**Question:** Mark the false statement regarding Borellia:

A. Borellia is a bacterium that causes Lyme disease in humans.
B. Borellia primarily infects red blood cells.
C. Borellia is only found in warm climates.
D. Borellia is a plant pathogen.

**Correct Answer:** **D. Borellia is a plant pathogen.**

**Core Concept:** Borellia is a genus of bacteria within the order Borreliaceae, which is known to cause Lyme disease in humans and animals. Lyme disease is caused by the bacterium Borrelia burgdorferi and is transmitted to humans through the bite of infected black-legged ticks (Ixodes scapularis) in the United States and European black-legged ticks (Ixodes ricinus) in Europe.

**Why the Correct Answer is Right:** Borellia is indeed a bacterium that can cause Lyme disease, but it is not a plant pathogen. Plant pathogens are microorganisms that infect and damage plants, whereas Borellia is a zoonotic pathogen, meaning it can cause diseases in both humans and animals.

**Why Each Wrong Option is Incorrect:**

A. While Borellia is a bacterium that causes Lyme disease, the statement about infecting red blood cells is incorrect. Borrelia burgdorferi primarily infects various tissues and organs, including the skin, joints, heart, and nervous system, rather than red blood cells.

B. The statement about Borellia primarily infecting plants is incorrect. As mentioned above, Borellia is a zoonotic pathogen, infecting animals and humans, not plants.

C. The statement about Borellia being restricted to warm climates is incorrect. Lyme disease can occur in various climates, including cooler regions. However, the bacterium is more prevalent in areas with dense forests and tall grass, where ticks thrive.

**Clinical Pearl:** Lyme disease is a significant public health concern, with an estimated 300,000 to 1 million cases annually in the United States alone. Early symptoms include a characteristic skin rash (erythema migrans) and flu-like symptoms, followed by joint pain, fever, and fatigue. If left untreated, Lyme disease can cause more severe complications like heart arrhythmias, neurological disorders, and arthritis. Prompt diagnosis and treatment are crucial to prevent long-term complications.