1.Effect of Different Fermentation Conditions on Fungal Community and Chemical Composition of Aurantii Fructus
Zhihong YAN ; Xiumei LIU ; Qiuyan GUAN ; Yonggui SONG ; Zhifu AI ; Genhua ZHU ; Yuhui PING ; Ming YANG ; Qin ZHENG ; Huanhua XU ; Dan SU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(11):254-262
ObjectiveTo investigate the effects of different fermentation methods and times on the fungal flora and chemical composition of Aurantii Fructus, in order to obtain the optimal fermentation conditions and flora structure, and to ensure the stability and controllability of the fermented varieties. MethodsScanning electron microscopy was used to observe and analyze the colony characteristics on the surface of Aurantii Fructus under different fermentation conditions. Internal transcribed spacer 2(ITS2) high-throughput sequencing, combined with fungal community diversity analysis and fungal community structure analysis, were used to obtain the fungal flora microbial categories of Aurantii Fructus under the conditions of traditional pressure-shelf fermentation and non-pressure-shelf natural fermentation for 7, 14, 21 d(numbered Y1-Y3 for the former, and numbered F1-F3 for the latter), respectively. At the same time, the chemical components in the fermentation process were detected by ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry(UPLC-Q-TOF-MS/MS), combined with principal component analysis(PCA), partial least squares-discriminant analysis(PLS-DA) and compound retention time, parent ions, characteristic fragment ions and other information, the differential compounds between the different fermentation samples were screened and identified. ResultsThe analysis of fungal community diversity showed that the dominant flora did not change at different fermentation time points in the traditional pressure-shelf fermentation method, while in the non-pressure-shelf natural fermentation method, there was a significant difference with the fermentation process, and at the genus level, the dominant genus of samples Y1, Y2, Y3 and F2 was Aspergillus, while the dominant genera of samples F1 and F3 were both Rhizopus. This indicated that the microbial growth environment provided by the traditional fermentation method was more stable, and the microbial community structure was more stable, which was more conducive to the stable and controllable fermentation process and fermented products. A total of 155 compounds were identified by compositional analysis, including 70 flavonoids, 38 coumarins, 10 alkaloids, 34 organic acids and 3 other compounds. After fermentation, two new components of ribalinine and pranferin were produced. Different fermentation conditions also brought about differences in chemical composition, multivariate statistical analysis obtained 26 differential compounds under two different fermentation methods, mainly including flavonoids, organic acids and coumarins. Comprehensively, the microbial community structure of samples fermented by the traditional pressure-shelf method of Aurantii Fructus for 14 d was stable, the species richness was high and the overall content of differential compounds was high, which was the optimal processing condition. ConclusionCompared with non-pressure-shelf natural fermentation, the traditional method has obvious advantages in terms of the stability of the microbial community structure and the content of chemical compounds, and the optimal condition is 14 days of fermentation. This study is helpful to promote the quality stability and fermentation bioavailability of fermented products of Aurantii Fructus, as well as to provide an experimental basis for the further improvement of the quality control methods of this variety.
