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Morrison, H. G.

Publications and source records attributed to Morrison, H. G..

2 recordsLinked to original sources

Profiling of bacterial and fungal microbial communities in cystic fibrosis sputum using RNA

Here, we report an approach to detect diverse bacterial and fungal taxa in complex samples by direct analysis of community RNA in one step using NanoString probe sets. We designed rRNA-targeting probe sets to detect forty two bacterial and fungal genera or species common in cystic fibrosis (CF) sputum, and demonstrated taxon-specificity of these probes as well as a linear response over more than three logs of input RNA. Culture-based analyses correlated qualitatively with relative abundance data on bacterial and fungal taxa obtained by NanoString and the analysis of serial samples demonstrated the use of this method to simultaneously detect bacteria and fungi and to detect microbes at low abundance without an amplification step. The relative abundances of bacterial taxa detected by analysis of RNA correlated with the relative abundances of the same taxa as measured by sequencing of the V4V5 region of the 16S rRNA gene amplified from community DNA from the same sample. We propose that this method may complement other methods designed to understand dynamic microbial communities, may provide information on bacteria and fungi in the same sample with a single assay, and, with further development, may provide quick and easily-interpreted diagnostic information on diverse bacteria and fungi at the genus or species level.\n\nImportanceHere we demonstrate the use of an RNA-based analysis of specific taxa of interest, including bacteria and fungi, within microbial communities. This multiplex method may be useful as a means to identify samples with specific combinations of taxa and to gain information on how specific populations vary over time and space or in response to perturbation. A rapid means to measure bacterial and fungal populations may aid in the study of host response to changes in microbial communities.

microbiology

High-resolution tracking of microbial colonization in Fecal Microbiota Transplantation experiments via metagenome-assembled genomes

Fecal microbiota transplantation (FMT) is an effective treatment for recurrent Clostridium difficile infection and shows promise for treating other medical conditions associated with intestinal dysbioses. However, we lack a sufficient understanding of which microbial populations successfully colonize the recipient gut, and the widely used approaches to study the microbial ecology of FMT experiments fail to provide enough resolution to identify populations that are likely responsible for FMT-derived benefits. Here we used shotgun metagenomics to reconstruct 97 metagenome-assembled genomes (MAGs) from fecal samples of a single donor and followed their distribution in two FMT recipients to identify microbial populations with different colonization properties. Our analysis of the occurrence and distribution patterns post-FMT revealed that 22% of the MAGs transferred from the donor to both recipients and remained abundant in their guts for at least eight weeks. Most MAGs that successfully colonized the recipient gut belonged to the order Bacteroidales. The vast majority of those that lacked evidence of colonization belonged to the order Clostridiales and colonization success was negatively correlated with the number of genes related to sporulation. Although our dataset showed a link between taxonomy and the ability of a MAG to colonize the recipient gut, we also identified MAGs with different colonization properties that belong to the same taxon, highlighting the importance of genome-resolved approaches to explore the functional basis of colonization and to identify targets for cultivation, hypothesis generation, and testing in model systems for mechanistic insights.

microbiology