Outcomes of asymptomatic histologic pyelonephritis of kidney transplant.

BACKGROUND: Urinary Tract Infections are the most common post-transplant infection and can have varied presentations. This study aimed to describe the outcomes of kidney transplant recipients with asymptomatic histologic pyelonephritis on allograft biopsy. Histologic Pyelonephritis was defined as neutrophil cast or neutrophilic tubulitis, interstitial infiltrates with predominant neutrophils, and no evidence of rejection or glomerulonephritis on biopsy. METHODS: The study included 123 kidney transplant recipients, of whom 95 underwent protocol biopsies, and 28 had biopsies for elevated creatinine within the first 2 years of a kidney transplant. RESULTS: The mean age of the cohort was 55.3 years, with 52% females and 78% deceased donor transplants. The risk factors for asymptomatic histologic pyelonephritis were recipient female sex (OR 1.89, 1.3-2.7, diabetes mellitus (OR 2.479, 1.687-3.645), and deceased donation (OR 1.69, 1.098-2.63). The incidence of asymptomatic pyelonephritis on protocol biopsy was 1.7%, with 52% having positive urine cultures and Escherichia coli being the most common bacteria. Subjects with asymptomatic pyelonephritis had inferior graft survival compared to the matched cohort HR 1.88 (1.06-3.35), p = .0281. In addition, of these 123 subjects, 68 (55%) subsequently developed pyelonephritis, and 34 subjects had pyelonephritis within 6 months after this episode. Subjects with recurrent infections exhibited lower survival HR 2.86 (1.36-6.02) and a trend toward higher rejection risk. CONCLUSION: Asymptomatic histologic pyelonephritis can occur in kidney transplant recipients and is associated with inferior graft survival.

Szechwan Lovage Rhizome Extract Improves Renal Function and Alleviates Inflammatory Responses in Pyelonephritis Rats Infected with Escherichia Coli via IL-6/STAT3 Axis.

The objective of this study was to probe the effect and mechanism of Szechwan Lovage Rhizome (Chuanxiong, CX) extract on renal function (RF) and inflammatory responses (IRs) in acute pyelonephritis (APN) rats infected with Escherichia coli (E. coli). Fifteen SD rats were randomized to intervention, model and control groups. Rats in the control were fed normally without treatment, rats in the APN model were infected with E. coli, and rats in the intervention group were intragastrically administered CX extract after infection with E. coli. HE staining detected pathological changes in the kidney tissues in rats. Levels of renal function indexes and inflammatory factors (IFs) were measured by ELISA and an automatic biochemical analyzer. Besides, levels of IL-6/signal transducer and activator of transcription 3 (STAT3) pathway-related genes in rat kidney tissue were detected by qRT-PCR and western blot. the experimental results showed that IL-1ß, IL-8, TNF-α and RF levels were the highest in the model group and the lowest in the control group, with those of the intervention group in between (P<0.05). Besides, the IL-6/STAT3 axis was markedly activated in the model group but inhibited in the intervention group (P<0.05). Subsequently, activated IL-6/STAT3 signal promoted IFs (IL-1ß, IL-8 and TNF-α) and RF (BUN, Scr, ß2-MG and UA), but this effect was offset after CX treatment (P<0.05). In conclusion, CX extract could improve RF and inhibit IRs of APN rats infected with E. coli by inhibiting the IL-6/STAT3 axis, which may be a new choice for APN treatment in the future.

Protective role for C3aR in experimental chronic pyelonephritis.

Emerging evidence suggest that C3aR plays important roles in homeostasis, host defense and disease. Although it is known that C3aR is protective in several models of acute bacterial infections, the role for C3aR in chronic infection is largely unknown. Here we show that C3aR is protective in experimental chronic pyelonephritis. Global C3aR deficient (C3ar-/- ) mice had higher renal bacterial load, more pronounced renal histological lesions, increased renal apoptotic cell accumulation, tissue inflammation and extracellular matrix deposition following renal infection with uropathogenic E. coli (UPEC) strain IH11128, compared to WT control mice. Myeloid C3aR deficient (Lyz2-C3ar-/- ) mice exhibited a similar disease phenotype to global C3ar-/- mice. Pharmacological treatment with a C3aR agonist reduced disease severity in experimental chronic pyelonephritis. Furthermore, macrophages of C3ar-/- mice exhibited impaired ability to phagocytose UPEC. Our data clearly demonstrate a protective role for C3aR against experimental chronic pyelonephritis, macrophage C3aR plays a major role in the protection, and C3aR is necessary for phagocytosis of UPEC by macrophages. Our observation that C3aR agonist curtailed the pathology suggests a therapeutic potential for activation of C3aR in chronic infection.