2.Effect of Different Fermentation Conditions on Fungal Community and Chemical Composition of Aurantii Fructus
Zhihong YAN ; Xiumei LIU ; Qiuyan GUAN ; Yonggui SONG ; Zhifu AI ; Genhua ZHU ; Yuhui PING ; Ming YANG ; Qin ZHENG ; Huanhua XU ; Dan SU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(11):254-262
ObjectiveTo investigate the effects of different fermentation methods and times on the fungal flora and chemical composition of Aurantii Fructus, in order to obtain the optimal fermentation conditions and flora structure, and to ensure the stability and controllability of the fermented varieties. MethodsScanning electron microscopy was used to observe and analyze the colony characteristics on the surface of Aurantii Fructus under different fermentation conditions. Internal transcribed spacer 2(ITS2) high-throughput sequencing, combined with fungal community diversity analysis and fungal community structure analysis, were used to obtain the fungal flora microbial categories of Aurantii Fructus under the conditions of traditional pressure-shelf fermentation and non-pressure-shelf natural fermentation for 7, 14, 21 d(numbered Y1-Y3 for the former, and numbered F1-F3 for the latter), respectively. At the same time, the chemical components in the fermentation process were detected by ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry(UPLC-Q-TOF-MS/MS), combined with principal component analysis(PCA), partial least squares-discriminant analysis(PLS-DA) and compound retention time, parent ions, characteristic fragment ions and other information, the differential compounds between the different fermentation samples were screened and identified. ResultsThe analysis of fungal community diversity showed that the dominant flora did not change at different fermentation time points in the traditional pressure-shelf fermentation method, while in the non-pressure-shelf natural fermentation method, there was a significant difference with the fermentation process, and at the genus level, the dominant genus of samples Y1, Y2, Y3 and F2 was Aspergillus, while the dominant genera of samples F1 and F3 were both Rhizopus. This indicated that the microbial growth environment provided by the traditional fermentation method was more stable, and the microbial community structure was more stable, which was more conducive to the stable and controllable fermentation process and fermented products. A total of 155 compounds were identified by compositional analysis, including 70 flavonoids, 38 coumarins, 10 alkaloids, 34 organic acids and 3 other compounds. After fermentation, two new components of ribalinine and pranferin were produced. Different fermentation conditions also brought about differences in chemical composition, multivariate statistical analysis obtained 26 differential compounds under two different fermentation methods, mainly including flavonoids, organic acids and coumarins. Comprehensively, the microbial community structure of samples fermented by the traditional pressure-shelf method of Aurantii Fructus for 14 d was stable, the species richness was high and the overall content of differential compounds was high, which was the optimal processing condition. ConclusionCompared with non-pressure-shelf natural fermentation, the traditional method has obvious advantages in terms of the stability of the microbial community structure and the content of chemical compounds, and the optimal condition is 14 days of fermentation. This study is helpful to promote the quality stability and fermentation bioavailability of fermented products of Aurantii Fructus, as well as to provide an experimental basis for the further improvement of the quality control methods of this variety.
3.Exploring Regulatory Effect of Kaixuan Jiedu Core Prescription on SPHK2/S1P/MCP-1 Pathway in Psoriasis-like Mouse Model Based on Sphingolipid Metabolism
Yeping QIN ; Wenhui LIU ; Dan DAI ; Jia XU ; Chong LI ; Bin YANG ; Ping SONG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(17):60-68
ObjectiveTo explore the effects of Kaixuan Jiedu core prescription (KXJD) on sphingolipid metabolism in the mouse model of imiquimod-induced psoriasis-like skin lesions. MethodsThirty-seven male C57BL/6J mice were randomly assigned into five groups: healthy control (n=11), model (n=11), methotrexate (MTX, n=5), low-dose (15.21 g·kg-1) KXJD (n=5), and high-dose (30.42 g·kg-1) KXJD (n=5). Psoriasis-like skin lesions were induced in mice with 62.5 mg 5% imiquimod cream applied on the back. The KXJD groups and MTX group were treated with 0.2 mL corresponding decoction and MTX, respectively, by gavage daily, while the other groups were given an equal volume of normal saline by the same way. After 5 days of treatment, back skin lesions were collected. Firstly, healthy control and model mice were selected for tandem mass tag (TMT) quantitative proteomics (control vs model=3 vs 3) and targeted lipid metabolomics (control vs model=11 vs 11). Then, the binding degree between core components and target proteins was predicted via network pharmacology and molecular docking. Finally, an animal experiment was performed to decipher the specific regulation mechanism of KXJD on sphingolipid metabolism. Immunohistochemistry was employed to determine the expression level of sphingosine-1-phosphate (S1P), and Western blot was employed to determine the expression levels of sphingosine kinase 2 (SPHK2) and monocyte chemotactic protein-1 (MCP-1). ResultsTMT proteomics and targeted lipid metabolomics suggested that sphingolipid metabolism was active in the psoriatic skin, and key proteases [serine palmitoyltransferase, long chain base subunit 2 (SPTLC2), SPHK2, delta(4)-desaturase sphingolipid 1 (Degs1), and ceramide synthase 4 (CerS4)] and 8 sphingolipid metabolites (including ceramides, sphingol, sphingomyelin, and glycosphingolipid) expressed abnormally (P<0.05) compared with those in the healthy skin. The molecular docking results indicated that the binding energy between the active components (quercetin, kaempferol, and luteolin) in KXJD and key proteins involved in sphingolipid metabolism was less than-8 kal·mol-1. Further experimental verification showed elevated expression levels of SPHK2, S1P, and MCP-1 in psoriatic skin compared with healthy skin (P<0.05), and KXJD down-regulated the expression levels of SPHK2, S1P, and MCP-1 compared with the model group (P<0.05). ConclusionThis study indicates that there is an imbalance in sphingolipid metabolism in psoriatic skin lesions. KXJD may reduce psoriasis-like lesions in mice by regulating sphingolipid metabolism via the SPHK2/S1P/MCP-1 pathway.
