Deciphering bat influenza H18N11 infection dynamics in male Jamaican fruit bats on a single-cell level.

Jamaican fruit bats (Artibeus jamaicensis) naturally harbor a wide range of viruses of human relevance. These infections are typically mild in bats, suggesting unique features of their immune system. To better understand the immune response to viral infections in bats, we infected male Jamaican fruit bats with the bat-derived influenza A virus (IAV) H18N11. Using comparative single-cell RNA sequencing, we generated single-cell atlases of the Jamaican fruit bat intestine and mesentery. Gene expression profiling showed that H18N11 infection resulted in a moderate induction of interferon-stimulated genes and transcriptional activation of immune cells. H18N11 infection was predominant in various leukocytes, including macrophages, B cells, and NK/T cells. Confirming these findings, human leukocytes, particularly macrophages, were also susceptible to H18N11, highlighting the zoonotic potential of this bat-derived IAV. Our study provides insight into a natural virus-host relationship and thus serves as a fundamental resource for future in-depth characterization of bat immunology.

Bat-borne H9N2 influenza virus evades MxA restriction and exhibits efficient replication and transmission in ferrets.

Influenza A viruses (IAVs) of subtype H9N2 have reached an endemic stage in poultry farms in the Middle East and Asia. As a result, human infections with avian H9N2 viruses have been increasingly reported. In 2017, an H9N2 virus was isolated for the first time from Egyptian fruit bats (Rousettus aegyptiacus). Phylogenetic analyses revealed that bat H9N2 is descended from a common ancestor dating back centuries ago. However, the H9 and N2 sequences appear to be genetically similar to current avian IAVs, suggesting recent reassortment events. These observations raise the question of the zoonotic potential of the mammal-adapted bat H9N2. Here, we investigate the infection and transmission potential of bat H9N2 in vitro and in vivo, the ability to overcome the antiviral activity of the human MxA protein, and the presence of N2-specific cross-reactive antibodies in human sera. We show that bat H9N2 has high replication and transmission potential in ferrets, efficiently infects human lung explant cultures, and is able to evade antiviral inhibition by MxA in transgenic B6 mice. Together with its low antigenic similarity to the N2 of seasonal human strains, bat H9N2 fulfils key criteria for pre-pandemic IAVs.

Significant differences in femoral torsion values depending on the CT measurement technique.

INTRODUCTION: This study compared the feasibility of six different CT-based measurement techniques for establishing an indication for derotational osteotomy in the cases of patellar instability or femoral fracture. MATERIALS AND METHODS: CT scans of 52 single human cadaver femora were measured using six different torsion measurement techniques (described by Waidelich, Murphy, and Yoshioka on transverse images and Hernandez, Jarrett, and Yoshioka on oblique images). All measurements were performed by four observers twice to assess intraobserver and interobserver agreement. The intraclass correlation coefficient (ICC), ANOVA, and Bonferroni post hoc test were used for the statistical analysis. RESULTS: Significant differences (P < 0.001) between the values for femoral torsion were observed with all techniques except Yoshioka's techniques on transverse and oblique slices (P = 1.000) (transverse images: Waidelich 22.4° ± 6.8°, Murphy 17.5° ± 7.0°, Yoshioka 13.4° ± 6.9°; oblique images: Hernandez 11.4° ± 7.4°, Jarrett 14.9° ± 7.5°, Yoshioka oblique 13.4° ± 7.1°). Intraobserver and interobserver agreement showed a high level of reproducibility (ICC 0.877-0.986; mean 0.8°-2.9°) for all techniques, with the greatest difference being observed with Hernandez's technique (11.4°/10°). CONCLUSIONS: Femoral torsion values depend on the measurement technique. When derotational osteotomy is being considered, it is essential to use different threshold values depending on the measurement technique.