1.Clinical application of an artificial intelligence system in predicting benign or malignant pulmonary nodules and pathological subtypes
Zhuowen YANG ; Zhizhong ZHENG ; Bin LI ; Yiming HUI ; Mingzhi LIN ; Jiying DANG ; Suiyang LI ; Chunjiao ZHANG ; Long YANG ; Liang SI ; Tieniu SONG ; Yuqi MENG
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2025;32(08):1086-1095
Objective To evaluate the predictive ability and clinical application value of artificial intelligence (AI) systems in the benign and malignant differentiation and pathological type of pulmonary nodules, and to summarize clinical application experience. Methods A retrospective analysis was conducted on the clinical data of patients with pulmonary nodules admitted to the Department of Thoracic Surgery, Second Hospital of Lanzhou University, from February 2016 to February 2025. Firstly, pulmonary nodules were divided into benign and non-benign groups, and the discriminative abilities of AI systems and clinicians were compared. Subsequently, lung nodules reported as precursor glandular lesions (PGL), microinvasive adenocarcinoma (MIA), and invasive adenocarcinoma (IAC) in postoperative pathological results were analyzed, comparing the efficacy of AI systems and clinicians in predicting the pathological type of pulmonary nodules. Results In the analysis of benign/non-benign pulmonary nodules, clinical data from a total of 638 patients with pulmonary nodules were included, of which there were 257 males (10 patients and 1 patient of double and triple primary lesions, respectively) and 381 females (18 patients and 1 patient of double and triple primary lesions, respectively), with a median age of 55.0 (47.0, 61.0) years. Different lesions in the same patient were analyzed as independent samples. Univariate analysis of the two groups of variables showed that, except for nodule location, the differences in the remaining variables were statistically significant (P<0.05). Multivariate logistic regression analysis showed that age, nodule type (subsolid pulmonary nodule), average density, spicule sign, and vascular convergence sign were independent influencing factors for non-benign pulmonary nodules, among which age, nodule type (subsolid pulmonary nodule), spicule sign, and vascular convergence sign were positively correlated with non-benign pulmonary nodules, while average density was negatively correlated with the occurrence of non-benign pulmonary nodules. The area under the receiver operating characteristic curve (AUC) of the malignancy risk value given by the AI system in predicting non-benign pulmonary nodules was 0.811, slightly lower than the 0.898 predicted by clinicians. In the PGL/MIA/IAC analysis, clinical data from a total of 411 patients with pulmonary nodules were included, of which there were 149 males (8 patients of double primary lesions) and 262 females (17 patients of double primary lesions), with a median age of 56.0 (50.0, 61.0) years. Different lesions in the same patient were analyzed as independent samples. Univariate analysis results showed that, except for gender, nodule location, and vascular convergence sign, the differences in the remaining variables among the three groups of PGL, MIA, and IAC patients were statistically significant (P<0.05). Multinomial multivariate logistic regression analysis showed that the differences between the parameters in the PGL group and the MIA group were not statistically significant (P>0.05), and the maximum diameter and average density of the nodules were statistically different between the PGL and IAC groups (P<0.05), and were positively correlated with the occurrence of IAC as independent risk factors. The average AUC value, accuracy, recall rate, and F1 score of the AI system in predicting lung nodule pathological type were 0.807, 74.3%, 73.2%, and 68.5%, respectively, all better than the clinical physicians’ prediction of lung nodule pathological type indicators (0.782, 70.9%, 66.2%, and 63.7% respectively). The AUC value of the AI system in predicting IAC was 0.853, and the sensitivity, specificity, and optimal cutoff value were 0.643, 0.943, and 50.0%, respectively. Conclusion This AI system has demonstrated high clinical value in predicting the benign and malignant nature and pathological type of lung nodules, especially in predicting lung nodule pathological type, its ability has surpassed that of clinical physicians. With the optimization of algorithms and the adequate integration of multimodal data, it can better assist clinical physicians in formulating individualized diagnostic and treatment plans for patients with lung nodules.
