Sterilization of gowns: making the most of a scarce commodity during the COVID-19 pandemic.

Baylor Clinic in Mbabane, Eswatini, convened a crisis meeting to tackle critical shortages of long-sleeved disposable gowns that resulted from COVID-19 pandemic constraints on available personal protective equipment (PPE). A strategy deemed safe, affordable and sustainable was adopted to autoclave and re-use gowns based on a risk-stratified approach. Key objectives were to ensure essential infection control and prevention (ICP) for medical doctors, nurses, and laboratory teams. Administrative, environmental and personal protective measures for ICP were enhanced through regular staff training. This strategy for gown re-use has been invaluable in motivating responsible stewardship and maximization of available gowns during the COVID-19 pandemic.

La Baylor Clinic de Mbabane, Eswatini, a convoqué une réunion de crise pour remédier à la grave pénurie de blouses jetables à manches longues due au manque d'équipements de protection individuelle (PPE) lié à la pandémie de COVID-19. Une stratégie jugée sûre, abordable et durable a été adoptée pour stériliser par autoclave et réutiliser les blouses en prenant appui sur une approche stratifiée des risques. Les objectifs clés étaient de garantir la prévention et le contrôle des infections (ICP) pour les médecins, les infirmiers et les équipes de laboratoire. Les mesures ICP d'ordre administratif, environnemental et de protection individuelle ont été renforcées par le biais de formations régulières du personnel. Cette stratégie de réutilisation des blouses a permis de promouvoir une gestion responsable et de tirer au maximum profit des blouses disponibles pendant la pandémie de COVID-19.

Laboratory comparison of stool processing methods for Xpert® Ultra.

TB disease diagnosis in children is difficult due to non-specific symptoms, paucibacillary disease and the need for invasive procedures to obtain diagnostic specimens. In many settings, these specimens are simply not collected and therefore stool, easily obtained, has emerged as a promising specimen for the diagnosis of child TB. In this study, stool from a healthy adult was spiked with known concentrations of bacille Calmette-Guérin vaccine and tested using the Xpert® Ultra assay to determine the relative detection and error rate associated with four different published stool processing methods.

Le diagnostic de TB maladie chez l'enfant est difficile en raison de la non spécificité de symptômes, de son caractère paucibacillaire et du besoin de procédures invasives pour obtenir des échantillons diagnostiques. Dans de nombreux contextes, ces échantillons ne sont tout simplement pas recueillis ; c'est pourquoi les selles, faciles à obtenir, sont apparus comme un échantillon prometteur pour le diagnostic de la TB de l'enfant. Dans cette étude, des selles d'un adulte en bonne santé ont été enrichies avec des concentrations connues de vaccin Bacille Calmette-Guérin et testés avec le test Xpert Ultra pour déterminer les taux relatifs de détection et d'erreur associés à quatre différentes méthodes publiées de traitement des selles.

Perspectives for personalized therapy for patients with multidrug-resistant tuberculosis.

According to the World Health Organization (WHO), tuberculosis is the leading cause of death attributed to a single microbial pathogen worldwide. In addition to the large number of patients affected by tuberculosis, the emergence of Mycobacterium tuberculosis drug-resistance is complicating tuberculosis control in many high-burden countries. During the past 5 years, the global number of patients identified with multidrug-resistant tuberculosis (MDR-TB), defined as bacillary resistance at least against rifampicin and isoniazid, the two most active drugs in a treatment regimen, has increased by more than 20% annually. Today we experience a historical peak in the number of patients affected by MDR-TB. The management of MDR-TB is characterized by delayed diagnosis, uncertainty of the extent of bacillary drug-resistance, imprecise standardized drug regimens and dosages, very long duration of therapy and high frequency of adverse events which all translate into a poor prognosis for many of the affected patients. Major scientific and technological advances in recent years provide new perspectives through treatment regimens tailor-made to individual needs. Where available, such personalized treatment has major implications on the treatment outcomes of patients with MDR-TB. The challenge now is to bring these adances to those patients that need them most.

Point of care diagnostics for tuberculosis.

