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Wu W, Mu Y. Microfluidic technologies for advanced antimicrobial susceptibility testing. BIOMICROFLUIDICS 2024; 18:031504. [PMID: 38855477 PMCID: PMC11162290 DOI: 10.1063/5.0190112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 05/23/2024] [Indexed: 06/11/2024]
Abstract
Antimicrobial resistance is getting serious and becoming a threat to public health worldwide. The improper and excessive use of antibiotics is responsible for this situation. The standard methods used in clinical laboratories, to diagnose bacterial infections, identify pathogens, and determine susceptibility profiles, are time-consuming and labor-intensive, leaving the empirical antimicrobial therapy as the only option for the first treatment. To prevent the situation from getting worse, evidence-based therapy should be given. The choosing of effective drugs requires powerful diagnostic tools to provide comprehensive information on infections. Recent progress in microfluidics is pushing infection diagnosis and antimicrobial susceptibility testing (AST) to be faster and easier. This review summarizes the recent development in microfluidic assays for rapid identification and AST in bacterial infections. Finally, we discuss the perspective of microfluidic-AST to develop the next-generation infection diagnosis technologies.
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Affiliation(s)
- Wenshuai Wu
- Department of Nutrition and Food Hygiene, School of Public Health, Southeast University, Nanjing 210009, China
| | - Ying Mu
- Author to whom correspondence should be addressed:
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Wu W, Suo Y, Zhao Q, Cai G, Liu Y, Jin W, Mu Y, Zhang B. Inoculum size-insensitive susceptibility determination of urine sample based on in-situ measurement of inducible enzyme activity after 20 min of antibiotic exposure. Anal Chim Acta 2023; 1282:341858. [PMID: 37923403 DOI: 10.1016/j.aca.2023.341858] [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: 07/29/2023] [Revised: 09/28/2023] [Accepted: 09/28/2023] [Indexed: 11/07/2023]
Abstract
BACKGROUND The empirical antibiotic therapies for bacterial infections cause the emergence and propagation of multi-drug resistant bacteria, which not only impair the effectiveness of existing antibiotics but also raise healthcare costs. To reduce the empirical treatments, rapid antimicrobial susceptibility testing (AST) of causative microorganisms in clinical samples should be conducted for prescribing evidence-based antibiotics. However, most of culture-based ASTs suffer from inoculum effect and lack differentiation of target pathogen and commensals, hampering their adoption for evidence-based antibiotic prescription. Therefore, rapid ASTs which can specifically determine pathogens' susceptibilities, regardless of the bacterial load in clinical samples, are in urgent need. RESULTS We present a pathogen-specific and inoculum size-insensitive AST to achieve the reliable susceptibility determination on Escherichia coli (E. coli) in urine samples. The developed AST is featured with an 1 h sample-to-result workflow in a filter, termed on-filter AST. The AST results can be obtained by using an inducible enzymatic assay to in-situ measure the cell response of E. coli collected from urine after 20 min of antibiotic exposure. The calculated detection limit of our AST (1.95 × 104 CFU/mL) is much lower than the diagnosis threshold of urinary tract infections. The specific expression of the inducible enzyme enables on-filter AST to correctly profile the susceptibilities of target pathogen to multi-type antibiotics without the interference from commensals. We performed the on-filter AST on 1 mL urine samples with bacterial loads varying from 105 CFU/mL to 107 CFU/mL and compared the results to that of standard method, demonstrating its insensitivity to inoculum size. SIGNIFICANCE The developed AST is demonstrated to be of high sensitivity, specificity, and insensitive to inoculum size. With further developments for additional bacteria and clinical validation, on-filter AST is promising as a rapid and reliable surrogate of culture-based AST to promote the evidence-based prescription at the first visit and minimize the emergency of new multi-drug resistant microorganisms.
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Affiliation(s)
- Wenshuai Wu
- Research Center for Analytical Instrumentation, Institute of Cyber-Systems and Control, State Key Laboratory of Industrial Control Technology, Zhejiang University, Hangzhou, 310027, China
| | - Yuanjie Suo
- Research Center for Analytical Instrumentation, Institute of Cyber-Systems and Control, State Key Laboratory of Industrial Control Technology, Zhejiang University, Hangzhou, 310027, China
| | - Qianbin Zhao
- Center of Health Science and Engineering, Hebei Key Laboratory of Biomaterials and Smart Theranostics, Hebei University of Technology, Tianjin, 300131, China
| | - Gaozhe Cai
- School of Microelectronics, Shanghai University, Shanghai, 200444, China
| | - Yang Liu
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing, 102401, China
| | - Wei Jin
- Research Center for Analytical Instrumentation, Institute of Cyber-Systems and Control, State Key Laboratory of Industrial Control Technology, Zhejiang University, Hangzhou, 310027, China; Huzhou Institute of Zhejiang University, Huzhou, 313002, China
| | - Ying Mu
- Research Center for Analytical Instrumentation, Institute of Cyber-Systems and Control, State Key Laboratory of Industrial Control Technology, Zhejiang University, Hangzhou, 310027, China.
| | - Boran Zhang
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, China.
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Potvin M, Larranaga Lapique E, Hites M, Martiny D. Implementing Alfred60 AST in a clinical lab: Clinical impact on the management of septic patients and financial analysis. ANNALES PHARMACEUTIQUES FRANÇAISES 2023; 81:466-474. [PMID: 36402206 DOI: 10.1016/j.pharma.2022.11.009] [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: 05/17/2022] [Revised: 07/22/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Sepsis is an important cause of morbidity and mortality. An accelerated microbiology diagnosis is crucial in order to reduce the time to initiate targeted antibiotic therapy. The Alfred60AST system is able to provide phenotypic Antimicrobial Susceptibility Testing (AST) results within hours. This study has two objectives: assess the clinical impact of this technology and determine its cost-effectiveness. METHODS During a ten-week period, all new enterobacterial or enterococcal bloodstream infection was analyzed with the Alfred60AST system, in parallel with routine methods. Its impact on the clinician's therapeutic strategy was studied. In order to assess the financial and practical aspects of the method, an analysis of the extracosts and a survey of the technical staff were conducted. RESULTS Fifty-three cases of bacteriemia were included. For the Enterobacteriaceae bacteriemias, a clinical impact was shown in 18.9% of the cases (e.g, treatment modification). The financial analysis highlighted an increase in costs (+38% for Enterobacteriaceae, +50% for Enterococci), compared to the theoretical costs reported by the firm, due to the workflow and the volumes of samples used. Finally, results of the technical staff survey were favorable in terms of ease of use of the system. CONCLUSION In addition to its ease of use, the Alfred60AST system is able to provide an AST in a record time. This study shows a real interest of the technique in the therapeutic management of patients with enterobacterial sepsis. However, its routine implementation requires an increase of the analyzed volumes as well as a 24/7 organization of the laboratory in order to be profitable.
