ObjectiveTo investigate microbial contamination status and distribution characteristics in laboratory animal barrier facilities, so as to provide a scientific basis for environmental quality control in barrier facilities. MethodsIn accordance with the national standard "Laboratory Animals—Environment and Housing Facilities" and the "Standard Operating Procedures" of the barrier facility, bacterial monitoring was performed on samples of air-settling bacteria, materials, and personnel gloves in the single-corridor barrier facility of the Animal Core Facility, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences (CEMCS). The monitoring data from January 2020 to December 2024 were collected, organized and statistically analyzed, and partial samples were subjected to species identification using PCR and sequencing methods. ResultsA total of 7 898 samples were collected from 2020 to 2024, including 3 175 air-settling bacteria samples, 3 353 material samples, and 1 370 glove samples. The overall compliance rate was 95.7% (7 559/7 898), among which the compliance rate of air-settling bacteria was 97.1% (3 084/3 175), that of materials was 93.2% (3 125/3 353), and that of personnel gloves was 98.5% (1 350/1 370). Over the five years, the compliance rates of all three types of monitored samples were above 90%. There were statistically significant differences in the compliance rates of air-settling bacteria and material samples among different quarters (P<0.05). Further investigation was conducted on samples collected from January to March 2024, and 190 bacterial strains were obtained through isolation and culture, including 126 strains from air-settling bacteria, 52 strains from materials, and 12 strains from personnel gloves. The strains were identified by PCR amplification and sequencing, and the 190 bacterial strains belonged to 9 genera and 20 species. Gram-positive bacteria accounted for the majority, with Staphylococcus as the dominant genus, accounting for 77.9% (148/190). ConclusionMicroorganisms carried by air, materials, and personnel gloves in barrier facilities are mainly Gram-positive bacteria. Regular monitoring of air-settling bacteria, materials, and personnel gloves in barrier facilities enables timely detection and control of potential risks during husbandry management and facility operation, which is of great significance for maintaining the sound operation of the barrier facility system and ensuring the quality of animal experiments.

ObjectiveTo investigate the effects of modified Buyang Huanwu Tang on cerebral ischemia-reperfusion injury （CI/RI） in mice via the PTEN-induced putative kinase 1/E3 ubiquitin ligase （PINK1/Parkin） signaling pathway-mediated mitophagy， and to explore the underlying mechanism by which modified Buyang Huanwu Tang improves CI/RI. MethodsSeventy-two male C57BL/6J mice were randomly divided into six groups （n = 12 per group）： Sham-operated group， middle cerebral artery occlusion/reperfusion （MCAO/R） model group， low-， medium-， and high-dose modified Buyang Huanwu Tang groups （8.84， 17.68， 35.36 g·kg^-1·d^-1）， and an aspirin group （13.00 mg·kg^-1·d^-1）. Neurological deficit scores were assessed using the Zea-Longa method. Cerebral infarct volume ratio was measured by 2，3，5-triphenyltetrazolium chloride （TTC） staining. Histopathological changes and neuronal injury in brain tissues were observed using hematoxylin-eosin （HE） staining and Nissl staining. Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling （TUNEL） assay. Mitochondrial ultrastructure in brain tissue was observed by transmission electron microscopy （TEM）. Serum levels of superoxide dismutase （SOD） and malondialdehyde （MDA） were determined by enzyme-linked immunosorbent assay （ELISA）. The mRNA and protein expression levels of PINK1， Parkin， microtubule-associated protein 1 light chain 3B （LC3B， LC3Ⅱ/Ⅰ）， and p62 in brain tissues were detected by real-time quantitative reverse transcription PCR （Real-time PCR） and Western blot， respectively. ResultsCompared with the sham-operated group， the MCAO/R model group showed significantly increased neurological deficit scores and cerebral infarct volume ratios （P<0.01）. Severe cortical injury on the infarct side was observed， characterized by decreased neuronal density， cytoplasmic vacuolation， nuclear pyknosis， a marked reduction in Nissl bodies， dissolution of Nissl bodies in the cytoplasm of some pyramidal neurons， and blurred cellular boundaries. The number of TUNEL-positive cells increased significantly （P<0.01）. Mitochondria exhibited cristae membrane rupture and matrix