The genes vanA, vanB, and vanC confer resistance to which antibiotic?

The genes vanA, vanB, and vanC are part of a group of genes that encode for vancomycin resistance, primarily in certain types of bacteria such as Enterococcus faecium and Enterococcus faecalis. These genes alter the target site for vancomycin, which is an antibiotic commonly used to treat serious bacterial infections, especially those caused by Gram-positive organisms that are resistant to other antibiotics.

When these genes are present, the structural components of the bacterial cell wall, specifically the peptide moieties that vancomycin binds to, are modified, making the antibiotic ineffective. Consequently, the correct answer is linked to the mechanism through which these genes confer resistance, making vancomycin the antibiotic that this resistance applies to.

The other choices listed pertain to different antibiotics that are not directly associated with the van genes; therefore, they do not provide the context of resistance that is fundamental to this question.