bioRxiv Science⌕ Search

bioRxiv · 10.1101/2022.06.30.498276

Development of zebrafish (Danio rerio) in vivo model for Borrelia burgdorferi infection

Abstract

Borrelia burgdorferi is the spirochetal bacterium that causes Lyme disease. Despite the fact that antimicrobial sensitivity of B. burgdorferi has been widely studied, there is still a need to develop an affordable, practical, high-throughput in vivo model which can be used to find effective antibiotic therapies, especially for the recently discovered persister and biofilm forms. Recent studies showed that Zebrafish (Danio rerio) could offer a novel, high-throughput, affordable model in antibiotic therapies for various infections agents can be studied. Therefore, in this study, we developed a straightforward, standardized infection procedure and tested it for zebrafish survival rate, morphological or behavioral changes post-infection as well as providing evidence that B. burgdorferi persists in zebrafish using polymerase chain reaction (PCR) and immunohistochemical (IHC) techniques. Morphological and physiological examination showed a significant size difference between control and infected zebrafish at 2 wpi, and infected zebrafish exhibited slower heart rates through 72 hpi. Furthermore, our results showed B. burgdorferi DNA can be detected and active replication of the B. burgdorferi 16S rRNA gene can be confirmed through 10 days post-infection via PCR and Reverse Transcription PCR respectively. Fluorescent microscopy and immunohistochemical staining revealed spirochetes present in the eyes, gills, heart, liver, tail, and hindbrain tissues though 72 hpi as well as the stomach and digestive tract at 2 weeks post-infection, respectively. These findings demonstrate that zebrafish could serve as a promising animal model to study the mechanism of B. burgdorferi infection as well as in vivo antibiotic sensitivity.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Misner, E., Zhang, M., Sapi, E.. 2022-06-30. Development of zebrafish (Danio rerio) in vivo model for Borrelia burgdorferi infection. https://doi.org/10.1101/2022.06.30.498276

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

KEEP EXPLORING

Related preprints

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↗

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↗

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↗