Study led by the University of Coimbra suggests a paradigm shift in the treatment of staph infections
S. aureus is a bacterium commonly found on the skin and in nasal cavities of healthy people.
English version: Diana Taborda
A new study led by scientists from the Centre for Neuroscience and Cell Biology of the University of Coimbra (CNC-UC), now published in the scientific journal Nature Communications, reveals that the Staphylococcus aureus (S. aureus) bacterium has a predominant intracellular lifestyle (inside the host cell), which may justify changing the clinical criteria for choosing antibiotics against this bacterium.
S. aureus is a bacterium often found on the skin and in the nasal cavities of healthy people. However, it may cause diseases ranging from simple skin infections (abscesses, cellulitis) to more serious infections such as pneumonia, endocarditis, bacteraemia (infection in the blood), among others.
Multibiotic-resistant bacteria are increasingly common, which seriously complicates the treatment of bacterial infections. S. aureus shows resistance to several antibiotics and is currently the second most common cause of death associated with antimicrobial resistance worldwide and the first in Portugal.
The study presents a large-scale analysis of 191 clinical isolates of S. aureus from patients with osteomyelitis (bone infection), infectious arthritis, bacteraemia and endocarditis, and their interaction with various host cell types (target cells of the bacterium) over time. This study reveals “that although S. aureus is commonly described as an extracellular pathogen, almost all clinical isolates of S. aureus tested in this study (over 98%) were internalised by various host cell types in a laboratory setting. It was further proven that a large part of these isolates have the ability to replicate and persist within host cells”, explains Miguel Mano, one of the study leaders, (researcher at CNC-UC and professor at the Department of Life Sciences of the Faculty of Sciences and Technology of the University of Coimbra - FCTUC).
The results of this work support the need for a paradigm shift in the treatment of S. aureus infections. "The therapy chosen to effectively eliminate this pathogen should consider not only its antibiotics susceptibility profile, as is currently done, but also the different intracellular lifestyle of S. aureus. The chosen therapy should ensure its elimination within the cells, since the lack of intracellular effect of antibiotics may lead to treatment failure, resulting in recurrent and/or chronic infections", explains the leader of the study, Ana Eulálio (researcher at CNC-UC and iBiMED, University of Aveiro).
This research work was carried out in collaboration with researchers from the International Centre for Infectiology Research (CIRI) (Lyon, France), the National Reference Centre for Staphylococci, Institute of Infectious Agents (Lyon, France) and the Biotechnology Centre, Spanish National Research Council (CNB-CSIC). It received funding from the Foundation for Science and Technology (FCT), the ERA-NET Infect-ERA Consortium and the European Horizon 2020 Marie Sklodowska-Curie.