Colonization Of Urinary Tract Research Articles

The evolving world of the urinary microbiome.

The existence of urinary microbiome in healthy individuals is now widely accepted as the longstanding belief in urinary tract sterility was disproved over a decade ago. The urinary microbiome has since been implicated in multiple urologic conditions including urinary tract infection (UTI), urinary incontinence, and bladder cancer. This review relays new findings of urinary microbiome compositional changes associated with aging and UTI susceptibility. Recent advancements have established how the urinary microbiome changes over the lifespan. Studies finding distinct urinary microbiomes in prepubescent, reproductive age, and postmenopausal females have identified sex hormones as potential modulators of urinary microbiome composition and have identified prevalent species that may be markers of dysbiosis. Research in male children finds a cultivable urinary microbiota that varies with age or urologic history but not delivery mode. Emerging research also addresses the function of the urinary microbiota, including genetic factors associated with urinary tract colonization and interactions with uropathogens. The urinary microbiome is a promising therapeutic target for urologic disease. However, a more functional understanding is necessary for the development of microbiome-based therapies. Future research should develop accurate animal models and explore functional relationships between the urinary microbiome and the host environment.

Gut microbiome correlates of recurrent urinary tract infection: a longitudinal, multi-center study

Urinary tract infections (UTI) affect approximately 250 million people annually worldwide. Patients often experience a cycle of antimicrobial treatment and recurrent UTI (rUTI) that is thought to be facilitated by a gut reservoir of uropathogenic Escherichia coli (UPEC). 125 patients with UTI caused by an antibiotic-resistant organism (ARO) were enrolled from July 2016 to May 2019 in a longitudinal, multi-center cohort study. Multivariate statistical models were used to assess the relationship between uropathogen colonization and recurrent UTI (rUTI), controlling for clinical characteristics. 644 stool samples and 895 UPEC isolates were interrogated for taxonomic composition, antimicrobial resistance genes, and phenotypic resistance. Cohort UTI gut microbiome profiles were compared against published healthy and UTI reference microbiomes, as well as assessed within-cohort for timepoint- and recurrence-specific differences. Risk of rUTI was not independently associated with clinical characteristics. The UTI gut microbiome was distinct from healthy reference microbiomes in both taxonomic composition and antimicrobial resistance gene (ARG) burden, with 11 differentially abundant taxa at the genus level. rUTI and non-rUTI gut microbiomes in the cohort did not generally differ, but gut microbiomes from urinary tract colonized patients were elevated in E.coli abundance 7-14 days post-antimicrobial treatment. Corresponding UPEC gut isolates from urinary tract colonizing lineages showed elevated phenotypic resistance against 11 of 23 tested drugs compared to non-colonizing lineages. The gut microbiome is implicated in UPEC urinary tract colonization during rUTI, serving as an ARG-enriched reservoir for UPEC. UPEC can asymptomatically colonize the gut and urinary tract, and post-antimicrobial blooms of gut E.coli among urinary tract colonized patients suggest that cross-habitat migration of UPEC is an important mechanism of rUTI. Thus, treatment duration and UPEC populations in both the urinary and gastrointestinal tract should be considered in treating rUTI and developing novel therapeutics. This work was supported in part by awards from the U.S. Centers for Disease Control and Prevention Epicenter Prevention Program (grant U54CK000482; principal investigator, V.J.F.); to J.H.K. from the Longer Life Foundation (an RGA/Washington University partnership), the National Center for Advancing Translational Sciences (grants KL2TR002346 and UL1TR002345), and the National Institute of Allergy and Infectious Diseases (NIAID) (grant K23A1137321) of the National Institutes of Health (NIH); and to G.D. from NIAID (grant R01AI123394) and the Eunice Kennedy Shriver National Institute of Child Health and Human Development (grant R01HD092414) of NIH. R.T.'s research was funded by the Deutsche Forschungsgemeinschaft (DFG; German Research Foundation; grant 402733540). REDCap is Supported by Clinical and Translational Science Award (CTSA) Grant UL1 TR002345 and Siteman Comprehensive Cancer Center and NCI Cancer Center Support Grant P30 CA091842. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.