2.The effective connection of default mode network changes in patients with type 2 diabetes mellitus
Liying ZHANG ; Zhizhong SUN ; Limin GE ; Zidong CAO ; Weiye LU ; Wenbin QIU ; Yuna CHEN ; Shijun QIU
Chinese Journal of Diabetes 2024;32(2):91-96
Objective To investigate the influence of type 2 diabetes mellitus(T2DM)on cognitive function and the effective connectivity with in the default mode network(DMN)in the brain.Methods A total of 93 hospitalized patients diagnosed with T2DM were enrolled in this study as T2DM group from The First Affiliated Hospital of Guangzhou University of Chinese Medicine during September 2021 to December 2022.Simultaneously,108 healthy individuals were recruited from the community as normal control(NC)group.The cognitive functions were evaluated in the two groups.A random dynamic causal modeling approach was employed to analyze the effective connectivity within DMN in both groups.Additionally,Pearson correlation analysis was performed to examine the association between differential connectivity,clinical indicators,and cognitive scores in both groups.Results In comparison to the NC group,T2DM individuals exhibited statistically significant reductions in scores in the auditory verbal learning test(AVLT)for immediate recall and the digit symbol substitution test(DSST)(P<0.05).Additionally,they displayed a notable decrease in effective connectivity from the left lateral parietal cortex(LLPC)to the posterior cingulate cortex(PCC),as well as from the LLPC to the right lateral parietal cortex(RLPC)within the DMN(P<0.05).Pearson correlation analysis unveiled a negative association between HbA1c levels and the strength of effective connectivity from LLPC to PCC.Conversely,a positive correlation was observed between AVLT(immediate)scores and the strength of effective connectivity from LLPC to PCC and LLPC to RLPC.Additionally,DSST scores displayed a positive correlation with the strength of effective connectivity from LLPC to PCC(P<0.05).Conclusion Patients with T2DM display compromised effective connectivity from LLPC to PCC and LLPC to RLPC within the DMN network,and this alteration may associated with cognitive impairment.
3.Visualization method of mechanical power exposure intensity and duration in mechanical ventilation patients
Jingru ZHANG ; Zhizhong CHEN ; Shurong GONG ; Han CHEN
Chinese Critical Care Medicine 2024;36(7):705-711
Objective:To visualize the relationship between different combinations of mechanical power exposure intensity-duration and death risk in mechanical ventilation patients using a visualization method.Methods:Critically ill patients receiving mechanical ventilation were selected from the Medical Information Mart for Intensive Care-Ⅳ v1.0 (MIMIC-Ⅳ v1.0) database. The patients were divided into four subgroups according to oxygenation index (PaO 2/FiO 2) including > 300 mmHg (1 mmHg≈0.133 kPa) group, 201-300 mmHg group, 101-200 mmHg group and ≤100 mmHg group. The baseline characteristics, ventilator parameters, and prognostic indicators for different patient populations were collected. For each patient, the mechanical power thresholds from low to high (5-30 J/min, increasing at intervals of 1 J/min) were used to evaluate the different exposures of mechanical power (above the set threshold was recorded as one exposure), and the number of events with different exposure intensity-duration combinations was counted based on their corresponding durations. Based on the 28-day survival/non-survival status, the number of exposures for survivors and non-survivors in each exposure intensity-duration combination was calculated, and the survival odds ratio ( OR) for different mechanical power exposure intensity-duration combinations was subsequently computed. Two-dimensional tables were generated with mechanical power exposure duration on the x-axis and exposure intensity on the y-axis, and the heatmap and its corresponding equipotential line view were used to visualize the OR value to assess the risk of death. Results:A total of 5 378 patients receiving mechanical ventilation were enrolled in the study, of whom 2 069 patients in the PaO 2/FiO 2 > 300 mmHg group, 813 patients in the 201-300 mmHg group, 1 493 patients in the 101-200 mmHg group, and 1 003 patients in the ≤100 mmHg group. The severity scores of patients, including sequential organ failure assessment (SOFA) score and simplified acute physiology score Ⅱ (SAPSⅡ), gradually increased following the decrease in PaO 2/FiO 2, and the incidence of co-morbidities also gradually increased. In terms of ventilator parameters, mechanical power was increased gradually with decrease in PaO 2/FiO 2, measuring 10.4 (7.8, 13.9), 11.3 (8.5, 14.7), 13.6 (10.0, 18.2), and 16.7 (12.5, 22.0) J/min ( P < 0.01). In terms of prognosis, 28-day mortality of patients was gradually increased with decrease