yan du

 Carbapenem-resistant Enterobacteriaceae (CRE) has become a public health threat due to resistance to multiple antibiotics. The production of β-lactamase is the most important resistance mechanism of Enterobacteriaceae. Although isolates producing KPC-2 or NDM-1 enzymes have been reported widely, isolates co-producing KPC-2, NDM-1, TEM-1, TEM-95, SHV-66, and other β-lactamases have rarely been detected in the same strain, especially in Enterobacter cloacae.

 In this study, we identified and sequenced the genome of carbapenem-resistant E. cloacae ECL189 to in-depth analyze the resistance and transmission mechanisms of E. cloacae.

 We investigated the antimicrobial susceptibility of ECL189 by a VITEK 2 system, E-test gradient strips, and K-B method. Whole-genome sequencing was used by the PacBio RS II platform and Illumina HiSeq 4000 platform. Antimicrobial resistance genes, virulence genes, non-coding RNA, and repeat sequences were predicted by biological information databases. A PCR was used to further confirm that the blaKPC-2, blaNDM-1, blaTEM-1, blaTEM-95, and blaSHV-66 genes existed in ECL189. A conjugation experiment was performed to determine the transferability of resistance. Molecular typing of ECL189 was done by multilocus sequence typing (MLST).

 Enterobacter cloacae ECL189 was resistant to 21 out of 23 tested antibiotics, but its transconjugant was resistant to eight out of 18 tested antibiotics. The genome of ECL189 consisted of a 5,026,406 bp chromosome and four circular plasmids. In total, 26 resistance genes and 58 resistance proteins were identified. In addition, 77 determinants associated with bacterial virulence were identified. A large number of resistance and virulence genes were located in the plasmids. The results of whole-genome sequencing were consistent with the β-lactamase genes. The MLST analysis revealed that this strain belonged to ST74.

 This study further revealed the resistance, virulence, and transmission mechanisms of carbapenem-resistant E. cloacae. Resistance and virulence genes spread in bacteria by the horizontal transfer of plasmids, which should attract more attention in relevant departments.
 

Previously we reported functional leukocyte immunoglobulin-like receptor A3 (LILRA3) leads to susceptibility and sub-phenotypes of several autoimmune diseases. LILRA3 levels in blood serum and CD14+ monocytes enhanced in systemic lupus erythematosus and resulted in disease severity. However, the mechanism of LILRA3 in the pathogenesis of autoimmunity remains elusive. This study aims to explore the potential impact of LILRA3 on the differentiation, maturation, and function of monocyte-derived DCs (MoDCs). The human monocytic cell line (THP-1) was cultured to derive MoDCs in vitro. We performed plasmid transfection to examine the impact of LILRA3 on monocyte differentiation. Surface markers on MoDCs were measured using FACS. To assess the function of mature MoDCs, IL-12p70, IFN-γ and IL-4 levels were detected after the mixed leucocyte response by enzyme-linked immunosorbent assay. Western blot assay was employed in this study to determine the signaling pathways in MoDCs activation. LILRA3 promotes MoDCs maturation, our results showed significant up-regulation of CD40, CD80, CD86, CD209, and HLA-DR and increased production of pro-inflammatory cytokine IL-12. LILRA3-treated MoDCs exhibited a robust proliferation of allogeneic CD4+ T cells and induced naïve CD4+ T cell polarization into the Th1 phenotype. Furthermore, the preceding activation of MoDCs maturation and LILRA3 function might be attributed to p38 MAPK and STAT1 signaling pathway’s aberrant activation. This is the first study to report that LILRA3 played a critical role in promoting MoDCs maturation and directing MoDCs to modulate Th1 cell differentiation, which may have a role in the pathogenesis of autoimmune diseases.

COVID-19 is a public health emergency of international concern. Its incidence rates and mortality are very high; however, so far, an effective drug treatment remains unknown. Based on the role of convalescent plasma therapy in previously identified viral pneumonias, patients with severe COVID-19 have been given this therapy. This systematic review and meta-analysis aimed to summarize the clinical evidence regarding the efficacy and safety of convalescent plasma therapy in the treatment of severe COVID-19.

