Table of Contents
Photo Quiz
- Photo QuizAnswer to February 2020 Photo Quiz
Editorial
The Brief Case
Minireview
- MinireviewLaboratory Diagnosis of Sexually Transmitted Infections in Cases of Suspected Child Sexual Abuse
Laboratory diagnosis of microbial agents associated with sexually transmitted infections plays an important role in both the care of victims of child sexual abuse (CSA) and the investigation of suspected CSA incidents, with law enforcement implications. Rapid and sensitive test results prompt immediate actions to treat and protect the victimized children.
Bacteriology
- BacteriologyCutibacterium acnes Isolates from Deep Tissue Specimens Retrieved during Revision Shoulder Arthroplasty: Similar Colony Morphology Does Not Indicate Clonality
Cutibacterium acnes is the most common bacterium associated with periprosthetic shoulder infections. Sequencing of C. acnes has been proposed as a potential rapid diagnostic tool and a method of determining subtypes associated with pathogenicity and antibiotic resistance patterns. When multiple deep samples from the same surgery are culture positive for the...
- BacteriologyMulticenter Evaluation of the New Etest Gradient Diffusion Method for Piperacillin-Tazobactam Susceptibility Testing of Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter baumannii Complex
Piperacillin-tazobactam (P/T) is a β-lactam–β-lactamase inhibitor combination frequently used in the hospital setting. Etest is a gradient diffusion method that represents an alternative to broth microdilution (BMD) for performing antimicrobial susceptibility testing. We conducted a multicenter evaluation of the performance of the new P/T Etest compared to that of BMD following U.S.
- BacteriologyBrucella Exposure Risk Events in 10 Clinical Laboratories, New York City, USA, 2015 to 2017
From 2015 to 2017, 11 confirmed brucellosis cases were reported in New York City, leading to 10 Brucella exposure risk events (Brucella events) in 7 clinical laboratories (CLs). Most patients had traveled to countries where brucellosis is endemic and presented with histories and findings consistent with brucellosis.
- BacteriologyBlood-Modified Carbapenem Inactivation Method: a Phenotypic Method for Detecting Carbapenemase-Producing Enterobacteriaceae Directly from Positive Blood Culture Broths...
A variant of the modified carbapenem inactivation method (mCIM) was developed to detect carbapenemase activity directly from positive blood culture broths. The method, termed “Blood-mCIM,” was evaluated using Bactec blood culture bottles (Becton, Dickinson and Company, Franklin Lakes, NJ) inoculated with 27 different carbapenemase-producing Enterobacteriaceae (CPE) isolates and 34 different non-CPE isolates.
- BacteriologyClinical Evaluation of Three Commercial PCR Assays for the Detection of Macrolide Resistance in Mycoplasma genitalium
As macrolide resistance in Mycoplasma genitalium is increasing worldwide, macrolide resistance-associated mutations should be assessed in M. genitalium-positive specimens. New commercial kits are available for detection of macrolide resistance concurrently with...
- BacteriologyComparative Clinical Evaluation of NeoPlex RB-8 with Seeplex PneumoBacter ACE for Simultaneous Detection of Eight Respiratory Bacterial Pathogens
There are several convenient and accurate molecular assays to detect respiratory bacterial infection. The NeoPlex RB-8 detection kit (NeoPlex RB-8) is a new multiplex real-time PCR assay that simultaneously detects Streptococcus pneumoniae, Mycoplasma pneumoniae,...
- BacteriologyA Multicenter Study of the Revogene C. difficile System for Detection of the Toxin B Gene from Unformed Stool Specimens
Clostridioides difficile is the leading cause of diarrhea in hospitalized U.S. patients and results in over 400,000 cases of C. difficile infection per year. C. difficile infections have mortality rates of 6 to 30% and...
- BacteriologyEvaluation of Calcium-Enhanced Media for Colistin Susceptibility Testing by Gradient Agar Diffusion and Broth Microdilution...
