The character of Sheldon Cooper was inspired by a computer programmer personally known to series co-creator Bill Prady. He is named in honor of actor/producer Sheldon Leonard and Nobel Prize Laureate Leon Cooper.
The infection is caused by bacteria. However, excessive use may irritate you. Soda also dehydrates you, and for proper urinary health you should be drinking lots of water, and also cranberry juice. Your physician was definitely right in telling you that it could have made the bladder infection worse.
Nitrates are a form of nitrogen, consumed in food additives and derived from protein metabolism. The presence of nitrates in the urine is generally considered normal. However, certain bacteria that are frequently the cause of urinary tract infection produce an enzyme that changes urinary nitrates to nitrites. Therefore, the presence of nitrites in the urine is an indirect indication of urinary tract infection. It's possible to have an infection without nitrites in the urine. The only bacteria that change nitrates to nitrites are Escherichia Coli (E. Coli), Klebsiella and Proteus. Other organisms that can cause urinary tract infection which do not cause nitrates to be converted to nitrites include Pseudomonas and enterococci.