A rapid bio‐optical sensor for diagnosing Q fever in clinical specimens

Abstract

Recent zoonotic outbreaks, such as Zika, Middle East respiratory syndrome and Ebola, have highlighted the need for rapid and accurate diagnostic assays that can be used to aid pathogen control. Q fever is a zoonotic disease caused by the transmission of Coxiella burnetii that can cause serious illness in humans through aerosols and is considered a potential bioterrorism agent. However, the existing assays are not suitable for the detection of this pathogen due to its low levels in real samples. We here describe a rapid bio-optical sensor for the accurate detection of Q fever and validate its clinical utility. By combining a bio-optical sensor, that transduces the presence of the target DNA based on binding-induced changes in the refractive index on the waveguide surface in a label-free and real-time manner, with isothermal DNA amplification, this new diagnostic tool offers a rapid (<20 min), 1-step DNA amplification/detection method. We confirmed the clinical sensitivity (>90%) of the bio-optical sensor by detecting C. burnetii in 11 formalin-fixed, paraffin-embedded liver biopsy samples from acute Q fever hepatitis patients and in 16 blood plasma samples from patients in which Q fever is the cause of fever of unknown origin.

Review: a comprehensive summary of a decade development of the recombinase polymerase amplification

“…Detection of RPA reactions can also be performed using silicon microring resonator (SMR)-based photonic detection, which involves performing nucleic acid amplification in an asymmetric manner ( pre-immobilised on one of the primers on the SMR, and all the other oligonucleotides and reagents are free in the solution, see also section 4.2) in the evanescent field of a resonator waveguide. [173][174][175] The binding of nucleic acids to pre-immobilised primers induces changes in the refractive index proximal to the waveguide surface. As the nucleic acid amplification progresses, the wavelength shift due to binding can be monitored in real-time on the SMR (Fig.…”

Detection of Coxiella burnetii Using Silicon Microring Resonator in Patient Blood Plasma

“…Furthermore, we described several novelties regarding the SMR sensor for diagnosing Q fever compared to the previous study. In our previous proof-of-concept study, the SMR sensor was more sensitively developed for the detection of C. burnetii than conventional methods for Q fever diagnosis using frozen formaldehyde-fixed paraffin-embedded tissue and frozen blood plasma specimens from the Q fever patients [29,30]. On the other hand, in this study, we first optimized the sensor for a rapid and accurate diagnosis of Q fever in prospectively collected fresh blood plasma specimens (Figure 1).…”

Development of key quality indicators for appropriate antibiotic use in the Republic of Korea: results of a modified Delphi survey

“…Another advantage is that the same criteria can be applied every year to determine whether one's institution has improved. In Australia, four key QIs (documentation of indication, documentation of review or stop date, surgical prophylaxis for > 24 hours and noncompliance with guidelines) and inappropriate antibiotic prescription rates are presented annually along with the target levels [8]. Based on the collected data, the researchers could identify priority areas for targeted quality improvement initiatives directed toward antimicrobial prescribing patterns.…”

“…In 2018, the European Surveillance of Antimicrobial Consumption group developed QIs to evaluate appropriate antibiotic use in inpatients and outpatients in Europe [6,7]. In Australia, surveillance of appropriate antibiotic use has been conducted since 2011, and key indicators have been developed [8]; results of appropriate antibiotic use have been generated through national surveillance every year using the key indicators. Nonetheless, it is important to evaluate appropriate antibiotic use with standard criteria, which can then be directly compared between medical institutions, and provides feedback to generate suggestions to improve the goals of national antibiotic stewardship.…”