Is nature source of lyme disease?

Could say that: Nature is the source of most things. Lyme disease is caused by a bacterium transmitted by ticks. Both bacteria and ticks are natural.

Unsure what u mean: Lyme disease is caused by a spirochaete (bacteria) called borellia burgdorfii and is transmitted to man by tick bites, predominantly by the deer tick. This is part of nature.

Yes: Some ticks which exist in nature carry a bacterium which causes lyme disease inside them. When the tick bites a human, the bacterium (borelia burgdorfi) passes from the tick to the human. This infection results in lyme disease.