N-chlorotaurine is highly active against respiratory viruses including SARS-CoV-2 (COVID-19) in vitro

Antibiotic Therapy for Pulmonary Exacerbations in Cystic Fibrosis-A Single-Centre Prospective Observational Study

People with cystic fibrosis experience bronchopulmonary exacerbations, leading to lung damage, lung function decline, increased mortality, and a poor health-related quality of life. To date, there are still open questions regarding the rationale for antibiotic use and the optimal duration of antibiotic therapy. This prospective single-center study (DRKS00012924) analyzes exacerbation treatment over 28 days in 96 pediatric and adult people with cystic fibrosis who started oral and/or intravenous antibiotic therapy in an inpatient or outpatient setting after clinician diagnosis of bronchopulmonary exacerbation. Biomarkers of exacerbation were examined in terms of their ability to predict response to treatment and the need for antibiotic therapy. The mean duration of antibiotic therapy was 14 days. Inpatient treatment was associated with a poorer health status, but no significant difference was found in the modified Fuchs exacerbation score between inpatients and outpatients. A significant increase of in-hospital FEV1, home spirometry FEV1, and body-mass index and a significant decrease of the modified Fuchs symptom score, C-reactive protein, and 8 out of the 12 domain scores of the revised cystic fibrosis questionnaire were demonstrated after 28 days. However, a trend towards a FEV1 decline in the inpatient group on day 28 could be demonstrated, while FEV1 was maintained in the outpatient group. Correlation analyses of changes between baseline and day 28 show a strong positive correlation between home spirometry and in-hospital FEV1, strong negative correlations between FEV1 and the modified Fuchs exacerbation score and between FEV1 and C-reactive protein, and a moderately negative correlation between FEV1 and the three domains of the revised cystic fibrosis questionnaire. Responders and non-responders to antibiotic therapy were defined in terms of FEV1 improvement after therapy. A higher baseline C-reactive protein, a greater decrease in C-reactive protein, a higher baseline modified Fuchs exacerbation score, and a greater decrease in the score after 28 days could be found in the responder group, while other baseline and follow-up parameters like FEV1 showed no significant differences. Our data show that the modified Fuchs exacerbation score is applicable in a clinical setting and can detect acute exacerbations regardless of health status. Home spirometry is a useful tool for outpatient exacerbation management. A change in C-reactive protein and a modified Fuchs score change are suitable follow-up markers of exacerbation due to their strong correlation with FEV1. Further studies are needed to assess which patients would benefit from a longer duration of antibiotic therapy. C-reactive protein at exacerbation onset and C-reactive protein decline during and after therapy better predict antibiotic therapy success than FEV1 at therapy onset, while the modified Fuchs score indicates exacerbation regardless of the need for antibiotic therapy, suggesting that antibiotic therapy is only part of exacerbation management.

Antimicrobial efficacy, mode of action and in vivo use of hypochlorous acid (HOCl) for prevention or therapeutic support of infections

The objective is to provide a comprehensive overview of the rapidly developing field of the current state of research on in vivo use of hypochlorous acid (HOCl) to aid infection prevention and control, including naso-pharyngeal, alveolar, topical, and systemic HOCl applications. Also, examples are provided of dedicated applications in COVID-19. A brief background of HOCl's biological and chemical specifics and its physiological role in the innate immune system is provided to understand the effect of in vivo applications in the context of the body's own physiological defense mechanisms.

Recombinant actin-depolymerizing factor of the apicomplexan Neospora caninum (NcADF) is susceptible to oxidation

Neospora caninum is a member of Apicomplexa Phylum and the causative agent of neosporosis, a disease responsible for abortions in cattle. Apicomplexan parasites have a limited set of actin-binding proteins conducting the regulation of the dynamics of nonconventional actin. The parasite actin-based motility is implicated in the parasite invasion process in the host cell. Once no commercial strategy for the neosporosis control is available, the interference in the parasite actin function may result in novel drug targets. Actin-depolymerization factor (ADF) is a member of the ADF/cofilin family, primarily known for its function in actin severing and depolymerization. ADF/cofilins are versatile proteins modulated by different mechanisms, including reduction and oxidation. In apicomplexan parasites, the mechanisms involved in the modulation of ADF function are barely explored and the effects of oxidation in the protein are unknown so far. In this study, we used the oxidants N-chlorotaurine (NCT) and H₂O₂ to investigate the susceptibility of the recombinant N. caninum ADF (NcADF) to oxidation. After exposing the protein to either NCT or H₂O₂, the dimerization status and cysteine residue oxidation were determined. Also, the interference of NcADF oxidation in the interaction with actin was assessed. The treatment of the recombinant protein with oxidants reversibly induced the production of dimers, indicating that disulfide bonds between NcADF cysteine residues were formed. In addition, the exposure of NcADF to NCT resulted in more efficient oxidation of the cysteine residues compared to H₂O₂. Finally, the oxidation of NcADF by NCT reduced the ability of actin-binding and altered the function of NcADF in actin polymerization. Altogether, our results clearly show that recombinant NcADF is sensitive to redox conditions, indicating that the function of this protein in cellular processes involving actin dynamics may be modulated by oxidation.

Virucidal properties of new multifunctional fibrous N-halamine-immobilized styrene-divinylbenzene copolymers

Virucidal properties of N-chlorosulfonamides immobilized on fibrous styrene-divinylbenzene copolymers have been studied. Corresponding materials with different functional group structures and chlorine content have been synthesized on FIBAN polymer carriers in the form of staple fibers and non-woven fabrics. The study has been conducted in general accordance with EN 14476 standard on poliovirus type-1 and adenovirus type-5. It has been found that all tested samples exhibit pronounced virucidal activity: regardless of the carrier polymer form, sodium N-chlorosulfonamides inactivated both viruses in less than 30 s, and N,N-dichlorosulfonamides—in 30–60 s. The main mechanism of action of these materials, obviously, consists in the emission of active chlorine from the functional group into the treated medium under the action of the amino groups of virus fragments and cell culture. Considering the previously described antimicrobial and reparative properties of such materials, as well as their satisfactory physical and mechanical properties, the synthesized polymers are promising for the creation of medical devices with increased resistance to microbial contamination, such as protective masks, filter elements, long-acting wound dressings, and others.

Comparative Fungicidal Activities of N-Chlorotaurine and Conventional Antiseptics against Candida spp. Isolated from Vulvovaginal Candidiasis

N-chlorotaurine (NCT), the N-chloro derivative of the amino acid taurine, is a long-lived oxidant produced by stimulated human leucocytes. NCT has antimicrobial activities which are generally enhanced in the presence of organic material. The aim of this study was to investigate fungicidal effects of NCT and conventional antiseptics against Candida isolated from vulvovaginal candidiasis (VVC). Chlorhexidine (CHX, 1.6%), octenidine dihydrochloride (OCT, 0.08%), povidone iodine (PVP-I, 8%), boric acid (8%), and NCT (0.1% (5.5 mM)) were evaluated against forty-four Candida isolates, according to European Standard methods, at 30, 60, 90, and 120 min and 24 h in the presence of skim milk as an organic material. CHX, OCT, and PVP-I showed rapid fungicidal activity against all Candida isolates with 5–6 log10 reduction of viable counts after 30 min, whereas boric acid and NCT needed 1 h against Candida albicans and 2 h against non-albicans Candida for a significant 3 log10 reduction. NCT showed fungicidal activity (defined as ≥4 log10 reduction) against C. albicans within 90 min and C. non–albicans within 24 h. Based upon all presently available data, including our results, NCT could be used as a new agent for treatment of local fungal infections such as VVC.