Acta Dermato-Venereologica 98-9CompleteContent | Page 17

898 SHORT COMMUNICATION Chlamydiales Bacterial Sequences in Lesional and Healthy Skin of Patients with Parapsoriasis Kati HOKYNAR 1 , Alexander SALAVA 2 , Eero VESTERINEN 3,4 , Antti LAUERMA 2 , Annamari RANKI 2 and Mirja PUOLAKKAINEN 1 Department of Virology and 4 Spatial Foodweb Ecology Group, The Faculty of Agriculture and Forestry, University of Helsinki, PO Box 21, FIN-00014 Helsinki, 2 Department of Dermatology, Allergology and Venereal Diseases, University of Helsinki and Center of Inflammation, Helsinki University Hospital, Helsinki, and 3 Biodiversity Unit, University of Turku, Turku, Finland. E-mail: [email protected] 1 Accepted Jun 26, 2018; Epub ahead of print Jun 29, 2018 Chlamydia-related bacteria represent a diverse group of bacteria within the order Chlamydiales that have been detected ubiquitously in various environmental samples, such as soil and water, in animals, and also in humans (1–6). We recently demonstrated the presence of Chlamydiales DNA in human skin (7). Chlamydiales DNA could be detected in > 50% of all the skin biopsies studied, but the prevalence was higher and the type range was wider in biopsies from individuals with a suspected tick-related skin condition, compared with biopsies from healthy skin (8). Parapsoriasis is part of the continuum of cutaneous lymphoproliferative disorders of unknown aetiology and is clinically classified into small-plaque parapsoriasis (SPP) and large-plaque parapsoriasis (LPP) (9). This study examined the prevalence, distribution and relative abundance of Chlamydiales DNA in skin biopsies and skin swab samples, both from lesional and contralateral healthy skin, from 13 patients with parapsoriasis (6 SPP, 7 LPP; see Appendix S1 1 ). The clinical characteristics and skin microbiome data for these patients have been reported earlier (10). RESULTS No Chlamydiales sequences were detected among the previous microbiome data (10) when searched speci- fically for Chlamydiales sequences (Appendix S1 1 ). Nonetheless, using a Chlamydiales-specific method, 12/13 (92%) patients with SPP or LPP had Chlamydiales DNA in the skin swabs taken from the lesional site and 11 (85%) in swabs from the contralateral healthy skin. The prevalence of Chlamydiales DNA was lower in the biopsy specimens than in the swab specimens: 77% and 54% of the patients had Chlamydiales DNA in the biopsies of lesional and control skin areas, respectively. In swabs from both lesional and healthy skin, the majority of the Chlamydiales sequences remained un- classified (Table I and Table SI 1 ). In BLAST analysis, Parachlamydiaceae (24%), Criblamydiaceae (18%) and Simkaniaceae (6–12%) were the closest established Chla- mydiales families (with ≥ 90% identity) for sequences present in swabs from both healthy skin and parapsoriasis lesions (Table I and Table SI 1 ). In skin biopsies, Parachla- https://www.medicaljournals.se/acta/content/abstract/10.2340/00015555-2999 1 doi: 10.2340/00015555-2999 Acta Derm Venereol 2018; 98: 898–899 Table I. Chlamydiales families in the sequenced pan-Chlamydiales PCR-positive skin samples PanChlamydiales-PCR and sequencing Swab lesion n (%) Swab control a n (%) Biopsy lesion n (%) Biopsy control a n (%) Patients with positive results 12 (92) 11 (85) 10 (77) 7 (54) Positive PCR results b Readable Chlamydiales sequence Parachlamydiaceae Criblamydiaceae Simkaniaceae Chlamydiaceae 19 17 4 (24) 3 (18) 1 (6) 0 19 17 4 (24) 3 (18) 2 (12) 1 (6) 11 9 4 (44) 3 (33) 0 0 7 7 3 (43) 0 2 (29) 0 Unclassified Chlamydiales c 9 (53) 7 (41) 2 (22) 2 (29) Unclassified Chlamydiales were prevalent in skin. Members of the Parachlamydiaceae and Criblamydiaceae families were the most common lineages a Control: a specimen of healthy skin from the contralateral side of body. b Swab specimens (2 from each patient) and biopsies were tested in duplicate. c Chlamydiales sequences that could not be classified into currently established families. mydiaceae sequences were detected in both healthy and parapsoriatic skin (up to 44% of all sequences), while Criblamydiaceae sequences were detected only in le- sional (33%) and Simkaniaceae (29%) only in healthy skin biopsies. No difference in the sequence heterogene- ity was observed between SPP and LPP. Interestingly, using sequence analysis, heterogeneous Chlamydiales sequences were seen in the duplicate samples (both swabs and biopsies), suggesting that several types of Chla- mydiales can be present simultaneously in skin. The ΔCt values (Ct panchlamydiales – Ct betaglobin ) were smaller in swabs than in biopsies, indicating that the relative quantity of Chlamydiales DNA was higher in swab samples than in biopsy samples (p < 0.0001) (Fig. S1 1 ). DISCUSSION This study confirmed that skin contains detectable amounts of Chlamydiales DNA. Earlier, we showed that skin microbiomes in parapsoriasis lesions and healthy skin were very similar, suggesting that parapsoriasis is not associated with alterations in the composition of patient’s cutaneous bacterial community, but interper- sonal variation was significant (10). In that study, Chla- mydiales DNA was not detected, as the 16S rRNA gene sequences of the Chlamydiales order differ from those of other bacteria, and primers used in pan-bacterial PCRs often fail in detection of Chlamydiales (2). Indeed, Chla- mydiales DNA was frequently detected in skin samples, when Chlamydiales-specific primers were used. It is also possible that the quantity of Chlamydiales sequences is low and outnumbered by the other bacteria. This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2018 Acta Dermato-Venereologica.