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Langner KFA, Yang WJ. Clinical performance of the IMMY cryptococcal antigen lateral flow assay in dogs and cats. Vet Med (Auckl) 2022; 36:1966-1973. [PMID: 36254569 DOI: 10.1111/jvim.16555] [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: 03/06/2022] [Accepted: 09/16/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND Cryptococcal lateral flow antigen assays (CLFAs) have been assessed in comparison to the latex cryptococcal antigen agglutination test but their clinical performance is unknown. OBJECTIVE Determine clinical performance of IMMY CLFA (Immuno-Mycologics Inc, Oklahoma) using patients with and without cryptococcosis as the reference standard. ANIMALS One-hundred ninety-seven serum samples from client-owned dogs and cats. METHODS Review of medical records of a referral population of dogs and cats that had CLFA performed between 2012 and 2020. Animals were classified as cryptococcosis positive (Cr+) or negative (Cr-) based on clinical information. Clinical diagnosis was used to calculate positive and negative percent agreement of the CLFA. RESULTS Twelve specimens (4 canine, 8 feline) were obtained from Cr+ animals and had positive CLFA results. One-hundred eighty-five specimens (139 canine, 46 feline) were collected from Cr- animals. Negative CLFA results were recorded in 129 canine and 44 feline Cr- samples. Positive CLFA results were noted for 10 canine and 2 feline Cr- samples. Positive percent agreement of CLFA was 100% (confidence interval [CI], 39.8%-100% dogs; 63.1%-100% cats). Negative percent agreements were 92.8% (CI, 87.2%-96.5%) for dogs and 95.7% (CI, 85.2%-99.5%) for cats. CONCLUSIONS AND CLINICAL IMPORTANCE A negative IMMY CLFA result enables reliable exclusion of cryptococcal infection in dogs and cats. By contrast, a positive result must be interpreted cautiously and further testing should be performed to verify a diagnosis of cryptococcosis.
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Affiliation(s)
- Kathrin F A Langner
- Western Australian Veterinary Emergency and Specialty, Success, Western Australia, Australia
| | - Wen-Jie Yang
- Veterinary Specialists Aotearoa, Auckland, New Zealand
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Liu Y, Kang M, Wu SY, Wu LJ, He L, Xiao YL, Zhang WL, Liao QF, Deng J, Chen ZX, Ma Y. Evaluation of a Cryptococcus Capsular Polysaccharide Detection FungiXpert LFA (Lateral Flow Assay) for the Rapid Diagnosis of Cryptococcosis. Med Mycol 2022; 60:6562084. [PMID: 35362524 DOI: 10.1093/mmy/myac020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 02/22/2022] [Indexed: 02/05/2023] Open
Abstract
Cryptococcus is an opportunistic pathogenic fungus and is the major cause of fungal meningitis. The cryptococcal antigen (CrAg) lateral flow assay (LFA) is an immunochromatographic test system that has simplified diagnosis as a point-of-care test. In this study, we evaluated the diagnostic performance of Cryptococcal capsular polysaccharide detection FungiXpert (Genobio Pharmaceutical, Tianjin, China) using serum and cerebrospinal fluid (CSF) samples for the diagnosis of cryptococcosis and investigated the cross-reaction of the assays to pathogenic fungi and bacterium by comparing it to the U.S. Food and Drug Administration (US FDA)-approved IMMY CrAg LFA. Eighty CSF and 119 serum/plasma samples from 158 patients were retrospectively collected to test for qualitative or semi-quantitative detection of CrAg. Cross-reaction of the assays was tested using 28 fungi and 1 bacterium. Compared to IMMY CrAg LFA, the FungiXpert LFA demonstrated 99.1% sensitivity and 98.9% specificity in the qualitative test. In the 96 semi-quantitative CrAg assay results, 39 (40.6%) test titers of FungiXpert LFA were 1-2 dilutions higher than those of IMMY CrAg LFA. The Intraclass Correlation Coefficient of the Semi-quantitative results of CrAg titer tests via the two assays was 0.976. Similar to IMMY CrAg LFA, FungiXpert LFA showed cross-reactivity with Trichosporon asahii. Compared with the IMMY CrAg LFA, the FungiXpert LFA showed an equal, yet, excellent performance. However, it is important to note that these two assays have potential cross-reactivity to T. asahii when diagnosing patients. FungiXpert LFA is a rapid screening method for the effective and practical diagnosis and treatment of cryptococcosis.
