Peezy vs. Clean Catch in Asymptomatic Bacteriuria Screening for Pregnant Women

Objectives: Asymptomatic bacteriuria (ASB), if left untreated, can cause significant morbidity in pregnant women. Although ASB screening is recommended, methods for collection and screening remain unstandardized. Contamination of midstream urine collections with vaginal flora can complicate interpretation and confound ASB diagnosis. Previous studies show urine samples assessed by the standard urine culture (SUC) method miss half of known uropathogens compared with the expanded quantitative urine culture (EQUC) protocol. We aim to examine the difference in the urobiome detected by SUC versus EQUC in midstream voided urines obtained with the Peezy device, which provides standardization of midstream urine collection, or the standard “clean catch” method.

Methods: This randomized controlled trial enrolled adult English-speaking women without preexisting genitourinary disease or currently taking antibiotics, presenting for their initial obstetric care visit ( < 20-week gestation) from August 2021 to November 2023. Participants were randomized to using Peezy or the clean catch method for ASB screening and received corresponding verbal instructions. Aliquots of voided urine were sent to the lab for EQUC and SUC. SUC was performed by inoculating 0.001 ml of urine onto MacConkey agar and a 5% sheep blood agar plate (BAP). These were incubated aerobically at 37°C for 24h. EQUC was performed by inoculating 0.01 ml of urine onto chocolate, colistin nalidixic acid (CNA), and anaerobe 5% sheep blood agars plus 2 BAP. One BAP, chocolate, and CNA plate were incubated in 5% CO2 at 37°C for 48h. One BAP was cultured aerobically, and the anaerobic plate was cultured anaerobically, both at 37°C for 48h. Matrix-assisted laser desorption ionization–time of flight mass spectrometry identified the bacterial species. Descriptive statistics and multidimensional scaling were performed.

Results: 98 women enrolled: 50 in the Peezy group and 48 in the standard group (Table 1). The mean gestational ages of participants at enrollment were 11.4 weeks (IQR: 8.6-13.4) and 9.7 weeks (IQR: 7.2-11.8) for Peezy and standard group, respectively. 40% of standard group had a BMI of 30kg/m,2 while 46% of Peezy group had a BMI of 30kg/m2. Between Peezy and standard collection methods, we observed no obvious difference in taxa detected (Figure 1A). Meanwhile, we observed a clear difference in urobiome characterization between SUC and EQUC using multidimensional scaling (Figure 1B). Furthermore, participants with BMI 30kg/m2were characterized by greater prevalence of Brevibacterium (p=0.0090, adjusted-p=0.40) and Corynebacterium (p=0.017, adjusted-p=0.40), while more Gardnerella (p=0.055, adjusted-p=0.74), Staphylococcus (p=0.067, adjusted-p=0.74), and Candida (p=0.080, adjusted-p=0.74) were associated with participants with BMI < 30kg/m2 (Figure 1A).

Conclusions: Overall, there were no observable differences in taxa between the Peezy and standard collection methods. However, clear differences exist between paired SUC and EQUC culture data for each participant. Taxa specificity also was associated with BMI index.