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Costa SP, Carvalho CM. Burden of bacterial bloodstream infections and recent advances for diagnosis. Pathog Dis 2022; 80:6631550. [PMID: 35790126 DOI: 10.1093/femspd/ftac027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 06/07/2022] [Accepted: 07/01/2022] [Indexed: 11/13/2022] Open
Abstract
Bloodstream infections (BSIs) and subsequent organ dysfunction (sepsis and septic shock) are conditions that rank among the top reasons for human mortality and have a great impact on healthcare systems. Their treatment mainly relies on the administration of broad-spectrum antimicrobials since the standard blood culture-based diagnostic methods remain time-consuming for the pathogen's identification. Consequently, the routine use of these antibiotics may lead to downstream antimicrobial resistance and failure in treatment outcomes. Recently, significant advances have been made in improving several methodologies for the identification of pathogens directly in whole blood especially regarding specificity and time to detection. Nevertheless, for the widespread implementation of these novel methods in healthcare facilities, further improvements are still needed concerning the sensitivity and cost-effectiveness to allow a faster and more appropriate antimicrobial therapy. This review is focused on the problem of BSIs and sepsis addressing several aspects like their origin, challenges, and causative agents. Also, it highlights current and emerging diagnostics technologies, discussing their strengths and weaknesses.
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Affiliation(s)
- Susana P Costa
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal.,LABBELS - Associate Laboratory, Braga/Guimarães, Portugal.,International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal.,Instituto de Engenharia de Sistemas e Computadores - Microsistemas e Nanotecnologias (INESC MN) and IN - Institute of Nanoscience and Nanotechnology, Rua Alves Redol, 9 1000-029 Lisbon, Portugal
| | - Carla M Carvalho
- International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330, Braga, Portugal
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2
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Renaud C, Kollef MH. Classical and Molecular Techniques to Diagnose HAP/VAP. Semin Respir Crit Care Med 2022; 43:219-228. [PMID: 35042263 DOI: 10.1055/s-0041-1739359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Nosocomial pneumonia, including hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), are the most common nosocomial infections occurring in critically ill patients requiring intensive care. However, challenges exist in making a timely and accurate diagnosis of HAP and VAP. Under diagnosis of HAP and VAP can result in greater mortality risk, especially if accompanied by delays in the administration of appropriate antimicrobial treatment. Over diagnosis of HAP and VAP results in the unnecessary administration of broad spectrum antibiotics that can lead to further escalation of antibiotic resistance. Optimal diagnosis and management of HAP and VAP require a systematic approach that combines clinical and radiographic assessments along with proper microbiologic techniques. The use of more invasive sampling methods (bronchoalveolar lavage and protected specimen brush) may enhance specimen collection resulting in more specific diagnoses to limit unnecessary antibiotic exposure. Molecular techniques, currently in use and investigational technique, may improve the diagnosis of HAP and VAP by allowing more rapid identification of offending pathogens, if present, thus increasing both appropriate antibiotic treatment and avoiding unnecessary drug exposure.
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Affiliation(s)
- Cherie Renaud
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Marin H Kollef
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, Missouri
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3
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Holma T, Torvikoski J, Friberg N, Nevalainen A, Tarkka E, Antikainen J, Martelin JJ. Rapid molecular detection of pathogenic microorganisms and antimicrobial resistance markers in blood cultures: evaluation and utility of the next-generation FilmArray Blood Culture Identification 2 panel. Eur J Clin Microbiol Infect Dis 2021; 41:363-371. [PMID: 34350523 PMCID: PMC8831274 DOI: 10.1007/s10096-021-04314-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 07/09/2021] [Indexed: 11/30/2022]
Abstract
Rapid detection of pathogens causing bloodstream infections (BSI) directly from positive blood cultures is of highest importance in order to enable an adequate and timely antimicrobial therapy. In this study, the utility and performance of a recently launched next-generation fully automated test system, the Biofire FilmArray® Blood Culture Identification 2 (BCID2) panel, was evaluated using a set of 103 well-characterized microbial isolates including 29 antimicrobial resistance genes and 80 signal-positive and 23 signal-negative clinical blood culture samples. The results were compared to culture-based reference methods, MALDI-TOF, and/or 16S rDNA sequencing. Of the clinical blood culture samples, 68 were monomicrobial (85.0%) and 12 polymicrobial (15.0%). Six samples contained ESBL (blaCTX-M), two MRSA (mecA), and three MRSE (mecA) isolates. In overall, the FilmArray BCID2 panel detected well on-panel targets and resistance markers from mono- and polymicrobial samples. However, one Klebsiella aerogenes and one Bacteroides ovatus were undetected, and the assay falsely reported one Shigella flexneri as Escherichia coli. Hence, the sensitivity and specificity for detecting microbial species were 98.8% (95%CI, 95.8–99.9%) and 99.9% (95%CI, 99.8–99.9%), respectively. The sensitivity and specificity for detecting of resistance gene markers were 100%. The results were available within 70 min from signal-positive blood cultures with minimal hands-on time. In conclusion, the BCID2 test allows reliable and simplified detection of a vast variety of clinically relevant microbes causing BSI and the most common antimicrobial resistance markers present among these isolates.