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Affiliation(s)
- Ya Liu
- Division of Clinical Microbiology, Department of Laboratory Medicine, West China Hospital Sichuan University, Chengdu, China
| | - Mei Kang
- Division of Clinical Microbiology, Department of Laboratory Medicine, West China Hospital Sichuan University, Chengdu, China
| | - Si-Ying Wu
- Division of Clinical Microbiology, Department of Laboratory Medicine, West China Hospital Sichuan University, Chengdu, China
| | - Li-Juan Wu
- Department of Laboratory Medicine, Guigang City People's Hospital, Guigang, China
| | - Lan He
- Department of Laboratory Medicine, The Sixth People's Hospital of Chengdu, Chengdu, China
| | - Yu-Ling Xiao
- Division of Clinical Microbiology, Department of Laboratory Medicine, West China Hospital Sichuan University, Chengdu, China
| | - Wei-Li Zhang
- Division of Clinical Microbiology, Department of Laboratory Medicine, West China Hospital Sichuan University, Chengdu, China
| | - Quan-Feng Liao
- Division of Clinical Microbiology, Department of Laboratory Medicine, West China Hospital Sichuan University, Chengdu, China
| | - Jin Deng
- Division of Clinical Microbiology, Department of Laboratory Medicine, West China Hospital Sichuan University, Chengdu, China
| | - Zhi-Xing Chen
- Division of Clinical Microbiology, Department of Laboratory Medicine, West China Hospital Sichuan University, Chengdu, China
| | - Ying Ma
- Division of Clinical Microbiology, Department of Laboratory Medicine, West China Hospital Sichuan University, Chengdu, China
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Production of Secreted Carbohydrates that Present Immunologic Similarities with the Cryptococcus Glucuronoxylomannan by Members of the Trichosporonaceae Family: A Comparative Study Among Species of Clinical Interest. Mycopathologia 2021; 186:377-385. [PMID: 33956292 DOI: 10.1007/s11046-021-00558-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 04/22/2021] [Indexed: 10/20/2022]
Abstract
Glucuronoxylomannan (GXM) participates in several immunoregulatory mechanisms, which makes it an important Cryptococcus virulence factor that is essential for the disease. Trichosporon asahii and Trichosporon mucoides share with Cryptococcus species the ability to produce GXM. To check whether other opportunistic species in the Trichosporonaceae family produce GXM-like polysaccharides, extracts from 28 strains were produced from solid cultures and their carbohydrate content evaluated by the sulfuric acid / phenol method. Moreover, extracts were assessed for cryptococcal GXM cross-reactivity through latex agglutination and lateral flow assay methods. Cryptococcus neoformans and Saccharomyces cerevisiae were used as positive and negative controls, respectively. In addition to T. asahii, the species Trichosporon inkin, Apiotrichum montevideense, Trichosporon japonicum, Trichosporon faecale, Trichosporon ovoides, Cutaneotrichosporon debeurmannianum, and Cutaneotrichosporon arboriformis are also producers of a polysaccharide immunologically similar to the GXM produced by human pathogenic Cryptococcus species. The carbohydrate concentration of the extracts presented a positive correlation with the GXM contents determined by titration of both methodologies. These results add several species to the list of fungal pathogens that produce glycans of the GXM type and bring information about the origin of potential false-positive results on immunological tests for diagnosis of cryptococcosis based on GXM detection.
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Eshwara VK, Garg R, Chandrashekhar GS, Shaw T, Mukhopadhyay C. Fatal Cryptococcus gattii meningitis with negative cryptococcal antigen test in a HIV-non-infected patient. Indian J Med Microbiol 2019; 36:439-440. [PMID: 30429403 DOI: 10.4103/ijmm.ijmm_18_164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Cryptococcus gattii predominantly causes central nervous system and pulmonary infection in both immunocompromised and immunocompetent patients with substantial morbidity. We report a case of rapidly fatal meningitis by C. gattii in an HIV-non-infected man with CD4 lymphopenia who tested negative for cryptococcal antigen. This case may serve as an alert to its wider occurrence and less explored risk factors.
