We have for the first time visualized different P. acnes phylotypes in macrocolonies/biofilms in sebaceous follicles of skin biopsies. Our results support the hypothesis that P. acnes can play a role in the pathogenesis of acne as acne samples showed a higher prevalence of follicular P. acnes colonization, both in terms of follicles containing P. acnes and the greater numbers of bacteria in macrocolonies/biofilms than in control samples.

Colorectal cancer (CRC) is the second most common cause of cancer death in the western world. An effective screening program leading to early detection of disease would severely reduce the mortality of CRC. Alterations in the gut microbiota have been linked to CRC, but the potential of microbial markers for use in CRC screening has been largely unstudied. We used a nested case–control study of 238 study subjects to explore the use of microbial markers for clbA+ bacteria harboring the pks pathogenicity island, afa‐C+ diffusely adherent Escherichia coli harboring the afa‐1 operon, and Fusobacterium nucleatum in stool as potential screening markers for CRC. We found that individual markers for clbA+ bacteria and F. nucleatum were more abundant in stool of patients with CRC, and could predict cancer with a relatively high specificity (81.5% and 76.9%, respectively) and with a sensitivity of 56.4% and 69.2%, respectively. In a combined test of clbA+ bacteria and F. nucleatum, CRC was detected with a specificity of 63.1% and a sensitivity of 84.6%. Our findings support a potential value of microbial factors in stool as putative noninvasive biomarkers for CRC detection. We propose that microbial markers may represent an important future screening strategy for CRC, selecting patients with a “high‐risk” microbial pattern to other further diagnostic procedures such as colonoscopy.

BackgroundThe conversion of soluble peptides and proteins into polymeric amyloid structures is a hallmark of many age-related degenerative disorders, including Alzheimer's disease, type II diabetes and a variety of systemic amyloidoses. We report here that amyloid formation is linked to another major age-related phenomenon − prostate tissue remodelling in middle-aged and elderly men.Methodology/Principal FindingsBy using multidisciplinary analysis of corpora amylacea inclusions in prostate glands of patients diagnosed with prostate cancer we have revealed that their major components are the amyloid forms of S100A8 and S100A9 proteins associated with numerous inflammatory conditions and types of cancer. In prostate protease rich environment the amyloids are stabilized by dystrophic calcification and lateral thickening. We have demonstrated that material closely resembling CA can be produced from S100A8/A9 in vitro under native and acidic conditions and shows the characters of amyloids. This process is facilitated by calcium or zinc, both of which are abundant in ex vivo inclusions. These observations were supported by computational analysis of the S100A8/A9 calcium-dependent aggregation propensity profiles. We found DNA and proteins from Escherichia coli in CA bodies, suggesting that their formation is likely to be associated with bacterial infection. CA inclusions were also accompanied by the activation of macrophages and by an increase in the concentration of S100A8/A9 in the surrounding tissues, indicating inflammatory reactions.Conclusions/SignificanceThese findings, taken together, suggest a link between bacterial infection, inflammation and amyloid deposition of pro-inflammatory proteins S100A8/A9 in the prostate gland, such that a self-perpetuating cycle can be triggered and may increase the risk of malignancy in the ageing prostate. The results provide strong support for the prediction that the generic ability of polypeptide chains to convert into amyloids could lead to their involvement in an increasing number of otherwise apparently unrelated diseases, particularly those associated with ageing.

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Prostate tissues from patients with prostate cancer and benign prostatic hyperplasia (BPH) frequently contain histological inflammation, and a proportion of these patients show evidence of Propionibacterium acnes infection in the prostate gland. We developed a multicolor fluorescent in situ hybridization (FISH) assay targeting P. acnes 23S rRNA along with a 14-kb region of the P. acnes genome. This assay was used to analyze prostate tissues from patients with prostate cancer and BPH. P. acnes infection of the prostate gland was demonstrated in prostatic tissue in 5 of 10 randomly selected prostate cancer patients. FISH analysis and confocal laser microscopy imaging revealed intracellular localization and stromal biofilmlike aggregates as common forms of P. acnes infection in prostate tissues from both prostate cancer and BPH patients. A sequential analysis of prostate tissue from individual patients suggested that P. acnes can persist for up to 6 years in the prostate gland. These results indicate that P. acnes can establish a persistent infection in the prostate gland. Further study is needed to clarify the link between this bacterium and prostatic inflammation which may contribute to the development of BPH and prostate cancer.Clinical benign prostatic hyperplasia (BPH) occurs in half of all men by the age of 80 years (20), while prostate cancer is a leading cause of morbidity and death among men in the United States and Western Europe (13). Chronic or recurrent inflammation has been implicated in the development and progression of both BPH (20) and prostate cancer (9,24,25,30), and various degrees of histological inflammation are seen in the majority of prostate tissue specimens examined. The possibility of an infectious etiology for this prostatic inflammation has been raised in the context of both BPH (20) and prostate cancer, although the accumulation of a larger amount of evidence supports this hypothesis for the latter. For example, epidemiological studies have reported an increased risk of prostate cancer in patients with a history of sexually transmitted infections (29,31,32). The genetic signatures of bacteria were found in prostate tissues from 21 of 107 patients with prostate cancer (21). Moreover, a positive correlation between prostatic inflammation and the detection of bacterial 16S rRNA gene sequences in tissue specimens obtained by radical prostatectomy has been reported (16).Recently, a single bacterial species, Propionibacterium acnes, has been shown to infect a considerable proportion (35%) of prostate glands removed at radical prostatectomy (6). Moreover, the presence of P. acnes was strongly correlated with histological inflammation, suggesting that this bacterium might be linked to cancer development. The possible involvement of P. acnes in prostate pathology was further highlighted by the detection of P. acnes 16S rRNA gene sequences in BPH tissues, with a positive association between the detection of P. acnes DNA and subsequent prostate cancer development reported (1). We have developed ...