4.Exploring Regulatory Effect of Kaixuan Jiedu Core Prescription on SPHK2/S1P/MCP-1 Pathway in Psoriasis-like Mouse Model Based on Sphingolipid Metabolism
Yeping QIN ; Wenhui LIU ; Dan DAI ; Jia XU ; Chong LI ; Bin YANG ; Ping SONG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(17):60-68
ObjectiveTo explore the effects of Kaixuan Jiedu core prescription (KXJD) on sphingolipid metabolism in the mouse model of imiquimod-induced psoriasis-like skin lesions. MethodsThirty-seven male C57BL/6J mice were randomly assigned into five groups: healthy control (n=11), model (n=11), methotrexate (MTX, n=5), low-dose (15.21 g·kg-1) KXJD (n=5), and high-dose (30.42 g·kg-1) KXJD (n=5). Psoriasis-like skin lesions were induced in mice with 62.5 mg 5% imiquimod cream applied on the back. The KXJD groups and MTX group were treated with 0.2 mL corresponding decoction and MTX, respectively, by gavage daily, while the other groups were given an equal volume of normal saline by the same way. After 5 days of treatment, back skin lesions were collected. Firstly, healthy control and model mice were selected for tandem mass tag (TMT) quantitative proteomics (control vs model=3 vs 3) and targeted lipid metabolomics (control vs model=11 vs 11). Then, the binding degree between core components and target proteins was predicted via network pharmacology and molecular docking. Finally, an animal experiment was performed to decipher the specific regulation mechanism of KXJD on sphingolipid metabolism. Immunohistochemistry was employed to determine the expression level of sphingosine-1-phosphate (S1P), and Western blot was employed to determine the expression levels of sphingosine kinase 2 (SPHK2) and monocyte chemotactic protein-1 (MCP-1). ResultsTMT proteomics and targeted lipid metabolomics suggested that sphingolipid metabolism was active in the psoriatic skin, and key proteases [serine palmitoyltransferase, long chain base subunit 2 (SPTLC2), SPHK2, delta(4)-desaturase sphingolipid 1 (Degs1), and ceramide synthase 4 (CerS4)] and 8 sphingolipid metabolites (including ceramides, sphingol, sphingomyelin, and glycosphingolipid) expressed abnormally (P<0.05) compared with those in the healthy skin. The molecular docking results indicated that the binding energy between the active components (quercetin, kaempferol, and luteolin) in KXJD and key proteins involved in sphingolipid metabolism was less than-8 kal·mol-1. Further experimental verification showed elevated expression levels of SPHK2, S1P, and MCP-1 in psoriatic skin compared with healthy skin (P<0.05), and KXJD down-regulated the expression levels of SPHK2, S1P, and MCP-1 compared with the model group (P<0.05). ConclusionThis study indicates that there is an imbalance in sphingolipid metabolism in psoriatic skin lesions. KXJD may reduce psoriasis-like lesions in mice by regulating sphingolipid metabolism via the SPHK2/S1P/MCP-1 pathway.