vacuolation， with rupture of the outer mitochondrial membrane and formation of autophagosomes， the number of which increased significantly. Serum SOD activity decreased significantly （P<0.01）， while MDA content increased significantly （P<0.01）. In infarcted brain tissues of model mice， the relative mRNA expression and protein levels of PINK1， Parkin and LC3B were significantly increased （P<0.05， P<0.01）， whereas p62 mRNA and protein expression were significantly decreased （P<0.05， P<0.01）， showing statistical significance. Compared with the model group， all treatment groups showed significantly decreased neurological deficit scores and cerebral infarct volume ratios （P<0.01）. Neuronal density increased significantly， cytoplasmic vacuolation was alleviated， nuclear morphology tended to be more regular and clearer， Nissl body density increased significantly with reduced dissolution and improved contour clarity. The mitochondrial cristae structure was partially restored， with some mitochondria showing autophagosome encapsulation， and the degree of mitochondrial damage was alleviated. Serum SOD activity increased significantly （P<0.01）， while MDA content decreased significantly. The mRNA and protein expression levels of PINK1， Parkin， and LC3Ⅱ/Ⅰ were significantly increased （P<0.05， P<0.01）， while p62 mRNA and protein expression in the low- and medium-dose modified Buyang Huanwu Tang groups were significantly decreased （P<0.05， P<0.01）， showing statistical significance. ConclusionModified Buyang Huanwu Tang can upregulate the protein expression levels of PINK1， Parkin， and LC3Ⅱ/Ⅰ and downregulate p62 protein expression， suggesting that it may improve CI/RI by regulating the expression of proteins related to the PINK1/Parkin signaling pathway. Regulation of the mitophagy pathway may be one of the mechanisms by which modified Buyang Huanwu Tang alleviates CI/RI in mice.

ObjectiveTo investigate the protective effect of α-ketoglutarate （α-KG） on hepatic lipid deposition in offspring caused by arsenic exposure during pregnancy. Methods8-week-old institute of cancer research （ICR） mice were mated in a ratio of 2∶1 between females and males， and the detection of vaginal plugs confirmed pregnant. A total of 32 pregnant mice were randomly divided into four groups： control group， arsenic group， α-KG group， arsenic+α-KG group. On gestational day 0-16 （GD0-GD16）， the arsenic and arsenic+α-KG groups were exposed to sodium arsenite （NaAsO₂ ，15 mg/L） in drinking water everyday， and the α-KG and arsenic+α-KG groups were gavaged with α-KG （2 g/kg） everyday. On GD16， pregnant mice were euthanized to collect fetal liver， and fetal body weight and crown-rump length were measured. Gene expression differences between the control group and the arsenic group were analyzed by transcriptome. The total triglycerides （TGs） and subtypes in fetal liver were detected by liquid chromatography tandem mass spectrometry （LC-MS/MS）. Oil red O staining was used to observe the histopathological changes in the liver. Quantitative polymerase chain reaction （qPCR） was used to detect the expression level of genes related to lipid synthesis， transport， and degradation， and phosphatidylinositol 3' -kinase/ protein kinase B （PI3K/AKT） in the liver of fetus. ResultsTranscriptomics analysis showed that 2 144 genes were downregulated and 1 675 genes were upregulated in the arsenic exposed fetal liver； body weight and crown-rump length were reduced （P_TuKey<0.05）； the level of hepatic TGs was elevated in arsenic group （P_TuKey<0.05）； oil-red O staining showed a significant increase in lipid droplets in arsenic group （P_TuKey<0.01）； the expression of lipid synthesis-related genes were significantly upregulated （P_TuKey<0.05）； the expression of β-oxidation-related genes and lipid degradation-related genes were downregulated （P_TuKey<0.05）； the expression of PI3K， AKT decreased（P_TuKey<0.05）. Compared with the arsenic group， the body weight and crown-rump length of fetus increased in the arsenic+α-KG group （P_TuKey<0.05）； the level of hepatic TGs decreased in the arsenic+α-KG group （P_TuKey<0.05）； oil red O staining showed lipid droplets significantly decreased （P_TuKey<0.01）； the expression of lipid synthesis-related genes were downregulated （P_TuKey<0.05）， the expression of β-oxidation-related genes and lipid degradation-related genes were upregulated （P_TuKey<0.05）； the expression levels of PI3K and AKT increased （P_TuKey<0.05）. Conclusionα-KG alleviated hepatic lipid deposition in offspring exposed to arsenic during pregnancy through activating PI3K/AKT signaling pathway.

