scholarly journals Detecting Azole-Antifungal Resistance in Aspergillus fumigatus by Pyrosequencing

2020 ◽  
Vol 6 (1) ◽  
pp. 12 ◽  
Author(s):  
Mireille H. van der Torre ◽  
Lilyann Novak-Frazer ◽  
Riina Rautemaa-Richardson
Keyword(s):  
Dna Sequencing ◽  
Susceptibility Testing ◽  
Simultaneous Detection ◽  
Drug Susceptibility ◽  
Turnaround Time ◽  
Fungal Species ◽  
Antifungal Resistance ◽  
Diagnostic Methods ◽  
Resistance Testing ◽  
Clinical Samples

Guidelines on the diagnosis and management of Aspergillus disease recommend a multi-test approach including CT scans, culture, fungal biomarker tests, microscopy and fungal PCR. The first-line treatment of confirmed invasive aspergillosis (IA) consists of drugs in the azole family; however, the emergence of azole-resistant isolates has negatively impacted the management of IA. Failure to detect azole-resistance dramatically increases the mortality rates of azole-treated patients. Despite drug susceptibility tests not being routinely performed currently, we suggest including resistance testing whilst diagnosing Aspergillus disease. Multiple tools, including DNA sequencing, are available to screen for drug-resistant Aspergillus in clinical samples. This is particularly beneficial as a large proportion of IA samples are culture negative, consequently impeding susceptibility testing through conventional methods. Pyrosequencing is a promising in-house DNA sequencing method that can rapidly screen for genetic hotspots associated with antifungal resistance. Pyrosequencing outperforms other susceptibility testing methods due to its fast turnaround time, accurate detection of polymorphisms within critical genes, including simultaneous detection of wild type and mutated sequences, and—most importantly—it is not limited to specific genes nor fungal species. Here we review current diagnostic methods and highlight the potential of pyrosequencing to aid in a diagnosis complete with a resistance profile to improve clinical outcomes.

scholarly journals The Use of a Shared Services Model for Mycobacteriology Testing: Lessons Learned

2017 ◽  
Vol 133 (1) ◽  
pp. 93-99
Author(s):  
Cortney Stafford ◽  
Robyn Atkinson-Dunn ◽  
Sarah N. Buss ◽  
Tracy Dalton ◽  
Debbie Gibson ◽  
...  
Keyword(s):  
Public Health ◽  
Drug Resistance ◽  
Molecular Detection ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Turnaround Time ◽  
Drug Susceptibility Testing ◽  
Health Concern ◽  
Resistance Testing ◽  
Shared Services

Objectives: Public health laboratories (PHLs) provide essential services in the diagnosis and surveillance of diseases of public health concern, such as tuberculosis. Maintaining access to high-quality laboratory testing is critical to continued disease detection and decline of tuberculosis cases in the United States. We investigated the practical experience of sharing tuberculosis testing services between PHLs through the Shared Services Project. Methods: The Shared Services Project was a 9-month-long project funded through the Association of Public Health Laboratories and the Centers for Disease Control and Prevention during 2012-2013 as a one-time funding opportunity to consortiums of PHLs that proposed collaborative approaches to sharing tuberculosis laboratory services. Submitting PHLs maintained testing while simultaneously sending specimens to reference laboratories to compare turnaround times. Results: During the 9-month project period, 107 Mycobacterium tuberculosis complex submissions for growth-based drug susceptibility testing and molecular detection of drug resistance testing occurred among the 3 consortiums. The median transit time for all submissions was 1.0 day. Overall, median drug susceptibility testing turnaround time (date of receipt in submitting laboratory to result) for parallel testing performed in house by submitting laboratories was 31.0 days; it was 43.0 days for reference laboratories. The median turnaround time for molecular detection of drug resistance results was 1.0 day (mean = 2.8; range, 0-14) from specimen receipt at the reference laboratories. Conclusions: The shared services model holds promise for specialized tuberculosis testing. Sharing of services requires a balance among quality, timeliness, efficiency, communication, and fiscal costs.