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Affiliation(s)
- Tanja Holma
- HUS Diagnostic Center, HUSLAB, Department of Clinical Microbiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
| | - Jukka Torvikoski
- HUS Diagnostic Center, HUSLAB, Department of Clinical Microbiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Nathalie Friberg
- HUS Diagnostic Center, HUSLAB, Department of Clinical Microbiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Annika Nevalainen
- HUS Diagnostic Center, HUSLAB, Department of Clinical Microbiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Eveliina Tarkka
- HUS Diagnostic Center, HUSLAB, Department of Clinical Microbiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Jenni Antikainen
- HUS Diagnostic Center, HUSLAB, Department of Clinical Microbiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Jari J Martelin
- HUS Diagnostic Center, HUSLAB, Department of Clinical Microbiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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Adapa S, Naramala S, Boken D, Moreno A, Konala VM. Peritonitis from Anaerobic Gram-positive Cocci Likely Due to Translocation of Bacteria from Gut in a Patient Undergoing Peritoneal Dialysis. Cureus 2019; 11:e6060. [PMID: 31827990 PMCID: PMC6890156 DOI: 10.7759/cureus.6060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Peritonitis is a severe complication encountered in patients undergoing peritoneal dialysis, often causing high morbidity and mortality. High vigilance is required from healthcare providers involved in the management of these patients to prevent this complication. There has been recognition of peritonitis caused by unusual organisms because of improved microbiological detection techniques. Gram-positive organisms are the frequent cause of peritonitis compared to Gram-negative organisms. We report a rare case of peritonitis caused by Enterococcus avium. A 60-year-old male on peritoneal dialysis presented with palpitations, abdominal pain, diarrhea, and cloudy effluent. The peritoneal fluid analysis was consistent with peritonitis, and peritoneal fluid culture grew E. avium. The patient was treated with linezolid after failing to respond to vancomycin. The peritoneal dialysis catheter was removed, and the dialysis modality has been switched to hemodialysis because of refractory peritonitis.
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Affiliation(s)
- Sreedhar Adapa
- Internal Medicine/Nephrology, Kaweah Delta Medical Center, Visalia, USA
| | | | - Daniel Boken
- Internal Medicine/Infectious Disease, Kaweah Delta Medical Center, Visalia, USA
| | - Alan Moreno
- Internal Medicine/Nephrology, Kaweah Delta Medical Center, Visalia, USA
| | - Venu Madhav Konala
- Internal Medicine/Hematology and Oncology, Ashland Bellefonte Cancer Center, Ashland, USA
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5
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Abstract
The genus Enterococcus comprises a ubiquitous group of Gram-positive bacteria that are of great relevance to human health for their role as major causative agents of health care-associated infections. The enterococci are resilient and versatile species able to survive under harsh conditions, making them well adapted to the health care environment. Two species cause the majority of enterococcal infections: Enterococcus faecalis and Enterococcus faecium Both species demonstrate intrinsic resistance to common antibiotics, such as virtually all cephalosporins, aminoglycosides, clindamycin, and trimethoprim-sulfamethoxazole. Additionally, a remarkably plastic genome allows these two species to readily acquire resistance to further antibiotics, such as high-level aminoglycoside resistance, high-level ampicillin resistance, and vancomycin resistance, either through mutation or by horizontal transfer of genetic elements conferring resistance determinants.