PubMed, Embase, Ovid, China Knowledge Network, China Biomedical, VIP Chinese Sci-tech Journal, Wanfang Database, and the International Clinical Trials Registry Platform were searched up to 21 June 2020, to identify clinical studies and registered trials on the use of convalescent plasma in the treatment of critically ill patients with COVID-19. Stata 13.0 was used to perform Meta-analysis. All records were screened as per the protocol eligibility criteria.

Nineteen clinical reports regarding convalescent plasma in the treatment of severe COVID-19 were included. Through systematic analysis, convalescent plasma was found to yield some efficacy on severe COVID-19 and had almost no obvious adverse reactions.

Convalescent plasma therapy seems to yield some efficacy among patients with severe COVID-19 and almost no obvious adverse reactions were found. However, at present, the clinical evidence is insufficient, and there is an urgent need for support from high-quality clinical trial data.

New Delhi metallo-beta-lactamase 1 (NDM-1) is considered to be an important factor of antimicrobial resistance in Enterobacteriaceae. In China, the blaNDM-1 gene has been mostly detected in carbapenem-resistant Acinetobacter spp. but is less reported in Enterobacteriaceae and more rarely found in E. cloacae.

This study explored the genetic features of the blaNDM-1 gene of E. cloacae and a blaNDM-1knockout mutant was constructed using Red homologous recombination. In addition, the effect of the knockout on antimicrobial resistance, growth ability, and in vitro competitiveness was investigated.

The upstream and downstream structures of the blaNDM-1 gene were analyzed in ten E. cloacae isolates using primer walking and PCR mapping. A blaNDM-1 knockout mutant was constructed through Red homologous recombination and verified by PCR, RT-qPCR, and sequencing. The antimicrobial susceptibility, growth curves, and in vitro growth competitiveness were compared between the blaNDM-1 knockout mutant and the parental strain.

All E. cloacae study isolates except for strain T10, contained an identical blaNDM-1 gene structure. The ΔISAba125 truncated by ISEc33 element and the bleo followed by a ΔtrpF and ISSen4 was located immediately upstream and downstream of T1-T9 strains. However, the ΔISAba125 and the bleo followed by a ΔtrpF were located immediately upstream and downstream, respectively, in the T10 strain. PCR, RT-qPCR, and DNA sequencing analyses showed that the blaNDM-1 knockout mutant was successfully constructed. The blaNDM-1 knockout mutant and the parental strain exhibited similar resistance patterns to penicillin, cephalosporins, aminoglycosides, tetracycline, and quinolones. Both strains displayed similar growth curves in Luria Broth. The competition index (CI), defined as the knockout mutant/parental strain ratio was 0.69 in the competition experiment in vitro.

The DNA regions upstream and downstream of the blaNDM-1 gene often contained insertion sequences and elements. Red homologous recombination was successfully used to knock out blaNDM-1 in E. cloacae, which allowed us to decipher the links between this gene, antimicrobial resistance, and bacterial growth competitiveness.

Context: Hepatocellular carcinoma (HCC) is a fatal disease. Chronic hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infection is the major cause of HCC. High viral replication rate and related hepatic/systematic inflammation are the major risk factors in HCC recurrence after hepatectomy or liver transplantation..Evidence Acquisition: Some of the carcinogenesis-related HBV mutations are also associated with poor prognosis for HCC patients. Antiviral therapy is an option for improving HCC prognosis after surgery. In case of HBV-associated HCC, treatment with interferon and nucleos(t)ide analogues (NAs), especially interferon, is effective in improving the prognosis. However, long-term use of NAs increases the possibility of developing drug-resistant viral mutations such as the HBV rtA181T/sW172 mutation, which increases the risk of HCC recurrence.. In cases of HCV-associated HCC, standard interferon with or without ribavirin therapy is effective in improving the prognosis of HCV-associated HCC; however, some HCV mutations, such as the amino acid substitution M91L, are associated with treatment failure and a poor prognosis. Therapeutic efficacy needs to be confirmed using largescale, randomized, placebo-controlled clinical trials.. Surveillance of viral mutations during antiviral treatment and a better understanding of the associations of HCC recurrence with viral load, inflammation-associated signaling, and environmental factors can aid the development of more effective strategies for the prevention of HCC recurrence after surgery.