Two Cases of Acute Focal Bacterial Nephritis With Central Nervous System Manifestations in Children and Literature Review.

Acute focal bacterial nephritis (AFBN) is a kidney disease characterized by a localized bacterial infection that manifests as an inflammatory mass. Most children with AFBN have nonspecific symptoms including fever, vomiting, and abdominal discomfort, and some develop neurological symptoms such as meningeal irritation, unconsciousness, and seizures as their condition worsens. This was 2 cases of AFBN with central nervous system manifestations in children, and we analyzed its possible mechanisms of the clinical and radiographic features. We experience 2 very unusual cases of AFBN which were linked to central nervous system abnormalities. A 6-year-old boy with AFBN and clinically moderate ncephalitis/encephalopathy with a reversible splenial lesion (MERS) presented with neurological symptoms, including unconsciousness and convulsions. The second case involved an 8-year-old child with AFBN-associated acute encephalopathy who exhibited neurological symptoms, including unconsciousness. According to previous research, AFBN is linked to central nervous system impairment. As a result, when a clinician meets a patient with an inexplicable fever caused by a neurological condition, he should pay attention to this diagnosis of AFBN and follow it in the abdominal graph.

Skin-to-Renal Pelvis Distance Predicts Costovertebral Angle Tenderness in Adult Patients with Acute Focal Bacterial Nephritis.

OBJECTIVES: The aim of this study was to examine whether the distance between the skin and the renal pelvis affects the detection of costovertebral angle (CVA) tenderness in patients with acute focal bacterial nephritis (AFBN). METHODS: We retrospectively reviewed the charts of our patients between April 2013 and June 2019 who were diagnosed as having AFBN. Diagnosis was based on ultrasound or computed tomography with contrast, revealing at least one wedge-shaped area of decreased vascularity and confirmation of fever not attributable to another condition. RESULTS: We extracted 23 cases, all Japanese (mean age 60.0 years old [range 45-81 years], 7 males, 16 females). CVA tenderness was present in 8 of these 23 patients. Receiver operating characteristic curves were drawn to evaluate the ability to differentiate skin-to-renal pelvis distance (SPD), body mass index, and age. Only SPD was a useful predictor of CVA tenderness, and 66 mm was determined as the optimal cutoff point (area under the receiver operating characteristic curve 0.858, 95% confidence interval 0.70-1.00). Logistic regression analysis was performed with CVA tenderness as a dependent variable, and SPD, body mass index, and age as explanatory variables. SPD was an independent predictive variable of CVA tenderness (P = 0.038, odds ratio 0.76, 95% confidence interval 0.590-0.986). CONCLUSIONS: CVA tenderness showed low yield in the diagnosis of AFBN in patients with longer SPD. Its use for diagnosis in obese patients may therefore be limited.

A Case of Acute Encephalopathy Associated with Acute Focal Bacterial Nephritis.

Acute encephalopathy is a syndrome characterized by an acute onset of disturbance of consciousness. Many acute encephalopathies are caused by viral infections; however, they can also be a result of bacterial infections. Acute focal bacterial nephritis (AFBN) can cause neurological symptoms, such as irritation, unconsciousness, and seizures. In some cases, AFBN-associated acute encephalopathy has also been reported. This report describes the first case of acute encephalopathy with AFBN without significant findings on brain MRI. The patient was a 3-year-old male, who had two episodes of febrile seizures at the ages of 1 and 2 years. He developed disturbance of consciousness, irritability, excitability, and neck stiffness on the day after admission. There were no abnormal findings on brain MRI; however, a generalized high-voltage slow wave was noted on electroencephalography (EEG). His urinary sediment count was elevated, and Morganella morganii and Enterococcus faecalis were detected in the urinary culture. A diagnosis of acute encephalopathy with urinary tract infection (UTI) was made. Intravenous (IV) antibiotics were administered to treat the UTI, while methylprednisolone pulse therapy and IV immunoglobulin were administered to treat acute encephalopathy. Additionally, AFBN was detected in both kidneys on contrast-enhanced CT. The patient received a second course of methylprednisolone pulse therapy due to the persistent high voltage slow wave noted on the EEG on day 8. Furthermore, contrast-enhanced CT revealed AFBN in both kidneys. The final diagnosis was acute encephalopathy with AFBN; however, we had initially diagnosed febrile seizures associated with UTI. It should be noted that acute encephalopathy is associated with AFBN.