The goals of the End TB strategy, which aims to achieve a 90% reduction in tuberculosis (TB) incidence and a 95% reduction in TB mortality by 2035, will not be achieved without new tools to fight TB. These include improved point of care (POC) diagnostic tests that are meant to be delivered at the most decentralised levels of care where the patients make the initial contact with the health system, as well as within the community. These tests should be able to be performed on an easily accessible sample and provide results in a timely manner, allowing a quick treatment turnaround time of a few minutes or hours (in a single clinical encounter), hence avoiding patient loss-to-follow-up. There have been exciting developments in recent years, including the WHO endorsement of Xpert MTB/RIF, Xpert MTB/RIF Ultra, loop-mediated isothermal amplification (TB-LAMP) and lateral flow lipoarabinomannan (LAM). However, these tests have limitations that must be overcome before they can be optimally applied at the POC. Furthermore, worrying short- to medium-term gaps exist in the POC diagnostic test development pipeline. Thus, not only is better implementation of existing tools and algorithms needed, but new research is required to develop new POC tests that allow the TB community to truly make an impact and find the "missed TB cases".

Non-invasive diagnosis of pink basal cell carcinoma: how much can we rely on dermoscopy and reflectance confocal microscopy?

BACKGROUND: Non-pigmented 'pink' cutaneous lesions in differential diagnosis with basal cell carcinoma may present a challenge for clinicians. Our objective was to determine the potential improvement of diagnostic accuracy using combined dermoscopy-reflectance confocal microscopy (RCM) image evaluation. METHODS: Two hundred and sixty clinically equivocal 'pink' cutaneous lesions were evaluated retrospectively. Reader accuracy was tested with dermoscopy images only vs. RCM and combined dermoscopy-RCM images. RESULTS: Out of 260 equivocal 'pink' cutaneous lesions, there were 114 basal cell carcinomas within a total of 140 malignancies that included 12 melanomas, 13 squamous cell carcinomas, and 1 other malignancy type. Dermoscopy only evaluation resulted in an overall sensitivity of 85.1% and specificity of 92.4%, resulting in a positive predictive value (PPV) of 89.8%, with 1 of 12 melanomas misdiagnosed. RCM evaluation resulted in an overall sensitivity of 85.1% and specificity of 93.8%, resulting in a PPV of 91.5%, with no melanomas misdiagnosed. Combined dermoscopy-RCM evaluation resulted in an overall sensitivity of 77.2% and specificity of 96.6%, resulting in a PPV of 94.6%. CONCLUSION: The combination of dermoscopy-RCM evaluation significantly improves the accuracy and safety threshold in equivocal 'pink' cutaneous lesions in the differential diagnosis of basal cell carcinoma.

Colicin E1 forms a dimer after urea-induced unfolding.

Unfolding of the soluble colicin E1 channel peptide was examined with the use of urea as a denaturant; it was shown that it unfolds to an intermediate state in 8.5 M urea, equivalent to a dimeric species previously observed in 4 M guanidinium chloride. Single tryptophan residues, substituted into the peptide at various positions by site-directed mutagenesis, were employed as fluorescent probes of local unfolding. Unfolding profiles for specific sites within the peptide were obtained by quantifying the shifts in the fluorescence emission maxima of single tryptophan residues on unfolding and plotting them against urea concentration. Unfolding reported by tryptophan residues in the C-terminal region was not characteristic of complete peptide denaturation, as evidenced by the relatively blue-shifted values of the fluorescence emission maxima. Unfolding was also monitored by using CD spectroscopy and the fluorescent probe 2-(p-toluidinyl)-naphthalene 6-sulphonic acid; the results indicated that unfolding of helices is concomitant with the exposure of protein non-polar surface. Unfolding profiles were evaluated by non-linear least-squares curve fitting and calculation of the unfolding transition midpoint. The unfolding profiles of residues located in the N-terminal region of the peptide had lower transition midpoints than residues in the C-terminal portion. The results of unfolding analysis demonstrated that urea unfolds the peptide only partly to an intermediate state, because the C-terminal portion of the channel peptide retained significant structure in 8.5 M urea. Characterization of the peptide's global unfolding by size-exclusion HPLC revealed that the partly denatured structure that persists in 8.5 M urea is a dimer of two channel peptides, tightly associated by hydrophobic interactions. The presence of the dimerized species was confirmed by SDS/PAGE and intermolecular fluorescence resonance energy transfer.