Current trends in microbiology最新文献

N-terminal (Nt)-acylation is the irreversible addition of an acyl moiety to the terminal alpha amino group of a peptide chain. This type of modification alters the nature of the N terminus, which can interfere with the function of the modified protein by disrupting protein interactions, function, localization, degradation, hydrophobicity, or charge. Nt acylation is found in all domains of life and is a highly common occurrence in eukaryotic cells. However, in prokaryotes very few cases of Nt acylation have been reported. It was once thought that Nt acylation of proteins, other than ribosomal proteins, was uncommon in prokaryotes, but recent evidence suggests that this modification may be more common than once realized. In this review, we discuss what is known about prokaryotic Nt acetylation and the acetyltransferases that are responsible, as well as recent advancements in this field and currently used methods to study Nt acetylation.

SARS-CoV-2 vaccines aim to protect against COVID-19 through neutralizing antibodies against the viral spike protein. Mutations within the spike's receptor-binding domain may eventually reduce vaccine efficacy, necessitating periodic updates. Vaccine-induced immunity could be broadened by adding T cell-inducing antigens such as SARS-CoV-2's nucleoprotein (N). Here we describe two replication-defective chimpanzee adenovirus (AdC) vectors from different serotypes expressing SARS-CoV-2 N either in its wild-type form or fused into herpes simplex virus glycoprotein D (gD), an inhibitor of an early T cell checkpoint. The vaccines induce potent and sustained CD8⁺ T cell responses that are broadened upon inclusion of gD. Depending on the vaccine regimen booster immunizations increase magnitude and breadth of T cell responses. Epitopes that are recognized by the vaccine-induced T cells are highly conserved among global SARS-CoV-2 isolates indicating that addition of N to COVID-19 vaccines may lessen the risk of loss of vaccine-induced protection due to variants.

Prevention strategies and clinical management of methicillin- resistant Staphylococcus aureus (MRSA) infections in ventilated patients who develop ventilator-associated pneumonia (VAP) are important. Since MRSA are the most frequently isolated bacteria in patients with VAP, and a significant cause of morbidity and mortality in intubated patients, rapid diagnosis and early treatment could reduce mortality. This review will examine preventive steps (i.e. screening ventilated patients for MRSA, decolonization, and hand washing), assessing clinical presentations before the results of culture are obtained to direct empiric treatment, and the appropriate antibiotic therapy upon culture confirmation of MRSA that could help in the management of VAP.

Streptomycetes are very important industrial bacteria, which produce two thirds of all clinically relevant secondary metabolites. Furthermore, they produce large numbers of eukaryotic cell differentiation and apoptosis inducers. Streptomyces is a mycelial soil bacterium characterized by a complex developmental cycle that includes programmed cell death (PCD) phenomena and sporulation in solid cultures. Industrial fermentations are usually performed in liquid cultures, conditions in which Streptomyces strains generally do not sporulate, and it was traditionally assumed that there was no differentiation. Recently, novel aspects concerning differentiation during the presporulation phases were described in solid and liquid cultures, as well as in natural soils. In this review, we analyze the status of knowledge regarding the above-named aspects of Streptomyces differentiation and their relationships with secondary metabolite production.