The comic (which you can click on to get the full sized version) depicts a doctor who is giving a diagnosis to someone who believes in Creation. The patient has some form of TB, and the punch line is that the doctor says that he can treat the patient with a series of antibiotics that take into account what the strain of TB has “evolved” into, or give him the basic set that was developed earlier. It depicts the patient as wavering in his views. What it really shows is the fact that the cartoonist really doesn’t know the subject he is lampooning very well (except maybe only superficially).
Creationists, for the record, do not disagree that a specific strain of virus can become resistant to certain treatments, but disagree as to the cause. Creationists believe that the resistance is because of a loss of genetic information, not a gain. It’s not like the virus adapted, but natural selection eliminated those virii that were not immune (because of a defect) and left those that are immune. These are actually weaker virii and it’s just because their receptors are no longer there.
Creationists don’t question whether natural selection is there, but they do not believe that natural selection caused everything you see today. This is a major point. Creationists believe that speciation happened through natural selection, so what you see today is natural selection creating different species within a given kind.