AEROBIC – ANAEROBIC CUTANEOUS MICROBIOTA OF HIDRADENITIS SUPPURATIVA. A CASE REPORT

Abstract

Hidradenitis suppurativa (HS) is a chronic inflammatory disease affecting intertriginous skin areas of young adults. Although HS was historically defined as an infectious disease, the role of microorganisms in its pathogenesis is now controversial. We investigated the lesion microbiota of a recently diagnosed 24-year-old male patient with axillary HS, who shared features of the metabolic syndrome. The microbiological analysis of the patient’s lesion was indicative of colonization with bacteria including aerobes – Staphylococcus (S.) aureus, S. lugdunensis, S. epidermidis, anaerobes – Anaerococcus (A.) octavius, and microaerophiles – Cutibacterium (C.) acnes; this last one was also isolated in monoculture from a patient's healthy skin control sample. In vitro antibiotic susceptibility evaluation revealed Methicillin-resistant S. aureus (MRSA) and highly susceptible S. lugdunensis and S. epidermidis. Profiles of A. octavius and C. acnes showed that both strains were susceptible to Vancomycin, Clindamycin, Doxycycline and Linezolid; the anaerobe was Benzylpenicillin-resistant and Tetracycline and the microaerophile was intrinsically Metronidazole-resistant. We conclude that the intralesional microbial diversity in this case shows low variety of species and similarities to healthy skin microbiota, although the presence of S. aureus, particularly MRSA, S. lugdunensis or C. acnes – frequently involved in chronic skin pathologies – may be relevant for the disease severity. MRSA carriage in the patient’s lesion represents a significant epidemiological risk for the healthcare environment. Antibiotic treatment in the early stages of HS should be administered with caution. Extended studies of HS microbiota could identify relevant colonization patterns for the outcome of the disease and offer important keys for selecting personalised, efficient therapeutic schemes. Keywords: hidradenitis suppurativa, cutaneous microbiome, bacterial pathogens, MRSA, Staphylococcus aureus, Cutibacterium acnes, anaerobes