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Affiliation(s)
- Vandana Kalwaje Eshwara
- Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Rahul Garg
- Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | | | - Tushar Shaw
- Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Chiranjay Mukhopadhyay
- Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India
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5
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Abstract
The molecular composition of the cell wall is critical for the biology and ecology of each fungal species. Fungal walls are composed of matrix components that are embedded and linked to scaffolds of fibrous load-bearing polysaccharides. Most of the major cell wall components of fungal pathogens are not represented in humans, other mammals, or plants, and therefore the immune systems of animals and plants have evolved to recognize many of the conserved elements of fungal walls. For similar reasons the enzymes that assemble fungal cell wall components are excellent targets for antifungal chemotherapies and fungicides. However, for fungal pathogens, the cell wall is often disguised since key signature molecules for immune recognition are sometimes masked by immunologically inert molecules. Cell wall damage leads to the activation of sophisticated fail-safe mechanisms that shore up and repair walls to avoid catastrophic breaching of the integrity of the surface. The frontiers of research on fungal cell walls are moving from a descriptive phase defining the underlying genes and component parts of fungal walls to more dynamic analyses of how the various components are assembled, cross-linked, and modified in response to environmental signals. This review therefore discusses recent advances in research investigating the composition, synthesis, and regulation of cell walls and how the cell wall is targeted by immune recognition systems and the design of antifungal diagnostics and therapeutics.
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6
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Abstract
The molecular composition of the cell wall is critical for the biology and ecology of each fungal species. Fungal walls are composed of matrix components that are embedded and linked to scaffolds of fibrous load-bearing polysaccharides. Most of the major cell wall components of fungal pathogens are not represented in humans, other mammals, or plants, and therefore the immune systems of animals and plants have evolved to recognize many of the conserved elements of fungal walls. For similar reasons the enzymes that assemble fungal cell wall components are excellent targets for antifungal chemotherapies and fungicides. However, for fungal pathogens, the cell wall is often disguised since key signature molecules for immune recognition are sometimes masked by immunologically inert molecules. Cell wall damage leads to the activation of sophisticated fail-safe mechanisms that shore up and repair walls to avoid catastrophic breaching of the integrity of the surface. The frontiers of research on fungal cell walls are moving from a descriptive phase defining the underlying genes and component parts of fungal walls to more dynamic analyses of how the various components are assembled, cross-linked, and modified in response to environmental signals. This review therefore discusses recent advances in research investigating the composition, synthesis, and regulation of cell walls and how the cell wall is targeted by immune recognition systems and the design of antifungal diagnostics and therapeutics.
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Affiliation(s)
- Neil A R Gow
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB252ZD, United Kingdom
| | | | - Carol A Munro
- Aberdeen Fungal Group, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB252ZD, United Kingdom
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7
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Equine Pulmonary Cryptococcosis: A Comparative Literature Review and Evaluation of Fluconazole Monotherapy. Mycopathologia 2016; 182:413-423. [PMID: 27655152 DOI: 10.1007/s11046-016-0065-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 09/05/2016] [Indexed: 12/18/2022]
Abstract
Cryptococcus is the most common fungal respiratory pathogen in Australian horses, manifesting primarily as pulmonary granulomas. Disease severity at presentation is dependent on the athletic use of the horse. The diagnosis and estimation of disease severity are centred around clinical findings, cytological evaluation of respiratory tract secretions, diagnostic imaging, and antigen titre testing. Both the lateral flow assay and the latex cryptococcal antigen titre are used, and important similarities and differences between species are discussed. Cryptococcus gattii occurs with greater frequency than Cryptococcus neoformans in equine pulmonic cryptococcosis and can be successfully treated with enteral fluconazole monotherapy, with disease severity determining treatment length.