5.Construction and validation of a risk predictive model for the bowel preparation failure in colonoscopy patients
Ya LIU ; Xiaoqing LIU ; Xuening YANG ; Ping WANG ; Xuekui LIU ; Dan LUO
Chinese Journal of Nursing 2024;59(9):1091-1098
Objective To analyze the predictive value of fecal form for the quality of bowel preparation in patients scheduled for colonoscopy,identify risk factors for bowel preparation failure,and develop and validate a risk prediction model.Methods This was a prospective cohort study using convenience sampling.Patients scheduled for colonoscopy in the Digestive Department of a tertiary A hospital in Jiangsu Province from June to December 2022 were included in the modeling cohort.General information sheet and the Bristol Stool Form Scale(BSFS)were used for data collection.Patients were categorized into a successful bowel preparation group and a bowel preparation failure group based on the quality of bowel preparation.The optimal cutoff value for BSFS was determined using the best cutoff value method.Logistic regression analysis was employed to identify risk factors for bowel preparation failure,and a nomogram risk prediction model was constructed.Patients undergoing colonoscopy in the same hospital from January to February 2023 were served as the validation cohort.Results The modeling cohort included 569 patients,and the validation cohort included 212 patients,with bowel preparation failure rates of 19.0%and 19.8%,respectively.The risk prediction model formula derived from logistic regression analysis was P=-2.209+0.619 × hospitalized patients+0.635 × age≥65 years-0.710 × previous colonoscopy history+2.031 × BSFS type 1~2.The area under the receiver operating characteristic curve for the model was 0.751,with a sensitivity of 54.6%,a specificity of 85.9%,and the optimal cutoff value was 0.225,corresponding to a risk score of 80 for bowel preparation failure.The Hosmer-Lemeshow test showed x2=4.429,P=0.351.External validation demonstrated an area under the receiver operating characteristic curve of 0.775,indicating good model fit and high predictive value.Conclusion The incidence of bowel preparation failure in colonoscopy patients is relatively high.Patients aged 65 years,hospitalized patients,those with no history of colonoscopy,and those with BSFS type 1~2 are more likely to experience bowel preparation failure.The risk prediction model developed in this study has good predictive performance and can provide a basis for clinical nurses to quickly assess the risk of bowel preparation failure in patients.
6.National bloodstream infection bacterial resistance surveillance report(2022): Gram-positive bacteria
Chaoqun YING ; Yunbo CHEN ; Jinru JI ; Zhiying LIU ; Qing YANG ; Haishen KONG ; Haifeng MAO ; Hui DING ; Pengpeng TIAN ; Jiangqin SONG ; Yongyun LIU ; Jiliang WANG ; Yan JIN ; Yuanyuan DAI ; Yizheng ZHOU ; Yan GENG ; Fenghong CHEN ; Lu WANG ; Yanyan LI ; Dan LIU ; Peng ZHANG ; Junmin CAO ; Xiaoyan LI ; Dijing SONG ; Xinhua QIANG ; Yanhong LI ; Qiuying ZHANG ; Guolin LIAO ; Ying HUANG ; Baohua ZHANG ; Liang GUO ; Aiyun LI ; Haiquan KANG ; Donghong HUANG ; Sijin MAN ; Zhuo LI ; Youdong YIN ; Kunpeng LIANG ; Haixin DONG ; Donghua LIU ; Hongyun XU ; Yinqiao DONG ; Rong XU ; Lin ZHENG ; Shuyan HU ; Jian LI ; Qiang LIU ; Liang LUAN ; Jilu SHEN ; Lixia ZHANG ; Bo QUAN ; Xiaoping YAN ; Xiaoyan QI ; Dengyan QIAO ; Weiping LIU ; Xiusan XIA ; Ling MENG ; Jinhua LIANG ; Ping SHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2024;17(2):99-112
Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System(BRICS)were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute(CLSI). WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units,and the top five bacteria were Staphylococcus aureus( n=1 147,36.3%),coagulase-negative Staphylococci( n=928,29.3%), Enterococcus faecalis( n=369,11.7%), Enterococcus faecium( n=296,9.4%)and alpha-hemolyticus Streptococci( n=192,6.1%). The detection rates of methicillin-resistant Staphylococcus aureus(MRSA)and methicillin-resistant coagulase-negative Staphylococci(MRCNS)were 26.4%(303/1 147)and 66.7%(619/928),respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome,rifampin,compound sulfamethoxazole,linezolid,minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%(2/369),and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions( χ2=14.578, P=0.002),while the detection rate of MRCNS in northern China was significantly higher than that in other regions( χ2=15.195, P=0.002). The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals( χ2=13.519 and 12.136, P<0.001). The detection rates of MRSA and MRCNS in economically more advanced regions(per capita GDP≥92 059 Yuan in 2022)were higher than those in economically less advanced regions(per capita GDP<92 059 Yuan)( χ2=9.969 and 7.606, P=0.002和0.006). Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China, Staphylococci is the most common while the MRSA incidence decreases continuously with time;the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China,with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.
