was 41.8% in central-southern China. Of 77 MRSA isolates, 17 (22.1%) were identified as hVISA. The most common MRSA and MSSA clones were ST239-MRSA-SCCmecIII-t030-agr-I (55.8%) and ST188-MSSA-t189-agr-I (20.6%), respectively. The frequency of carriage of pvl, hemolysins, tst, and staphylococcal enterotoxin genes among MSSA isolates was significantly higher than that for MRSA isolates (p < 0.05); 98 MSSA isolates (53.3%) carried ≥ 10 tested virulence genes simultaneously, which was significantly higher than that of MRSA isolates (33.8%; p = 0.004). The 17 hVISA isolates carried a significantly small number of virulence genes; only two hVISA isolates carried ≥ 10 tested virulence genes simultaneously, and two hVISA isolates harbored only four virulence genes. Compared with other clonal complexes (CCs), CC1 and CC398 isolates harbored a higher frequency of exfoliatin genes, CC1 and CC59 harbored a higher frequency of pvl gene, and only CC1 isolates harbored lukED. CONCLUSION The prevalence of hVISA was considerably high in central-southern China. Simultaneous carriage of multiple virulence genes was common in S. aureus isolates; the virulence genes were more diverse and frequent among MSSA isolates than among MRSA isolates. Furthermore, the distribution of some virulence genes was correlated with the different S. aureus CCs.
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Affiliation(s)
- Cailin Liu
- Department of Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhong-ju Chen
- Department of Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ziyong Sun
- Department of Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Xianju Feng
- Department of Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Mingxiang Zou
- Department of Laboratory, Xiangya Hospital of Central South University, Changsha, China
| | - Wei Cao
- Department of Laboratory, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Shanmei Wang
- Department of Laboratory, Henan Province People's Hospital, Zhengzhou, China
| | - Ji Zeng
- Department of Laboratory, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yue Wang
- Department of Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Mingyue Sun
- Department of Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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High vancomycin minimum inhibitory concentrations with heteroresistant vancomycin-intermediate Staphylococcus aureus in meticillin-resistant S. aureus bacteraemia patients. Int J Antimicrob Agents 2013; 42:390-4. [DOI: 10.1016/j.ijantimicag.2013.07.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 07/11/2013] [Accepted: 07/23/2013] [Indexed: 11/13/2022]
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Seah J, Lye DC, Ng TM, Krishnan P, Choudhury S, Teng CB. Vancomycin monotherapy vs. combination therapy for the treatment of persistent methicillin-resistant Staphylococcus aureus bacteremia. Virulence 2013; 4:734-9. [PMID: 24165210 PMCID: PMC3925706 DOI: 10.4161/viru.26909] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Jonathan Seah
- Department of Pharmacy; Changi General Hospital; Singapore
| | - David C Lye
- Department of Infectious Diseases; Tan Tock Seng Hospital; Singapore; Communicable Disease Centre; Singapore; Department of Medicine; Yong Loo Lin School of Medicine; National University of Singapore; Singapore
| | - Tat-Ming Ng
- Department of Pharmacy; Tan Tock Seng Hospital; Singapore
| | - Prabha Krishnan
- Department of Microbiology; Tan Tock Seng Hospital; Singapore
| | | | - Christine B Teng
- Department of Pharmacy; Tan Tock Seng Hospital; Singapore; Department of Pharmacy; Faculty of Science; National University of Singapore; Singapore
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Clinical Outcomes in Patients with Heterogeneous Vancomycin-Intermediate Staphylococcus aureus Bloodstream Infection. Antimicrob Agents Chemother 2013; 57:4252-4259. [PMID: 23796929 DOI: 10.1128/aac.00380-13] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 06/14/2013] [Indexed: 01/30/2023] Open
Abstract
The prevalence of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) infections varies in the literature, a problem complicated by the lack of routine screening procedures; however, limited data suggest that hVISA has been associated with persistent bloodstream infections (BSI) and vancomycin failure, yet these studies have been confounded by design issues. We conducted this study to compare the characteristics of patients with BSI caused by hVISA with those with vancomycin-susceptible Staphylococcus aureus (VSSA) treated with vancomycin. This retrospective, multicenter matched (1:1) cohort study compared the clinical characteristics and outcomes of hVISA and VSSA. Patients with hVISA methicillin-resistant Staphylococcus aureus (MRSA) BSI from 2004 to 2012 were matched to VSSA-MRSA BSI patients. The primary outcome was failure of vancomycin treatment, defined as a composite of persistent bacteremia (≥7 days), persistent signs and symptoms, change of MRSA antibiotic, recurrent BSI, or MRSA-related mortality. We identified 122 matched cases. The overall vancomycin failure rate was 57% (82% hVISA versus 33% VSSA; P < 0.001). The individual components of failure in hVISA versus VSSA were persistent bacteremia, 59% versus 21% (P < 0.001); change in MRSA therapy, 54% versus 25% (P = 0.001); MRSA-related mortality, 21% versus 10% (P = 0.081); and recurrence of BSI, 26% versus 2% (P < 0.001). Using logistic regression analysis and adjusting for covariates, hVISA (adjusted odds ratio [aOR], 11.1; 95% confidence interval [CI], 4.3 to 28.7) and intensive care unit (ICU) admission (aOR, 4.5; 95% CI, 1.8 to 11.6) were still independently associated with vancomycin failure. Relative to VSSA BSI, patients with hVISA were more likely to experience failure of vancomycin treatment, including persistent bacteremia and recurrence. Our results indicate that hVISA was responsible for considerable morbidity.
