Observation of intracellular bacterial communities in urinary sediment using brightfield microscopy; a case report

Urinary tract infections (UTIs) are usually related to the presence of Escherichia coli, a microorganism that adopts an intracellular life-style during the pathogenesis of cystitis. Evidence of the underlying mechanism in urothelial cells from urine samples has been reported. However, intracellular communities have not yet been described in squamous cells in fresh samples stained with Sternheimer-Malbin method, thus, we have provided these descriptions in this case report.

Number 1 was a male patient with symptoms of UTI, his urinalysis revealed hematuria and nitrites. In the urine sediment, we found urothelial cells with internal endosomes filled with short rods. Case number 2, female patient with recurrent UTI by E. coli, her urinalysis showed positive nitrites, glycosuria, bacteriuria and squamous cells with endosomes filled with short rods. Both patients were positive for E. coli isolation.

These case reports provide evidence of the presence of intracellular bacterial communities in urothelial and squamous cells (not previously reported) in fresh urine samples stained with Sternheimer-Malbin using brightfield microscopy. The clinical impact and pathogenic mechanisms involved in the invasion of the squamous epithelium need further investigation.