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Affiliation(s)
- M Potvin
- Microbiology Department, LHUB-ULB, rue haute, 322, 1000 Brussels, Belgium.
| | - E Larranaga Lapique
- Department of Infectious Disease, Erasme Hospital, route de Lennik, 808, 1070 Brussels, Belgium
| | - M Hites
- Department of Infectious Disease, Erasme Hospital, route de Lennik, 808, 1070 Brussels, Belgium
| | - D Martiny
- Microbiology Department, LHUB-ULB, rue haute, 322, 1000 Brussels, Belgium
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Li C, McCrone S, Warrick JW, Andes DR, Hite Z, Volk CF, Rose WE, Beebe DJ. Under-oil open microfluidic systems for rapid phenotypic antimicrobial susceptibility testing. LAB ON A CHIP 2023; 23:2005-2015. [PMID: 36883560 PMCID: PMC10581760 DOI: 10.1039/d3lc00066d] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Antimicrobial susceptibility testing (AST) remains the cornerstone of effective antimicrobial selection and optimization in patients. Despite recent advances in rapid pathogen identification and resistance marker detection with molecular diagnostics (e.g., qPCR, MALDI-TOF MS), phenotypic (i.e., microbial culture-based) AST methods - the gold standard in hospitals/clinics - remain relatively unchanged over the last few decades. Microfluidics-based phenotypic AST has been growing fast in recent years, aiming for rapid (i.e., turnaround time <8 h), high-throughput, and automated species identification, resistance detection, and antibiotics screening. In this pilot study, we describe the application of a multi-liquid-phase open microfluidic system, named under-oil open microfluidic systems (UOMS), to achieve a rapid phenotypic AST. UOMS provides an open microfluidics-based solution for rapid phenotypic AST (UOMS-AST) by implementing and recording a pathogen's antimicrobial activity in micro-volume testing units under an oil overlay. UOMS-AST allows free physical access (e.g., by standard pipetting) to the system and label-free, single-cell resolution optical access. UOMS-AST can accurately and rapidly determine antimicrobial activities [including susceptibility/resistance breakpoint and minimum inhibitory concentration (MIC)] from nominal sample/bacterial cells in a system aligned with clinical laboratory standards where open systems and optical microscopy are predominantly adopted. Further, we combine UOMS-AST with a cloud lab data analytic technique for real-time image analysis and report generation to provide a rapid (<4 h) sample-to-report turnaround time, shedding light on its utility as a versatile (e.g., low-resource setting and manual laboratory operation, or high-throughput automated system) phenotypic AST platform for hospital/clinic use.
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Affiliation(s)
- Chao Li
- Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Sue McCrone
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Jay W. Warrick
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - David R. Andes
- Department of Medicine, Division of Infectious Diseases, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Zachary Hite
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Cecilia F. Volk
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Warren E. Rose
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Medicine, Division of Infectious Diseases, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - David J. Beebe
- Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI 53705, USA
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β-Lactam Therapeutic Drug Monitoring in Critically Ill Patients: Weighing the Challenges and Opportunities to Assess Clinical Value. Crit Care Explor 2022; 4:e0726. [PMID: 35815181 PMCID: PMC9259115 DOI: 10.1097/cce.0000000000000726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE: DATA SOURCES: STUDY SELECTION: DATA EXTRACTION: DATA SYNTHESIS: CONCLUSIONS:
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Antimicrobial Susceptibility Testing: A Comprehensive Review of Currently Used Methods. Antibiotics (Basel) 2022; 11:antibiotics11040427. [PMID: 35453179 PMCID: PMC9024665 DOI: 10.3390/antibiotics11040427] [Citation(s) in RCA: 78] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/18/2022] [Accepted: 03/18/2022] [Indexed: 02/04/2023] Open
Abstract
Antimicrobial resistance (AMR) has emerged as a major threat to public health globally. Accurate and rapid detection of resistance to antimicrobial drugs, and subsequent appropriate antimicrobial treatment, combined with antimicrobial stewardship, are essential for controlling the emergence and spread of AMR. This article reviews common antimicrobial susceptibility testing (AST) methods and relevant issues concerning the advantages and disadvantages of each method. Although accurate, classic technologies used in clinical microbiology to profile antimicrobial susceptibility are time-consuming and relatively expensive. As a result, physicians often prescribe empirical antimicrobial therapies and broad-spectrum antibiotics. Although recently developed AST systems have shown advantages over traditional methods in terms of testing speed and the potential for providing a deeper insight into resistance mechanisms, extensive validation is required to translate these methodologies to clinical practice. With a continuous increase in antimicrobial resistance, additional efforts are needed to develop innovative, rapid, accurate, and portable diagnostic tools for AST. The wide implementation of novel devices would enable the identification of the optimal treatment approaches and the surveillance of antibiotic resistance in health, agriculture, and the environment, allowing monitoring and better tackling the emergence of AMR.
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Gehring T, Kim HJ, Dibloni E, Neuenhoff M, Buechler C. Comparison of Antimicrobial Susceptibility Test Results of Disk Diffusion, Gradient Strip, and Automated Dilution with Broth Microdilution for Piperacillin-Tazobactam. Microb Drug Resist 2021; 27:1305-1311. [PMID: 34582726 DOI: 10.1089/mdr.2020.0011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In the treatment of septic patients, the prediction of a pathogen's susceptibility to piperacillin-tazobactam can be crucial. Commercial tests are available to measure the pathogen's susceptibility to piperacillin-tazobactam, but there is conflicting evidence regarding their accuracy. Therefore, this study compared the accuracy of disk diffusion, gradient strip, and automated dilution with the accepted standard broth microdilution. Testing was performed on 150 blood culture isolates from hospitalized patients at the University Hospital Bonn. The most recent Escherichia coli (n = 50), Klebsiella pneumoniae (n = 50), and Pseudomonas aeruginosa (n = 50) isolates were chosen. All measurements were performed strictly according to the manufacturer's instructions. Minimal inhibitory concentrations were primarily interpreted based on EUCAST (European Committee on Antimicrobial Susceptibility Testing) 8.1 and supplementarily based on CLSI (Clinical and Laboratory Standards Institute) 28th. The results of automated dilution showed a categorical agreement of 93.3% and presented five minor errors, four major errors, and one very major error. The results for gradient strip and disk diffusion were similar, except for the three additional major errors in the gradient strip and two additional very major errors in disk diffusion. Most of the major errors and very major errors were associated with P. aeruginosa. In conclusion, there was no relevant difference in accuracy between the three compared tests. Their overall categorical agreement ranged from 90.7% to 93.3% and was therefore at the lower end of the threshold. The possibly increased error rate for P. aeruginosa could be relevant in the preparation of empirical antibiotic guidelines and the treatment of septic patients. Universal Trial Number: U1111-1224-0035.
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Affiliation(s)
- Thomas Gehring
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Hyeon-June Kim
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Eliane Dibloni
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Marcel Neuenhoff
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
| | - Christian Buechler
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany
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Kuo SC, Tan MC, Huang WC, Wu HC, Chen FJ, Liao YC, Wang HY, Shiau YR, Lauderdale TL. Susceptibility of Elizabethkingia spp. to commonly tested and novel antibiotics and concordance between broth microdilution and automated testing methods. J Antimicrob Chemother 2021; 76:653-658. [PMID: 33258923 DOI: 10.1093/jac/dkaa499] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 10/27/2020] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES We aimed to determine susceptibilities of Elizabethkingia spp. to 25 commonly tested and 8 novel antibiotics, and to compare the performance of different susceptibility testing methods. METHODS Clinical isolates of Elizabethkingia spp., Chryseobacterium spp. and Flavobacterium spp. collected during 2002-18 (n = 210) in a nationwide surveillance programme in Taiwan were speciated by 16S rRNA sequencing. MICs were determined by broth microdilution. The broth microdilution results of 18 common antibiotics were compared with those obtained by the VITEK 2 automated system. RESULTS Among the Elizabethkingia spp. identified (n = 108), Elizabethkingia anophelis was the most prevalent (n = 90), followed by Elizabethkingia meningoseptica (n = 7) and Elizabethkingia miricola cluster [E. miricola (n = 6), Elizabethkingia bruuniana (n = 3) and Elizabethkingia ursingii (n = 2)]. Most isolates were recovered from respiratory or blood specimens from hospitalized, elderly patients. PFGE showed two major and several minor E. anophelis clones. All isolates were resistant to nearly all the tested β-lactams. Doxycycline, minocycline and trimethoprim/sulfamethoxazole inhibited >90% of Elizabethkingia spp. Rifampin inhibited E. meningoseptica (100%) and E. anophelis (81.1%). Fluoroquinolones and tigecycline were active against E. meningoseptica and E. miricola cluster isolates. Novel antibiotics, including imipenem/relebactam, meropenem/vaborbactam, ceftazidime/avibactam, cefepime/zidebactam, delafloxacin, eravacycline and omadacycline were ineffective but lascufloxacin inhibited half of Elizabethkingia spp. The very major discrepancy rates of VITEK 2 were >1.5% for ciprofloxacin, moxifloxacin and vancomycin. Major discrepancy rates were >3% for amikacin, tigecycline, piperacillin/tazobactam and trimethoprim/sulfamethoxazole. CONCLUSIONS MDR, absence of standard interpretation criteria and poor intermethod concordance necessitate working guidelines to facilitate future research of emerging Elizabethkingia spp.