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8
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Chen M, Zhou J, Li J, Li M, Sun J, Fang WJ, Al-Hatmi AMS, Xu J, Boekhout T, Liao WQ, Pan WH. Evaluation of five conventional and molecular approaches for diagnosis of cryptococcal meningitis in non-HIV-infected patients. Mycoses 2016; 59:494-502. [PMID: 27061343 DOI: 10.1111/myc.12497] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 01/19/2016] [Accepted: 02/22/2016] [Indexed: 11/29/2022]
Abstract
Cryptococcal meningitis (CM) is a life-threatening mycosis primarily occurring in HIV-infected individuals. Recently, non-HIV-infected hosts were increasingly reported to form a considerable proportion. However, the majority of the reported studies on the diagnosis of CM patients were performed on HIV-infected patients. For evaluation of various diagnostic approaches for CM in non-HIV-infected patients, a range of conventional and molecular assays used for diagnosis of CM were verified on 85 clinical CSFs from non-HIV-infected CM patients, including India ink staining, culture, a newly developed loop-mediated isothermal amplification (LAMP), the lateral flow assay (LFA) of cryptococcal antigen detection and a qPCR assay. The LFA had the highest positive detection rate (97.6%; 95% CI, 91.8-99.7%) in non-HIV-infected CM patients, followed by the LAMP (87.1%; 95% CI, 78.0-93.4%), the qPCR (80.0%; 95% CI, 69.9-87.9%), India ink staining (70.6%; 95% CI, 59.7-80.0%) and culture (35.3%; 95% CI, 25.2-46.4%). All culture positive specimens were correctly identified by the LFA.
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Affiliation(s)
- Min Chen
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China.,CBS-KNAW Fungal Biodiversity Centre, Utrecht, the Netherlands
| | - Jie Zhou
- Department of Dermatology, Shanghai Seventh People's Hospital, Shanghai, China
| | - Juan Li
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Meng Li
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Jun Sun
- Department of Pharmacy, General Hospital of Jinan Military Command, Jinan, China
| | - Wen J Fang
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Abdullah M S Al-Hatmi
- CBS-KNAW Fungal Biodiversity Centre, Utrecht, the Netherlands.,Directorate General of Health Services, Ministry of Health, Ibri Hospital, Ibri, Oman
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, Canada
| | - Teun Boekhout
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China.,CBS-KNAW Fungal Biodiversity Centre, Utrecht, the Netherlands
| | - Wan Q Liao
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Wei H Pan
- Department of Dermatology, Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China
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9
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Abstract
Diagnostic tools for invasive fungal infections have continuously improved within the last decades. Nowadays, cultural methods, antigen testing, and molecular tests, such as polymerase chain reaction, are widely used. These methods, however, are accompanied with different limitations as various availability, various turnaround time or high costs. A new generation of point-of-care test has shown promising results in various studies and may overcome some of these limitations. We therefore reviewed the literature for the most promising new point-of-care tests for invasive aspergillosis (Aspergillus-specific lateral-flow device test, Aspergillus proximity ligation antigen assay), cryptococcosis (cryptococcal lateral-flow assay), and for histoplasmosis (loop-mediated isothermal amplification assay).
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10
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Arıkan Akdağlı S, Azap A, Başaran Demirkazık F, Ener B, Aşcıoğlu Hayran S, Özdemir Kumbasar Ö, Metan G, Odabaşı Z, Uzun Ö, Akan H. Diagnosis of Invasive Fungal Diseases in Hematological Malignancies: A Critical Review of Evidence and Turkish Expert Opinion (TEO-2). Turk J Haematol 2015; 31:342-56. [PMID: 25541650 PMCID: PMC4454048 DOI: 10.4274/tjh.2014.0218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
One of the most problematic issues in hematological malignancies is the diagnosis of invasive fungal diseases. Especially, the difficulty of mycological diagnosis and the necessity of immediate intervention in molds have led to the adoption of “surrogate markers” that do not verify but rather strongly suggest fungal infection. The markers commonly used are galactomannan (GM), beta-glucan, and imaging methods. Although there are numerous studies on these diagnostic approaches, none of these markers serve as a support for the clinician, as is the case in human immunodeficiency virus (HIV) or cytomegalovirus (CMV) infections. This paper has been prepared to explain the diagnostic tests. As molecular tests have not been standardized and are not used routinely in the clinics, they will not be mentioned here.
