Shiga Toxin-Mediated Hemolytic Uremic Syndrome: Time to Change the Diagnostic Paradigm?

Hemolytic uremic syndrome (HUS) is caused by enterohemorrhagic Escherichia coli (EHEC) which possess genes encoding Shiga toxin (stx), the major virulence factor, and adhesin intimin (eae). However, the frequency of stx-negative/eae-positive E. coli in stools of HUS patients and the clinical significance of such strains are unknown.Between 1996 and 2006, we sought stx-negative/eae-positive E. coli in stools of HUS patients using colony blot hybridization with the eae probe and compared the isolates to EHEC causing HUS. stx-negative/eae-positive E. coli were isolated as the only pathogens from stools of 43 (5.5%) of 787 HUS patients; additional 440 (55.9%) patients excreted EHEC. The majority (90.7%) of the stx-negative/eae-positive isolates belonged to serotypes O26:H11/NM (nonmotile), O103:H2/NM, O145:H28/NM, and O157:H7/NM, which were also the most frequent serotypes identified among EHEC. The stx-negative isolates shared non-stx virulence and fitness genes with EHEC of the corresponding serotypes and clustered with them into the same clonal complexes in multilocus sequence typing, demonstrating their close relatedness to EHEC.At the time of microbiological analysis, approximately 5% of HUS patients shed no longer the causative EHEC, but do excrete stx-negative derivatives of EHEC that lost stx during infection. In such patients, the EHEC etiology of HUS is missed using current methods detecting solely stx or Shiga toxin; this can hamper epidemiological investigations and lead to inappropriate clinical management. While maintaining the paradigm that HUS is triggered by Shiga toxin, our data demonstrate the necessity of considering genetic changes of the pathogen during infection to adapt appropriately diagnostic strategies

Separation and Characterization of NOM Intermediates Along AOP Oxidation

Removal of natural organic matter (NOM) in drinking water treatment systems has been a matter of thorough study in recent years. NOM affects organoleptic properties of water and causes membrane fouling; it may act as energy source for microorganisms in distribution systems and leads to the formation of undesired disinfection by-products through its interaction with chlorine. Currently the role played by advanced oxidation processes in the removal of NOM has gained great interest; understanding the composition and behaviour of NOM throughout such a kind of processes may allow to get significant insight in order to improve efficiency. In this chapter the main techniques useful for characterization are described, and their use to investigate the changes undergone by NOM throughout several AOPs has been reviewed

Multilevel Acute Spinal Epidural Hematoma In A Patient With Chronic Renal Failure - Case Report

A 47-year-old female with diabetic nephropathy presented with acute onset of severe back pain and progressive weakness in both lower extremities. Neuroimaging revealed a spinal epidural hematoma extending from the T-3 vertebra to the sacrum. Removal of all or every other lamina on levels with epidural hematoma and emergent evacuation of the hematoma were planned. T-9 and T-10 laminectomies were performed, but excessive bleeding during the operation prompted us to abandon the procedure. Plasma and desmopressin administration controlled the bleeding from the drain 8 hours after the operation. Follow-up neuroimaging one month later revealed total resolution of the hematoma with improved neurological status. Acute spinal epidural hematomas extending over more than 15 segments are extremely rare and the surgical treatment is still challenging. Coexisting hemorrhagic diathesis creates more problems. Conservative treatment may be the best option.WoSScopu

The optical properties of adenine cation in different oligonucleotides: a PCM/TD-DFT study

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