Background: Tachyplesin III, an antimicrobial peptide (AMP), provides protection against multidrug-resistant (MDR) bacterial infections and shows cytotoxicity to mammalian cells. Mixed bacterial infections, of which P. aeruginosa plus A. baumannii is the most common and dangerous combination, are critical contributors to the morbidity and mortality of long-term in-hospital respiratory medicine patients. Therefore, the development of effective therapeutic approaches to mixed bacterial infections is urgently needed. Methods and results: In this study, we demonstrated that compared with individual infections, mixed infections with MDR bacteria P. aeruginosa and A. baumannii cause more serious diseases, with increased pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) and chemokines (MCP-1/MIP-2) and reduced mouse survival. In vitro treatment with Tachyplesin III enhanced phagocytosis in a mouse alveolar macrophage cell line (MH-S). Strikingly, in vivo, Tachyplesin III demonstrated a potential role against mixed-MDR bacterial coinfection. The bacterial burden in bronchoalveolar lavage fluid (BALF) was significantly reduced in the Tachyplesin III-treated group. In addition, a systemic reduction in pro-inflammatory cytokines and decreased lung injury occurred with Tachyplesin III therapy. Conclusion: Therefore, our study demonstrated that Tachyplesin III represents a potential therapeutic treatment against mixed-MDR bacterial infection in vivo, which sheds light on the development of therapeutic strategies against mixed-MDR bacterial infections.

A novel blue azo-anthraquinone reactive dye was evaluated in the dyeing of cotton by using a dip–pad–steam process. Dyeing method and properties were examined in detail and the results showed that the dyeing method consisting of dye concentration of 25 g/L, sodium carbonate of 12 g/L, dipping time of 3 min and steaming time of 30 min was the most effective when a conventional “one-dip–one-nip” process was used. The fixation of the dyes on cotton could reach up to 93.4%, the wash and rub fastness both reached grade 4 above, and the light fastness reached grade 4–5 above. Such colored cotton showed very close colorimetric properties.

New types of poly(vinylamine-co-acrylic acid) macromolecule dyes were designed and synthesized based on poly(vinylamine-co-acrylic acid) and reactive dyes. The structures of the synthesized dyes were characterized by ultraviolet-visible spectroscopy, infrared spectroscopy, proton nuclear magnetic resonance and thin layer chromatography. They were applied for dyeing cotton fibers and high fixations were achieved due to their reactive abilities. The dyed samples showed excellent fastness to washing and rubbing and the light fastness of red, blue and yellow poly(vinylamine-co-acrylic acid) dye could reach grades 3–4, 4 and 6–7, respectively.