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11
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Tintelnot K, Hagen F, Han CO, Seibold M, Rickerts V, Boekhout T. Pitfalls in Serological Diagnosis of Cryptococcus gattii Infections. Med Mycol 2015; 53:874-9. [PMID: 26337090 DOI: 10.1093/mmy/myv061] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 06/09/2015] [Indexed: 02/07/2023] Open
Abstract
The detection of cryptococcal antigen by latex agglutination tests (LATs), enzyme-linked immunoassays (ELISA), or lateral flow assay (LFA) is an important tool for diagnosis of a Cryptococcus infection. Cerebrospinal fluid and/or serum samples of 10 patients with cryptococcosis due to Cryptococcus gattii or a hybrid of Cryptococcus neoformans and C. gattii were examined by three LATs (the IMMY Latex-Crypto(®) test, the Pastorex(TM) Crypto Plus, and the Remel Cryptococcus Antigen Test Kit) and the LFA made by Immuno-Mycologics. LATs based on monoclonal antibodies (mAbs) like the Pastorex(TM) Crypto Plus or the Remel Cryptococcus Antigen Test Kit turned out to have an insufficient sensitivity to detect four out of 10 C. gattii infections, including one infection by a hybrid between C. gattii and C. neoformans. Reflecting the ongoing expansion of C. gattii in geographical zones outside of tropical and subtropical areas like Mediterranean countries, Vancouver Island (British Columbia, Canada) and the Pacific Northwest region (USA), these findings are alarming because of the risk of delayed diagnosis of infections caused by C. gattii. Therefore, the preliminary serological screening for cryptococcal antigen in the case of a suspected Cryptococcus infection should be performed by using an assay with a broad range specificity and sensitivity for C. neoformans and C. gattii, including their hybrids.
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Affiliation(s)
| | - Ferry Hagen
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands
| | - Chang Ok Han
- Division of Mycology, Robert Koch Institute, Berlin, Germany
| | - Michael Seibold
- Division of Mycology, Robert Koch Institute, Berlin, Germany
| | - Volker Rickerts
- Division of Mycology, Robert Koch Institute, Berlin, Germany
| | - Teun Boekhout
- CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands
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12
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British Society for Medical Mycology best practice recommendations for the diagnosis of serious fungal diseases. THE LANCET. INFECTIOUS DISEASES 2015; 15:461-74. [PMID: 25771341 DOI: 10.1016/s1473-3099(15)70006-x] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Invasive fungal diseases are an important cause of morbidity and mortality in a wide range of patients, and early diagnosis and management are a challenge. We therefore did a review of the scientific literature to generate a series of key recommendations for the appropriate use of microbiological, histological, and radiological diagnostic methods for diagnosis of invasive fungal diseases. The recommendations emphasise the role of microscopy in rapid diagnosis and identification of clinically significant isolates to species level, and the need for susceptibility testing of all Aspergillus spp, if treatment is to be given. In this Review, we provide information to improve understanding of the importance of antigen detection for cryptococcal disease and invasive aspergillosis, the use of molecular (PCR) diagnostics for aspergillosis, and the crucial role of antibody detection for chronic and allergic aspergillosis. Furthermore, we consider the importance of histopathology reporting with a panel of special stains, and emphasise the need for urgent (<48 hours) and optimised imaging for patients with suspected invasive fungal infection. All 43 recommendations are auditable and should be used to ensure best diagnostic practice and improved outcomes for patients.
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Tang MW, Clemons KV, Katzenstein DA, Stevens DA. The cryptococcal antigen lateral flow assay: A point-of-care diagnostic at an opportune time. Crit Rev Microbiol 2015; 42:634-42. [PMID: 25612826 DOI: 10.3109/1040841x.2014.982509] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Cryptococcal meningitis is a devastating HIV-related opportunistic infection, affecting nearly 1 million individuals and causing over 500 000 deaths each year. The burden of disease is greatest in sub-Saharan Africa and Southeast Asia, where cryptococcal disease is the most common cause of meningitis. Rapid, accurate and affordable diagnosis of cryptococcal disease has been lacking in many of the most heavily affected areas. Here, we review a point-of-care assay for cryptococcal disease, the dipstick-formatted cryptococcal antigen lateral flow assay (LFA) (IMMY, Norman, OK). In comparison to culture, the assay is 99.5% sensitive and 98% specific. In comparison to other commercially available tests for cryptococcal antigen, the LFA has equal or superior sensitivity and specificity in CSF, plasma and serum samples. We discuss potential applications for the use of the assay in resource-limited settings, including what is likely to be an important role of the LFA in screening for early cryptococcal infection before clinical disease and in evaluating pre-emptive treatment.
