1.A systematic review of application value of machine learning to prognostic prediction models for patients with lumbar disc herniation
Zhipeng WANG ; Xiaogang ZHANG ; Hongwei ZHANG ; Xiyun ZHAO ; Yuanzhen LI ; Chenglong GUO ; Daping QIN ; Zhen REN
Chinese Journal of Tissue Engineering Research 2026;30(3):740-748
OBJECTIVE:Based on different algorithms of machine learning,the prediction model of lumbar disc herniation has become a trend and hot spot in the development of precision medicine.However,there is limited evidence on the reporting quality and methodological quality of prediction models of lumbar disc herniation outcomes using machine learning.This article is aimed to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation by comprehensively analyzing the report quality and risk of bias of previous studies that developed and validated prognosis prediction models based on machine learning through a comprehensive literature search,in order to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation.METHODS:The databases of CNKI,WanFang,VIP,SinOMED,PubMed,Web of Science,Embase,and The Cochrane Library were searched by computer.Studies on the use of machine learning to develop(and/or validate)prognostic prediction models for lumbar disc herniation were collected from the inception of the database to December 31,2023.Two researchers independently screened the literature,extracted data,and assessed the risk of bias of the included studies.The reporting quality and risk of bias of the included studies were assessed by the Multivariable Transparent Reporting of Predictive Models(TRIPOD)statement and the Predictive Model Risk of Bias Assessment Tool(PROBAST).The results of the evaluation were analyzed using descriptive statistics and visual charts.RESULTS:(1)A total of 23 articles were included,and the TRIPOD compliance of each study ranged from 11%to 87%,with a median compliance of 54%.The quality of reporting of titles,detailed descriptions of treatment measures,blinding of predictors,handling of missing data,details of risk stratification,specific procedures for enrollment,model interpretation,and model performance was mostly poor,with TRIPOD adherence rates ranging from 4%to 35%.(2)Of all included studies,61%had a high risk of bias and 39%had an unclear overall risk of bias.The area under the curve,accuracy,sensitivity and specificity were used to evaluate the performance of the model.The areas under the curve of 20 models were reported,ranging from 0.561 to 0.999.Three models reported the accuracy of the model,ranging from 82.07%to 89.65%.(3)Among all included studies,the statistical analysis domain was most often assessed as having a high risk of bias,mainly due to the small number of valid samples,the selection of predictors based on univariate analysis and the lack of calibration and discrimination assessment of the model in the study.CONCLUSION:These results indicate that machine learning can achieve good predictive ability in the development and validation of prognostic models for lumbar disc herniation.The commonly used algorithms include regression algorithm,support vector machine,decision tree,random forest,artificial neural network,naive Bayes and other algorithms.Reasonable algorithms combined with clinical practice can improve the accuracy of prognosis prediction of lumbar disc herniation.However,the reporting and methodological quality of prognosis prediction models based on machine learning are poor,the prediction performance of different models varies greatly,and the generalization and extrapolation of research models are unclear.There is an urgent need to improve the design,implementation and reporting of such studies.To promote the application of machine learning in the clinical practice of lumbar disc herniation prediction models,it is necessary to comprehensively consider various predictors related to the prognosis of the disease before modeling,and strictly follow the relevant standards of PROBAST tool during modeling.
