Research

My research leverages clinical metadata and whole-genome sequencing to study the evolution and spread of antibiotic resistant bacteria in hospital and community settings.

For the complete list of my publications, please visit my Google Scholar profile.

Microbial evolution

I leverage whole-genome sequencing data, phylogenetics, and epidemiological methods to evaluate the evolution of bacterial pathogens.
Primarily focusing on the evolution of antibiotic resistance, I am also interested in the genomic drivers of bacterial infections.

  1. Gontjes K, Singh A, Sansom SE, Boyko J, Smith SA, Lautenbach E, Snitkin E. Phylogenetic context of antibiotic resistance provides insights into the dynamics of resistance emergence and spread. Journal of Infectious Diseases. 2025. link
  2. Gontjes K, …, Lautenbach E, Snitkin E. Identifying drivers of β-lactam/β-lactamase inhibitor resistance emergence and spread before their clinical deployment. medRxiv. link
  3. Boyko J, Gontjes K, Snitkin E, Smith SA. Uncertainty in joint ancestral state reconstruction: Improving accuracy and biological interpretability of ancestral state prediction. bioRxiv. link
  4. Unverdorben LV, Pirani A, Gontjes K, Moricz B, Holmes CH, Snitkin ES, Bachman MA. Klebsiella pneumoniae evolution in the gut leads to spontaneous capsule loss and decreased virulence potential. mBio, 2025. link

Microbial genomic epidemiology

I leverage observational and intervention studies to evaluate the distribution and determinants of colonization and infection with antibiotic-resistant organisms.
Alongside descriptive analyses, I develop novel research methodologies and translational infection prevention research.

  1. Lapp Z, … Gontjes K, …, Evan Snitkin, Rachel B Slayton. Distinct Origins and Transmission Pathways of blaKPC Enterobacterales across Three U.S. States. J Clin Microbiol. 2023. link
  2. Zhang HL, Gontjes K, Han JH, Alby K, Lapp Z, Snitkin S, Goldstein EJC, Muldoon S, Tolomeo P, Lautenbach E. Resistance phenotypes of carbapenem-resistant Klebsiella pneumoniae in a multi-state network of long-term acute care hospitals. Infect Control Hosp Epidemiol. 2022. link

Translational infection prevention research

Alongside my research on the genomic epidemiology of antibiotic-resistance organisms, I have also conducted translational infection prevention research to characterize the epidemiology and risk factors for colonization with antibiotic-resistant bacteria.

  1. Gontjes K, Gibson KE, Lansing B, Karen J, Cassone M, Wang J, Mills J, Mody L, Patel K. Association of exposure to high-risk antibiotics in acute care hospitals with multidrug-resistant organism burden in nursing homes. JAMA Network Open, 2022. link
  2. Mody L, Gontjes K, Cassone M, Gibson KE, Lansing B, Mantey J, Kabeto M, Galecki A, Min L. Effectiveness of a Multicomponent Intervention to Reduce Multidrug-Resistant Organisms in Nursing Homes: A Cluster Randomized Clinical Trial. JAMA Network Open, 2021. link
  3. Gontjes K, Gibson KE, Lansing B, Mody L, Cassone M. Can alternative anatomical sites and environmental surveillance replace perianal screening for multidrug-resistant organisms in nursing homes? Infect Control Hosp Epidemiol, 2021. link
  4. Gontjes K, Gibson KE, Lansing B, Mody L, Cassone M. Assessment of Race and Sex as Risk Factors for Colonization with Multidrug-Resistant Organisms in Six Nursing Homes. Infect Control Hosp Epidemiol, 2020. link
  5. Gontjes K, Gibson KE, Lansing B, Cassone M, Mody L. Contamination of Common Area and Rehabilitation Gym Environment with Multidrug-Resistant Organisms. J Am Geriatric Soc., 2020. link

Public health education

Alongside my genomic epidemiology research, I am interest in understanding interest and confidence in public health.
To accomplish this, I have led the deployment of two surveys to gauge young adult voices on public health, health education, and infection prevention related topics.

  1. Mody M, Gontjes K. Health Education After COVID-19: A Time to Revisit, Revamp, and Revitalize? A J Infect Control, 2022. link
  2. Mody M, Hodges AN, Gibson KE, Mantey J, Gontjes K. Does high school health education class satisfaction influence student perceptions of public health and pandemic response? A J Infect Control. 2024. link

Cultural commentaries

I also enjoy writing about a variety of topics. I’ve published commentaries on the role of grace in medicine.
Feel free to reach out if you’d like to discuss these subjects or collaborate on a commentary!

  1. Gontjes K, Collier K. From a Culture of Blame to a Culture of Grace: A Letter in Reply to Papadakis. Infect Control Hosp Epidemiol, August 2021. link