Molecular Detection of Ureaplasma Urealyticum in Pregnant Woman Suffering from Urinary Tract Infection

Mycoplasma is a genus of bacteria that lack a cell wall, The present study was designed to identify the Ureaplasma urelyticium which causes the pregnant women suffering uti. The study included 200 samples of 150 pregnant women and 50 controls from the Bint Al-Huda teaching Hospital and Al-Haboubi teaching Hospital in the Thi-Qar provainc. The presence of the GPO gene in urine samples by using the PCR used as an indicator for mycoplasma colonization of urinary tract of pregnant, then the species was detected by DNA sequencing. in this study Regarding the GPO gene most of the cases were carry mycoplasmas and majority of the control groups expressing the positive results so that there was no significant statistical differences where (p value = 0.069). The present results recorded that the presence of about 94% homology between studied samples with Ureaplasma urelyticium sequences. Twenty-one, 12 and 6 genetic variations of 16SrRNA gene were identified in Mycoplasma hominis, Mycoplasma, ureaplasma urelyticium. Some variations were variably distributed in the majority of the studied samples. The study showed that the ureaplasma urelyticium.is an important cause of UTI in pregnant women in Iraqi population.

Urinary Tract Infection and Progression to Pyelonephritis: Group B Streptococcus versus E. coli.

Objective Group B Streptococcus (GBS) colonization of the lower urinary tract in pregnancy is associated with severe infections such as chorioamnionitis, endometritis, and pyelonephritis. The objective of this study was to compare rates of progression to pyelonephritis between GBS and Escherichia coli lower urinary tract infections (LUTIs), as well as compare infectious and obstetric morbidity secondary to these pathogens. Study Design Retrospective cohort of pregnant women with LUTIs (asymptomatic bacteria or acute cystitis [AC]) from a single health system between July 2013 and May 2019. Demographic, infectious, antepartum, and intrapartum data were abstracted from medical records of women with GBS or E. coli LUTI. The primary outcome was progression to pyelonephritis. Secondary outcomes included pyelonephritis-related anemia, sepsis, pyelonephritis length of stay (LOS), median gestational age (GA) at delivery, preterm delivery, and low birth weight (LBW). Logistic regression was used to calculate the adjusted odds of the primary outcome. Results Of 729 pregnant women with urinary colonization, 433 were culture positive for one of the aforementioned bacteria, with 189 (43.6%) having GBS and 244 (56.4%) having E. coli. Women with E. coli were more likely to be younger, use tobacco, have a history of AC, and have a history of preterm birth. Rates of progression to pyelonephritis were markedly higher with E. coli (15.6%) than with GBS (1.1%; p < 0.001). Median LOS for pyelonephritis and pyelonephritis-related morbidities did not differ. Median GA at delivery, preterm delivery, and LBW rates also did not differ. In adjusted analysis, controlling for history of AC, insurance status, tobacco use, prior preterm birth, primary infection type, and maternal age, women with GBS LUTI had markedly decreased odds of developing pyelonephritis in pregnancy compared with those with E. coli (adjusted odds ratio: 0.04, 95% confidence interval: 0.01-0.28). Conclusion Escherichia coli infections progress to pyelonephritis in pregnancy at markedly higher rates than GBS, although obstetric outcomes are similar.

