Introduction: Psoriasis is a lifelong inflammatory disease that involves the skin, joints, cardiovascular system, and CNS. Its outward symptoms include redness, peeling, and itching. This disease is known as an autoimmune disorder that can affect the quality of life.One of the important aspects in understanding this disease is to examine the changes in the skin microbiome of psoriasis patients.Staphylococcus aureus is a spherical gram-positive bacterium that usually exists in the skin and mucous membranes of humans, and approximately 10-20% of people carry it without symptoms. Recent research has shown that the skin microbiome plays an important role in skin health and diseases. Staphylococcus aureus, which is part of the normal flora of the skin, acts as an opportunistic pathogen, which means that in certain conditions such as damage to the skin and weak immune system, it can lead to disease.It is thought that the presence of Staphylococcus aureus contributes to the inflammatory processes associated with psoriasis by affecting the Th1/Th17 axis.Considering this issue, the aim of this study is to investigate the colonization rate of Staphylococcus aureus on the skin of patients with psoriasis compared to healthy control subjects. This study can provide valuable information for the development of new treatment methods and prevention strategies for skin infection.
Methods: This cross-sectional study was designed with the aim of investigating the colonization rate of Staphylococcus aureus bacteria on the skin of patients compared to control subjects. The participants in this study included 21 patients with psoriasis who visited the skin clinic of Tajrish Hospital located in Tehran. 21 healthy individuals who did not have psoriasis and matched the patient group in terms of age and sex. A skin sample was taken from the forearm of a person using a sterile swab from 5 cm2 and inoculated into liquid BHI culture medium and incubated for 48 hours at 37°C. After DNA extraction by boiling method and with the help of specific primers, PCR reaction was performed to detect the presence or absence of Staphylococcus aureus. The samples that were positive for the presence of Staphylococcus aureus were cultured in the special mannitol salt agar culture medium after preparation of serial dilutions. The obtained data were analyzed using SPSS version 26 software.
Results: In microbial cultures, 38% (8 out of 21 patients) of the samples of psoriasis patients led to the growth of Staphylococcus aureus, while this figure was only 5.9% (2 out of 21 healthy people) in the control group.
The Mann-Whitney test showed that the number of Staphylococcus aureus clones in the skin of patients with psoriasis was significantly higher than that of the control group (p=0.04). This increase in the number of clones was observed especially in the inflamed areas of the patients' skin.
Conclusion: The results showed that patients with psoriasis have significant changes in the frequency of Staphylococcus aureus compared to the control group. An increase in Staphylococcus aureus colonization can play an important role in aggravating the clinical symptoms and inflammation associated with psoriasis. It can also be used as a potential biomarker to assess the severity of the disease. According to the findings of this study, it is suggested that more research be done on the effect of therapeutic interventions on the change of staphylococcus aureus colonization in the chest of psoriasis patients. Also, a better understanding of the interactions of staphylococcus aureus in the skin microbiome and the immune system may lead to the development of new therapeutic strategies. Help to manage psoriasis.Finally, this study emphasizes the importance of carefully investigating the increase in Staphylococcus aureus colonization in the skin in order to better understand the pathogenesis of psoriasis and improve the quality of life of patients.