Biology subjects

Libertucci, J.

Publications and source records attributed to Libertucci, J..

3 recordsLinked to original sources

bioRxiv2024

Detecting microbial engraftment after FMT: sorting signals from noise using placebo sequencing and culture-enriched metagenomics

Fecal microbiota transplantation (FMT) has shown efficacy for the treatment of ulcerative colitis but with variable response between patients and trials. The mechanisms underlying FMTs therapeutic effects remains poorly understood but is generally assumed to involve engraftment of donor microbiota into the recipients microbiome. Previous studies have reported microbial engraftment following FMT in various disease contexts but with inconsistent results between studies. Here we investigate engraftment in UC patients receiving FMT from a single donor applying amplicon-based profiling, shotgun metagenomics and culture-enriched metagenomics. Placebo samples were included to estimate engraftment noise, and a significant level of false-positive engraftment was observed which confounds the prediction of true engraftment. We show that analyzing engraftment across multiple patients from a single donor enhances the accuracy of detection. We identified a unique set of genes engrafted in responders to FMT which supports strain displacement as the primary mechanism of engraftment in our cohort.

microbiology↗

bioRxiv2019

Policy should change to improve invited speaker diversity and reflect trainee diversity

The biomedical sciences have a problem retaining white women and underrepresented minorities in academia. Despite increases in the representation of these groups in faculty candidate pools, they are still underrepresented at the faculty level, particularly at the Full Professor level. The lack of diverse individuals at the Full Professor level contributes to the attrition of women and under-represented minorities, as it confirms unconscious biases. The presence of unconscious biases contribute to feelings of not belonging by trainees and are amplified by visual representation of who is presented as the \"top scientist in their field\". Top scientists are not only defined by the attainment of Full Professorships, but also through invited seminar series. Invitations for faculty to present their research at other university departments is highly valued offer that provides an opportunity for collaborations and networking. However, if invited speakers do not represent the demographics of current trainees, these visual representations of successful scientists may contribute to decreased attitudes of self-identification as a scientist, ultimately resulting in trainees leaving the field or the academy. In this study, we compare invited-speaker demographics to the current trainee demographics in one microbiology and immunology department and find that trainees are not proportionally represented by speakers invited to the department. Our investigation prompted changes in policy for how invited speakers are selected in the future to invite a more diverse group of scientists. To facilitate this process, we developed a set of tips and a web-based resource that allows scientists, committees, and moderators to identify members of under-served groups. These resources can be easily adapted by other fields or sub-fields to promote inclusion and diversity at seminar series, conferences, and colloquia.

scientific communication and education↗

bioRxiv2019

Evaluation of Bacteria Detected in Both Urine and Open Wounds in Nursing Facility Residents

Nursing home residents are at a greater risk of developing pressure injuries that develop into an open wound. Open wounds can be colonized with bacteria from multiple sources. Emerging evidence suggests the specific composition of the open wound microbial community can result in delayed wound healing and increased infection risk. Understanding the factors that influence microbial colonization of open wounds, can lead to the prevention of infections. The relationship between bacteria found in urine and that of open wounds, is currently unknown. Recent studies have shown that nursing home residents can harbor a urinary microbiota independent of symptoms and frequently experience urinary incontinence. To determine if the colonization of open wounds mirrors urinary colonization, we conducted a pilot study with nursing home residents, comparing bacteria present in open pressure injuries below the umbilicus and urine. To identify microbial species that were present in both urine and open wound at one timepoint, standard bacteriologic culture techniques followed by MALDI-TOF was used as well as16S rRNA-encoding gene amplicon sequencing. In this study we found that some bacteria detected in urine were also detected in open wounds in one individual at one timepoint, using both culture dependent and independent techniques. Bacterial species that were more often detected at both sites included Enterococcus faecalis, Proteus mirabilis, Escherichia coli, and Providencia stuartii. This pilot study provides evidence that urinary colonization can mirror open wound colonization. Further studies are needed to investigate if parallel colonization of these anatomical sites affect infection outcomes.

microbiology↗