Aerococcus Urinae: Establishing the Pathogenesis of an Emerging Uropathogen

Urinary tract infection (UTI) is the world\u27s most common bacterial infection. Much is known about the infectious process (pathogenesis) of a few of the bacteria that cause these infections, especially E. coli. Unfortunately, the pathogenesis of E. coli and other uropathogenic bacteria was explored almost exclusively in the belief that the bladder is supposed to be sterile. Our recent evidence, however, debunks this dogma. We used modern methods to reveal diverse bacterial communities in the bladders of adult women. These communities differ in women with and without lower urinary tract symptoms (LUTS), including UTI and urinary incontinence (UI). Many bacteria that we have detected in women with LUTS are understudied precisely because they were previously undetected or overlooked. Thus, very little is known about their pathogenesis. Aerococcus urinae is one of those understudied uropathogenic bacteria. It is associated with both UTI and UI. It is highly resistant to many antibiotics and, when undiagnosed, can cause invasive and life-threatening sepsis. Thus, I have begun a study of A. urinae\u27s pathogenesis. For well-studied uropathogens, the earliest stages of pathogenesis involve attachment to the cells that line the bladder wall (urothelium) and subsequent disruption of the host\u27s bladder immune system. I hypothesized that A. urinae also attaches to the urothelium and alters signaling to the host\u27s bladder immune system. To test my hypothesis, I first studied in vitro phenotypes of A. urinae related to attachment and colonization of the urothelium. Then, I studied the interaction between human urothelium and A. urinae strains isolated from womenwith LUTS. Results from this dissertation could be used to develop therapies that specifically target A. urinae

Characterization of the Female Urinary Microbiota and Their Association with the Female Bladder Uroepithelium

The current clinical dogma assumes that urine is sterile in the absence of clinically relevant infection. However, recent evidence has demonstrated the existence of a female urinary microbiota in women with and without lower urinary tract symptoms. With the knowledge that the lower urinary tract possesses its own unique microbiota, I hypothesize that certain bacterial species of the female microbiota may be the cause or play a role in lower urinary tract syndromes such as overactive bladder syndrome (OAB). About 40-50% of OAB patients do not respond to conventional anti-muscarinic and beta-3 adrenergic agonist drug treatment. One possible explanation for this lack of treatment response is a dysbiotic urinary microbiota. In order to determine if women with OAB have a dysbiotic urinary microbiota, an expanded quantitative urine culture (EQUC) protocol was used to culture transurethral catheter urine specimens obtained from women with and without OAB. There are differences in the female urinary microbiota in women with and without OAB. Given evidence of planktonic bacteria in the urine, I hypothesize that bacteria also may be associated with the urothelium. To examine this population, shed urothelial cells from urine were examined for the presence of adherent and/or intracellular bacteria using a new protocol. This new protocol is able to determine which bacteria associate with shed urothelial cells but cannot distinguish between adherent or intracellular bacteria. By determining the differences in urinary microbiota as well as the populations that associate with the urothelium, one can start to get a sense of how the female urinary microbiota could contribute to lower urinary tract disorders

Draft Genome Sequence for a Urinary Isolate of Nosocomiicoccus Ampullae

A draft genome sequence for a urinary isolate of Nosocomiicoccus ampullae (UMB0853) was investigated. The size of the genome was 1,578,043 bp, with an observed G+C content of 36.1%. Annotation revealed 10 rRNA sequences, 40 tRNA genes, and 1,532 protein-coding sequences. Genome coverage was 727× and consisted of 32 contigs, with an N50 of 109,831 bp

Genome Investigation of Urinary Gardnerella Strains and Their Relationship to Isolates of the Vaginal Microbiota

Gardnerella is a frequent member of the urogenital microbiota. Given the association between Gardnerella vaginalis and bacterial vaginosis (BV), significant efforts have been focused on characterizing this species in the vaginal microbiota. However, Gardnerella also is a frequent member of the urinary microbiota. In an effort to characterize the bacterial species of the urinary microbiota, we present here 10 genomes of urinary Gardnerella isolates from women with and without lower uri- nary tract symptoms. These genomes complement those of 22 urinary Gardnerella strains previously isolated and sequenced by our team. We included these genomes in a comparative genome analysis of all publicly available Gardnerella genomes, which include 33 urinary isolates, 78 vaginal isolates, and 2 other isolates. While once this genus was thought to consist of a single species, recent comparative ge- nome analyses have revealed 3 new species and an additional 9 groups within Gardnerella. Based upon our analysis, we suggest a new group for the species. We also find that distinction between these Gardnerella species/groups is possible only when considering the core or whole-genome sequence, as neither the sialidase nor vaginolysin genes are sufficient for distinguishing between species/groups despite their clinical importance. In contrast to the vaginal microbiota, we found that only five Gardnerella species/groups have been detected within the lower urinary tract. Although we found no association between a particular Gardnerella species/group(s) and urinary symptoms, further sequencing of urinary Gardnerella isolates is needed for both comprehensive taxonomic characterization and etiological classification of Gardnerella in the urinary tract. Importance Prior research into the bacterium Gardnerella vaginalis has largely focused on its association with bacterial vaginosis (BV). However, G. vaginalis is also frequently found within the urinary microbiota of women with and without lower urinary tract symptoms as well as individuals with chronic kidney disease, interstitial cystitis, and BV. This prompted our investigation into Gardnerella from the urinary microbiota and all publicly available Gardnerella genomes from the urogenital tract. Our work suggests that while some Gardnerella species can survive in both the urinary tract and vagina, others likely cannot. This study provides the foundation for future studies of Gardnerella within the urinary tract and its possible contribution to lower urinary tract symptoms