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Kang CI, Song JH. Antimicrobial resistance in Asia: current epidemiology and clinical implications. Infect Chemother 2013; 45:22-31. [PMID: 24265947 PMCID: PMC3780932 DOI: 10.3947/ic.2013.45.1.22] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Indexed: 11/24/2022] Open
Abstract
Antimicrobial resistance has become one of the most serious public health concerns worldwide. Although circumstances may vary by region or country, it is clear that some Asian countries are epicenters of resistance, having seen rapid increases in the prevalence of antimicrobial resistance of major bacterial pathogens. In these locations, however, the public health infrastructure to combat this problem is very poor. The prevalence rates of methicillin-resistant Staphylococcus aureus (MRSA), macrolide-resistant Streptococcus pneumoniae, and multidrug-resistant enteric pathogens are very high due to the recent emergence of extremely drug-resistant gram-negative bacilli in Asia. Because antimicrobial options for these pathogens are extremely limited, infections caused by antimicrobial-resistant bacteria are often associated with inappropriate antimicrobial therapy and poor clinical outcomes. Physicians should be aware of the current epidemiological status of resistance and understand the appropriate use of antimicrobial agents in clinical practice. This review focuses on describing the epidemiology and clinical implications of antimicrobial-resistant bacterial infections in Asian countries.
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Affiliation(s)
- Cheol-In Kang
- Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Molton JS, Tambyah PA, Ang BSP, Ling ML, Fisher DA. The global spread of healthcare-associated multidrug-resistant bacteria: a perspective from Asia. Clin Infect Dis 2013; 56:1310-8. [PMID: 23334810 DOI: 10.1093/cid/cit020] [Citation(s) in RCA: 221] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Since antibiotics were first used, each new introduced class has been followed by a global wave of emergent resistance, largely originating in Europe and North America where they were first used. Methicillin-resistant Staphylococcus aureus spread from the United Kingdom and North America across Europe and then Asia over more than a decade. Vancomycin-resistant enterococci and Klebsiella pneumoniae carbapenemase-producing K. pneumoniae followed a similar path some 20 years later. Recently however, metallo-β-lactamases have originated in Asia. New Delhi metallo-β-lactamase-1 was found in almost every continent within a year of its emergence in India. Metallo-β-lactamase enzymes are encoded on highly transmissible plasmids that spread rapidly between bacteria, rather than relying on clonal proliferation. Global air travel may have helped facilitate rapid dissemination. As the antibiotic pipeline offers little in the short term, our most important tools against the spread of antibiotic resistant organisms are intensified infection control, surveillance, and antimicrobial stewardship.
