Biology subjects

DePaolo, R. W.

Publications and source records attributed to DePaolo, R. W..

3 recordsLinked to original sources

bioRxiv2021

Polyunsaturated fatty acid arachidonic acid increases the virulence of gut pathogen, Yersinia enterocolitica

Food-borne illnesses are a major health concern worldwide. While 1 in 6 individuals are infected in the United States yearly, there is little research into which dietary factors can alter the risk of infection. Despite evidence suggesting a correlation between obesity and enteric infection, the few reported studies focus on the role of dietary factors and the impact on host tissues and susceptibility. The direct impact of dietary constituents on the virulence of a pathogen has largely been ignored. One component of the Western diet that has been correlated with increasing inflammatory diseases is increased consumption of omega-6 polyunsaturated fatty acids such as arachidonic acid. Here, we show that arachidonic acid directly alters the pathogenicity of the food-borne pathogen Yersinia enterocolitica. Using in vitro cellular adherence assays, proteomic peptide mass fingerprint profiles and in vivo mouse models, we show that arachidonic acid can alter the pathogenesis of Y. enterocolitica by increasing proliferation and intracellular invasion. These findings have major implications in more than food safety, potentially revealing how current dietary habits may increase the virulence of food-borne pathogens.

microbiology↗

bioRxiv2020

Proteomic changes in bacteria caused by exposure to environmental conditions can be detected by Matrix-Assisted Laser Desorption/Ionization - Time of Flight (MALDI-ToF) Mass Spectrometry

In the past decade, matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectrometry (MS) has become a timely and cost-effective alternative to bacterial identification. The MALDI-ToF MS technique analyzes the total protein of culturable microorganisms at the species level and produces a mass spectra based on peptides which is compared to a database of identified profiles. Consequently, unique signatures of each microorganism are produced allowing identification at the species and, more importantly, strain level. Our present study proposes that the MALDI-ToF MS can be further used to screen functional and metabolic differences. While other studies applied the MALDI-ToF technique to identify subgroups within species, we investigated how various environmental factors could alter the unique bacterial signatures. We found that genetic and phenotypic differences between microorganisms belonging to the same species can be reflected in peptide-mass fingerprints generated by MALDI-ToF MS. These results suggest that MALDI-ToF MS can screen intra-species phenotypic differences of several microorganisms.

microbiology↗

bioRxiv2019

Microbial single-cell RNA sequencing by split-pool barcoding

Single-cell RNA-sequencing (scRNA-seq) has become an essential tool for characterizing multi-celled eukaryotic systems but current methods are not compatible with bacteria. Here, we introduce microSPLiT, a low cost and high-throughput scRNA-seq method that works for gram-negative and gram-positive bacteria and can resolve transcriptional states that remain hidden at a population level. We applied microSPLiT to >25,000 Bacillus subtilis cells sampled from different growth stages, creating a detailed atlas of changes in metabolism and lifestyle. We not only retrieve detailed gene expression profiles associated with known but rare states such as competence and PBSX prophage induction, but also identify novel and unexpected gene expression states including heterogeneous activation of a niche metabolic pathway in a subpopulation of cells. microSPLiT empowers high-throughput analysis of gene expression in complex bacterial communities.

bioengineering↗