Browsing by Author "Beissner, Marcus"

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    Comparison of Two Assays for Molecular Determination of Rifampin Resistance in Clinical Samples from Patients with Buruli Ulcer Disease
    (Journal of Clinical Microbiology, 2014-01-29) Phillips, Richard Odame; Jansson, Moritz; Beissner, Marcus; Badziklou, Kossi; Piten, Ebekalisai; et. al
    Buruli ulcer disease (BUD), caused by Mycobacterium ulcerans, involves the skin, subcutaneous fatty tissue, and bones and predominantly affects children 15 years of age. If left untreated, contractures may cause severe functional limitation. Standardized antimycobacterial treatment consists of rifampin (RMP) and streptomycin administered for 8 weeks. An oral regimen combiningRMPand clarithromycin is currently under clinical evaluation (1–3). Notwithstanding the efficiency of chemotherapy, treatment failures and various types of secondary lesions have been reported, suggesting the need for customized clinical management strategies (4–6).
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    Detection of Viable Mycobacterium ulcerans in Clinical Samples by a Novel Combined 16S rRNA Reverse Transcriptase/IS2404 Real-Time qPCR Assay
    (PLOS Neglected Tropical Diseases, 2012-08-28) Phillips, Richard Odame; Beissner, Marcus; Symank, Dominik; Amoako, Yaw Ampem; Awua-Boateng, Nana- Yaa; et. al
    Buruli ulcer disease (BUD) caused by Mycobacterium ulcerans involves the skin and soft tissue. If left untreated, extensive destruction of tissue followed by scarring and contractures may lead to severe functional limitations. Following the introduction of standardized antimycobacterial chemotherapy with rifampicin and streptomycin, recurrence rates of less than 2% were reported. However, treatment failures occur and a variety of secondary lesions necessitating customized clinical management strategies have been reported. True recurrences by definition occur more than three months after completion of antibiotic treatment, are characterised by the presence of viable bacilli, and require a second course of antibiotics. ‘‘Non-healers’’ may harbour viable, possibly drug-resistant M. ulcerans strains and may benefit from surgical intervention. Early-onset immune-mediated paradoxical reactions emerging during or shortly after treatment do not contain viable bacilli and may heal under conventional wound care and/or minor surgery; lateonset secondary lesions presumably attributable to secondary infection foci may clear spontaneously through enhanced immune responses primed by initial treatment. None of the current diagnostic techniques is applicable to rapidly address the pivotal question of the presence of viable bacilli in non-healers and patients with secondary BUD lesions, and optimal time points for collection of follow-up samples have not yet been investigated. Therefore, to date treatment monitoring is mainly based on clinical observation [1– 5]. Reverse transcriptase assays targeting 16S rRNA and mRNA were successfully applied for the rapid detection of viable mycobacteria in clinical samples from patients with tuberculosis and leprosy [6,7]. To employ this technique for classification of BUD lesions and monitoring of treatment success we developed a M. ulcerans–specific RNA-based viability assay combining a 16S rRNA reverse transcriptase real-time PCR (RT-qPCR) to determine bacterial viability with an IS2404 quantitative real-time PCR (qPCR) for increased specificity and simultaneous quantification of bacilli.
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    Infection with Mansonella perstans Nematodes in Buruli Ulcer Patients, Ghana
    (Emerging Infectious Diseases, 2014-06-06) Phillips, Richard Odame; Frimpong, Michael; Sarfo, Fred Stephen; Kretschmer, Birte; Beissner, Marcus; et. al
    During August 2010–December 2012, we conducted a study of patients in Ghana who had Buruli ulcer, caused by Mycobacterium ulcerans, and found that 23% were coinfected with Mansonella perstans nematodes; 13% of controls also had M. perstans infection. M. perstans co-infection should be considered in the diagnosis and treatment of Buruli ulcer.
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    Loop-Mediated Isothermal Amplification for Laboratory Confirmation of Buruli Ulcer Disease—Towards a Point-of-Care Test
    (PLOS Neglected Tropical Diseases, 2015-11-13) Beissner, Marcus; Phillips, Richard Odame; Battke, Florian; Bauer, Malkin; Badziklou, Kossi; et. al
    As the major burden of Buruli ulcer disease (BUD) occurs in remote rural areas, development of point-of-care (POC) tests is considered a research priority to bring diagnostic services closer to the patients. Loop-mediated isothermal amplification (LAMP), a simple, robust and cost-effective technology, has been selected as a promising POC test candidate. Three BUD-specific LAMP assays are available to date, but various technical challenges still hamper decentralized application. To overcome the requirement of cold-chains for transport and storage of reagents, the aim of this study was to establish a dry-reagentbased LAMP assay (DRB-LAMP) employing lyophilized reagents.