scholarly journals Development and application of two multiplex real-time PCR assays for detection and speciation of bacterial pathogens in the koala

2018 ◽  
Vol 30 (4) ◽  
pp. 523-529 ◽  
Author(s):  
Lyndal S. Hulse ◽  
Danica Hickey ◽  
Jessica M. Mitchell ◽  
Kenneth W. Beagley ◽  
William Ellis ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Bacterial Pathogens ◽  
Simultaneous Detection ◽  
Turnaround Time ◽  
Clinical Samples ◽  
Phascolarctos Cinereus ◽  
In The Wild ◽  
Labeled Probe ◽  
Free Ranging

Infectious diseases have contributed to the decline in the health of koala ( Phascolarctos cinereus) populations in the wild in some regions of Australia. Herein we report the development and validation of 2 multiplex real-time PCR (rtPCR) panels for the simultaneous detection of Mycoplasma spp., Ureaplasma spp., Bordetella bronchiseptica, and Chlamydia, including speciation and quantification of Chlamydia, in ocular, reproductive, and nasal swab samples in addition to semen and male urogenital and reproductive tissues, from koalas. Each rtPCR panel was developed for use as a single-tube reaction using pathogen-specific primers and fluorescently labeled probe sets. DNA extracted from reference strains and isolates was used for validation of sequence gene targets for the multiplex rtPCR panels. Each panel was shown to be sensitive and specific in detecting and differentiating the bacterial pathogens. The multiplex rtPCR panels were used to screen clinical samples from free-ranging and hospitalized koalas for multiple pathogens simultaneously. The multiplex rtPCR will improve turnaround time compared to individual-pathogen rtPCR methods used, to date, for confirmation of diagnosis and will provide the wildlife clinician with the ability to make treatment decisions more rapidly.

scholarly journals Performance of the TruGene Human Immunodeficiency Virus Type 1 Genotyping Kit and OpenGene DNA Sequencing System on Clinical Samples Diluted to Approximately 100 Copies per Milliliter

2006 ◽  
Vol 13 (2) ◽  
pp. 235-238 ◽  
Author(s):  
Howard B. Gale ◽  
Virginia L. Kan ◽  
Rebecca C. Shinol
Keyword(s):  
Human Immunodeficiency Virus ◽  
Dna Sequencing ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Rna Extraction ◽  
Pcr Amplification ◽  
Resistance Testing ◽  
Clinical Samples ◽  
Immunodeficiency Virus

ABSTRACT The TruGene human immunodeficiency virus type 1 (HIV-1) genotyping kit/OpenGene DNA sequencing system (Bayer HealthCare, Tarrytown, NY) reliably produced clinically acceptable resistance profiles for reverse transcriptase and protease inhibitors on patient samples diluted to ∼100 copies/ml following extraction with the QIAamp viral RNA minikit (QIAGEN Inc., Valencia, CA). One modification of the standard protocol was made to guarantee PCR amplification: a centrifugation step to concentrate virus was added before RNA extraction. For genotypic antiretroviral resistance testing, no significant differences in the identification and sensitivity of detection for codon mutations, base mutations, and multibase sites were found between the original and diluted samples.

scholarly journals Molecular Detection of Mutations Associated with First- and Second-Line Drug Resistance Compared with Conventional Drug Susceptibility Testing of Mycobacterium tuberculosis

2011 ◽  
Vol 55 (5) ◽  
pp. 2032-2041 ◽  
Author(s):  
Patricia J. Campbell ◽  
Glenn P. Morlock ◽  
R. David Sikes ◽  
Tracy L. Dalton ◽  
Beverly Metchock ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Dna Sequencing ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Second Line ◽  
First Line ◽  
Content Type ◽  
Line Drug