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Affiliation(s)
- Michele W Tang
- a The Division of Infectious Diseases and Geographic Medicine , Stanford University , Stanford , CA , USA and.,b California Institute for Medical Research , San Jose , CA , USA
| | - Karl V Clemons
- a The Division of Infectious Diseases and Geographic Medicine , Stanford University , Stanford , CA , USA and.,b California Institute for Medical Research , San Jose , CA , USA
| | - David A Katzenstein
- a The Division of Infectious Diseases and Geographic Medicine , Stanford University , Stanford , CA , USA and
| | - David A Stevens
- a The Division of Infectious Diseases and Geographic Medicine , Stanford University , Stanford , CA , USA and.,b California Institute for Medical Research , San Jose , CA , USA
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Navabi N, Montebatsi M, Scott M, Gluckman SJ, Reid MJA. Case report: false negative serum cryptococcal latex agglutination test in a patient with disseminated cryptococcal disease. J Int Assoc Provid AIDS Care 2014; 14:123-6. [PMID: 25331223 DOI: 10.1177/2325957414555233] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A case of false-negative serum latex agglutination cryptococcal antigen (CRAG) test in a 45-year-old HIV-positive male with Cryptococcus-positive culture is described. The patient was presented to a hospital in Botswana, with breathlessness and a diffuse papular rash. His CD4 count was 25 cells/μL. Despite the suspicion for disseminated cryptococcal disease, an initial serum CRAG latex test was negative. Results of subsequent Indian ink staining, culture of cerebrospinal fluid and skin scrapings, and serum lateral flow immunoassay (LFA) were all positive for Cryptococcus neoformans. There are several possible explanations for the false-negative CRAG latex test. Given the positive LFA result, we speculate that disease may have been caused by Cryptococcus gattii, which is estimated to be responsible for between 15% and 30% of all cryptococcal diseases in Botswana. Reduced sensitivity of CRAG latex assays for detecting C gattii may lead to underdiagnosis of cryptococcal infection.
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Affiliation(s)
| | | | | | | | - Michael J A Reid
- University of Pennsylvania, Pennsylvania, PA, USA Botswana UPenn Partnership, Gaborone, Botswana
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15
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Affiliation(s)
- M Backx
- Specialist Registrar in Infectious Diseases and Medical Microbiology
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16
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Lamoth F, Alexander BD. Nonmolecular methods for the diagnosis of respiratory fungal infections. Clin Lab Med 2014; 34:315-36. [PMID: 24856530 DOI: 10.1016/j.cll.2014.02.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Diagnosis of invasive fungal pneumonias by conventional culture methods is difficult to assess and often delayed. Nonmolecular fungal markers have emerged as an important adjunctive tool to support their diagnosis in combination with other clinical, radiologic, and microbiological criteria of invasive fungal diseases. Concerns about the sensitivity and specificity of some tests in different patient populations should lead to warnings about their widespread use. None can identify the emerging and particularly deadly fungal pathogens responsible for mucormycosis. The role of nonmolecular fungal markers should be better defined in combination with other microbiological and radiologic tools in preemptive antifungal strategies.
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Affiliation(s)
- Frédéric Lamoth
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Box 102359, Durham, NC 27710, USA; Clinical Microbiology Laboratory, Department of Pathology, Duke University Medical Center, 108 Carl building, Durham, NC 27710, USA; Infectious Diseases Service and Institute of Microbiology, Lausanne University Hospital, Rue du Bugnon 46, 1011 Lausanne, Switzerland.
| | - Barbara D Alexander
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Box 102359, Durham, NC 27710, USA; Clinical Microbiology Laboratory, Department of Pathology, Duke University Medical Center, 108 Carl building, Durham, NC 27710, USA.
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17
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Production of latex agglutination reagents for pneumococcal serotyping. BMC Res Notes 2013; 6:49. [PMID: 23379961 PMCID: PMC3570367 DOI: 10.1186/1756-0500-6-49] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 01/24/2013] [Indexed: 11/29/2022] Open
Abstract
Background The current ‘gold standard’ for serotyping pneumococci is the Quellung test. This technique is laborious and requires a certain level of training to correctly perform. Commercial pneumococcal latex agglutination serotyping reagents are available, but these are expensive. In-house production of latex agglutination reagents can be a cost-effective alternative to using commercially available reagents. This paper describes a method for the production and quality control (QC) of latex reagents, including problem solving recommendations, for pneumococcal serotyping. Results Here we describe a method for the production of latex agglutination reagents based on the passive adsorption of antibodies to latex particles. Sixty-five latex agglutination reagents were made using the PneuCarriage Project (PCP) method, of which 35 passed QC. The other 30 reagents failed QC due to auto-agglutination (n=2), no reactivity with target serotypes (n=8) or cross-reactivity with non-target serotypes (n=20). Dilution of antisera resulted in a further 27 reagents passing QC. The remaining three reagents passed QC when prepared without centrifugation and wash steps. Protein estimates indicated that latex reagents that failed QC when prepared using the PCP method passed when made with antiserum containing ≤ 500 μg/ml of protein. Sixty-one nasopharyngeal isolates were serotyped with our in-house latex agglutination reagents, with the results showing complete concordance with the Quellung reaction. Conclusions The method described here to produce latex agglutination reagents allows simple and efficient serotyping of pneumococci and may be applicable to latex agglutination reagents for typing or identification of other microorganisms. We recommend diluting antisera or removing centrifugation and wash steps for any latex reagents that fail QC. Our latex reagents are cost-effective, technically undemanding to prepare and remain stable for long periods of time, making them ideal for use in low-income countries.