Urinary tract infections older adults at Mohammed VI University Hospital of Oujda: case series

This is a 36 months retrospective study from 22 March 2016 to 11 May 2019. The study included urinary specimens of persons aged 65 years or over, hospitalized or consulting at the authors' hospital. Urines were processed according to the recommendations of the medical microbiology reference system and European Committee on Antimicrobial Susceptibility Testing. The authors collected 6552 requests for cytobacteriological examination of urine. Most of the specimens was collected in the middle stream (n=5503; 84%). Cultures were sterile in 49.77% of cases. Positive in 50.22% of cases. Among positive samples we had 53.41% polymorphic cultures, 32.75% urinary tract infection, and 13.82% urinary tract colonization. Gender distribution showed a sex ratio at 0.62. Gram-negative bacilli, with Escherichia coli as the main species, dominated the isolated bacteria. Resistance rates of E. coli strains that we isolated were 70% for amoxicillin, 36.31% for amoxicillin-clavulanate and 25% for ciprofloxacin. A high resistance rate was seen for third generation cephalosporins. Least resistance recorded to nitrofurantoin. ITU in the elderly is diverse and significantly different from that of younger patients, through its high contamination rate, difficulty in acquiring clinical information, high rate of asymptomatic bacteriuria, and high proportion of multidrug resistant bacteria.

E. coli catheter-associated urinary tract infections are associated with distinctive virulence and biofilm gene determinants.

Urinary catheterization facilitates urinary tract colonization by E. coli and increases infection risk. Here, we aimed to identify strain-specific characteristics associated with the transition from colonization to infection in catheterized patients. In a single-site study population, we compared E. coli isolates from patients with catheter-associated asymptomatic bacteriuria (CAASB) to those with catheter-associated urinary tract infection (CAUTI). CAUTI isolates were dominated by a phylotype B2 subclade containing the multidrug-resistant ST131 lineage relative to CAASB isolates, which were phylogenetically more diverse. A distinctive combination of virulence-associated genes was present in the CAUTI-associated B2 subclade. Catheter-associated biofilm formation was widespread among isolates and did not distinguish CAUTI from CAASB strains. Preincubation with CAASB strains could inhibit catheter colonization by multiple ST131 CAUTI isolates. Comparative genomic analysis identified a group of variable genes associated with high catheter biofilm formation present in both CAUTI and CAASB strains. Among these, ferric citrate transport (Fec) system genes were experimentally associated with enhanced catheter biofilm formation using reporter and fecA deletion strains. These results are consistent with a variable role for catheter biofilm formation in promoting CAUTI by ST131-like strains or resisting CAUTI by lower-risk strains that engage in niche exclusion.

Role of metabolism in uropathogenic Escherichia coli.

Uropathogenic Escherichia coli (UPEC) is responsible for more than 75% of urinary tract infections (UTIs) and has been studied extensively to better understand the molecular underpinnings of infection and pathogenesis. Although the macromolecular adaptations UPEC employs - including the expression of virulence factors, adhesion molecules, and iron-acquisition systems - are well described, the role that metabolism plays in enabling infection is still unclear. However, a growing body of literature shows that metabolic function can have a profound impact on which strains can colonize the urinary tract. The goal of this review is to critically appraise this emerging body of literature to better understand the role that nutritional selection plays in enabling urinary tract colonization and the progression of UTIs.

Complete Genome Sequences of Three Lactobacillus gasseri Urine Isolates Obtained from Postmenopausal Women.

ABSTRACTLactobacillus gasseri frequently colonizes the lower urinary tract of healthy women. However, the role of L. gasseri in urinary tract health and the genes required for urinary tract colonization are poorly understood. Herein, we announce the complete genome sequences of three Lactobacillus gasseri isolates collected from the urine of postmenopausal women.

Urease-negative uropathogen Kalamiella piersonii YU22 metabolizes urea by urea carboxylase and allophanate hydrolase enzyme system

Urea is one of the major components of the human urine and its breakdown by the uropathogens occurs mainly through the activity of the enzyme urease. However, a few reports suggest the presence of an alternate enzyme system for urea breakdown namely urea carboxylase (UC) and allophanate hydrolase (AH). We have previously reported the UC and AH system in the genome of a urease-negative uropathogen Kalamiella piersonii YU22 of the novel genus Kalamiella (reclassified recently as Pantoea).To validate the UC and AH activity in the presence of urea, we investigated the growth and urea utilization patterns of this bacterium. Growth kinetics, variations in media pH, NH4-N generation and UC and AH gene expressions were probed using urea-containing media. YU22 was able to grow in M9 media containing urea and increase the pH of the media due to the urea breakdown. Further, significantly higher concentrations of extracellular NH4-N (p < 0.001) was also detected in the cultures along with over-expression of UC and AH genes. The bacterium formed biofilm, and displayed swimming and swarming motilities in presence of urea. Additional glucose supply to urea boosted the colonization but ameliorated the media alkalization and ammonification through suppression of gene expressions encoding UC and AH. These results show that the urease-negative strain YU22 can utilize the UC and AH system for urea metabolism. We propose to further investigate the UC and AH system in other urease-negative uropathogens and its implications for pathogenicity and urinary tract colonization.

