Objective Objective To analyze the potential spatial factors affecting the genetic differentiation of Oncomelania hupensis robertsoni in Yunnan Province. Methods A total of 13 administrative villages were selected from schistosomiasis-endemic areas of Yunnan Province as O. hupensis snail sampling sites. At least 200 snails were collected in each site, and the spatial variable data of each site were recorded, including longitude, latitude and altitude. Thirty active and Schistosoma japonicum uninfected O. hupensis snails were selected from each sampling site by means of the crawling method and the cercarial shedding method. Genomic DNA was extracted from O. hupensis snails. Following PCR amplification, purification of PCR amplification products and sequencing, the gene sequences of O. hupensis snail samples were spliced and edited using the DNAstar software and the NCBI database to yield the complete mitochondrial sequences of O. hupensis snails at each sampling site, and the mitochondrial genetic distance matrix of O. hupensis robertsoni was calculated at each sampling site. The geographical coordinates of each sampling site were marked using the software ArcGIS 10.2, and the straight-line geographical distance between each sampling site was calculated. The altitude difference, longitude difference and latitude difference between each sampling site were calculated using the Excel software, and the correlation between the mitochondrial genetic distance matrix of O. hupensis robertsoni and each spatial variable matrix was examined by using the Mantel test at 13 sampling sites in Yunnan Province. Results Among the 13 O. hupensis snail sampling sites in Yunnan Province, the largest mitochondrial genetic distance of O. hupensis robertsoni snail populations was seen between Anding Village, Nanjian Yi Autonomous County and Caizhuang Village, Midu County (26.244 2), and the largest geographical distance was seen between Dongyuan Village, Gucheng District and Cangling Village, Chuxiong County (272.64 km). The highest altitude difference was seen between Anding Village, Nanjian Yi Autonomous County and Dongyuan Village, Gucheng District (1 086.10 m), and the largest longitude difference was found between Qiandian Village, Eryuan County and Cangling Village, Chuxiong County (1.86°), while the largest latitude difference was measured between Leqiu Village, Nanjian Yi Autonomous County and Dongyuan Village, Gucheng District (1.81°). In addition, the mitochondrial genetic distance of O. hupensis robertsoni snail populations was positively correlated with altitude at 13 snail sampling sites in Yunnan Province (r = 0.542 8, P < 0.001), and showed no significant correlations with geographical distance (r = 0.093 4, P > 0.05), longitude (r = −0.199 5, P > 0.05) or latitude (r = 0.205 7, P > 0.05). Conclusion Altitude may be a potential spatial factor affecting the genetic differentiation of O. hupensis robertsoni in Yunnan Province.

ObjectiveTo observe the clinical efficacy and safety of Yuyin Lidan granules （YYLD） in preventing the recurrence of common bile duct stones （CBDS） in patients with liver and gallbladder dampness-heat syndrome following endoscopic retrograde cholangiopancreatography （ERCP）. MethodsThis randomized， parallel， controlled trial enrolled postoperative CBDS-ERCP patients who met the inclusion and exclusion criteria. Sixty-four patients were randomly assigned to an observation group or a control group， with 32 cases in each. Both groups received conventional Western medical treatment after ERCP， while the observation group additionally received YYLD for 8 weeks. The follow-up period lasted for 1 year. The efficacy indicators included bile bilirubin levels， traditional Chinese medicine （TCM） syndrome scores， clinical efficacy rate， pancreatitis and inflammation markers， postoperative liver function， and CBDS recurrence rate at 1-year follow-up， which were used to jointly evaluate the clinical efficacy and safety of both groups. ResultsA total of 56 patients completed the study and were included in the final analysis， i.e.， 29 in the observation group and 27 in the control group. Baseline characteristics were comparable between the two groups. Compared with pre-treatment and with the control group after treatment， the bile bilirubin level in the observation group significantly decreased （P<0.05）. After treatment， the clinical cure and marked improvement rates were higher in the observation group than in the control group， showing a statistically significant difference in overall clinical efficacy （P<0.05）. Compared with pre-treatment， the primary and secondary symptoms in the observation group， as well as the primary symptom and the secondary symptom of nausea and vomiting in the control group （weeks 4 and 8）， were significantly reduced （P<0.05）. Compared with the control group after treatment， the observation group showed significant reductions in the primary symptom of loose stools/constipation （day 5 and week 4） and in three secondary symptoms， i.e.， bitter taste and sticky dry mouth， abdominal distension and poor appetite （throughout the treatment period）， and general heaviness and fatigue （day 5 and week 4）， with statistical differences （P<0.05）. Compared with pre-treatment， both groups showed decreased lipase and urinary amylase levels （P<0.05）. However， no significant between-group differences were observed in pancreatitis or inflammation-related indices after treatment. Compared with pre-treatment， all liver function indicators in the observation group and alanine aminotransferase （ ALT ）， γ-glutamyl transferase （ γ-GT ）， alkaline phosphatase （ALP）， and conjugated bilirubin in the control group significantly decreased at weeks 4 and 8 （P<0.05）. Compared with the control group after treatment， only serum total bilirubin and unconjugated bilirubin were significantly reduced in the observation group during the treatment period （P<0.05）. ConclusionYYLD combined with conventional Western medical treatment can effectively regulate bilirubin metabolism （in bile and serum）， improve TCM clinical symptoms， and prevent CBDS recurrence after ERCP in patients with liver and gallbladder dampness-heat syndrome. This regimen is safe and effective and is worthy of further clinical research and promotion.