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Affiliation(s)
- Mónica García-Solache
- Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Louis B Rice
- Department of Medicine, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
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Mach KE, Kaushik AM, Hsieh K, Wong PK, Wang TH, Liao JC. Optimizing peptide nucleic acid probes for hybridization-based detection and identification of bacterial pathogens. Analyst 2019; 144:1565-1574. [PMID: 30656297 PMCID: PMC7039532 DOI: 10.1039/c8an02194e] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Point-of-care (POC) diagnostics for infectious diseases have the potential to improve patient care and antibiotic stewardship. Nucleic acid hybridization is at the core of many amplification-free molecular diagnostics and detection probe configuration is key to diagnostic performance. Modified nucleic acids such as peptide nucleic acid (PNA) offer advantages compared to conventional DNA probes allowing for faster hybridization, better stability and minimal sample preparation for direct detection of pathogens. Probes with tethered fluorophore and quencher allow for solution-based assays and eliminate the need for washing steps thereby facilitating integration into microfluidic devices. Here, we compared the sensitivity and specificity of double stranded PNA probes (dsPNA) and PNA molecular beacons targeting E. coli and P. aeruginosa for direct detection of bacterial pathogens. In bulk fluid assays, the dsPNAs had an overall higher fluorescent signal and better sensitivity and specificity than the PNA beacons for pathogen detection. We further designed and tested an expanded panel of dsPNA probes for detection of a wide variety of pathogenic bacteria including probes for universal detection of eubacteria, Enterobacteriaceae family, and P. mirablis. To confirm that the advantage translated to other assay types we compared the PNA beacon and dsPNA in a prototype droplet microfluidic device. Beyond the bulk fluid assay and droplet devices, use of dsPNA probes may be advantageous in a wide variety of assays that employ homogenous nucleic acid hybridization.
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Affiliation(s)
- Kathleen E Mach
- Department of Urology, Stanford University School of Medicine, Stanford, CA, USA.
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Enroth H, Retz K, Andersson S, Andersson C, Svensson K, Ljungström L, Tilevik D, Pernestig AK. Evaluation of QuickFISH and maldi Sepsityper for identification of bacteria in bloodstream infection. Infect Dis (Lond) 2019; 51:249-258. [PMID: 30729840 DOI: 10.1080/23744235.2018.1554258] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Early detection of bacteria and their antibiotic susceptibility patterns are critical to guide therapeutic decision-making for optimal care of septic patients. The current gold standard, blood culturing followed by subculture on agar plates for subsequent identification, is too slow leading to excessive use of broad-spectrum antibiotic with harmful consequences for the patient and, in the long run, the public health. The aim of the present study was to assess the performance of two commercial assays, QuickFISH® (OpGen) and Maldi Sepsityper™ (Bruker Daltonics) for early and accurate identification of microorganisms directly from positive blood cultures. MATERIALS AND METHODS During two substudies of positive blood cultures, the two commercial assays were assessed against the routine method used at the clinical microbiology laboratory, Unilabs AB, at Skaraborg Hospital, Sweden. RESULTS The Maldi Sepsityper™ assay enabled earlier microorganism identification. Using the cut-off for definite species identification according to the reference method (>2.0), sufficiently accurate species identification was achieved, but only among Gram-negative bacteria. The QuickFISH® assay was time-saving and showed high concordance with the reference method, 94.8% (95% CI 88.4-98.3), when the causative agent was covered by the QuickFISH® assay. CONCLUSIONS The use of the commercial assays may shorten the time to identification of causative agents in bloodstream infections and can be a good complement to the current clinical routine diagnostics. Nevertheless, the performance of the commercial assays is considerably affected by the characteristics of the causative agents.