Draft Genome for a Urinary Isolate of Lactobacillus crispatus

While Lactobacillus crispatus contributes to the stability of normal vaginal microbiota, its role in urinary health remains unclear. As part of an on-going attempt to characterize the female urinary microbiota, we report the genome sequence of an L. crispatus strain isolated from a woman displaying no lower urinary tract symptoms

Genome Sequences and Annotation of Two Urinary Isolates of E. Coli

The genus Escherichia includes pathogens and commensals. Bladder infections (cystitis) result most often from colonization of the bladder by uropathogenic E. coli strains. In contrast, a poorly defined condition called asymptomatic bacteriuria results from colonization of the bladder with E. coli strains without symptoms. As part of an on-going attempt to identify and characterize the newly discovered female urinary microbiota, we report the genome sequences and annotation of two urinary isolates of E. coli: one (E78) was isolated from a female patient who self-reported cystitis; the other (E75) was isolated from a female patient who reported that she did not have symptoms of cystitis. Whereas strain E75 is most closely related to an avian extraintestinal pathogen, strain E78 is a member of a clade that includes extraintestinal strains often found in the human bladder. Both genomes are uncommonly rich in prophages

Aerococcus urinae isolated from women with lower urinary tract symptoms: In vitro aggregation and genome analysis

Aerococcus urinae is increasingly recognized as a potentially significant urinary tract bacterium. A. urinae has been isolated from urine collected from both males and females with a wide range of clinical conditions, including urinary tract infection (UTI), urgency urinary incontinence (UUI), and overactive bladder (OAB). A. urinae is of particular clinical concern because it is highly resistant to many antibiotics and, when undiagnosed, can cause invasive and life-threatening bacteremia, sepsis, or soft tissue infections. Previous genomic characterization studies have examined A. urinae strains isolated from patients experiencing UTI episodes. Here, we analyzed the genomes of A. urinae strains isolated as part of the urinary microbiome from patients with UUI or OAB. Furthermore, we report that certain A. urinae strains exhibit aggregative in vitro phenotypes, including flocking, which can be modified by various growth medium conditions. Finally, we performed in-depth genomic comparisons to identify pathways that distinguish flocking and nonflocking strains. IMPORTANCE Aerococcus urinae is a urinary bacterium of emerging clinical interest. Here, we explored the ability of 24 strains of A. urinae isolated from women with lower urinary tract symptoms to display aggregation phenotypes in vitro. We sequenced and analyzed the genomes of these A. urinae strains. We performed functional genomic analyses to determine whether the in vitro hyperflocking aggregation phenotype displayed by certain A. urinae strains was related to the presence or absence of certain pathways. Our findings demonstrate that A. urinae strains have different propensities to display aggregative properties in vitro and suggest a potential association between phylogeny and flocking

Genomes of Gardnerella Strains Reveal an Abundance of Prophages within the Bladder Microbiome

Bacterial surveys of the vaginal and bladder human microbiota have revealed an abundance of many similar bacterial taxa. As the bladder was once thought to be sterile, the complex interactions between microbes within the bladder have yet to be characterized. To initiate this process, we have begun sequencing isolates, including the clinically relevant genus Gardnerella. Herein, we present the genomic sequences of four Gardnerella strains isolated from the bladders of women with symptoms of urgency urinary incontinence; these are the first Gardnerella genomes produced from this niche. Congruent to genomic characterization of Gardnerella isolates from the reproductive tract, isolates from the bladder reveal a large pangenome, as well as evidence of high frequency horizontal gene transfer. Prophage gene sequences were found to be abundant amongst the strains isolated from the bladder, as well as amongst publicly available Gardnerella genomes from the vagina and endometrium, motivating an in depth examination of these sequences. Amongst the 39 Gardnerella strains examined here, there were more than 400 annotated prophage gene sequences that we could cluster into 95 homologous groups; 49 of these groups were unique to a single strain. While many of these prophages exhibited no sequence similarity to any lytic phage genome, estimation of the rate of phage acquisition suggests both vertical and horizontal acquisition. Furthermore, bioinformatic evidence indicates that prophage acquisition is ongoing within both vaginal and bladder Gardnerella populations. The abundance of prophage sequences within the strains examined here suggests that phages could play an important role in the species’ evolutionary history and in its interactions within the complex communities found in the female urinary and reproductive tracts