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Affiliation(s)
- James S Molton
- Division of Infectious Diseases, National University Health System, Level 10, Department of Medicine, 1E Kent Ridge Road, Singapore 119228
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Molecular epidemiology and clinical characteristics of hetero-resistant vancomycin intermediate Staphylococcus aureus bacteremia in a Taiwan Medical Center. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2012; 45:435-41. [DOI: 10.1016/j.jmii.2012.05.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 07/14/2011] [Accepted: 08/11/2011] [Indexed: 11/20/2022]
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Takata T, Miyazaki M, Futo M, Hara S, Shiotsuka S, Kamimura H, Yoshimura H, Matsunaga A, Nishida T, Ishikura H, Ishikawa T, Tamura K, Tsuji BT. Presence of both heterogeneous vancomycin-intermediate resistance and β-lactam antibiotic-induced vancomycin resistance phenotypes is associated with the outcome in methicillin-resistant Staphylococcus aureus bloodstream infection. ACTA ACUST UNITED AC 2012; 45:203-12. [PMID: 23113753 DOI: 10.3109/00365548.2012.723221] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Although the individual expression of heterogeneous vancomycin-intermediate resistance (hVISA) and β-lactam antibiotic-induced vancomycin resistance (BIVR) phenotypes has been associated with treatment failure and recurrence in methicillin-resistant Staphylococcus aureus (MRSA) infections, the effect of the co-expression of these phenotypic profiles on clinical outcome has not been fully elucidated. The aim of this study was to determine the impact of the combination of hVISA and BIVR phenotypes on the clinical outcome in MRSA bacteremia. METHODS One hundred and sixty-two MRSA blood isolates from a 21-y period, 1987-2007, were randomly selected. Screening for hVISA was done by the macromethod Etest and confirmed by population analysis profiles. BIVR was identified using Mu3 agar containing 4 μg/ml of vancomycin. RESULTS Thirty (18.5%) and 39 (24.1%) of the 162 MRSA blood isolates were positive for the hVISA and BIVR phenotypes, respectively. Eighteen (11.1%) isolates possessed both hVISA and BIVR phenotypes (hVISA(+)/BIVR(+)). In a subset of patients who received initial treatment with glycopeptides, only the patients whose isolates were hVISA(+)/BIVR(+) displayed a significantly higher mortality rate in comparison to those with non-hVISA(+)/BIVR(+) (80.0% vs 31.3%, p = 0.004). The presence of both hVISA and BIVR phenotypes was a predictor of mortality using a logistic regression analysis (p = 0.025). CONCLUSIONS The combined phenotype of hVISA and BIVR was associated with a higher probability of mortality in patients with MRSA bacteremia. Further prospective studies are warranted to delineate the clinical significance of the combined phenotype of hVISA and BIVR.
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Affiliation(s)
- Tohru Takata
- Division of Oncology, Department of Medicine, Fukuoka University School of Medicine, Fukuoka University School ofMedicine, Fukuoka, Japan.
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Leonard SN. Synergy between vancomycin and nafcillin against Staphylococcus aureus in an in vitro pharmacokinetic/pharmacodynamic model. PLoS One 2012; 7:e42103. [PMID: 22848719 PMCID: PMC3404091 DOI: 10.1371/journal.pone.0042103] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 07/02/2012] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Continued pressure from glycopeptide use has led to non-susceptible strains of Staphylococcus aureus including heterogeneously vancomycin-intermediate S. aureus (hVISA). Infections with hVISA are associated with poor patient outcomes, thus incentivizing novel treatments. Evidence suggests that vancomycin and anti-staphylococcal penicillin susceptibility are inversely related which indicates that the use of this combination may be particularly useful against methicillin-resistant S. aureus with reduced susceptibility to vancomycin, such as hVISA. The aim of this study was to evaluate the potential for synergy between vancomycin and nafcillin against hVISA. METHODS Twenty-five hVISA strains were evaluated for vancomycin and nafcillin minimum inhibitory concentration (MIC) by broth microdilution in duplicate. Potential for synergy was assessed by time-kill at 1/2x MIC in triplicate. Five strains were chosen, representing the range nafcillin MIC's available in the cohort -4, 16, 64, 128, and 256 µg/mL, and were run in an in vitro pharmacokinetic/pharmacodynamic (PK/PD) model in duplicate over 72 hours to evaluate the potential of the combination with simulated human pharmacokinetics. In addition, 4 fully glycopeptide susceptible strains of S. aureus including 2 methicillin-susceptible (MSSA) and 2 methicillin-resistant (MRSA) were run in the PK/PD model for comparison. RESULTS In the time-kill, 92% of strains (23 of 25) displayed synergy with the combination of vancomycin and nafcillin. In the PK/PD model, all five strains of hVISA showed an improvement in overall activity (P≤0.004) and organism burden at 72 hours (P≤0.001) with the combination compared to either drug alone. The combination was also successful against both MRSA and MSSA in overall activity (P≤0.009) and organism burden at 72 hours (P≤0.016), though the magnitude of the effect was diminished against MSSA. CONCLUSIONS The combination of vancomycin and nafcillin significantly improved antibacterial activity against hVISA, MRSA, and MSSA compared to either drug alone.
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Affiliation(s)
- Steven N Leonard
- School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts, United States of America.