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Affiliation(s)
- Helena Enroth
- a Systems Biology Research Centre, School of Bioscience, University of Skövde , Skövde , Sweden.,b Department of Clinical Microbiology , Unilabs AB , Skövde , Sweden
| | - Karolina Retz
- a Systems Biology Research Centre, School of Bioscience, University of Skövde , Skövde , Sweden.,b Department of Clinical Microbiology , Unilabs AB , Skövde , Sweden
| | - Sofie Andersson
- b Department of Clinical Microbiology , Unilabs AB , Skövde , Sweden
| | - Carl Andersson
- a Systems Biology Research Centre, School of Bioscience, University of Skövde , Skövde , Sweden.,b Department of Clinical Microbiology , Unilabs AB , Skövde , Sweden
| | - Kristina Svensson
- b Department of Clinical Microbiology , Unilabs AB , Skövde , Sweden
| | - Lars Ljungström
- c Department of Infectious Diseases , Skaraborg Hospital , Skövde , Sweden
| | - Diana Tilevik
- a Systems Biology Research Centre, School of Bioscience, University of Skövde , Skövde , Sweden
| | - Anna-Karin Pernestig
- a Systems Biology Research Centre, School of Bioscience, University of Skövde , Skövde , Sweden
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Pilecky M, Schildberger A, Orth-Höller D, Weber V. Pathogen enrichment from human whole blood for the diagnosis of bloodstream infection: Prospects and limitations. Diagn Microbiol Infect Dis 2018; 94:7-14. [PMID: 30579657 DOI: 10.1016/j.diagmicrobio.2018.11.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/20/2018] [Accepted: 11/20/2018] [Indexed: 02/07/2023]
Abstract
Blood culture represents the current reference method for the detection of bacteria or fungi in the circulation. To accelerate pathogen identification, molecular diagnostic methods, mainly based on polymerase chain reaction (PCR), have been introduced to ensure early and targeted antibiotic treatment of patients suffering from bloodstream infection. Still, these approaches suffer from a lack of sensitivity and from inhibition of PCR in a number of clinical samples, leading to false negative results. To overcome these limitations, various approaches aiming at the enrichment of pathogens from larger blood volumes prior to the extraction of pathogen DNA, thereby also depleting factors interfering with PCR, have been developed. Here, we provide an overview of current systems for diagnosing bloodstream infection, with a focus on approaches for pre-analytical pathogen enrichment, and highlight emerging applications of pathogen depletion for therapeutic purposes as a potential adjunctive treatment of sepsis patients.
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Affiliation(s)
- Matthias Pilecky
- Center for Biomedical Technology, Department for Biomedical Research, Danube University Krems, Dr.-Karl-Dorrek-Strasse 30, 3500 Krems, Austria.
| | - Anita Schildberger
- Center for Biomedical Technology, Department for Biomedical Research, Danube University Krems, Dr.-Karl-Dorrek-Strasse 30, 3500 Krems, Austria.
| | - Dorothea Orth-Höller
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Schöpfstraße 41, A-6020 Innsbruck, Austria.
| | - Viktoria Weber
- Center for Biomedical Technology, Department for Biomedical Research, Danube University Krems, Dr.-Karl-Dorrek-Strasse 30, 3500 Krems, Austria; Christian Doppler Laboratory for Innovative Therapy Approaches in Sepsis, Department for Biomedical Research, Danube University Krems, Dr.-Karl-Dorrek-Strasse 30, 3500 Krems, Austria.
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9
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She RC, Bender JM. Advances in Rapid Molecular Blood Culture Diagnostics: Healthcare Impact, Laboratory Implications, and Multiplex Technologies. J Appl Lab Med 2018; 3:617-630. [PMID: 31639730 DOI: 10.1373/jalm.2018.027409] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 09/28/2018] [Indexed: 01/11/2023]
Abstract
BACKGROUND For far too long, the diagnosis of bloodstream infections has relied on time-consuming blood cultures coupled with traditional organism identification and susceptibility testing. Technologies to define the culprit in bloodstream infections have gained sophistication in recent years, notably by application of molecular methods. CONTENT In this review, we summarize the tests available to clinical laboratories for molecular rapid identification and resistance marker detection in blood culture bottles that have flagged positive. We explore the cost-benefit ratio of such assays, covering aspects that include performance characteristics, effect on patient care, and relevance to antibiotic stewardship initiatives. SUMMARY Rapid blood culture diagnostics represent an advance in the care of patients with bloodstream infections, particularly those infected with resistant organisms. These diagnostics are relatively easy to implement and appear to have a positive cost-benefit balance, particularly when fully incorporated into a hospital's antimicrobial stewardship program.