2.A systematic review of application value of machine learning to prognostic prediction models for patients with lumbar disc herniation
Zhipeng WANG ; Xiaogang ZHANG ; Hongwei ZHANG ; Xiyun ZHAO ; Yuanzhen LI ; Chenglong GUO ; Daping QIN ; Zhen REN
Chinese Journal of Tissue Engineering Research 2026;30(3):740-748
OBJECTIVE:Based on different algorithms of machine learning,the prediction model of lumbar disc herniation has become a trend and hot spot in the development of precision medicine.However,there is limited evidence on the reporting quality and methodological quality of prediction models of lumbar disc herniation outcomes using machine learning.This article is aimed to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation by comprehensively analyzing the report quality and risk of bias of previous studies that developed and validated prognosis prediction models based on machine learning through a comprehensive literature search,in order to explore the performance of machine learning algorithms in predicting the prognosis of lumbar disc herniation.METHODS:The databases of CNKI,WanFang,VIP,SinOMED,PubMed,Web of Science,Embase,and The Cochrane Library were searched by computer.Studies on the use of machine learning to develop(and/or validate)prognostic prediction models for lumbar disc herniation were collected from the inception of the database to December 31,2023.Two researchers independently screened the literature,extracted data,and assessed the risk of bias of the included studies.The reporting quality and risk of bias of the included studies were assessed by the Multivariable Transparent Reporting of Predictive Models(TRIPOD)statement and the Predictive Model Risk of Bias Assessment Tool(PROBAST).The results of the evaluation were analyzed using descriptive statistics and visual charts.RESULTS:(1)A total of 23 articles were included,and the TRIPOD compliance of each study ranged from 11%to 87%,with a median compliance of 54%.The quality of reporting of titles,detailed descriptions of treatment measures,blinding of predictors,handling of missing data,details of risk stratification,specific procedures for enrollment,model interpretation,and model performance was mostly poor,with TRIPOD adherence rates ranging from 4%to 35%.(2)Of all included studies,61%had a high risk of bias and 39%had an unclear overall risk of bias.The area under the curve,accuracy,sensitivity and specificity were used to evaluate the performance of the model.The areas under the curve of 20 models were reported,ranging from 0.561 to 0.999.Three models reported the accuracy of the model,ranging from 82.07%to 89.65%.(3)Among all included studies,the statistical analysis domain was most often assessed as having a high risk of bias,mainly due to the small number of valid samples,the selection of predictors based on univariate analysis and the lack of calibration and discrimination assessment of the model in the study.CONCLUSION:These results indicate that machine learning can achieve good predictive ability in the development and validation of prognostic models for lumbar disc herniation.The commonly used algorithms include regression algorithm,support vector machine,decision tree,random forest,artificial neural network,naive Bayes and other algorithms.Reasonable algorithms combined with clinical practice can improve the accuracy of prognosis prediction of lumbar disc herniation.However,the reporting and methodological quality of prognosis prediction models based on machine learning are poor,the prediction performance of different models varies greatly,and the generalization and extrapolation of research models are unclear.There is an urgent need to improve the design,implementation and reporting of such studies.To promote the application of machine learning in the clinical practice of lumbar disc herniation prediction models,it is necessary to comprehensively consider various predictors related to the prognosis of the disease before modeling,and strictly follow the relevant standards of PROBAST tool during modeling.
3.Current quality status and management countermeasures of occupational health technical services in Zhejiang Province
Qiuliang XU ; Feng HAN ; Peng WANG ; Zhen ZHOU ; Fei LI ; Hongwei XIE ; Yong HU ; Weiming YUAN ; Lifang ZHOU ; Hua ZOU
Journal of Environmental and Occupational Medicine 2026;43(3):341-346
Background The quality of occupational health technical services is directly linked to the protection of workers' health rights and the efficacy of occupational disease prevention and control. However, the industry still faces critical challenges: sporadic instances of institutional non-compliance and persistent irregularities in professional practice continue to undermine overall service performance. Objective To assess the current quality status of occupational health technical services in Zhejiang Province and propose countermeasures for quality improvement, providing a scientific basis for policy optimization and service delivery quality enhancement. Methods A total of 69 occupational health technical service institutions in Zhejiang Province that obtained formal accreditation as of April 30, 2024, were sampled, including 3 public institutions and 66 private institutions (comprising 3 formerly Class-A, 28 formerly Class-B, 11 formerly Class-C, and 24 newly certified institutions). Following the Technical Protocol for Quality Monitoring of Occupational Health Technical Service in Zhejiang Province and the Technical Protocol for Proficiency Testing of Occupational Health Detection in Zhejiang Province, a quality assessment task force comprising national and provincial experts was established. Evaluation was conducted across four dimensions: qualification maintenance and compliance, standardization of technical services, authenticity of technical services, and proficiency testing, utilizing a combination of document review, on-site inspections, and technical skill assessments. Results The occupational health technical service institutions in Zhejiang Province were predominantly private entities (82.5%), with significant disparities in overall service quality. The pass rates for qualification maintenance and compliance, technical service standardization, technical service authenticity, and the excellence rate for laboratory proficiency testing were 81.5%, 80.7%, 97.3%, and 90.4%, respectively. Regarding qualification maintenance, the pass rates for "environmental conditions" (49.8%, 56.7%) and "instrumentation and equipment" (58.2%、65.6%) were significantly lower for formerly Class-C and newly certified institutions compared to other categories. In terms of technical standardization, "standardized on-site inspections" recorded the lowest pass rate (67.4%), with newly certified institutions at only 48.0%. Regarding technical service authenticity, formerly Class-C institutions exhibited issues such as missing raw chromatograms for blank samples (85.7% pass rate). In laboratory proficiency testing, public and formerly Class-A institutions achieved 100% excellence rates, but the performance of formerly Class-C and newly certified institutions was comparatively weak; specifically, the failure rate for organic analysis in formerly Class-C institutions reached 20%; the failure rate for dust testing items in newly certified institutions was 10.3%. Conclusion The overall quality of occupational health technical services in Zhejiang Province still requires significant improvement, particularly in basic institutional conditions, the standardization of on-site inspections, and laboratory proficiency in organic and dust analysis. Formerly Class-C and newly certified institutions should be the primary focus of quality management efforts. Differentiated regulatory strategies are recommended, alongside strengthening interim and ex-post supervision to gradually enhance the quality of occupational health technical services across all institutions.
