Characterization of the urogenital microbiome in Miniature Schnauzers with and without calcium oxalate urolithiasis

Abstract

Background: Calcium oxalate (CaOx) uroliths are common in dogs. Humans with CaOx urolithiasis exhibit alterations of the urinary and urogenital microbiomes that might mediate urolith formation. Detection of urogenital microbes associated with CaOx in dogs could inform disease pathophysiology. Objective: To identify compositional differences in the urogenital microbiome of Miniature Schnauzers with and without CaOx uroliths. Animals: Nineteen midstream, voided urine samples from Miniature Schnauzers with (n = 9) and without (n = 10) a history of CaOx urolithiasis. Methods: Analytical cross-sectional study. Microbial DNA was extracted from previously frozen urine samples and sequenced for the bacterial 16S rRNA V3-V4 hypervariable regions. Diversity and composition of microbial populations were compared between urolith formers and controls. Results: Alpha and beta diversity measures were similar between groups. Five individual bacterial taxa differed in abundance (indicator values >0.5 and P < .05):Acinetobacter, 2 Geobacillus variants, and Hydrogenophaga were overrepresented in the urine of urolith formers, and Sphingopyxis was overrepresented in controls. Two distinct subtypes of urine microbial composition were observed based on beta diversity measures, independent of urolith status, and other clinical variables.Conclusions and Clinical Importance: Although we did not detect a difference in the overall urogenital microbial composition between groups, observed differences in individual bacterial taxa might be clinically relevant. For example, Acinetobacter was overrepresented in urolith formers and is associated with CaOx urolithiasis in humans. Two unique clusters of the microbiome were identified, independent of urolith status, which may represent distinct urotypes present in Miniature Schnauzers.

Gut and Urinary Microbiota in Cats with Kidney Stones

“…The involvement of the intestinal and urinary microbiota in the formation of calcium oxalate stone has been studied in humans [ 22 , 31 , 32 ], in rats [ 33 , 34 , 35 , 36 , 37 , 38 ], and in dogs [ 27 , 39 ], but not in cats. We hypothesized the following: (1) that mechanisms involving the microbiota, similar to those suspected in humans, might contribute to the formation of kidney calcium oxalate stones in cats, and (2) the use of antibiotics could lead to dysbiosis and thereby increase the risk of calcium oxalate stone formation.…”

All about urine: Longitudinal examination of urine pH, specific gravity, proteins, culture, and resistance profiles in healthy dogs

“…[15][16][17][18][19] However, few studies have examined the urinary microbiota of dogs via sequencing or culture, and even fewer have evaluated change over time. 4 15,18,[20][21][22][23][24] Multiple studies have reported that dogs and humans share microbes, including urinary tract pathogens. [25][26][27][28][29][30][31][32][33] Thus, characterizing healthy canine urinary microbiota and the associated resistance profiles over time is valuable both for canine health and has implications for One Health.…”

Longitudinal examination of urine pH, specific gravity, protein, culture, and antimicrobial resistance profiles in healthy dogs

“…Urinary tract commensals are thought to play a role in host health through immune stimulation, colonization resistance, and pathogen clearance 15‐19 . However, few studies have examined the urinary microbiota of dogs via sequencing or culture, and even fewer have evaluated change over time 15,18,20‐24 . Multiple studies report that dogs and humans share microbes, including urinary tract pathogens 25‐33 .…”

“…[15][16][17][18][19] However, few studies have examined the urinary microbiota of dogs via sequencing or culture, and even fewer have evaluated change over time. 15,18,[20][21][22][23][24] Multiple studies report that dogs and humans share microbes, including urinary tract pathogens. [25][26][27][28][29][30][31][32][33] Thus, assessing the urinary microbiota of healthy dogs and the associated resistance profiles over time is valuable both for evaluating dog health and for assessing implications for human health.…”