The pathology of respiratory syncytial virus (RSV) infection remains unclear. An unbalanced immune response to RSV infection can lead to immunopathology, causing airway damage and impaired exchange of oxygen and carbon dioxide between the air and the bloodstream. We aimed to evaluate the association of the expression of inflammatory and antiviral genes in peripheral blood with severe hypoxemia in children with RSV infection seen in the hospital emergency room. We conducted a cross-sectional study on 121 RSV-infected children seen in hospital emergency rooms between 2015 and 2023. Total RNA was extracted from whole blood samples, and gene expression (IL-6, TNFα, CXCL8, ISG15, IFIT1, RIGI, IFNβ, CCL5, and CXCL10) was quantified using quantitative RT-PCR. The outcome variable was having severe hypoxemia (SpO₂ ≤ 90%). The association analysis was performed using a volcano plot, adjusted logistic regression, and orthogonal partial least squares discriminant analysis (OPLS-DA). We found that 26 of 121 children had severe hypoxemia (SpO₂ ≤ 90%). CXCL8 was overexpressed [fold changes (FC) > 2; q-value < 0.05], and ISG15, IFIT1, RIGI, IFNβ, CCL5, and CXCL10 were underexpressed (FC <0.5; q-value <0.05) in children with severe hypoxemia. These associations were ratified using adjusted logistic regression. The OPLS-DA showed that the gene expressions of CXCL8, ISG15, IFIT1, RIGI, and CXCL10 had values of variable importance in projection (VIP) ≥1, being the most relevant features. In conclusion, an imbalance favoring inflammation over antiviral defense may contribute to the pathogenesis of severe hypoxemia in RSV-infected children. These findings provide valuable insights into the pathology of RSV infection.

Cancer patients often have weakened immune systems, resulting in a lower response to vaccines, especially those receiving immunosuppressive oncological treatment (OT). We aimed to assess the impact of OT on the humoral and T-cell response to the B.1 lineage and Omicron variant following COVID-19 vaccination in patients with solid and hematological neoplasms. We conducted a prospective study on cancer patients, stratified into OT and non-OT groups, who received a two-dose series of the COVID-19 mRNA vaccine and a booster six months later. The outcomes measured were the humoral (anti-SARS-CoV-2 S IgG titers and ACE2-S interaction inhibition capacity) and cellular (SARS-CoV-2 S-specific T-cell spots per million PBMCs) responses against the B.1 lineage and Omicron variant. These responses were evaluated four weeks after the second dose (n = 98) and eight weeks after the booster dose (n = 71). The humoral response after the second vaccine dose against the B.1 lineage and Omicron variant was significantly weaker in the OT group compared to the non-OT group (q-value<0.05). A booster dose of the mRNA-1273 vaccine significantly improved the humoral response in the OT group, making it comparable to the non-OT group. The mRNA-1273 vaccine, designed for the original Wuhan strain, elicited a weaker humoral response against the Omicron variant compared to the B.1 lineage, regardless of oncological treatment or vaccine dose. In contrast, T-cell responses against SARS-CoV-2, including the Omicron variant, were already present after the second vaccine dose and were not significantly affected by oncological treatments. Cancer patients, particularly those receiving immunosuppressive oncological treatments, should require booster doses and adapted COVID-19 vaccines for new SARS-CoV-2 variants like Omicron. Future studies should evaluate the durability of the immune response and the efficacy of individualized regimens.

Introduction: Targeting bacterial DNA damage responses such as the SOS response represents a promising strategy for enhancing the efficacy of existing antimicrobials. This study focuses on a recently discovered DNA damage response mechanism involving tricarboxylic acid cycle (TCA) fumarases and the adaptive response, crucial for Escherichia coli survival in the presence of genotoxic methyl methanesulfonate (MMS). We investigated whether this pathway contributes to protection against antibiotics, either separately or in combination with the SOS response.Methods: An isogenic collection of E. coli BW25113 mutants was used, including strains deficient in fumarases (ΔfumA, ΔfumB, ΔfumC) and the adaptive response (ΔalkA, ΔalkB, ΔaidB). Additional SOS response inactivation (ΔrecA) was conducted by P1 phage transduction. All mutants were subjected to antimicrobial susceptibility testing, growth curve analysis, survival and evolution assays. To validate the relevance of these findings, experiments were also performed in a quinolone-resistant E. coli ST131 clinical isolate.Results and discussion: Overall, no significant differences or only moderate increases in susceptibility were observed in the single mutants, with ΔfumC and ΔaidB mutants showing the highest susceptibility. To enhance this effect, these genes were then inactivated in combination with the SOS response by constructing ΔfumC/ΔrecA and ΔaidB/ΔrecA mutants. These combinations exhibited significant differences in susceptibility to various antimicrobials, particularly cephalosporins and quinolones, and especially in the ΔfumC/ΔrecA strain. To further assess these results, we constructed an E. coli ST131 ΔfumC/ΔrecA mutant, in which a similar trend was observed. Together, these findings suggest that co-targeting the SOS response together with fumarases or the adaptive response could enhance the effectiveness of antibiotics against E. coli, potentially leading to new therapeutic strategies.

Background: The current diagnostic strategy for hepatitis C virus (HCV) infection involves a two-step approach: antibody HCV screening followed by confirmatory nucleic acid testing. This study aimed to evaluate the diagnostic performance of the Abbott ARCHITECT HCV Ag assay in serum/plasma samples as a potential one-step alternative for diagnosing active HCV infection in people living with hepatitis B virus (PLWHB) through a systematic review and meta-analysis. Methods: A systematic review and meta-analysis were conducted following PRISMA-DTA guidelines. This protocol was registered on PROSPERO (CRD42023402093). A comprehensive search of electronic databases identified studies published up to 1 November 2024, comparing the ARCHITECT HCV Ag assay to an HCV-RNA reference standard. Sensitivity, specificity, and likelihood ratios were pooled using a random-effects model within the MIDAS module of Stata software. Study quality was assessed using QUADAS-2. Heterogeneity was evaluated using the Q statistic, quantified using the I², and further explored through meta-regression. Results: Ten studies (n = 494 participants) met inclusion criteria. The Abbott ARCHITECT HCV Ag assay demonstrated high sensitivity [91%, 95% confidence interval (CI): 76–97%] and specificity (99%, 95% CI: 99–100%). The positive likelihood ratio (PLR) was 81.20 (95% CI: 12.34–534.36), and the negative likelihood ratio (NLR) was 0.09 (95% CI: 0.03–0.27). The area under the summary receiver operating characteristic curve (AUC-SROC) was 99% (95% CI 98–100%). In regions with high HCV prevalence (≥ 10%), the test accurately confirmed active HCV infection in over 90% of cases. However, confirmatory testing remains necessary in low-prevalence settings (≤ 5%). The assay demonstrated an excellent ability to identify individuals without HCV infection, with a low false-negative rate (≤ 2%) regardless of HCV prevalence. Heterogeneity analysis revealed moderate to substantial variation in test performance (I² = 72.09% for sensitivity, 35.47% for PLR, and 78.33% for NLR). QUADAS-2 applicability concerns predicted heterogeneity, but differences were likely insignificant due to minimal variations and limited studies. Conclusions: The Abbott ARCHITECT HCV Ag assay exhibited promising accuracy in detecting active HCV infection among PLWHB. This test might help diagnose active HCV infection in high-prevalence scenarios (≥ 10%) but needs further confirmation in low-prevalence settings (≤ 5%). Graphical