True or False: Fastidious organisms can cause pneumonia.

Fastidious organisms are those that have complex nutritional requirements and often do not grow easily on standard culture media. Despite their demanding growth conditions, these organisms can indeed cause pneumonia. This is particularly relevant in clinical microbiology, where certain fastidious bacteria can lead to respiratory infections, especially in individuals with specific risk factors.

For instance, organisms such as Legionella pneumophila and Haemophilus influenzae are recognized as fastidious and can be responsible for pneumonia. Legionella is known to cause a specific type of pneumonia called Legionnaires' disease, which is often associated with outbreaks. Similarly, H. influenzae can lead to pneumonia, especially in certain patient populations.

The other choices suggest limitations about when fastidious organisms can cause pneumonia. While it's true that some patients, such as those with compromised immune systems or underlying health challenges, are at greater risk of infection from these organisms, it is not accurate to state that fastidious organisms are limited to only these groups; they can affect a broader population.

Therefore, stating that fastidious organisms can cause pneumonia is correct, highlighting their role in infectious diseases.