[Modern algorithm of diagnosis and treatment of acute gestational pyelonephritis in a large industrial city].

THE PURPOSE OF THE STUDY: to develop a modern algorithm for the diagnosis and treatment of acute gestational pyelonephritis in a large industrial city and to study the possibilities of phytotherapy as an integral part of this algorithm. MATERIALS AND METHODS: The study consisted of two stages and included 629 patients treated over 12 years (2010-2021) in Perm city with a population of 1.1 million people. At the first stage, the developed algorithm for the diagnosis and treatment of acute gestational pyelonephritis in 440 pregnant women was tested. A city emergency center for patients with gestational pyelonephritis was created with 3 urologists and related specialists on duty around the clock, what accelerated hospitalization timelines by 2.1 times. The patients underwent a level 1 examination, which included ultrasound examination, urine bacteriology and other methods. Patients in serve condition underwent, a level 2 examination, which included magnetic resonance imaging (MRI), ultrasound Dopplerography (USDG) and extended laboratory tests. RESULTS: During an urgent examination, acute purulent pyelonephritis was diagnosed in 27 (6.1%) patients who underwent 13 open surgeries (11 organ-preserving, 2 nephroectomies) and 14 minimally invasive (percutaneous nephrostomy, puncture of a kidney abscess) within 2-5 hours from the moment of hospitalization. Serve obstructive pyelonephritis was diagnosed in 286 patients, the passage of urine was restored by the installation of a stent or catheterization of the ureter. Conservative antibacterial therapy was performed in 127 patients with serous non-obstructive pyelonephritis. Positive results of treatment were observed in 439 (99.8%) patients: recovery in 95%, significant improvement in 4.8%, with a mortality rate of 0.2%. Bed-day decreased by 30.4%. At the second stage, a comparative randomized study was conducted during 4 years with 189 pregnant women with acute serous pyelonephritis enrolled. In the group 1 (n=94) patients received standard therapy according to the implemented algorithm, in the group 2 (n=95) patients had 60-day use of Canephron N. In the group 2, treatment results were better: recovery was achieved in 96.8% of patients, improvement in 3.2%, the number of pregnant women with leukocyturia and bacteriuria decreased 4.1 times, which prevented the occurrence of repeated attacks of acute pyelonephritis. Compared with standard therapy, Canephron N increased glomerular filtration by 12,3%, diuresis by 14.2%, increased urea excretion function of the kidneys, sanitized the urinary tract at an earlier timelines, reduced the number of premature births and the birth of dead and premature babies. CONCLUSION: As a result of the development and implementation of an algorithm for the diagnosis and treatment of acute gestational pyelonephritis and creation of the treatment center for such patients, it was possible to reduce significantly the time of hospitalization and inpatient treatment and achieve good treatment results in 99.8% of patients. The inclusion of long-term phytotherapy with Canephron N in the treatment regimen increased the effectiveness of treatment, improved kidney function in patients, significantly reduced the number of pregnant women with leukocyturia and bacteriuria, and reduced the risk of a repeated attack of pyelonephritis.

Renal Denervation Exacerbates LPS- and Antibody-induced Acute Kidney Injury, but Protects from Pyelonephritis in Mice.