in PaO 2/FiO 2 [29.1% (601/2 069), 26.9% (219/813), 28.1% (420/1 493), and 33.3% (334/1 003), respectively, P < 0.05]. In the heatmap, it could be observed that the 28-day death risk of mechanical ventilation patients was gradually increased with increase in mechanical power exposure intensity and long duration, showing two distinct areas: a region near the bottom left corner (representing low mechanical power exposure intensity and short duration) was blue, indicating a greater chance of survival. In contrast, another region near the top right corner (representing high mechanical power exposure intensity and long duration) was red, indicating a higher risk of death. According to the fitted lines of death risk, for the same risk of death, a shorter mechanical power exposure duration was required for higher exposure intensity, while lower mechanical power exposure intensity required a longer exposure duration. The above trend of change was similarly reflected in the overall population and different oxygenation populations. Conclusions:Cumulative mechanical power exposure to higher intensity and/or longer duration is associated with worse outcomes in mechanical ventilation patients. Considering both the mechanical power exposure intensity and duration may help to evaluate the effectiveness of lung protection in mechanical ventilation patients and guide adjustments in mechanical ventilation strategy to reduce the risk of ventilator-induced lung injury.
4.A cross-sectional study of functional disability rate of anxiety disorder and risk factors in Chinese community adults
Yang LI ; Yueqin HUANG ; Zhaorui LIU ; Tingting ZHANG ; Chao MA ; Lingjiang LI ; Yifeng XU ; Tao LI ; Xiufeng XU ; Yaqin YU ; Yongping YAN ; Zhizhong WANG ; Xiangdong XU ; Limin WANG ; Qiang LI ; Guangming XU ; Shuiyuan XIAO
Chinese Mental Health Journal 2024;38(11):929-935
Objective:To describe functional disability rate of anxiety disorders in Chinese community adults and explore related risk factors of functional disability.Methods:To conduct in-depth data analysis on China Mental Health Survey(CMHS).The diagnostic tool for anxiety disorders was the Composite International Diagnostic Inter-view-3.0,according to the Diagnostic and Statistical Manual for Mental Disorders,Fourth Edition(DSM-Ⅳ).The World Health Organization Disability Assessment Schedule,2nd edition,was the functional disability assessment standard for anxiety disorders.Weighted 12-month functional disability rate of DSM-Ⅳ anxiety disorder with co-morbidities and only anxiety disorder in population and those in patients,as well as days of partial disability were calculated.The effects of anxiety disorders comorbid other mental disorders and physical diseases and demographic factors on the severity and occurrence of functional disability were analyzed by multiple linear regression and logis-tic regression.Results:The functional disability rate of anxiety disorder with comorbidities in population was 1.7%,and 42.2%in patients,in which constituent rate of grade-four disability was the highest as 84.1%.The functional disability rate of only anxiety disorder in population was 0.3%,and 17.8%in patients.The medians of days of partial disability days in the past 30 days were from 0 to 14.42.Multiple linear regression showed a positive association between comorbid anxiety disorder with other mental disorders and physical diseases(β=0.24),comor-bid other mental disorders and physical diseases(β=0.21),physical diseases(β=0.18),comorbid anxiety disor-der and physical diseases(β=0.15),comorbid anxiety disorder with other mental disorders(β=0.08),other men-tal disorders(β=0.07),only anxiety disorder(β=0.06),lower education level(β=0.12),lower economic status(β=0.08),older age(β=0.06),non-marital status(β=0.06),male(β=0.02)and the severity of functional dis-ability.Logistic regression showed that comorbid anxiety with other mental disorders and physical diseases(OR=64.07),comorbid anxiety disorders with other mental disorders(OR=36.75),comorbid other mental disorders with physical diseases(OR=20.60),comorbid anxiety with physical diseases(OR=18.88),anxiety disorder(OR=9.20),other mental disorders(OR=6.65),physical diseases(OR=4.00),65 years old and over(OR=4.40),50 to 64 years old(OR=2.33),low economic status(OR=2.10),illiterate and below primary school educational level(OR=1.89),middle economic status(OR=1.70),elementary school educational level(OR=1.59),non-marital status(OR=1.47),male(OR=1.16)were the risk factors of the occurrence of functional disability.Conclusion:Comorbidity of anxiety disorders and other mental disorders,and physical diseases increases severity and occurrence of functional disability.Comorbidity,male,gender,older age,lower economic and educa-tional level and non-marital are risk factors of anxiety disorder functional disability.
