All of these are virulence factors that allow helicobacter pylori to colonize the stomach except

I believe the answer for the above question is Hemolysins. 
Helicobacter pylori is a bacterium that causes chronic inflammation in the stomach and duodenum and is the common cause of the chronic inflammation in the stomach. It causes chronic inflammation (gastritis) by invading the lining of the stomach and producing a cytotoxin; vacuolating cytotoxin A, and therefore, can lead to formation of ulcer.

Aneutral atom must have the same number of neutrons and protons? no, they must have the same number of protons and electrons