7.Preoperative MRI parameters for prediction of early urinary continence after laparoscopic radical prostatectomy
Di GUAN ; Wen-Jing XIANG ; Yue-Xin LIU ; Dan LIU ; Yi-Qun GU ; Hao PING
National Journal of Andrology 2024;30(8):709-716
Objective:To explore the correlation of early urinary continence(UC)after laparoscopic radical prostatectomy(LRP)with relevant preoperative MRI parameters of the urinary tract structure and provide some theoretical evidence for screening the high-risk population with postoperative urinary incontinence.Methods:This study included 49 PCa patients aged 50-78 years trea-ted by LRP in Beijing Tongren Hospital from January 2015 to February 2021,and all followed up for 12 months.We collected the com-plete baseline data on the patients,the clinical data possibly related to early postoperative UC,the MRI anatomical parameters associat-ed with UC,and the data on the recovery of early postoperative UC.We recorded the number of urinary pads used,submitted the data obtained to SPSS 23.0 statistical analysis,and identified the possible relevant factors by univariate correlation analysis,followed by R40.3 or SPSS 23.0 multivariate logistic regression analysis of the included factors and the results of UC.Results:MRI images mani-fested that the prostate anteroposterior diameter averaged(4.0±1.11)cm,the transverse diameter(4.6±0.83)cm,the cephalo-caudal diameter 2.4-6.4 cm,the membranous urethral length(MUL)(13.16±3.52)mm,and the thickness of the urethral rhab-dosphincter(URS)1.08-4.37 mm.Multivariate analysis showed that age was significantly correlated with the recovery of UC at 1 month after LRP(P=0.035,OR=0.16),and so was the URS thickness at 3 months(P=0.011,OR=0.02),9 months(P=0.014,OR=0.039)and 12 months(P=0.014,OR=0.039).Urinary incontinence with the URS thickness ≤1.6 mm at 12 months after operation was found of a high severity(P=0.010,OR[95%CI]=0.858-6.240).The MUL was positively correla-ted with the recovery of UC at 9 months(P=0.024,OR=0.508)and 12 months(P=0.024,OR=0.508)postoperatively.Correlation analysis revealed that the prostate volume,prostate diameter and other factors included in this study were not significantly correlated to postoperative UC.Conclusion:The thickness of the URS is positively correlated with the recovery of early UC,the thinner the URS,the severer the UC,and so is MUL.Age is an independent risk factor for the recovery of UC at 1 month after LRP.These findings need to be further verified by more prospective studies with long-term follow-ups.
8.Gene expression characteristics of lncRNAs and mRNAs in the sperm of asthenospermia patients
Shui-Bo SHI ; Long-Hua LUO ; Lian LIU ; Xue-Ming HUANG ; Su-Ping XIONG ; Dan-Dan SONG ; Dong-Shui LI
National Journal of Andrology 2024;30(9):782-788
Objective:To determine the differential expressions of long non-coding RNA(lncRNA)and messenger RNA(mRNA)in normal and asthenospermia(AS)men and analyze their biological significance in AS.Methods:We isolated and ex-tracted total RNAs from 9 normal and 9 AS sperm samples,determined the expressions of RNAs in the sperm using the DNBSEQ se-quencing platform,and analyzed their relevant functions by gene ontology enrichment(GO)and Kyoto encyclopedia of genes and ge-nomes pathway(KEGG)analyses.Results:An average of 10.64G data was generated per group,with 282 185 RNAs detected,in-cluding 107 009 lncRNAs.Among the total number of lncRNAs,15 157 were differentially expressed,2 190 upregulated and 12 967 downregulated;and among the 19 514 mRNAs,13 736 were differentially expressed,4 995 upregulated and 8 741 downregulated.Differentially expressed genes were enriched mainly in the sperm cell membrane and the pathways related to the ion channel functions,sperm development and fertilization.Conclusion:Differentially expressed lncRNAs and mRNAs can be identified by sequencing a-nalysis of AS and normal sperm.Regulation of sperm function through membrane ion channels may contribute to the development of AS,which provides a molecular basis for further research on AS.