OBJECTIVE To investigate the mechanism of Huangqin decoction in improving ulcerative colitis （UC） through the gut microbiota-tryptophan metabolism-aryl hydrocarbon receptor （AhR） axis. METHODS Mice were randomly divided into normal group （normal saline）， model group （normal saline）， microbiota depletion-model group （normal saline）， microbiota depletion-Huangqin decoction group （9.1 g/kg， by crude drug， similarly hereinafter）， Huangqin decoction group and mesalazine group （positive control group， 0.4 g/kg）， with 6 mice in each group. Microbiota depletion was achieved by providing free access to a mixed antibiotics for 10 days. The UC model was induced by administering 2.5% dextran sulfate sodium solution for 7 days. After successful modeling， each treatment group received corresponding drugs or normal saline intragastrically once daily for 10 days. After the final administration， body weight change ratio， disease activity index （DAI） score， and colon length were evaluated； colon pathological changes were observed； serum levels of interleukin-6 （IL-6）， IL-10， IL-22， and tumor necrosis factor-α （TNF-α） were measured； the expressions of Occludin， zonula occluden-1 （ZO-1）， and AhR in colon tissue were detected； fecal samples were subjected to high-throughput sequencing to analyze targeted tryptophan metabolomics. RESULTS Compared with the model group， Huangqin decoction group showed reduced infiltration of inflammatory cells in the colon tissue and restoration of the intestinal mucosal structure. Body weight change ratio， colon length， serum content of IL-10， the expressions of Occludin， ZO-1 and AhR in colon tissue and the contents of tryptophan metabolites indole-3-propionic acid （IPA）， N -acetylserotonin （NAS） and indole-3-acetic acid （IAA） were all significantly increased （ P ＜0.05）； DAI score， serum levels of IL-6， TNF-α， and IL-22 and the content of tryptophan metabolite indole-3-ethanol were significantly decreased （ P ＜0.05）； gut microbiota structure was improved， with increased relative abundances of beneficial bacteria such as Lactobacillus ， and decreased relative abundances of pathogenic bacteria such as Escherichia-Shigella . However， after antibiotic-induced microbiota depletion， although Huangqin decoction significantly increased the content of NAS in the feces of mice， the expression of AhR protein in colon tissue did not increase concurrently. CONCLUSIONS Huangqin decoction can repair the intestinal mucosal barrier in UC mice by regulating the gut microbiota and promoting the production of IPA and IAA， thereby activating AhR. This suggests that an intact gut microbiota is an important prerequisite for Huangqin decoction to exert its AhR-regulating effects.

Chronic liver diseases are a group of diseases in which the liver is subjected to a variety of injuries over a long period of time， resulting in irreversible pathological changes that last longer than 6 months. Emodin （EMO） is a natural anthraquinone derivative derived from Rheum officinale， and its pharmacological effect has been extensively studied， exhibiting a variety of biological properties and involving multiple signaling molecules and pathways. Western medicine or surgical treatment is currently the main treatment regimen for chronic liver diseases， and the advance in treatment is limited by various reasons such as side effects and high costs. Due to its natural origin and efficacy， EMO has unique advantages in the treatment of chronic liver diseases and has now become a research hotspot. This article summarizes the therapeutic effect of EMO on chronic liver diseases and its mechanism， in order to provide a certain scientific basis for the traditional Chinese medicine treatment of chronic liver diseases and the development of drugs in clinical practice.

