The need for fast and accurate detection of dermatomycosis.

Dermatomycosis of the hair, skin, or nails is one of the most common fungal infections worldwide. Beyond permanent damage to the affected area, the risk of severe dermatomycosis in immunocompromised people can be life-threatening. The potential risk of delayed or improper treatment highlights the need for a rapid and accurate diagnosis. However, with traditional methods of fungal diagnostics such as culture, a diagnosis can take several weeks. Alternative diagnostic technologies have been developed which allow for an appropriate and timely selection of an antifungal treatment, preventing nonspecific over-the-counter self-medication. Such techniques include molecular methods, such as polymerase chain reaction (PCR), real-time PCR, DNA microarray, next-generation sequencing, in addition to matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Molecular methods can help close the 'diagnostic gap' observed with traditional cultures and microscopy and allow for a rapid detection of dermatomycosis with increased sensitivity and specificity. In this review, advantages and disadvantages of traditional and molecular techniques are discussed, in addition to the importance of species-specific dermatophyte determination. Finally, we highlight the need for clinicians to adapt molecular techniques for the rapid and reliable detection of dermatomycosis infections and to reduce adverse events.

Dermatomycosis is one of the most common fungal infections worldwide. Traditional fungal diagnostics are limited and can take several weeks. Molecular techniques can detect dermatomycosis pathogens quickly and allow for species-specific identification which is important for treatment.

Phosphorylated neurofilament heavy chain: a potential diagnostic biomarker in amyotrophic lateral sclerosis.

Neuroaxonal damage is a feature of various neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Phosphorylated neurofilament heavy chain (pNfH) is a cytoskeletal structural protein released as a result of axonal damage into the cerebrospinal fluid (CSF), and subsequently into the blood. Due to high specificity for neuronal cell damage, pNfH is advantageous over other biomarkers, for ALS disease identification. Here, we review the structure and function of neurofilaments and their role in detection of various neurodegenerative conditions. In addition, a retrospective meta-analysis was performed to depict the significance of pNfH as a valuable diagnostic and prognostic biomarker in ALS.

Heme inhibits the activity of a c-di-GMP phosphodiesterase in Vibrio cholerae.

Heme, a complex of iron and protoporphyrin IX, plays an essential role in numerous biological processes including oxygen transport, oxygen storage, and electron transfer. The role of heme as a prosthetic group in bacterial hemoprotein gas sensors, which utilize heme as a cofactor for the binding of diatomic gas molecules, has been well studied. Less well known is the role of protein sensors of heme. In this report, we characterize the heme binding properties of a phosphodiesterase, CdpA, from Vibrio cholerae. We demonstrate that the N-terminal domain of CdpA is a NosP domain capable of heme binding, which consequently inhibits the c-di-GMP hydrolysis activity of the C-terminal phosphodiesterase domain. Further evidence for CdpA as a heme responsive sensor is supported by a relatively fast rate of heme dissociation. This study provides insight into an emerging class of heme-responsive sensor proteins.

Serological Biomarkers and Their Detection in Autoimmune Bullous Skin Diseases.

Autoimmune bullous diseases (AIBDs) are a group of skin-related disorders that involve damage to structures maintaining cell-cell adhesion, such as desmosomes and hemidesmosomes. Key AIBDs include pemphigus related diseases, pemphigoid related conditions, acquired epidermolysis bullosa (EBA), and dermatitis herpetiformis (DH). Each group of conditions exhibits characteristic clinical lesion patterns and is associated with specific autoantibodies targeting epidermal and dermal structures involved in cell-cell adhesion and skin integrity. Pemphigus diseases primarily target desmoglein (Dsg) 3 and Dsg1 proteins but several non-Dsg autoantibodies have also been linked to pemphigus. Pemphigoid diseases typically target bullous pemphigoid (BP)180 and BP230; EBA is associated with antibodies directed against anti-type VII collagen and DH by IgA autoantibodies against tissue transglutaminase and deaminated gliadin. Investigation into the serological biomarkers found in AIBDs have allowed the development of diagnostic assessments (i.e. tissue antibody detection and serological testing) based on the unique autoantibody profiles of a particular disease group. The methods for the detection and quantification of disease-associated autoantibodies continue to evolve and improve.

COVID-19: Testing Landscape Post-Infection, -Vaccination, and Future Perspectives.

On March 11, 2020, the World Health Organization declared the coronavirus disease 2019 (COVID-19) outbreak a global pandemic. Although molecular testing remains the gold standard for COVID-19 diagnosis, serological testing enables the evaluation of the immune response to severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection and vaccination, and can be used to assess community viral spread. This review summarizes and analyzes the current landscape of SARS-CoV-2 testing in the United States and includes guidance on both when and why it is important to use direct pathogen detection and/or serological testing. The usefulness of monitoring humoral and cellular immune responses in infected and vaccinated patients is also addressed. Finally, this review considers current challenges, future perspectives for SARS-CoV-2 testing, and how diagnostics are being adapted as the virus evolves.

