Pseudomonas aeruginosa:pathogenesis,virulence factors,antibiotic resistance,interaction with host,technology advances and emerging therapeutics

Pseudomonas aeruginosa(P.aeruginosa)is a Gram-negative opportunistic pathogen that infects patients with cystic fibrosis,burn wounds,immunodeficiency,chronic obstructive pulmonary disorder(COPD),cancer,and severe infection requiring ventilation,such as COVID-19.P.aeruginosa is also a widely-used model bacterium for all biological areas.In addition to continued,intense efforts in understanding bacterial pathogenesis of P.aeruginosa including virulence factors(LPS,quorum sensing,two-component systems,6 type secretion systems,outer membrane vesicles(OMVs),CRISPR-Cas and their regulation),rapid progress has been made in further studying host-pathogen interaction,particularly host immune networks involving autophagy,inflammasome,noncoding RNAs,cGAS,etc.Furthermore,numerous technologic advances,such as bioinformatics,metabolomics,scRNA-seq,nanoparticles,drug screening,and phage therapy,have been used to improve our understanding of P.aeruginosa pathogenesis and host defense.Nevertheless,much remains to be uncovered about interactions between P.aeruginosa and host immune responses,including mechanisms of drug resistance by known or unannotated bacterial virulence factors as well as mammalian cell signaling pathways.The widespread use of antibiotics and the slow development of effective antimicrobials present daunting challenges and necessitate new theoretical and practical platforms to screen and develop mechanism-tested novel drugs to treat intractable infections,especially those caused by multi-drug resistance strains.Benefited from has advancing in research tools and technology,dissecting this pathogen’s feature has entered into molecular and mechanistic details as well as dynamic and holistic views.Herein,we comprehensively review the progress and discuss the current status of P.aeruginosa biophysical traits,behaviors,virulence factors,invasive regulators,and host defense patterns against its infection,which point out new directions for future investigation and add to the design of novel and/or alternative therapeutics to combat this clinically significant pathogen.

Paleo-Environment Reconstruction of the Middle Permian Lucaogou Formation,Southeastern Junggar Basin,NW China:Implications for the Mechanism of Organic Matter Enrichment in Ancient Lake

The Middle Permian Lucaogou Formation is the source rock and the main oil shale producing formation in the southeastern Junggar Basin.This study focused on the Lucaogou Formation exposed in two outcrop sections on the northern flank of the Bogda Mountain,namely the Jingjingzigou and Dalongkou sections.Here,we present integrated analysis of the sedimentology,major and trace elements,mineral components and total organic carbon contents.The paleo-environment was reconstructed including provenance,redox conditions,paleo-salinity,chemical weathering intensity and primary organic matter productivity.The results showed that the upper and lower units were deposited in distinct depositional environments with different organic matter accumulation mechanisms.The lower unit was characterized by low lake level,dry climate,fresh-brackish and well-oxygenated water.While during the deposition of the upper unit the lake level rose,climate turned wetter and the bottom water became less oxidized and much saltier.The mechanism of the organic matter accumulation is different for these two units.The preserved organic matters were mainly controlled by the primary productivity in the lower unit and by the redox conditions in the upper unit.