Marinelli, L. J. | bioRxiv Science

bioRxiv2020

Putative Pseudolysogeny-Dependent Phage Gene Implicated in the Superinfection Resistance of Cutibacterium acnes

BackgroundBacteriophage therapy is a promising option to minimize the risk of treatment-associated antibiotic resistance in Cutibacterium acnes. A novel phage (Aquarius) was isolated and analyzed to explore characteristics of C. acnes phages that may confer lysis-evasion properties. Materials and MethodsPhage superinfection resistance assays were performed with a range of C. acnes phages, which were assayed for pseudolysogeny via phage release assays and episome PCR. Bioinformatics and qRT-PCR were used to identify candidate genes related to observed phenotypes. ResultsAssay findings indicated that infected C. acnes strains were broadly resistant to superinfection and were capable of forming stable pseudolysogens. A conserved Ltp family-like gene contained protein signatures which may be contributing to phage-mediated superinfection resistance in a pseudolysogeny-dependent manner. ConclusionsC. acnes bacteria are capable of harboring phage pseudolysogens, and this phenomenon may result in superinfection resistance, necessitating consideration in targeting optimization of C. acnes phage-based therapy.

microbiology↗

bioRxiv2017

A Novel Uropathogenic Escherichia Coli Genome (strain D3) and Comparative Analysis with Other Uropathogenic and Nonpathogenic Strains

BackgroundBacterial urinary tract infections are extremely prevalent, with half of women having at least one infection at some point in their lives. Most often the causative pathogen is the common gut microbe Escherichia coli. One such E. coli, strain D3, caused a bladder infection in a male adult, and was resistant to multiple antibiotics. We sequenced and assembled the genome of D3, and present it along with a comparative analysis against other pathogenic and nonpathogenic E. Coli strains.\n\nResultsBy comparing the predicted proteins of D3 with those from 5 uropathogenic and 7 nonpathogenic E. Coli strains, we generated a list of 38 genes present in most (4-5) pathogenic strains, but absent in all nonpathogenic strains. Among these were 9 proteins of the Pap fimbrial operon, which has previously been associated with cell adherence and the formation of biofilms. Lastly, we analyzed the list of predicted genes uniquely present in D3 compared to all other strains, and identified multiple transposable elements.\n\nConclusionsThe presence of fimbria in most pathogenic E. coli strains, and their absence in nonpathogenic ones, suggests that they play a role in pathogenicity, a notion supported by previous work. We also found that D3-specific genes are strongly enriched with transposases, recombinases, and integrase, suggesting that these mobile elements have been inserted or expanded in D3, relative to other strains in the study.

pathology↗