BACKGROUND: Renal denervation (RDN) is an invasive intervention to treat drug-resistant arterial hypertension. Its therapeutic value is contentious. Here we examined the effects of RDN on inflammatory and infectious kidney disease models in mice. METHODS: Mice were unilaterally or bilaterally denervated, or sham operated, then three disease models were induced: nephrotoxic nephritis (NTN, a model for crescentic GN), pyelonephritis, and acute endotoxemic kidney injury (as a model for septic kidney injury). Analytical methods included measurement of renal glomerular filtration, proteinuria, flow cytometry of renal immune cells, immunofluorescence microscopy, and three-dimensional imaging of optically cleared kidney tissue by light-sheet fluorescence microscopy followed by algorithmic analysis. RESULTS: Unilateral RDN increased glomerular filtration in denervated kidneys, but decreased it in the contralateral kidneys. In the NTN model, more nephritogenic antibodies were deposited in glomeruli of denervated kidneys, resulting in stronger inflammation and injury in denervated compared with contralateral nondenervated kidneys. Also, intravenously injected LPS increased neutrophil influx and inflammation in the denervated kidneys, both after unilateral and bilateral RDN. When we induced pyelonephritis in bilaterally denervated mice, both kidneys contained less bacteria and neutrophils. In unilaterally denervated mice, pyelonephritis was attenuated and intrarenal neutrophil numbers were lower in the denervated kidneys. The nondenervated contralateral kidneys harbored more bacteria, even compared with sham-operated mice, and showed the strongest influx of neutrophils. CONCLUSIONS: Our data suggest that the increased perfusion and filtration in denervated kidneys can profoundly influence concomitant inflammatory diseases. Renal deposition of circulating nephritic material is higher, and hence antibody- and endotoxin-induced kidney injury was aggravated in mice. Pyelonephritis was attenuated in denervated murine kidneys, because the higher glomerular filtration facilitated better flushing of bacteria with the urine, at the expense of contralateral, nondenervated kidneys after unilateral denervation.

TcpC inhibits neutrophil extracellular trap formation by enhancing ubiquitination mediated degradation of peptidylarginine deiminase 4.

TcpC is a multifunctional virulence factor of uropathogenic E. coli (UPEC). Neutrophil extracellular trap formation (NETosis) is a crucial anti-infection mechanism of neutrophils. Here we show the influence of TcpC on NETosis and related mechanisms. We show NETosis in the context of a pyelonephritis mouse model induced by TcpC-secreting wild-type E. coli CFT073 (CFT073wt) and LPS-induced in vitro NETosis with CFT073wt or recombinant TcpC (rTcpC)-treated neutrophils are inhibited. rTcpC enters neutrophils through caveolin-mediated endocytosis and inhibits LPS-induced production of ROS, proinflammatory cytokines and protein but not mRNA levels of peptidylarginine deiminase 4 (PAD4). rTcpC treatment enhances PAD4 ubiquitination and accumulation in proteasomes. Moreover, in vitro ubiquitination kit analyses show that TcpC is a PAD4-targetd E3 ubiquitin-ligase. These data suggest that TcpC inhibits NETosis primarily by serving as an E3 ligase that promotes degradation of PAD4. Our findings provide a novel mechanism underlying TcpC-mediated innate immune evasion.

The bacteria and the host: a story of purinergic signaling in urinary tract infections.

The local environment forces a selection of bacteria that might invade the urinary tract, allowing only the most virulent to access the kidney. Quite similar to the diet in setting the stage for the gut microbiome, renal function determines the conditions for bacteria-host interaction in the urinary tract. In the kidney, the term local environment or microenvironment is completely justified because the environment literally changes within a few micrometers. The precise composition of the urine is a function of the epithelium lining the microdomain, and the microenvironment in the kidney shows more variation in the content of nutrients, ion composition, osmolality, and pH than any other site of bacteria-host interaction. This review will cover some of the aspects of bacterial-host interaction in this unique setting and how uropathogenic bacteria can alter the condition for bacteria-host interaction. There will be a particular focus on the recent findings regarding how bacteria specifically trigger host paracrine signaling, via release of extracellular ATP and activation of P2 purinergic receptors. These finding will be discussed from the perspective of severe urinary tract infections, including pyelonephritis and urosepsis.

Severe infection including disseminated herpes zoster triggered by subclinical Cushing's disease: a case report.

BACKGROUND: Subclinical Cushing's disease (SCD) is defined by corticotroph adenoma-induced mild hypercortisolism without typical physical features of Cushing's disease. Infection is an important complication associated with mortality in Cushing's disease, while no reports on infection in SCD are available. To make clinicians aware of the risk of infection in SCD, we report a case of SCD with disseminated herpes zoster (DHZ) with the mortal outcome. CASE PRESENTATION: An 83-year-old Japanese woman was diagnosed with SCD, treated with cabergoline in the outpatient. She was hospitalized for acute pyelonephritis, and her fever gradually resolved with antibiotics. However, herpes zoster appeared on her chest, and the eruptions rapidly spread over the body. She suddenly went into cardiopulmonary arrest and died. Autopsy demonstrated adrenocorticotropic hormone-positive pituitary adenoma, renal abscess, and DHZ. CONCLUSIONS: As immunosuppression caused by SCD may be one of the triggers of severe infection, the patients with SCD should be assessed not only for the metabolic but also for the immunodeficient status.

