Repeat testing of mpox specimens with late CTs improves detection of potential false positive cases.

The mpox pandemic necessitated the rapid development of clinical assays for monkeypox virus detection. While the majority of mpox specimens have high viral loads with corresponding early cycle threshold (CT) values, reports have indicated some specimens with late CT values can represent false positive results. To mitigate this risk, the Centers for Disease Control and Prevention (CDC) published an advisory recommending repeat testing of all specimens with CT values ≥34.

Development and validation of a next-generation sequencing assay with open-access analysis software for detecting resistance-associated mutations in CMV.

Cytomegalovirus (CMV) resistance testing by targeted next-generation sequencing (NGS) allows for the simultaneous analysis of multiple genes. We developed and validated an amplicon-based Ion Torrent NGS assay to detect CMV resistance mutations in UL27, UL54, UL56, and UL97 and compared the results to standard Sanger sequencing. NGS primers were designed to generate 83 overlapping amplicons of four CMV genes (~10 kb encompassing 138 mutation sites).

HIV-1 Drug Resistance Assay Using Ion Torrent Next Generation Sequencing and On-Instrument End-to-End Analysis Software.

HIV-1 antiretroviral therapy management requires sequencing the protease, reverse transcriptase, and integrase portions of the HIV-1 gene. Most resistance testing is performed with Sanger sequencing, which has limited ability to detect minor variants. Next generation sequencing (NGS) platforms enable variant detection at frequencies as low as 1% allowing for earlier detection of resistance and modification of therapy.

Respiratory Viral Detection in Children and Adults: Comparing Asymptomatic Controls and Patients With Community-Acquired Pneumonia.

Background: The clinical significance of viruses detected in patients with community-acquired pneumonia (CAP) is often unclear.

Methods: We conducted a prospective study to identify the prevalence of 13 viruses in the upper respiratory tract of patients with CAP and concurrently enrolled asymptomatic controls with real-time reverse-transcriptase polymerase chain reaction. We compared age-stratified prevalence of each virus between patients with CAP and controls and used multivariable logistic regression to calculate attributable fractions (AFs).

Evaluation of the FilmArray® Respiratory Panel for clinical use in a large children's hospital.

Background: Respiratory pathogens are a leading cause of hospital admission and traditional detection methods are time consuming and insensitive. Multiplex molecular detection methods have recently been investigated in hope of replacing these traditional techniques with rapid panel-based testing.

Objectives: This study evaluated the FilmArray(®) Respiratory Panel ([FARP], Idaho Technology Inc.

A novel capillary electrophoresis-based multiplex PCR assay for detection of respiratory pathogens.

The field of infectious disease testing has recently experienced rapid expansion in the number of multiplexed PCR-based assays available for detecting respiratory pathogens. This study provides a preliminary evaluation of a multiplex assay from Seegene that uses capillary electrophoresis as the detection platform for viral and bacterial respiratory pathogens. We compared this technology to a real-time PCR assay for 3 viral targets.

Identifying respiratory viruses in nasal mucus from children.

Large amounts of respiratory viruses are shed in nasal secretions by children. Nasal mucus was compared with nasopharyngeal swabs as a source for respiratory virus testing. Multiplex reverse transcription-polymerase chain reaction detected virus in nasal mucus specimens in 73% (11/15) of positive cases, demonstrating the potential utility of less invasive specimens when a highly sensitive method is used for respiratory virus detection.

Limited utility of culture for Mycoplasma pneumoniae and Chlamydophila pneumoniae for diagnosis of respiratory tract infections.

We assessed the utility of culture for Mycoplasma pneumoniae and Chlamydophila pneumoniae to diagnose respiratory tract infections. Compared to PCR and IgM serology, culture was less sensitive and had extremely low yield. Culture is not recommended for these pathogens, and this method should be eliminated from routine practice.

Performance of diagnostic tests to detect respiratory viruses in older adults.

The performance of 4 laboratory methods for diagnosis of viral respiratory tract infections (RTI) in older adults was evaluated. Seventy-four nasopharyngeal (NP) swab specimens were obtained from 60 patients with RTI at a long-term care facility over 2 respiratory seasons. Sixteen specimens were positive for a respiratory virus by at least 1 method.

Development of a multiplex real-time RT-PCR assay for detection of influenza A, influenza B, RSV and typing of the 2009-H1N1 influenza virus.

A high-throughput real-time RT-PCR assay was developed to amplify and detect a conserved region of the hemagglutinin gene of the 2009-H1N1 influenza A virus using a minor groove binder-conjugated hybridization probe. The assay was paired with a separate triplex real-time assay that detects influenza A via the matrix gene, influenza B and RSV in a multiplex format and compared with the Centers for Disease Control and Prevention (CDC) rRT-PCR assay using 143 samples. The 2009-H1N1 portion of the multiplex assay had 100% correlation with the CDC assay, while the triplex assay had a 99% agreement.

Performance of enterovirus genotyping targeting the VP1 and VP2 regions on non-typeable isolates and patient specimens.

Culture and serotyping of human enteroviruses are time-consuming and labor-intensive. Targeted nucleic acid sequencing has emerged as a powerful alternative to conventional methods. Many published genotyping assays use two-step reverse transcription and polymerase chain reaction (RT-PCR), nested PCR protocols, and/or reflexive testing algorithms.

Evaluation of Nanogen MGB Alert Detection Reagents in a multiplex real-time PCR for influenza virus types A and B and respiratory syncytial virus.

A multiplex real-time RT-PCR assay that detects influenza A, influenza B and respiratory syncytial virus (RSV) using the MGB Alert Influenza A&B/RSV Detection Reagent RUO (Nanogen, San Diego, CA) was developed. The Nanogen detection reagents consist of PCR primers and minor groove binder-conjugated hybridization probes for each virus and an internal control. Virus typing was determined by post-PCR melt curve analysis.

Description and validation of a novel real-time RT-PCR enterovirus assay.

Background: Enteroviruses are a leading cause of aseptic meningitis in adult and pediatric populations. We describe the development of a real-time RT-PCR assay that amplifies a small target in the 5' nontranslated region upstream of the classical Rotbart enterovirus amplicon. The assay includes an RNA internal control and incorporates modified nucleotide chemistry.

Description of a multiplex Bordetella pertussis and Bordetella parapertussis LightCycler PCR assay with inhibition control.

While culture for Bordetella species is highly specific, sensitivity is extremely variable due to patient age, immunization status, antibiotic treatment, and specimen transport conditions. We evaluated a real-time multiplex PCR assay as an alternative to culture for the detection and differentiation of Bordetella pertussis and Bordetella parapertussis. The PCR conditions allowed the simultaneous detection of one B.

Ultrasonic enhancement of antibiotic action on several species of bacteria.

The effect of the antibiotics gentamicin, streptomycin, kanamycin, tetracycline, and ampicillin on planktonic cultures of Enterobacter aerogenes, Serratia marcescens, Salmonella derby, Streptococcus mitis, and Staphylococcus epidermidis with and without an application of 70 kHz ultrasound was studied. The ultrasound was applied at levels that had no inhibitory effect on planktonic cultures of bacteria. Measurements of viability at, above, and below the minimum inhibitory concentration of the above antibiotics on the planktonic cultures of these bacteria showed that a simultaneous application of 70 kHz ultrasound and antibiotic significantly increased the effectiveness of selected antibiotics.