If a person has diabetes (t2), which is not particularly well controlled, then is it the case that the person is more likely to get an infection or more likely not to be able to resist the infection once he/she has it, or both?

Yes: Poorly controlled Diabetes, therefore high sugars, can affect the immune system negatively and with it the ability to combat infections.

Yes and Yes!: Diabetes, either Type 1 or Type 2, is an autoimmune disease. When it is well-controlled, your immune system works normally. When it is not well-controlled, the immune system suffers and becomes inefficient. This increases the risk of getting infections AND once you get an infection, reduces your ability to fight the infection. So, keep your A1C test # under 7.0 to stay well-controlled & healthy!