Preadmission kidney function and risk of acute kidney injury in patients hospitalized with acute pyelonephritis: A Danish population-based cohort study.

BACKGROUND AND OBJECTIVES: Only few smaller studies have examined if impaired kidney function increases the risk of acute kidney injury in patients with acute pyelonephritis. Therefore, we estimated 30-day risk of acute kidney injury by preadmission kidney function in patients with acute pyelonephritis. Furthermore, we examined if impaired kidney function was a risk factor for development of acute kidney injury in pyelonephritis patients. METHODS: This cohort study included patients with a first-time hospitalization with pyelonephritis from 2000 to 2017. Preadmission kidney function (estimated glomerular filtration rate (eGFR) <30, 30-44, 45-59, 60-89, and ≥90 ml/min/1.73 m2) and acute kidney injury within 30 days after admission were assessed using laboratory data on serum creatinine. The absolute 30-days risk of acute kidney injury was assessed treating death as a competing risk. The impact of eGFR on the odds of acute kidney injury was compared by odds ratios (ORs) with 95% confidence intervals estimated using logistic regression adjusted for potential confounding factors. RESULTS: Among 8,760 patients with available data on preadmission kidney function, 25.8% had a preadmission eGFR <60. The 30-day risk of acute kidney injury was 16% among patients with preadmission eGFR ≥90 and increased to 22%, 33%, 42%, and 47% for patients with preadmission eGFR of 60-89, 45-59, 30-44, and <30 respectively. Compared with eGFR≥90, the adjusted ORs for the subgroups with eGFR 60-89, 45-59, 30-45, and <30 were 0.95, 1.32, 1.78, and 2.19 respectively. CONCLUSION: Acute kidney injury is a common complication in patients hospitalized with acute pyelonephritis. Preadmission impaired kidney function is a strong risk factor for development of acute kidney injury in pyelonephritis patients and more attention should be raised in prevention of pyelonephritis in patients with a low kidney function.

Adjuvant corticosteroids for prevention of kidney scarring in children with acute pyelonephritis: a systematic review and meta-analysis.

BACKGROUND: Acute pyelonephritis in children may result in permanent kidney scarring that is primarily caused by inflammation during acute infection. Antibiotic therapy alone is not enough to significantly reduce kidney scarring, and adjuvant corticosteroid therapy has shown a significant reduction in inflammatory cytokines in urine prompting its evaluation in randomised controlled trials. A few clinical trials showed a trend towards a reduction in renal scarring but did not have an adequate sample size to show a significant effect. Therefore, we planned to synthesise the available evidence on the role of corticosteroids as adjuvant therapy in reducing kidney scarring. OBJECTIVE: To assess the efficacy and safety of adjuvant corticosteroid therapy for the prevention of kidney scarring in children with acute pyelonephritis. DESIGN: Systematic review and meta-analysis. SETTING: Community-acquired febrile urinary tract infections. PATIENTS: Children (less than 18 years) with acute pyelonephritis. INTERVENTION: Adjuvant corticosteroid therapy (along with antibiotic treatment). MAIN OUTCOME MEASURES: Primary: efficacy in preventing kidney scarring; secondary: serious adverse events associated with corticosteroid therapy. RESULTS: Three randomised trials (529 children) were included. Corticosteroids are effective in lowering the risk of kidney scarring as compared with placebo (risk ratio (RR): 0.57; 95% CI 0.36 to 0.90). No significant increase risk of bacteraemia (RR: 1.38; 95% CI 0.23 to 8.23) and hospitalisation (RR: 0.87; 95% CI 0.3 to 2.55) was observed in corticosteroid group. CONCLUSION: Moderate quality evidence suggests that short duration 'adjuvant corticosteroid therapy' along with routine antibiotic therapy in acute febrile urinary tract infection significantly reduces the risk of kidney scarring without any significant adverse effects.

Clinical manifestations, laboratory markers, and renal ultrasonographic examinations in 1-month to 12-year-old Iranian children with pyelonephritis: a six-year cross-sectional retrospective study.

