Table of Contents
Photo Quiz
Photo QuizPhoto Quiz: An Unusual Knee Infection
Photo QuizAnswer to April 2019 Photo Quiz
Editorial
The Brief Case
Minireviews
MinireviewToward the Development of a Circulating Free DNA-Based In Vitro Diagnostic Test for Infectious Diseases: a Review of Evidence for TuberculosisThe detection of circulating free DNA (cfDNA) has transformed the field of oncology and prenatal diagnostics. Clinical application of cfDNA for disease diagnosis and monitoring, however, is relatively recent in the field of infectious disease.
MinireviewCRISPR-Cas Biology and Its Application to Infectious DiseasesInfectious diseases remain a global threat contributing to excess morbidity and death annually, with the persistent potential for destabilizing pandemics. Improved understanding of the pathogenesis of bacteria, viruses, fungi, and parasites, along with rapid diagnosis and treatment of human infections, is essential for improving infectious disease outcomes worldwide.
MinireviewAntimicrobial Susceptibility Testing for Polymyxins: Challenges, Issues, and RecommendationsPolymyxins, including polymyxin B and polymyxin E (colistin), are now increasingly being used worldwide to treat patients with multidrug-resistant (MDR) Gram-negative bacterial infections. This necessitates that laboratories employ an accurate and reliable method for the routine performance of polymyxin susceptibility testing.
Bacteriology
BacteriologyImproved Performance of a Rapid Immunochromatographic Assay for Detection of PBP2a in Non-Staphylococcus aureus Staphylococcal SpeciesNon-Staphylococcus aureus staphylococcal species (non-SASS) are important pathogens in both animal and human populations. The development of β-lactam resistance in non-SASS through acquisition and expression of penicillin-binding protein 2a (PBP2a) represents a significant clinical and public health threat.
BacteriologyEvaluation of Shigella Species Azithromycin CLSI Epidemiological Cutoff Values and Macrolide Resistance GenesAzithromycin (AZM) has been recommended by the American Academy of Pediatrics for the treatment of shigellosis in children. In this study, 502 Shigella species isolated between 2004 and 2014 were tested for AZM epidemiological cutoff values (ECV) by disk diffusion.
BacteriologyPCR-Based Method for Shigella flexneri Serotyping: International Multicenter ValidationShigella spp. are a leading cause of human diarrheal disease worldwide, with Shigella flexneri being the most frequently isolated species in developing countries.
BacteriologyA Real-Time Multiplex PCR Assay for Detection of Elizabethkingia Species and Differentiation between Elizabethkingia anophelis and E. meningosepticaNosocomial infections of Elizabethkingia species can have fatal outcomes if not identified and treated properly. The current diagnostic tools available require culture and isolation, which can extend the reporting time and delay treatment.
BacteriologyDirect Identification of Pathogens in Urine by Use of a Specific Matrix-Assisted Laser Desorption Ionization–Time of Flight Spectrum DatabaseUrinary tract infections are among the most common reasons for antimicrobial treatment, and early diagnosis could have a significant impact by enabling rapid administration of the adapted antibiotic and preventing complications. The current delay between sample receipt and pathogen identification is about 24 to 48 h, which could be significantly shortened by use of an accurate direct method.
BacteriologyVirulence-Related Genes and Coenteropathogens Associated with Clinical Outcomes of Enteropathogenic Escherichia coli Infections in Children from the Brazilian Semiarid Region: a Case-Control Study of Diarrhea...Enteropathogenic Escherichia coli (EPEC) is a major cause of diarrhea in children from developing countries and presents high genetic variability. We aimed to characterize the EPEC virulence-related gene (VRG) distribution and copathogens associated with diarrhea and nutrition-related outcomes in children from the low-income Brazilian semiarid region.
BacteriologyEvaluation of the Performance of the Cobas CT/NG Test for Use on the Cobas 6800/8800 Systems for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in Male and Female Urogenital SamplesThe clinical performance of the Cobas CT/NG assay on the Cobas 6800/8800 systems (Cobas) for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae was established in a multisite, prospective collection study using male and female urogenital specimens; supportive data from archived...