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Affiliation(s)
- Shu-Chen Kuo
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Mei-Chen Tan
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Wei-Cheng Huang
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Han-Chieh Wu
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Feng-Jui Chen
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Yu-Chieh Liao
- Institute of Population Health Sciences, National Health Research Institutes, Miaoli, Taiwan
| | - Hui-Ying Wang
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Yih-Ru Shiau
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Tsai-Ling Lauderdale
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
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Performance of Antipseudomonal β-Lactams on the Accelerate PhenoTest BC Kit against a Collection of Pseudomonas aeruginosa Isolates. J Clin Microbiol 2021; 59:JCM.01781-20. [PMID: 33148710 PMCID: PMC8111152 DOI: 10.1128/jcm.01781-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Thi MTT, Wibowo D, Rehm BH. Pseudomonas aeruginosa Biofilms. Int J Mol Sci 2020; 21:ijms21228671. [PMID: 33212950 PMCID: PMC7698413 DOI: 10.3390/ijms21228671] [Citation(s) in RCA: 274] [Impact Index Per Article: 68.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/09/2020] [Accepted: 11/13/2020] [Indexed: 12/17/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic human pathogen causing devastating acute and chronic infections in individuals with compromised immune systems. Its highly notorious persistence in clinical settings is attributed to its ability to form antibiotic-resistant biofilms. Biofilm is an architecture built mostly by autogenic extracellular polymeric substances which function as a scaffold to encase the bacteria together on surfaces, and to protect them from environmental stresses, impedes phagocytosis and thereby conferring the capacity for colonization and long-term persistence. Here we review the current knowledge on P. aeruginosa biofilms, its development stages, and molecular mechanisms of invasion and persistence conferred by biofilms. Explosive cell lysis within bacterial biofilm to produce essential communal materials, and interspecies biofilms of P. aeruginosa and commensal Streptococcus which impedes P. aeruginosa virulence and possibly improves disease conditions will also be discussed. Recent research on diagnostics of P. aeruginosa infections will be investigated. Finally, therapeutic strategies for the treatment of P. aeruginosa biofilms along with their advantages and limitations will be compiled.
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Benkova M, Soukup O, Marek J. Antimicrobial susceptibility testing: currently used methods and devices and the near future in clinical practice. J Appl Microbiol 2020; 129:806-822. [DOI: 10.1111/jam.14704] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 04/28/2020] [Accepted: 05/11/2020] [Indexed: 12/17/2022]
Affiliation(s)
- M. Benkova
- Department of Epidemiology Faculty of Military Health Sciences University of Defence Hradec Kralove Czech Republic
- Biomedical Research Center University Hospital Hradec Kralove Hradec Kralove Czech Republic
| | - O. Soukup
- Biomedical Research Center University Hospital Hradec Kralove Hradec Kralove Czech Republic
- Department of Toxicology and Military Pharmacy Faculty of Military Health Sciences University of Defence Hradec Kralove Czech Republic
| | - J. Marek
- Department of Epidemiology Faculty of Military Health Sciences University of Defence Hradec Kralove Czech Republic
- Biomedical Research Center University Hospital Hradec Kralove Hradec Kralove Czech Republic
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Kidd TJ, Canton R, Ekkelenkamp M, Johansen HK, Gilligan P, LiPuma JJ, Bell SC, Elborn JS, Flume PA, VanDevanter DR, Waters VJ. Defining antimicrobial resistance in cystic fibrosis. J Cyst Fibros 2018; 17:696-704. [PMID: 30266518 DOI: 10.1016/j.jcf.2018.08.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/21/2018] [Accepted: 08/31/2018] [Indexed: 12/31/2022]
Abstract
Antimicrobial resistance (AMR) can present significant challenges in the treatment of cystic fibrosis (CF) lung infections. In CF and other chronic diseases, AMR has a different profile and clinical consequences compared to acute infections and this requires different diagnostic and treatment approaches. This review defines AMR, explains how it occurs, describes the methods used to measure AMR as well as their limitations, and concludes with future directions for research and development in the area of AMR in CF.
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Affiliation(s)
- Timothy J Kidd
- School of Chemistry and Molecular Biosciences, The University of Queensland, Lung Bacteria Group, QIMR Berghofer Medical Research Institute, Brisbane, Australia.
| | - Rafael Canton
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.
| | - Miquel Ekkelenkamp
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
| | - Helle Krogh Johansen
- Department of Clinical Microbiology, Rigshospitalet, Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
| | - Peter Gilligan
- Clinical Microbiology-Immunology Laboratories, UNC HealthCare, Chapel Hill, NC, USA.
| | - John J LiPuma
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Scott C Bell
- Department of Thoracic Medicine, The Prince Charles Hospital and QIMR Berghofer Medical Researhc Institute, Brisbane, Australia.
| | - J Stuart Elborn
- Imperial College and Royal Brompton Hospital, London, Queen's University Belfast, United Kingdom.
| | - Patrick A Flume
- Departments of Medicine and Pediatrics, Medical University of South Carolina, Charleston, SC, USA.
| | - Donald R VanDevanter
- Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
| | - Valerie J Waters
- Division of Infectious Diseases, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, USA.
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Costa-de-Oliveira S, Teixeira-Santos R, Silva AP, Pinho E, Mergulhão P, Silva-Dias A, Marques N, Martins-Oliveira I, Rodrigues AG, Paiva JA, Cantón R, Pina-Vaz C. Potential Impact of Flow Cytometry Antimicrobial Susceptibility Testing on the Clinical Management of Gram-Negative Bacteremia Using the FASTinov ® Kit. Front Microbiol 2017; 8:2455. [PMID: 29312169 PMCID: PMC5733032 DOI: 10.3389/fmicb.2017.02455] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 11/27/2017] [Indexed: 11/16/2022] Open
Abstract
Laboratory assessment of antimicrobial susceptibility is a prerequisite for adequate management of infections. The aim of this research was to evaluate the performance of the novel FASTinov® kit for antimicrobial susceptibility testing (AST) of Gram negative bacilli directly on positive blood cultures. One hundred and two positive blood cultures from patients of a Portuguese University Hospital were included. AST were performed with routine method, Vitek2, with FASTinov® kit, and with the gold standard microdilution. Bacteria directly extracted from blood cultures were used to inoculate the FASTinov® kit. Time-to-result as well as the number of patients receiving initially inappropriate therapy (and those in whom de-escalation would have been done) and length of stay (LOS) was recorded. Seventy percent of patients were over 70 years old and 18.6% were admitted in intensive care units. Regarding the isolates, 88.2% were Enterobacteriaceae, 9.8% Pseudomonas spp. and 1% Acinetobacter spp. Extended spectrum β-lactamases producing-Enterobacteriaceae were found in 7.8% of cases and 10.8% were multi-drug resistant. Fifty-one hours was the mean of time-to-result for routine test (Vitek2) vs. 2 h response regarding Fastinov® test. The overall agreement between FASTinov® and the reference microdilution method was 98%. According to the susceptibility phenotype, 16.7% of patients received initially inappropriate therapy and the mean hospital LOS of these patients was significantly higher. FASTinov® kit revealed an excellent correlation with the AST standard method and provided much earlier results than Vitek2.
