Pseudomonas - friend and foe

Posted on January 22, 2019   by Matt Bassett

Species within the genus Pseudomonas are amongst the most researched bacteria in the scientific community. Bacteria in this genus are widely used as model organisms in microbial research, and include a range of important species in fields such as plant pathogenicity, bioremediation, and environmental microbiology.

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Opportunistic Pathogens

Healthy individuals rarely contract Pseudomonas infections. The bacteria are known as opportunistic pathogens, meaning they will only cause an infection when the host has a weakened immune system, for example, from HIV or cystic fibrosis – a genetic disorder that affects the lungs’ ability to clear out bacteria and dust particles. Due to the high concentration of potential hosts, hospitals are common places for Pseudomonas infections to spread.

Perhaps one of the most well-known species in the Pseudomonas genus is Pseudomonas aeruginosa. This particular species thrives on moist surfaces and is often found on and in medical equipment, such as catheters, so spreads easily in hospital environments. Due to the host usually having pre-existing conditions, the inflammation and potential sepsis caused by infection can be fatal. P. aeruginosa is of particular concern to scientists due to its low susceptibility to antibiotics, and has been labelled as critical by the WHO on their list of antibiotic-resistant priority pathogens.


Some bacterial species have the ability to come together in large numbers to form biofilms. The bacteria within the biofilm stick together by secreting a slimy substance made of extracellular polymeric substances (EPS). Biofilms are particularly worrying, as the bacteria within the biofilm are protected from antibiotics and the body’s immune system.

One of the contributing factors to Pseudomonas’ success is their ability to form biofilms. The increased protection given by the biofilm can be particularly worrying to those with cystic fibrosis, as it can lead to chronic infections and inflammation, damaging the lung tissue.

Not all bad

Whilst Pseudomonas species are causing problems, they also have immense potential. Bioremediation is the breaking down of harmful substances, for example oil, into less harmful substances. Due to their metabolic diversity and built in resistance to chemicals present, Pseudomonas have huge potential to aid in man-made disasters, such as oil spills. Pseudomonas are also of huge importance in the agriculture industry; when applied to plants and soils they act as biocontrol agents, promoting plant growth by preventing pathogens from establishing and reducing crop yield.

Call for Research

Research into Pseudomonas is of vital importance, not just due to the danger they pose in regards to antimicrobial resistance, but because they have the potential to help in fields such as crop security and environmental sustainability.

The 17th International Conference on Pseudomonas is a biennial event that brings together researchers from all over the world who are working on the genus Pseudomonas. In conjunction with the International Conference on Pseudomonas, the Journal of Medical Microbiology has launched a Pseudomonas collection, bringing together original articles, mini-reviews and full-length reviews, focusing on all aspects of Pseudomonas research.

If you would like to submit your research article to the collection you can do so on the Journal of Medical Microbiology website (please state that you are submitting to the Pseudomonas collection in your cover letter).