Encrusted Urinary Tract Infections Due to Corynebacteria Species

[Emergent presence of slow-growing microorganisms in urine cultures. Clinical and microbiological analysis]

INTRODUCTION

The prevalence, clinical characteristics, and antibiotic susceptibility of the slow-growing microorganisms Corynebacterium urealyticum, Corynebacterium glucuronolyticum, Lactobacillus delbrueckii, and Aerococcus spp. in urine cultures are analyzed.

MATERIAL AND METHODS

Descriptive and retrospective cross-sectional study carried out in a Regional Hospital. Reports of clinical episodes with single isolation of the aforementioned microorganisms were selected between January 2016 and December 2023.

RESULTS

A total of 186 single-isolation episodes were included, corresponding to 0.44% of the total. The most frequently isolated species was Aerococcus urinae. Overall, the risk factors were the presence of an indwelling bladder catheter (24.73%), immunosuppression (24.19%), health care (35.48%), diabetes mellitus (19.89%), nephrourological disorders (31.18%) and previous antibiotherapy (35.48%). Urinary tract infections due to Aerococcus spp. predominated in elderly patients, with nephrourological disorders and a history of antibiotic therapy in the previous 3 months. C. glucuronolyticum, C. urealyticum and L. delbrueckii were associated with immunosuppression, healthcare contact and previous antibiotherapy. C. urealyticum was also associated with the presence of an indwelling bladder catheter.

CONCLUSIONS

Slow-growing opportunistic emerging microorganisms represent a small percentage of the aetiological agents in urinary tract infections, although of important and growing clinical interest given their pathogenic role in the presence of certain circumstances and risk factors, as well as the challenges they pose for laboratory diagnosis. It is essential to perform antibiograms for an adequate targeted treatment.

Encrusted pyelitis and hyperammonemia due to Corynebacterium urealyticum in a kidney transplant recipient

INTRODUCTION

The bacterium Corynebacterium urealyticum produces urease and can cause encrusted pyelitis, a condition characterized by calcifications of the renal pelvis and ureteral wall, which may obstruct the urinary tract. We describe a case of encrusted pyelitis caused by C. urealyticum in a kidney transplant patient presenting with altered consciousness due to hyperammonemia.

CASE PRESENTATION

An 81-year-old woman with a history of cadaveric kidney transplantation, thirty years prior, presented with acute altered consciousness during hospitalization. Laboratory findings showed acute renal failure and hyperammonemia, and urinalysis revealed high pH (>9.0) and pyuria. Abdominal non-contrast computed tomography revealed calcification of the renal pelvis and hydronephrosis. C. urealyticum was isolated from both blood and urine cultures. A diagnosis of encrusted pyelitis and hyperammonemia caused by C. urealyticum was made, and intravenous vancomycin was administered. Following the initiation of vancomycin and the temporary hemodialysis, her hyperammonemia and altered consciousness rapidly improved. Treatment with vancomycin resulted in a reduction of the urinary tract encrustation.

CONCLUSION

This case highlights C. urealyticum as a urinary pathogen that can lead to encrusted pyelitis, hyperammonemia, and altered consciousness in renal transplant patients.

Population Pharmacokinetic/Pharmacodynamic Study of Linezolid in Hospital-Acquired Pneumonia Patients with Renal Insufficiency

Purpose

The optimal treatment strategy in patients with hospital-acquired pneumonia (HAP) due to Gram-positive bacteria and renal insufficiency remains challenging. The objective of this study was to compare the outcomes of linezolid versus teicoplanin in HAP patients with renal insufficiency and to explore optimal dosage strategy for linezolid.

Methods

The retrospective study enrolled adult patients treated with intravenous linezolid or teicoplanin at Suzhou Municipal Hospital between July 2018 and August 2023. For the comparative pharmacodynamic study, effectiveness, safety and target attainment of trough concentration (Cmin) for teicoplanin versus linezolid treatment in HAP patients with document Gram-positive bacteria and renal insufficiency were compared. For the population pharmacokinetics (PPK) analyses, linezolid concentrations collected exclusively from HAP patients with renal insufficiency were used and the optimal dosage strategy was investigated using Monte Carlo simulations.