4.Successful Pregnancy after Autologous Cryopreserved Ovarian Tissue Transplantation in a Cervical Cancer Patient: the First Reported Case in China
Yubin LI ; Yang ZHANG ; Tian MENG ; Bing CAI ; Chuling WU ; Changxi WANG ; Hongwei SHEN ; Guofen YANG
Journal of Sun Yat-sen University(Medical Sciences) 2025;46(3):498-505
ObjectiveTo investigate the efficacy of ovarian tissue cryopreservation and autologous transplantation in preserving fertility and ovarian endocrine function in patients with cervical cancer. MethodsA 26-year-old patient with stage ⅡA1 cervical cancer underwent ovarian tissue harvesting and cryopreservation during cancer surgery. Following complete remission of the cancer, autologous ovarian tissue transplantation was performed. Follow-up monitoring included assessment of menopausal symptoms, hormone levels, and follicular development. ResultsSix months after transplantation, follicle-stimulating hormone levels decreased to 6.60 U/L, and estradiol levels increased from <10.00 ng/L to 89.00 ng/L. At 10 months after transplantation, ultrasound monitoring confirmed follicular development and physiological ovulation in the transplanted ovarian tissue. By 15 months after transplantation, follicle-stimulating hormone levels remained stable at 7.24 U/L, and estradiol levels further increased to 368.00 ng/L. Over 2 years after transplantation, the patient successfully gave birth to a healthy baby through assisted reproductive technology. ConclusionThe restoration of endocrine and ovulation functions in the transplanted cryopreserved ovarian tissue, followed by successful pregnancy, demonstrates the clinical success of ovarian tissue transplantation.
5.Short- to medium-term safety and efficacy of the implantable Corheart 6 left ventricular assist system in patients with end-stage heart failure
Zhibing QIU ; Xiaochun SONG ; Liangpeng LI ; Hongwei SHI ; Liqiong XIAO ; Yunzhang WU ; Xiaosong RONG ; Jidan FAN ; Liang WEI ; Xin CHEN
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2025;32(05):639-645
Objective To investigate the efficacy and safety of the Corheart 6 left ventricular assist system in patients with end-stage heart failure. Methods A retrospective study was conducted on patients with end-stage heart failure who were treated with Corheart 6 left ventricular assist system from March 2022 to June 2024 in 4 hospitals in Jiangsu Province. The efficacy of the device was evaluated by comparing changes in clinical indicators at preoperative, discharge, 3-month postoperative, and 6-month postoperative timepoints, including the New York Heart Association (NYHA) functional classification, left ventricular ejection fraction (LVEF), and left ventricular end-diastolic diameter (LVEDD). The safety of the device was assessed by analyzing the intraoperative position and orientation of the blood pump inlet cannula, as well as the incidence of adverse events. Results In this study, 39 patients were collected, including 34 males and 5 females with a mean age of (56.4±12.5) years, ranging from 20 to 75 years. There was no operative death. There was no death in postoperative 3 months with a survival rate of 100.0%. There were 3 deaths in 6 months postoperatively, with a survival rate of 92.3%. All patients had a preoperative NYHA cardiac function classification of class Ⅳ. The NYHA cardiac function class of the patients improved (P<0.05) at discharge, 3 and 6 months after surgery when compared to the preoperative period. LVEF was significantly higher at 3 months after surgery than that during the preoperative period (P<0.05). LVEDD was significantly smaller at discharge, 3 and 6 months after surgery than that during the preoperative period (P<0.05). The safety evaluation's findings demonstrated that all 39 patients' intraoperative blood pump inlet tubes were oriented correctly, the artificial blood vessel suture sites were appropriate, there were no instances of device malfunction or pump thrombosis, or instances of bleeding or hemolysis, and the rate of the remaining adverse events was low. Conclusion With a low rate of adverse events and an excellent safety profile, the Corheart 6 left ventricular assist system can efficiently enhance cardiac function in patients with end-stage heart failure. It also has considerable clinical uses.
