Urinary tract infection due to a mucoid (M) form of Salmonella. A "new" transformation from M form into T1 form.

An eighty-year-old patient suffering from prostatic hypertrophy developed cystitis associated with fever, macrohematuria and significant bacteriuria. In urine cultures, growth of a mucoid (M) form of Salmonella was seen which changed into a T1 form after having been stored at room temperature or passed through U tubes. While the M form did not agglutinate in Salmonella O and H antisera, H antigens of the T1 form could be identified as l,v and 1.