فعالیت درماتیتی پدرین و جداسازی باکتری هم‌زیست مرتبط با بیوسنتز آن از سوسک پدروس فوسیپس استان مازندران

Background and purpose: Pederin is a vesicant toxic amide which is found in the haemolymph of the Paederus beetles. It has been considered in studies of cancer treatment with cytotoxicity activity. The present study aimed to review the pederin dermatitis activity from Paederus fuscipes (P. fuscipes) beetles and isolation of symbiotic bacterium associated with pederin biosynthesis. Materials and methods: The P. fuscipes beetles were collected from various areas of Mazandaran, Iran. For extraction of pederin and isolation of symbiotic bacterium associated with pederin synthesis, the smashed Paederus was transferred into Pseudomonas isolation medium. The presence of pederin in the extracted crude from beetles and isolated growth culture was confirmed using thin-layer chromatography (TLC) then dermatitis activity was examined on laboratory rats. Results: A pink spot with Rf = 0.22 was shown on silica gel plate of TLC. This result demonstrated the existence of pederin in the extracted crude. In addition, the results of pederin bioactivity on laboratory rats indicated that the dermatitis effect appeared after 24 hours with swelling, redness, skin secretion and epidermal necrosis. For the first time, a symbiotic bacterium associated with pederin synthesis was isolated from the beetle P. fuscipes. The bacterium with greenish pigment was named as isolate MH1. The results of morphological and physiological characteristics of isolate MH1 indicated that this bacterium belonged to Pseudomonas sp. Moreover, 16S rRNA sequencing and phylogenetic analyses exhibited that MH1 was similar to P. aeruginosa with 99% homology. In addition, TLC analysis of growth medium demonstrated that MH1 was able to synthesis pederin in vitro. Conclusion: The results of this study revealed that the haemolymph of P. fuscipes beetles of Mazandaran contains pederin with dermatitis activity. In addition, the growth of isolated bacterium associated with pederin biosynthesis could be an opportunity for the production of pederin in a large scale then used for cancer treatment researches.