All are true regarding pseudomonas aeruginosa, except:
**Core Concept**
Pseudomonas aeruginosa is a gram-negative, opportunistic pathogen known for its virulence and resistance to multiple antibiotics. It is commonly found in water and soil environments, and can cause a range of infections in humans, particularly in immunocompromised individuals.
**Why the Correct Answer is Right**
The correct answer is one of the options that accurately describes a characteristic of Pseudomonas aeruginosa. This bacterium is known for its ability to produce a biofilm, which is a complex community of microorganisms that adhere to a surface and are resistant to antibiotics and host immune responses. Pseudomonas aeruginosa also produces a number of virulence factors, including elastase, alkaline protease, and exotoxin A, which contribute to its pathogenicity.
**Why Each Wrong Option is Incorrect**
**Option A:** Pseudomonas aeruginosa is a gram-positive bacterium. This is incorrect because Pseudomonas aeruginosa is actually a gram-negative bacterium.
**Option B:** Pseudomonas aeruginosa is typically a pathogen of the skin and soft tissues. This is incorrect because while Pseudomonas aeruginosa can cause skin and soft tissue infections, it is also a common cause of respiratory tract infections, particularly in individuals with cystic fibrosis.
**Option C:** Pseudomonas aeruginosa is susceptible to all beta-lactam antibiotics. This is incorrect because Pseudomonas aeruginosa is often resistant to beta-lactam antibiotics, including carbapenems, due to the production of beta-lactamases.
**Clinical Pearl / High-Yield Fact**
One high-yield fact to remember is that Pseudomonas aeruginosa is often resistant to multiple antibiotics, including carbapenems, and requires specialized treatment regimens. This is due to its ability to produce beta-lactamases and other virulence factors that contribute to its antibiotic resistance.
**Correct Answer:** D.