InvL, an Invasin-Like Adhesin, Is a Type II Secretion System Substrate Required for Acinetobacter baumannii Uropathogenesis.

ABSTRACTAcinetobacter baumannii is an opportunistic pathogen of growing concern, as isolates are commonly multidrug resistant. While A. baumannii is most frequently associated with pulmonary infections, a significant proportion of clinical isolates come from urinary sources, highlighting its uropathogenic potential. The type II secretion system (T2SS) of commonly used model Acinetobacter strains is important for virulence in various animal models, but the potential role of the T2SS in urinary tract infection (UTI) remains unknown. Here, we used a catheter-associated UTI (CAUTI) model to demonstrate that a modern urinary isolate, UPAB1, requires the T2SS for full virulence. A proteomic screen to identify putative UPAB1 T2SS effectors revealed an uncharacterized lipoprotein with structural similarity to the intimin-invasin family, which serve as type V secretion system (T5SS) adhesins required for the pathogenesis of several bacteria. This protein, designated InvL, lacked the β-barrel domain associated with T5SSs but was confirmed to require the T2SS for both surface localization and secretion. This makes InvL the first identified T2SS effector belonging to the intimin-invasin family. InvL was confirmed to be an adhesin, as the protein bound to extracellular matrix components and mediated adhesion to urinary tract cell lines in vitro. Additionally, the invL mutant was attenuated in the CAUTI model, indicating a role in Acinetobacter uropathogenesis. Finally, bioinformatic analyses revealed that InvL is present in nearly all clinical isolates belonging to international clone 2, a lineage of significant clinical importance. In all, we conclude that the T2SS substrate InvL is an adhesin required for A. baumannii uropathogenesis.

Virulome and genome analyses identify associations between antimicrobial resistance genes and virulence factors in highly drug-resistant Escherichia coli isolated from veal calves.

Food animals are known reservoirs of multidrug-resistant (MDR) Escherichia coli, but information regarding the factors influencing colonization by these organisms is lacking. Here we report the genomic analysis of 66 MDR E. coli isolates from non-redundant veal calf fecal samples. Genes conferring resistance to aminoglycosides, β-lactams, sulfonamides, and tetracyclines were the most frequent antimicrobial resistance genes (ARGs) detected and included those that confer resistance to clinically significant antibiotics (blaCMY-2, blaCTX-M, mph(A), erm(B), aac(6’)Ib-cr, and qnrS1). Co-occurrence analyses indicated that multiple ARGs significantly co-occurred with each other, and with metal and biocide resistance genes (MRGs and BRGs). Genomic analysis also indicated that the MDR E. coli isolated from veal calves were highly diverse. The most frequently detected genotype was phylogroup A-ST Cplx 10. A high percentage of isolates (50%) were identified as sequence types that are the causative agents of extra-intestinal infections (ExPECs), such as ST69, ST410, ST117, ST88, ST617, ST648, ST10, ST58, and ST167, and an appreciable number of these isolates encoded virulence factors involved in the colonization and infection of the human urinary tract. There was a significant difference in the presence of multiple accessory virulence factors (VFs) between MDR and susceptible strains. VFs associated with enterohemorrhagic infections, such as stx, tir, and eae, were more likely to be harbored by antimicrobial-susceptible strains, while factors associated with extraintestinal infections such as the sit system, aerobactin, and pap fimbriae genes were more likely to be encoded in resistant strains. A comparative analysis of SNPs between strains indicated that several closely related strains were recovered from animals on different farms indicating the potential for resistant strains to circulate among farms. These results indicate that veal calves are a reservoir for a diverse group of MDR E. coli that harbor various resistance genes and virulence factors associated with human infections. Evidence of co-occurrence of ARGs with MRGs, BRGs, and iron-scavenging genes (sit and aerobactin) may lead to management strategies for reducing colonization of resistant bacteria in the calf gut.

