Ictogenesis of viral pneumonia: A comparison between SARS-CoV-2 and H1N1/H3N2.

Several studies reported acute symptomatic seizures as a possible neurological complication of COVID-19 pneumonia. Apart from metabolic imbalances, hypoxia, and fever, other ictogenic mechanisms are likely related to an immune-mediated damage. The same mechanisms are shared by other respiratory viruses. Since neurotropic properties of SARS-CoV-2 have been questioned, we investigated whether SARS-CoV-2 has a similar ictogenic potential to other respiratory non-neurotropic viruses. We conducted a retrospective study identifying 1141 patients with SARS-CoV-2 pneumonia and 146 patients with H1N1/H3N2 pneumonia. We found a similar prevalence of seizures in the two viral pneumonia (1.05% with SARS-CoV-2 vs 2.05% with influenza; p = 0.26). We detailed clinical, electroencephalographic, and neuroradiological features of each patient, together with the hypothesized pathogenesis of seizures. Previous epilepsy or pre-existing predisposing conditions (i.e., Alzheimer's disease, stroke, cerebral neoplasia) were found in one-third of patients that experienced seizures, while two-thirds of patients had seizures without known risk factors other than pneumonia in both groups. The prevalence of pre-existing predisposing conditions and disease severity indexes was similar in SARS-CoV-2 and H1N1/H3N2 pneumonia, thus excluding they could act as potential confounders. Considering all the patients with viral pneumonia together, previous epilepsy (p < 0.001) and the need for ventilatory support (p < 0.001), but not the presence of pre-existing predisposing conditions (p = 0.290), were associated with seizure risk. Our study showed that SARS-CoV-2 and influenza viruses share a similar ictogenic potential. In both these infections, seizures are rare but serious events, and can manifest without pre-existing predisposing conditions, in particular when pneumonia is severe, thus suggesting an interplay between disease severity and host response as a major mechanism of ictogenesis, rather than a virus-specific mechanism.

Rise of the BQ.1.1.37 SARS-CoV-2 Sublineage, Italy.

BQ.1.1 has dominated the Europe and Americas COVID-19 wave across the 2022-2023 winter, and further viral evolution is expected to escape the consolidating immune responses. We report here the emergence of the BQ.1.1.37 variant in Italy, peaking in January 2022 before suffering competition by XBB.1.*. We attempted to correlate the potential fitness of BQ.1.1.37 with a unique two-amino acid insertion within the Spike protein.

Efficacy of Convalescent Plasma to Treat Long-Standing COVID-19 in Patients with B-Cell Depletion.

The use of antivirals, corticosteroids, and IL-6 inhibitors has been recommended by the WHO to treat COVID-19. CP has also been considered for severe and critical cases. Clinical trials on CP have shown contradictory results, but an increasing number of patients, including immunocompromised ones, have shown benefits from this treatment. We reported two clinical cases of patients with prolonged COVID-19 infection and B-cell depletion who showed rapid clinical and virological recovery after the administration of CP. The first patient in this study was a 73-year-old female with a history of follicular non-Hodgkin lymphoma previously treated with bendamustine followed by maintenance therapy with rituximab. The second patient was a 68-year-old male with chronic obstructive pulmonary disease, bipolar disorder, alcoholic liver disease, and a history of mantellar non-Hodgkin lymphoma treated with rituximab and radiotherapy. After the administration of CP, both patients showed a resolution of symptoms, improvement of their clinical conditions, and a negative result of the nasopharyngeal swab test. The administration of CP might be effective in resolving symptoms and improving clinical and virological outcomes in patients with B-cell depletion and prolonged SARS-CoV2 infections.

First report of Wautersiella falsenii genomovar 2 isolated from the respiratory tract of an immunosuppressed man.

Wautersiella falsenii is a Gram-negative, non-motile rod, which grows aerobically on common isolation media and is the only acknowledged species among the genus Wautersiella. Two genomovars, namely 1 and 2, phenotypically indistinguishable but genotypically different, are described. To date, few case reports detailing the clinical disease associated with W. falsenii have been reported, all describing localized infection. To our knowledge, this study reports the first isolation of W. falsenii genomovar 2 from a respiratory sample of an immunosuppressed man. Our hypothesis is that the patient was harboring W. falsenii genomovar 2 and both the immunosuppression and the antimicrobial treatments provided a chance for this organism to emerge. The clinical significance of this result is yet to be evaluated. Although infection with W. falsenii remains rare, this bacterium should not be underestimated mainly because of its natural resistance to many available antimicrobials.

In vitro bactericidal activity of the N-terminal fragment of the frog peptide esculentin-1b (Esc 1-18) in combination with conventional antibiotics against Stenotrophomonas maltophilia.

In this study the bactericidal effect of the N-terminal fragment of the frog skin peptide esculentin-1b [Esc(1-18)] in combination with clinically used antimicrobial agents was evaluated against Stenotrophomonas maltophilia, either in standard conditions (phosphate buffer) or in the presence of human serum. A synergistic bactericidal effect was observed after a 24h incubation when combinations of Esc(1-18) and amikacin or colistin were used against clinical strains of S. maltophilia with or without resistance to these antibiotics, both in buffer and in the presence of serum. An indifferent effect was observed when the peptide was combined with levofloxacin or ceftazidime. A synergistic effect was also observed at earlier time points when the peptide was used in combination with colistin. Sequential exposure of bacterial cells to Esc(1-18) and amikacin or colistin, or vice versa, indicated that while Esc(1-18) and colistin cooperated in enhancing the bactericidal effect of their combination, when Esc(1-18) was combined with amikacin, the peptide had a major role in initiating the bactericidal effect, while amikacin was required for the subsequent effector phase. Altogether, the results obtained indicate that exposure of S. maltophilia to sub-bactericidal concentrations of Esc(1-18) increases its susceptibility to amikacin or colistin and may also render resistant strains susceptible to these antibiotics.