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Affiliation(s)
- Sofia Costa-de-Oliveira
- Division of Microbiology, Department of Pathology, Faculty of Medicine, University of Porto, Porto, Portugal.,CINTESIS - Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal.,FASTinov, S.A., Matosinhos, Portugal
| | - Rita Teixeira-Santos
- Division of Microbiology, Department of Pathology, Faculty of Medicine, University of Porto, Porto, Portugal.,FASTinov, S.A., Matosinhos, Portugal
| | - Ana P Silva
- Division of Microbiology, Department of Pathology, Faculty of Medicine, University of Porto, Porto, Portugal.,CINTESIS - Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Elika Pinho
- Department of Emergency and Intensive Care, Centro Hospitalar Sao Joao, Porto, Portugal
| | - Paulo Mergulhão
- Department of Emergency and Intensive Care, Centro Hospitalar Sao Joao, Porto, Portugal.,Department of Medicine, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Ana Silva-Dias
- CINTESIS - Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal.,FASTinov, S.A., Matosinhos, Portugal
| | | | | | - Acácio G Rodrigues
- Division of Microbiology, Department of Pathology, Faculty of Medicine, University of Porto, Porto, Portugal.,CINTESIS - Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal.,FASTinov, S.A., Matosinhos, Portugal
| | - José A Paiva
- Department of Emergency and Intensive Care, Centro Hospitalar Sao Joao, Porto, Portugal.,Department of Medicine, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Rafael Cantón
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria, Madrid, Spain
| | - Cidália Pina-Vaz
- Division of Microbiology, Department of Pathology, Faculty of Medicine, University of Porto, Porto, Portugal.,CINTESIS - Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal.,FASTinov, S.A., Matosinhos, Portugal
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14
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Hirabayashi A, Kato D, Tomita Y, Iguchi M, Yamada K, Kouyama Y, Morioka H, Tetsuka N, Yagi T. Risk factors for and role of OprD protein in increasing minimal inhibitory concentrations of carbapenems in clinical isolates of Pseudomonas aeruginosa. J Med Microbiol 2017; 66:1562-1572. [PMID: 28984565 DOI: 10.1099/jmm.0.000601] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
PURPOSE This study examined the risk factors for, and molecular mechanisms underlying, the increase in carbapenem minimum inhibitory concentrations (MICs) in clinical isolates of Pseudomonas aeruginosa. METHODOLOGY Consecutive clinical isolates of P. aeruginosa were collected. The MicroScan WalkAway system detected more than fourfold increases in the MICs of carbapenems in P. aeruginosa isolates serially recovered from some patients during their clinical course. The clinical risk factors associated with this increase were examined by multiple logistic regression analysis. Western blot analysis and nucleotide sequencing of the oprD gene of 19 clonally related and paired P. aeruginosa isolates from the same patients were undertaken to examine the mechanisms underlying the increase in MICs. RESULTS The results showed that prior use of carbapenems (OR, 2.799; 95 % CI, 1.088-7.200; P=0.033) and the use of ventilators or tracheostomies (OR, 2.648; 95 % CI, 1.051-6.671; P=0.039) were risk factors for increased carbapenem MICs. Analysis of the underlying mechanisms revealed that loss of functional OprD protein due to mutation of the oprD gene tended to occur in P. aeruginosa isolates with imipenem MICs of more than 8 µg ml-1; a reduction in OprD expression was observed in P. aeruginosa isolates with imipenem MICs of 4 or 8 µg ml-1. This difference in the resistance mechanism was not correlated with the MICs of meropenem. CONCLUSION This difference in the resistance mechanism of P. aeruginosa indicates a critical breakpoint at an imipenem MIC of 8 µg ml-1, in accordance with EUCAST criteria. Reducing carbapenem use will prevent P. aeruginosa clinical isolates from developing resistance to carbapenems.
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Affiliation(s)
- Aki Hirabayashi
- Department of Infectious Diseases, Nagoya University Hospital, Nagoya, Aichi, Japan.,Department of Infectious Diseases, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Daizo Kato
- Department of Infectious Diseases, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Yuka Tomita
- Department of Infectious Diseases, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Mitsutaka Iguchi
- Department of Infectious Diseases, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Keiko Yamada
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Yuichi Kouyama
- Department of Hospital Pharmacy, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Hiroshi Morioka
- Department of Infectious Diseases, Nagoya University Hospital, Nagoya, Aichi, Japan.,Department of Infectious Diseases, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Nobuyuki Tetsuka
- Department of Infectious Diseases, Nagoya University Hospital, Nagoya, Aichi, Japan.,Department of Infectious Diseases, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Tetsuya Yagi
- Department of Infectious Diseases, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan.,Department of Infectious Diseases, Nagoya University Hospital, Nagoya, Aichi, Japan
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15
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Pseudomonas Endocarditis with an unstable phenotype: the challenges of isolate characterization and Carbapenem stewardship with a partial review of the literature. Antimicrob Resist Infect Control 2017; 6:87. [PMID: 28855980 PMCID: PMC5574246 DOI: 10.1186/s13756-017-0245-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 08/20/2017] [Indexed: 01/11/2023] Open
Abstract
Background Pseudomonas endocarditis is exceedingly rare, especially in patients without predisposing risks. We present such a case that included unexpected switches in antibacterial resistance profiles in two Pseudomonas aeruginosa (PA) strains with the same whole-genome sequence. The case also involved diagnostic and treatment challenges, such as issues with automated testing platforms, choosing the optimal aminoglycoside, minimizing unnecessary carbapenem exposure, and the need for faster, more informative laboratory tests. Case presentation On hospital day one (HD-1) a cefepime and piperacillin-tazobactam (FEP-TZP)-susceptible P. aeruginosa was isolated from the bloodstream of a 62-year-old man admitted for evaluation of possible endocarditis and treated with gentamicin and cefepime. On HD-2, his antibiotic regimen was changed to tobramycin and cefepime. On HD-11, he underwent aortic valve replacement, and P. aeruginosa was isolated from the explanted valve. Unexpectedly, it was FEP-TZP-resistant, so cefepime was switched to meropenem. On HD-14, in preparation for whole-genome sequencing (WGS), valve and blood isolates were removed from cryo-storage, re-cultured, and simultaneously tested with the same platforms, reagents, and inoculations previously used. Curiously, the valve isolate was now FEP-TZP-susceptible. WGS revealed that both isolates were phylogenetically identical, differing by a single nucleotide in a chemotaxis-encoding gene. They also contained the same resistance genes (blaADC35, aph(3′)-II, blaOXA-50, catB7, fosA). Conclusion Repeated testing on alternate platforms and WGS did not definitively determine the resistance mechanism(s), which in this case, is most likely unstable de-repression of a chromosomal AmpC β-lactamase, porin alterations, or efflux upregulation, with reversion to baseline (non-efflux) transcription. Although sub-culture on specialized media to select for less fit (more resistant) colonies, followed by transcriptome analysis, and multiple sequence alignment, might have revealed the mechanism and better informed the optimal choice of β-lactam, such approaches are neither rapid, nor feasible for hospital laboratories. In this era of escalating drug resistance and dwindling antibiotics, use of the most potent anti-pseudomonals must be balanced with stewardship. Clinicians need access to validated genomic correlates of resistance, and faster, more informative diagnostics. Therefore, we placed these isolates and their sequences in the public domain for inclusion in the Pseudomonas pan-genome and database projects for further countermeasure development.