Diabetic kidney disease（DKD） is a chronic kidney structural and functional disorder caused by diabetes. With the global prevalence of diabetes continuing to rise， DKD has gradually become a major cause of chronic kidney disease and end-stage renal disease（ESRD）， posing a serious threat to patients' quality of life and long-term health outcomes. Studies have shown that apoptosis plays a pivotal role in the development and progression of DKD， with its mechanisms involving abnormal activation of multiple signaling pathways such as Toll-like receptor 4（TLR4）/nuclear transcription factor-κB（NF-κB）/B-cell lymphoma-2（Bcl-2）/cysteinyl aspartate-specific proteinase（Caspase）-3， protein kinase R-like endoplasmic reticulum kinase（PERK）/eukaryotic initiation factor 2α（eIF2α）/activating transcript factor 4（ATF4）/CCAAT enhancer-binding protein homologous protein（CHOP）， phosphatidylinositol 3-kinase（PI3K）/protein kinase B（Akt）/glycogen synthase kinase-3β（GSK-3β）， Janus kinase 2（JAK2）/signal transducer and activator of transcription 3（STAT3）， adenosine monophosphate-activated protein kinase（AMPK）/mammalian target of rapamycin（mTOR） and silent information regulator 1（SIRT1）/tumor suppressor protein 53（p53）， thereby accelerating renal pathological damage in DKD. Extensive evidence-based medical studies have confirmed that traditional Chinese medicine（TCM）， leveraging its unique therapeutic advantages of multi-target， multi-component and multi-pathway approaches， has demonstrated remarkable efficacy and favorable safety profiles in treating DKD. Recent studies have demonstrated that active components of TCM can specifically target and modulate key effectors in apoptotic signaling pathways. Meanwhile， traditional compound formulations exert synergistic effects through multiple approaches such as replenishing deficiency and activating blood circulation， detoxifying and dredging collaterals， tonifying kidney essence， and removing stasis and purging turbidity， thereby comprehensively regulating critical pathological processes including endoplasmic reticulum stress and mitochondrial apoptosis pathways. This combined therapeutic approach of molecular targeting and holistic regulation provides novel strategies for delaying the progression of DKD. Based on this， this paper provides an in-depth analysis of key apoptotic signaling pathways and their regulatory mechanisms， while systematically summarizing recent research advances regarding the therapeutic effects of TCM active components， compound formulations， and proprietary Chinese medicines on DKD through modulation of these pathways， with particular emphasis on their underlying molecular mechanisms. These findings not only elucidate the modern scientific connotation and theoretical basis of TCM in treating DKD but also establish a solid theoretical and practical foundation for promoting the wider clinical application and further research of TCM in the field of DKD treatment.