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Abstract
Fungi and yeasts are critical causes of acute infection. As such, the detection and identification of these organisms are crucial in the diagnosis of affected patient populations. There is a vast array of commercial tests currently available for diagnostic purposes. These vary from traditional culture and biochemical methods to advanced multiparameter molecular tests. Recent technological advances have driven the development of rapid tests which are complementing and in some cases replacing the more traditional methods of detection. Irrespective of the method used the ultimate goal is timely detection of the infectious agent allowing appropriate treatment and improved outcome for the patient.
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Large-scale evaluation of the immuno-mycologics lateral flow and enzyme-linked immunoassays for detection of cryptococcal antigen in serum and cerebrospinal fluid. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 20:52-5. [PMID: 23114703 DOI: 10.1128/cvi.00536-12] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cryptococcosis is a systemic infection caused by the pathogenic yeasts Cryptococcus neoformans and C. gattii. Detection of cryptococcal capsular antigen (CrAg) in serum and cerebrospinal fluid (CSF) plays an important diagnostic role. We prospectively compared the new Immuno-Mycologics Inc. (IMMY) lateral flow assay (LFA) and enzyme immunoassay (EIA) to our current CrAg test (Premier EIA; Meridian Bioscience Inc.). Discordant samples were retested with the latex-Cryptococcus antigen test (IMMY) and using serotype-specific monoclonal antibodies (MAbs). A total of 589 serum and 411 CSF specimens were tested in parallel. Qualitative agreement across assays was 97.7%. In all, 56 (41 serum and 15 CSF) samples were positive and 921 (527 serum and 394 CSF) samples were negative by all three assays. The 23 discrepant specimens were all Meridian EIA negative. Of 23 discordant specimens, 20 (87.0%) were positive by both the IMMY LFA and EIA, 2 were LFA positive only, and 1 was EIA positive only. Eleven discrepant specimens had adequate volume for latex agglutination (LA) testing; 8 were LA positive, and 3 were LA negative. LA-negative samples (2 CSF samples and 1 serum) had low IMMY LFA/EIA titers (≤1:10). Serotype-specific MAb analysis of the LA-positive samples suggested that these specimens contained CrAg epitopes similar to those of serotype C strains. In conclusion, the IMMY assays showed excellent overall concordance with the Meridian EIA. Assay performance differences were related to issues of analytic sensitivity and possible serotype bias. Incomplete access to patient-level data combined with low specimen volumes limited our ability to fully resolve discrepant results.
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Comparison of four assays for the detection of cryptococcal antigen. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1988-90. [PMID: 23081814 DOI: 10.1128/cvi.00446-12] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We compared the performance of four assays for the detection of cryptococcal antigen in serum samples (n = 634) and cerebrospinal fluid (CSF) samples (n = 51). Compared to latex agglutination, the sensitivity and specificity of the Premier enzyme immunoassay (EIA), Alpha CrAg EIA, and CrAg lateral flow assay (LFA) were 55.6 and 100%, 100 and 99.7%, and 100 and 99.8%, respectively, from serum samples. There was 100% agreement among the four tests for CSF samples, with 18 samples testing positive by each of the assays.
