Bacterial interactions across a porous membrane

Deepening our knowledge about bacterial infections is of high priority in the work against antimicrobial resistance. Many infections are as well polymicrobial, and the different bacterial species are able to affect each other by cell-cell communication. This is a phenomenon that in several cases is known to enhance the virulence and the severity of the infection. Therefore, new approaches to study bacterial interactions are needed. In this project we have designed a bacterial growth chamber with a porous membrane as a separating wall between two bacterial species. This gave us the ability to discriminate what molecules that can be exchanged between the bacterial cultures by choosing the membrane properties. The setup allows the two bacterial cultures to be spatially separated, yet chemically connected via diffusion through the growth medium and the porous membrane. Two different kinds of hydrophilic membranes were chosen for investigation of their performance as filters in this membrane setup for bacterial growth: a block copolymer based membrane with a pore size of 10 nm and commercially available Millipore membranes with two pore sizes of 220 and 450 nm respectively. The studied bacterial interaction is between Pseudomonasaeruginosa and Staphylococcus aureus, two commonly found bacterial species in the lungs of patients with Cystic Fibrosis and in chronic wounds. We could conclude that bacterial interspecies cell-cell communication through a membrane was possible in our setup. Further, a double membrane setup with a water phase in between the membranes, showed the same bacterial interaction. This last setup enabled molecular analysis of the water phase and thereby the signal molecules.Kan man tjuvlyssna på bakteriers kommunikation? - I infektioner finns ofta flera olika sorters bakterier och de kommunicerar med varandra. Detta kan förvärra infektionen och leda till antibiotikaresistens. Nya metoder behövs därför för att ta reda på mer om de signalmolekyler som bakterier använder för att kommunicera

SARS-CoV-2 in size-fractionated aerosols from hospital corridors and relations to the indoor environment

The aim of the current study was to evaluate the presence of airborne virus, specifically SARS-CoV-2, in infection ward corridors, and the size distribution of the virus-containing aerosols. Associations between virus presence and relative humidity and/or temperature in the facilities was also investigated

Airborne SARS-CoV-2 during childbirth

Airborne SARS CoV 2 is considered to play a major role in covid 19 transmission, and has been found in several hospital environments. There is a need to investigate the presence of airborne SARS CoV 2 in other hospital areas than traditional infectious disease wards. The results from the present study can contribute to a better understanding of the risk of covid 19 transmission by aerosols at delivery wards

Characteristics of SARS-CoV-2-containing aerosols in hospital corridors

The aim of this work is to investigate the presence of airborne SARS-CoV-2 in corridors of infection wards, and gain more detailed size information of SARS-CoV-2-containing aerosols. Associations between SARS-CoV-2 presence and relative humidity and/or temperature in the facilities is also explored

Airborne SARS-CoV-2 RNA collected during childbirth and autopsy

Airborne SARS-CoV-2 is considered to play a major role in covid-19 transmission, and several studies have reported its presence in hospital environments, including corridors, patient rooms, cohort rooms and ICUs (Dinoi et al., 2022). The risk of airborne virus have been associated with a number of factors, such as low ventilation, high patient viral load and in some cases, certain medical procedures.However, specific medical situations still deserve further investigation. One such situation of interest is childbirth, as respiratory emissions, which could contain virus, are increased due to heavy breathing during labor. Another situation with potential risk for airborne SARS-CoV-2 is autopsy.The aim of the current study was to further explore the presence of airborne SARS-CoV-2 RNA during childbirth and autopsy.The results in this study can increase our understanding about the risk of covid-19 transmission by aerosols at delivery wards and during autopsy, even though the sample material is small. Reports of airborne SARS-CoV-2 in hospital environments contribute to improving guidelines for protective equipment for healthcare personnel working with such patients

Longitudinal, size-resolved air sampling of SARS-CoV-2 in hospital corridors and relations to the indoor environment

The aim of this work is to investigate the presence of airborne SARS-CoV-2 in corridors of infection wards, and gain more detailed size information of SARS-CoV-2-containing aerosols. Associations between SARS-CoV-2 presence and relative humidity and/or temperature in the facilities is also explored