Abstract:

Objective To study the role of Corynebacterium urealyticum in the formation of ammonium magnesium phosphate crystals in urine,and to provide a reference for the prevention of urinary calculi. Methods Urine samples with ammonium magnesium phosphate crystals were collected from the First Affiliated Hospital of Hebei North University from January 2015 to December 2016, Corynebacterium urealyticum was cultured in the fresh urine without bacteria and other urine formed elements. After culturing for 24 and 48 h,the formation of ammonium magnesium phosphate crystals was observed by ultrahigh sensitive microscope. Results Bacteria in urine samples of 17 males and 8 females were isolated in 46 cases of urine samples with ammonium magnesium phosphate crystals, and 12 cases had 2 pathogens. There were 8 isolates of Corynebacterium urealyticum,the positive rate was 32.0%（8/25）,and there were 7 isolates from males. There were 8 isolates of Enterococcus,6 isolates of Proteus mirabilis,5 isolates of Escherichia coli,3 isolates of Klebsiella pneumoniae,3 isolates of Candida albicans and 2 isolates of Pseudomonas aeruginosa. There were 4 of 8 isolates of Corynebacterium urealyticum mixed with other pathogens. Ammonium magnesium phosphate crystals were observed from urine culture fluid. Most of the crystals formed were unformed feather crystals, followed by cubic, square cylinder and envelope-like crystals. Conclusions Corynebacterium urealyticum is one of the main pathogens of urinary tract infection and urinary calculus formation for specific population.

Key words: Corynebacterium urealyticum, Ammonium magnesium phosphate crystal, Urinary tract infection