First trimester "clean catch" urine and vaginal swab sample distinct microbiological niches.

IMPORTANCE: Untreated asymptomatic bacteriuria (ASB) has been associated with adverse pregnancy outcomes, including pyelonephritis, preterm labor, and low birth weight infants. Thus, routine screening by standard urine culture (SUC) and treatment of ASB are currently recommended for all pregnant women. For this purpose, some researchers claim that vaginal swabs and urine samples can be used as proxies for each other. Because SUC often misses microbes, we used two more sensitive, recently validated detection methods to compare the composition of the urinary and vaginal microbiomes of pregnant females in their first trimester. Both methods yielded similar results. Vaginal and urinary microbial compositions for the same individual were significantly correlated; however, they were not equivalent. We argue that first trimester urinary and vaginal microbiomes are distinct enough to preclude their use as proxies for each other.

Urogenital urobiome of healthy children does not differ from that of children with bladder and bowel dysfunction.

INTRODUCTION: The pediatric urinary microbiome (urobiome) has been studied in the context of healthy children and children with genitourinary pathologies including neuropathic bladder, urinary tract infection (UTI) and nephrolithiasis. Little is known about the urobiome of children with bladder and bowel dysfunction (BBD), a condition that is an established risk factor of UTI. We hypothesized that the symptoms of a child with BBD may be related to urobiome composition. OBJECTIVE: To evaluate the urogenital urobiome's role in BBD, we compared the urogenital urobiomes of children with and without BBD. STUDY DESIGN: We performed a prospective case-control pilot study at a single large, academic children's hospital. Cases included toilet trained prepubertal females over 2 years of age with BBD established through a validated scoring system and controls included asymptomatic, presumably healthy, children. Children were excluded if they had symptoms or lab work consistent with a concurrent UTI or antibiotic course for any reason within the prior 14 days. We performed 16 S ribosomal RNA gene sequencing and expanded quantitative urine culture on clean catch urine samples. To compare within sample (alpha) diversity, we used the Kruskal-Wallis test. To compare between sample (beta) diversity, we calculated the Bray-Curtis distance and performed the PERMANOVA test. RESULTS: Data from 25 children with BBD and 8 asymptomatic controls were analyzed. The demographic and clinical characteristics of the two comparison groups were similar, though a higher proportion of Black children were included in the asymptomatic control group. Neither alpha diversity nor beta diversity was significantly different between the two groups. The core microbiome of the BBD group included all the genera in the core urogenital urobiome of the controls, plus additional genera associated with opportunistic infection and/or UTI, including Escherichia, Campylobacter and Streptococcus. DISCUSSION: The results of both the 16 S sequencing and expanded quantitative urine culture in this small study suggest that the urogenital urobiomes of children with BBD do not differ significantly from those of asymptomatic children. However, the core urogenital urobiome of children with BBD included genera associated with opportunistic infection and/or UTI. This study was limited by the sample collection method ("clean catch" midstream voided urine samples, which introduce the possibility of vulvovaginal contamination), small sample size, and unequal balance of patient characteristics between the two study groups. CONCLUSION: The urogenital urobiomes of children with and without BBD do not appear to significantly differ. Larger studies are needed to confirm these findings.

A Child's urine is not sterile: A pilot study evaluating the Pediatric Urinary Microbiome.

INTRODUCTION: A bladder microbiome (urobiome) exists in adults. Data supports the effects of the adult urobiome on urinary tract health with associations between dysbiotic urobiomes and lower urinary tract disorders. Understanding urobiome origin is important since other microbiomes establish around birth and microbiome alterations are linked to disease development. However, the pediatric urobiome has not been well studied. OBJECTIVES: We sought to determine the age when the urobiome develops, compare the pediatric urobiome to microbiomes of adjacent urogenital niches, and compare the urobiomes between boys and girls and across age groups. STUDY DESIGN: Seventy-four children less than 18 years of age without recent antibiotic exposure were recruited, including 48 males and 26 females, aged 2 weeks to 209 months of age. Transurethral catheterized urine samples and samples from the perineum, urethra, vagina, and foreskin were collected. Specimens were assessed using the expanded quantitative urine culture protocol and by 16S rRNA gene sequencing. Dada2 was used to profile microbial compositions, and BLCA was used to identify microbial taxa. RESULTS: Bacteria were detected in 90.5% of urine samples and identified in children as young as 2 weeks of age. Microbial communities and compositions of the female bladder and other urogenital niches (urethra, perineum, and vagina) differed significantly by age. Lactobacillus predominated the bladder, urethral, and vaginal microbiomes in post-pubertal girls. Compared to female urinary microbiomes, those of males differed less substantially. Only perineal microbiomes differed significantly by age, whereas male urethral and foreskin microbiomes did not differ significantly. DISCUSSION: We identified that a urinary microbiome is established as early as infancy. In addition, the female urobiome changes throughout childhood, until the post-pubertal bacterial taxa becomes consistent with that seen in adult females. Whereas in boys, the urinary microbiome changed very little over time. In addition, the surrounding urogenital microbiomes differed less in boys as compared to females. Microbiomes established at a young age may have long-term influences on immune, metabolic, and neurobehavioral traits. The same may be true for the urobiome. Our study provides a foundation for future research to determine the influence of the pediatric urobiome on the development of urinary and even non-urinary disorders. CONCLUSIONS: A pediatric urobiome exists, with differences between males and females and can be detected at a young age with changes occurring throughout childhood. Similarities and differences are also seen between the pediatric urobiome and adjacent niches.