Coronavirus disease 19, or COVID-19, is an infection associated with an unprecedented worldwide pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which has led to more than 215 million infected people and more than 4.5 million deaths worldwide. SARS-CoV-2 cell infection is initiated by a densely glycosylated spike (S) protein, a fusion protein, binding human angiotensin converting enzyme 2 (hACE2), that acts as the functional receptor through the receptor binding domain (RBD). In this article, the interaction of hACE2 with the RBD and how fusion is initiated after recognition are explored, as well as how mutations influence infectivity and immune response. Thus, we focused on all structures available in the Protein Data Bank for the interaction between SARS-CoV-2 S protein and hACE2. Specifically, the Delta variant carries particular mutations associated with increased viral fitness through decreased antibody binding, increased RBD affinity and altered protein dynamics. Combining both existing mutations and mutagenesis studies, new potential SARS-CoV-2 variants, harboring advantageous S protein mutations, may be predicted. These include mutations S13I and W152C, decreasing antibody binding, N460K, increasing RDB affinity, or Q498R, positively affecting both properties.

Dirofilaria immitis is a zoonotic parasitic nematode that infects domestic and wild canids, among its vertebrate hosts. The genetic analysis of D. immitis nowadays transcends the need for genetic taxonomy of nematodes, such as the study of resistance to macrocyclic lactone. We expanded the use of long-read nanopore-based sequencing technology on nematodes by performing genomic de novo assembly of a D. immitis specimen retrieved from a canine cardiopulmonary dirofilariasis case using the ONT MinION platform, followed by the study of macrocyclic lactone resistance. The assembled genome of D. immitis consists of 110 contigs with an N50 of 3687191. The genome size is 87899012 and contains a total of 9741 proteins; 6 ribosomal RNAs, with three belonging to the small subunit (18S) and three to the large subunit (28S); and 73 tRNAs. Subsequent analysis of six loci previously characterized as being associated to macrocyclic lactone resistance selection pressure showed that four have a genotype associated with either some loss of efficacy or the resistance phenotype. Considering the zoonotic potential of D. immitis, the identification of a resistant parasite alerts for the overuse of macrocyclic lactone in the region, which poses a potential risk to both veterinary and human public health.

Introduction Norovirus gastroenteritis is one of the most frequent causes of personnel unavailability in military units, being associated with significant morbidity and degradation of their operational effectiveness. The disease is usually mild but can be severe and life-threatening in young and healthy soldiers, who are prone to dehydration due to intensive daily activity. Despite its impact, the full extent of the norovirus gastroenteritis burden in military forces remains unclear. This systematic review aims to evaluate the impact and ascertain clinical and epidemiological features of norovirus outbreaks that have occurred in the military forces. Methods The systematic review followed the Preferred Reporting Items for Systemic Reviews and Meta-Analysis (PRISMA) guidelines and used three databases: PubMed, Scopus, and LILACs. Papers published up to 1 September 2019 were included without restrictions if they reported one or more outbreaks in the military forces on active duty, either on national territories or deployed overseas. Results A total of 343 papers were retrieved from the literature search. After inclusion/exclusion criteria a total of 39 eligible papers were considered. From 1988 (first reported outbreak in the military) to 2018 more than 101 norovirus outbreaks have been reported in the military, accounting for at least 24 332 cases. Secondary transmission was emphasised as the main route of norovirus transmission in the military forces, with eating outside the military setting an important route for the primary cases. Conclusions The present review highlights that norovirus gastroenteritis has been a burden to military troops both in combat and on peacekeeping operations. Norovirus disease has been shown to exact a substantial toll on mission readiness and operational effectiveness. It is noteworthy that the impact of norovirus outbreaks among military units is underestimated because the literature review retrieved information from the armed forces from only nine countries.

Collagen, the most abundant structural protein in animals, is fundamental for tissue integrity and regeneration. Conventional mammalian sources face limitations related to sustainability, safety, and ethical concerns, underscoring the need for alternative biomaterials. Marine organisms, particularly jellyfish, offer a promising eco-friendly collagen source. In this study, collagen and collagen-derived peptides were extracted from the cnidarian Physalia physalis and biochemically characterized. Circular dichroism demonstrated partial loss of triple-helix structure, while SDS-PAGE revealed type I collagen related α-chains together with low-molecular-weight fragments. The hydrolyzed collagen fractions exhibited keratinocyte and fibroblast cytocompatibility and increased keratinocyte migration. Moreover, P. physalis-derived peptides modulated inflammatory cytokine release in lipopolysaccharide-stimulated macrophages reducing tumor necrosis factor (TNF)-α by 38% and increasing interleukin (IL)-10 by 29%. Based on these results, a stable bioactive serum formulation incorporating P. physalis collagen peptides was developed. Overall, this work demonstrates that bioactive peptides from P. physalis possess immunomodulatory and regenerative potential and represent a promising new marine resource for cosmetic applications.

The key viral protein for infection by SARS-CoV-2 is the spike glycoprotein (S protein), mediating entry into host cells, which therefore represents a strong focus for the development of targeted therapeutics. In this work, we explored the fatty acid binding pocket within the S protein, which stabilizes an inactive conformation and disrupts cell recognition and infection. To explore the potential of this site as a drug target, molecular dynamics simulations were performed, followed by a docking-based virtual screening of commercial druglike compounds. This in silico procedure enabled the identification of potential inhibitors of SARS-CoV-2 cell infection, likely by stabilizing an inactive spike conformation, detected in binding assays, although further experiments are required to directly confirm this action. The antiviral effect of the virtual hits was analyzed in cell-based assays, and one molecule displayed a low micromolar activity. Starting from the best antiviral compound found, structural analogues were purchased and evaluated in antiviral assays. An increase in activity was observed for multiple analogues, with the strongest antiviral compound showing submicromolar activity and low cytotoxicity. The successful identification of a new antiviral scaffold through in silico studies might pave the way for the further development of antivirals against SARS-CoV-2 and shows the reliability of the methodologies applied.