ObjectiveTo explore the mechanism of Shaoyaotang in the prevention and treatment of colitis-associated carcinogenesis （CAC） based on myeloid-derived suppressor cells （MDSCs）-related immunosuppressive microenvironment. MethodsA total of 140 six-week-old SPF FVB male mice were randomly divided into seven groups： Blank group， Shaoyaotang without model group （7.12 g·kg^-1）， model group， sulfasalazine group （0.52 g·kg^-1）， Shaoyaotang low-dose group （3.56 g·kg^-1）， Shaoyaotang medium-dose group （7.12 g·kg^-1） and Shaoyaotang high-dose group （14.24 g·kg^-1）， with 20 mice in each group. The blank control group and the Shaoyaotang without model group received a single intraperitoneal injection of physiological saline （10 mg·kg^-1）， while the other five groups were given a single intraperitoneal injection of azoxymethane （AOM） （10 mg·kg^-1）. After 1 week， the mice were given drinking water containing 2% dextran sulfate sodium （DSS） for 1 week， followed by normal drinking water for 2 weeks. This cycle was repeated three times over a total period of 14 weeks to establish the CAC mouse model. Each group was administered gavage once daily for 2 weeks starting on the 14^th day of the experiment， followed by three times a week until the end of the experiment. The body weight of the mice was recorded weekly. Mice were sacrificed on the 28^th and 98^th days of the experiment. After dissection， the colon length， colon weight， spleen weight， tumor size， and tumor number were measured. Hematoxylin and eosin （HE） staining was used to assess the pathological morphology of colon tumor tissue. Flow cytometry was used to detect MDSCs， regulatory T cells （Tregs）， CD4⁺ T cells， CD8⁺ T cells， and the CD4⁺/CD8⁺ T cell ratio in the spleen. Immunohistochemistry was used to detect the expression levels of programmed cell death protein-1 （PD-1）， programmed cell death ligand 1 （PD-L1）， phosphorylated AMP-activated protein kinase （p-AMPK）， phosphorylated nuclear factor-κB （p-NF-κB）， and hypoxia-inducible factor 1α （HIF-1α） in the colon tissue. ResultsOn day 14， compared with the blank group， the body weight of the model group was significantly reduced （P<0.01）， reaching its lowest point on day 28 （23.39 ± 0.95 ） g. On days 28 and 98， compared with the blank group， the colon length in the model group was significantly shortened （P<0.01）， the colon index significantly increased （P<0.01）， the spleen index significantly increased （P<0.01）， and the tumor load significantly increased （P<0.01）. HE staining showed that in the model group， tumor cells， a large number of inflammatory cell infiltrates， goblet cell disappearance， and crypt loss were observed. In each dose group of Shaoyaotang， the damage to the colonic mucosa， inflammatory cell infiltration， and crypt structure destruction were alleviated. Compared with the model group， the body weight of mice in each dose group of Shaoyaotang increased. On day 98， the colon length was significantly increased （P<0.01）， the colon index significantly decreased （P<0.01）， the spleen index significantly decreased （P<0.01）， and the tumor burden significantly decreased （P<0.01） in each Shaoyaotang dose group. On days 28 and 98， MDSCs and Tregs in the spleen of the medium- and high-dose Shaoyaotang groups were significantly reduced （P<0.01）， while CD4⁺ T cells and the CD4⁺/CD8⁺ T cell ratio were significantly increased （P<0.01）. The proportion of CD8⁺ T cells in the spleen and the expression levels of PD-1 and PD-L1 in the colon tissues of mice in each Shaoyaotang dose group were significantly increased to varying degrees （P<0.05， P<0.01）. On days 28 and 98， the expression of p-AMPK-positive cells in the colon tissue of the medium- and high-dose Shaoyaotang groups was significantly increased （P<0.01）， while the expression of p-NF-κB and HIF-1α was significantly reduced （P<0.01）. ConclusionShaoyaotang can regulate MDSC recruitment and modulate the immune function of T lymphocyte subsets to inhibit the occurrence and development of AOM/DSS-induced CAC in mice. The mechanism may be related to the activation of the AMPK/NF-κB/HIF-1α pathway.

