Pseudomonas is a Gram-negative, rod-shaped bacterium commonly found in soil, water, plants, animals and humans that has evolved to become a potentially virulent nosocomial pathogen. It is the most common bacteria isolated from patients who have been hospitalised longer than one week and is a frequent cause of hospital-acquired urinary tract infections, bacteraemia and pneumonia. It is becoming increasingly resistant to antibiotics, particularly the species Pseudomonas aeruginosa.
Who Is Susceptible
Like most hospital-acquired infections, Pseudomonas exploits vulnerable hosts. However, it is more insidious than most and will invade practically any tissue. But, it almost never invades tissues that are not compromised. It seeks out severe burns, cancer and AIDS, and anyone who is immunocompromised in any way. It thrives in moist environments and rarely grows on dry skin. These preferences converge to cause urinary tract infections by invading catheters, respiratory systems infections in those on ventilators, dermatitis, soft-tissue infections, bone and joint infections in post-surgical patients with fractures, gastrointestinal infections and general systems infections.
Signs and Symptoms of Colonization
Colonisation is a term used to describe the presence of organisms in, or on, the body that are not currently causing illness. They may be a part of the body's normal flora, or the immune system is keeping them in check. There are few or no outward signs or symptoms of Pseudomonas colonisation in healthy individuals. Because there are no signs, those at greatest risk of infection are tested for the bacteria and put on prophylactic antibiotics, particularly those with cystic fibrosis. Once infection occurs, Pseudomonas is difficult to eradicate and frequently leads to progressive lung damage. Its intractable nature is so severe that some cystic fibrosis patients may be given a vaccine.
Signs and Symptoms of Infection
Infection denotes the presence of an organism that is causing an illness. Signs and symptoms of Pseudomonas infection vary depending upon the site, but it often has a characteristic sweet smell and, like all infection, produces fever. Lung invasion and the subsequent pneumonia it causes is common in the immunocompromised, those on ventilators and persons with chronic lung disease. Severe shortness of breath, a worsening productive cough, fever, chills and confusion are its hallmarks. Endocarditis presents with fever, malaise and a heart murmur, while cellulitis and hypothermia can be signs of Pseudomonas invasion of the tissues, particularly in burn victims. Gastrointestinal presence causes urinary tract infections and diarrhoea and can lead to meningitis. Lingering post-operative bone and joint pain can signal Pseudomonas infection of the skeletal region.
Antibiotics, oral or intravenous, are the typical course of treatment. Type and duration vary and depend upon the infection site and severity.
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