6.Epidemiological characteristics analysis of pulmonary tuberculosis among children aged 0-14 in Shaanxi Province from 2010 to 2024
HE Zhiqiang, ZHAO Yan, LI Kaikai, ZHANG Hongwei
Chinese Journal of School Health 2025;46(9):1346-1350
Objective:
To analyze the epidemiological characteristics and incidence trends of pulmonary tuberculosis (TB) in children aged 0-14 years in Shaanxi Province from 2010 to 2024, so as to provide a reference for optimizing child TB prevention and control strategies.
Methods:
Data on pulmonary TB cases in children aged 0-14 years and demographic information in Shaanxi Province from 2010 to 2024 were collected from Surveillance and Reporting Management System with Disease Prevention and Control Information Management System under the National Health Security Informatization Project Disease Prevention and Control Information System. A Joinpoint regression model was established to analyze the temporal, spatial, and population distribution trends of child pulmonary TB incidence.
Results:
A total of 2 954 cases of pulmonary TB in children aged 0-14 years were reported in Shaanxi Province from 2010 to 2024, accounting for 0.97% of all TB cases in the general population. The average annual reported incidence rate in children was 3.32 per 100 000. Among these cases, 804 were pathogenetically positive, showing a increasing trend ( χ 2 trend =420.94, P < 0.01 ). The overall reported incidence rate of pulmonary TB in children aged 0-14 years in Shaanxi Province showed a decreasing trend, dropping from 5.35 per 100 000 in 2010 to 2.41 per 100 000 in 2024. Joinpoint regression analysis identified three distinct phases for the reported incidence rate of TB:a rapid decline from 2010 to 2013 (APC=-20.02%, 95% CI = -33.64% to -10.42%), a slight increase from 2013 to 2017 (APC=11.18%, 95% CI =3.07%-24.17%) and a slight decline again from 2017 to 2024 (APC= -7.27 %, 95% CI =-12.73% to -4.30%) (all P <0.01). Among children aged 0-14 years, the age group with the highest average annual reported incidence rate was 10-14 years (8.02 per 100 000), followed by 5-9 years (1.44 per 100 000), and 0-4 years had the lowest rate (0.95 per 100 000). The difference in reported incidence rates among the three age groups was statistically significant ( χ 2= 51.91, P <0.01). The average annual reported incidence rate of TB was 3.25 per 100 000 in boys and 3.39 per 100 000 in girls, with no statistically significant difference ( χ 2=2.01, P >0.05). There was no obvious periodic variation in the annual case reporting. Among all cities in Shaanxi Province, Ankang City had the highest average annual reported incidence rate (5.16 per 100 000).
Conclusions
From 2010 to 2024, the reported incidence rate of pulmonary TB in children aged 0-14 years in Shaanxi Province showed an overall decreasing trend. However, it is still necessary to strengthen active surveillance, implement targeted measures in high incidence areas such as Ankang City, and maintain continuous attention to child TB prevention and control.
7.Effects of acupuncture on podocyte autophagy and the LncRNA SOX2OT/mTORC1/ULK1 pathway in rats with diabetic kidney disease.
Xu WANG ; Yue ZHANG ; Hongwei LI ; Handong LIU ; Jie LI ; Ying FAN ; Zhilong ZHANG
Chinese Acupuncture & Moxibustion 2025;45(10):1450-1458
OBJECTIVE:
To observe the effects of acupuncture on podocyte autophagy and long non-coding RNA SOX2 overlapping transcript (LncRNA SOX2OT)/mammalian target of rapamycin C1 (mTORC1)/Unc-51-like kinase 1 (ULK1) pathway in rats with diabetic kidney disease (DKD), and to explore the mechanism by which acupuncture reduces urinary protein.