5.A cross-sectional study of disability rate of dementia and risk factors in Chinese old people
Wenlei WU ; Yueqin HUANG ; Zhaorui LIU ; Tingting ZHANG ; Chao MA ; Yifeng XU ; Tao LI ; Xiufeng XU ; Yaqin YU ; Yongping YAN ; Zhizhong WANG ; Xiangdong XU ; Limin WANG ; Qiang LI ; Guangming XU ; Shuiyuan XIAO ; Lingjiang LI
Chinese Mental Health Journal 2024;38(11):936-942
Objective:To describe disability rates of dementia in community residents aged 65 years and over in China,and explore related risk factors of disability.Methods:This study conducted an in-depth data analysis of the China Mental Health Survey.World Health Organization Disability Assessment Schedule 2.0(WHODAS 2.0)was used to assess dementia disability,Community Screening Interview for Dementia(CSID)and Geriatric Mental Status Examination(GMS)were used for dementia screening and diagnosing.Univariate analysis was used to calcu-late the weighted disability rates of dementia in population and in patients,and their population distribution.Multiple linear regression and logistic regression were used to analyze the risk factors of the occurrence of dementia disability and its severity.Results:The weighted disability rate of dementia was 2.1%in population,and 38.6%in pa-tients.The disability rates of comorbid dementia in population and in patients were higher than those of patients with only dementia.Female,older age,lower education level,lower economic status,and lower cognitive test scores in CSID had higher disability rates of dementia in population.Female and urban resident had higher disability rates of dementia in patients.Multiple linear regression showed economic status(β=0.11),gender(β=0.11),age(β=0.10),and treatment in the last 12 months(β=-0.20)were statistically associated with WHODAS 2.0 scores.Multiple logistic regression showed female(OR=2.81)and treatment in the last 12 months(OR=2.38)were statistically associated with disability.Conclusions:Persons with low economic status,female and elderly peo-ple are the high-risk groups for dementia disability.It should be paid attention to prevent dementia and its conse-quential disabilities.
