Substrate Specifity Profiling of the Aspergillus fumigatus Proteolytic Secretome Reveals Consensus Motifs with Predominance of Ile/Leu and Phe/Tyr

The filamentous fungus Aspergillus fumigatus (AF) can cause devastating infections in immunocompromised individuals. Early diagnosis improves patient outcomes but remains challenging because of the limitations of current methods. To augment the clinician's toolkit for rapid diagnosis of AF infections, we are investigating AF secreted proteases as novel diagnostic targets. The AF genome encodes up to 100 secreted proteases, but fewer than 15 of these enzymes have been characterized thus far. Given the large number of proteases in the genome, studies focused on individual enzymes may overlook potential diagnostic biomarkers.As an alternative, we employed a combinatorial library of internally quenched fluorogenic probes (IQFPs) to profile the global proteolytic secretome of an AF clinical isolate in vitro. Comparative protease activity profiling revealed 212 substrate sequences that were cleaved by AF secreted proteases but not by normal human serum. A central finding was that isoleucine, leucine, phenylalanine, and tyrosine predominated at each of the three variable positions of the library (44.1%, 59.1%, and 57.0%, respectively) among substrate sequences cleaved by AF secreted proteases. In contrast, fewer than 10% of the residues at each position of cleaved sequences were cationic or anionic. Consensus substrate motifs were cleaved by thermostable serine proteases that retained activity up to 50°C. Precise proteolytic cleavage sites were reliably determined by a simple, rapid mass spectrometry-based method, revealing predominantly non-prime side specificity. A comparison of the secreted protease activities of three AF clinical isolates revealed consistent protease substrate specificity fingerprints. However, secreted proteases of A. flavus, A. nidulans, and A. terreus strains exhibited striking differences in their proteolytic signatures.This report provides proof-of-principle for the use of protease substrate specificity profiling to define the proteolytic secretome of Aspergillus fumigatus. Expansion of this technique to protease secretion during infection could lead to development of novel approaches to fungal diagnosis

Experience of the use of Ketamine to manage opioid withdrawal in an addicted woman: a case report

International audienceBACKGROUND: Opioids are good painkillers, but many patients treated with opioids as painkillers developed a secondary addiction. These patients need to stop misusing opioids, but the mild-to-severe clinical symptoms associated with opioid withdrawal risk increasing their existing pain. In such cases, ketamine, which is used by anaesthetists and pain physicians to reduce opioid medication, may be an effective agent for managing opioid withdrawal.CASE PRESENTATION: We describe the case of a woman who developed a severe secondary addiction to opioids in the context of lombo-sciatic pain. She presented a severe opioid addiction, and her physicians refused to prescribe such high doses of opioid treatment (oxycontin® extended-release 120 mg daily, oxycodone 60 mg daily, and acetaminophen/codeine 300 mg/25 mg 6 times per day). To assist her with her opioid withdrawal which risked increasing her existing pain, she received 1 mg/kg ketamine oral solution, and two days after ketamine initiation her opioid treatment was gradually reduced. The patient dramatically reduced the dosage of opioid painkillers and ketamine was withdrawn without any withdrawal symptoms.CONCLUSION: Ketamine displays many interesting qualities for dealing with all symptoms relating to opioid withdrawal. Accordingly, it could be used instead of many psychotropic treatments, which interact with each other, to help with opioid withdrawal. However, the literature describes addiction to ketamine. All in all, although potentially addictive, ketamine could be a good candidate for the pharmacological management of opioid withdrawal