Project description:Cutibacterium acnes (C. acnes) is a ubiquitous skin commensal bacterium that is generally well tolerated by the immune system. Different strain-types of C. acnes have been reported to be enriched on patients with acne. To understand if these strain-types contribute to skin inflammation, we generated a library of over 200 C. acnes isolates from skin swabs of healthy and acne subjects and assessed their strain-level identity and inflammatory potential. Phylotype II K-type strains were more frequent on healthy and acne non-lesional skin compared to lesional. Phylotype IA-1 C-type strains were dominant on acne lesional skin but absent from healthy. Measurement of host cytokine responses from C. acnes supernatant revealed neither strain-type nor skin-type association predicted inflammatory potential. However, differential proinflammatory responses were induced from identical strain-types, but these differences were not attributable to protease, short chain fatty acid or porphyrin production. Instead, whole genome sequencing revealed the presence of a linear plasmid in high inflammatory strain-types. Intradermal injection of C. acnes in mouse skin revealed a plasmid-associated inflammatory response in dermal fibroblasts, revealed by single-cell RNA sequencing. We conclude that C. acnes strain-type is not sufficient to predict inflammation but other virulence factors including a plasmid may contribute to disease.
2023-08-18 | GSE211279 | GEO
Project description:Staphylococcus saccharolyticus associated with prosthetic joint infections
Project description:Proprionibacterium acnes is a Gram positive bacterium found ubiquitously on human skin, where it is typically considered to assume a commensal relationship with its host. However, it is also closely associated with the skin condition acne vulgaris. More controversially, it has a postulated involvement in infections of implanted prosthetic devices and has been isolated from malignant prostate tissues. The role of P. acnes in these pathologies remains undetermined, although both bacterial and host factors are implicated. By microarray analysis, we have identified fundamental differences in the global transcriptional profiles of keratinocyte and prostate cells to P. acnes infection. Notably, P. acnes infection of the keratinocyte cell line, HaCaT, elicited a robust, but acute inflammatory response. By contrast, the inflammatory response of the prostate cell line, RWPE1, was delayed and persisted for longer times. Immunofluorescence and electron microscopy revealed higher numbers of internalized P. acnes bacteria in RWPE1 cells, which could still be detected intracellularly three weeks post infection. This contrasted with HaCaT cells, which P. acnes largely failed to invade. Moreover, P. acnes induced a delayed, sustained activation of NFM-NM-:B in RWPE1 cells, which was absent in HaCaT cells. Further characterization of the host-cell response to infection revealed that the intermediate filament protein, vimentin, was a key determinant of P. acnes invasion, persistence and inflammatory profile in RWPE1 cells. siRNA mediated knock down of vimentin in RWPE1 cells attenuated bacterial invasion and the inflammatory response to infection; similarly, overexpression of vimentin in HaCaT cells increased bacterial invasion. We conclude that vimentin-dependent host-tissue tropism, in part, determines P. acnes invasion and inflammatory capacity. This could contribute to P. acnes pathology at non-skin infection sites. Microarray experiments were performed as dual-color hybridizations. In order to compensate specific effects of the dyes and to ensure statistically relevant data analysis, a color-swap dye-reversal was performed.
Project description:Recently the membrane vesicles (MVs) production has been observed in Gram-positive bacterium, Cutibacterium acnes (C. acnes). In order to explore the mechanism of antibiotic resistance and the virulent components within the C. acnes-derived MVs, we isolated MVs from the clinical C. acnes, which were sensitive or resistant to antibiotics erythromycin and clindamycin. With the LC-MS/MS method, we detected several lipases, virulent factors and cell division protein differentially expressed between the sensitive and the resistant C. acnes-derived MVs.
2022-05-20 | PXD025460 | Pride
Project description:Comparison of Cutibacterium acnes Clinical Isolates
Project description:Infection is a devastating post-surgical complication, often necessitating additional procedures and prolonged antibiotic therapy. This is especially relevant for craniotomy and prosthetic joint infections, both of which are characterized by biofilm formation on the bone or implant surface, respectively, with S. aureus representing a primary cause. The effectiveness of immune responses to these infections is predicated on both host- and pathogen-derived signals in the infection microenvironment. However, the extent to which these signals differ across distinct tissue niches and influence immune function remains relatively unknown. Using mouse models of S. aureus craniotomy and prosthetic joint infection complemented with patient samples from both infectious modalities, we show profound metabolomic, transcriptomic, and functional differences that are dependent on tissue niche. These signatures were both spatially and temporally distinct, differing not only between surgical site infections but evolving over time within a single model. These findings highlight the unique immune attributes of biofilms that are heavily influenced by the local tissue microenvironment, which will likely have important implications when designing therapeutic approaches to target specific infections.