Research Interests
Improving the safety of transfusable blood products
Although a rare occurrence, bacterial contamination of blood components, in particular of platelet concentrates, poses a significant post-transfusion infectious risk. Platelet concentrates are exquisitely susceptible to bacterial proliferation, due to their storage conditions in a nutrient-rich environment at ambient temperatures. The predominant bacteria present in platelet concentrates are commensal inhabitants of the human skin and are likely introduced at the time of blood collection. Despite efforts to prevent this, some contaminated blood components can slip through screening and other mitigation strategies and be used in transfusions. Therefore, our research primarily focuses on understanding why bacteria can withstand donor skin disinfection and avoid detection.
We have advanced knowledge and provided evidence-based data to improve processes and products and enhance transfusion patient safety in Canada and abroad. Some of our activities, include providing evidence to change blood donor skin disinfection protocols and implement processes such as platelet screening for bacterial contamination. Our studies have also supported the implementation of new products such as cold-stored platelet concentrates, and new processes such as pathogen inactivation of platelet concentrates. Research and development studies of major impact include the change of the 30-min rule for red blood cells and plasma to a 60-min rule, allowing for an extension of storage temperature excursion of these blood components. This was a welcome change by blood suppliers and hospitals worldwide to increase efficiency of product utilization without compromising patient safety. This work received recognition by the International Society of Blood Transfusion (ISBT) with the Best Paper Prize of Vox Sanguinis in 2013.
Advancing knowledge on the dynamics of bacterial growth during blood product storage
Our team has also pioneered work on the dynamics of bacterial growth during blood component storage. We have changed the paradigm of skin flora bacteria being harmless organisms. Our group was the first to discover that bacteria found on the skin, like Staphylococcus epidermidis, create communities of cells stuck to surfaces, known as biofilms, when storing platelet concentrates. This groundbreaking discovery paved the way for successful research. We have studied biofilm formation by other skin bacteria like Cutibacterium acnes and pathogenic organisms relevant to blood transfusion such as Staphylococcus aureus and Serratia marcescens.
Our recent studies have uncovered new information about how bacteria change at a molecular level when they grow in platelet concentrates. This leads to increased production of toxins, resistance to antimicrobial peptides and antibiotics, and higher secretion of inflammation-triggering molecules during platelet storage. These findings could have important implications for patients receiving transfusions.
Looking into the future
With global warming being a reality that has demonstrated migration of emergent pathogens, our lab will challenge itself by exploring a new field and expand its research and development scope to include studies with tickborne bacteria such as Anaplasma phagocytophilum, which can be transmitted by blood transfusion. We will also actively participate in the development and implementation of screening methods to interdict emergent viruses and parasites of relevance for transfusion patients. These new initiatives will allow us to prepare for the future and make an impact at national and international levels.
Selected Publications
- Ighem Chi S, Flint A, Weedmark K, Pagotto F, Ramirez-Arcos S. Comparative genome analyses of Staphylococcus aureus from platelet concentrates reveal rearrangements involving loss of type VII secretion genes. Access Microbiology, Volume 6, Issue 9. Published 13 September 2024.
- Yousuf B, Pasha R, Pineault N, Ramirez-Arcos S. Modulation of Staphylococcus aureus gene expression during proliferation in platelet concentrates with focus on virulence and platelet functionality. PLoS One. 2024 Jul 25;19(7):e0307920.
- Kumaran D, Ramirez-Arcos S. Cutibacterium acnes contamination does not enhance the proinflammatory profile of platelet concentrates. Transfusion. 2024;64:1437-1446.
- Ramirez-Arcos S, Kumaran D, Cap A, Cardenas KM, Cloutier M, Ferdin J, Gravemann U, Ketter P, Landry P, Lu T, Niekerk T, Parker J, Renke C, Seltsam A, Stafford B, Süssner S, Vollmer T, Zilkenat S, McDonald C; ISBT Transfusion‐Transmitted Infections Diseases Working Party, Subgroup on Bacteria. Proliferation of psychrotrophic bacteria in cold-stored platelet concentrates. Vox Sang. 2024 Apr 17. doi: 10.1111/vox.13640.
- Yousuf B, Flint A, Weedmark K, Pagotto F, Ramirez-Arcos S. Comparative virulome analysis of four Staphylococcus epidermidis strains from human skin and platelet concentrates using whole genome sequencing. Access Microbiol. 2024 Apr 3;6(4):000780.v3.
- Kou Y, Kumaran D, Howell A, Ramirez-Arcos S. (2024). Comparable bacterial growth in platelet concentrates suspended in plasma and platelet additive solution and improved detection of bacterial contamination using a new generation automated culture system. Transfusion 20024;64:665-673.
- Kumaran D, Ramirez-Arcos S. (2024) Sebum components dampen the efficacy of skin disinfectants against Cutibacterium acnes biofilms. Microorganisms. Jan 27;12(2):271.
- Ramirez-Arcos S, Garcia-Otalora M, McDonald C.; ISBT Transfusion-Transmitted Infectious Diseases Working Party, Subgroup on Bacteria. (2023). Microbiological environmental contamination in the blood supply chain: An international survey by the bacterial subgroup of the ISBT Transfusion-Transmitted Infectious Diseases Working Party. Vox Sang. 118:656-665. Editor’s Pick.
- Chi, SI, Ramirez-Arcos S (2022). Staphylococcal enterotoxins enhance biofilm formation by Staphylococcus aureus in platelet concentrates. Microorganisms Dec 29;11:89. doi: 10.3390/microorganisms11010089.
- Yousuf B, Pasha R, Pineault N, Ramirez-Arcos S (2022). Contamination of platelet concentrates with Staphylococcus aureus induces significant modulations in platelet functionality. Vox Sang. 117:1318-22.