Results

Linezolid-treated patients had a higher bacterial eradication rate than teicoplanin-treated patients (88.5% vs 63.4%, P < 0.001). A higher proportion of patients in the linezolid group experienced at least one adverse reaction (42.0% vs 25.0%, P = 0.025). Significantly more supratherapeutic Cmin, less therapeutic Cmin were achieved in the linezolid group (adjusted P < 0.05). A total of 207 linezolid concentrations from 166 patients with renal insufficiency were available for the PPK analysis. Age and creatinine clearance (CrCL) were identified as significant covariates that influenced clearance. Simulations show that 300 mg q12h provide the optimal exposure in patients with a CrCL of 60 or 45 mL/min, and 200 mg q12h was recommended for patients with a CrCL of 30 or 15 mL/min.

Conclusion

Linezolid-treated patients with HAP and renal insufficiency had higher bacterial eradication rates, supratherapeutic exposure and adverse reactions than teicoplanin-treated patients. Linezolid dose reduction in patients with renal insufficiency improved the probability of achieving optimal exposure.

The Role of the Urobiome in Kidney Transplantation: A Systematic Review

Background

The urinary microbiome, also known as the urobiome, was traditionally considered sterile. However, emerging evidence suggests its presence in the urinary tract. Urobiome dysbiosis has been associated with various urologic conditions, making it a topic of interest also in kidney transplantation. This systematic review examines the evidence of urobiome changes in kidney transplant recipients (KTRs).

Methods

Systematic literature searches in the PubMed and SCOPUS databases.

Results

Of the 770 articles identified, 8 met the inclusion criteria. The urobiome showed reduced diversity in KTRs compared with healthy controls and patients on dialysis. Proteobacteria enrichment was associated with graft stability or spontaneous tolerance in KTRs without immunological events. Kidney interstitial fibrosis and tubular atrophy were associated with changes in resident urinary microbes and increased pathogenic bacteria. Additionally, KTRs with chronic allograft dysfunction had a higher prevalence of Corynebacterium.

Conclusions

The review highlights the importance of studying the urobiome in KTRs and its potential impact on transplant outcomes. The field remains largely unexplored, and further research is needed to establish consistent study designs and objectives. Future studies could lead to biomarker discovery, personalized therapies, and improved outcomes and graft survival in KTRs.

Diptheroids can cause nosocomial UTI and be multidrug resistant: A case report of Corynebacterium striatum, first from India

Gram positive bacilli in the urine are usually dismissed as contaminants in urine specimens as these are commensal flora of skin and mucous membranes. Corynebacterium species were misidentified in the past due to complex biochemicals but the advent of modern diagnostics has made their identification quicker and accurate. Corynebacterium species have recently emerged as pathogens of nosocomial outbreak potential. C. striatum has been identified as opportunistic nosocomial pathogen causing various infections. We report first case of C. striatum as nosocomial urinary tract infection (UTI) pathogen in a child with bilateral renal disease. C. striatum causing UTI is very rarely reported.

Nanotechnology Involved in Treating Urinary Tract Infections: An Overview

Considered as the most frequent contaminations that do not require hospitalization, urinary tract infections (UTIs) are largely known to cause significant personal burdens on patients. Although UTIs overall are highly preventable health issues, the recourse to antibiotics as drug treatments for these infections is a worryingly spread approach that should be addressed and gradually overcome in a contemporary, modernized healthcare system. With a virtually alarming global rise of antibiotic resistance overall, nanotechnologies may prove to be the much-needed 'lifebuoy' that will eventually suppress this prejudicial phenomenon. This review aims to present the most promising, currently known nano-solutions, with glimpses on clinical and epidemiological aspects of the UTIs, prospective diagnostic instruments, and non-antibiotic treatments, all of these engulfed in a comprehensive overview.

