1.Mechanism of horizontal transfer of linezolid resistance gene optrA media-ted by plasmids in Enterococcus faecalis
Peini YANG ; Li CHEN ; Wei HE ; Xiuwei ZHAI ; Mei LYU ; Qing WANG ; Xu YANG
Chinese Journal of Infection Control 2025;24(1):67-76
Objective To study the horizontal transfer mechanism of optrA gene-carrying linezolid-resistant En-terococcus faecalis(LREf)among clinical Enterococcus faecalis mediated by plasmids.Methods Non-repeated LREf from a tertiary first-class hospital in Kunming City from August 2022 to August 2023 were collected and iden-tified by matrix-assisted laser desorption/ionisation-time of flight mass spectrometry(MALDI-TOF MS).Antimi-crobial susceptibility testing was performed by VITEK 2 Compact,disc diffusion method and microbroth dilution method,optrA gene was detected by polymerase chain reaction(PCR),molecular biology characteristics of LREf was analyzed by whole-genome sequencing(WGS),LREf as the donor strain and clinically isolated Enterococcus faecalis as the recipient strain for conjugation test.Results A total of 17 LREf strains were collected,optrA gene was detected from plasmids of 12 LREf strains.Multiple resistance genes and virulence genes were detected.12 LREf strains were mainly ST16 type(50.0%).Among the 24 transconjugates in the conjugation test,8 were suc-cessfully conjugated,with a conjugation rate of 33.3%.Further analysis revealed that IS1216E insertion sequences presented at upstream and downstream of the optrA gene on the plasmid before and after conjugation of strains,and formed IS1216E-fexA-optrA-erm(A)-IS1216E-like transposon units.Conclusion The optrA gene can be horizon-tally transferred among clinical Enterococcus faecalis by mediating of plasmid of genes carrying both erm(A)and fexA,and the insertion sequence IS1216E plays an important role in its horizontal transfer process.
2.Mechanism of horizontal transfer of linezolid resistance gene optrA media-ted by plasmids in Enterococcus faecalis
Peini YANG ; Li CHEN ; Wei HE ; Xiuwei ZHAI ; Mei LYU ; Qing WANG ; Xu YANG
Chinese Journal of Infection Control 2025;24(1):67-76
Objective To study the horizontal transfer mechanism of optrA gene-carrying linezolid-resistant En-terococcus faecalis(LREf)among clinical Enterococcus faecalis mediated by plasmids.Methods Non-repeated LREf from a tertiary first-class hospital in Kunming City from August 2022 to August 2023 were collected and iden-tified by matrix-assisted laser desorption/ionisation-time of flight mass spectrometry(MALDI-TOF MS).Antimi-crobial susceptibility testing was performed by VITEK 2 Compact,disc diffusion method and microbroth dilution method,optrA gene was detected by polymerase chain reaction(PCR),molecular biology characteristics of LREf was analyzed by whole-genome sequencing(WGS),LREf as the donor strain and clinically isolated Enterococcus faecalis as the recipient strain for conjugation test.Results A total of 17 LREf strains were collected,optrA gene was detected from plasmids of 12 LREf strains.Multiple resistance genes and virulence genes were detected.12 LREf strains were mainly ST16 type(50.0%).Among the 24 transconjugates in the conjugation test,8 were suc-cessfully conjugated,with a conjugation rate of 33.3%.Further analysis revealed that IS1216E insertion sequences presented at upstream and downstream of the optrA gene on the plasmid before and after conjugation of strains,and formed IS1216E-fexA-optrA-erm(A)-IS1216E-like transposon units.Conclusion The optrA gene can be horizon-tally transferred among clinical Enterococcus faecalis by mediating of plasmid of genes carrying both erm(A)and fexA,and the insertion sequence IS1216E plays an important role in its horizontal transfer process.
3.Research progress of the roles of tumor-associated macrophages in gallbladder cancer
Ziheng YUAN ; Ying HU ; Xiuwei ZHAI
Tumor 2023;43(10):821-828
Gallbladder cancer(GBC)is a common malignancy of the biliary system with a poor diagnosis.The 5-year survival rate for patients with advanced GBC is less than 10%.Surgery is the only effective treatment for this disease.Tumor microenvironment(TME)plays an important role in GBC tumorigenesis,progression and prognosis.Tumor-associated macrophages(TAMs)are among the most abundant immune cells infiltrating the TME and are present in all stages of GBC progression.This paper has summarized the dynamic phenotypic transformation that macrophages undergo during GBC progression,discussed the impact that TAMs bring to GBC progression and the therapeutic potential of TAM-targeted strategies,and proposed the possible ways in which TAM are involved in the mechanism of GBC progression and are linked to the construction of the immunosuppressive TME.A generalization and analysis of the biological properties of TAM and their roles in GBC was carried out in the hope to provide reference for the development and innovation of GBC therapies.

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