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16
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Stefani S, Campana S, Cariani L, Carnovale V, Colombo C, Lleo MM, Iula VD, Minicucci L, Morelli P, Pizzamiglio G, Taccetti G. Relevance of multidrug-resistant Pseudomonas aeruginosa infections in cystic fibrosis. Int J Med Microbiol 2017; 307:353-362. [PMID: 28754426 DOI: 10.1016/j.ijmm.2017.07.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 01/15/2023] Open
Abstract
Multidrug-resistant (MDR) Pseudomonas aeruginosa is an important issue for physicians who take care of patients with cystic fibrosis (CF). Here, we review the latest research on how P. aeruginosa infection causes lung function to decline and how several factors contribute to the emergence of antibiotic resistance in P. aeruginosa strains and influence the course of the infection course. However, many aspects of the practical management of patients with CF infected with MDR P. aeruginosa are still to be established. Less is known about the exact role of susceptibility testing in clinical strategies for dealing with resistant infections, and there is an urgent need to find a tool to assist in choosing the best therapeutic strategy for MDR P. aeruginosa infection. One current perception is that the selection of antibiotic therapy according to antibiogram results is an important component of the decision-making process, but other patient factors, such as previous infection history and antibiotic courses, also need to be evaluated. On the basis of the known issues and the best current data on respiratory infections caused by MDR P. aeruginosa, this review provides practical suggestions to optimize the diagnostic and therapeutic management of patients with CF who are infected with these pathogens.
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Affiliation(s)
- S Stefani
- Department of Biomedical and Biotechnological Sciences, Division of Microbiology, University of Catania, Catania, Italy.
| | - S Campana
- Department of Paediatric Medicine, Cystic Fibrosis Centre, Anna Meyer Children's University Hospital, Florence, Italy
| | - L Cariani
- Cystic Fibrosis Microbiology Laboratory, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - V Carnovale
- Department of Translational Medical Sciences, Cystic Fibrosis Center, University "Federico II", Naples, Italy
| | - C Colombo
- Cystic Fibrosis Center, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - M M Lleo
- Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - V D Iula
- Department of Molecular Medicine and Medical Biotechnology, Federico II University Medical School, Naples, Italy
| | - L Minicucci
- Microbiology Laboratory, Cystic Fibrosis Center, G. Gaslini Institute, Genoa, Italy
| | - P Morelli
- Department of Paediatric, Cystic Fibrosis Center, G. Gaslini Institute, Genoa, Italy
| | - G Pizzamiglio
- Respiratory Disease Department, Cystic Fibrosis Center Adult Section, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico Milano, Milan, Italy
| | - G Taccetti
- Department of Paediatric Medicine, Cystic Fibrosis Centre, Anna Meyer Children's University Hospital, Florence, Italy
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17
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Detection of Piperacillin-Tazobactam-Resistant/Pan-β-Lactam-Susceptible Escherichia coli with Current Automated Susceptibility Test Systems. Infect Control Hosp Epidemiol 2017; 38:379-380. [PMID: 28069100 DOI: 10.1017/ice.2016.325] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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18
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E. BEATRICEHERVÉ. NUEVAS TECNOLOGÍAS EN DIAGNÓSTICO MICROBIOLÓGICO: AUTOMATIZACIÓN Y ALGUNAS APLICACIONES EN IDENTIFICACIÓN MICROBIANA Y ESTUDIO DE SUSCEPTIBILIDAD. REVISTA MÉDICA CLÍNICA LAS CONDES 2015. [DOI: 10.1016/j.rmclc.2015.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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19
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Lubbers BV, Turnidge J. Antimicrobial susceptibility testing for bovine respiratory disease: Getting more from diagnostic results. Vet J 2015; 203:149-54. [DOI: 10.1016/j.tvjl.2014.12.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 09/25/2014] [Accepted: 12/09/2014] [Indexed: 12/23/2022]
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20
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Choi J, Yoo J, Lee M, Kim EG, Lee JS, Lee S, Joo S, Song SH, Kim EC, Lee JC, Kim HC, Jung YG, Kwon S. A rapid antimicrobial susceptibility test based on single-cell morphological analysis. Sci Transl Med 2014; 6:267ra174. [DOI: 10.1126/scitranslmed.3009650] [Citation(s) in RCA: 201] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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21
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Assessment of microbiological diagnostic procedures for respiratory specimens from cystic fibrosis patients in German laboratories by use of a questionnaire. J Clin Microbiol 2014; 52:977-9. [PMID: 24391197 DOI: 10.1128/jcm.02866-13] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Respiratory specimens from cystic fibrosis (CF) patients challenge microbiological laboratories with their complexity of pathogens and atypical variants. We evaluated the diagnostic procedures in German laboratories by use of a questionnaire. Although most laboratories followed guidelines, some of them served only a small number of patients, while others did not use the recommended selective agars to culture the particular CF-relevant species.
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22
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Juan C, Conejo MC, Tormo N, Gimeno C, Pascual Á, Oliver A. Challenges for accurate susceptibility testing, detection and interpretation of β-lactam resistance phenotypes in Pseudomonas aeruginosa: results from a Spanish multicentre study. J Antimicrob Chemother 2012; 68:619-30. [PMID: 23143898 DOI: 10.1093/jac/dks439] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVES To evaluate the proficiency of Spanish laboratories regarding accurate susceptibility testing, detection and interpretation of Pseudomonas aeruginosa β-lactam resistance phenotypes. METHODS Thirteen characterized strains were sent to 54 participating centres: clinical strains producing horizontally acquired β-lactamases [extended-spectrum β-lactamases (ESBLs; PER-1 and OXA-161) and class A (GES-5) and B (VIM-2) carbapenemases] and mutants with combinations of chromosomal mechanisms (AmpC, OprD and/or efflux). The centres were requested to evaluate six antipseudomonal β-lactams, provide raw/interpreted clinical categories and detect/infer the resistance mechanisms. Consensus results from reference centres were used to assign minor, major or very major errors (mEs, MEs or VMEs). RESULTS Vitek2, MicroScan WalkAway and Wider were the most used devices (25%-30% each). CLSI/EUCAST breakpoints were used in 86%/14% of the determinations. Discrepancies exclusively due to the differential application of breakpoints were highest for aztreonam, followed by piperacillin/tazobactam. The lowest percentage of VMEs was for Vitek2, followed by Wider. The highest percentages of VMEs (6%) were for the AmpC-hyperproducing OprD(-) strain and for the GES-5 producer, while among antibiotics the highest percentage of VMEs (22%) involved piperacillin/tazobactam. Appropriate inference of resistance mechanisms was high for the VIM-2-producing strain (83%), but low (<40%) for strains producing ESBLs or non-metallo-β-lactamase carbapenemases. CONCLUSIONS The use of different breakpoints and devices, the complexity of mutation-driven resistance mechanisms and the lack of unequivocal tests to detect ESBLs or carbapenemases in P. aeruginosa leads to extraordinary variability and low accuracy in susceptibility testing, which may have consequences for the treatment and control of nosocomial infections.
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Affiliation(s)
- Carlos Juan
- Servicio de Microbiología, Hospital Son Espases, Palma de Mallorca, Spain
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23
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Duggal S, Gaind R, Tandon N, Deb M, Chugh TD. Comparison of an automated system with conventional identification and antimicrobial susceptibility testing. ISRN MICROBIOLOGY 2012; 2012:107203. [PMID: 23762748 PMCID: PMC3664201 DOI: 10.5402/2012/107203] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 08/23/2012] [Indexed: 11/23/2022]
Abstract
The present study was designed to compare a fully automated identification/antibiotic susceptibility testing (AST) system BD Phoenix (BD) for its efficacy in rapid and accurate identification and AST with conventional manual methods and to determine if the errors reported in AST, such as the (very major errors) VME (false susceptibility), (major errors) ME (false resistance), and (minor errors) MiE (intermediate category interpretation) were within the range certified by FDA. Identification and antimicrobial susceptibility test results of eighty-five clinical isolates including both gram-positive and negative were compared on Phoenix considering the results obtained from conventional manual methods of identification and disc diffusion testing of antibiotics as standards for comparison. Phoenix performed favorably well. There was 100% concordance in identification for gram-negative isolates and 94.83% for gram-positive isolates. In seven cases, Phoenix proved better than conventional identification. For antibiotic results, categorical agreement was 98.02% for gram-positive and 95.7% for gram-negative isolates. VME was 0.33%, ME 0.66%, MiE 0.99% for gram-positive isolates and 1.23% VME, 1.23% ME, and 1.85% MiE for gram-negative isolates. Therefore, this automated system can be used as a tool to facilitate early identification and susceptibility pattern of aerobic bacteria in routine microbiology laboratories.
