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Mostowy, R.

Publications and source records attributed to Mostowy, R..

3 recordsLinked to original sources

DepoCatalog: Mapping the Diversity of 105 Recombinant Klebsiella Phage Depolymerases Across Sequence, Structure, and Substrate Specificity

A validated catalog of 105 recombinant depolymerases from Klebsiella phages covers 58 KL-types. 46 novel enzymes from prophages, jumbo phages, and common phages are linked to any known enzymatic activity against 14 classical serotypes and 12 genome-defined KL-types. Using activity-based profiling, structure prediction, and domain dissection, we developed a function-guided classification and a five-class structural catalog. This framework reveals highly specific enzymes active against up to three capsule types. K47 CPS was degraded by three diverse protein groups. Structurally similar depolymerases degrading particular CPS were found in distinct phage taxa, with highly conserved enzymes in Drulisvirus specific to K1-, K2-types. The exclusive depolymerases were found in siphoviruses targeting K2 and K62 serotypes. A case study of five structurally similar enzymes degrading KL22/KL37/KL111 and KL25/KL119 capsules suggested specificity switching via amino acid changes or C-domain modification. Klebsiella phage depolymerases catalog sheds light on their diversity, evolution, and potential application.

microbiology↗

vCOMBAT: a Novel Tool to Create and Visualize a COmputational Model of Bacterial Antibiotic Target-binding

MotivationAs antibiotic resistance creates a significant global health threat, we need not only to accelerate the development of novel antibiotics but also to develop better treatment strategies using existing drugs to improve their efficacy and prevent the selection of further resistance. We require new tools to rationally design dosing regimens to from data collected in early phases of antibiotic and dosing development. Mathematical models such as mechanistic pharmacodynamic drug-target binding explain mechanistic details of how the given drug concentration affects its targeted bacteria. However, there are no available tools in the literature that allows non-quantitative scientists to develop computational models to simulate antibiotic-target binding and its effects on bacteria. ResultsIn this work, we have devised an extension of a mechanistic binding-kinetic model to incorporate clinical drug concentration data. Based on the extended model, we develop a novel and interactive web-based tool that allows non-quantitative scientists to create and visualize their own computational models of bacterial antibiotic target-binding based on their considered drugs and bacteria. We also demonstrate how Rifampicin affects bacterial populations of Tuberculosis (TB) bacteria using our vCOMBAT tool. AvailabilityvCOMBAT online tool is publicly available at https://combat-bacteria.org/.

bioinformatics↗

Frequent recombination of pneumococcal capsule highlights future risks of emergence of novel serotypes.

Capsular diversity of Streptococcus pneumoniae constitutes a major obstacle in eliminating the pneumococcal disease. Such diversity is genetically encoded by almost 100 variants of the capsule polysaccharide locus (cps). However, the evolutionary dynamics of the capsule - the target of the currently used vaccines - remains not fully understood. Here, using genetic data from 4,469 bacterial isolates, we found cps to be an evolutionary hotspot with elevated substitution and recombination rates. These rates were a consequence of altered selection at this locus, supporting the hypothesis that the capsule has an increased potential to generate novel diversity compared to the rest of the genome. Analysis of twelve serogroups revealed their complex evolutionary history, which was principally driven by recombination with other serogroups and other streptococci. We observed significant variation in recombination rates between different serogroups. This variation could only be partially explained by the lineage-specific recombination rate, the remaining factors being likely driven by serogroup-specific ecology and epidemiology. Finally, we discovered two previously unobserved mosaic serotypes in the densely sampled collection from Mae La, Thailand, here termed 10X and 21X. Our results thus emphasise the strong adaptive potential of the bacterium by its ability to generate novel serotypes by recombination.

evolutionary biology↗