![]() ![]() Several studies have demonstrated that S. Lysostaphin cleaves pentaglycine bridges in staphylococci, thereby hydrolyzing the cell wall and lysing the bacteria ( Grundling and Schneewind, 2006 Francius et al., 2008). Lysostaphin is a glycylglycine endopeptidase secreted by Staphylococcus simulans. Inhibition of pentaglycine bridge formation leads to a substantial decrease in peptidoglycan cross-links and renders the bacteria highly resistant to lysostaphin ( Rohrer et al., 1999). aureus is peptidoglycan, which is cross-linked by pentaglycine bridges that help maintain the integrity of the cell wall ( Labischinski, 1992 Monteiro et al., 2019). The major structural component of the cell wall of S. Therefore, glucose is known to be involved in cell-wall synthesis in S. aureus are usually associated with thickening of the cell wall ( Bertsche et al., 2011 Bayer et al., 2013). Daptomycin is a lipopeptide antimicrobial agent that hinders peptidoglycan synthesis in the bacterial cell wall. aureus, which is independent of the proton motive force and unaffected by physiological changes in pH ( Prax et al., 2016). In addition, glucose enhances the killing efficiency of daptomycin against S. aureus and is suppressed in tryptic soy broth (TSB) medium containing an excess of glucose ( Yamada and Matsumoto, 1986). Protein A is a major component of the cell wall of S. However, surface proteins, such as protein A, promote biofilm development in the absence of PIA exopolysaccharide ( Merino et al., 2009). The matrix within biofilm often consists of polysaccharide intercellular adhesin (PIA). Staphylococcus aureus grew in medium usually forms weak biofilm, and addition of glucose to growth medium is a common practice to simulate biofilm formation in vitro ( You et al., 2014). aureus is the most frequent pathogen isolated from diabetic foot ulcers, but the properties of this bacterium under high glucose conditions remain unclear. ![]() However, high glucose usually induces endothelial and renal cytotoxicity in diabetic patients ( Gao et al., 2015 Yi et al., 2018 Liu et al., 2020). These data indicate that glucose is essential for the growth of S. Our previous study has revealed that fermentation of glucose contributes to aggregation of S. aureus, which favors the fermentation of glucose over other carbohydrates ( Vitko et al., 2016). In the skin and soft-tissue infections model, glucose transporters contribute to the growth of S. aureus under anaerobic conditions and high nitric oxide stress ( Richardson et al., 2008 Vitko et al., 2015). Glucose serves as an important carbohydrate for the growth of Staphylococcus aureus. aureus under high glucose conditions is due to impairment of the unique cell-wall structure, pentaglycine bridges. aureus, the growth of Staphylococcus haemolyticus and Staphylococcus epidermidis was also significantly decreased by an excess of glucose, but strains of Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa were unaffected by glucose. mRNA expression of genes encoding pentaglycine bridges, the substrate of lysostaphin, was significantly decreased in S. aureus from the culture medium with glucose had a thinner cell wall and highly resistant to lysostaphin compared with the bacteria cultured in LB medium. aureus was unaffected by these acidic conditions. Amounts of acid metabolites were produced under high glucose conditions, but the survival of planktonic S. aureus was also markedly decreased by fructose or sucrose. Except for glucose, the growth of planktonic S. aureus was significantly decreased in the Luria-Bertani (LB) medium supplemented with 25 mM glucose, and the reduced growth of S. The reduced eDNA content was not caused by degradation, because the nuclease activity of biofilm supernatants with glucose was significantly decreased due to the acidic pH of the medium. However, extracellular DNA (eDNA), an important component of biofilms, was markedly decreased in presence of 15 mM glucose. aureus grew in medium usually forms weak biofilm, and which was significantly increased by addition of glucose. Staphylococcus aureus is the most frequent pathogen isolated from diabetic foot ulcers, but the properties of this bacterium under high glucose conditions remain unclear. The high-glucose-induced cytotoxicity in diabetes has been widely recognized. 2Department of Laboratory Medicine, Hunan Normal University School of Medicine, Changsha, China.1Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China.Zhen Luo 1, Shan Yue 2, Ti Chen 1, Pengfei She 1, Yuan Wu 1* and Yong Wu 1* ![]()
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