BacteriologyStreptococcus agalactiae Strains with Chromosomal Deletions Evade Detection with Molecular MethodsSurveillance of circulating microbial populations is critical for monitoring the performance of a molecular diagnostic test. In this study, we characterized 31 isolates of Streptococcus agalactiae (group B Streptococcus [GBS]) from several geographic locations in the United States and Ireland that contain deletions in or adjacent to the region of the...
Mycobacteriology and Aerobic Actinomycetes
Mycobacteriology and Aerobic ActinomycetesRetrospective Analysis of False-Positive and Disputed Rifampin Resistance Xpert MTB/RIF Assay Results in Clinical Samples from a Referral Hospital in Hunan, ChinaConcerns about the specificity of the Xpert MTB/RIF (Xpert) assay have arisen, as false-positive errors in the determination of Mycobacterium tuberculosis complex (MTBC) infection and rifampin (RIF) resistance in clinical practice have been reported. Here, we investigated 33 cases where patients were determined to be RIF susceptible using the Bactec MGIT 960 (MGIT)...
Mycobacteriology and Aerobic ActinomycetesImplementation of Semiautomated Antimicrobial Susceptibility Interpretation Hardware for Nontuberculous Mycobacteria May Overestimate Susceptibility...Nontuberculous mycobacteria (NTM) cause severe opportunistic infections and have a rising incidence in most settings. Rising diagnostic need must be met by national reference laboratories, which rely on Clinical and Laboratory Standards Institute (CLSI) guideline-approved manual readout of microtiter plates for antimicrobial susceptibility testing (AST) to determine antibiotic minimum inhibitory concentrations (MICs).
Mycobacteriology and Aerobic ActinomycetesHeat Inactivation Renders Sputum Safe and Preserves Mycobacterium tuberculosis RNA for Downstream Molecular TestsThe World Health Organization End Tuberculosis (TB) strategy has called for the development of—and increased access to—effective tools for diagnosis and treatment of TB disease. Mycobacterium tuberculosis , the causative agent of TB, is categorized as a highly infectious agent.
Mycology
MycologyCandida auris Clinical Isolates from South Korea: Identification, Antifungal Susceptibility, and GenotypingCandida auris is an emerging worldwide fungal pathogen. Over the past 20 years, 61 patient isolates of C. auris (4 blood and 57 ear) have been obtained from 13 hospitals in Korea.
MycologyFluorescent Capillary Electrophoresis Is Superior to Culture in Detecting Candida Species from Samples of Urinary Catheters and Ureteral Stents with Mono- or Polyfungal Biofilm GrowthMolecular techniques in fungal detection and identification represent an efficient complementary diagnostic tool which is increasingly used to overcome limitations of routinely used culture techniques. The aim of this study was to characterize Candida sp.
MycologyDiagnosing Invasive Pulmonary Aspergillosis in Hematology Patients: a Retrospective Multicenter Evaluation of a Novel Lateral Flow DeviceInvasive pulmonary aspergillosis (IPA) is a potentially lethal infection in patients with hematological diseases or following allogeneic stem cell transplantation. Early diagnosis is essential, as delayed treatment results in increased mortality.
Parasitology
ParasitologyComparison of Loop-Mediated Isothermal Amplification and Real-Time PCR Assays for Detection of Strongyloides Larvae in Different Specimen MatricesStrongyloides stercoralis can cause disease that ranges from asymptomatic chronic infection to fatal hyperinfection. Diagnosis from stool can be challenging because the most sensitive conventional tests require live larvae to be effective and there can be low larval output in chronic infection.
Virology
VirologyEvaluation of the Aptima HCV Quant Dx Assay Using Serum and Dried Blood SpotsHepatitis C virus (HCV) RNA quantitation is the primary method by which active HCV infections are identified and the response to direct-acting antiviral therapy is monitored. This study describes the evaluation of the Aptima HCV Quant Dx assay (Aptima HCV) performed on the Panther system.
