Document Type

Honors Thesis

Major

Microbiology

Advisor(s)

Sally Molloy

Committee Members

Edward Bernard, Mark Haggerty, Benjamin King, Jennifer Newell-Caito

Graduation Year

May 2021

Publication Date

Spring 5-2021

Abstract

Mycobacterium abscessus is a mycobacterial pathogen responsible for pulmonary and disseminated infections in susceptible individuals and often is resistant to all antibiotic therapies, with cure rates ranging from 25% to 58% (Degiacomi et al., 2019).Investigating the mechanisms of extensive resistance in M. abscessus lends opportunities to develop more effective treatments. Prophage, viral sequences integrated into bacterial genomes, contribute to virulence and fitness in many bacterial pathogens including Escherichia coli O157:H7 and Vibrio cholerae (Fortier & Sekulovic, 2013). Yet, prophage in pathogenic mycobacteria are not well understood or studied. Recent work has demonstrated that the Mycobacterium chelonae prophage, McProf can function in concert with a second prophage to increase the expression of the conserved mycobacterial transcriptional regulator whiB7, which confers increased antibiotic resistance in mycobacteria (Cushman et al.,Unpublished). To understand how prophage, like McProf, may influence resistance in M. abscessus, we bioinformatically identified and extracted eight novel prophage genomes with high sequence identity to McProf from M. abscessus sequences in the database PATRIC. The new prophages and McProf were assigned a novel M. abscessus (Mab) cluster, MabR. Strains carrying MabR prophage genomes were analyzed for cohabitating prophage sequences. Of the 25 strains, over 84% of them carried cohabitating prophages. There were 25 cohabiting prophages identified, with only six of those being unique. Three were clustered into MabD, and MabC, MabG, and MabA1 each received one prophage. One cohabiting prophage was identified in 16 of the 25 strains, all other cohabiting prophages were found either in one strain or two strains.

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