Integrated Pathophysiology of Pyelonephritis

Kidney involvement during the course of febrile urinary tract infection

Febrile urinary tract infections (fUTIs) are among the most common severe infections in the pediatric population, posing a significant risk to kidney health. The pathophysiology of fUTIs involves the direct bacterial invasion of kidney tissue, which triggers an inflammatory response. While this response is effective in eradicating the infection, it can also cause substantial kidney damage at multiple levels. In this review, we explore the various forms of kidney involvement in fUTIs, along with their clinical, radiological, and biochemical presentations. We also discuss the implications of these events for the long-term prognosis of kidney function. Understanding these manifestations can assist clinicians in making prompt diagnoses and initiating appropriate treatment to minimize complications such as sepsis, kidney scarring, and long-term kidney damage.

Predominantly multiple focal non-cystic renal lesions: an imaging approach

Multiple non-cystic renal lesions are occasionally discovered during imaging for various reasons and poses a diagnostic challenge to the practicing radiologist. These lesions may appear as a primary or dominant imaging finding or may be an additional abnormality in the setting of multiorgan involvement. Awareness of the imaging appearance of the various entities presenting as renal lesions integrated with associated extrarenal imaging findings along with clinical information is crucial for a proper diagnostic approach and patient work-up. This review summarizes the most relevant causes of infectious, inflammatory, vascular, and neoplastic disorders presenting as predominantly multiple focal non-cystic lesions.

Zidovudine in synergistic combination with nitrofurantoin or omadacycline: in vitro and in murine urinary tract or lung infection evaluation against multidrug-resistant Klebsiella pneumoniae

Limited treatment options and multidrug-resistant (MDR) Klebsiella pneumoniae present a significant therapeutic challenge, underscoring the need for novel approaches. Drug repurposing is a promising tool for augmenting the activity of many antibiotics. This study aimed to identify novel synergistic drug combinations against K. pneumoniae based on drug repurposing. We used the clinically isolated GN 172867 MDR strain of K. pneumoniae to determine the reversal resistance activity of zidovudine (AZT). The combined effects of AZT and various antibiotics, including nitrofurantoin (NIT) and omadacycline (OMC), were examined using the checkerboard method, growth curves, and crystal violet assays to assess biofilms. An in vitro combination activity testing was carried out in 12 isolates of K. pneumoniae. In vivo murine urinary tract and lung infection models were used to evaluate the therapeutic effects of AZT + NIT and AZT + OMC, respectively. The fractional inhibitory concentration index and growth curve demonstrated that AZT synergized with NIT or OMC against K. pneumoniae strains. In addition, AZT + NIT inhibited biofilm formation and cleared mature biofilms. In vivo, compared with untreated GN 172867-infected mice, AZT + NIT and AZT + OMC treatment decreased colony counts in multiple tissues (P < 0.05) and pathological scores in the bladder and kidneys (P < 0.05) and increased the survival rate by 60% (P < 0.05). This study evaluated the combination of AZT and antibiotics to treat drug-resistant K. pneumoniae infections and found novel drug combinations for the treatment of acute urinary tract infections. These findings suggest that AZT may exert significant anti-resistance activity.

The diagnosis and management of a patient with acute pyelonephritis

Lower urinary tract infections account for more than 224 000 hospital admissions each year and nearly all of these have the pathophysiological possibility to develop into pyelonephritis, known clinically as an upper urinary tract infection. Acute pyelonephritis is characterised by inflammation of the renal parenchyma caused by bacteriuria ascending from the bladder, up the ureters to the kidneys. Effective history taking, combined with refined physical examination skills, are the two most powerful tools to differentiate upper and lower urinary tract infections as well as assisting the practitioner to exclude other differential diagnoses. Utilisation of these skills by the practitioner, together with the recognised presenting symptom triad of flank pain, fever and nausea in this case study, enabled the diagnosis of acute pyelonephritis to be given.