Evolution of illness severity in hospital admissions due to COVID-19, Québec, Canada, January to April 2022.

Background: The coronavirus disease 2019 (COVID-19) severity is influenced by multiple factors, such as age, underlying medical conditions, individual immunity, infecting variant, and clinical practice. The highly transmissible Omicron variants resulted in decreased COVID-19 screening capacity, which limited disease severity surveillance.

Objective: To report on the temporal evolution of disease severity among patients admitted to Québec hospitals due to COVID-19 between January 2, 2022, and April 23, 2022, which corresponded to the peak period of hospitalizations due to Omicron.

Characterization of the Virulent Myophage ST32.

The virulent phage ST32 that infects the strain ST130 was isolated from a wastewater sample in China and analyzed. Morphological observations showed that phage ST32 belongs to the family, as it has an icosahedral capsid and long contractile tail. Host range analysis showed that it exhibits a broad range of hosts including non-pathogenic and pathogenic strains.

The Tape Measure Protein Is Involved in the Heat Stability of Lactococcus lactis Phages.

Virulent lactococcal phages are still a major risk for milk fermentation processes as they may lead to slowdowns and low-quality fermented dairy products, particularly cheeses. Some of the phage control strategies used by the industry rely on heat treatments. Recently, a few phages were found to be highly thermo-resistant.

Molecular Structure of Lactoferrin Influences the Thermal Resistance of Lactococcal Phages.

The protective effect of whey proteins on phages of lactic acid bacteria during heat treatment limits the recycling of whey proteins into cheese. To investigate this protective effect, we used lactoferrin (LF) as a whey protein model as a result of its unique physicochemical properties and its antiviral activity. First, the thermal inactivation of lactococcal thermoresistant virulent phage P1532 was measured in LF at 95 °C and under different pH values.

Investigation of the protective effect of whey proteins on lactococcal phages during heat treatment at various pH.

The incorporation of whey protein concentrates (WPC) into cheese is a risky process due to the potential contamination with thermo-resistant phages of lactic acid bacteria (LAB). Furthermore, whey proteins can protect phages during heat treatment, thereby increasing the above risk. The main objective of this work was to understand this protective effect in order to better control LAB phages and maximize whey recycling in the cheese industry.