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Park KH, Kim ES, Kim HS, Park SJ, Bang KM, Park HJ, Park SY, Moon SM, Chong YP, Kim SH, Lee SO, Choi SH, Jeong JY, Kim MN, Woo JH, Kim YS. Comparison of the clinical features, bacterial genotypes and outcomes of patients with bacteraemia due to heteroresistant vancomycin-intermediate Staphylococcus aureus and vancomycin-susceptible S. aureus. J Antimicrob Chemother 2012; 67:1843-9. [DOI: 10.1093/jac/dks131] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Sivakumar B, Vijaysegaran P, Chaudhuri A, Crawford S, Ottley M. Daptomycin resistance in prosthetic joint infections. Orthopedics 2012; 35:e603-6. [PMID: 22495870 DOI: 10.3928/01477447-20120327-42] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Antimicrobial resistance has been problematic since the advent of antibiotics. Patients with prosthetic joint infections often require prolonged courses of antibiotic therapy, with resistance commonly being the consequence. The rapid evolution of resistance poses a serious challenge in the treatment of infections and creates a need for new agents with novel mechanisms of bactericidal activity. Daptomycin, a cyclic lipopeptide naturally produced by Streptomyces roseosporus, is a newer agent approved for use in complicated skin, soft tissue, and prosthetic joint infections. To our knowledge, this article describes the first case of daptomycin-resistant heterogenous vancomycin intermediate-resistant Staphylococcus aureus (hVISA) in an 82-year-old man undergoing elective total knee arthroplasty in Queensland, Australia, with a subsequent deep prosthetic joint infection.A literature review is presented, and the increasing number of multi-resistant organisms and their implications for orthopedics are discussed. Worldwide reports of hVISA are reviewed. To our knowledge, this is the first article to describe daptomycin resistance in prosthetic joint infections. The role of newer antimicrobial agents, such as daptomycin, and strategies to minimize antibiotic resistance are examined.
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Affiliation(s)
- Brahman Sivakumar
- Department of Orthopedic Surgery, The Prince Charles Hospital, Chermside, Australia
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van Hal SJ, Jensen SO, Vaska VL, Espedido BA, Paterson DL, Gosbell IB. Predictors of mortality in Staphylococcus aureus Bacteremia. Clin Microbiol Rev 2012; 25:362-86. [PMID: 22491776 PMCID: PMC3346297 DOI: 10.1128/cmr.05022-11] [Citation(s) in RCA: 639] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus bacteremia (SAB) is an important infection with an incidence rate ranging from 20 to 50 cases/100,000 population per year. Between 10% and 30% of these patients will die from SAB. Comparatively, this accounts for a greater number of deaths than for AIDS, tuberculosis, and viral hepatitis combined. Multiple factors influence outcomes for SAB patients. The most consistent predictor of mortality is age, with older patients being twice as likely to die. Except for the presence of comorbidities, the impacts of other host factors, including gender, ethnicity, socioeconomic status, and immune status, are unclear. Pathogen-host interactions, especially the presence of shock and the source of SAB, are strong predictors of outcomes. Although antibiotic resistance may be associated with increased mortality, questions remain as to whether this reflects pathogen-specific factors or poorer responses to antibiotic therapy, namely, vancomycin. Optimal management relies on starting appropriate antibiotics in a timely fashion, resulting in improved outcomes for certain patient subgroups. The roles of surgery and infectious disease consultations require further study. Although the rate of mortality from SAB is declining, it remains high. Future international collaborative studies are required to tease out the relative contributions of various factors to mortality, which would enable the optimization of SAB management and patient outcomes.
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Affiliation(s)
- Sebastian J van Hal
- Department of Microbiology and Infectious Diseases, Sydney South West Pathology Service—Liverpool, South Western Sydney Local Health Network, Sydney, New South Wales, Australia.