6.Study on the design of the programmed evaluation process and its effect in the management of medical equipment in the emergency department
Liqin MIAO ; Zhi ZHANG ; Caiyun XU ; Mei WANG ; Zhizhong ZHANG
China Medical Equipment 2024;21(7):139-143
Objective:To design a programmed evaluation process,and to explore its application effect in the management of medical equipment in emergency department.Methods:The information management platform was constructed based on IntelliJ IDEA and Java language with browser and server(B/S)architecture,a programmed evaluation process was designed to manage medical equipment in the emergency department.From 2021 to 2022,27 medical devices in use in the emergency department of Beijing Friendship Hospital,Capital Medical University were selected,the programmed evaluation process and the post-evaluation process were adopted respectively for management according to the different equipment management methods.A total of 800 equipment operation logs sampled were analyzed under the two management methods.The timeliness of equipment management,management effect and satisfaction scores of related management personnel were compared between the two management methods.Results:The average time consumption of equipment warning timeliness,timeliness of maintenance personnel's arrival and timeliness of proposed treatment methods in the programmed evaluation process management were(0.92±0.21)min,(5.43±1.08)min and(15.63±2.27)min,respectively,which were lower than those in post-evaluation process management method,the difference was statistically significant(t=13.810,16.893,16.554,P<0.05).The failure rate of 400 logs sampled by the programmed evaluation process management method was 2.75%(11/400),which was lower than that of the post-evaluation process management method,the regular maintenance completion rate was 99.75%(399/400),which was higher than that of the post-evaluation process management method,the difference was statistically significant(x2=18.841,10.778,P<0.05).The equipment maintenance time and equipment maintenance cost of the programmed evaluation process management were(9.32±1.18)days and CNY(201,600±50,500),respectively,which were lower than those of the post-evaluation process management method,and the difference was statistically significant(t=12.663,37.213,P<0.05).The satisfaction scores of maintenance engineers,medical staff and patients in equipment use management for the programmed evaluation process management were(97.25±2.44),(98.63±4.57)and(97.16±3.09),respectively,which were higher than the post-evaluation process management method,and the differences were statistically significant(t=21.284,8.206,5.933,P<0.05).Conclusion:The application of programmed evaluation process to the equipment management of emergency department of the hospital can effectively improve and make up for the loopholes and deficiencies in the conventional equipment management,improve the effect of equipment management,reduce the frequency of equipment failure,and ensure the safe and stable operation of equipment.
7.Analysis of the application effect of ECG monitor operation quality management model based on fuzzy cluster evaluation technology
Mei WANG ; Zhizhong ZHANG ; Yajun YU ; Yanan XU
China Medical Equipment 2024;21(8):137-141
Objective:To construct the operation quality management model of ECG monitor based on fuzzy cluster evaluation technology,and to explore its application effect in ECG monitor operating health management.Methods:The quality management of ECG monitor was carried out from two aspects of fault diagnosis and operation health evaluation,and the evaluation index system of hardware structure and system performance was established.The fuzzy clustering algorithm was used to grade the operation health status,and the equipment classification management and early warning maintenance were carried out according to the evaluation results.The ECG monitor equipment in clinical use in the Emergency Department of Beijing Friendship Hospital Capital Medical University from January to December 2022 was selected,12 devices in clinical use from January to June were managed by conventional ECG monitor monitoring and management method(referred to as conventional management),and 13 devices in clinical use from July to December were managed by constructing a health management model for ECG monitors based on fuzzy clustering evaluation technology(referred to as health management).During the study,a total of 440 alarm parameter data were collected by the conventional management method and 480 alarm parameter data by the health management method,the accuracy of the ECG monitor alarm parameters,the satisfaction score of equipment users and the monthly failure rates of the two groups were compared.Results:The accuracy rate of ECG monitor alarm parameter setting using the health management method was 90.21%(433/480),which was higher than that of the conventional management,he difference was statistically significant(x2=8.265,P<0.05).The scores of equipment users on the system quality,service quality,information quality,net benefit,user satisfaction and total satisfaction of ECG monitors using health management methods were(19.47±3.25),(19.55±4.14),(18.92±2.08),(19.34±2.39),(19.82±3.37)and(97.10±3.39),respectively,which were higher than those using conventional management methods,the differences were statistically significant(t=7.358,4.481,2.859,5.304,2.297,29.001,P<0.05).The ECG monitor using the health management method failed 15 times in 6 months,and the failure incidence rate was 3.97%,which was lower than that of the conventional management method(12.71%),the difference was statistically significant(x2=4.672,P<0.05).Conclusion:The application of ECG monitor operation health management model based on fuzzy clustering evaluation technology to the ECG monitor management in the emergency department can effectively improve the correct alarm rate of the ECG monitor,reduce the failure rate of the ECG monitor,and improve the satisfaction of equipment users.
8.The mediating role of atrial fibrillation in causal associations between risk factors and stroke: a Mendelian randomization study
Shanmei QIN ; Mengmeng WANG ; Dipender GILL ; Zhizhong ZHANG ; Xinfeng LIU
Epidemiology and Health 2024;46(1):e2024005-
OBJECTIVES:
Atrial fibrillation (AF) contributes to stroke development and progression. We aimed to quantify the mediating role of AF in the causal associations between a wide range of risk factors and stroke via a Mendelian randomization (MR) framework.
