Final answer:
Nontreponemal antibodies, such as VDRL and RPR, are tested for first in patients believed to have syphilis. If these tests come back positive, further testing with treponemal serologic tests can be done to confirm the presence of specific antibodies against the syphilis bacterium.
Step-by-step explanation:
In patients believed to have syphilis, the type of antibodies that are tested for first are nontreponemal antibodies. These include the Venereal Disease Research Laboratory (VDRL) and rapid plasma reagin (RPR) tests. These tests detect nonspecific antibodies produced during syphilis infection. If these tests come back positive, further testing with treponemal serologic tests can be done to confirm the presence of specific antibodies against the syphilis bacterium.