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Abstract
OBJECTIVE To determine whether exposure to antimicrobial agents in the previous 90 days resulted in decreased bacterial susceptibility and increased hospital mortality in patients with severe sepsis or septic shock attributed to Gram-negative bacteremia. DESIGN A retrospective cohort study of hospitalized patients (January 2002 to December 2007). SETTING Barnes-Jewish Hospital, a 1200-bed urban teaching hospital. PATIENTS Seven hundred fifty-four consecutive patients with Gram-negative bacteremia complicated by severe sepsis or septic shock. INTERVENTIONS Data abstraction from computerized medical records. MEASUREMENTS AND MAIN RESULTS Escherichia coli (30.8%), Klebsiella pneumoniae (23.2%), and Pseudomonas aeruginosa (17.6%) were the most common isolates from blood cultures. Three hundred ten patients (41.1%) had recent antibiotic exposure. Cefepime was the most common agent with previous exposure (50.0%) followed by ciprofloxacin (32.6%) and imipenem or meropenem (28.7%). Patients with prior antibiotic exposure had significantly higher rates of resistance to cefepime (29.0% vs. 7.0%), piperacillin/tazobactam (31.9% vs. 11.5%), carbapenems (20.0% vs. 2.5%), ciprofloxacin (39.7% vs. 17.6%), and gentamicin (26.1% vs. 7.9%) (p < .001 for all comparisons). Patients with recent antibiotic exposure had greater inappropriate initial antimicrobial therapy (45.4% vs. 21.2%; p < .001) and hospital mortality (51.3% vs. 34.0%; p < .001) compared with patients without recent antibiotic exposure. Multivariate logistic regression analysis demonstrated that recent antibiotic exposure was independently associated with hospital mortality (adjusted odds ratio, 1.70; 95% confidence interval, 1.41-2.06; p = .005). Other variables independently associated with hospital mortality included use of vasopressors, infection resulting from P. aeruginosa, inappropriate initial antimicrobial therapy, increasing Acute Physiology and Chronic Health Evaluation II scores, and the number of acquired organ failures. CONCLUSIONS Recent antibiotic exposure is associated with increased hospital mortality in Gram-negative bacteremia complicated by severe sepsis or septic shock. Clinicians caring for patients with severe sepsis or septic shock should consider recent antibiotic exposure when formulating empiric antimicrobial regimens for suspected Gram-negative bacterial infection.
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Abstract
AIMS To highlight the challenges involved in diagnosing and managing complicated heterogeneous vancomycin intermediate Staphylococcus aureus (hVISA) infections and to improve clinical recognition of such infections. METHODS A retrospective review of patients with proven hVISA infections was undertaken in two major referral centres of North Queensland from 2006 to 2010. All isolates had population analysis profiling (PAP) done along with hVISA screening performed by the macro-Etest (MET). RESULTS Five patients were identified, two of whom died of hVISA-related sepsis. Their population analysis profiling-area-under-the-curve ratio (PAP-AUC) ranged between 0.96 and 1.43. CONCLUSIONS The identification of hVISA isolates in the diagnostic laboratory presents specific challenges. Clinical failure with vancomycin or MICs to vancomycin of ≥2 mg/L should alert the laboratory to proceed with the more specific methods of MET and PAP to identify hVISA or VISA isolates. Alternatives to vancomycin are limited and not always efficacious or tolerated.
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Walraven CJ, North MS, Marr-Lyon L, Deming P, Sakoulas G, Mercier RC. Site of infection rather than vancomycin MIC predicts vancomycin treatment failure in methicillin-resistant Staphylococcus aureus bacteraemia. J Antimicrob Chemother 2011; 66:2386-92. [PMID: 21775337 DOI: 10.1093/jac/dkr301] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Therapeutic use of vancomycin is characterized by decreased susceptibilities and increasing reports of clinical failures. Few studies have examined the clinical outcomes of patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia treated with vancomycin. The primary objective was to compare clinical outcomes of patients with MRSA bacteraemia treated according to standard of care practices. METHODS Patients were included if: (i) admitted to University of New Mexico Hospital between 2002 and 2009; (ii) ≥18 years of age; (iii) had one blood culture positive for MRSA; and (iv) received vancomycin. Clinical outcomes were defined as cure, failure (relapse of infection 30 days after completion of therapy, death or change in therapy) or unevaluable. Patient demographics, source of bacteraemia, treatment regimen, and microbiological characteristics were determined. RESULTS Two hundred patients with MRSA bacteraemia were included. Sixty-one patients were unevaluable, leaving 139 patients for the final analysis. Seventy-two (51.8%) patients were cured and 67 (48.2%) experienced vancomycin failure. Vancomycin MIC(90) was 2 mg/L for both groups by Etest. Patients with endocarditis (P = 0.02) or pneumonia (P = 0.02) were more likely to fail therapy. Panton-Valentine leucocidin, loss of agr functionality and strain type were not predictors of outcomes in this study. CONCLUSIONS High failure rates were observed in patients with MRSA bacteraemia treated with vancomycin, despite high vancomycin troughs and low rates of nephrotoxicity. Predictors of vancomycin failure included endocarditis and pneumonia. In these situations, vancomycin provides suboptimal therapy.