Astragaloside IV improves the pharmacokinetics of febuxostat in rats with hyperuricemic nephropathy by regulating urea metabolism in gut microbiota

Hyperuricemic nephropathy (HN) is a common clinical complication of hyperuricemia. The pathogenesis of HN is directly related to urea metabolism in the gut microbiota. Febuxostat, a potent xanthine oxidase inhibitor, is the first-line drug used for the treatment of hyperuricemia. However, there have been few studies on the pharmacokinetics of febuxostat in HN animal models or in patients. In this study, a high-purine diet-induced HN rat model was established. The pharmacokinetics of febuxostat in HN rats was evaluated using LC-MS/MS. Astragaloside IV (AST) was used to correct the abnormal pharmacokinetics of febuxostat. Gut microbiota diversity analysis was used to evaluate the effect of AST on gut microbiota. The results showed that the delayed elimination of febuxostat caused drug accumulation after multiple administrations. Oral but not i. p. AST improved the pharmacokinetics of febuxostat in HN rats. The mechanistic study showed that AST could regulate urea metabolism in faeces and attenuate urea-ammonia liver-intestine circulation. Urease-related genera, including Eubacterium, Parabacteroides, Ruminococcus, and Clostridia, decreased after AST prevention. In addition, the decrease in pathogenic genera and increase in short-chain fatty acids (SCFA) producing genera also contribute to renal function recovery. In summary, AST improved the pharmacokinetics of febuxostat in HN rats by comprehensive regulation of the gut microbiota, including urea metabolism, anti-calcification, and short-chain fatty acid generation. These results imply that febuxostat might accumulate in HN patients, and AST could reverse the accumulation through gut microbiota regulation.

Endoscopic treatment of urothelial encrusted pyelo-ureteritis disease: A case series

BACKGROUND

Urothelial encrusted pyelo-ureteritis disease is an infrequent condition and there is no unified surgical treatment and reference standard to consult. We have used a minimally invasive endoscopic method to treat three such cases, which yielded excellent results.

CASE SUMMARY

The first case was a 45-year-old man who had unilateral ureteropelvic junction (UPJ) atresia and contralateral stenosis and was treated by double endoscopic surgery using an anterograde percutaneous nephroscope coupled with a rigid retrograde ureteroscope. The second case was a 12-year-old boy who received a percutaneous nephroscopy on one side and a percutaneous nephroscopy with a rigid ureteroscope on the other side due to the presence of bilateral UPJ stenosis. The third case was a 32-year-old woman with bilateral lower ureteral stricture treated using a rigid retrograde ureteroscope. Endoscopic surgeries were successfully performed on all the three patients. Varying degrees of encrustation and erosion of the urothelium were observed during the operation. The calcified layer composition analysis showed magnesium ammonium phosphate or carbonate apatite. Two patients achieved a good prognosis.

CONCLUSION

Minimally invasive endoscopic treatment for urothelial encrusted pyelo-ureteritis disease can yield better results.

Encrusted Uretero-Pyelitis Caused by Corynebacterium urealyticum: Case Report and Literature Review

We report the case of a 70-year-old female patient with solitary functioning left kidney and encrusted uretero-pyelitis caused by Corynebacterium urealyticum, which was treated by antibiotic therapy and oral acidification with L-methionine. We review the literature for similarly reported cases.

Mechanisms of Zhenwu decoction for the treatment of renal fibrosis at various stages: What is the role of Corynebacterium?

Many studies demonstrated that Zhenwu decoction (ZWD) is effective in the treatment of kidney fibrosis, whereas the mechanism remains unclear. In this work, a microbiomics-based strategy was used to investigate the mechanism of protective effects of ZWD on kidney fibrosis. Unilateral ureteral obstruction was used to replicate a rat model of renal fibrosis, and rats were divided into prophylactic, early, and progression stages according to the timing of administration. Feces was collected to perform microbiota evaluation by high-throughput 16S DNA sequencing. The results indicated that Corynebacterium, Alistipes, Dorea, and Lactonifactor were highlighted as key targeted flora of ZWD in the treatment of renal fibrosis, and their biological functions were related to inflammation, immunity, and renal excretion. Especially, Corynebacterium presented a significant positive correlation with the concentration of Cys-C, Scr, and BUN. The studies on the changes in inflammatory cytokines (INF-γ, IL-1β, IL-4, and TNF-α) and immunoglobulin (IgA, IgM, and IgG) confirmed the beneficial effects of ZWD on kidney fibrosis. Therefore, this study confirmed the protective effect of ZWD against renal fibrosis at various disease stages, and its mechanism was associated with re-establishing dysbiosis of the intestinal microbiota, reducing inflammation, as well as regulating immune functions. In particular, Corynebacterium may be a key flora in the treatment of renal fibrosis.