Profile photo Krzysztof Trzcinski

Krzysztof Trzcinski

Associate Professor

Strategic program(s):


Dr Krzysztof Trzciński, is a microbiologist and Principal Investigator in the Respiratory Infections Research Group at the University Medical Centre Utrecht (UMCU).

Before taking up the position of Associate Professor at the Department of Pedatric Immunology and Infectious Diseases at UMCU in 2009, he worked as a Senior Research Scientist at Harvard T.H. Chan School of Public Health, Boston, Massachusetts.

His main area of interest is Streptococcus pneumoniae (pneumococcus), whether it be a respiratory pathogen, or human commensal. Despite available vaccines targeting pneumococcal disease, S. pneumoniae remains one of the top causes of death due to bacterial respiratory infections.

In his work, Dr Trzciński focuses on innate and acquired immune responses to natural colonization with S. pneumoniae, as well as mechanisms maintaining the diversity of pneumococcal capsular types (serotypes) circulating and causing disease in the human population. He is using both experimental and epidemiological approaches in his research. With his work, he contributed to the discovery that naturally acquired mucosal immunity to pneumococcal colonization is largely antibody-independent (Trzciński et al. Infect.Immun. 2005), yet antigen-specific (Trzciński et al. Infect.Immun. 2008), while transcending serotypes (Malley et al. PNAS 2005). These findings opened new opportunities in developing vaccines (Li et al. PLoS Path. 2012). Also, utilizing pneumococcal strains that differ only by serotype (Trzciński et al. App.Env.Microbiol. 2003), he and his co-workers showed that simple characteristics of the capsular polysaccharide allow predictions of prevalence of a serotype in carriage (Weinberger et al. PLoS Path. 2009, Li et al. Infect.Immun. 2013, Trzciński et al. MBio 2015) and invasiveness in disease (Hyams et al. Infect.Immun. 2013), and that capsular characteristics could be linked to variations in S. pneumoniae resistance to certain immune responses: opsonin-independent killing of pneumococci by neutrophils (Weinberger et al. PLoS Path. 2009) and the deposition of complement and opsonophagocytosis (Melin et al. Infect. Immun. 2010a; Melin et al. Infect.Immun. 2010b, Hyams et al. Infect.Immun. 2013). He also contributed to better understanding the factors mediating interaction between pneumoocci and other pathogens colonizing the upper respiratory tract, Staphylococcus aureus in particular (Regev-Yochay et al. J.Bac. 2006, Selva et al. PNAS 2009).

Currently, he is developing enhanced methods for pneumococcal colonization detection, and for studying multi-serotype carriage (Trzciński et al. PLoS ONE, 2013, Wyllie et al. PLoS ONE 2014, Krone et al. PLoS ONE 2015, Trzciński et al. MBio 2015, Miellet et al. CID 2021, Miellet et al. Front.Microbiol. 2022). 

With his work, Dr Trzciński aims to broaden our understanding of the interactions between S. pneumoniae and the host during colonization and infection, and enhance the knowledge necessary to assess accurately the effects of preventative strategies targeting pneumococcal disease.

Recent publications

Impact of age on pneumococcal colonization of the nasopharynx and oral cavity: an ecological perspective Willem R Miellet, Rob Mariman, Janieke van Veldhuizen, Paul Badoux, Alienke J Wijmenga-Monsuur, David Litt, Thijs Bosch, Elizabeth Miller, Norman K Fry, Marianne A van Houten, Nynke Y Rots, Elisabeth A M Sanders, Krzysztof Trzciński
ISME communications, 2024, vol. 4
Meningococcal carriage in children and young adults Iris Kristinsdottir, Linda J Visser, Willem R Miellet, Rob Mariman, Gerlinde Pluister, Gunnsteinn Haraldsson, Asgeir Haraldsson, Krzysztof Trzciński, Valtyr Thors
Eurosurveillance, 2023, vol. 28
Surveillance of Neisseria meningitidis carriage four years after menACWY vaccine implementation in the Netherlands reveals decline in vaccine-type and rise in genogroup e circulation Willem R Miellet, Gerlinde Pluister, Meike Sikking, Marcia Tappel, Jurgen Karczewski, Linda J Visser, Thijs Bosch, Krzysztof Trzciński, Rob Mariman
Vaccine, 2023, vol. 41, p.4927-4932
Streptococcus pneumoniae carriage studies in adults Willem Miellet, Sónia T Almeida, Krzysztof Trzciński, Raquel Sá-Leão
Frontiers in Microbiology, 2023, vol. 14
Saliva as an alternative sample type for detection of pneumococcal carriage in young children Anne L Wyllie, Nynke Y Rots, Alienke J Wijmenga-Monsuur, Marlies A van Houten, Elisabeth A M Sanders, Krzysztof Trzciński
Microbiology, 2023, vol. 169, p.1-8
A spitting image: molecular diagnostics applied to saliva enhance detection of Streptococcus pneumoniae and pneumococcal serotype carriage Willem R Miellet, Janieke van Veldhuizen, David Litt, Rob Mariman, Alienke J Wijmenga-Monsuur, Tessa Nieuwenhuijsen, Jennifer Christopher, Rebecca Thombre, Seyi Eletu, Thijs Bosch, Nynke Y Rots, Marianne Alice van Houten, Elizabeth Miller, Norman K Fry, Elisabeth A M Sanders, Krzysztof Trzciński
Frontiers in Microbiology, 2023, vol. 14