Transcriptomic and Metabolomic Profiling Reveals That KguR Broadly Impacts the Physiology of Uropathogenic Escherichia coli Under in vivo Relevant Conditions.

Urinary tract infections are primarily caused by uropathogenic Escherichia coli (UPEC). In contrast to the intestinal E. coli strains that reside in nutrient-rich gut environment, UPEC encounter distinct niches, for instance human urine, which is an oxygen- and nutrient-limited environment. Alpha-ketoglutarate (KG) is an abundant metabolite in renal proximal tubule cells; and previously we showed that two-component signaling system (TCS) KguS/KguR contributes to UPEC colonization of murine urinary tract by promoting the utilization of KG as a carbon source under anaerobic conditions. However, knowledge about the KguR regulon and its impact on UPEC fitness is lacking. In this work, we analyzed transcriptomic and metabolomic changes caused by kguR deletion under anaerobiosis when KG is present. Our results indicated that 620 genes were differentially expressed in the ΔkguR mutant, as compared to the wild type; of these genes, 513 genes were downregulated and 107 genes were upregulated. Genes with substantial changes in expression involve KG utilization, acid resistance, iron uptake, amino acid metabolism, capsule biosynthesis, sulfur metabolism, among others. In line with the transcriptomics data, several amino acids (glutamate, lysine, etc.) and uridine 5′-diphosphogalactose (involved in capsule biosynthesis) were significantly less abundant in the ΔkguR mutant. We then confirmed that the ΔkguR mutant, indeed, was more sensitive to acid stress than the wild type, presumably due to downregulation of genes belonging to the glutamate-dependent acid resistance system. Furthermore, using gene expression and electrophoretic mobility shift assays (EMSAs), we demonstrate that KguR autoregulates its own expression by binding to the kguSR promoter region. Lastly, we performed a genome-wide search of KguR binding sites, and this search yielded an output of at least 22 potential binding sites. Taken together, our data establish that in the presence of KG, KguR broadly impacts the physiology of UPEC under anaerobiosis. These findings greatly further our understanding of KguS/KguR system as well as UPEC pathobiology.

1083. Phase 1b Results of Pharmacokinetics, Pharmacodynamics, and Safety for LBP-EC01, a CRISPR-Cas3 Enhanced Bacteriophage Cocktail Targeting Escherichia coli that Cause Urinary Tract Infections

BackgroundLBP-EC01 is the first CRISPR-engineered bacteriophage product to successfully complete Phase 1b testing in a clinical program designed to address infections caused by E. coli initially targeting urinary tract infections (UTIs). Thirty-six subjects were enrolled in this randomized, double blind study to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of LBP-EC01 in patients with lower urinary tract colonization caused by E. coli.MethodsResultsNo drug-related Treatment Emergent Adverse Events (TEAEs) were observed. All nondrug related TEAEs were Grade 2 or below and there were no tolerability signals associated with LBP-EC01.A modified ITT (mITT) population was defined to assess PK in subjects treated with LBP-EC01 (n=17). Subjects were removed from the PK analysis who had missing or insufficient colonization at baseline (n=3), were exposed to antibiotics during screening or study conduct (n=3) or exhibited a non-drug related SAE (n=1). Of these subjects, 12 were found to be sensitive to LBP-EC01 and of these, 10 (83%) showed phage amplification. A PD analysis compared the mITT populations of LBP-EC01 vs. placebo (n=6) and showed that the LBP-EC01 arm had a decrease in E. coli that was greatest within 24 hours of initial treatment and remained below baseline across the entire treatment period. The placebo arm showed increased levels of E. coli and higher variability over the treatment period. An average difference of 2-3 log (100x to 1,000x) existed in urine E. coli concentration (CFU/mL) between the LBP-EC01 and placebo arms across the duration of the treatment period.ConclusionLBP-EC01 has proved to be safe and well-tolerated in this Phase 1b study of subjects colonized by E. coli. In addition, phage amplification was observed in patients with E. coli isolates sensitive to LBP-EC01, demonstrating a clear proof of mechanism. Finally, the apparent difference in PD effect between LBP-EC01 and placebo which was irrespective of MDR status, provides promise that LBP-EC01 may someday be an excellent option for patients suffering from UTIs caused by E. coli, especially in strains that are resistant to conventional antibiotics.Disclosures Dave ousterout, PhD, InceptorBio (Advisor or Review Panel member, Shareholder)Locus Biosciences (Employee, Shareholder)

