The global burden of antimicrobial resistance - urinary tract infections

Antimicrobial resistance (AMR) has emerged as a significant global healthcare problem. Antibiotic use has accelerated the physiologic process of AMR, particularly in Gram-negative pathogens. Urinary tract infections (UTIs) are predominantly of a Gram-negative nature. Uropathogens are evolutionarily highly adapted and selected strains with specific virulence factors, suggesting common mechanisms in how bacterial cells acquire virulence and AMR factors. The simultaneous increase in resistance and virulence is a complex and context-dependent phenomenon. Among known AMR mechanisms, the plenitude of different β-lactamases is especially prominent. The risk for AMR in UTIs varies in different patient populations. A history of antibiotic consumption and the physiology of urinary flow are major factors that shape AMR prevalence. The urinary tract is in close crosstalk with the microbiome of other compartments, including the gut and genital tracts. In addition, pharmacokinetic properties and the physiochemical composition of urinary compartments can contribute to the emergence of AMR. Alternatives to antibiotic treatment and a broader approach to address bacterial infections are needed. Among the various alternatives studied, antimicrobial peptides and bacteriophage treatment appear to be highly promising approaches. We herein summarize the present knowledge of clinical and microbiological AMR in UTIs and discuss innovative approaches, namely new risk prediction tools and the use of non-antibiotic approaches to defend against uropathogenic microbes.

Advances in the pharmacological management of bacterial peritonitis

Introduction: Bacterial peritonitis is an infection with high mortality if not treated immediately. In the absence of an intraabdominal source of infection, bacterial peritonitis may arise in patients with liver cirrhosis, in patients on peritoneal dialysis (PD) for end-stage renal disease or in patients with tuberculosis. In patients with cirrhosis, bacterial peritonitis may trigger acute on chronic liver failure with substantial mortality despite optimal treatment. In patients on PD, peritonitis may make continuation of PD impossible, necessitating the switch to hemodialysis.Areas covered: Recovery from peritonitis and prevention of complications depend on timely pharmacological management. Challenges are the broad microbiological spectrum with growing rates of antimicrobial resistance, the underlying chronic liver or kidney failure and high rates of relapse. The authors provide a review of predisposing conditions, diagnosis, and prevention of bacterial peritonitis with a particular focus on the pharmacological management.Expert opinion: Diagnosis of the type of bacterial peritonitis is essential to pharmacological management. In patients with spontaneous bacterial peritonitis, broad-spectrum antibiotics should be given intravenously in conjunction with albumin. In patients on PD, antibiotic therapy should be preferably applied intraperitoneally with empirical coverage of gram-positive and gram-negative bacteria. Secondary peritonitis usually requires surgical or interventional treatment.

P1608CXCL13 IS STRONGLY INDUCED BY RENAL ISCHEMIA REPERFUSION INJURY AND CORRELATES WITH SEVERITY OF RENAL INFLAMMATION

Background and Aims

Ischemia reperfusion injury (IRI) is a strong trigger of inflammation and is tightly linked to renal allograft damage and function. CXCL13 or B lymphocyte chemoattractant (BLC) is a chemokine that controls B cell organization in lymphoid tissues and has recently been described as a biomarker for B cell involvement in acute kidney allograft rejection.

Method

To show, that CXCL13 is already induced by IRI alone we used renal IRI models in mice with different ischemia times and a kidney transplantation model. We measured serum CXCL13 and characterized cell infiltrates by immunohistochemistry and performed single cell RNA sequencing. Allogenic and isogenic kidney transplantation (KTX) in mice was done to evaluate these findings in the transplant setting.

Results

Systemic CXCL13 levels increased within hours after surgery in a time dependent manner, both after induction of IRI and KTX. Levels of CXCL13 increased with duration of ischemia time and were higher in allogenic than isogenic transplantation with equal duration of ischemia. CXCR5, the receptor for CXCL13, is mainly expressed on B lymphocytes but also on a subset of T lymphocytes and macrophages. CXCR5 positive infiltrates were detected in IRI kidneys seven days after injury. In kidney allografts interstitial B cell infiltrates were observed as early as seven days and increased further towards three weeks after KTX.

Conclusion

The current findings indicate that IRI is a strong trigger of CXCL13 expression in the kidney and release into the circulation, which is followed by B lymphocyte infiltration into damaged tissue in ischemic and renal allografts.