Background: USA300 is a uniquely successful methicillin-resistant Staphylococcus aureus (MRSA) clone that has been associated with Panton-Valentine leukocidin (PVL) production and severe infections. However, conflicting experimental and epidemiological data exist regarding the virulence of USA300 relative to other MRSA clones. We aimed to address this issue using Drosophila melanogaster as a model host to study strain and PVL-dependent variations in virulence among MRSA clinical isolates.
Results: We studied the relative virulence of 39 MRSA isolates: 17 (43%) were PFGE type USA300. Lethal MRSA infection was reproducibly induced both in wild-type (WT) and Toll-deficient D. melanogaster. USA300 strains had significantly lower lethality than non-USA300 strains in a WT background but not in Toll-deficient flies. PFGE type (USA300 versus non-USA300) and PVL status did not affect the response to treatment with linezolid. Virulence was similar in strains with high vancomycin MIC (≥2 μg/mL) versus those with vancomycin MIC<2 μg/mL.
Conclusions: D. melanogaster is a potentially useful model host to study pathogenicity and response to antibiotic treatment in S. aureus. Our results imply that the attenuated virulence of PVL(+)/USA300 requires intact host innate immunity.
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http://dx.doi.org/10.1016/j.micpath.2012.11.012 | DOI Listing |
Biochem Biophys Res Commun
January 2025
Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan. Electronic address:
Epoxide hydrolases (EHs) play pivotal roles in detoxification, catabolism, and signaling by converting epoxides into diols and have been implicated in several diseases, such as cancers and diabetes. EH homologs in insects are designated as Juvenile hormone epoxide hydrolases (JHEHs) due to their catalytic activity toward Juvenile hormone (JH). However, the biological function of JHEHs has been controversial in the fruit fly Drosophila melanogaster.
View Article and Find Full Text PDFG3 (Bethesda)
January 2025
School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA.
As part of an ongoing effort to generate comprehensive resources for the experimental analysis of fourth chromosome genes in Drosophila melanogaster, the Fourth Chromosome Resource Project has used CRISPR mutagenesis with single guide RNAs to isolate mutations in 62 of the 80 fourth chromosome, protein-coding genes. These mutations were induced on a fourth chromosome bearing a basal FRT insertion to facilitate experimental approaches involving FLP recombinase-induced mitotic recombination. To permit straightforward comparisons among mutant stocks, most of the mutations were generated on isogenic fourth chromosomes, which were then crossed into a common genetic background.
View Article and Find Full Text PDFUnlabelled: The use of microcomputed tomography (Micro-CT) for imaging biological samples has burgeoned in the past decade, due to increased access to scanning platforms, ease of operation, isotropic three-dimensional image information, and the ability to derive accurate quantitative data. However, manual data analysis of Micro-CT images can be laborious and time intensive. Deep learning offers the ability to streamline this process, but historically has included caveats-namely, the need for a large amount of training data, which is often limited in many Micro-CT studies.
View Article and Find Full Text PDFGut microbiota are fundamental for healthy animal function, but the evidence that host function can be predicted from microbiota taxonomy remains equivocal, and natural populations remain understudied compared to laboratory animals. Paired analyses of covariation in microbiota and host parameters are powerful approaches to characterise host-microbiome relationships mechanistically, especially in wild populations of animals that are also lab models, enabling insight into the ecological basis of host function at molecular and cellular levels. The fruitfly is a preeminent model organism, amenable to field investigation by 'omic analyses.
View Article and Find Full Text PDFJ Exp Biol
January 2025
Department of Entomology, Cornell University, Ithaca, NY 14853, USA.
Bacterial infections can substantially impact host metabolic health as a result of the direct and indirect demands of sustaining an immune response and of nutrient piracy by the pathogen itself. Drosophila melanogaster and other insects that survive a sublethal bacterial infection often carry substantial pathogen burdens for the remainder of life. In this study, we asked whether these chronic infections exact metabolic costs for the host, and how these costs scale with the severity of chronic infection.
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