Elimination of Routine Urinalysis before Elective Orthopaedic Surgery Reduces Antibiotic Utilization without Impacting Catheter-associated Urinary Tract Infection or Surgical Site Infection Rates.

PurposeRoutine preoperative urinalysis has been the standard of care for the orthopedic population for decades, regardless of symptoms. Studies have demonstrated antibiotic overuse and low concordance between bacteria cultured from the surgical wound and the urine. Testing and treatment of asymptomatic urinary tract colonization before total joint arthroplasty (TJA) is unnecessary and increases patient risk. We investigated reducing antibiotic use by (1) modifying testing algorithms to target patients at risk, (2) modifying reflex to culture criteria, and (3) providing treatment guidelines.Materials and MethodsA pre-post study was conducted to determine identify the impact of eliminating universal urinalysis prior to TJA on surgical site infection (SSI) and catheter-associated urinary tract infection (CAUTI) rates and number of antibiotic prescriptions. Patients who underwent primary hip or knee TJA or spinal fusions from February 2016 to March 2018 were included. Patient data was collected for pre- and post-practice change period (February 2016-October 2016 and August 2017-March 2018). Patient demographics, urinalysis results, cultures, and prescriptions were analyzed retrospectively from every tenth chart in the pre-period and prospectively on all patients in the post-period.ResultsA total of 4,663 patients were studied. There was a 96% decrease in urinalyses performed (P<0.0001), and a 93% reduction rate in antibiotic utilization (P<0.001). No significant difference in SSI and CAUTI rates was observed (P>0.05).ConclusionThe elimination of routine urinalysis before orthopedic surgery resulted in a reduction in antibiotic utilization with no significant change in the SSI or CAUTI rates. Cost savings resulted from reduced antibiotic usage.

Bis-molybdopterin guanine dinucleotide modulates hemolysin expression under anaerobiosis and contributes to fitness in vivo in uropathogenic Escherichia coli.

Uropathogenic Escherichia coli (UPEC) is the primary causative agent of urinary tract infections (UTIs). Successful urinary tract colonization requires appropriate expression of virulence factors in response to host environmental cues, such as limited oxygen and iron availability. Hemolysin is a pore-forming toxin, and its expression correlates with the severity of UPEC infection. Previously, we showed that hemolysin expression is enhanced under anaerobic conditions; however, the genetic basis and regulatory mechanisms involved remain undefined. Here, a transposon-based forward screen identified bis-molybdopterin guanine dinucleotide cofactor (bis-MGD) biosynthesis as an important factor for a full transcription of hemolysin under anaerobiosis but not under aerobiosis. bis-MGD positively influences hemolysin transcription via c3566-c3568, an operon immediately upstream of and cotranscribed with hlyCABD. Furthermore, suppressor mutation analysis identified the nitrogen regulator NtrC as a direct repressor of c3566-c3568-hlyCABD expression, and intact bis-MGD biosynthesis downregulated ntrC expression, thus at least partially explaining the positive role of bis-MGD in modulating hemolysin expression. Finally, bis-MGD is involved in hemolysin-mediated uroepithelial cell death and contributes to the competitive fitness of UPEC in a murine model of UTI. Collectively, our data establish that bis-MGD biosynthesis plays a crucial role in UPEC fitness in vivo, thus providing a potential target for combatting UTIs.

