To compare urinalysis results of women with self-reported UTI across urotypes generated from expanded quantitative urine culture (EQUC) results. We hypothesize that urinalysis results will vary relative to urotype.

This is a sub-analysis of a randomized controlled trial of women presenting to a urogynecology center with self-reported UTI symptoms who provided a catheterized urine sample and received treatment based on EQUC or standard urine culture (SUC) results. Urine samples were sent to both research and clinical microbiology labs. The research lab performed both EQUC and SUC on all samples; from EQUC results, 4 urotypes were derived: E. coli-predominant (>50% CFU/mL E. coli, EC), Gram-Negative-non-E. coli-uropathogen-predominant (>50%CFU/mL Gram-Negative non-E. coli uropathogen, GN), Gram-Positive-non-E. coli-uropathogen-predominant (>50%CFU/mL Gram-Negative non-E. coli uropathogen, GP) and culture negative (0 CFU/mL)/non-uropathogen predominant (>50% CFU/mL non-uropathogen, NUC). On all samples, the clinical microbiology lab performed urinalysis, including RBC, WBC and presence of nitrites and leukocytes; they were compared between urotypes.

Of 225 women enrolled (149 SUC; 76 EQUC), 223 had urinalysis results after the initial visit: 100 had an EC urotype, 39 a GN urotype, 37 a GP urotype, 47 were NUC. RBC & WBC counts differed significantly across urotypes (p<0.0001). The GP urotype had significantly higher WBC counts than NUC, but significantly lower median RBC and WBC counts than EC and GN (all p<0.005). Leukocyte and nitrite positivity also differed by urotype (p<0.0001). Women with both leukocyte and nitrite positivity (n=66) were more frequently in the EC or GN urotypes (94%). Women with both leukocyte and nitrite negativity (n=57) were most frequently in the NUC urotype (68%). The GP urotype was more likely to be leukocyte- and nitrite-double-negative than EC and GN urotypes, and more likely to be leukocyte-positive than the NUC urotype (all p<0.0001).

These findings suggest that there are specific urinalysis result patterns that are more frequently associated with certain microbiome culture profiles. WBC counts could be used to distinguish between between non-uropathogen/culture negative (NUC) patients and patients with predominantly E. coli (EC) or another Gram-negative uropathogen (GN). Similarly, there are clear differences in patterns of leukocyte/nitrite results between NUC and EC/GN urotypes. Patients in the GP urotype were distinct from both the NUC and EC/GN urotypes in both WBC/RBC counts and leukocyte/nitrite results.

Significant differences in leukocyte/nitrite phenotypes and WBC and RBC counts may suggest the presence of Gram-positive (GP) uropathogens that SUC frequently misses. Symptomatic patients with low non-zero WBC/RBC counts and a negative nitrite result likely possess microbes consistently detected by EQUC but often missed by SUC.