Assessment of the microbiological quality of a preservative-free multidose system following a mixed culture microbial immersion challenge.

Current guidance on the microbiological qualification testing of preservative-free multidose ophthalmic systems is limited and lacking in detail with respect to methodology. This study describes the testing performed to assess the potential for biofilm formation on the tip of a preservative-free multidose device and the microbiological quality of the delivered dose following a mixed culture microbial immersion challenge, simulating a severe, repeated microbial exposure event. Biofilm was assayed quantitatively through viable microbial recovery, semi-quantitatively by staining the biomass in conjunction with ImageJ analysis, and qualitatively by microscopy.

Analysis of the capacity of Salmonella enterica Typhimurium to infect the human Placenta.

Introduction: Salmonella species are gram-negative facultative intracellular bacteria that are common causes of foodborne illness in North America. Infections by Salmonella during pregnancy are a significant cause of fetal loss in domestic livestock, and fetal and maternal mortality in mice. Furthermore, Salmonella infection is associated with miscarriage, stillbirth and preterm birth in pregnant women.

SLC11A1 is expressed in the human placenta across multiple gestational ages.

The human placenta functions as an innate immune barrier to prevent fetal infection. However, the molecular mechanisms accounting for placental resistance to pathogens are currently poorly understood. The solute carrier family 11 member 1 (SLC11A1) is a divalent cation transporter expressed primarily by macrophages and neutrophils that is essential for controlling infections by intracellular pathogens such as Salmonella, Leishmania and Mycobacteria.