Self-Patterned Nanoscale Topography of Thin Copolymer Films Prepared by Evaporative Assembly-Resist Early-Stage Bacterial Adhesion.

Biofilm formation on the surfaces of indwelling medical devices has become a growing health threat due to the development of antimicrobial resistance to infection-causing bacteria. For example, ventilator-associated pneumonia caused by Pseudomonas and Staphylococci species has become a significant concern in treatment of patients during COVID-19 pandemic. Nanostructured surfaces with antifouling activity are of interest as a promising strategy to prevent bacterial adhesion without triggering drug resistance. In this study, we report a facile evaporative approach to prepare block copolymer film coatings with nanoscale topography that resist bacterial adhesion. The initial attachment of the target bacterium Pseudomonas aeruginosa PAO1 to copolymer films as well as homopolymer films was evaluated by fluorescence microscopy. Significant reduction in bacterial adhesion (93-99% less) and area coverage (>92% less) on the copolymer films was observed compared with that on the control and homopolymer films [poly(methacrylic acid) (PMAA)─only 40 and 23% less, respectively]. The surfaces of poly(styrene)-PMAA copolymer films with patterned nanoscale topography that contains sharp peaks ranging from 20 to 80 nm spaced at 30-50 nm were confirmed by atomic force microscopy and the corresponding surface morphology analysis. Investigation of the surface wettability and surface potential of polymer films assists in understanding the effect of surface properties on the bacterial attachment. Comparison of bacterial growth studies in polymer solutions with the growth studies on coatings highlights the importance of physical nanostructure in resisting bacterial adhesion, as opposed to chemical characteristics of the copolymers. Such self-patterned antifouling surface coatings, produced with a straightforward and energy-efficient approach, could provide a convenient and effective method to resist bacterial fouling on the surface of medical devices and reduce device-associated infections.

SDS-PAGE and Dot Blot Autoradiography: Tools for Quantifying Histidine Kinase Autophosphorylation.

Histidine kinases play a vital role in bacterial signal transduction. However, methods for studying the activity of histidine kinases in vitro are limited in comparison to those for investigating serine, threonine, and tyrosine kinases, largely due to the lability of the phosphoramidate (P-N) bond. Here, we describe two useful methods for quantifying histidine kinase autophosphorylation: SDS-PAGE autoradiography and dot blot autoradiography/scintillation counting.

Insights Into Nitric Oxide Modulated Quorum Sensing Pathways.

The emerging threat of drug resistant bacteria has prompted the investigation into bacterial signaling pathways responsible for pathogenesis. One such mechanism by which bacteria regulate their physiology during infection of a host is through a process known as quorum sensing (QS). Bacteria use QS to regulate community-wide gene expression in response to changes in population density. In order to sense these changes in population density, bacteria produce, secrete and detect small molecules called autoinducers. The most common signals detected by Gram-negative and Gram-positive bacteria are acylated homoserine lactones and autoinducing peptides (AIPs), respectively. However, increasing evidence has supported a role for the small molecule nitric oxide (NO) in influencing QS-mediated group behaviors like bioluminescence, biofilm production, and virulence. In this review, we discuss three bacteria that have an established role for NO in influencing bacterial physiology through QS circuits. In two Vibrio species, NO has been shown to affect QS pathways upon coordination of hemoprotein sensors. Further, NO has been demonstrated to serve a protective role against staphylococcal pneumonia through S-nitrosylation of a QS regulator of virulence.

Discovery of a Nitric Oxide Responsive Quorum Sensing Circuit in Vibrio cholerae.

Group behavior of the human pathogen Vibrio cholerae, including biofilm formation and virulence factor secretion, is mediated by a process known as quorum sensing. Quorum sensing is a way by which bacteria coordinate gene expression in response to population density through the production, secretion, and detection of small molecules called autoinducers. Four autoinducer-mediated receptor histidine kinases have been implicated in quorum sensing through the phosphotransfer protein LuxU: CqsS, LuxP/Q, CqsR, and VpsS (Vc1445). Of these receptor kinases, VpsS is predicted to be cytosolic, and its cognate autoinducer is currently unknown. In this study, we demonstrate that the nitric oxide-bound complex of a member of the recently discovered family of nitric oxide-responsive hemoproteins called NosP (VcNosP is encoded by Vc1444; this gene product is also known as VpsV) inhibits the autophosphorylation activity of VpsS and thus phosphate flow to LuxU. Therefore, we propose that VpsS contributes to the regulation of quorum sensing in a nitric-oxide-dependent manner through its interaction with NosP.