BACKGROUND: Forest frog is a rare medicinal animal in China, but the skin of forest frog is waste after Oviductus Ranae production. The forest frog skin is rich of collagen, and is large in quantity without pollution and disease risk. So the forest frog skin has potential to be developed into collagen sponge; however, there is no research on collagen sponge preparation as yet.OBJECTIVE: To optimize the preparation of collagen sponge from forest frog skin, and to investigate the physical properties and in vitro cell compatibility.METHODS: Chitosan and glutaraldehyde were used to modify collagen sponge from forest frog skin. Chitosan/collagen (w/w) (1:1, 1:2, 1:4) and glutaraldehyde concentration (1%, 1.5% and 2%) were selected as the experimental factors.The significant water absorbency, mechanical properties and thermal denaturation temperature were chosen as the indexes. Using the orthogonal experimental design, we optimized collagen sponge preparation process. We also investigated the in vitro cell compatibility and surface morphology of the collagen sponge. The nine kinds of collagen sponges from forest frog skins were co-cultured with human foreskin fibroblasts to detect cell proliferation.RESULTS AND CONCLUSION: When the chitosan/collagen was 1:1 and the glutaraldehyde concentration was 1%, we could get the collagen sponge with ideal water absorbency (water absorption capacity=5.22), mechanical properties (elongation at break=10.96%) and thermal denaturation temperature (81.24 ℃). The aperture of the forest frog skin collagen sponge was 200-400 μm, and the pores were consistent in the size and arranged regularly. Except the chitosan/collagen of 1:4 and the glutaraldehyde concentration of 1% or 5%, all kinds of forest frog skin collagen sponges could promote the viability of human foreskin fibroblasts and exerted benefits to cell viability and growth. To conclude,the forest frog skin collagen sponge has good biocompatibility and apparent morphology, in aggreement with the requirements of biological materials.

Two types of Mycobacterium abscesses (Mab) were found in sputum from a patient with severe pneumonia in May 2020. One was Mycobacteriumabscessus with smooth morphology (Mab S), the other was Mycobacteriumabscessus with rough morphology (Mab R). Both of them were compared and drug susceptibility testing were performed to provide clinical scientific diagnosis and treatment. Morphology, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S rRNA were used to analyze Mab S and Mab R, phylogenetic evolution tree was constructed by gene sequence alignment for homology, proportion and broth drug test were used for in vitro drug sensitivity test. There were morphological differences between Mab S and Mab R. MALDI-TOF MS analysis showed that there were 223 protein peaks in Mab R and 147 protein peaks in Mab S. Mab S contained 1 397 bp and Mab R contained 1 402 bp as 16s rRNA gene sequencing revealed. Drug susceptibility testing showed that both of them were almost resistant to all antituberculosis drugs, but sensitive to most of antibiotics. Mab S and Mab R were not only different in manifestations, but also in protein and gene comparison. Both of them were generally resistant to antituberculosis drugs. Antibiotic combined therapy has been confirmed to be an effective treatment in clinic.