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Affiliation(s)
- Rosemary C She
- Department of Pathology, Keck School of Medicine of the University of Southern California, Los Angeles, CA;
| | - Jeffrey M Bender
- Division of Infectious Diseases of the Department of Pediatrics, Keck School of Medicine of the University of Southern California, Los Angeles, CA
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10
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Poole S, Kidd SP, Saeed K. A review of novel technologies and techniques associated with identification of bloodstream infection etiologies and rapid antimicrobial genotypic and quantitative phenotypic determination. Expert Rev Mol Diagn 2018; 18:543-555. [PMID: 29790810 DOI: 10.1080/14737159.2018.1480369] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
INTRODUCTION The antimicrobial aspect of management of patients with blood stream infections (BSI) and sepsis is time critical. In an era of increasing antimicrobial resistance, rapid detection and identification of bacteria with antimicrobial susceptibility is crucial to direct therapy early in the course of illness. Molecular techniques offer a potential solution to this. Areas covered: In the present review the authors have discussed a number of novel solutions utilizing a variety of molecular techniques for pathogen detection, identification and antimicrobial susceptibility. The review is not designed to be an exhaustive literature review covering all diagnostic solutions ever developed, instead the authors have focused on what they have had experience using, evaluating or currently view as new and exciting with potential to revolutionize BSI diagnosis. The authors searched PubMed (Medline) and Google Scholar with terms: BSI, Bacteraemia, Candidaemia, Diagnostics, AST, Rapid, AMR, Novel and Blood Culture. The authors attended recent clinical microbiology technology congresses. Expert commentary: There are multiple exciting novel technologies at differing stages of development with potential to revolutionize diagnosis of BSI. More work is needed as well as a standardized assessment of different platforms in order to better understand the clinical and financial impacts these will have in clinical microbiology laboratories.
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Affiliation(s)
- Stephen Poole
- a Hampshire Hospitals NHS Foundation Trust , Department of Microbiology , Basingstoke and Winchester , UK
| | - Stephen P Kidd
- a Hampshire Hospitals NHS Foundation Trust , Department of Microbiology , Basingstoke and Winchester , UK
| | - Kordo Saeed
- a Hampshire Hospitals NHS Foundation Trust , Department of Microbiology , Basingstoke and Winchester , UK.,b University of Southampton , School of medicine , Southampton , UK
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New Technologies for the Diagnosis of Infection. DIAGNOSTIC PATHOLOGY OF INFECTIOUS DISEASE 2018. [PMCID: PMC7152403 DOI: 10.1016/b978-0-323-44585-6.00006-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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12
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Davenport M, Mach KE, Shortliffe LMD, Banaei N, Wang TH, Liao JC. New and developing diagnostic technologies for urinary tract infections. Nat Rev Urol 2017; 14:296-310. [PMID: 28248946 PMCID: PMC5473291 DOI: 10.1038/nrurol.2017.20] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Timely and accurate identification and determination of the antimicrobial susceptibility of uropathogens is central to the management of UTIs. Urine dipsticks are fast and amenable to point-of-care testing, but do not have adequate diagnostic accuracy or provide microbiological diagnosis. Urine culture with antimicrobial susceptibility testing takes 2-3 days and requires a clinical laboratory. The common use of empirical antibiotics has contributed to the rise of multidrug-resistant organisms, reducing treatment options and increasing costs. In addition to improved antimicrobial stewardship and the development of new antimicrobials, novel diagnostics are needed for timely microbial identification and determination of antimicrobial susceptibilities. New diagnostic platforms, including nucleic acid tests and mass spectrometry, have been approved for clinical use and have improved the speed and accuracy of pathogen identification from primary cultures. Optimization for direct urine testing would reduce the time to diagnosis, yet these technologies do not provide comprehensive information on antimicrobial susceptibility. Emerging technologies including biosensors, microfluidics, and other integrated platforms could improve UTI diagnosis via direct pathogen detection from urine samples, rapid antimicrobial susceptibility testing, and point-of-care testing. Successful development and implementation of these technologies has the potential to usher in an era of precision medicine to improve patient care and public health.
