drs. K.P. (Krzysztof) Trzcinski

drs. K.P. (Krzysztof) Trzcinski

Associate Professor
drs. K.P. (Krzysztof) Trzcinski
  • Infectious Diseases Research 4

Research Programs

Infection & Immunity



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.

Side Activities

MSD, Advisory Boards (from 2019 onwards), payments always to UMC Utrecht (>€2200,-)

Pfizer, speaker (2018), payment to UMC Utrecht (>€2200,-)

Pfizer, Advisory Board (2017), payment to UMC Utrecht (<€2200,-)

Fellowship and Awards


2000                 British Society for Antimicrobial Chemotherapy Research Fellowship

1999                 European Respiratory Society Research Fellowship

1998                 Royal Society/NATO Research Fellowship

1997                 Award of the European Congress of Clinical Microbiology and Infectious Diseases, Lausanne, Switzerland

1994                 European Society of Clinical Microbiology and Infectious Diseases Young Scientist Research Fellowship

Research Output (90)

Saliva as an alternative sample type for detection of pneumococcal carriage in young children

Wyllie Anne L, Rots Nynke Y, Wijmenga-Monsuur Alienke J, van Houten Marlies A, Sanders Elisabeth A M, Trzciński Krzysztof Oct 2023, In: Microbiology. 169 , p. 1-8 8 p.

Meningococcal carriage in children and young adults:a cross-sectional and longitudinal study, Iceland, 2019 to 2021

Kristinsdottir Iris, Visser Linda J, Miellet Willem R, Mariman Rob, Pluister Gerlinde, Haraldsson Gunnsteinn, Haraldsson Asgeir, Trzciński Krzysztof, Thors Valtyr 28 Sep 2023, In: Eurosurveillance. 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

Miellet Willem R, Pluister Gerlinde, Sikking Meike, Tappel Marcia, Karczewski Jurgen, Visser Linda J, Bosch Thijs, Trzciński Krzysztof, Mariman Rob 7 Jul 2023, In: Vaccine. 41 , p. 4927-4932 6 p.

A spitting image: molecular diagnostics applied to saliva enhance detection of Streptococcus pneumoniae and pneumococcal serotype carriage

Miellet Willem R, van Veldhuizen Janieke, Litt David, Mariman Rob, Wijmenga-Monsuur Alienke J, Nieuwenhuijsen Tessa, Christopher Jennifer, Thombre Rebecca, Eletu Seyi, Bosch Thijs, Rots Nynke Y, van Houten Marianne Alice, Miller Elizabeth, Fry Norman K, Sanders Elisabeth A M, Trzciński Krzysztof 17 Apr 2023, In: Frontiers in Microbiology. 14 13 p.

Streptococcus pneumoniae carriage studies in adults:Importance, challenges, and key issues to consider when using quantitative PCR-based approaches

Miellet Willem, Almeida Sónia T, Trzciński Krzysztof, Sá-Leão Raquel 16 Feb 2023, In: Frontiers in Microbiology. 14 8 p.

Pneumococcal genetic variability in age-dependent bacterial carriage

Kremer Philip H C, Ferwerda Bart, Bootsma Hester J, Rots Nienke Y, Wijmenga-Monsuur Alienke J, Sanders Elisabeth A M, Trzciński Krzysztof, Wyllie Anne L, Turner Paul, van der Ende Arie, Brouwer Matthijs C, Bentley Stephen D, van de Beek Diederik, Lees John A 26 Jul 2022, In: eLife. 2022 , p. 1-20

High Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Household Transmission Rates Detected by Dense Saliva Sampling

Kolodziej L M, van Lelyveld S F L, Haverkort M E, Mariman R, Sluiter-Post J G C, Badoux P, de Koff E M, Koole J C D, Miellet W R, Swart A N, Coipan E C, Meijer A, Sanders E A M, Trzciński K, Euser S M, Eggink D, van Houten M A 15 May 2022, In: Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 75 , p. e10-e19

It Takes Two to Tango:Combining Conventional Culture With Molecular Diagnostics Enhances Accuracy of Streptococcus pneumoniae Detection and Pneumococcal Serogroup/Serotype Determination in Carriage

Miellet Willem R., van Veldhuizen Janieke, Litt David, Mariman Rob, Wijmenga-Monsuur Alienke J., Badoux Paul, Nieuwenhuijsen Tessa, Thombre Rebecca, Mayet Sanaa, Eletu Seyi, Sheppard Carmen, van Houten Marianne Alice, Rots Nynke Y., Miller Elizabeth, Fry Norman K., Sanders Elisabeth A.M., Trzciński Krzysztof 18 Apr 2022, In: Frontiers in Microbiology. 13

Pneumococcal carriage in unvaccinated children at the time of vaccine implementation into the national immunization program in Poland

Wróbel-Pawelczyk Izabela, Ronkiewicz Patrycja, Wanke-Rytt Monika, Rykowska Dominika, Górska-Kot Aneta, Włodkowska Katarzyna, Topczewska-Cabanek Agnieszka, Jackowska Teresa, Chruszcz Joanna, Marchut Walentyna, Mastalerz-Migas Agnieszka, Korzeniewski Krzysztof, Gastoł Karolina, Gromek Marta, Jankowska-Sasin Katarzyna, Karpierz Katarzyna, Okarska-Napierała Magdalena, Pokorna-Kałwak Dagmara, Polit Agata, Robakiewicz Julia, Rygalski Maciej, Siwonia Anna, Strzałka Martyna, Szenborn Leszek, Szwejkowska Martyna, Szymańska-Toczek Zofia, Zaleska Izabela, Żołnierowicz Katarzyna, Skoczyńska Anna, Trzciński Krzysztof, 7 Apr 2022, In: Scientific Reports. 12

Approximate likelihood-based estimation method of multiple-type pathogen interactions:An application to longitudinal pneumococcal carriage data

Man Irene, Bogaards Johannes A, Makwana Kishan, Trzciński Krzysztof, Auranen Kari 15 Mar 2022, In: Statistics in Medicine. 41 , p. 981-993 13 p.

All research output

Thank you for your review!

Has this information helped you?

Please tell us why, so that we can improve our website.

Working at UMC Utrecht





Practical uses cookies

This website uses cookies This website displays videos from, among others, YouTube. Such parties place cookies (third-party cookies). If you do not want these cookies, you can indicate that here. We also place cookies ourselves to improve our site.

Read more about the cookie policy

Agree No, rather not