VirologySeparation of Plasma from Whole Blood by Use of the cobas Plasma Separation Card: a Compelling Alternative to Dried Blood Spots for Quantification of HIV-1 Viral LoadPlasma HIV viral load testing is the preferred means of monitoring antiretroviral treatment response. Dried blood spots (DBSs) hold considerable logistical advantages over EDTA samples, but they more frequently misclassify virological failure and have higher limits of detection (LoD).
VirologyImpact of Rapid Molecular Diagnostic Testing of Respiratory Viruses on Outcomes of Adults Hospitalized with Respiratory Illness: a Multicenter Quasi-experimental StudyA standard multiplex PCR offers comprehensive testing for respiratory viruses. However, it has traditionally been performed in a referral laboratory with a lengthy turnaround time, which can reduce patient flow through the hospital.
VirologySimultaneous Detection and Differentiation between Wild-Type and Vaccine Measles Viruses by a Multiplex Real-Time Reverse Transcription-PCR AssayMeasles is one of the most contagious viral respiratory infections and was declared to be eliminated from Canada in 1998; however, measles cases and outbreaks still occur every year through reintroduction from other parts of the world. Laboratory confirmation of measles virus (MV) RNA by real-time PCR provides a definitive diagnosis, and molecular analysis to determine the genotype is the only way to distinguish between wild-type and...
VirologyIn Vitro Susceptibility of Hepatitis C Virus Genotype 1 through 6 Clinical Isolates to the Pangenotypic NS3/4A Inhibitor VoxilaprevirVoxilaprevir is a direct-acting antiviral agent (DAA) that targets the NS3/4A protease of hepatitis C virus (HCV). High sequence diversity of HCV and inadequate drug exposure during unsuccessful treatment may lead to the accumulation of variants with reduced susceptibility to DAAs, including NS3/4A protease inhibitors such as voxilaprevir.
VirologyDevelopment of a Standardized Sanger-Based Method for Partial Sequencing and Genotyping of Dengue VirusesThe global expansion of dengue viruses (DENV-1 to DENV-4) has contributed to the divergence, transmission, and establishment of genetic lineages of epidemiological concern; however, tracking the phylogenetic relationships of these virus is not always possible due to the inability of standardized sequencing procedures in resource-limited public health laboratories. Consequently, public genomic data banks contain inadequate representation...
Immunoassays
ImmunoassaysPerformance of a Novel Low-Cost, Instrument-Free Plasma Separation Device for HIV Viral Load Quantification and Determination of Treatment Failure in People Living with HIV in Malaysia: a Diagnostic Accuracy StudyHIV viral load (VL) testing is the recommended method for monitoring the response of people living with HIV and receiving antiretroviral therapy (ART). The availability of standard plasma VL testing in low- and middle-income countries (LMICs), and access to this testing, are limited by the need to use fresh plasma.
Epidemiology
EpidemiologyEpidemiological Typing of Serratia marcescens Isolates by Whole-Genome Multilocus Sequence TypingSerratia marcescens is an opportunistic bacterial pathogen. It is notorious for its increasing antimicrobial resistance and its potential to cause outbreaks of colonization and infections, predominantly in neonatal intensive care units (NICUs).
EpidemiologyVaccination of Icelandic Children with the 10-Valent Pneumococcal Vaccine Leads to a Significant Herd Effect among Adults in IcelandThe introduction of pneumococcal conjugate vaccines (PCVs) into childhood vaccination programs has reduced carriage of vaccine serotypes and pneumococcal disease. The 10-valent PCV was introduced in Iceland in 2011.
Author Correction
Masthead
Commentaries
The emerging yeast Candida auris can be highly drug resistant, causing invasive infections, and large outbreaks. C. auris went from an unknown pathogen a decade ago to being reported in over thirty countries on six continents.
To determine if rapid molecular testing for respiratory viruses in patients with respiratory illnesses can provide advantages to patients and hospitals, rigorous investigations on the impacts of using these assays are required. Well-conducted studies are needed to inform decisions about implementation of new rapid assays to replace standard molecular testing or to initiate testing in laboratories that are currently not doing molecular...