Preparation and evaluation of a new combined conjugated vaccine against Klebsiella pneumonia and Pseudomonas aeruginosa.

AIMS: Lower respiratory tract infections (LRTIs) have been identified by the World Health Organization as the most deadly infectious diseases and a pervasive public health problem, causing increased hospital admissions, mortality and antibiotic use. This study aims to determine the most common and resistant bacteria that cause LRTIs and prepare an appropriate vaccine to reduce and prevent potential future infections. METHODS AND RESULTS: Our survey was conducted by collecting respiratory exudate specimens. The most predominant and resistant types were Klebsiella pneumonia and Pseudomonas aeruginosa. The lipopolysaccharides (LPS) were extracted using a modified hot phenol method to prepare the vaccine. The LPS were then activated and conjugated. The immunogenicity of the prepared singles and combined vaccines was determined through an in vivo assay using BALB/c mice. The prepared vaccine provided high protection against the lethal dose of both bacteria in mice. The combined vaccine shows a significant value in achieving high immunization. CONCLUSION: These findings demonstrate the potential of the bacterial LPS molecules to be used as effective vaccines. SIGNIFICANCE AND IMPACT OF STUDY: Developing an effective single and combined vaccine against P. aeruginosa and K. pneumonia can protect and reduce LRTI incidence.

Adipose mesenchymal stem cells combined with platelet-rich plasma accelerate diabetic wound healing by modulating the Notch pathway.

BACKGROUND: Diabetic foot ulceration is a serious chronic complication of diabetes mellitus characterized by high disability, mortality, and morbidity. Platelet-rich plasma (PRP) has been widely used for diabetic wound healing due to its high content of growth factors. However, its application is limited due to the rapid degradation of growth factors. The present study aimed to evaluate the efficacy of combined adipose-derived mesenchymal stem cells (ADSCs) and PRP therapy in promoting diabetic wound healing in relation to the Notch signaling pathway. METHODS: Albino rats were allocated into 6 groups [control (unwounded), sham (wounded but non-diabetic), diabetic, PRP-treated, ADSC-treated, and PRP+ADSCs-treated groups]. The effect of individual and combined therapy was evaluated by assessing wound closure rate, epidermal thickness, dermal collagen, and angiogenesis. Moreover, gene and protein expression of key elements of the Notch signaling pathway (Notch1, Delta-like canonical Notch ligand 4 (DLL4), Hairy Enhancer of Split-1 (Hes1), Hey1, Jagged-1), gene expression of angiogenic marker (vascular endothelial growth factor and stromal cell-derived factor 1) and epidermal stem cells (EPSCs) related gene (ß1 Integrin) were assessed. RESULTS: Our data showed better wound healing of PRP+ADSCs compared to their individual use after 7 and 14 days as the combined therapy caused reepithelialization and granulation tissue formation with a marked increase in area percentage of collagen, epidermal thickness, and angiogenesis. Moreover, Notch signaling was significantly downregulated, and EPSC proliferation and recruitment were enhanced compared to other treated groups and diabetic groups. CONCLUSIONS: These data demonstrated that PRP and ADSCs combined therapy significantly accelerated healing of diabetic wounds induced experimentally in rats via modulating the Notch pathway, promoting angiogenesis and EPSC proliferation.