In San Francisco, ten animal health care technicians developed pneumonia 2 weeks after 130 goats were moved to the animal shelter where they worked. Which of the following is false?
a. Diagnosis is made by a blood agar culture of sputum.
b. The cause is Coxiella burnetii.
c. The bacteria produce endospores.
d. The disease was transmitted by aerosols.
e. Diagnosis is made by complement-fixation tests for antibodies.

Verified step by step guidance

1. Step 1: Identify the organism associated with the symptoms and context. In this case, the organism is Coxiella burnetii, which is known to cause Q fever, often linked to livestock such as goats.
2. Step 2: Review the characteristics of Coxiella burnetii. It is a small, obligate intracellular bacterium that does not grow on standard blood agar plates, which is important for diagnostic methods.
3. Step 3: Consider the transmission method. Coxiella burnetii is typically transmitted via aerosols, especially from infected animals, which aligns with the scenario of animal health care technicians developing pneumonia.
4. Step 4: Evaluate the diagnostic methods. Coxiella burnetii is not typically diagnosed using blood agar culture of sputum, but rather through serological tests such as complement-fixation tests to detect antibodies.
5. Step 5: Analyze the statement about endospores. Coxiella burnetii does not produce endospores; instead, it forms a spore-like structure that is resistant to environmental stresses, which is a key point in determining the false statement.

Key Concepts

Coxiella burnetii

Coxiella burnetii is a gram-negative bacterium that causes Q fever, primarily affecting livestock and humans. It is known for its ability to survive in harsh environments and can be transmitted through aerosols, particularly from infected animals or contaminated environments. Understanding its transmission and pathogenicity is crucial for diagnosing related pneumonia cases.

Diagnosis of Pneumonia

Diagnosis of pneumonia can involve various methods, including blood agar cultures of sputum and serological tests like complement-fixation tests for antibodies. Blood agar cultures help identify the causative organisms, while serological tests detect immune responses to infections. Knowing these diagnostic methods is essential for determining the correct approach to pneumonia cases.

Endospores

Endospores are highly resistant structures formed by certain bacteria, allowing them to survive extreme conditions. However, Coxiella burnetii does not produce endospores; instead, it exists in a metabolically inactive form called a small cell variant. Recognizing the characteristics of the bacteria involved in pneumonia is vital for accurate diagnosis and treatment.