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Klebsiella pneumoniae is an opportunistic pathogen and it can cause human mucosal lesions through the intestine, leading to bacteremia and abscess formation in liver and spleen. Previous studies have shown that K. pneumoniae can enter or cross cells through the intestinal epithelium, but the mechanism is unknown. In this study, we treated the intestinal epithelial cell line Caco-2 with KP1195, a clinically isolated strain with high adhesion and invasion of intestinal epithelial cells. The results showed that the treatment of K. pneumoniae could increase the expression of integrin gene and further disrupt the changes of cytoskeleton. Treating Caco-2 with cytoskeletal inhibitor cytorelaxin D can significantly increase the efficiency of K. pneumoniae invading Caco-2 cells. These data suggest that disruption of the cytoskeleton through integrins may be one of the mechanisms by which K. pneumoniae increases intracellular invasion. This study provides a theoretical basis for further understanding of the mechanism of K. pneumoniae entering intestinal epithelial cells. [ABSTRACT FROM AUTHOR]

By studying the expression in patients and cell modeling in vitro, antimicrobial peptides for Klebsiella were screened. Killing curve and membrane permeability experiments are used to study the antibacterial effect of antimicrobial peptides in vitro. Cytotoxicity‐related indicators including lipopolysaccharide (LPS), capsule polysaccharide (CPS), and outer membrane protein expression were measured. Intranasal inoculation of pneumoconiosis was used to construct a mouse infection model, and the survival rate and cytokine expression level were tested. Human neutrophil peptide 1 (HNP‐1) showed a significant antibacterial effect, which improved the permeability of the outer membrane of K. pneumoniae. Moreover, HNP‐1 decreased LPS, CPS content, and outer membrane proteins. K. pneumoniae infection decreased antimicrobial peptide, oxidative stress, and autophagy‐related genes, while HNP‐1 increased these genes. After coculture with macrophages, the endocytosis of macrophages is enhanced and the bacterial load is greater in the K. pneumoniae + peptide group. Besides, higher levels of pp38 and pp65 in the K. pneumoniae + peptide group. HNP‐1 rescued the cytotoxicity induced by K. pneumoniae. The survival rate is significantly improved after K. pneumoniae is treated by HNP‐1. All cytokines in the peptide group were significantly higher. HNP‐1 promotes immune sterilization by reducing the virulence of multidrug‐resistant K. pneumoniae and increasing the ability of macrophages. [ABSTRACT FROM AUTHOR]

Context: Early intervention and treatment are key measures for tuberculosis (TB) prevention and control, making early, rapid, and accurate diagnostic methods crucial. The Liquid-solid (Biphasic) rapid cultures is a novel tool for the differential diagnosis of tuberculosis., Objective: The study intended to evaluate the value of the biphasic cultures by comparing it to the acid-fast staining and liquid cultures, which have been the traditional gold-standard technology, to determine its value in the diagnosis of TB., Design: The research team conducted an experimental study., Setting: The study took place at the Affiliated Wuxi Fifth Hospital of Jiangnan University in Wuxi, China., Participants: Participants were 221 patients with suspected pulmonary tuberculosis who had been admitted to the hospital between July 2020 and December 2021., Outcome Measures: Using three methods-liquid-solid (biphasic) culture, acid-fast staining, and mycobacterial growth indicator tube (MGIT) 960 liquid culture, the research team tested participants' sputum samples: (1) for sensitivity; (2) for time to positive culture results, and (3) for differential diagnosis., Results: The biphasic culture's sensitivity was significantly higher than that of acid-fast staining, (P = .0003), and no significant difference existed between it and the MGIT 960 liquid cultures. The biphasic cultures's mean time to positivity was significantly shorter than that of the MGIT 960 liquid culture at the intervals 11-20 d (P < .0001) and 21-35 days (P = .0001). Moreover, the biphasic cultures could preliminarily differentiate nontuberculous mycobacteria (NTM) from mycobacterium tuberculosis (MTB), which is a significant advantage in tuberculosis diagnosis., Conclusions: This study highlights the potential of a biphasic culture as a reliable tool for the rapid differential diagnosis of tuberculosis, with a faster detection cycle and a higher sensitivity than conventional methods. The biphasic cultures is a valuable addition to the tuberculosis diagnostic armamentarium and can help improve patients' outcomes by enabling earlier diagnosis and treatments.