BACKGROUND: Upper urinary tract infection (UTI) or pyelonephritis may increase the pathogenesis rate and risk of severe complications in children due to kidney atrophy. OBJECTIVE: A set of clinical symptoms, laboratory markers, and ultrasound findings were assessed to achieve the early diagnosis and prognosis of pyelonephritis in hospitalized pediatrics. METHODS: A cross-sectional study with 104 Iranian children (95 girls and 9 boys) aged 1 month to 12 years with acute pyelonephritis during 2012-2018 was conducted. The ultrasound examination of kidneys and urinary tract during hospitalization, the incidence of clinical symptoms, and laboratory markers in blood and urine were monitored to identify the best predictive factors of early diagnosis of this bacterial infection. RESULTS: Three-fourth of the patients had one of the four clinical symptoms of abdominal pain, constipation, dysuria, and vomiting, while others were asymptomatic. A much frequency of pyuria (88.46%), Escherichia coli in urine (92.31%), leukocytosis (81.73%), and high ESR (> 10 mm/h, 92.30%) and CRP (> 10 mg/L, 82.82%) was observed. The kidney and urinary tract ultrasonography only in 32.7% of children revealed findings in favor of pyelonephritis (cystitis, ureteral stones, and hydronephrosis). CONCLUSION: There was a high frequency of clinical signs and laboratory markers associated with pyelonephritis. Ultrasound alone was not an efficient tool to track febrile UTI as most patients presented normal sonography.

Consistent alteration of chain length-specific ceramides in human and mouse fibrotic kidneys.

BACKGROUND: Several studies revealed alterations of single sphingolipid species, such as chain length-specific ceramides, in plasma and serum of patients with kidney diseases. Here, we investigated whether such alterations occur in kidney tissue from patients and mice suffering from renal fibrosis, the common endpoint of chronic kidney diseases. METHODS: Human fibrotic kidney samples were collected from nephrectomy specimens with hydronephrosis and/or pyelonephritis. Healthy parts from tumor nephrectomies served as nonfibrotic controls. Mouse fibrotic kidney samples were collected from male C57BL/6J mice treated with an adenine-rich diet for 14 days or were subjected to 7 days of unilateral ureteral obstruction (UUO). Kidneys of untreated mice and contralateral kidneys (UUO) served as respective controls. Sphingolipid levels were detected by LC-MS/MS. Fibrotic markers were analyzed by TaqMan® analysis and immunohistology. RESULTS: Very long-chain ceramides Cer d18:1/24:0 and Cer d18:1/24:1 were significantly downregulated in both fibrotic human kidney cortex and fibrotic murine kidney compared to respective control samples. These effects correlate with upregulation of COL1α1, COL3α1 and αSMA expression in fibrotic human kidney cortex and fibrotic mouse kidney. CONCLUSION: We have shown that very long-chain ceramides Cer d18:1/24:0 and Cer d18:1/24:1 are consistently downregulated in fibrotic kidney samples from human and mouse. Our findings support the use of in vivo murine models as appropriate translational means to understand the involvement of ceramides in human kidney diseases. In addition, our study raises interesting questions about the possible manipulation of ceramide metabolism to prevent progression of fibrosis and the use of ceramides as potential biomarkers of chronic kidney disease.

Metabolic acidosis exacerbates pyelonephritis in mice prone to vesicoureteral reflux.

Acute pyelonephritis is a common, serious bacterial infection in children. The prevalence of acute pyelonephritis is due at least in part to vesicoureteral reflux (VUR). Although an association between abnormalities in electrolyte and acid-base balance and pyelonephritis is common in young children, the impact of metabolic acidosis (MA) on progression of acute pyelonephritis is not fully understood. In this study, the effect of MA on pyelonephritis was studied in C3H mouse strains prone to VUR. MA induced by ammonium chloride supplementation in food specifically impaired clearance of urinary tract infection with uropathogenic Escherichia. coli (UPEC-UTI) in innate immune competent C3H strains (HeOuJ, HeN), whereas kidney UPEC burden in Tlr-4-deficient HeJ mice was unaffected. Antibody-mediated depletion of myeloid cells (monocytes, neutrophil) markedly increased UPEC burden in the bladder and kidney confirming the pivotal role of neutrophils and tissue-resident macrophages in clearance of UPEC-UTI. MA concurrent with UPEC-UTI markedly increased expression of cytokine (TNFα, IL-1ß, IL-6) and chemokine (CXCL 1, 2, and 5) mRNA in isolated kidney CD cells and kidney neutrophil infiltrates were increased four- to fivefold compared to normal, UPEC-infected mice. Thus, MA intensified pyelonephritis and increased the risk of kidney injury by impairing clearance of UPEC-UTI and potentiating renal inflammation characterized by an elevated kidney neutrophil infiltrate.