Acute focal bacterial nephritis and prolonged fever.

Acute focal bacterial nephritis (AFBN) is characterised by a complicated upper urinary tract infection ranging from acute pyelonephritis to renal abscess. Timely diagnosis of AFBN is important because antibiotic therapy of longer duration is required. A 10-year-old boy presented with fever for 5 days and bilateral flank pain. He was oriented and cooperative but appeared ill. Physical examination did not reveal any oedema or costovertebral angle tenderness. Acute phase reactants such as erythrocyte sedimentation rate and C-reactive protein were raised, serum creatinine was 1.25 mg/dL (0.31-0.88) and leucocyte esterase was positive in the urine. Ultrasonographic examination demonstrated bilaterally enlarged kidneys with increased echogenicity. Because of the high creatinine level, abdominal magnetic resonance imaging (MRI) was performed instead of computed tomography (CT) for further evaluation. The MRI showed an increase in the size of both kidneys, renal cortical heterogeneity and multiple cortical nodular lesions with diffusion restriction (constrained Brownian movement of water molecules) on diffusion-weighted MRI. A negative urine culture result in children presenting with fever and abdominal pain may mislead the clinicians, causing them to miss a nephro-urological diagnosis. It is therefore recommended that patients in whom the cause of fever cannot be determined be scanned by ultrasound and examined by CT or MRI so that undiagnosed and/or suspected cases of AFBN might be detected.

Administration of Lactobacillus reuteri Combined with Clostridium butyricum Attenuates Cisplatin-Induced Renal Damage by Gut Microbiota Reconstitution, Increasing Butyric Acid Production, and Suppressing Renal Inflammation.

Cisplatin-induced nephrotoxicity is associated with gut microbiota disturbance. The present study aimed to investigate whether supplementation of Lactobacillus reuteri and Clostridium butyricum (LCs) had a protective effect on cisplatin-induced nephrotoxicity through reconstruction of gut microbiota. Wistar rats were given different treatments: control, cisplatin (Cis), cisplatin + C. butyricum and L. reuteri (Cis+LCs), and C. butyricum and L. reuteri (LCs). We observed that cisplatin-treated rats supplemented with LCs exhibited significantly decreased renal inflammation (KIM-1, F4/80, and MPO), oxidative stress, fibrosis (collagen IV, fibronectin, and a-SMA), apoptosis, concentration of blood endotoxin and indoxyl sulfate, and increased fecal butyric acid production compared with those without supplementation. In addition, LCs improved the cisplatin-induced microbiome dysbiosis by maintaining a healthy gut microbiota structure and diversity; depleting Escherichia-Shigella and the Enterobacteriaceae family; and enriching probiotic Bifidobacterium, Ruminococcaceae, Ruminiclostridium_9, and Oscillibacter. Moreover, the LCs intervention alleviated the cisplatin-induced intestinal epithelial barrier impairment. This study indicated LCs probiotic serves as a mediator of the gut-kidney axis in cisplatin-induced nephrotoxicity to restore the intestinal microbiota composition, thereby suppressing uremic toxin production and enhancing butyrate production. Furthermore, the renoprotective effect of LCs is partially mediated by increasing the anti-inflammatory effects and maintaining the integrity of the intestinal barrier.

Diagnosis and Treatment for Acute Focal Bacterial Nephritis With Renal Abscess Based on Magnetic Resonance Imaging Evaluation.

