Viruses

Parvovirus B19 (B19V) is a human ssDNA virus with ample pathogenic potential. It is characterized by a selective tropism for erythroid progenitor cells (EPC), exerting a cytotoxic effect with blockade of erythropoiesis. In our work, we investigated both viral and cellular expression profile in the course of infection of EPCs cultures via mRNA high throughput sequencing technology (HTS) and a dedicated bioinformatic pipeline, reconstructing both the viral and cellular transcriptome and their variations. A productive infection was confirmed as restricted to EPCs expressing mature differentiation markers and the specific receptor for virus VP1u region. mRNA HTS reconstructed the viral transcriptome in terms of localization and abundance of the different mRNA species, detailing the differential expression profile of B19V among early or late times in the course of infection. Analysis of cellular transcriptome indicated that variation was mainly driven by the cellular differentiation process, with the virus impacting to a lesser level, but still clearly separating infected vs. non-infected profiles. At early times post-infection, variations were typical of cellular sensing of viral infection and aimed at the induction of an antiviral state. At later times in the course of infection, the cellular population showed induction of an inflammatory response, related to TNF and IL-10, and a transition to adaptive immunity with evidence of upregulation of genes involved in MHC-II presentation. This dual-transcriptome analysis on infected EPCs population can lay the ground for future research aimed at a better definition of the pathogenetic mechanisms of B19V.

Bacteriophages, often referred to as “bacteria eaters,” have gained renewed interest as a powerful alternative to traditional antibiotics, particularly in addressing antibiotic-resistant bacterial infections. The present review summarizes data collected in Bulgaria during the 1960s, 1970s, and 1980s, drawing connections between past findings and present-day understanding of cytotoxicity and the clinical validation of bacteriophage applications. Its sections describe phage structure, mechanisms of action, and historical findings both globally and within the Bulgarian context, while also highlighting emerging trends and applications. The cited studies delve into the past through contemporary research contributions related to “Bulgarian phages”, a topic that remains underexplored in existing literature. The role of phages in medical microbiology is discussed alongside the challenges of therapeutic implementation, with particular focus on insights gained from the Bulgarian experience. In conclusion, by fostering international collaborations, investing in infrastructure, and establishing supportive policies, bacteriophage therapy can emerge as a critical tool for managing bacterial infections and reducing the global burden of antibiotic resistance in the future.

Pandemics have claimed millions of lives over millennia [...]