METHODS:
We assessed the associations of 108 traits with stroke and its subtypes in a 2-sample univariable MR approach, then conducted a bidirectional MR analysis between these 108 traits and AF to evaluate the presence and direction of their causal associations. Finally, to further investigate the extent to which AF mediated the effects of eligible traits on stroke, we applied multivariable and 2-step MR techniques in a mediation analysis where outcomes were restricted to stroke types causally affected by AF (any stroke [AS], any ischemic stroke [AIS], and cardioembolic stroke [CES]).
RESULTS:
Among 108 traits, 42 were putatively causal for at least 1 stroke type; of these 42 traits, 20 that had no bidirectional relationship with AF were retained. Finally, 33 associations of 15 eligible traits were examined in the mediation analysis. The mediation analyses for AS, AIS, and CES each included 11 eligible traits. After AF adjustment, the direct effects of all traits on CES were attenuated to null (all p>0.05), while the associations with AS and AIS persisted for most traits (AF-mediated proportion: from 6.6% [95% confidence interval, 2.7 to 0.6] to 52.0% [95% confidence interval, 39.8 to 64.3]).
CONCLUSIONS
The causal associations between all eligible traits and CES were largely mediated through AF, while most traits affected AS and AIS independently of AF.
9.Efficacy and safety of LY01005 versus goserelin implant in Chinese patients with prostate cancer: A multicenter, randomized, open-label, phase III, non-inferiority trial.
Chengyuan GU ; Zengjun WANG ; Tianxin LIN ; Zhiyu LIU ; Weiqing HAN ; Xuhui ZHANG ; Chao LIANG ; Hao LIU ; Yang YU ; Zhenzhou XU ; Shuang LIU ; Jingen WANG ; Linghua JIA ; Xin YAO ; Wenfeng LIAO ; Cheng FU ; Zhaohui TAN ; Guohua HE ; Guoxi ZHU ; Rui FAN ; Wenzeng YANG ; Xin CHEN ; Zhizhong LIU ; Liqiang ZHONG ; Benkang SHI ; Degang DING ; Shubo CHEN ; Junli WEI ; Xudong YAO ; Ming CHEN ; Zhanpeng LU ; Qun XIE ; Zhiquan HU ; Yinhuai WANG ; Hongqian GUO ; Tiwu FAN ; Zhaozhao LIANG ; Peng CHEN ; Wei WANG ; Tao XU ; Chunsheng LI ; Jinchun XING ; Hong LIAO ; Dalin HE ; Zhibin WU ; Jiandi YU ; Zhongwen FENG ; Mengxiang YANG ; Qifeng DOU ; Quan ZENG ; Yuanwei LI ; Xin GOU ; Guangchen ZHOU ; Xiaofeng WANG ; Rujian ZHU ; Zhonghua ZHANG ; Bo ZHANG ; Wanlong TAN ; Xueling QU ; Hongliang SUN ; Tianyi GAN ; Dingwei YE
Chinese Medical Journal 2023;136(10):1207-1215
BACKGROUND:
LY01005 (Goserelin acetate sustained-release microsphere injection) is a modified gonadotropin-releasing hormone (GnRH) agonist injected monthly. This phase III trial study aimed to evaluated the efficacy and safety of LY01005 in Chinese patients with prostate cancer.
METHODS:
We conducted a randomized controlled, open-label, non-inferiority trial across 49 sites in China. This study included 290 patients with prostate cancer who received either LY01005 or goserelin implants every 28 days for three injections. The primary efficacy endpoints were the percentage of patients with testosterone suppression ≤50 ng/dL at day 29 and the cumulative probability of testosterone ≤50 ng/dL from day 29 to 85. Non-inferiority was prespecified at a margin of -10%. Secondary endpoints included significant castration (≤20 ng/dL), testosterone surge within 72 h following repeated dosing, and changes in luteinizing hormone, follicle-stimulating hormone, and prostate specific antigen levels.
