Final answer:
Cystitis due to asymptomatic bacteriuria in pregnancy is caused by bacterial infection of the bladder, with gram-negative bacteria being the most common culprits. Hormonal changes during pregnancy can increase the risk of bladder infections.
Step-by-step explanation:
Cystitis due to asymptomatic bacteriuria in pregnancy is caused by bacterial infection of the bladder. The most common bacteria that cause bladder infections are gram-negative bacteria such as Escherichia coli (E.coli), Proteus vulgaris, Pseudomonas aeruginosa, and Klebsiella pneumoniae. These bacteria can enter the bladder from the lower gastrointestinal tract. In pregnancy, hormonal changes can affect the urinary tract and make pregnant women more susceptible to bladder infections.