ObjectiveTo investigate the mechanism of topical treatment of allergic contact dermatitis （ACD） mice with Portulacae Herba based on the nuclear factor E₂-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1）/nuclear factor-κB （NF-κB） signaling pathway. MethodsA total of 70 6-week-old specific pathogen free （SPF） female Kunming mice were adaptively fed for 1 week and randomly divided into blank group， model group， compound dexamethasone acetate cream group （2.075×10^-2 g·g^-1）， blank matrix cream group， low-dose Portulacae Herba cream group （0.1 g·g^-1）， high-dose Portulacae Herba cream group （0.2 g·g^-1）， and Portulacae Herba + inhibitor group （0.2 g·g^-1 + 30 mg·kg^-1 ML385）， with 10 mice in each group. One day before the experiment， the mice were shaved on the neck and back. Except for the blank group， the mice in the other groups were treated with 2，4-dinitrochlorobenzene （DNCB） to establish an ACD model. After respective administration， the skin lesion of the mice was scored， and the histopathological changes of the skin were stained with hematoxylin-eosin （HE）. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of interleukin-6 （IL-6）， interleukin-1β （IL-1β）， reactive oxygen species （ROS）， superoxide dismutase （SOD） activity， and malondialdehyde （MDA） in serum of mice. The expression of Nrf2/HO-1/NF-κB signaling pathway-related proteins in mouse skin tissue was detected by immunohistochemistry （IHC）， Western blot， and real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultsCompared with the blank group， the mice in the model group had an increased skin lesion score （P<0.01）， severe pathological damage to skin tissue， increased content of IL-1β， IL-6， ROS， and MDA in their serum （P<0.01）， and decreased content of SOD （P<0.01）. In addition， the mRNA and protein expression levels of Nrf2， HO-1， and nuclear factor-κB inhibitor α （IκBα） in skin tissue were up-regulated （P<0.01）， while the protein expression levels of phosphorylated （p）-IκBα and p-NF-κB p65 and the mRNA expression of NF-κB p65 were down-regulated （P<0.01）. Compared with the model group and the blank matrix cream group， the mice treated with Portulacae Herba had a decreased skin lesion score （P<0.01）， reduced pathological damage to skin tissue， decreased content of IL-1β， IL-6， ROS， and MDA in their serum （P<0.01）， and increased content of SOD （P<0.01）. Additionally， the mRNA and protein expression levels of Nrf2， HO-1， and IκBα in skin tissue were down-regulated （P<0.05，P<0.01）， and the protein expression levels of p-IκBα and p-NF-κB p65 and the mRNA expression of NF-κB p65 were up-regulated （P<0.05，P<0.01）. Compared with the Portulacae Herba + inhibitor group， the high-dose Portulacae Herba cream group had a decreased skin lesion score （P<0.01）， alleviated pathological damage to skin tissue， decreased content of IL-1β， IL-6， ROS， and MDA in the serum of mice （P<0.05，P<0.01）， and increased content of SOD （P<0.01）. The protein expression levels of Nrf2， HO-1， and IκBα and the mRNA expression of Nrf2 and HO-1 in skin tissue were up-regulated （P<0.05，P<0.01）， and the protein expression levels of p-IκBα and p-NF-κB p65 and the mRNA expression of NF-κB p65 were down-regulated （P<0.05）. ConclusionPortulacae Herba can improve DNCB-induced ACD skin damage in mice by regulating the Nrf2/HO-1/NF-κB signaling pathway.