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Affiliation(s)
- Shalini Duggal
- Department of Microbiology, Dr. Baba Saheb Ambedkar Hospital, Rohini, New Delhi 110085, India
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24
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Esquisabel AC, Rodríguez M, Campo-Sosa A, Rodríguez C, Martínez-Martínez L. Mechanisms of resistance in clinical isolates of Pseudomonas aeruginosa less susceptible to cefepime than to ceftazidime. Clin Microbiol Infect 2011; 17:1817-22. [DOI: 10.1111/j.1469-0691.2011.03530.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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25
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Jin WY, Jang SJ, Lee MJ, Park G, Kim MJ, Kook JK, Kim DM, Moon DS, Park YJ. Evaluation of VITEK 2, MicroScan, and Phoenix for identification of clinical isolates and reference strains. Diagn Microbiol Infect Dis 2011; 70:442-7. [PMID: 21767700 DOI: 10.1016/j.diagmicrobio.2011.04.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 04/18/2011] [Accepted: 04/29/2011] [Indexed: 11/25/2022]
Abstract
To compare the identification accuracies of VITEK 2 (bioMérieux), MicroScan (Siemens Healthcare), and Phoenix (Becton Dickinson), microbial identification was performed on 160 clinical isolates and 50 reference strains on each of these 3 systems, using the appropriate identification kit provided by each system. Of the 142 clinical isolates that were identified at the species level, VITEK 2, MicroScan, and Phoenix correctly identified 93.7%, 82.4%, and 93.0%, and incorrectly identified 2.1%, 7.0%, and 0%, respectively. In the reference strain tests, VITEK 2, MicroScan, and Phoenix correctly identified 55.3%, 54.4%, and 78.0% of the reference strains at the species level and incorrectly identified 10.6%, 13.0%, and 6.0% of the reference strains, respectively. In conclusion, the identification rate of VITEK 2, Phoenix, and MicroScan was high or acceptable on clinical isolates. Phoenix showed a significantly higher performance than VITEK 2 or MicroScan in identifying the reference strains.
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Affiliation(s)
- Won-Young Jin
- Department of Laboratory Medicine, Chosun University Medical School, Gwang-Ju, South Korea
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26
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Mérens A, Delacour H, Plésiat P, Cavallo JD, Jeannot K. Pseudomonas aeruginosa et résistance aux antibiotiques. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/s1773-035x(11)71102-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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27
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Abstract
Long bone osteomyelitis presents a variety of challenges to the physician. The severity of the disease is staged depending upon the infection's particular features, including its etiology, pathogenesis, extent of bone involvement, duration, and host factors particular to the individual patient (infant, child, adult, or immunocompromised). Long bone osteomyelitis may be either hematogenous or caused by a contiguous spread of infection. A single pathogenic organism is almost always recovered from the bone in hematogenous osteomyelitis; Staphylococcus aureus is the most common organism isolated. A variety of multidrug-resistant organisms of bacteria continue to be a source of concern in arresting infection. The primary weapons to treat these infections are culture-specific antibiotics, aggressive debridement, muscle flaps, and bone grafts. This article offers a basic review of the classification, etiology, epidemiology, pathogenesis, and treatment of long bone osteomyelitis.
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Evaluation of an automated system for the detection of carbapenem resistant Acinetobacter baumannii and assessment of metallo-β-lactamase production using two different phenotyping methods. J Microbiol Methods 2011; 86:121-3. [DOI: 10.1016/j.mimet.2011.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 04/13/2011] [Accepted: 04/14/2011] [Indexed: 11/21/2022]
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Jekarl DW, Han SB, Kim YJ, Shin SH, Park KG, Park JJ, Han K, Park YJ. Evaluation of Vitek2 and BD Phoenix in antimicrobial susceptibility testing of Acinetobacter baumannii and Pseudomonas aeruginosa. Diagn Microbiol Infect Dis 2010; 67:384-6. [PMID: 20638609 DOI: 10.1016/j.diagmicrobio.2010.02.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 02/22/2010] [Accepted: 02/27/2010] [Indexed: 11/15/2022]
Abstract
The accuracy of antimicrobial susceptibility testing of Vitek2 and BD Phoenix against Acinetobacter baumannii and Pseudomonas aeruginosa was evaluated. Both systems showed overall categoric agreement of < or =90% for cefepime and ceftazidime against A. baumannii and imipenem and cefepime (and ceftazidime with Vitek2) against P. aeruginosa because of high minor error rates.
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Affiliation(s)
- Dong Wook Jekarl
- Department of Laboratory Medicine, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, 137-701, Republic of Korea
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Horii T, Adachi A, Morita M. Detection of carbapenem resistance in clinical mucoid Pseudomonas aeruginosa isolates. ACTA ACUST UNITED AC 2010; 41:873-6. [PMID: 19922072 DOI: 10.3109/00365540903186199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Of 19 isolates of mucoid Pseudomonas aeruginosa, 2 isolates showed imipenem resistance conferred by reduced OprD production. Imipenem resistance was detected by the MicroScan broth microdilution and Etest methods, but minimum inhibitory concentrations could not be determined by the Vitek system for an isolate. In cases where susceptibility cannot be determined by the broth microdilution methods, Etest results would be valuable for effective treatment.
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Affiliation(s)
- Toshinobu Horii
- Department of Microbiology and Immunology, School of Medicine, Tottori University Faculty of Medicine, Yonago, Japan.
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31
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Kuper KM, Boles DM, Mohr JF, Wanger A. Antimicrobial Susceptibility Testing: A Primer for Clinicians. Pharmacotherapy 2009; 29:1326-43. [DOI: 10.1592/phco.29.11.1326] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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32
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Validation of Vitek 2 nonfermenting gram-negative cards and Vitek 2 version 4.02 software for identification and antimicrobial susceptibility testing of nonfermenting gram-negative rods from patients with cystic fibrosis. J Clin Microbiol 2009; 47:3283-8. [PMID: 19710272 DOI: 10.1128/jcm.00505-09] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Accurate identification and antimicrobial susceptibility testing (AST) of nonfermenters from cystic fibrosis patients are essential for appropriate antimicrobial treatment. This study examined the ability of the newly designed Vitek 2 nonfermenting gram-negative card (NGNC) (new gram-negative identification card; bioMérieux, Marcy-l'Etoile, France) to identify nonfermenting gram-negative rods from cystic fibrosis patients in comparison to reference methods and the accuracy of the new Vitek 2 version 4.02 software for AST compared to the broth microdilution method. Two hundred twenty-four strains for identification and 138 strains for AST were investigated. The Vitek 2 NGNC identified 211 (94.1%) of the nonfermenters correctly. Among morphologically atypical microorganisms, five strains were misidentified and eight strains were determined with low discrimination, requiring additional tests which raised the correct identification rate to 97.8%. Regarding AST, the overall essential agreement of Vitek 2 was 97.6%, and the overall categorical agreement was 92.9%. Minor errors were found in 5.1% of strains, and major and very major errors were found in 1.6% and 0.3% of strains, respectively. In conclusion, the Vitek NGNC appears to be a reliable method for identification of morphologically typical nonfermenters and is an improvement over the API NE system and the Vitek 2 GNC database version 4.01. However, classification in morphologically atypical nonfermenters must be interpreted with care to avoid misidentification. Moreover, the new Vitek 2 version 4.02 software showed good results for AST and is suitable for routine clinical use. More work is needed for the reliable testing of strains whose MICs are close to the breakpoints.