A 5-year-old boy was diagnosed with left acute focal bacterial nephritis (AFBN) complicated with renal abscess (RA) on magnetic resonance imaging (MRI). MRI is useful for diagnosing AFBN and RA complications. He was administered antibiotics for 3 weeks on evaluation of MRI findings. Evaluation of apparent diffusion coefficient values over time may be useful as an index of treatment of RA.

Sex Differences in Population Dynamics during Formation of Kidney Bacterial Communities by Uropathogenic Escherichia coli.

Uropathogenic Escherichia coli (UPEC), the primary etiologic agent of urinary tract infections (UTIs), encounters a restrictive population bottleneck within the female mammalian bladder. Its genetic diversity is restricted during establishment of cystitis because successful UPEC must invade superficial bladder epithelial cells prior to forming clonal intracellular bacterial communities (IBCs). In this study, we aimed to understand UPEC population dynamics during ascending pyelonephritis, namely, formation of kidney bacterial communities (KBCs) in the renal tubular lumen and nucleation of renal abscesses. We inoculated the bladders of both male and female C3H/HeN mice, a background which features vesicoureteral reflux; we have previously shown that in this model, males develop severe, high-titer pyelonephritis and renal abscesses much more frequently than females. Mice were infected with 40 isogenic, PCR-tagged ("barcoded") UPEC strains, and tags remaining in bladder and kidneys were ascertained at intervals following infection. In contrast to females, males maintained a majority of strains within both the bladder and kidneys throughout the course of infection, indicating only a modest host-imposed bottleneck on overall population diversity during successful renal infection. Moreover, the diverse population in the infected male kidneys obscured any restrictive bottleneck in the male bladder. Finally, using RNA in situ hybridization following mixed infections with isogenic UPEC bearing distinct markers, we found that despite their extracellular location (in the urinary space), KBCs are clonal in origin. This finding indicates that even with bulk reflux of infected bladder urine into the renal pelvis, successful ascension of UPEC to establish the tubular niche is an uncommon event.

Detection of Frederiksenia sp. isolated from a cat with nephritis - Short communication.

In this paper we report the phenotypic and partial genetic characterisation of a novel bacterium strain isolated from a cat with severe nephritis. Multilocus sequence analysis was performed on the 16S rRNA and three housekeeping (recN, rpoB, infB) gene sequences obtained by PCR. In accordance with the results of phenotypic tests, the phylogenetic analyses confirmed the relatedness of the new strain (6036) to the family Pasteurellaceae. On the phylogenetic trees, strain 6036 appeared in a separate branch, closest to that of the type species (Frederiksenia canicola) of the genus Frederiksenia. These two bacteria shared 95.14 and 76.88% identity in their partial 16S rRNA and recN gene sequences, respectively. The rpoB- and infB-based phylogenetic analyses indicated that strain 6036 is most closely related to Bibersteinia trehalosi (with 90.58% identity) and [Haemophilus] felis ATCC 49733 (89.50% identity), respectively. The predicted genome identity values, based on the recN gene sequences, suggested that strain 6036 can be classified into the genus Frederiksenia as a novel species. A PCR method, specific to strain 6036, was developed to allow its rapid and accurate identification and differentiation from F. canicola and other species of Pasteurellaceae. The minimal inhibitory concentrations of 18 antimicrobial agents for strain 6036 were also determined.

Marcadores predictivos de nefritis focal bacteriana aguda. Estudio multicéntrico casos-control / Predictive markers of acute focal bacterial nephritis. A multicentre case-control study

