Syndromic Testing

What PCR method is the BioFire FilmArray system primarily based on?

• Polymerase chain reaction

• Nested Multiplex PCR with HRM Curve

• Multiplex PCR

• TaqMan probes based PCR

Answer explanation

The BioFire® System is an automated in vitro diagnostic (IVD) system that utilizes nmPCR and high-resolution melting analysis to detect and identify multiple nucleic acid targets from clinical specimens.

 

Nested Multiplex PCR nmPCR uses two stages of PCR. During the first-stage PCR, multiple “outer primers” are used to perform multiplex PCR on the target templates present in the sample.

Second-stage PCR is performed in a singleplex format to further amplify the DNA copies generated during the first-stage PCR. The “inner primers” used in second-stage PCR are made up of sequences “nested” within the first-stage PCR product(s).

In nested PCR, what does the use of inner or nested primers in the second round of amplification primarily contribute to?

• Increased reaction speed

• Decreased sensitivity

• Enhanced specificity

• Increased sensitivity

Answer explanation

Nested PCR usually involves two sequential amplification reactions, each of which uses a different pair of primers. The product of the first amplification reaction is used as the template for the second PCR, which is primed by oligonucleotides that are placed internal to the first primer pair. The use of two pairs of oligonucleotides allows a higher number of cycles to be performed, thereby increasing the sensitivity of the PCR.

Green MR, Sambrook J. Nested Polymerase Chain Reaction (PCR).

Cold Spring Harb Protoc. 2019 Feb 1;2019(2). doi: 10.1101/pdb.prot095182. PMID: 30710024.

In which of the following scenarios is nested PCR often the method of choice?

• Routine amplification of a well-characterized DNA fragment

• Detection of common genetic mutations

• Identification of rare genetic variants or low-copy-number DNA

• DNA quantification for PCR standards

What is the primary reason for using two sets of primers in nested PCR?

• To accelerate the PCR process

• To reduce the amount of DNA required

• To enhance the specificity of the PCR amplification

• To increase the reaction temperature

Answer explanation

The improved specificity of the reaction derives from the binding of two separate sets of primers to the same target template. Nested PCR is an efficient method to amplify segments of long templates but requires knowledge of the sequence of the target.

Why is USFDA certification important for medical devices and pharmaceutical products?

• To ensure they are cost-effective.

• To facilitate international trade.

• To verify their clinical efficacy and safety.

• To reduce production costs.

Answer explanation

USFDA (United States Food and Drug Administration) certification, or more accurately, FDA approval or clearance, is critically important for medical devices and pharmaceutical products for several reasons:

Patient Safety: The FDA's primary mission is to protect public health by ensuring the safety and efficacy of medical products. FDA approval signifies that a product has undergone rigorous testing and evaluation, reducing the risk of harm to patients.

Quality Assurance: FDA certification requires strict adherence to quality control and manufacturing standards. This promotes consistent and high-quality products in the market.

Clinical Evidence: The FDA demands extensive clinical data to support claims of safety and efficacy. This evidence is important not just for regulatory approval but also for building trust with healthcare professionals and consumers.

Insurance Coverage: In many cases, medical devices and pharmaceutical products must have FDA approval to be eligible for insurance reimbursement. Without it, patients may have to pay out of pocket for these products.

Legal and Liability Protection: For manufacturers, obtaining FDA certification can provide some legal protection. If a product is FDA-approved and used as directed, it may be easier for the manufacturer to defend against liability claims.

Research Funding: Researchers and companies often require FDA approval to conduct clinical trials and receive research funding, which is essential for the development of new medical devices and pharmaceuticals.

In summary, USFDA certification is vital for ensuring patient safety, market access, and product quality. It also provides a competitive advantage, facilitates insurance coverage and international market access, and is important for legal protection and research funding.

What is the primary advantage of syndromic testing for patients with infectious diseases?

• Delayed diagnosis

• Increased risk of antibiotic resistance

• Rapid and accurate diagnosis

• longer hospital stays

Answer explanation

Syndromic testing identifies the infectious agents responsible for a patient's symptoms. By knowing the specific pathogens, healthcare professionals can target treatments more accurately, differentiating between viral and bacterial infections and ensuring antibiotics are used correctly and not unnecessarily.

How does syndromic testing help reduce unnecessary antibiotic use in patients?

• By promoting the use of antibiotics for all infections

• By prescribing antibiotics without testing

• By distinguishing between viral and bacterial infections

• By delaying treatment decisions

Answer explanation

Determining the cause of a viral infection, even if there is no specific treatment for it, can help healthcare providers avoid unnecessary antibiotics, reduce hospital length-of-stay, and improve patient satisfaction.

The BioFire System also detects parasites and fungi for relevant syndromes, which helps healthcare providers determine a causative agent sooner to avoid guesswork and downstream testing.

Additionally, identifying antimicrobial resistance genes can promote antimicrobial stewardship and facilitate more informed patient management decisions.

(BioFire Diagnostics, 2022)

Săndulescu O, Streinu-Cercel A, Moțoi MM, Streinu-Cercel A, Preoțescu LL. Syndromic Testing in Infectious Diseases: From Diagnostic Stewardship to Antimicrobial Stewardship. Antibiotics. 2023; 12(1):6. https://doi.org/10.3390/antibiotics12010006

What is the impact of syndromic testing on hospital stays for patients with infectious diseases?

• It prolongs hospital stays.

• It has no effect on hospital stays.

• It leads to shorter hospital stays.

• It only benefits healthcare providers.

Answer explanation

Syndromic diagnostic testing is a novel approach to the rapid diagnosis of common infectious diseases, including bloodstream, respiratory, gastrointestinal, and CNS infections. As the global burden of antimicrobial resistance continues to rise, the judicious use of antimicrobials is of utmost importance. Syndromic panels, if implemented thoughtfully and interpreted carefully, have the potential to improve antimicrobial use and patient outcomes through improved clinical decision making, optimized laboratory workflow, and enhanced antimicrobial and laboratory stewardship.

Dumkow LE, Worden LJ, Rao SN. Syndromic diagnostic testing: a new way to approach patient care in the treatment of infectious diseases. J Antimicrob Chemother. 2021 Sep 23;76(Suppl 3):iii4-iii11. doi: 10.1093/jac/dkab245. PMID: 34555157; PMCID: PMC8460095.

How does syndromic testing contribute to cost savings in therapy for infectious diseases?

• By increasing the use of broad-spectrum antibiotics

• By prolonging hospital stays

• By promoting targeted treatment based on the specific pathogen

• By recommending unnecessary treatments

Answer explanation

Why is it important to distinguish between viral and bacterial infections in therapy?

• Viral infections are easier to treat with antibiotics.

• Both viral and bacterial infections require broad-spectrum antibiotics.

• To avoid unnecessary antibiotic use and reduce costs.

• To extend hospital stays for patients.

Answer explanation