Inflammatory and cytotoxic mediators in COVID-19 patients and in ChAdOx1 nCoV-19 (AZD1222) vaccine recipients.

Immunological and cytotoxic mediators are induced in natural infection and are essential for the effectiveness of vaccination. Vaccination is useful to prevent the spread of SARS-CoV-2 and limit the morbidity/mortality of COVID-19. ChAdOx1 nCoV-19 is one of the most widespread vaccines in the world. We compared the detection of anti-S1 SARS-CoV2 IgG and the profile of inflammatory and cytotoxic responses of patients who developed different clinical outcomes of COVID-19 with individuals previously exposed or not to the virus received the first and booster doses of ChAdOx1 nCoV-19. Plasma from 35 patients with COVID-19 and 11 vaccinated were evaluated by multiplex assay. Here, no vaccinated subjects had serious adverse effects. Those vaccinated with a booster dose had higher anti-S1 IgG than mild/moderate and recovered patients. Critically ill and deceased patients had IgG levels like those immunized. By univariate analysis, IL-2, IL-17, and perforin do not differentiate between patients and vaccinated individuals. Granzyme A increased at dose 1, while patients had their levels reduced. High levels of granulysin, sFas, and IL-6 were detected in the deaths, but after vaccination, all were declined. The multivariate analysis supports the role of IL-6 and granulysin as associated and non-confounding variables related to the worst clinical outcome of COVID-19, but not sFas. Our data confirm the ability of the ChAdOx1 vaccine to produce specific antibody levels up to booster time. Furthermore, our data suggest that the vaccine can regulate both the hyper-production and the kinetics of the production of inflammatory and cytotoxic mediators involved in the cytokine storm, such as granulysin and IL-6.

Virulence and resistance properties of E. coli isolated from urine samples of hospitalized patients in Rio de Janeiro, Brazil - The role of mobile genetic elements.

Extraintestinal pathogenic E. coli (ExPEC) is the most frequent etiological agent of urinary tract infections (UTIs). Particular evolutionary successful lineages are associated with severe UTIs and higher incidences of multidrug resistance. Most of the resistance genes are acquired by horizontal transfer of plasmids and other mobile genetic elements (MGEs), and this process has been associated with the successful dissemination of particular lineages. Here, we identified the presence of MGEs and their role in virulence and resistance profiles of isolates obtained from the urine of hospitalized patients in Brazil. Isolates belonging to the successful evolutionary lineages of sequence type (ST) 131, ST405, and ST648 were found to be multidrug-resistant, while those belonging to ST69 and ST73 were often not. Among the ST131, ST405, and ST648 isolates with a resistant phenotype, a high number of mainly IncFII plasmids was identified. The plasmids contained resistance cassettes, and these were also found within phage-related sequences and the chromosome of the isolates. The resistance cassettes were found to harbor several resistance genes, including blaCTX-M-15. In addition, in ST131 isolates, diverse pathogenicity islands similar to those found in highly virulent ST73 isolates were detected. Also, a new genomic island associated with several virulence genes was identified in ST69 and ST131 isolates. In addition, several other MGEs present in the ST131 reference strain EC958 were identified in our isolates, most of them exclusively in ST131 isolates. In contrast, genomic islands present in this reference strain were only partially present or completely absent in our ST131 isolates. Of all isolates studied, ST73 and ST131 isolates had the most similar virulence profile. Overall, no clear association was found between the presence of specific MGEs and virulence profiles. Furthermore, the interplay between virulence and resistance by acquiring MGEs seemed to be lineage dependent. Although the acquisition of IncF plasmids, specific PAIs, GIs, and other MGEs seemed to be involved in the success of some lineages, it cannot explain the success of different lineages, also indicating other (host) factors are involved in this process. Nevertheless, the detection, identification, and surveillance of lineage-specific MGEs may be useful to monitor (new) emerging clones.

Different aspects of platelet evaluation in dengue: Measurement of circulating mediators, ability to interact with the virus, the degree of activation and quantification of intraplatelet protein content.

Platelets play a role in hemostasis, coagulation, angiogenesis, inflammation and immune response is one of the most affected cells in dengue. Here we describe some aspects of platelets by observing their specific circulating mediators, the ability to interact with the virus and morphological consequences of this interaction, activation markers and intraplatelet protein contents in dengue. We conducted this study using dengue-patients as well as healthy donors. Immunoenzymatic assay, flow cytometry, transmission electron microscopy and intraplatelet proteins expression assays were carried out. Briefly, we found an increase in sCD62L, NO or TBX2 ratio in platelet count, mostly in patients with the worse clinical outcome. After in vitro DENV infection or during natural infection, platelets underwent morphological alteration with increased expression of platelet activation markers, particularly in natural infections. Analysis of intraplatelet protein contents revealed different angiogenic and inflammatory profiles, maintaining or not extracellular matrix integrity between DF and DFWS patients. Thus, platelets are frequently affected by dengue, either by altering their own functionality, as "carrier" of the virus, or as an antiviral and mediator-secreting effector cell. Thus, strategies aimed at recovering platelet amounts in dengue seem to be essential for a better clinical outcome of the patients.