INTRODUCCIÓN: La nefritis focal bacteriana aguda es una infección intersticial bacteriana, localizada en el parénquima renal, que entraña mayor gravedad que la pielonefritis aguda. El objetivo del estudio es el análisis de factores predictivos que permitan su diagnóstico precoz, fundamental para un adecuado abordaje terapéutico. PACIENTES Y MÉTODOS: Estudio multicéntrico de casos y control retrospectivo. Centros participantes: hospitales de Castellón y Valencia. Periodo de estudio: 2010-2018. Casos: nefritis focal bacteriana. Controles: pielonefritis aguda. RESULTADOS: Se incluyó a un total de 158 pacientes (1:1). La mediana de edad de los casos fue 2 años. El 75% de sexo femenino. No existieron diferencias en la presentación clínica. En el análisis univariante la nefritis focal se relacionó con malformaciones del tracto urinario, bacteriemia, recuento de neutrófilos y la procalcitonina, así como las convulsiones febriles en el límite de la significación. Valores de procalcitonina ≥ 2 ng/ml tiene una OR de 4,9 (IC del 95: 1,77-13,85) de presentar nefritis focal. En el análisis multivariante las malformaciones urológicas mantuvieron la significación estadística y la procalcitonina en el límite de la significación. CONCLUSIONES: Las malformaciones del tracto urinario predisponen al desarrollo de nefritis focal bacteriana. Ante pacientes con infección del tracto urinario y factores predictivos de nefritis focal bacteriana aguda, sería recomendable la realización de una ecografía Doppler renal en fase aguda para un diagnóstico y un tratamiento adecuado

INTRODUCTION: Acute focal bacterial nephritis is an interstitial bacterial infection, localised in the renal parenchyma, which can be more serious than acute pyelonephritis. The aim of this study is the analysis of predictive factors that may lead to its early diagnosis, which is essential for an adequate therapeutic approach. PATIENTS AND METHODS: A retrospective, multicentre case and control study. The participant centres were hospitals in Castellon and Valencia. The study period was 2010-2018, with the cases being patients with focal bacterial nephritis and the patients with pyelonephritis as controls. RESULTS: A total of 158 (1:1) patients were included. The median age of the cases was 2 years and there were 75% females. There were no differences in the clinical presentation. In the univariate analysis, focal nephritis was associated with malformations of the urinary tract, bacteraemia, the neutrophil count, and procalcitonin, as well as febrile convulsions of borderline significance. Procalcitonin values ≥ 2 ng/ml had an OR of 4.9 (95% CI; 1.77-13.85) of presenting with focal nephritis. In the multivariate analysis, the urological malformations still maintained statistical significance and borderline significance for procalcitonin. CONCLUSIONS: The urinary tract malformations predispose the development of focal bacterial nephritis. In patients with a urinary tract infection and predictive factors of acute focal bacterial nephritis it would be worthwhile performing a renal Doppler ultrasound in the acute phase for its appropriate diagnosis and treatment

Comparison of imaging findings between acute focal bacterial nephritis (acute lobar nephronia) and acute pyelonephritis: a preliminary evaluation of the sufficiency of ultrasound for the diagnosis of acute focal bacterial nephritis.

OBJECTIVE: The recommended durations of treatment for acute focal bacterial nephritis (AFBN) and acute pyelonephritis (APN) are different. This study aimed to clarify the sonographic findings used to differentiate AFBN from APN during diagnosis and to compare these findings with those obtained using computed tomography (CT). METHODS: Eleven children with urinary tract infection who underwent contrast-enhanced CT and ultrasound examinations within a 24-h period were included. Diagnoses of AFBN and APN were established using CT data as the gold standard; viz., a focal area of poor enhancement is observed in AFBN but not in APN. The following ultrasound findings were evaluated: focal loss of corticomedullary differentiation (one/multiple), focal hyperechogenicity, abscess formation, and diffuse nephromegaly. Fisher's exact test was used for statistical analysis. RESULTS: Of the 11 patients, 8 had AFBN and 3 had APN. The two groups differed significantly in the incidence of a focal loss of corticomedullary differentiation (present/absent, 8/8 vs. 0/3; p = 0.01) but not in the incidence of focal hyperechogenicity, abscess formation, and diffuse nephromegaly (present/absent, 2/8 vs. 0/3, p > 0.99; 1/8 vs. 0/3, p > 0.99; and 5/8 vs. 3/3, p = 0.49, respectively). The poorly enhanced area used to diagnose AFBN on CT images appeared as a focal loss of corticomedullary differentiation in ultrasound examinations. CT revealed multiple lesions in two cases in which ultrasound revealed only single lesions. CONCLUSION: In our small cohort, ultrasound could be adequately used to diagnose AFBN based on the presence of a focal loss of corticomedullary differentiation. CT may not be required to differentiate AFBN from APN.