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33
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Torres E, Villanueva R, Bou G. Comparison of different methods of determining β-lactam susceptibility in clinical strains of Pseudomonas aeruginosa. J Med Microbiol 2009; 58:625-629. [DOI: 10.1099/jmm.0.005587-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
One hundred and one randomly selected (2003–2005) clinical isolates ofPseudomonas aeruginosawere used to assess the quantitative (MIC) and qualitative (susceptibility category) agreement between the microdilution broth reference method (RM) and disc diffusion (DD), Etest and the VITEK 2 automated susceptibility test system for determination of the susceptibility ofP. aeruginosato piperacillin (PIP), PIP–tazobactam (TZP), ceftazidime (CAZ), aztreonam (ATM) cefepime (FEP) and imipenem (IMP). The results obtained by the RM were compared with those obtained by the other methods. The RM and DD were performed according to CLSI criteria. Etest and VITEK 2 were according to the manufacturer's instructions. The Advanced Expert System (AES), which interprets MICs generated by VITEK 2, was modified with new rules of interpretation. Overall, VITEK 2 showed the lowest MIC90values for the six antibiotics. The RM categorical testing (susceptibility and resistance) rates withP. aeruginosawere 11.8 and 88.1 for PIP, 22.7 and 77.2 for TZP, 14.8 and 78.2 for CAZ, 12.8 and 54.4 for ATM, 16.8 and 75.3 for FEP, and 7.9 and 90.1 for IMP, respectively. Very major errors (false susceptible) were only detected for ATM and FEP with DD and for IMP with three methods. Major errors (false resistant) were generally acceptable for all antibiotics except TZP. VITEK 2 yielded a high level of minor errors (trends toward false susceptibility), mainly with CAZ and FEP. A good agreement was obtained for all antibiotics/methods assayed, thus highlighting the importance of the AES for categorization ofβ-lactam susceptibility inP. aeruginosa.
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Affiliation(s)
- Eva Torres
- Servicio de Microbiología – Unidad de Investigación, Complejo Hospitalario Universitario Juan Canalejo, La Coruña, Spain
| | - Rosa Villanueva
- Servicio de Microbiología – Unidad de Investigación, Complejo Hospitalario Universitario Juan Canalejo, La Coruña, Spain
| | - Germán Bou
- Servicio de Microbiología – Unidad de Investigación, Complejo Hospitalario Universitario Juan Canalejo, La Coruña, Spain
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Detecting imipenem resistance in Acinetobacter baumannii by automated systems (BD Phoenix, Microscan WalkAway, Vitek 2); high error rates with Microscan WalkAway. BMC Infect Dis 2009; 9:30. [PMID: 19291298 PMCID: PMC2664816 DOI: 10.1186/1471-2334-9-30] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Accepted: 03/16/2009] [Indexed: 11/10/2022] Open
Abstract
Background Increasing reports of carbapenem resistant Acinetobacter baumannii infections are of serious concern. Reliable susceptibility testing results remains a critical issue for the clinical outcome. Automated systems are increasingly used for species identification and susceptibility testing. This study was organized to evaluate the accuracies of three widely used automated susceptibility testing methods for testing the imipenem susceptibilities of A. baumannii isolates, by comparing to the validated test methods. Methods Selected 112 clinical isolates of A. baumanii collected between January 2003 and May 2006 were tested to confirm imipenem susceptibility results. Strains were tested against imipenem by the reference broth microdilution (BMD), disk diffusion (DD), Etest, BD Phoenix, MicroScan WalkAway and Vitek 2 automated systems. Data were analysed by comparing the results from each test method to those produced by the reference BMD test. Results MicroScan performed true identification of all A. baumannii strains while Vitek 2 unidentified one strain, Phoenix unidentified two strains and misidentified two strains. Eighty seven of the strains (78%) were resistant to imipenem by BMD. Etest, Vitek 2 and BD Phoenix produced acceptable error rates when tested against imipenem. Etest showed the best performance with only two minor errors (1.8%). Vitek 2 produced eight minor errors(7.2%). BD Phoenix produced three major errors (2.8%). DD produced two very major errors (1.8%) (slightly higher (0.3%) than the acceptable limit) and three major errors (2.7%). MicroScan showed the worst performance in susceptibility testing with unacceptable error rates; 28 very major (25%) and 50 minor errors (44.6%). Conclusion Reporting errors for A. baumannii against imipenem do exist in susceptibility testing systems. We suggest clinical laboratories using MicroScan system for routine use should consider using a second, independent antimicrobial susceptibility testing method to validate imipenem susceptibility. Etest, whereever available, may be used as an easy method to confirm imipenem susceptibility.
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Habib Babay HA, Manneh K, Somily AM. Accuracy of Detecting Resistance to Carbapenems among Gram Negative Rods: Comparison of Three Methods. J Taibah Univ Med Sci 2009. [DOI: 10.1016/s1658-3612(09)70081-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Wiegand I, Hilpert K, Hancock REW. Agar and broth dilution methods to determine the minimal inhibitory concentration (MIC) of antimicrobial substances. Nat Protoc 2008; 3:163-75. [PMID: 18274517 DOI: 10.1038/nprot.2007.521] [Citation(s) in RCA: 3411] [Impact Index Per Article: 213.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The aim of broth and agar dilution methods is to determine the lowest concentration of the assayed antimicrobial agent (minimal inhibitory concentration, MIC) that, under defined test conditions, inhibits the visible growth of the bacterium being investigated. MIC values are used to determine susceptibilities of bacteria to drugs and also to evaluate the activity of new antimicrobial agents. Agar dilution involves the incorporation of different concentrations of the antimicrobial substance into a nutrient agar medium followed by the application of a standardized number of cells to the surface of the agar plate. For broth dilution, often determined in 96-well microtiter plate format, bacteria are inoculated into a liquid growth medium in the presence of different concentrations of an antimicrobial agent. Growth is assessed after incubation for a defined period of time (16-20 h) and the MIC value is read. This protocol applies only to aerobic bacteria and can be completed in 3 d.
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Affiliation(s)
- Irith Wiegand
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, 2259 Lower Mall Research Station, Vancouver, British Columbia, V6T 1Z4, Canada
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Abstract
An accurate, appropriately collated antibiogram represents an integral resource for health care providers when assessing bacterial resistance and guiding antimicrobial selection and formulary decisions. Interpretation of bacterial susceptibility statistics is problematic yet frequent and unrecognized pitfalls may be avoided by following the M39-A2 guidelines to ensure correct analysis and presentation of cumulative antimicrobial susceptibility test data. This review addresses guideline recommendations related to antibiogram development, CLSI breakpoint interpretation, antimicrobial inclusion decisions, and the avoidance of duplicate and surveillance isolates. Unit-specific antibiograms in critical care units is encouraged for differentiation between hospital-wide ecology and these specific areas harboring more resistant pathogens. Antibiograms cannot track the emergence of microbial resistance during therapy and discrepancies exist between automated microbiology surveillance systems and their agreement with manual surveillance methods. When striving to improve overall patient outcomes, the use of a well-produced and disseminated antibiogram helps guide clinical decision making for patients requiring antimicrobial therapy.
