5 Things You Should Know About Disease Carrying Bacteria Around You
Pathogens—such as streptococci and staphylococci—are everywhere around us. But they don’t always make us sick. When are they harmless? And when do they become dangerous? Find out in this explainer, produced in collaboration with microbiologist Clare Kirkpatrick.
1: They don't mean you any harm
Like all other living organisms on Earth, they are only interested in meeting their own needs and leading a stress‑free existence.
2: They hate sunshine
Sunlight is one of the best natural disinfectants. UV light damages bacterial DNA, which is why it is used to disinfect frequently touched surfaces in hospital rooms. Due to the UV radiation in sunlight, it is very difficult for pathogens to survive in environments exposed to direct sunlight.
These often make us sick
- E. coli (e.g. diarrhea and urinary tract infections)
- Chlamydia (can lead to infertility)
- Campylobacter (e.g. gastrointestinal infection)
- Salmonella (diarrhea and fever)
- Pneumococci (e.g. pneumonia and middle ear infection)
Source: Statens Serum Institut.
3: Suddenly they go from harmless to dangerous
Pathogens are everywhere, but they only cause harm if they end up in the wrong place at the wrong time. For example:
- E. coli is generally harmless in our intestines, where it helps keep other, more dangerous bacteria in check. But if E. coli finds its way into the urinary tract or the bloodstream, it can cause urinary tract infections or blood poisoning (sepsis).
- Staphylococci can live peacefully on the skin and in the nose but become dangerous if they enter an open wound.
- Streptococcus pneumoniae can also live harmlessly in the nose and throat but may infect lungs or middle ear if it migrates. If it reaches the bloodstream or the meninges, there is a risk of meningitis.
4: Your skin is your shield
Give your skin some extra appreciation—it does tremendous work to prevent pathogens from entering your body. The skin is an effective barrier, which means that most pathogens must come into contact with an open wound, an eye, the nose, or the mouth in order to enter the body and pose a threat.
5: They have natural enemies - and one of them is called a phage
Antibiotic‑resistant bacteria are a major problem. That is why researchers are working to develop new antibiotics or entirely different approaches to combat them. At SDU, research is being conducted on bacteriophages—viruses that specifically attack bacteria. Phages are found everywhere and many are likely just waiting to be discovered and put to use. For example, Clare Kirkpatrick and her students found one in the Odense River that turned out to be able to attack and kill the resistant Pseudomonas aeruginosa found in hospitals.
Meet the researcher
Clare Kirkpatrick is a microbiologist and Associate Professor at Department of Biochemistry and Molecular Biology. Her group studies bacterial stress response, particularly DNA damage stress, cell envelope stress and bacteriophage attack.