Genetic Background and Antibiotic Resistance Profiles of K. pneumoniae NDM-1 Strains Isolated from UTI, ABU, and the GI Tract, from One Hospital in Poland, in Relation to Strains Nationally and Worldwide.

In recent years, there has been an observed increase in infections caused by carbapenem-resistant Klebsiella pneumonia (Kp) strains. The aim of this study was the phenotypic and genotypic analysis of eight K. pneumoniae NDM (Kp NDM) isolates, recovered in Poland during the years 2016 and 2018 from seven patients with urinary tract infections (UTIs), asymptomatic bacteriuria (ABU), or colonization of the gut. PCR melting profile genotyping indicated a close relationship between the strains derived from 2018, which were not related to the strain isolated in 2016. WGS results were analyzed in relation to international Kp isolates. Clonal and phylogenetic analyses were performed based on multilocus sequence typing (MLST) and single nucleotide polymorphisms (SNPs) of the core genome. The metallo-β-lactamase was assigned to the NDM-1 type and the sequence was identified as ST11. Eleven antimicrobial resistance genes were detected, mostly from plasmid contigs. Unprecedented profiles of plasmid replicons were described with the IncFII/pKPX-1 dominant replicon. In terms of the KL24 and O2v1 capsular antigen profiles, these isolates corresponded to Greek strains. Strains isolated from UTI, ABU, and colonization GI tract patients were not carrying environment-specific virulence genes. Based on the assessment of strain relationships at the genome level and their direction of evolution, the international character of the sublines was demonstrated, with a documented epidemic potential in Poland and Greece. In conclusion, some groups of patients, e.g., renal transplant recipients or those with complicated UTIs, who are frequently hospitalized and undergoing antibiotic therapy, should be monitored not only for the risk of UTI, but also for colonization by Kp NDM strains.

The RyfA small RNA regulates oxidative and osmotic stress responses and virulence in uropathogenic Escherichia coli.

Urinary tract infections (UTIs) are a common bacterial infectious disease in humans, and strains of uropathogenic Escherichia coli (UPEC) are the most frequent cause of UTIs. During infection, UPEC must cope with a variety of stressful conditions in the urinary tract. Here, we demonstrate that the small RNA (sRNA) RyfA of UPEC strains is required for resistance to oxidative and osmotic stresses. Transcriptomic analysis of the ryfA mutant showed changes in expression of genes associated with general stress responses, metabolism, biofilm formation and genes coding for cell surface proteins. Inactivation of ryfA in UPEC strain CFT073 decreased urinary tract colonization in mice and the ryfA mutant also had reduced production of type 1 and P fimbriae (pili), adhesins which are known to be important for UTI. Furthermore, loss of ryfA also reduced UPEC survival in human macrophages. Thus, ryfA plays a key regulatory role in UPEC adaptation to stress, which contributes to UTI and survival in macrophages.

Epidemiology and risk factors for ureteral stent-associated urinary tract infections in non-transplanted renal patients: a systematic review of the literature

Pathophysiology and risk factors for Ureteral Stent-Associated Urinary Tract Infection (USAUTI) have been poorly investigated. This situation results in highly diverse practices regarding USAUTI prevention, diagnosis and treatment. The aim of the present study was to describe the epidemiology and risk factors for USAUTI in non-transplanted patients. We conducted a systematic literature review based on a comprehensive PubMed® bibliographic strategy, between October 1998 and March 2020. The methodological quality of the studies included was analyzed according to dedicated grids. The main endpoints were the correlation between different potential risk factors and infection ureteral stent-associated urinary tract infection or colonization rate. Conclusions and their level of evidence were reported on the basis of a critical analysis of the best available scientific evidence. This work has been submitted to a national review, which enabled the potentially divergent opinions of experts to be collected, thereby ensuring adequate quality of data. Twenty-six studies out of the 505 articles identified, were included in the final analysis. Staphylococcus spp, E. coli, Klebsiella spp, Pseudomona aeruginosa, Enterococcus spp. and Candida spp. were the microorganisms most often responsible for asymptomatic bacteriuria (ABU) or USAUTI. Longer indwelling time, diabetes mellitus, female gender, chronic renal failure, diabetic nephropathy and cancer were identified as risk factors for ABU and ureteral stent colonization. No specific risk factor for UTI was identified in the literature studied. A causal relationship between ureteral stent colonization and USAUTI or urosepsis remains to be demonstrated.

