Since the bacterium is contagious and can be carried in the air (e.g., through coughing), its most common initial site in the body is the lungs.
(the bacterium; is; contagious) (the bacterium; can be carried; L:in the air) (its most common initial site in the body; is; the lungs)
the bacterium the bacterium its most common initial site in the body
is can be carried is
contagious
L:in the air
the lungs