Malassezia yeasts activate the NLRP3 inflammasome in antigen‐presenting cells via Syk‐kinase signalling

Although being a normal part of the skin flora, yeasts of the genus Malassezia are associated with several common dermatologic conditions including pityriasis versicolour, seborrhoeic dermatitis (SD), folliculitis, atopic eczema/dermatitis (AE/AD) and dandruff. While Malassezia spp. are aetiological agents of pityriasis versicolour, a causal role of Malassezia spp. in AE/AD and SD remains to be established. Previous reports have shown that fungi such as Candida albicans and Aspergillus fumigatus are able to efficiently activate the NLRP3 inflammasome leading to robust secretion of the pro‐inflammatory cytokine IL‐1β. To date, innate immune responses to Malassezia spp. are not well characterized. Here, we show that different Malassezia species could induce NLRP3 inflammasome activation and subsequent IL‐1β secretion in human antigen‐presenting cells. In contrast, keratinocytes were not able to secrete IL‐1β when exposed to Malassezia spp. Moreover, we demonstrate that IL‐1β secretion in antigen‐presenting cells was dependent on Syk‐kinase signalling. Our results identify Malassezia spp. as potential strong inducers of pro‐inflammatory responses when taken up by antigen‐presenting cells and identify C‐type lectin receptors and the NLRP3 inflammasome as crucial actors in this process.     

Initial prevalence of anal human papilloma virus infection in liver transplant recipients

Although liver transplant recipients are at increased risk of human papilloma virus (HPV)‐related anal cancer, limited data are available regarding the initial prevalence of anal HPV infection in this population. Anal swabs collected from 50 liver transplant recipients within the first three postoperative weeks were subjected to real‐time polymerase chain reaction for detection of the four HPV genotypes: 6, 11, 16, and 18. Predictors of any, low‐risk, and high‐risk anal HPV infection were evaluated. Overall, the prevalence of any anal HPV infection was 18.0%, with the corresponding rates for high‐ and low‐risk HPV genotypes being 8.0% and 10.0%, respectively. Infection with any type of anal HPV was higher in patients with hepatitis B virus (HBV) infection (P = 0.027), ≥3 sexual partners (P = 0.031), and alcoholic liver disease (P = 0.063). HBV infection was the only factor significantly associated with high‐risk HPV infection (P = 0.038). Male sex (P = 0.050), age ≥52 years (P = 0.016), ≥30 sexual partners (P = 0.003), age at first intercourse ≤18 years (P = 0.045), and time since first intercourse ≥38 years (P = 0.012) were identified as predictors of low‐risk HPV infection. These results indicate that HPV vaccination of liver transplant candidates and screening for anal HPV infection in high‐risk groups should be considered.     

ALIS‐FLP: Amplified ligation selected fragment‐length polymorphism method for microbial genotyping

A DNA fingerprinting method known as ALIS‐FLP (amplified ligation selected fragment‐length polymorphism) has been developed for selective and specific amplification of restriction fragments from TspRI restriction endonuclease digested genomic DNA. The method is similar to AFLP, but differs in that only one specific restriction enzyme (TspRI) is used. The cohesive ends of the DNA fragments are ligated with two types of oligonucleotide. A long oligonucleotide containing the primer site and the specific 9 nt 3 prime end, which is complementary to specific 9 nt, cohesive 3 prime end of the TspRI genomic DNA fragment, and a short, degenerated, oligonucleotide covering the remaining TspRI cohesive ends. Other cohesive ends are covered by a short degenerated oligonucleotide lacking the primer site. The ligation mixture is used as a template for amplification using a single primer corresponding to the 5 prime end of the long, specific oligonucleotide. The selection of TspRI digested genomic DNA fragments for amplification is achieved by sequence selective ligation of the specific long oligonucleotide carrying the primer site to both ends of the specific target fragment. This technique allows for differentiation of the organisms without previous knowledge of their DNA sequence. The usefulness of the method is confirmed by genotyping of 70 previously characterized clinical E. coli isolates. The grouping obtained was identical to the results of REA‐PFGE. Versatility of the method is highlighted, i.e. its combining the advantages of the AFLP technique with a simple, rapid and cheap polymerase chain reaction product detection method.     

Seemingly healthy skin in atopic dermatitis: observations with the use of high‐frequency ultrasonography,preliminary study

Background: Atopic dermatitis (AD) is a chronic, relapsing skin disorder which is strictly determined by the epidermal barrier function. In previous studies, there is conclusive evidence that normal‐looking, nonlesional skin presents meaningful barrier function defect and a sub‐clinical eczematous skin reaction. Aim: The authors intended to visualize nonlesional AD skin with the use of high frequency ultrasonography to show that the normal‐looking, nonlesional skin may present significant abnormalities in USG examination. Methods: We have performed analysis with the use of high‐frequency 20 MHz skin sonography in the cases of 15 AD patients of the Department of Dermatology, Medical University, Poznań, Poland. The clinical score has been evaluated on the basis of W‐AZS index and EASI. The results were presented in the form of ultrasonographic images. Results: High frequency ultrasonography revealed an echopoor band within nonlesional skin of six (40%) examined AD patients and in all cases within skin lesions. Conclusion: Our results indicate the significant role of skin ultrasonography in the complete clinical evaluation of patients with AD, which may serve as an element in selection of the most appropriate topical treatment. An echopoor band beneath the echo entry within nonlesional skin of some AD patients may reflect subclinical eczematous reaction and the readiness for the development of typical skin lesions. For this purpose, we suggest to name an intact skin in AD as seemingly healthy skin.