Mycobacterium abscessus are non-motile bacilli that cause soft-tissue and pulmonary infections, commonly in healthcare settings or patients with cystic fibrosis. Though it is considered an opportunistic pathogen, its many virulence factors signal its potential for evolution into a true pathogen. Upon infection, the bacilli are internalized by macrophages, forming granulomas to contain the infection. Macrophages can harbor bacilli during infection stages and induce drug resistance by expelling toxins through ABC transporters. Treatment is often challenging as M. abscessus is intrinsically resistant to many antibiotics. Current treatment uses a combination of two or more intravenous drugs and one or more oral antibiotics over several months. Treatment success is challenged by patient adherence and may also be impacted by drug efflux by macrophage ABC transporters. Transporters identify certain drugs as toxic to the body and try to flush them out of the cell. Since Mycobacteria infect macrophages, these channels pose a significant disadvantage to treatment since the cell will actively efflux the drug, preventing the drug's intracellular concentration from increasing to an effective level against the bacilli inside. Certain drugs are known to inhibit ABC transporters, and the addition of these inhibitors in treatment could increase bacteriocidal activity and reduce the development of drug tolerance. First, we will determine the drug's minimum inhibitory concentrations to each inhibitor to see if there is an intrinsic activity on M. abscessus. Next, we will use the Human THP-1 cell line infect with Mycobacterium abscessus and treat with known ABC transport inhibitors in concert with a current therapeutic drug, Clarithromycin. They will then be plated at various time points to determine the colony-forming units. If efflux by macrophage transporters reduces the efficacy of Clarithromycin, bacteriocidal activity will increase between the combination therapy and the clarithromycin-only treatment. These results may improve the current treatment regimens for M. abscessus.

Pregnant individuals infected with influenza A viruses (IAV) have higher risks of mortality, hospitalization, preterm birth, and stillbirth. The objective was to determine how the transcriptional program induced by IAV infection in the lung differs between pregnant and non-pregnant states. I hypothesized that a cluster of genes linked to aggravation of influenza disease would be upregulated in the pregnant lung early in IAV infection versus the non-pregnant lung. We used a non-human primate model [NHP; pregnant (N=10), non-pregnant (N=10); Macaca nemestrina, pigtail macaque] to investigate the transcriptional response in the lung of pregnant versus non-pregnant NHPs infected with the IAV CA/04/2009 (H1N1) strain. Maternal lung tissues were collected from the animals at necropsy 5 days after infection. mRNA-Seq was performed by first extracting mRNA from tissues, preparing mRNA libraries, and aligning raw sequencing data, using Spliced Transcripts Alignment to a Reference (STAR), to the macaque genome. I performed normalization of the raw gene count matrix using EdgeR in R Studio and alignment to the macaque reference genome. Next, I performed a single gene analysis using Limma-voom to determine differentially expressed genes (DEG). A total of 115 genes were significantly differentially expressed (>2-fold change, p<0.05) with 77 upregulated and 38 downregulated. Remarkably, genes linked to aggravation of influenza A viral disease, tissue injury, or acidification were upregulated in the infected pregnant versus non-pregnant lung 5 days after infection (MMP8, ATP12A, LGR4, NUP58, KBTBD6; log2fold change 1.28 - 2.8, all p<0.05). Next steps include gene set enrichment analysis and ingenuity pathway analysis to further investigate the gene networks linked to these upregulated genes. In summary, pregnancy was associated with upregulation of genes in the lungs 5 days after IAV infection that may predispose to greater tissue injury versus the non-pregnant lung.