Androgen-Influenced Polarization of Activin A-Producing Macrophages Accompanies Post-pyelonephritic Renal Scarring.

Ascending bacterial pyelonephritis, a form of urinary tract infection (UTI) that can result in hospitalization, sepsis, and other complications, occurs in ~250,000 US patients annually; uropathogenic Escherichia coli (UPEC) cause a large majority of these infections. Although UTIs are primarily a disease of women, acute pyelonephritis in males is associated with increased mortality and morbidity, including renal scarring, and end-stage renal disease. Preclinical models of UTI have only recently allowed investigation of sex and sex-hormone effects on pathogenesis. We previously demonstrated that renal scarring after experimental UPEC pyelonephritis is augmented by androgen exposure; testosterone exposure increases both the severity of pyelonephritis and the degree of renal scarring in both male and female mice. Activin A is an important driver of scarring in non-infectious renal injury, as well as a mediator of macrophage polarization. In this work, we investigated how androgen exposure influences immune cell recruitment to the UPEC-infected kidney and how cell-specific activin A production affects post-pyelonephritic scar formation. Compared with vehicle-treated females, androgenized mice exhibited reduced bacterial clearance from the kidney, despite robust myeloid cell recruitment that continued to increase as infection progressed. Infected kidneys from androgenized mice harbored more alternatively activated (M2) macrophages than vehicle-treated mice, reflecting an earlier shift from a pro-inflammatory (M1) phenotype. Androgen exposure also led to a sharp increase in activin A-producing myeloid cells in the infected kidney, as well as decreased levels of follistatin (which normally antagonizes activin action). As a result, infection in androgenized mice featured prolonged polarization of macrophages toward a pro-fibrotic M2a phenotype, accompanied by an increase in M2a-associated cytokines. These data indicate that androgen enhancement of UTI severity and resulting scar formation is related to augmented local activin A production and corresponding promotion of M2a macrophage polarization.

TGFß1 orchestrates renal fibrosis following Escherichia coli pyelonephritis.

Renal scarring after pyelonephritis is linked to long-term health risks for hypertension and chronic kidney disease. Androgen exposure increases susceptibility to, and severity of, uropathogenic Escherichia coli (UPEC) pyelonephritis and resultant scarring in both male and female mice, while anti-androgen therapy is protective against severe urinary tract infection (UTI) in these models. This work employed androgenized female C57BL/6 mice to elucidate the molecular mechanisms of post-infectious renal fibrosis and to determine how these pathways are altered by the presence of androgens. We found that elevated circulating testosterone levels primed the kidney for fibrosis by increasing local production of TGFß1 before the initiation of UTI, altering the ratio of transcription factors Smad2 and Smad3 and increasing the presence of mesenchymal stem cell (MSC)-like cells and Gli1 + activated myofibroblasts, the cells primarily responsible for deposition of scar components. Increased production of TGFß1 and aberrations in Smad2:Smad3 were maintained throughout the course of infection in the presence of androgen, correlating with renal scarring that was not observed in non-androgenized female mice. Pharmacologic inhibition of TGFß1 signaling blunted myofibroblast activation. We conclude that renal fibrosis after pyelonephritis is exacerbated by the presence of androgens and involves activation of the TGFß1 signaling cascade, leading to increases in cortical populations of MSC-like cells and the Gli1 + activated myofibroblasts that are responsible for scarring.

Evaluation of hematogenous spread and ascending infection in the pathogenesis of acute pyelonephritis due to group B streptococcus in mice.