ABSTRACTThe emergence of multi- and extensively drug-resistant tuberculosis is a significant impediment to the control of this disease because treatment becomes more complex and costly. Reliable and timely drug susceptibility testing is critical to ensure that patients receive effective treatment and become noninfectious. Molecular methods can provide accurate and rapid drug susceptibility results. We used DNA sequencing to detect resistance to the first-line antituberculosis drugs isoniazid (INH), rifampin (RIF), pyrazinamide (PZA), and ethambutol (EMB) and the second-line drugs amikacin (AMK), capreomycin (CAP), kanamycin (KAN), ciprofloxacin (CIP), and ofloxacin (OFX). Nine loci were sequenced:rpoB(for resistance to RIF),katGandinhA(INH),pncA(PZA),embB(EMB),gyrA(CIP and OFX), andrrs,eis, andtlyA(KAN, AMK, and CAP). A total of 314 clinicalMycobacterium tuberculosiscomplex isolates representing a variety of antibiotic resistance patterns, genotypes, and geographical origins were analyzed. The molecular data were compared to the phenotypic data and the accuracy values were calculated. Sensitivity and specificity values for the first-line drug loci were 97.1% and 93.6% forrpoB, 85.4% and 100% forkatG, 16.5% and 100% forinhA, 90.6% and 100% forkatGandinhAtogether, 84.6% and 85.8% forpncA, and 78.6% and 93.1% forembB. The values for the second-line drugs were also calculated. The size and scope of this study, in numbers of loci and isolates examined, and the phenotypic diversity of those isolates support the use of DNA sequencing to detect drug resistance in theM. tuberculosiscomplex. Further, the results can be used to design diagnostic tests utilizing other mutation detection technologies.

scholarly journals Phenotypic and molecular characterization of pyrazinamide resistance among multidrug-resistant Mycobacterium tuberculosis isolates in Ningbo, China

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yang Che ◽  
Dingyi Bo ◽  
Xiang Lin ◽  
Tong Chen ◽  
Tianfeng He ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Dna Sequencing ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Mdr Tb ◽  
Resistant Group ◽  
Susceptible Group

Abstract Background Detection of pyrazinamide (PZA) resistance in Mycobacterium tuberculosis (TB) patients is critical, especially in dealing with multidrug-resistant Mycobacterium tuberculosis (MDR-TB) case. Up to date, PZA drug susceptibility testing (DST) has not been regularly performed in China. The prevalence and molecular characteristics of PZA resistance in M.tuberculosis isolates, especially MDR-TB have not been studied in Ningbo, China. This study aimed to analyze the phenotypic and molecular characterization of PZA resistance among MDR-TB isolates in Ningbo. Methods A total of 110 MDR-TB isolates were collected from the TB patients who were recorded at local TB dispensaries in Ningbo. All clinical isolates were examined by drug susceptibility testing and genotyping. DNA sequencing was used to detect mutations in the pncA gene associated with PZA resistance. Results The prevalence of PZA resistance among MDR-TB strains in Ningbo was 59.1%. With regard to the history and the outcome of treatments among MDR-TB cases, the percentages of re-treated MDR-TB patients in the PZA-resistant group and of successful patients in PZA-susceptible group were significantly higher than the ones in the PZA-susceptible group and in the PZA-resistant group, respectively (P = 0.027, P = 0.020). The results showed that the resistance of streptomycin (67.7% vs 46.7%, P = 0.027), ethambutol (56.9% vs 33.3%, P = 0.015), ofloxacin (43.1% vs 11.1%, P = 0.000), levofloxacin (43.1% vs 11.1%, P = 0.000), pre-XDR (pre-Xtensively Drug Resistance) (38.5% vs 15.6%, P = 0.009), were more frequently adverted among PZA-resistant isolates compared with PZA-susceptible isolates. In addition, 110 MDR-TB was composed of 87 (PZA resistant, 78.5%) Beijing strains and 23 (PZA resistant, 21.5%) non-Beijing strains. Fifty-four out of 65 (83.1%) PZA-resistant MDR strains harbored a mutation located in the pncA gene and the majority (90.7%) were point mutations. Compared with the phenotypic characterization, DNA sequencing of pncA has sensitivity and specificity of 83.1 and 95.6%. Conclusion The mutations within pncA gene was the primary mechanism of PZA resistance among MDR-TB and DNA sequencing of pncA gene could provide a rapid detection evidence in PZA drug resistance of MDR-TB in Ningbo.