Peptidoglycan Endopeptidase Spr of Uropathogenic Escherichia coli Contributes to Kidney Infections and Competitive Fitness During Bladder Colonization.

Uropathogenic E scherichia coli (UPEC) is the most common pathogen of urinary tract infections (UTIs). Antibiotic therapy is the conventional measure to manage such infections. However, the rapid emergence of antibiotic resistance has reduced the efficacy of antibiotic treatment. Given that the bacterial factors required for the full virulence of the pathogens are potential therapeutic targets, identifying such factors may facilitate the development of novel therapeutic strategies against UPEC UTIs. The peptidoglycan (PG) endopeptidase Spr (also named MepS) is required for PG biogenesis in E. coli. In the present study, we found that Spr deficiency attenuated the ability of UPEC to infect kidneys and induced a fitness defect during bladder colonization in a mouse model of UTI. Based on the liquid chromatography (LC)/mass spectrometry (MS)/MS analysis of the bacterial envelope, spr deletion changed the levels of some envelope-associated proteins, suggesting that Spr deficiency interfere with the components of the bacterial structure. Among the proteins, FliC was significantly downregulated in the spr mutant, which is resulted in reduced motility. Lack of Spr might hinder the function of the flagellar transcriptional factor FlhDC to decrease FliC expression. The motility downregulation contributed to the reduced fitness in urinary tract colonization. Additionally, spr deletion compromised the ability of UPEC to evade complement-mediated attack and to resist intracellular killing of phagocytes, consequently decreasing UPEC bloodstream survival. Spr deficiency also interfered with the UPEC morphological switch from bacillary to filamentous shapes during UTI. It is known that bacterial filamentation protects UPEC from phagocytosis by phagocytes. In conclusion, Spr deficiency was shown to compromise multiple virulence properties of UPEC, leading to attenuation of the pathogen in urinary tract colonization and bloodstream survival. These findings indicate that Spr is a potential antimicrobial target for further studies attempting to develop novel strategies in managing UPEC UTIs.

First Report of Pathogenic Bacterium Kalamiella piersonii Isolated from Urine of a Kidney Stone Patient: Draft Genome and Evidence for Role in Struvite Crystallization.

Uropathogenic bacteria are widely distributed in the environment and urinary tract infection is implicated in kidney stone disease. Here, we report on a urease negative bacterium Kalamiella piersonii (strain YU22) isolated from the urine of a struvite stone (MgNH4PO4·6H2O) patient. The closest species, K. piersonii IIIF1SW-P2T was reported from International Space Station samples. However, there are no earlier reports on its human association. Using whole genome and experimental analysis, its involvement in urinary tract colonization and struvite crystallization was explored. The strain YU22 showed many virulence factors that are needed for host cell invasion and colonization including cell adhesion factors, swimming and swarming motilities, biofilm and siderophore among others. In vitro infection studies in HEK-293T cells demonstrated the host cell attachment and killing. It was able to utilize amino acids as sole carbon source and showed growth in synthetic and healthy urine establishing metabolic adaptation to urinary tract. Increased pH and availability of ammonium ions from amino acid breakdown promoted struvite crystallization. The results from this study support the involvement of urease negative uropathogen in the struvite lithogenesis. Further studies on other isolates of K. peirsonii are warranted to assess its health risks.