METHODS:
A total of 40 SPF-grade male Sprague-Dawley rats were randomly divided into a control group (n=10) and a modeling group (n=30). The DKD model was established by feeding a high-fat, high-sugar diet combined with intraperitoneal injection of streptozotocin (STZ) in the modeling group. Twenty rats with successful DKD model were randomly divided into a model group (n=10) and an acupuncture group (n=10). The acupuncture group received "spleen and stomach-regulating" acupuncture at bilateral "Zusanli" (ST36), "Fenglong" (ST40), "Yinlingquan" (SP9), and "Zhongwan" (CV12), 30 min per session, once daily, five times per week, for four weeks. The general condition, fasting blood glucose (FBG), 2-hour postprandial glucose (2hPG), serum creatinine (SCr), blood urea nitrogen (BUN), 24-hour urinary protein quantification, and urine albumin-to-creatinine ratio (UACR) were compared before and after the intervention. After intervention, urinary podocyte injury marker SPON2 was measured by ELISA. Podocyte autophagosomes and glomerular basement membrane ultrastructure in renal tissue were observed via transmission electron microscopy. Podocyte apoptosis was assessed by TUNEL staining. The protein expression of microtubule-associated protein 1 light chain 3Ⅱ (LC3-Ⅱ), mTORC1, ULK1, Beclin-1, and p62 in renal tissue was detected by Western blot. LncRNA SOX2OT expression in renal tissue was measured by real-time PCR.
RESULTS:
After the intervention, compared with the control group, the model group exhibited increased food and water intake, increased urine output, weight loss, and loose stools; compared with the model group, the food and water intake, urine volume, and loose stools were improved in the acupuncture group. Compared with the control group, FBG, 2hPG, SCr, BUN, 24-hour urinary protein quantification, UACR, and urinary SPON2 were all higher in the model group (P<0.01); compared with the model group, the FBG, 2hPG, SCr, BUN, 24-hour urinary protein quantification, UACR, and urinary SPON2 were all lower in the acupuncture group (P<0.01). Compared with the control group, the model group showed reduced podocyte autophagosomes and thickened glomerular basement membrane; compared with the model group, the acupuncture group had increased podocyte autophagosomes and less thickened basement membrane. Compared with the control group, the podocyte apoptosis index (AI) was higher in the model group (P<0.01); compared with the model group, the AI was lower in the acupuncture group (P<0.01). Compared with the control group, the expression of ULK1, Beclin-1, and LC3-Ⅱ proteins was lower, and the expression of mTORC1 and p62 proteins was higher in the model group (P<0.01). Compared with the model group, the expression of ULK1, Beclin-1, and LC3-Ⅱ proteins was higher, and the expression of mTORC1 and p62 proteins was lower in the acupuncture group (P<0.01). Compared with the control group, the LncRNA SOX2OT expression was lower in the model group (P<0.01). Compared with the model group, LncRNA SOX2OT expression was higher in the acupuncture group (P<0.01).
CONCLUSION
The "spleen and stomach-regulating" acupuncture method could improve renal function in DKD rats, reduce blood glucose and urinary protein excretion, alleviate podocyte injury, and enhance podocyte autophagy. The mechanism may be related to modulation of the renal LncRNA SOX2OT/mTORC1/ULK1 pathway.
Animals
;
Podocytes/cytology*
;
Diabetic Nephropathies/physiopathology*
;
Rats, Sprague-Dawley
;
Male
;
Rats
;
Mechanistic Target of Rapamycin Complex 1/genetics*
;
Autophagy
;
Acupuncture Therapy
;
Autophagy-Related Protein-1 Homolog/genetics*
;
RNA, Long Noncoding/metabolism*
;
Humans
;
Signal Transduction
8.A systematic review of tools for assessing the readiness of patients with chronic diseases aged 10-19 to transition to adulthood
Sa WANG ; Huali MIAO ; Yuwei LI ; Hongwei WANG ; Caicai QIAO ; Weiting SONG
Chinese Journal of Nursing 2025;60(4):469-477
Objective To systematically evaluate the assessment tools of adolescent chronic disease patients'transition readiness to adults at home and abroad,and to provide references for medical personnel to choose appropriate tools.Methods CNKI,Wan Fang Data,CBM,PubMed,Web of Science,Embase and Cochrane were searched for literature related to the assessment tools of transition readiness in adolescents with chronic illnesses to adulthood from inception to August,2024.Literature screening and data extraction of the tools were extracted independently by 2 researchers.At the same time,the criteria for the selection of health measurement tools based on consensus(COSMIN)systematic evaluation guidelines were used to evaluate the inclusion assessment tools,and recommendations were finally formed.Results A total of 29 articles were included,involving 9 universal and 5 specific assessment tools of adolescent chronic illnesses transition readiness.The Transition Readiness Assessment Questionnaire has satisfactory content validity and internal consistency,and it is recommended as Grade A.The Grade C included the Am I ON TRAC for adult care?Questionnaire and the State Assessment Questionnaire for Transition,Epilepsy-specific Transition Readiness Assessment Questionnaire and the Readiness for Adult Care in Rheumatology,while the others are recommended as Grade B.Conclusion There are a variety of tools to assess the transition readiness of adolescents with chronic diseases to adults,and there are few tools suitable for adolescents with chronic diseases in China,with few specific tools.After comprehensive consideration,the Transition Readiness Assessment Questionnaire can be recommended temporarily.
