Which organism is responsible for Lyme disease?

Borrelia burgdorferi is the organism responsible for Lyme disease, a tick-borne illness that occurs most commonly in certain regions of the United States and parts of Europe and Asia. This spirochete bacterium is primarily transmitted to humans through the bites of infected black-legged ticks (often referred to as deer ticks).

Once a person is infected with Borrelia burgdorferi, it can lead to various symptoms that range from early localized manifestations, such as erythema migrans (a characteristic rash), to more severe systemic issues if not treated promptly. Chronic Lyme disease can lead to symptoms affecting the joints, heart, and nervous system.

The other organisms listed do not cause Lyme disease. Escherichia coli is primarily associated with gastrointestinal infections, Streptococcus pneumoniae is a common cause of pneumonia and meningitis, and Plasmodium falciparum is a protozoan responsible for malaria. Each of these organisms is associated with distinct pathologies and transmission routes, separating them from the pathogenesis of Lyme disease caused by Borrelia burgdorferi.