Despite the increasing reliance on polymyxin antibiotics (polymyxin B and colistin) for treatment of multidrug-resistant Gram-negative infections, many clinical laboratories are unable to perform susceptibility testing due to the lack of accurate and reliable methods. Although gradient agar diffusion is commonly performed for other antimicrobials, its use for polymyxins is discouraged due to poor performance characteristics.
- BacteriologyActivity of Potential Alternative Treatment Agents for Stenotrophomonas maltophilia Isolates Nonsusceptible to Levofloxacin and/or Trimethoprim-Sulfamethoxazole
Stenotrophomonas maltophilia is difficult to treat due to the production of multiple intrinsic and acquired mechanisms of resistance. Trimethoprim-sulfamethoxazole (TMP-SMZ) and the fluoroquinolones have traditionally been considered the drugs of choice but are plagued by increasing resistance and adverse drug effects. The objective of this study was to evaluate the...
- BacteriologyHigh Agreement Between an Ultrasensitive Clostridioides difficile Toxin Assay and a C. difficile Laboratory Algorithm Utilizing GDH-and-Toxin Enzyme Immunoassays and Cytotoxin Testing
The Singulex Clarity C. diff toxins A/B (Clarity) assay is an automated, ultrasensitive immunoassay for the detection of Clostridioides difficile toxins in stool. In this study, the performance of the Clarity assay was compared to that of a multistep algorithm using an enzyme immunoassay (EIA) for detection of glutamate dehydrogenase (GDH) and toxins A and B...
- BacteriologyClinical Validation of the Aptima Bacterial Vaginosis and Aptima Candida/Trichomonas Vaginitis Assays: Results from a Prospective Multicenter Clinical Study
Infectious vaginitis due to bacterial vaginosis (BV), vulvovaginal candidiasis (VVC), and Trichomonas vaginalis accounts for a significant proportion of all gynecologic visits in the United States. A prospective multicenter clinical study was conducted to validate the performance of two new in vitro diagnostic transcription-mediated amplification nucleic acid...
Mycobacteriology and Aerobic Actinomycetes
- Mycobacteriology and Aerobic ActinomycetesCas12a/Guide RNA-Based Platform for Rapid and Accurate Identification of Major Mycobacterium Species
Mycobacterium tuberculosis infection and nontuberculous mycobacteria (NTM) infections exhibit similar clinical symptoms; however, the therapies for these two types of infections are different. Therefore, the rapid and accurate identification of M. tuberculosis and NTM species is very important for...
Parasitology
- ParasitologyIs Real-Time PCR Targeting Rep 529 Suitable for Diagnosis of Toxoplasmosis in Patients Infected with Non-Type II Strains in North America?
Toxoplasma gondii DNA detection is essential to antenatally diagnose a congenital infection and reactivation of a past infection in an immunocompromised patient. Initially, PCR methods targeted the 35-fold repetitive B1 gene, and more recently, coding sequence Rep 529 has been preferred, as it was reported to be repeated 200- to 300-fold and yielded far better...
- ParasitologyMulticentric Evaluation of the Bio-Evolution Toxoplasma gondii Assay for the Detection of Toxoplasma DNA in Immunocompromised Patients
PCR-based methods are a key tool for the diagnosis of toxoplasmosis in immunocompromised patients. Laboratory-developed protocols lack standardization. This study aimed to assess the performances of a commercial kit for the detection of Toxoplasma DNA in different specimens drawn from immunocompromised patients.
Virology
- VirologyOptimal Timing of Repeat Multiplex Molecular Testing for Respiratory Viruses
Determining whether and when multiplex nucleic acid amplification tests (NAATs) for respiratory viruses should be repeated is difficult. We analyzed 5 years of results for a multiplex NAAT targeting 14 respiratory viruses, to determine how often repeat tests were ordered and the time period in which results were likely to change. Results for NAATs performed on nasopharyngeal specimens and repeated within 90 days after initial testing...