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Affiliation(s)
- Edward H. Eiland
- Department of Pharmacy, Huntsville Hospital, Huntsville, Alabama,
| | | | - William Lindgren
- Department of Microbiology, Huntsville Hospital, Huntsville, Alabama
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Detection of virulence factors in Pseudomonas aeruginosa strains isolated from contact lens-associated corneal ulcers. Cornea 2008; 27:320-6. [PMID: 18362661 DOI: 10.1097/ico.0b013e31815c5a3f] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE In microbial keratitis associated with contact lens use, Pseudomonas is the most common etiologic agent. The purpose of this study was to report on the microbiological findings of 8 P. aeruginosa strains isolated from contact lens-associated corneal ulcers. METHODS Scrapings from contact lens-related corneal ulcers were inoculated for culture. Identification and antibiotic susceptibility testing were performed by using the Vitek system (bioMérieux). The Pseudomonas' ability to form biofilm; produce gelatinase, elastase, and alkaline protease; and adhere to and invade human corneal epithelial cells was studied. Polymerase chain reaction with enterobacterial repetitive intergenic consensus primers (ERIC-PCR) was used to establish clonal relationship between the different isolates. RESULTS All the strains showed multiple antibiotic resistance (resistance to 4 or more antibiotics), but all were susceptible to aminoglycosides and fluoroquinolones. Biofilm production was weak in 5 cases and absent in the remaining 3 cases. All isolates were able to produce alkaline protease and gelatinase but not elastase. Adherence to human corneal epithelial cells was poor (0-15 bacteria/cell) in 5 cases and medium (16-60 bacteria/cell) in 3 cases. Five isolates were found to be efficient invaders (>1000 CFU/mL). ERIC-PCR showed 8 different genetic patterns. CONCLUSIONS Because multiresistant Pseudomonas isolates are common, we recommend antibiotic susceptibility testing in all cases of Pseudomonas keratitis so that, if there is no response to initial empiric treatment, antibiotics can be modified according to susceptibility results. The ability to produce alkaline protease and gelatinase and invade the corneal epithelium may play a major role in the pathogenesis of contact lens-related P. aeruginosa keratitis. Also, ERIC-PCR seems to be an inexpensive, fast, reproducible, and discriminatory DNA typing tool for effective epidemiologic surveillance of P. aeruginosa isolates potentially transmissible between patients with ocular infections.
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Performance of Vitek 2 in antimicrobial susceptibility testing of Pseudomonas aeruginosa isolates with different mechanisms of beta-lactam resistance. J Clin Microbiol 2008; 46:2095-8. [PMID: 18434562 DOI: 10.1128/jcm.02216-07] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A total of 78 isolates of Pseudomonas aeruginosa grouped according to the phenotype for ceftazidime and imipenem susceptibility/resistance were used to assess the accuracy of the Vitek 2 system in antimicrobial susceptibility testing. Comparisons were made with a MIC gradient test for piperacillin-tazobactam, ceftazidime, aztreonam, imipenem, meropenem, gentamicin, and ciprofloxacin. For the total of 546 isolate-antimicrobial combinations tested, the category agreement was 83.6%, with 2.0, 1.6, and 12.8% very major, major, and minor errors, respectively. Vitek 2 accuracy was influenced differently by the mechanism responsible for resistance, and interpretation of the results in relation to phenotype could improve the performance of the system.
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Pseudomonas aeruginosa : résistance et options thérapeutiques à l’aube du deuxième millénaire. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/s1294-5501(07)91378-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tan TY, Ng LSY, Poh K. Susceptibility testing of unconventional antibiotics against multiresistant Acinetobacter spp. by agar dilution and Vitek 2. Diagn Microbiol Infect Dis 2007; 58:357-61. [PMID: 17467946 DOI: 10.1016/j.diagmicrobio.2007.02.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2006] [Revised: 02/06/2007] [Accepted: 02/11/2007] [Indexed: 10/23/2022]
Abstract
Treatment options are increasingly limited for carbapenem-resistant Acinetobacter baumannii. This study set out to determine the in vitro susceptibility of multiresistant Acinetobacter spp. to colistin, minocycline, and rifampicin using agar dilution, and to compare the accuracy of testing results obtained from an automated susceptibility testing system (Vitek 2). MICs for colistin, minocycline, and rifampicin were obtained by agar dilution and Vitek 2 for 44 unrelated strains of multiresistant Acinetobacter spp. All tested strains were susceptible to colistin, whereas 61% were susceptible to minocycline and 52% were susceptible to rifampicin. Results for colistin testing showed categoric agreement between Vitek 2 and agar dilution, with no false-resistance reported by Vitek 2. However, there was a poor agreement for minocycline and rifampicin when results obtained from Vitek 2 testing were compared with those obtained by agar dilution.
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Affiliation(s)
- Thean Yen Tan
- Laboratory Medicine Services, Changi General Hospital, Singapore 529889, Singapore.
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Mesaros N, Nordmann P, Plésiat P, Roussel-Delvallez M, Van Eldere J, Glupczynski Y, Van Laethem Y, Jacobs F, Lebecque P, Malfroot A, Tulkens PM, Van Bambeke F. Pseudomonas aeruginosa: resistance and therapeutic options at the turn of the new millennium. Clin Microbiol Infect 2007; 13:560-78. [PMID: 17266725 DOI: 10.1111/j.1469-0691.2007.01681.x] [Citation(s) in RCA: 384] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pseudomonas aeruginosa is a major cause of nosocomial infections. This organism shows a remarkable capacity to resist antibiotics, either intrinsically (because of constitutive expression of beta-lactamases and efflux pumps, combined with low permeability of the outer-membrane) or following acquisition of resistance genes (e.g., genes for beta-lactamases, or enzymes inactivating aminoglycosides or modifying their target), over-expression of efflux pumps, decreased expression of porins, or mutations in quinolone targets. Worryingly, these mechanisms are often present simultaneously, thereby conferring multiresistant phenotypes. Susceptibility testing is therefore crucial in clinical practice. Empirical treatment usually involves combination therapy, selected on the basis of known local epidemiology (usually a beta-lactam plus an aminoglycoside or a fluoroquinolone). However, therapy should be simplified as soon as possible, based on susceptibility data and the patient's clinical evolution. Alternative drugs (e.g., colistin) have proven useful against multiresistant strains, but innovative therapeutic options for the future remain scarce, while attempts to develop vaccines have been unsuccessful to date. Among broad-spectrum antibiotics in development, ceftobiprole, sitafloxacin and doripenem show interesting in-vitro activity, although the first two molecules have been evaluated in clinics only against Gram-positive organisms. Doripenem has received a fast track designation from the US Food and Drug Administration for the treatment of nosocomial pneumonia. Pump inhibitors are undergoing phase I trials in cystic fibrosis patients. Therefore, selecting appropriate antibiotics and optimising their use on the basis of pharmacodynamic concepts currently remains the best way of coping with pseudomonal infections.
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Affiliation(s)
- N Mesaros
- Unité de Pharmacologie cellulaire and moléculaire, Université catholique de Louvain, Bruxelles, Belgium
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Juretschko S, Labombardi VJ, Lerner SA, Schreckenberger PC. Accuracies of beta-lactam susceptibility test results for Pseudomonas aeruginosa with four automated systems (BD Phoenix, MicroScan WalkAway, Vitek, and Vitek 2). J Clin Microbiol 2007; 45:1339-42. [PMID: 17229867 PMCID: PMC1865858 DOI: 10.1128/jcm.01716-06] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Contemporary clinical isolates and challenge strains of Pseudomonas aeruginosa were tested by four automated susceptibility testing systems (BD Phoenix, MicroScan WalkAway, Vitek, and Vitek 2; two laboratories with each) against six broad-spectrum beta-lactams, and the results were compared to reference broth microdilution (BMD) and to consensus results from three validated methods (BMD, Etest [AB Biodisk, Solna, Sweden], and disk diffusion). Unacceptable levels of error (minor, major, and very major) were detected, some with systematic biases toward false susceptibility (piperacillin-tazobactam and imipenem) and others toward false resistance (aztreonam, cefepime, and ceftazidime). We encourage corrective action by the system manufacturers to address test biases, and we suggest that clinical laboratories using automated systems should consider accurate alternative methods for routine use.
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Affiliation(s)
- Stefan Juretschko
- Arkansas Children's Hospital, 800 Marshall Street, Little Rock, AR 72202, USA.
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Govan JRW. Multidrug-resistant pulmonary infection in cystic fibrosis – what does ‘resistant’ mean? J Med Microbiol 2006; 55:1615-1617. [PMID: 17108262 DOI: 10.1099/jmm.0.46884-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- J R W Govan
- Centre for Infectious Diseases, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK
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