Selection markers are essential tools in gene editing, the utility of such systems is inherently constrained by species-specific limitations, governed by divergent host genetic backgrounds and metabolic compatibility. To address this limitation, we leveraged the CRISPR/Cas9 system to develop a universal counter-selection tool. We designed and introduced an sgRNA expression cassettes as counter-selection markers, which directs the Cas9 protein to target and cleave genomic DNA, allowing for the selection of the strains where the sgRNA expression cassette has been replaced. Optimized to target multiple copy sites with sgRNA, this system significantly enhances cell lethality, boosting counter-selection efficiency to over 85.00%. This counter-selection tool is not limited to single strains and is suitable for various scenarios, including multi-copy plasmid assembly and plasmid editing, demonstrating broad application potential.
CRISPR-Cas Systems/genetics* ; Gene Editing/methods* ; RNA, Guide, CRISPR-Cas Systems/genetics* ; Plasmids/genetics*

Indanomycins are a class of secondary metabolites of microorganisms with a trans-tetrahydroindan (indane) ring. These compounds generally have good antibacterial, insecticidal and antitumor biological activities, which have caused wide interest for medicinal chemists and biologists. This review summarizes the research progress of the discovery, biological activity, chemical synthesis and biosynthesis of indanomycin compounds since 1979 and provides scientific reference for the research and development of indanomycin antibiotics.

Objective: To analyze the survival rate and its influencing factors of HIV/AIDS patients after antiviral therapy in Yinzhou District of Ningbo,so as to provide basis for AIDS prevention and control. Methods: The data of HIV/AIDS patients who received highly active antiretroviral therapy（HAART）in Yinzhou District from May 2005 to December 2014 were retrieved from the national AIDS comprehensive prevention and control information system;the survival rate was calculated by life table and Kaplan-Meier analysis;the influencing factors for survival time was analyzed by a multivariate cox proportional risk regression model. Results: Among 327 HIV/AIDS patients,twenty four were dead and three were lost. The average follow-up time was（5.63 ± 1.98）years. The cumulative survival rates of the subjects were 95%,92%,and 90% at 1,5,and 10 years after HAART. The Results of multivariate cox proportional risk regression analysis showed that patients who were at younger age when treatment begins（HR=1.053,95%CI: 1.001-1.108）,were transmitted by homosexual contact（HR=0.026,95%CI: 0.003-0.253）and by blood transmission（HR=0.043,95%CI: 0.006-0.309）,had high level of CD4+T lymphocyte at baseline（HR=0.993,95%CI: 0.988-0.998),and had viral load below the detection limit after six months of treatment（HR=0.028,95%CI: 0.009-0.084）were less likely to be dead. Conclusions The survival rate of HIV/AIDS patients after HAART is high,and is associated with the age when treatment begins,route of transmission,baseline CD4+T lymphocyte level and viral load after six months of treatment.

Objective To explore the variation and clinical significance of growth hormone(GH) and insulin like growth factor-Ⅰ(IGF-Ⅰ) in children with critical disease.Methods One hundred and twenty-two cases were recruited into the study,among which 42 cases were sepsis in paediatric intensive care unit (sepsis group),20 cases had finished the cardiopulmonary bypass surgery without infection (surgery group).Sixty healthy children served as control group.Serum levels of GH and IGF-Ⅰ were deteced with immunochemiluminometric assay.Results The serum levels of GH were (6.71 ± 6.62) ng/ml in sepsis group,(8.86 ±8.06) ng/ml in surgery group,(3.87 ± 3.31) ng/ml in control group.Compared with the control group,the serum levels of GH in sepsis group and surgery group were increased significantly (P ＜ 0.05).There was no significant difference between sepsis group and surgery group.The serum IGF-Ⅰ levels were (63.72 ±54.17) ng/ml in sepsis group,(119.06 ± 102.12) ng/ml in surgery group and(154.22 ± 107.10) ng/ml in control group separately.The serum IGF-Ⅰ level of sepsis group was significantly decreased compared to the other two groups (P ＜ 0.05).There was no significant difference between surgery group and control group (P ＞0.05).In sepsis group,compared with those who died,the GH of the survival showed no significant difference,IGF-Ⅰ was significantly increased.(P ＜ 0.05).Conclusion GH playes a positive effect in patients with critical disease.IGF-Ⅰ decreases greatly in patients with serious infection.It suggests that IGF-Ⅰ could be a sensitive marker for reflecting whether there is serious infection.The sharply decreasing of IGF-Ⅰ may predict a bad outcome.