RESULTS:
On day 29, in the LY01005 and goserelin implant groups, testosterone concentrations fell below medical-castration levels in 99.3% (142/143) and 100% (140/140) of patients, respectively, with a difference of -0.7% (95% confidence interval [CI], -3.9% to 2.0%) between the two groups. The cumulative probabilities of maintaining castration from days 29 to 85 were 99.3% and 97.8%, respectively, with a between-group difference of 1.5% (95% CI, -1.3% to 4.4%). Both results met the criterion for non-inferiority. Secondary endpoints were similar between groups. Both treatments were well-tolerated. LY01005 was associated with fewer injection-site reactions than the goserelin implant (0% vs . 1.4% [2/145]).
CONCLUSION:
LY01005 is as effective as goserelin implants in reducing testosterone to castration levels, with a similar safety profile.
TRIAL REGISTRATION
ClinicalTrials.gov, NCT04563936.
Humans
;
Male
;
Antineoplastic Agents, Hormonal/therapeutic use*
;
East Asian People
;
Gonadotropin-Releasing Hormone/agonists*
;
Goserelin/therapeutic use*
;
Prostate-Specific Antigen
;
Prostatic Neoplasms/drug therapy*
;
Testosterone
10.The fliL gene significantly affects the motility and sporulation abilities of Clostridioides difficile.
Jiangjian BAO ; Junyi YANG ; Ruirui SHAO ; Ting ZHANG ; Jian LIAO ; Yumei CHENG ; Zhizhong GUAN ; Xiaolan QI ; Zhenghong CHEN ; Wei HONG ; Guzhen CUI
Chinese Journal of Biotechnology 2023;39(4):1578-1595
Flagella are the main motility structure of Clostridioides difficile that affects the adhesion, colonization, and virulence of C. difficile in the human gastrointestinal tract. The FliL protein is a single transmembrane protein bound to the flagellar matrix. This study aimed to investigate the effect of the FliL encoding gene flagellar basal body-associated FliL family protein (fliL) on the phenotype of C. difficile. The fliL gene deletion mutant (ΔfliL) and its corresponding complementary strains (: : fliL) were constructed using allele-coupled exchange (ACE) and the standard molecular clone method. The differences in physiological properties such as growth profile, antibiotic sensitivity, pH resistance, motility, and spore production ability between the mutant and wild-type strains (CD630) were investigated. The ΔfliL mutant and the : : fliL complementary strain were successfully constructed. After comparing the phenotypes of strains CD630, ΔfliL, and : : fliL, the results showed that the growth rate and maximum biomass of ΔfliL mutant decreased than that of CD630. The ΔfliL mutant showed increased sensitivity to amoxicillin, ampicillin, and norfloxacin. Its sensitivity to kanamycin and tetracycline antibiotics decreased, and the antibiotic sensitivity partially returned to the level of CD630 strain in the : : fliL strain. Moreover, the motility was significantly reduced in the ΔfliL mutant. Interestingly, the motility of the : : fliL strain significantly increased even when compared to that of the CD630 strain. Furthermore, the pH tolerance of the ΔfliL mutant significantly increased or decreased at pH 5 or 9, respectively. Finally, the sporulation ability of ΔfliL mutant reduced considerably compared to the CD630 strain and recovered in the : : fliL strain. We conclude that the deletion of the fliL gene significantly reduced the swimming motility of C. difficile, suggesting that the fliL gene is essential for the motility of C. difficile. The fliL gene deletion significantly reduced spore production, cell growth rate, tolerance to different antibiotics, acidity, and alkalinity environments of C. difficile. These physiological characteristics are closely related to the survival advantage in the host intestine, which is correlated with its pathogenicity. Thus, we suggested that the function of the fliL gene is closely related to its motility, colonization, environmental tolerance, and spore production ability, which consequently affects the pathogenicity of C. difficile.
Humans
;
Clostridioides/metabolism*
;
Clostridioides difficile/metabolism*
;
Bacterial Proteins/metabolism*
;
Virulence
;
Anti-Bacterial Agents/metabolism*

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