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Since the advent of penicillin, humans have known about and explored the phenomenon of bacterial inhibition via antibiotics. However, with changes in the global environment and the abuse of antibiotics, resistance mechanisms have been selected in bacteria, presenting huge threats and challenges to the global medical and health system. Thus, the study and development of new antimicrobials is of unprecedented urgency and difficulty. Bacteria surround themselves with a cell wall to maintain cell rigidity and protect against environmental insults. Humans have taken advantage of antibiotics to target the bacterial cell wall, yielding some of the most widely used antibiotics to date. The cell wall is essential for bacterial growth and virulence but is absent from humans, remaining a high-priority target for antibiotic screening throughout the antibiotic era. Here, we review the extensively studied targets, i.e., MurA, MurB, MurC, MurD, MurE, MurF, Alr, Ddl, MurI, MurG, lipid A, and BamA in the cell wall, starting from the very beginning to the latest developments to elucidate antimicrobial screening. Furthermore, recent advances, including MraY and MsbA in peptidoglycan and lipopolysaccharide, and tagO, LtaS, LspA, Lgt, Lnt, Tol-Pal, MntC, and OspA in teichoic acid and lipoprotein, have also been profoundly discussed. The review further highlights that the application of new methods such as macromolecular labeling, compound libraries construction, and structure-based drug design will inspire researchers to screen ideal antibiotics.

Yersinia pseudotuberculosis is a foodborne zoonotic bacterium that is pathogenic to guinea pigs, rabbits, and mice. It also causes pseudotuberculosis in humans. However, it still lacked the scientific basis for control. Here, we found out that Ebselen (EbSe) exhibited synergistic antibacterial activity with silver nitrate (Ag+) against Y. pseudotuberculosis YpIII strain with high efficacy in vitro using UV-visible light absorption spectrum, 5,5’-dithiobis-(2-nitrobenzoic acid), laser scanning confocal microscope, flow cytometry, transmission electron microscopy and Western blotting assays. The depletion of total glutathione (GSH) amount and inhibition of thioredoxin reductase (TrxR) activity in thiol-dependent redox system revealed the destructiveness of EbSe-Ag+-caused intracellular oxidative stress. Furthermore, a YpIII-caused mice gastroenteritis model was constructed. EbSe-Ag+ significantly reduced bacterial loads with low toxicity. It also down-regulated the expression levels of interferon (IL)-1β and tumor necrosis factor-α, up-regulated the expression level of IL-10 on-site. All the in vivo results demonstrated the antibacterial activity and immune-modulatory property of EbSe-Ag+. Collectively, these results provided academic fundament for further analysis and development of EbSe-Ag+ as the antibacterial agents for pseudotuberculosis control.

Aspergillosis of the central nervous system (CNS) is an uncommon infection, mainly found in immunocompromised patients but rarely seen among immunocompetent patients. Herein we describe a 57 year-old immunocompetent man who suffered intracranial aspergillosis spread by the pterygopalatine fossa (PPF) following a tooth extraction. Based on magnetic resonance imaging (MRI) characteristics, in this report we focus on the spreading routes of CNS aspergillosis via communicative structures of the PPF, the relationship between clinical manifestations and the locations of the lesion, and propose a therapeutic strategy to improve the prognosis. Keywords: Aspergillosis, Pterygopalatine fossa, Magnetic resonance imaging

Aspergillosis of the central nervous system (CNS) is an uncommon infection, mainly found in immunocompromised patients but rarely seen among immunocompetent patients. Herein we describe a 57 year-old immunocompetent man who suffered intracranial aspergillosis spread by the pterygopalatine fossa (PPF) following a tooth extraction. Based on magnetic resonance imaging (MRI) characteristics, in this report we focus on the spreading routes of CNS aspergillosis via communicative structures of the PPF, the relationship between clinical manifestations and the locations of the lesion, and propose a therapeutic strategy to improve the prognosis.