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Affiliation(s)
- Michael Davenport
- Department of Urology, Stanford University School of Medicine, 300 Pasteur Drive S-287, Stanford, California 94305 USA
| | - Kathleen E Mach
- Department of Urology, Stanford University School of Medicine, 300 Pasteur Drive S-287, Stanford, California 94305 USA
| | - Linda M Dairiki Shortliffe
- Department of Urology, Stanford University School of Medicine, 300 Pasteur Drive S-287, Stanford, California 94305 USA
| | - Niaz Banaei
- Department of Pathology, Stanford University School of Medicine, 3375 Hillview Avenue, Palo Alto, California 94304 USA
| | - Tza-Huei Wang
- Departments of Mechanical and Biomedical Engineering, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, USA
| | - Joseph C Liao
- Department of Urology, Stanford University School of Medicine, 300 Pasteur Drive S-287, Stanford, California 94305 USA
- Veterans Affairs Palo Alto Health Care System, 3801 Miranda Avenue, Palo Alto, California 94304 USA
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Sharma C, Awasthi SK. Versatility of peptide nucleic acids (PNAs): role in chemical biology, drug discovery, and origins of life. Chem Biol Drug Des 2016; 89:16-37. [PMID: 27490868 DOI: 10.1111/cbdd.12833] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 06/03/2016] [Accepted: 07/28/2016] [Indexed: 12/16/2022]
Abstract
This review briefly discussed nomenclature, synthesis, chemistry, and biophysical properties of a plethora of PNA derivatives reported since the discovery of aegPNA. Different synthetic methods and structural analogs of PNA synthesized till date were also discussed. An insight was gained into various chemical, physical, and biological properties of PNA which make it preferable over all other classes of modified nucleic acid analogs. Thereafter, various approaches with special attention to the practical constraints, characteristics, and inherent drawbacks leading to the delay in the development of PNA as gene therapeutic drug were outlined. An explicit account of the successful application of PNA in different areas of research such as antisense and antigene strategies, diagnostics, molecular probes, and so forth was described along with the current status of PNA as gene therapeutic drug. Further, the plausibility of the existence of PNA and its role in primordial chemistry, that is, origin of life was explored in an endeavor to comprehend the mystery and open up its deepest secrets ever engaging and challenging the human intellect. We finally concluded it with a discussion on the future prospects of PNA technology in the field of therapeutics, diagnostics, and origin of life.
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Affiliation(s)
- Chiranjeev Sharma
- Chemical Biology Laboratory, Department of Chemistry, University of Delhi, Delhi, India
| | - Satish Kumar Awasthi
- Chemical Biology Laboratory, Department of Chemistry, University of Delhi, Delhi, India
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14
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Molecular and Mass Spectrometry Detection and Identification of Causative Agents of Bloodstream Infections. Mol Microbiol 2016. [DOI: 10.1128/9781555819071.ch26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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15
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Dubourg G, Raoult D. Emerging methodologies for pathogen identification in positive blood culture testing. Expert Rev Mol Diagn 2015; 16:97-111. [PMID: 26559655 DOI: 10.1586/14737159.2016.1112274] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Bloodstream infections (BSIs) represent a major cause of death in developed countries and are associated with long-term loss of functions. Blood culture remains the gold standard for BSI diagnosis, as it is easy to perform and displays a good analytical sensitivity. However, its major drawback remains the long turnaround time, which can result in inappropriate therapy, fall of survival rate, emergence of antibiotic resistance and increase of medical costs. Over the last 10 years, molecular tools have been the alternative to blood cultures, allowing early identification of pathogens involved in sepsis, as well detection of critical antibiotic resistance genes. Besides, the advent of MALDI-TOF revolutionized practice in routine microbiology significantly reduced the time to result. Reviewed here are recent improvements in early BSI diagnosis and these authors' view for the future is presented, including innovative high-throughput technologies.
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Affiliation(s)
- Grégory Dubourg
- a Pôle des Maladies Infectieuses et Tropicales Clinique et Biologique, Fédération de Bactériologie-Hygiène-Virologie, University, Hospital Centre Timone, Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, Assistance Publique - Hôpitaux de Marseille , Marseille , France.,b Université Aix-Marseille, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE) UM 63 CNRS 7278 IRD 198 INSERM U1095, Facultés de Médecine et de Pharmacie , Marseille , France
| | - Didier Raoult
- a Pôle des Maladies Infectieuses et Tropicales Clinique et Biologique, Fédération de Bactériologie-Hygiène-Virologie, University, Hospital Centre Timone, Institut Hospitalo-Universitaire (IHU) Méditerranée Infection, Assistance Publique - Hôpitaux de Marseille , Marseille , France.,b Université Aix-Marseille, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE) UM 63 CNRS 7278 IRD 198 INSERM U1095, Facultés de Médecine et de Pharmacie , Marseille , France
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Blood culture-based diagnosis of bacteraemia: state of the art. Clin Microbiol Infect 2015; 21:313-22. [PMID: 25753137 DOI: 10.1016/j.cmi.2015.01.003] [Citation(s) in RCA: 254] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 01/01/2015] [Accepted: 01/06/2015] [Indexed: 01/23/2023]
Abstract
Blood culture remains the best approach to identify the incriminating microorganisms when a bloodstream infection is suspected, and to guarantee that the antimicrobial treatment is adequate. Major improvements have been made in the last years to increase the sensitivity and specificity and to reduce the time to identification of microorganisms recovered from blood cultures. Among other factors, the introduction in clinical microbiology laboratories of the matrix-assisted laser desorption ionization time-of-flight mass spectrometry technology revolutionized the identification of microorganisms whereas the introduction of nucleic-acid-based methods, such as DNA hybridization or rapid PCR-based test, significantly reduce the time to results. Together with traditional antimicrobial susceptibility testing, new rapid methods for the detection of resistance mechanisms respond to major epidemiological concerns such as methicillin-resistant Staphylococcus aureus, extended-spectrum β-lactamase or carbapenemases. This review presents and discusses the recent developments in microbial diagnosis of bloodstream infections based on blood cultures.