[Predictive markers of acute focal bacterial nephritis. A multicentre case-control study]. / Marcadores predictivos de nefritis focal bacteriana aguda. Estudio multicéntrico casos-control.

INTRODUCTION: Acute focal bacterial nephritis is an interstitial bacterial infection, localised in the renal parenchyma, which can be more serious than acute pyelonephritis. The aim of this study is the analysis of predictive factors that may lead to its early diagnosis, which is essential for an adequate therapeutic approach. PATIENTS AND METHODS: A retrospective, multicentre case and control study. The participant centres were hospitals in Castellon and Valencia. The study period was 2010-2018, with the cases being patients with focal bacterial nephritis and the patients with pyelonephritis as controls. RESULTS: A total of 158 (1:1) patients were included. The median age of the cases was 2 years and there were 75% females. There were no differences in the clinical presentation. In the univariate analysis, focal nephritis was associated with malformations of the urinary tract, bacteraemia, the neutrophil count, and procalcitonin, as well as febrile convulsions of borderline significance. Procalcitonin values ≥2 ng/ml had an OR of 4.9 (95%CI; 1.77-13.85) of presenting with focal nephritis. In the multivariate analysis, the urological malformations still maintained statistical significance and borderline significance for procalcitonin. CONCLUSIONS: The urinary tract malformations predispose the development of focal bacterial nephritis. In patients with a urinary tract infection and predictive factors of acute focal bacterial nephritis it would be worthwhile performing a renal Doppler ultrasound in the acute phase for its appropriate diagnosis and treatment.

Protective effects of tuna meat oligopeptides (TMOP) supplementation on hyperuricemia and associated renal inflammation mediated by gut microbiota.

Recently, interest in using whole food-derived mixtures to alleviate chronic metabolic syndrome through potential synergistic interactions among different components is increasing. In this study, the effects and mechanisms of tuna meat oligopeptides (TMOP) on hyperuricemia and associated renal inflammation were investigated in mice. Dietary administration of TMOP alleviated hyperuricemia and renal inflammation phenotypes, reprogramed uric acid metabolism pathways, inhibited the activation of NLRP3 inflammasome and TLR4/MyD88/NF-κB signaling pathways, and suppressed the phosphorylation of p65-NF-κB. In addition, TMOP treatments repaired the intestinal epithelial barrier, reversed the gut microbiota dysbiosis and increased the production of short-chain fatty acids. Moreover, the antihyperuricemia effects of TMOP were transmissible by transplanting the fecal microbiota from TMOP-treated mice, indicating that the protective effects were at least partially mediated by the gut microbiota. Thus, for the first time, we clarify the potential effects of TMOP as a whole food derived ingredient on alleviating hyperuricemia and renal inflammation in mice, and additional efforts are needed to confirm the beneficial effects of TMOP on humans.

The route of infection with Leptospira interrogans serovar Copenhageni affects the kinetics of bacterial dissemination and kidney colonization.

