The University of Basel and University Hospital Basel have conducted a study shedding light on the persistence of antibiotic-resistant bacteria in the human body over extended periods.

1. Study Reveals Resistant Bacteria
Persistence in the Body Over Years
Resilient Bacteria Pose Long-term Health Threat
The University of Basel and University Hospital Basel have conducted a study shedding light on
the persistence of antibiotic-resistant bacteria in the human body over extended periods. The
research highlights the challenges posed by these resilient pathogens, particularly for individuals
with underlying health conditions. Diseases like pneumonia, urinary tract infections, and sepsis,
which typically require antibiotic treatment, become increasingly difficult to manage when
bacteria develop resistance to common antibiotics like penicillins and cephalosporins.
Long-Term Analysis of Bacterial Adaptation
Professor Sarah Tschudin Sutter’s research group examined samples from over 70 individuals
over a span of ten years, focusing on older adults with pre-existing health issues. The study aimed
to understand how resistant Klebsiella pneumoniae and Escherichia coli bacteria evolve within
the body over time and across different bodily regions. DNA analysis revealed that while the
bacteria adapt swiftly to their host environment initially, they undergo minimal genetic changes
thereafter, remaining detectable in patients for up to nine years.
Implications for Treatment and Transmission
Lead author Dr. Lisandra Aguilar Bultet emphasizes the significance of these findings in guiding
treatment decisions. Patients carrying resistant bacteria not only experience recurrent infections
themselves but also serve as potential reservoirs for transmitting these pathogens to others. The
study underscores the importance of selecting appropriate antibiotic treatments, considering the

2. risk of treatment failure due to bacterial resistance. Moreover, the identification of shared genetic
mechanisms of resistance among bacterial strains within and between species highlights the
potential for horizontal gene transfer, complicating efforts to contain antibiotic resistance.
Overall, the study underscores the urgency of addressing antibiotic resistance and the need for
tailored treatment strategies. The findings provide valuable insights into the persistence and
transmission of resistant bacteria within the human body, informing future research efforts aimed
at mitigating the impact of antibiotic-resistant infections.