9.Establishment and application of a colloidal gold immunochromatographic test strip assay for detection of caprine enterovirus
Xuebo ZHENG ; Xuyuan CUI ; Naitian YAN ; Qianying WANG ; Hongwei LI ; Lihui CHEN ; Wenjie GONG ; Xinping WANG
Chinese Journal of Veterinary Science 2025;45(4):662-667
To establish an immunochromatographic method for rapid detection of caprine enterovir-us(CEV),the monoclonal antibody against CEV VP1 protein was used as gold-labeled monoclonal antibodies,and the purified rabbit-derived polyclonal antibody of CEV-VP1 and sheep anti-mouse IgG were used as the detection line and quality control line,respectively.The colloidal gold immu-nochromatographic test strips for CEV were prepared according to the principle of double antibody sandwich,evaluated,and applied for clinical specimen detection.The results showed that the meth-od specifically recognized CEV without cross-reaction with bovine enterovirus and bovine viral di-arrhea virus.The minimum detection limit of the method was 102.49 TCID50/mL and had good re-producibility.The prepared test strips had a shelf life of three months kept at 4 ℃.Detection of clin-ical samples using the immunochromatographic test strips showed 100%coincidence rate with RT-PCR method.In conclusion,the colloidal gold immunochromatographic test strips for detection of the emerging CEV with good specificity,sensitivity and repeatability,which provides a new techni-cal means easily used for the rapid detection/diagnosis and epidemiological investigation on CEV infection.
10.Identification and biological characteristics analysis of diarrhea E.coli in dairy and meat calves in livestock farms in Northern Hebei
Zhaoxing ZHANG ; Jianghong HENG ; Hongwei ZHANG ; Yanying ZHANG ; Yan ZHANG ; Peiguo LI
Chinese Journal of Veterinary Science 2025;45(4):693-698
This study aims to analyze the biological characteristics such as pathogenicity,serotype,virulence genes,and drug resistance of Escherichia coli(E.coli)causing diarrhea in dairy and meat calves in different farms in the Northern Hebei.From 2022 to 2023,120 diseased tissue sam-ples(feces,anal swabs,and livers)of calves(0-2 months old)suffering from diarrhea in the north-ern Hebei region were collected.The detection of viral and parasitic pathogens was negative.Bacte-rial isolation and cultivation,morphological observation,biochemical identification,and PCR meth-ods were used to identify E.coli.Biological characteristics such as pathogenicity,serum typing,vir-ulence genes,and drug resistance were detected using mouse virulence test,glass plate agglutina-tion test,PCR method,and K-B drug sensitivity paper method,and determine the median lethal dose(LD50)of representative strains of dominant serotypes in mice respectively.The results showed that 76 strains of E.coli were isolated,and 56 strains were pathogenic E.coli that could cause varying degrees of death in mice,with mortality rates all above 40%.Among 56 pathogenic E.coli strains,O6 and O152 were the dominant pathogenic serotypes,among which 48 strains(85.7%)were enterotoxic E.coli(ETEC),6 strains(10.7%)were enteropathogenic E.coli(EPEC),and 2 strains(3.6%)were enterohemorrhagic E.coli(EHEC).The detection rates of vir-ulence genes fyuA,irp2,fliC,stx1,stx2,K88,K99,eaeA and ler were over 50%,while the de-tection rates of other types of virulence genes were 3.6%to 37.0%.The resistance rates to nine drugs such as ampicillin,neomycin,and amoxicillin were over 42.9%,and the resistance rates to other drugs were 12.5%to 32.1%,showing multiple drug resistance and at least resistance to three types of antibiotics.The LD50 values of the dominant serotype of representative strains ETO 152 strain and EPO6 were 3.16×104 and 3.22×106 CFU/mL,respectively.This study can provide ref-erence for the prevention and control of E.coli disease in dairy and meat calves in the Northern Hebei region.


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