Death caused by ST19 Klebsiella oxytoca with wcaG virulence gene in leukemic patient / 中国人兽共患病学报

We investigated the cause of a leukemia patient induced by infect in a strain of Klebsiella oxytoca with hypermucoviscosity (HMV) phenotype.Identification and drug susceptibility of the isolate were carried out with VITEK-2 compact system.HMV phenotype was detected by string-test.The major high virulence capsular serotypes (K1,K2,K5,K20,K54 and K57) and virulence factors (rmpA,wcaG,allS,kfu,aerobactin,fimH,uge,wabG and cf29a) were detected by polymerase chain reaction and DNA sequencing.Molecular typing was performed by multilocus sequence typing (MLST).Results showed that the isolates of blood and lung tissue were Klebsiella oxytoca belonged to ST 19,which were sensitive to the antibiotics used in test,expressing the HMV phenotype.The virulence gene wcaG was found,while other virulence genes and the major high virulence capsular serotypes were negative.It indicates that ST19 Klebsiella oxytoca with wcaG virulence gene is the main reason causing leukemic patient death.

The regulation mechanism of RIG-Ⅰ-like receptors in antiviral innate immune responses / 军事医学科学院院刊

Immune and tissue cells usually express pattern-recognition receptors (PRRs) to detect viruses and other microorganisms, thereby inducing signal cascade amplification and host innate immune responses. Since PRRs have strain-specific substrates and mechanisms of recognition, the identification of PRRs and mechanisms of PRRs-mediated responses is highly challenging. Besides, the research on RLRs-mediated immune responses has become more popular in cellular immunology recently. Accumulating evidence shows that post-translation modifications, such as ubiquitination, deubiquitination and ISGylation, play an important role in regulating host innate immune responses. In parallel, these approaches may be used by viruses to evade PRRs-mediated responses or to actively subvert these pathways for their own benefit. It was identified that STING (also called MITA/MPYS/ERIS) plays an important role in RIG-Ⅰ-like receptor(RLR) signaling as a type Ⅰ IFN stimulator, providing a special method for the research on complex host antiviral innate immune responses.