Multidrug resistant Pseudomonas aeruginosa

Multidrug resistant Pseudomonas aeruginosa

Also known as: MDR Pseudomonas aeruginosa

Industry of interest: Healthcare

Classification: Bacteria

Microbiology: P. aeruginosa is a Gram-negative opportunistic pathogen that is commonly associated with hospital-acquired infections (HCAIs). The definition of multidrug resistance in P. aeruginosa is currently under debate but is generally considered to be resistance to at least 3 classes of currently available antimicrobials (Wang et al., 2006).

Make an enquiry

> Larger preview


Habitat and transmission: P. aeruginosa forms part of the normal human flora and can also be found in soil and in water. P. aeruginosa survives readily in the environment and can spread by person-to-person contact or when medical devices such as catheters are inserted. MDR P. aeruginosa strains can arise from an endogenous source if the person has been treated recently with antimicrobials or can be acquired from other sources. It is thought that MDR P. aeruginosa strains may lose some of their fitness as a consequence of increased antibiotic resistance and therefore cannot survive as readily in the environment as antibiotic susceptible strains.

Treatment and resistance: P. aeruginosa is intrinsically resistant to many drugs (Wang et al., 2006). However, prolonged antibiotic use, particularly in intensive care units (ICUs), can lead to P. aeruginosa gaining multidrug-resistance (Wang et al., 2006). P. aeruginosa use different strategies to aid their drug resistance, including efflux systems, enzyme production (for example, extended- spectrum β-lactamases; ESBLs), porin loss and target mutations (Hirsch and Tam, 2010). This broad-spectrum antimicrobial resistance restricts the therapeutic options available. Last resort antibiotics tend to include aminoglycosides and polymyxins (Hirsch and Tam, 2010).

Prevention and control: Due to the increase in MDR and even potentially pandrug-resistant (PDR) strains of P. aeruginosa and the adverse side effects associated with last line drugs, there is a need to find new and effective antimicrobial treatments (Hirsch and Tam, 2010). Importance should still be placed on standard infection control procedures such as hand-hygiene, aseptic insertion of medical devices, isolation and use of contact precautions, enhanced environmental decontamination, surveillance of MDR strains and controlled use of antimicrobials agents within hospitals. Screening is usually only performed for MDR-P. aeruginosa during outbreaks.


Disease and symptoms: MDR P. aeruginosa strains are one of the main causes of drug-resistant HAIs. MDR P. aeruginosa is responsible for infections such as pneumonia, urinary tract infections (UTIs) and bacteraemia. MDR strains are a significant cause of morbidity and mortality (Wang et al., 2006). MDR P. aeruginosa infections are particularly problematic in cystic fibrosis patients, those with coronary obstructive pulmonary disease (COPD), burns patients, cancer patients, immunocompromised individuals and patients who have recently had medical devices implanted. Particular risk factors for acquisition of MDR strains include mechanical ventilation, nasogastric feeding, catherterisation, “bed-ridden” conditions and prolonged hospital stays (Wang et al., 2006).


Hirsch E.B. and Tam V.H. (2010)
Impact of multidrug-resistant Pseudomonas aeruginosa infection on patient outcomes. Expert Rev Pharmacoecon Outcomes. 10(4): 441-451.

Wang C.Y., Jerng J.S., Cheng K.Y., Lee L.N., Yu C.J., Hsueh P.R. and Yang P.C. (2006) Pandrug-resistant Pseudomonas aeruginosa among hospitalised patients: clinical features, risk-factors and outcomes. Clin Microbiol Infect. 12(1): 63-68.


Cookies on the Bioquell website

The Bioquell website uses cookies. By continuing to browse the site you are agreeing to our use of cookies. For more details about cookies and how to manage them, see our cookie policy.