Object To study the efficacy and potential mechanism of Tongbianling capsule in constipation. Methods The effects of Tongbianling capsule on intestinal motility in normal mice and carbon powder propulsion rate in small intestine of constipation model mice after were observed administration. The potential targets and key pathways of Tongbianling capsule in treating constipation were identified through network pharmacology. To verify the mechanism, the expression of p-PI3K/PI3K, p-AKT/AKT and CASP3 proteins in mouse colon tissue was detected by the western blot. Results The time for mice to excrete the first black stool was shortened and the number of fecal particles was increased in Tongbianling capsule administration group, and the carbon powder propulsion rate of mice in each Tongbianling capsule administration group was increased. The results of network pharmacology showed that treatment of constipation by Tongbianling capsule may be related to signaling pathways such as PI3K-Akt signaling pathway and 5-HT. The protein expression of p-PI3K/PI3K, p-AKT/AKT, and CASP3 in mouse colon tissue could be significantly downregulated in administration group. Conclusion Tongbianling capsule could effectively promote intestinal peristalsis in mice, increase the frequency of defecation, and effectively treat constipation. The mechanism of its action may be related to the direct or indirect regulation of intestinal motility by the PI3K-Akt signaling pathway.

AIM:This study investigated the role of solute carrier family 7 member 11(SLC7A11)in sul-fasalazine(SAS)-induced ferroptosis in acute myeloid leukemia(AML)cells,focusing on the inhibitory effect of nuclear factor E2-related factor 2(NRF2)nuclear translocation-mediated activation of SLC7A11 on ferroptosis and its underlying mechanisms.METHODS:SAS-induced proliferation in AML cell lines,Kasumi-1 and THP-1,was assessed using the MTS assay.Cell death inhibitors were employed to determine the mode of cell death.Lipid reactive oxygen species(ROS)levels were measured by flow cytometry;Fe2+,malonodialdehyde(MDA),glutathione(GSH)levels,and glutathione per-oxidase 4(GPX4)activity were assessed using micromethods.Quantitative PCR(qPCR)was performed to evaluate changes in SLC7A11 mRNA during SAS-induced ferroptosis,while Western blot measured SLC7A11 and GPX4 protein levels.Moreover,Western blot assessed NRF2 nuclear translocation post-SAS treatment.The NRF2 inhibitor ML385 was used to validate these effects.SLC7A11 mRNA and protein levels were then measured following combined SAS and ML385 treatment via qPCR and Western blot.Cell viability and ferroptosis-related indices were evaluated under the same treatment conditions.Furthermore,a shRNA vector targeting SLC7A11 was constructed to assess changes in cell viability and ferroptosis markers after SLC7A11 knockdown with SAS.GPX4 protein levels were examined following SLC7A11 knockdown.RESULTS:SAS significantly inhibited the proliferation of Kasumi-1 and THP-1 cells at 200 μmol/L and 300 μmol/L,respectively(P<0.05).Only ferroptosis inhibitors(Fer-1 and DFO)significantly reversed SAS-induced cy-totoxicity(P<0.01).SAS increased lipid ROS,Fe2+,and MDA levels(P<0.01),while reducing GSH and GPX4 activity(P<0.01).The mRNA and protein expressions of SLC7A11 increased during SAS-induced ferroptosis(P<0.01),where-as GPX4 protein decreased significantly(P<0.01).SAS significantly increased the nuclear-to-cytoplasmic NRF2 ratio(P<0.01),which decreased upon co-treatment with ML385(P<0.05).Following SAS and ML385 co-treatment,both SLC7A11 mRNA and protein levels were downregulated(P<0.01).This combination treatment further reduced AML cell viability(P<0.01),an effect reversed by Fer-1 and DFO(P<0.01).Compared with SAS alone,the combination of SAS and ML385 significantly increased lipid ROS,Fe2+,and MDA while reducing GSH levels and GPX4 activity(P<0.01).SLC7A11 knockdown was successfully achieved.Compared with the NC shRNA group,SLC7A11 knockdown cells showed significantly decreased viability after SAS treatment,which was reversed by Fer-1 and DFO(P<0.01).Lipid ROS,Fe2+,and MDA content were significantly increased(P<0.01),and GSH and GPX4 were substantially decreased(P<0.05).Moreover,GPX4 protein expression was considerably reduced after SLC7A11 knockdown(P<0.01).CONCLUSION:SAS induces ferroptosis in AML cells.It promotes the nuclear translocation of NRF2 protein,which activates SLC7A11 ex-pression.Inhibition of NRF2 or downregulation of SLC7A11 sensitizes AML cells to SAS-induced ferroptosis.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.