9.Identification of prognostic genes in prostate cancer by single-cell sequencing combined with Mendelian randomization
Di GUAN ; Long-Long FU ; Yue-Xin LIU ; Dan LIU ; Yi-Qun GU ; Hao PING
National Journal of Andrology 2024;30(11):974-981
Objective:To identify the key genes involved in the development and progression of prostate cancer(PCa)and those associated with the prognosis of the malignancy.Methods:We obtained the single-cell sequencing data on 4 cases of PCa from the GSE156632 database.Using R language and the Seurat package,we performed cell clustering and annotation,selected the subpop-ulations of epithelial cells for differential analysis after quality control and cell type identification,and conducted enrichment analysis of the identified differential genes using the Hiplot website.Then we downloaded the single nucleotide polymorphism(SNP)loci corre-sponding to the expression quantitative trait loci(eQTL)of these genes from the UK Biobank(UKB)database,and the clinical data and corresponding gene expression data on PCa patients from The Cancer Genome Atlas(TCGA)and Gene Expression Omnibus(GEO),followed by univariate COX regression analysis of the impact of the genes on the prognosis of the patients after Mendelian ran-domization.Results:A total of 1 566 genes were identified and subjected to enrichment analysis,which indicated that the differenti-al genes might be enriched in the Ras,apoptosis and oxidative phosphorylation signaling pathways.Subsequent Mendelian randomiza-tion revealed 74 potential causal genes among the 1 566 genes,and univariate COX regression analysis of the 74 genes identified 4 pos-sibly related genes FAM3B,JUNB,TMEM59,and KRT5.Comparison of the results of Mendelian randomization and univariate COX regression showed that KRT5 might be the most important gene influencing PCa.Conclusion:FAM3B,JUNB,TMEM59 and KRT5 may play a role in the progression of PCa,and KRT5 may potentially serve as a prognostic predictor and therapeutic target for the malig-nancy.
10.Mechanism of carvacrol on inhibiting biofilm formation of hypervirulent Klebsiella pneumoniae
Chun-Ping WEI ; Tian-Xin XIANG ; Yang LIU ; Na CHENG ; Fei HAN ; Li ZHOU ; Peng LIU ; Dan-Dan WEI
Chinese Journal of Infection Control 2024;23(7):833-839
Objective To explore the potential mechanism of carvacrol on inhibiting the formation of biofilm of hy-pervirulent Klebsiella pneumoniae(hvKP).Methods The possible mechanisms of carvacrol were analyzed based on the detection of its effects on the formation and morphology of biofilms,changes in extracellular polysaccharide and capsule polysaccharide content,as well as changes in the expression levels of biofilm-related genes rmpA2,mag A,mrkA,mrkB,and treC of hvKP.Results The minimum inhibitory concentration of carvacrol on hvKP was 512 μg/mL,with an obvious inhibitory effect on the biofilm formation of hvKP,presenting a concentration-depen-dent effect.Under the scanning electron microscope,it was observed that the biofilm structure was loose and the in-tercellular connections were not dense under the intervention of carvacrol.The Congo Red adsorption test and m-hydroxybiphenyl colorimetric method showed that carvacrol could reduce the content of capsule polysaccharides of hvKP,but didn't affect the total extracellular polysaccharide content.Fluorescence quantitative polymerase chain reaction(PCR)showed that under the effect of carvacrol at sub-inhibitory concentration,the synthesis of capsule polysaccharide,expression levels of sugar transport system and pili adhesion-related genes all decreased by more than 50%.Conclusion Carvacrol has a significant inhibitory effect on the formation of biofilm in hvKP,and its mechanism may be related to the decrease of synthesis of capsule polysaccharide as well as expression of biofilm-re-lated genes,such as sugar transport system and pili adhesion.

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