Four of the nine sigmodontine tribes have species that serve as reservoirs of rodent-borne hantaviruses (RBO-HV), few have been studied in any depth. Several viruses have been associated with human cases of hantavirus pulmonary syndrome often through peridomestic exposure. Jabora (JABV) and Juquitiba (JUQV), harbored by Akodon montensis and Oligoryzomys nigripes, respectively, are endemic and sympatric in the Reserva Natural de Bosque Mbaracayú (RNBM), Paraguay, a protected area of the Interior Atlantic Forest. Rodent communities were surveyed along a 30 km stretch of the RNBM in eight vegetation classifications (Low, High, Bamboo, Riparian and Liana Forests, Bamboo Understory, Cerrado, and Meadow/Grasslands). We collected 417 rodents from which 11 species were identified; Akodon montensis was the predominant species (72%; 95%CI: 64.7%-76.3%), followed by Hylaeamys megacephalus (15% (11.2%-18.2%)) and Oligoryzomys nigripes (9% (6.6%-12.4%)). We examined the statistical associations among habitat (vegetation class) type, rodent species diversity, population structure (age, sex, and weight), and prevalence of RBO-HV antibody and/or viral RNA (Ab/RNA) or characteristic Leishmania tail lesions. Ab/RNA positive rodents were not observed in Cerrado and Low Forest. A. montensis had an overall Ab/RNA prevalence of 7.7% (4.9%-11.3%) and O. nigripes had an overall prevalence of 8.6% (1.8%-23.1%). For A. montensis, the odds of being Ab/RNA positive in High Forest was 3.73 times of the other habitats combined. There was no significant difference among age classes in the proportion of Ab/RNA positive rodents overall (p = 0.66), however, all 11 RNA-positive individuals were adult. Sex and habitat had independent prognostic value for hantaviral Ab/RNA in the study population; age, presence of tail scar/lesion (19% of the rodents) and weight did not. Adjusting for habitat, female rodents had less risk of becoming infected. Importantly, these data suggest habitat preferences of two sympatric rodent reservoirs for two endemic hantaviruses and the importance of including habitat in models of species diversity and habitat fragmentation.

Understanding the ecology of rodent-borne hantaviruses is critical to assessing the risk of spillover to humans. Longitudinal surveys have suggested that hantaviral prevalence in a given host population is tightly linked to rodent ecology and correlates with changes in the species composition of a rodent community over time and/or habitat composition. We tested two hypotheses to identify whether resource addition and/or habitat composition may affect hantavirus prevalence among two sympatric reservoir hosts in a neotropical forest: (i) increased food resources will alter the rodent community and thus hantaviral prevalence; and (ii) host abundance and viral seroprevalence will be associated with habitat composition. We established a baseline of rodent–virus prevalence in three grid pairs of distinct habitat compositions and subjected one grid of each pair to resource augmentation. Increased rodent species diversity was observed on grids where food was added versus untreated control grids during the first post-treatment sampling session. Resource augmentation changed species community composition, yet it did not affect the prevalence of hantavirus in the host population over time, nor was there evidence of a dilution effect. Secondly, we show that the prevalence of the virus in the respective reservoir hosts was associated with habitat composition at two spatial levels, independent of resource addition, supporting previous findings that habitat composition is a primary driver of the prevalence of hantaviruses in the neotropics.

The cytoplasmic human Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3 (APOBEC3 or A3) cytidine deaminases G and F (A3G and A3F) can block the spread of human immunodeficiency virus (HIV). HIV counteracts this cell-intrinsic defense through a viral protein called viral infectivity factor (Vif). Vif causes proteasomal degradation of A3G and A3F proteins (A3G/F) in HIV-producing cells to ensure infectivity of virions subsequently released from these cells. Here, we optimized a lead compound reported previously to boost cellular levels of A3G. The modified analogs designed, synthesized, and evaluated here inhibit cell-mediated post-translational degradation of A3G/F, whether Vif is present or not. This increases A3G/F incorporation into Vif-positive virions to decrease viral infectivity. The compounds and processes described here can facilitate the development of new anti-HIV therapeutics whose host-targeted effect may not be evaded by resistance-conferring mutations in HIV Vif.

N ⁶ -methyladenosine (m ⁶ A) is the most prevalent internal modification of cellular and viral RNA and is critical to the regulation of its localization, stability, and translation. Previous studies on the role of m ⁶ A during HIV-1 replication have produced conflicting results. Since m ⁶ A function can vary dramatically by cell type and state, here we aimed to clarify the role of the m ⁶ A machinery during HIV-1 replication in primary CD4+ T cells. Using CRISPR-Cas9 we targeted 46 cellular genes implicated in m ⁶ A or 5-methylcytosine (m ⁵ C) regulation and measured subsequent HIV-1 replication in primary CD4+ T cells. Only knockout of the m ⁶ A writer complex auxiliary proteins VIRMA and WTAP, and the m ⁶ A reader YTHDF2 were validated as significantly decreasing HIV-1 replication. In contrast, knockout of METTL3 or METTL14, which form the catalytic core of the writer complex, resulted in only marginal changes in HIV-1 infection, despite significant decreases in total cellular m ⁶ A levels. Chemical inhibition of METTL3 led to a dose-dependent decrease in HIV-1 infection, coupled with an increase in protein levels of METTL3 and other writer complex members. Expression of writer proteins was also co-dependent, revealing complex regulatory feedback mechanisms. Overall, these results clarify the role of epitranscriptomic machinery during HIV-1 replication in primary CD4+ T cells and suggest regulation by auxiliary members of the m ⁶ A writer complex is more influential than the function of the catalytic core itself on HIV-1 infection in primary CD4+ T cells. IMPORTANCE: m ⁶ A is the most common chemical modification on cellular and viral RNA and regulates its stability, localization, and translation. m ⁶ A modification and its regulation varies dramatically between cell types and cell states. In this study, we investigated the role of m ⁶ A factors during HIV-1 infection of physiologically relevant primary CD4+ T cells. Using CRISPR-Cas9 to knockout 46 cellular genes implicated in RNA modification, we found only the m ⁶ A writer complex auxiliary members WTAP and VIRMA, and the reader YTHDF2, significantly affected HIV-1 replication in these cells. In contrast, knockout of METTL3 or METTL14, which form the catalytic core of the writer complex, resulted in marginal changes in HIV-1 infection, despite larger reductions in total cellular m ⁶ A levels. Our findings suggest regulation by auxiliary members of the m ⁶ A writer complex is more influential than the function of the catalytic core itself on HIV-1 infection in primary CD4+ T cells.

Control of carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa spread in healthcare settings begins with timely and accurate laboratory testing practices. Survey results show most Veterans Affairs facilities are performing recommended tests to identify these organisms. Most facilities report sufficient resources to perform testing, though medium-complexity facilities report some perceived barriers.