Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2022.10.27.514154

Acquisition of a large virulence plasmid (pINV) promoted temperature-dependent virulence and global dispersal of O96:H19 enteroinvasive Escherichia coli

Miles, S. L.·Torraca, V.·Dyson, Z. A.·Lopez-Jimenez, A. T.·Foster-Nyarko, E.·Jenkins, C.·Holt, K.·Mostowy, S.
View original source ↗Export metadata ↓

Abstract

Enteroinvasive Escherichia coli (EIEC) and Shigella are closely related agents of bacillary dysentery. It is widely viewed that EIEC and Shigella species evolved from E. coli via independent acquisitions of a large virulence plasmid (pINV) encoding a type three secretion system (T3SS). Sequence Type (ST)99 O96:H19 E. coli is an emergent clone of EIEC responsible for recent outbreaks in Europe and South America. Here, we reconstruct the evolutionary history of ST99 E. coli using BactDating, revealing distinct phylogenomic clusters of pINV-positive and -negative isolates. To study the impact of pINV acquisition on the virulence of this clone, we developed an EIEC-zebrafish infection model showing that virulence of ST99 EIEC is thermoregulated. Strikingly, zebrafish infection using the oldest available pINV-negative isolate reveals a separate, temperature-independent mechanism of virulence, indicating that ST99 non-EIEC strains were virulent before pINV acquisition. Taken together, these results suggest that an already pathogenic E. coli acquired pINV and that virulence of ST99 isolates became thermoregulated once pINV was acquired. ImportanceEnteroinvasive Escherichia coli (EIEC) and Shigella are etiological agents of bacillary dysentery. Sequence Type (ST)99 is an emergent clone of EIEC hypothesised to cause human disease by the recent acquisition of pINV, a large plasmid encoding a type three secretion system (T3SS) that confers the ability to invade human cells. Here, using phylogenomic reconstruction and zebrafish larvae infection, we show that the virulence of ST99 EIEC isolates is highly dependent on temperature, while pINV-negative isolates encode a separate temperature-independent mechanism of virulence. These results highlight that ST99 non-EIEC isolates may have been virulent before pINV acquisition and highlight an important role for pINV acquisition in the emergence of ST99 EIEC in humans, allowing wider dissemination across Europe and South America.

Explore related subjects

microbiologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Miles, S. L., Torraca, V., Dyson, Z. A., Lopez-Jimenez, A. T., Foster-Nyarko, E., Jenkins, C., Holt, K., Mostowy, S.. 2022-10-28. Acquisition of a large virulence plasmid (pINV) promoted temperature-dependent virulence and global dispersal of O96:H19 enteroinvasive Escherichia coli. https://doi.org/10.1101/2022.10.27.514154

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

A population-scale landscape of the subgingival microbiome reveals divergent routes to periodontal dysbiosis

Periodontitis is an archetypical mucosal inflammatory disease in which microbiome dysbiosis at the tooth-epithelial interface interacts with host genetic and behavioral risk factors to drive immune-mediated tissue destruction. Although subgingival microbiome compositional shifts are thought to parallel disease severity, microbiome variation at the population-level and its relationship to periodontal clinical phenotypes and disease-modifying factors remain poorly defined. Here, we use unsupervised manifold learning to map the compositional landscape of the subgingival microbiome in 1,355 adults spanning periodontal health to severe periodontitis. We identified eight latent microbiome states organized along a branching continuum from eubiosis to dysbiosis. An intermediate microbial configuration marked ecological destabilization and bifurcation into two distinct periodontitis-associated dysbiotic trajectories, distinguished by links to gingival inflammation and smoking. Although the microbiome trajectories broadly tracked periodontal destruction, a minority of individuals showed discordant microbiome-clinical phenotypes, with some individuals with periodontitis retaining otherwise eubiotic microbiomes enriched for low-abundance pathobionts, while some cases of health or mild disease had highly dysbiotic communities, suggesting distinct host susceptibility. Together, these findings define a population-scale ecological landscape of the subgingival microbiome, reveal divergent trajectories to periodontal dysbiosis, and highlight heterogeneity in the relationship between microbial community structure and clinical disease expression.

microbiology↗
bioRxiv2026

Beta-lactam enhancement against methicillin-resistant Staphylococcus aureus by cell wall blockade is autolysis-dependent: a butyrolactone derivative as case in point

Methicillin-resistant Staphylococcus aureus (MRSA) is non-susceptible to beta-lactams. Blockade of cell wall biosynthesis is a potential target for beta-lactam enhancement but requires further investigation. A butyrolactone derivative enhanced beta-lactams against MRSA strains by reducing the availability of D-Ala-D-Ala. Unlike D-cycloserine, it did not inhibit D-Ala-D-Ala ligase (Ddl). Nor did it show an additive or synergistic effect when combined with cycloserine, indicating a unique mechanism for blocking cell wall precursor production that does not involve the traditional Lipid II pathway. Notably, beta-lactam potentiation by our chemical or D-cycloserine was highly dependent on the intrinsic autolytic ability of the tested MRSA strains. Strains that resisted lysis upon Triton X-100 exposure showed a minimal increase in beta-lactam susceptibility, whereas highly autolytic strains showed significant changes in their beta-lactam MICs. We have thus identified autolytic ability as the Achilles Heel in the strategy of targeting cell wall biosynthesis for beta-lactam potentiation.

microbiology↗
bioRxiv2026

Rapid and largely reversible shifts in the canine fecal metabolome during dietary change

Diet can rapidly change the fecal metabolome, but less is known about recovery after the original diet is restored. We used untargeted UPLC-MS metabolomics to analyze 72 fecal samples from nine Pumi dogs during an owner-managed switch from dry food to raw food and back to dry food. Diet phase accounted for a large proportion of variation in both ionization modes. More than 13,000 LC-MS features changed at the first sampling point after the switch to raw food, with a similarly large response after return to dry food. Among features significant in both comparisons, more than 99% changed in opposite directions. At the final sampling point, no positive-mode (ESI+) features and only 13 negative-mode (ESI-) features differed from the second dry-food baseline under the same threshold. BARF-associated patterns persisted in analyses excluding individual dogs and in pedigree-adjusted candidate models, although individual feature effects depended on normalization. Putative metabolites from several biochemical classes differed in their response and recovery. The fecal metabolome therefore changed rapidly and returned largely toward baseline, with differences among dogs.

microbiology↗