Leishmania-FAST15: A rapid, sensitive and low-cost real-time PCR assay for the detection of Leishmania infantum and Leishmania braziliensis kinetoplast DNA in canine blood samples

Introduction: Invasive aspergillosis is a severe complication of cytotoxic chemotherapies and bone marrow transplantation (BMT). The aim of this study was to assess the utility of a real-time PCR assay for the early diagnosis of Aspergillus species in blood samples from BMT patients. Methodology: Blood specimens (n = 993) from patients (n = 82) scheduled for BMT were collected prior to transplant and for 100 days post transplantation. The specimens were later tested using an Aspergillus-specific real-time PCR assay. Cultures of clinical samples, along with sonography and computerized tomographic scans, were performed as standard of care. Results: Aspergillus DNA was positive in 94 sequential blood samples from 13 patients with clinical and radiological signs of infection. Samples from three of these patients were PCR-positive for Aspergillus in the first week of admission, prior to transplantation. Four patients with aspergillosis were cured with antifungal agents and nine died. An additional 12 patients without clinical signs of infection were PCR-positive on one occasion each, while two patients with clinical signs of infection were PCR-negative. Compared to routine methods of aspergillosis diagnosis, the respective sensitivity, specificity, negative, and positive predictive values of the PCR method by patient were 86.6%, 82%, 96.5% and 52%. Conclusions: The results show that Aspergillus infections in the blood of bone marrow transplant patients can be dectected by PCR methods. Early detection of Aspergillus infections by PCR has the potential to positively impact patient mortality rate and provide cost savings to hospitals.

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Quantification of Leishmania infantum DNA by a Real-Time PCR Assay with High Sensitivity

Journal of Clinical Microbiology ◽

10.1128/jcm.42.11.5249-5255.2004 ◽

2004 ◽

Vol 42 (11) ◽

pp. 5249-5255 ◽

Cited By ~ 248

Author(s):

C. Mary ◽

F. Faraut ◽

L. Lascombe ◽

H. Dumon

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Leishmania Infantum ◽

High Sensitivity ◽

Pcr Assay

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Toward point-of-care diagnostics of Candida auris

10.1101/2020.02.10.20021683 ◽

2020 ◽

Cited By ~ 1

Author(s):

Geoffrey Mulberry ◽

Sudha Chaturvedi ◽

Vishnu Chaturvedi ◽

Brian N. Kim

Keyword(s):

New York ◽

Real Time ◽

Real Time Pcr ◽

Positive Impact ◽

Point Of Care ◽

Low Cost ◽

High Sensitivity ◽

Clinical Samples ◽

Pcr Assay ◽

Candida Auris

AbstractCandida auris is a multidrug-resistant yeast that presents global health threat for the hospitalized patients. Early diagnostic of C. auris is crucial in control, prevention, and treatment. Candida auris is difficult to identify with standard laboratory methods and often can be misidentified leading to inappropriate management. A newly-devised real-time PCR assay played an important role in the ongoing investigation of the C. auris outbreak in New York metropolitan area. The assay can rapidly detect C. auris DNA in surveillance and clinical samples with high sensitivity and specificity, and also useful for confirmation of C. auris cultures. Despite its positive impact, the real-time PCR assay is difficult to deploy at frontline laboratories due to high-complexity set-up and operation. Using a low-cost handheld real-time PCR device, we show that the C. auris can potentially be identified in a low-complexity assay without the need for high-cost equipment. An implementation of low-cost real-time PCR device in hospitals and healthcare facilities is likely to accelerate the diagnosis of C. auris and for control of the global epidemic.

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Evaluating Performance of Multiplex Real Time PCR for the Diagnosis of Malaria at Elimination Targeted Low Transmission Settings of Ethiopia.

10.21203/rs.3.rs-572301/v1 ◽

2021 ◽

Author(s):

Mahlet Belachew ◽

Mistire Wolde ◽

Desalegn Nega ◽

Bokretsion Gidey ◽

Legessie Negash ◽

...

Keyword(s):

Light Microscopy ◽

Real Time ◽

Malaria Elimination ◽

Real Time Pcr ◽

Nucleic Acid Amplification ◽

Molecular Testing ◽

Pcr Assay ◽

Blood Samples ◽

Low Transmission ◽

Highly Sensitive

Abstract Background: Malaria incidence has declined in Ethiopia in the past ten years. Current malaria diagnostic tests, including light microscopy and antigen-detecting rapid tests (RDTs) cannot reliably detect low-density infections. Studies have shown that nucleic acid amplification tests are highly sensitive and specific in detecting malaria infection. Thus, this study took place with the aim of evaluating the performance of multiplex real time PCR for the diagnosis of malaria using patient samples collected from health facilities located at malaria elimination targeted low transmission settings in Ethiopia. Methods: A health facility based cross sectional survey was conducted in selected malaria sentinel sites. Malaria suspected febrile outpatients referred to laboratory for malaria testing between December 2019 and March 2020 were enrolled into this study. Socio demographic information and capillary blood samples were collected from the study participants and tested at spot with RDTs. Additionally, five circles of dry blood sample (DBS) samples on Whatman filter paper and thick and thin smear were prepared for molecular testing and microscopic examination, respectively. Multiplex real time PCR assay was performed at EPHI malaria laboratory. The performance of multiplex real time PCR assay, microscopy and RDT for the diagnosis of malaria was compared and evaluated against each other.Results: Out of 271 blood samples, multiplex real time PCR identified 69 malaria cases as P. falciparum infection, 16 as P. vivax and 3 as mixed infections. Of the total samples, light microscopy detected 33 as Pf, 18 as PV and RDT detected 43 as Pf, 17 as PV, and one mixed infection. Using light microscopy as reference test, the sensitivity and specificity of multiplex real time PCR were 100% (95% CI [93-100]) and 83.2% (95% CI [77.6-87.9]), respectively. Using multiplex real time PCR as a reference, light microscopy and RDT had sensitivity of 58% (95% CI [46.9-68.4] and 67% (95% CI [56.2-76.7]); and 100% (95% CI [98-100] and 98.9 (95% CI (96-99.9), respectively. Substantial level of agreement was reported between microscopy and multiplex real time PCR results with kappa value of 0.65. Conclusions: Multiplex real time PCR had an advanced performance in parasite detection and species identification on febrile patients’ samples than did microscopy and RDT in low malaria transmission settings. It is highly sensitive malaria diagnostic method that can be used in malaria elimination program, particularly for community based epidemiological samples. Although microscopy and RDT had reduced performance when compared to multiplex real time PCR, still had an acceptable performance in diagnosis of malaria cases on patient samples at clinical facilities.

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