scholarly journals Prediction of cephalosporin and carbapenem susceptibility in multi-drug resistant Gram-negative bacteria using liquid chromatography-tandem mass spectrometry

2017 ◽  
Author(s):  
Yuiko Takebayashi ◽  
Wan Ahmad Kamil Wan Nur Ismah ◽  
Jacqueline Findlay ◽  
Kate J. Heesom ◽  
Jay Zhang ◽  
...  
Keyword(s):  
Clinical Decision Making ◽  
Susceptibility Testing ◽  
Bacterial Species ◽  
Clinical Decision ◽  
Drug Susceptibility ◽  
Clinical Samples ◽  
Correct Prediction ◽  
Antibacterial Drug ◽  
Liquid Chromatography Tandem Mass

ABSTRACTIn vitro antibacterial susceptibility testing informs clinical decision making concerning antibacterial therapeutics. Predicting, in a timely manner, which bacterial infection will respond to treatment by a given antibacterial drug reduces morbidity, mortality, and healthcare costs. It also allows prudent antibacterial use, because clinicians can focus on the least broad-spectrum agent suitable for each patient. Existing susceptibly testing methodologies rely on growth of bacteria in the presence of an antibacterial drug. There is significant interest in the possibility of predicting antibacterial drug susceptibility directly though the analysis of bacterial DNA or protein, because this may lead to more rapid susceptibility testing directly from clinical samples. Here we report a robust and tractable methodology that allows measurement of the abundance of key proteins responsible for antibacterial drug resistance within samples of 1 µg of total bacterial protein. The method allowed correct prediction of β-lactam susceptibility in clinical isolates from four key bacterial species and added considerable value over and above the information generated by whole genome sequencing, allowing for gene expression, not just gene presence to be considered, which is key when considering the complex interplays of multiple mechanisms of resistance.

scholarly journals Testing Susceptibility of M. tuberculosis to Second Line Anti-Tuberculosis Drugs Using the XDR Test in Clinical Trials and International Professional Testing Cycles

2021 ◽  
Vol 99 (8) ◽  
pp. 13-20
Author(s):  
L. V. Domotenko ◽  
T. P. Morozova ◽  
M. V. Khramov ◽  
А. P. Shepelin
Keyword(s):  
Clinical Trials ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
World Health ◽  
Clinical Samples ◽  
Second Line ◽  
Tuberculosis Patients ◽  
Testing Susceptibility ◽  
Health Organization

The objective of the study: to evaluate the commercial XDR test for susceptibility testing of M. tuberculosis to second line anti-tuberculosis drugs in clinical trials and as part of annual professional testing cycles coordinated by the World Health Organization (WHO).Subjects and Methods. Cultures of M. tuberculosis (n = 90) freshly isolated on egg media from clinical samples collected in tuberculosis patients were tested using the Bactec MGIT 960 system and the XDR test under identical conditions. Well-studied strains of M. tuberculosis (n = 216) obtained from the WHO supranational laboratories were repeatedly cultured on Middlebrook 7H10 medium before the study. The drug susceptibility of the cultures was assessed using the XDR test by the nitrate reductase method.Results. A high concurrence (96.7-100%) of the results was shown when testing susceptibility of 90 M. tuberculosis isolates to kanamycin, amikacin, capreomycin and ofloxacin using the XDR test and the Bactec MGIT 960 system with comparable test periods. The use of the XDR test for drug susceptibility testing of 216 M. tuberculosis strains in eleven annual professional testing cycles coordinated by the WHO supranational laboratories provided the results consistent with the consensus one for kanamycin, capreomycin, ofloxacin and amikacin in 98.6, 99.4, 99.4, and 99.0% of cases, respectively. For moxifloxacin and levofloxacin additionally incorporated to the XDR test, completely identical results were obtained.

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