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Affiliation(s)
- Carla J Walraven
- College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87106, USA.
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Systematic review and meta-analysis of the significance of heterogeneous vancomycin-intermediate Staphylococcus aureus isolates. Antimicrob Agents Chemother 2010; 55:405-10. [PMID: 21078939 DOI: 10.1128/aac.01133-10] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The prevalence of heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) is 1.3% in published studies. Clinical associations include high-inoculum infections and glycopeptide failure, with hVISA infections associated with a 2.37-times-greater failure rate (95% confidence interval [CI], 1.53 to 3.67) compared to vancomycin-sensitive Staphylococcus aureus (VSSA) infections. Despite this, 30-day mortality rates were similar to those for VSSA infections (odds ratio [OR], 1.18; 95% CI, 0.81 to 1.74). The optimal therapy for hVISA requires further study.
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Abstract
An increasing proportion of Staphylococcus aureus infections are caused by methicillin-resistant S aureus. Treatment of infections caused by this organism is challenging, especially because therapy with vancomycin, the traditional antibiotic of choice for methicillin-resistant S aureus infections, is associated with an increasing frequency of treatment failure, and vancomycin insensitive and vancomycin-resistant strains have emerged. In addition, Enterococcus sp. isolated from human infections are increasingly resistant to multiple antimicrobial agents. Newer drugs available for treatment of resistant Gram-positive bacterial infections in the United States include linezolid, daptomycin, tigecycline and telavancin. The precise role for these newer agents is still evolving. Organisms resistant to each of these antimicrobials have emerged. New drugs in development include cephalosporins and carbapenems with MRSA activity.
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Putnam SD, Sader HS, Moet GJ, Mendes RE, Jones RN. Worldwide summary of telavancin spectrum and potency against Gram-positive pathogens: 2007 to 2008 surveillance results. Diagn Microbiol Infect Dis 2010; 67:359-68. [DOI: 10.1016/j.diagmicrobio.2010.03.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Accepted: 03/18/2010] [Indexed: 11/28/2022]
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Rong SL, Leonard SN. Heterogeneous Vancomycin Resistance in Staphylococcus Aureus: A Review of Epidemiology, Diagnosis, and Clinical Significance. Ann Pharmacother 2010; 44:844-50. [DOI: 10.1345/aph.1m526] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE: To provide an overview of heterogeneously glycopeptide intermediate Staphylococcus aureus, its epidemiology, methods of diagnosis, and clinical relevance. DATA SOURCES: Literature was retrieved in December 2009 through Academic Search Premier, Alt-Health Watch, MEDLINE, OVID, and PubMed, using the search terms heterogeneous glycopeptide-intermediate Staphylococcus aureus, hGISA, hVISA, vancomycin-intermediate Staphylococcus aureus, GISA, and VISA (from 2003 to December 2009). Additional references were obtained through review of publication citations. STUDY SELECTION AND DATA EXTRACTION: All articles retrieved through the literature search and reference review were evaluated for inclusion in this review. DATA SYNTHESIS: Heterogeneously glycopeptide-intermediate S. aureus (hGISA) has been shown to significantly complicate treatment for patients with bacteremia and often escapes detection in clinical laboratories. Population analysis profile area under the curve ratio (PAP-AUC) is considered to be the gold standard of hGISA detection; however, it is labor-intensive, expensive, and not feasible in a clinical setting. The Etest macromethod is a reasonable alternative to PAP, yielding high sensitivity and specificity, and has potential for routine use in clinical laboratories. Due to these difficulties in detection, an exact prevalence is difficult to obtain though, based on available data, it appears that approximately 5-15% of isolates display this phenotype. hGISA is associated with prolonged bacteremia, high bacterial load infections, prolonged antibiotic therapy, prolonged hospitalization, treatment failure, and potential for increased mortality. CONCLUSIONS: Overall, hGISA is associated with a poor clinical course in patients with bacteremia. Information is still lacking regarding the actual prevalence of hGISA as well as the extent of its clinical impact. A uniform method of diagnosis must be established in order to better account for all cases of hGISA. More studies must be conducted to assess clinical outcomes of hGISA.
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Affiliation(s)
- Star L Rong
- Star L Rong, PharmD student, School of Pharmacy, Northeastern University, Boston, MA
| | - Steven N Leonard
- Steven N Leonard PharmD, Assistant Professor, School of Pharmacy, Northeastern University; Clinical Pharmacist, Department of Pharmacy, Brigham and Women's Hospital, Boston, MA
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