Group B streptococcus (GBS) causes pyelonephritis in adults but the mechanisms of infection by which GBS infects the kidneys in vivo are unknown. We investigated GBS infection of the kidneys in mice following experimental challenge via the hematogenous route (transient bacteremia model) or transurethral route (bladder infection and cystitis model). Adult female mice were examined for bacterial dissemination to the kidneys and other organ systems at 24-72 h and tissue samples were assessed for histopathological changes. Comparisons included analysis of different challenge inoculum doses ranging between 107-109 CFU and investigation of several GBS serotypes, including representative strains of serotype V (NEM316), III (BM110, 874391) and Ia (807). Mice with transient, low-level GBS bacteremia routinely developed acute pyelonephritis secondary to high-level kidney infection; infection progressed with high GBS burdens that were sustained in the tissue for days in contrast to bacterial clearance in other organs, including spleen, liver and heart. The histopathological changes of acute pyelonephritis due to GBS were characterized using hematoxylin and eosin, and stains for bacteria, neutrophils, macrophages, mast cells and T lymphocytes; this revealed recruitment of a mixed inflammatory cell population that infiltrated the renal medulla of infected mice in focal areas of discrete micro-abscesses. In contrast, bladder infection leading to cystitis in mice did not result in ascending spread of GBS to the kidneys. We conclude that transient bacteremia, rather than preceding infection of the lower urinary tract, is the predominant condition that leads to GBS kidney infection and subsequent development of acute pyelonephritis.

Clinical Predictors Implicated in the Incidence of Acute Pyelonephritis during the Antepartum Period: A Population-Based Cohort Study.

INTRODUCTION: Acute pyelonephritis (APN) is a common infection during pregnancy that increases the risk of unfavorable maternal and fetal outcomes. However, it has not been clearly elucidated which demographic and clinical characteristics are associated with the incidence of APN during pregnancy. OBJECTIVE: This population-based cohort study aimed to determine the risk factors for APN during pregnancy. METHODS: Using the database of the Health Insurance Review and Assessment Service of South Korea, we enrolled Korean women who delivered infants between 2010 and 2014 in Korea and had complete health examination records within 1 year of pregnancy. We performed multivariate logistic regression analysis to evaluate the risk factors for APN during pregnancy. RESULTS: Of 370,248 women, 2,526 (0.7% of the total participants) were treated for APN while in hospitalization during pregnancy. Younger age, history of previous APN within 1 year of pregnancy, and abnormal results of health examination before pregnancy, such as high fasting glucose level (>100 mg/dL) and proteinuria, were associated with an increased risk of APN during pregnancy. CONCLUSION: Certain maternal demographic and clinical characteristics were associated with the incidence of APN during pregnancy, and these should be monitored closely during antenatal care.

ABILITY TO FORM BIOFILMS BY PYELONEPHRITIS CAUSATIVE AGENTS IN CHILDREN.

The work is dedicated to the study of biofilms formation process by main pyelonephritis causative agents in children in vitro using methods of light, fluorescent and scanning microscopy. To study biofilms formation bacteria were cultivated in liquid substratum on glass in polystyrene Petri dishes d=40mm. The study demonstrated that all isolates formed biofilms. Adhesion of bacteria planktonic forms took place on the first stage, intracellular matrix formation took place on the second stage, and biofilms formation took place on the third stage. During the study of E. coli and Proteus sрр bacteria preparations with the use of scanning and light microscopy ordered bacteria arrangement was seen in the form of separate structures or tiny clusters of bacterial cells united by matrix. During the study of the ability to form P. aeruginosa isolates biofilms with the help of scanning microscopy it was stated that the adhesion of separate bacterial cells occurs by conglomerates formation surrounded by matrix with further biofilms formation. Bacterial cells in the form of dense elongated sticks were seen under the film. P. аeruginosa isolates daily biofilms were stated to have dense structure in the form of gel. Packed biofilms areas with cells clusters with good fluorescence were found with the help of fluorescent microscopy. During daily K.рneumoniae isolates biofilms study by methods of scanning and fluorescent microscopy it was found that K.рneumoniae biofilms were covered with dense matrix and riddled with multiple canals in the form of apertures. During morphological peculiarities study of E. faecalis isolates biofilms formation with the use of scanning and fluorescent microscopy it was found that bacterial cells were densely packed and united by intracellular matrix under which bacteria of spherical shape were seen. Thus biofilms, the nature of which depends on the type of bacteria, are formed on the surface of conglomerates consisting of bacterial cells. Peculiarities of course and appearance of pyelonephritis chronic form and relapses in children is explained by biofilms formation.

Bilateral Pyelonephritis in a Cat with Multiple Urinary Malformations Including Ureteral Pseudodiverticulosis.

Ureteral pseudodiverticulosis is an unusual acquired abnormality in humans and dogs. This report describes the first feline case of ureteral pseudodiverticulosis, associated with right retrocaval ureter and malposition of the uretero-vesical junctions, in the context of pyelonephritis. The coexistence of pseudodiverticulosis with other urinary abnormalities suggested that this lesion should be considered in other patients with urinary pathology.