- VirologyMolecular Detection of Feline Leukemia Virus in Oral, Conjunctival, and Rectal Mucosae Provides Results Comparable to Detection in Blood
Feline leukemia virus (FeLV) infection causes immunosuppression, degeneration of the hematopoietic system, and fatal neoplasms. FeLV transmission occurs mainly by close social contact of infected and susceptible cats. Developing procedures for the diagnosis of feline retroviruses is crucial to reduce negative impacts on cat health and increase the number of animals tested. Blood collection requires physical or chemical restraint and is...
- VirologyDiagnostic Value of Detection of Pregenomic RNA in Sera of Hepatitis B Virus-Infected Patients with Different Clinical Outcomes
Pregenomic RNA (pgRNA) is a direct transcription product of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA), and it plays important roles in viral genome amplification and replication. This study was designed to investigate whether serum pgRNA is a strong alternative marker for reflecting HBV cccDNA levels and to analyze the correlation between serum pgRNA, serum HBV DNA, and hepatitis B surface antigen (HBsAg).
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Immunoassays
- ImmunoassaysComparison of Different Commercially Available Enzyme-Linked Immunosorbent Assays with Immunofluorescence Test for Detection of Phase II IgG and IgM Antibodies to Coxiella burnetii
Several commercially available enzyme-linked immunosorbent assays (ELISAs) for the detection of phase II IgG or IgM antibodies against Coxiella burnetii were compared. In addition, an indirect immunofluorescence test was used as a confirmation test. In all, 70 serum samples for IgG and 43 serum samples for IgM were tested. The ELISAs showed large differences in...
- ImmunoassaysEstablishment of a Highly Sensitive Assay for Detection of Hepatitis E Virus-Specific Immunoglobulins
Hepatitis E, a liver disease caused by infection with the hepatitis E virus (HEV), is a worldwide emerging disease. The diagnosis is based on the detection of viral RNA and of HEV-specific immunoglobulins (Ig). For the latter, various assays are commercially available but still lack harmonization. In this study, a Luminex-based multiplex serological assay was established that measures the presence of total IgG, IgA, and IgM antibodies,...
- ImmunoassaysClinical Significance of Low Serum Cryptococcal Antigen Titers by Lateral Flow Assay in Immunocompromised Patients: a Retrospective Case-Control Study
Cryptococcus species are associated with invasive fungal infections in immunosuppressed individuals. The clinical significance of low-titer cryptococcal antigen (CrAg) by lateral flow assay is frequently uncertain. We investigated the correlation of low CrAg titers with disease in an immunocompromised patient population. Patients with first-time positive CrAg results with low serum titers (≤1:10) at two medical centers (Los...
Epidemiology
- EpidemiologyClinical and Analytical Performance of the BD Onclarity HPV Assay with SurePath Screening Samples from the Danish Cervical Screening Program Using the VALGENT Framework
The Validation of HPV Genotyping Tests (VALGENT) framework is an international cooperation designed to evaluate human papillomavirus (HPV) assays with genotyping capabilities.
- EpidemiologyWhole-Genome Sequencing of Corynebacterium diphtheriae Isolates Recovered from an Inner-City Population Demonstrates the Predominance of a Single Molecular Strain
In some parts of the world, Corynebacterium diphtheriae has reemerged as a pathogen, especially as a cause of infections among impoverished and marginalized populations. We performed whole-genome sequencing (WGS) on all cutaneous C. diphtheriae isolates (n = 56) from Vancouver’s inner-city...
Commentaries
In this issue of the Journal of Clinical Microbiology, R. E. Bumgarner, D. Harrison, and J. E. Hsu (J Clin Microbiol 58:e00121-19, 2020, https://doi.org/10.1128/JCM.00121-19) address in a retrospective analysis that clonality of Cutibacterium acnes isolates from deep tissue specimens obtained from patients...
In this issue of the Journal of Clinical Microbiology, S. García-Fernandez, Y. Bala, T. Armstrong, M. Garcia-Castillo, et al. (J Clin Microbiol 58:e01042-19, 2020, https://doi.org/10.1128/JCM.01042-19) describe the performance of a reformulated Etest for piperacillin-tazobactam.