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Effects of pretreating serum samples on the performance of a latex agglutination test for serodiagnosis of paracoccidioidomycosis. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2011; 19:386-90. [PMID: 22205661 DOI: 10.1128/cvi.05274-11] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Paracoccidioidomycosis (PCM) is a fungal disease caused by Paracoccidioides brasiliensis, and Brazil is one of the principal countries where it is endemic. Diagnosis is based on the observation of budding P. brasiliensis yeast in clinical specimens from patients; however, the sensitivity of the visualization of fungi is low, indicating that serological tests are used for early diagnosis. The double-immunodiffusion test (ID) is the "gold standard" test for serology in PCM, although the execution of this test requires the availability of laboratorial infrastructure. We report the improved performance of a latex agglutination test (LAT) by pretreating 30 serum samples from PCM patients and 71 controls (histoplasmosis and aspergillosis patients, patients with bacterial infections, and normal human sera) with a dilution buffer incubated at 37°C for 30 min. The sensitivity and specificity of the LAT test in the nonpretreated samples were 73% and 79%, respectively. However, when samples were pretreated, the sensitivity and specificity of the test increased to 90%. In this study, we did not observe cross-reactivity with histoplasmosis patient sera, but some reactions to sera from patients with aspergillosis and bacterial infections were noted. Normal human sera were not reactive in our tests. These results indicate the need for the elimination of heterologous reactions so that we can adequately use this method for screening cases of PCM.
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Abstract
Infections caused by the emerging pathogen Cryptococcus gattii are increasing in frequency in North America. During the past decade, interest in the pathogen has continued to grow, not only in North America but also in other areas of the world where infections have recently been documented. This review synthesizes existing data and raises issues that remain to be addressed.
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Affiliation(s)
- Julie Harris
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, MS C-09, Atlanta, GA 30309 USA.
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ECIL recommendations for the use of biological markers for the diagnosis of invasive fungal diseases in leukemic patients and hematopoietic SCT recipients. Bone Marrow Transplant 2011; 47:846-54. [DOI: 10.1038/bmt.2011.178] [Citation(s) in RCA: 203] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Ayats J, Martín-Mazuelos E, Pemán J, Quindós G, Sánchez F, García-Rodríguez J, Guarro J, Guinea J, Linares MJ, Pontón J, Rodríguez-Tudela JL, Cuenca-Estrella M. Recomendaciones sobre el diagnóstico de la enfermedad fúngica invasora de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica (SEIMC). Actualización 2010. Enferm Infecc Microbiol Clin 2011; 29:39.e1-15. [DOI: 10.1016/j.eimc.2010.08.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Accepted: 08/18/2010] [Indexed: 12/21/2022]
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Lau A, Chen S, Sleiman S, Sorrell T. Current status and future perspectives on molecular and serological methods in diagnostic mycology. Future Microbiol 2009; 4:1185-222. [DOI: 10.2217/fmb.09.70] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Invasive fungal infections are an important cause of infectious morbidity. Nonculture-based methods are increasingly used for rapid, accurate diagnosis to improve patient outcomes. New and existing DNA amplification platforms have high sensitivity and specificity for direct detection and identification of fungi in clinical specimens. Since laboratories are increasingly reliant on DNA sequencing for fungal identification, measures to improve sequence interpretation should support validation of reference isolates and quality control in public gene repositories. Novel technologies (e.g., isothermal and PNA FISH methods), platforms enabling high-throughput analyses (e.g., DNA microarrays and Luminex® xMAP™) and/or commercial PCR assays warrant further evaluation for routine diagnostic use. Notwithstanding the advantages of molecular tests, serological assays remain clinically useful for patient management. The serum Aspergillus galactomannan test has been incorporated into diagnostic algorithms of invasive aspergillosis. Both the galactomannan and the serum β-D-glucan test have value for diagnosing infection and monitoring therapeutic response.
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Affiliation(s)
- Anna Lau
- Centre for Infectious Diseases & Microbiology, University of Sydney, Sydney, Australia
| | - Sharon Chen
- Centre for Infectious Diseases & Microbiology, University of Sydney, Sydney, Australia and Centre for Infectious Diseases & Microbiology Laboratory Services, Institute of Clinical Pathology & Medical Research, Westmead Hospital, Westmead, NSW 2145, Australia
| | - Sue Sleiman
- Centre for Infectious Diseases & Microbiology Laboratory Services, Institute of Clinical Pathology & Medical Research, Westmead Hospital, Westmead, NSW 2145, Australia
| | - Tania Sorrell
- Centre for Infectious Diseases & Microbiology, Westmead Hospital, Darcy and Hawkesbury Roads, Westmead, NSW 2145, Australia
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