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17
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Artificial Nucleic Acid Probes and Their Applications in Clinical Microbiology. METHODS IN MICROBIOLOGY 2015. [DOI: 10.1016/bs.mim.2015.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Evaluation of real-time PCR and pyrosequencing for screening incubating blood culture bottles from adults with suspected bloodstream infection. Diagn Microbiol Infect Dis 2014; 81:158-62. [PMID: 25534615 DOI: 10.1016/j.diagmicrobio.2014.11.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Revised: 11/05/2014] [Accepted: 11/24/2014] [Indexed: 11/24/2022]
Abstract
Several molecular platforms can identify bacteria associated with bloodstream infections but require positive culture bottles as starting material. Here, we describe results of screening 1140 blood cultures at 8h postinoculation, from 918 eligible adults being evaluated for bloodstream infection. DNA was extracted and analyzed by 16S and/or 23S rRNA real-time PCR/pyrosequencing. Compared to culture, PCR/pyrosequencing displayed 90.9% sensitivity, 99.6% specificity, 95.7% positive predictive value, and 99.1% negative predictive value. Overall concordance rate was 98.9% (1127/1140). In 4 cases with molecular-positive/culture-negative results, medical chart reviews provided evidence of identical bacteria from subsequent blood or concomitant urine/sputum cultures. Nine culture-positive/molecular-negative cases were associated with either polymicrobial growth, grew only in the anaerobic bottle of the clinical pair, and/or were detected by PCR/pyrosequencing after 8h. In summary, this approach accurately detected and identified bacteria in ~91% of culture-confirmed cases significantly sooner than the phenotypic identification was available, having the potential to improve antibiotic stewardship.
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Evaluation of three rapid diagnostic methods for direct identification of microorganisms in positive blood cultures. J Clin Microbiol 2014; 52:2521-9. [PMID: 24808235 DOI: 10.1128/jcm.00529-14] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The identification of organisms from positive blood cultures generally takes several days. However, recently developed rapid diagnostic methods offer the potential for organism identification within only a few hours of blood culture positivity. In this study, we evaluated the performance of three commercial methods to rapidly identify organisms directly from positive blood cultures: QuickFISH (AdvanDx, Wolburn, MA), Verigene Gram-Positive Blood Culture (BC-GP; Nanosphere, Northbrook, IL), and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) with Sepsityper processing (Bruker Daltonics, Billerica, MA). A total of 159 blood cultures (VersaTREK Trek Diagnostic Systems, Cleveland, OH) positive for Gram-positive and Gram-negative bacteria as well as yeast were analyzed with QuickFISH and MALDI-TOF MS. In all, 102 blood cultures were analyzed using the BC-GP assay. For monomicrobial cultures, we observed 98.0% concordance with routine methods for both QuickFISH (143/146) and the BC-GP assay (93/95). MALDI-TOF MS demonstrated 80.1% (117/146) and 87.7% (128/146) concordance with routine methods to the genus and species levels, respectively. None of the methods tested were capable of consistently identifying polymicrobial cultures in their entirety or reliably differentiating Streptococcus pneumoniae from viridans streptococci. Nevertheless, the methods evaluated in this study are convenient and accurate for the most commonly encountered pathogens and have the potential to dramatically reduce turnaround time for the provision of results to the treating physician.
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