Staphylococcus aureus subcapsular splenic abscess and associated empyema in the setting of tocilizumab therapy: A case report.

We report a case of Staphylococcus aureus subcapsular splenic abscess and associated empyema after recent commencement of tocilizumab, masquerading as musculoskeletal pain. This highlights the importance of considering unusual underlying infections in patients on tocilizumab.

DRESS syndrome with multiorgan involvement and HHV-6 reactivation in the absence of a drug trigger.

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe drug reaction where patients present with fever, morbilliform rash and multiorgan manifestations, which may include acute renal failure, acute respiratory distress syndrome and eosinophilic myocarditis. We present a case of a 60-year-old woman with acute heart failure, DRESS syndrome features and human herpesvirus 6 reactivation in the absence of a drug trigger. She was diagnosed with eosinophilic myocarditis and successfully treated with corticosteroid therapy.

Cutaneous leukocytoclastic vasculitis associated with verapamil and atorvastatin: A case report.

We report a case of biopsy-proven cutaneous leukocytoclastic vasculitis developing 10 days after starting verapamil and atorvastatin in a patient with long-standing Sjogren's syndrome. This highlights the need to monitor for this rare adverse effect.

A G358S mutation in the Plasmodium falciparum Na+ pump PfATP4 confers clinically-relevant resistance to cipargamin.

Diverse compounds target the Plasmodium falciparum Na+ pump PfATP4, with cipargamin and (+)-SJ733 the most clinically-advanced. In a recent clinical trial for cipargamin, recrudescent parasites emerged, with most having a G358S mutation in PfATP4. Here, we show that PfATP4G358S parasites can withstand micromolar concentrations of cipargamin and (+)-SJ733, while remaining susceptible to antimalarials that do not target PfATP4. The G358S mutation in PfATP4, and the equivalent mutation in Toxoplasma gondii ATP4, decrease the sensitivity of ATP4 to inhibition by cipargamin and (+)-SJ733, thereby protecting parasites from disruption of Na+ regulation. The G358S mutation reduces the affinity of PfATP4 for Na+ and is associated with an increase in the parasite's resting cytosolic [Na+]. However, no defect in parasite growth or transmissibility is observed. Our findings suggest that PfATP4 inhibitors in clinical development should be tested against PfATP4G358S parasites, and that their combination with unrelated antimalarials may mitigate against resistance development.

A key cytosolic iron-sulfur cluster synthesis protein localizes to the mitochondrion of Toxoplasma gondii.

Iron-sulfur (Fe-S) clusters are prosthetic groups on proteins that function in a range of enzymatic and electron transfer reactions. Fe-S cluster synthesis is essential for the survival of all eukaryotes. Independent Fe-S cluster biosynthesis pathways occur in the mitochondrion, plastid, and cytosolic compartments of eukaryotic cells. Little is known about the cytosolic Fe-S cluster biosynthesis in apicomplexan parasites, the causative agents of diseases such as malaria and toxoplasmosis. NBP35 serves as a key scaffold protein on which cytosolic Fe-S clusters assemble, and has a cytosolic localization in most eukaryotes studied thus far. Unexpectedly, we found that the NBP35 homolog of the apicomplexan Toxoplasma gondii (TgNBP35) localizes to the outer mitochondrial membrane, with mitochondrial targeting mediated by an N-terminal transmembrane domain. We demonstrate that TgNBP35 is critical for parasite proliferation, but that, despite its mitochondrial localization, it is not required for Fe-S cluster synthesis in the mitochondrion. Instead, we establish that TgNBP35 is important for the biogenesis of cytosolic Fe-S proteins. Our data are consistent with TgNBP35 playing a central and specific role in cytosolic Fe-S cluster biosynthesis, and imply that the assembly of cytosolic Fe-S clusters occurs on the cytosolic face of the outer mitochondrial membrane in these parasites.