The Impact of COVID-19 on Breastfeeding Initiation and Duration in a Low-Income Population, Washington, DC.

Objective: To assess the impact of the coronavirus disease 2019 (COVID-19) pandemic on breastfeeding initiation (BFI) and duration among women enrolled in the Special Supplemental Nutrition Program for women, infants, and children (WIC) in Washington District of Columbia (DC). Materials and Methods: We used WIC program data from Washington DC to assess the pandemic's impact on BFI and duration among WIC recipients. t-Tests and unadjusted odds ratios compared breastfeeding outcomes before and during the pandemic. Multivariable logistic and linear regression models estimated the pandemic's impact on initiation and duration, respectively, while controlling for social determinants of health and other factors. Results: BFI was similar among women who gave birth before (61.4%) or during the pandemic (60.4%) (p = 0.359). However, the proportion of women who breastfed at 1 month decreased significantly from 56.1% (before pandemic) to 47.6% (during pandemic) (p < 0.0001). This pattern for duration continued at 3 and 6 months: 46.9% to 37.1% (p < 0.0001) at 3 months and 34.8% to 25.7% (p < 0.0001) at 6 months. On average, women who delivered during the pandemic breastfed 33.9 fewer days than those who delivered before (p < 0.0001). Conclusions: BFI among DC WIC recipients was similar for infants born before or during the pandemic, and determinants of initiation remained similar to previous reports (e.g., race/ethnicity, education). However, for women who initiated breastfeeding, average duration was significantly lower for infants born during the pandemic than before. Our findings suggest the importance of leveraging WIC and other breastfeeding supports to promote breastfeeding during pandemics and other emergencies.

Haemophilus ducreyi Infection Induces Oxidative Stress, Central Metabolic Changes, and a Mixed Pro- and Anti-inflammatory Environment in the Human Host.

Few studies have investigated host-bacterial interactions at sites of infection in humans using transcriptomics and metabolomics. Haemophilus ducreyi causes cutaneous ulcers in children and the genital ulcer disease chancroid in adults. We developed a human challenge model in which healthy adult volunteers are infected with H. ducreyi on the upper arm until they develop pustules. Here, we characterized host-pathogen interactions in pustules using transcriptomics and metabolomics and examined interactions between the host transcriptome and metabolome using integrated omics. In a previous pilot study, we determined the human and H. ducreyi transcriptomes and the metabolome of pustule and wounded sites of 4 volunteers (B. Griesenauer, T. M. Tran, K. R. Fortney, D. M. Janowicz, et al., mBio 10:e01193-19, 2019, https://doi.org/10.1128/mBio.01193-19). While we could form provisional transcriptional networks between the host and H. ducreyi, the study was underpowered to integrate the metabolome with the host transcriptome. To better define and integrate the transcriptomes and metabolome, we used samples from both the pilot study (n = 4) and new volunteers (n = 8) to identify 5,495 human differentially expressed genes (DEGs), 123 H. ducreyi DEGs, 205 differentially abundant positive ions, and 198 differentially abundant negative ions. We identified 42 positively correlated and 29 negatively correlated human-H. ducreyi transcriptome clusters. In addition, we defined human transcriptome-metabolome networks consisting of 9 total clusters, which highlighted changes in fatty acid metabolism and mitigation of oxidative damage. Taken together, the data suggest a mixed pro- and anti-inflammatory environment and rewired central metabolism in the host that provides a hostile, nutrient-limited environment for H. ducreyi. IMPORTANCE Interactions between the host and bacteria at sites of infection in humans are poorly understood. We inoculated human volunteers on the upper arm with the skin pathogen H. ducreyi or a buffer control and biopsied the resulting infected and sham-inoculated sites. We performed dual transcriptome sequencing (RNA-seq) and metabolic analysis on the biopsy samples. Network analyses between the host and bacterial transcriptomes and the host transcriptome-metabolome network were used to identify molecules that may be important for the virulence of H. ducreyi in the human host. Our results suggest that the pustule is highly oxidative, contains both pro- and anti-inflammatory components, and causes metabolic shifts in the host, to which H. ducreyi adapts to survive. To our knowledge, this is the first study to integrate transcriptomic and metabolomic responses to a single bacterial pathogen in the human host.

A Quantitative Arabidopsis IRE1a Ribonuclease-Dependent in vitro mRNA Cleavage Assay for Functional Studies of Substrate Splicing and Decay Activities.

The unfolded protein response (UPR) is an adaptive eukaryotic reaction that controls the protein folding capacities of the endoplasmic reticulum (ER). The most ancient and well-conserved component of the UPR is Inositol-Requiring Enzyme 1 (IRE1). Arabidopsis IRE1a (AtIRE1) is a transmembrane sensor of ER stress equipped with dual protein kinase and ribonuclease (RNase) activities, encoded by its C-terminal domain. In response to both physiological stresses and pathological perturbations, AtIRE1a directly cleaves bZIP60 (basic leucine zipper 60) mRNA. Here, we developed a quantitative in vitro cleavage assay that combines recombinant AtIRE1a protein that is expressed in Nicotiana benthamiana and total RNA isolated from Arabidopsis leaves. Wild-type AtIRE1a as well as its variants containing point mutations in the kinase or RNase domains that modify its cleavage activity were employed to demonstrate their contributions to cleavage activity levels. We show that, when exposed to total RNA in vitro, the AtIRE1a protein cleaves bZIP60 mRNA. Depletion of the bZIP60 transcript in the reaction mixture can be precisely quantified by a qRT-PCR-mediated assay. This method facilitates the functional studies of novel plant IRE1 variants by allowing to quickly and precisely assess the effects of protein mutations on the substrate mRNA cleavage activity before advancing to more laborious, stable transgenic approaches in planta. Moreover, this method is readily adaptable to other plant IRE1 paralogs and orthologs, and can also be employed to test additional novel mRNA substrates of plant IRE1, such as transcripts undergoing degradation through the process of regulated IRE1-dependent decay (RIDD). Finally, this method can also be modified and expanded to functional testing of IRE1 interactors and inhibitors, as well as for studies on the molecular evolution of IRE1 and its substrates, providing additional insights into the mechanistic underpinnings of IRE1-mediated ER stress homeostasis in plant tissues.