The goal of this study was to characterize how natural routes of infection affect the kinetics of pathogenic Leptospira dissemination to blood and kidney. C3H/HeJ mice were sublethally infected with L. interrogans serovar Copenhageni FioCruz L1-130 (Leptospira) through exposure of a dermis wound and through oral and nasal mucosa, in comparison to uninfected mice and to mice infected via standard intraperitoneal inoculation. In striking contrast to oral mucosa inoculation, transdermal and nasal mucosa infections led to weight loss, renal colonization and inflammation, as previously observed for conjunctival and intraperitoneal infections. However, the timing at which Leptospira gained access to blood, as well as Leptospira' colonization of the kidney and shedding in urine, differed from intraperitoneal infection. Furthermore, a comparative analysis of transcription of pro-inflammatory mediators in kidney and total immunoglobulin isotyping in serum from infected mice, showed increased innate immune response markers (KC, MIP-2, TNF-α) and lower Th1 associated IFN-γ in kidney, as well as lower Th1 associated IgG2a in mice infected through the nasal mucosa as compared to intraperitoneal infection. We conclude that the route of infection affects the timing at which Leptospira gains access to blood for dissemination, as well as the dynamics of colonization and inflammation of the kidney.

Comparison of mild encephalopathy with reversible splenial lesion with and without acute focal bacterial nephritis.

OBJECTIVE: Clinically mild encephalitis/encephalopathy with a reversible lesion (MERS) is characterized by reversible lesions with transiently-reduced diffusion in the splenium of the corpus callosum on magnetic resonance imaging. Recently, cases of MERS with accompanying acute focal bacterial nephritis (AFBN) have been reported in children. This study aimed to clarify the clinical features of MERS with AFBN. METHODS: A retrospective study of patients with MERS was conducted at Nagano Children's Hospital, Japan, from April 2013 to March 2018. The clinical signs and laboratory findings of MERS patients with AFBN (AFBN group) and without AFBN (non-AFBN group) were measured and compared. RESULTS: Of 12 patients diagnosed as having MERS, 3 were also found to have AFBN. Seven of the 9 patients without AFBN were associated with infectious agents, including rotavirus and influenza viruses. No patient received steroids or intravenous immunoglobulin therapy, and none displayed neurological sequelae. Serum C-reactive protein (CRP) levels were significantly higher in the AFBN group than in the non-AFBN group (14.7 mg/dL versus 0.8 mg/dL, P = 0.009). AFBN group patients were also significantly older (97 months versus 27 months, P = 0.018) and experienced significantly less frequent seizures (33% versus 100%, P = 0.045). The mean duration of neurological symptoms was significantly longer in the AFBN group than in the non-AFBN group (4 days versus 1.7 days, P = 0.013). CONCLUSIONS: Pediatric patients with AFBN often present with non-specific findings, such as fever and abdominal pain. Pediatricians should be aware of the possibility of AFBN in the clinical setting of MERS, particularly when the patient exhibits inexplicably high CRP.

Non-invasive discrimination of acute focal bacterial nephritis with pyelonephritis.

BACKGROUND: The appropriate antimicrobial treatment period for febrile urinary tract infection (UTI) can be changed, depending on whether the patient has acute focal bacterial nephritis (AFBN). The aim of this study was to clarify the characteristics of AFBN compared with those of acute pyelonephritis (APN) and establish a strategy to detect AFBN. METHODS: A total of 77 patients diagnosed with febrile UTI were enrolled. They were divided into APN (n = 64) and AFBN groups (n = 13). The clinical data and other laboratory biomarkers were retrospectively analyzed. RESULTS: The time required for fever resolution after antimicrobial treatment was significantly longer in the AFBN group than in the APN group (2.77 days vs 1.11 days, respectively, P < 0.001). Also, the time to disappearance of pyuria after antimicrobial treatment was longer in the AFBN group than in the APN group (6.22 days vs 2.32 days, respectively, P = 0.001). Fever lasting >1.75 days after antimicrobial treatment had a sensitivity of 92% and specificity of 79% for the detection of AFBN, while pyuria disappearance after 4 days had a sensitivity of 88% and specificity of 85%. When patients fulfilled both cut-offs, the sensitivity and specificity were 89% and 97%. CONCLUSION: Acute focal bacterial nephritis was associated with fever of significantly longer duration after antimicrobial treatment, and it took a longer time for pyuria to disappear. Children with febrile UTI should be evaluated for AFBN if the fever persists ≥48 h after the initiation of antimicrobial treatment and if pyuria lasts for 4 days.