Final answer:
Pseudomonas aeruginosa is an aerobic, gram-negative, antibiotic-resistant bacterium that produces virulence factors and forms biofilms, making it a successful opportunistic pathogen in people with compromised health.
Step-by-step explanation:
Pseudomonas aeruginosa as an Opportunistic Pathogen
Pseudomonas aeruginosa is a highly successful opportunistic pathogen that can cause a variety of infections, particularly in individuals with compromised health, such as patients with cystic fibrosis or those assisted with artificial ventilators. It is characterized as an aerobic, gram-negative bacterium that cannot grow in the absence of oxygen and has a high metabolic capacity due to its large genome. Pseudomonas aeruginosa is known for its ability to produce a variety of virulence factors, such as exotoxins, alginate, and siderophores like pyocyanin and pyoverdin, which enhance its ability to infect and survive in low-iron environments. Its antibiotic resistance and the production of protective biofilms make it particularly tough to treat when it causes infections in wounds, the respiratory system, or the skin. Additionally, it can remain viable on surfaces, such as hospital sinks, for extended periods, which contributes to its role in hospital-acquired, or nosocomial, infections.
Patients with cystic fibrosis are especially vulnerable to lung infections caused by P. aeruginosa because the genetic defect in the cystic fibrosis transmembrane receptor leads to the accumulation of thick mucus, which impairs lung defenses and allows the bacterium to establish persistent infections. These infections are difficult to treat and often result in chronic lung inflammation, leading to severe complications and mortality. To diagnose infections caused by P. aeruginosa, cetrimide agar can be used to selectively identify the presence of this bacterium.