BACKGROUND:Currently,there are many modeling methods for pelvic organ prolapse animal models,and the commonly used methods are vaginal balloon dilatation,oophorectomy and the combination of the two.There is no study comparing the three modeling methods in detail.OBJECTIVE:To construct and validate a rat animal model of pelvic organ prolapse using three different methods and to identify the advantages and disadvantages of various models.METHODS:Seventy-two 8-week SPF-grade female Sprague-Dawley rats were selected and randomly divided into four groups,namely,vaginal balloon dilatation group,ovariectomy group,ovariectomy combined with vaginal balloon dilatation group(the combined group),and the sham-operated group(no ovariectomy and no vaginal dilatation).The vaginal wall tissues of rats were collected at 4,8 and 12 weeks after the operation for hematoxylin-eosin staining,Masson staining,EVG staining and immunohistochemical staining of α-smooth muscle actin,Vimentin and matrix metalloproteinase 9 detection,and the pelvic floor muscle tissues were taken at 4,8 and 12 weeks after the operation for hematoxylin-eosin staining,Masson staining and EVG staining.RESULTS AND CONCLUSION:(1)Hematoxylin-eosi staining showed that there was no significant difference in the decrease of vaginal epithelial layer thickness in the vaginal balloon dilatation group compared with the sham-operated group,(P＞0.05),while the thickness of the vaginal epithelial layer was significantly reduced in the ovariectomy group and the ovariectomy combined with vaginal balloon dilation group(P＜0.001),and the reduction was more significant in the ovariectomy combined with vaginal balloon dilation group,remained stable at 8 weeks after surgery and lasted until 12 weeks.(2)The changes in the content of collagen fibers and elastic fibers in the vaginal wall stained by Masson and EVG staining were the same as the changes in the thickness of the vaginal epithelial layer stained by hematoxylin-eosin,and there were no changes in collagen fibers and elastic fibers in the pelvic floor muscle tissues of the treatment groups.(3)At 4,8 and 12 weeks after treatment,there was no significant difference in the expression levels of α-smooth muscle actin,Vimentin and matrix metalloproteinase 9 in the vaginal wall tissue of the balloon dilation group compared with the control group(P＞0.05),whereas the expression levels of α-smooth muscle actin and Vimentin were significantly decreased in the ovariectomy group and ovariectomy combined with vaginal balloon dilation group(P＜0.01)and the expression of matrix metalloproteinase 9 showed a significant increase(P＜0.01),with a more pronounced increase in the ovariectomy combined with vaginal balloon dilation group,and the increase reached a stable state at 8 weeks after surgery and could persist up to 12 weeks.To conclude,vaginal balloon dilatation could not maintain the degeneration of pelvic organ prolapse formed by the vaginal wall for a long period,and both ovariectomy and the combined method can be used.Ovariectomy combined with vaginal balloon dilatation can significantly accelerate and aggravate the formation of typical histological features of pelvic organ prolapse in vaginal wall tissues,effectively shorten the experimental period,and improve the efficiency.These effects reach a stable state at 8 weeks after surgery and can be sustained up to 12 weeks,which is practical and convenient for the study of pelvic organ prolapse animal models.

BACKGROUND:Currently,there are many modeling methods for pelvic organ prolapse animal models,and the commonly used methods are vaginal balloon dilatation,oophorectomy and the combination of the two.There is no study comparing the three modeling methods in detail.OBJECTIVE:To construct and validate a rat animal model of pelvic organ prolapse using three different methods and to identify the advantages and disadvantages of various models.METHODS:Seventy-two 8-week SPF-grade female Sprague-Dawley rats were selected and randomly divided into four groups,namely,vaginal balloon dilatation group,ovariectomy group,ovariectomy combined with vaginal balloon dilatation group(the combined group),and the sham-operated group(no ovariectomy and no vaginal dilatation).The vaginal wall tissues of rats were collected at 4,8 and 12 weeks after the operation for hematoxylin-eosin staining,Masson staining,EVG staining and immunohistochemical staining of α-smooth muscle actin,Vimentin and matrix metalloproteinase 9 detection,and the pelvic floor muscle tissues were taken at 4,8 and 12 weeks after the operation for hematoxylin-eosin staining,Masson staining and EVG staining.RESULTS AND CONCLUSION:(1)Hematoxylin-eosi staining showed that there was no significant difference in the decrease of vaginal epithelial layer thickness in the vaginal balloon dilatation group compared with the sham-operated group,(P＞0.05),while the thickness of the vaginal epithelial layer was significantly reduced in the ovariectomy group and the ovariectomy combined with vaginal balloon dilation group(P＜0.001),and the reduction was more significant in the ovariectomy combined with vaginal balloon dilation group,remained stable at 8 weeks after surgery and lasted until 12 weeks.(2)The changes in the content of collagen fibers and elastic fibers in the vaginal wall stained by Masson and EVG staining were the same as the changes in the thickness of the vaginal epithelial layer stained by hematoxylin-eosin,and there were no changes in collagen fibers and elastic fibers in the pelvic floor muscle tissues of the treatment groups.(3)At 4,8 and 12 weeks after treatment,there was no significant difference in the expression levels of α-smooth muscle actin,Vimentin and matrix metalloproteinase 9 in the vaginal wall tissue of the balloon dilation group compared with the control group(P＞0.05),whereas the expression levels of α-smooth muscle actin and Vimentin were significantly decreased in the ovariectomy group and ovariectomy combined with vaginal balloon dilation group(P＜0.01)and the expression of matrix metalloproteinase 9 showed a significant increase(P＜0.01),with a more pronounced increase in the ovariectomy combined with vaginal balloon dilation group,and the increase reached a stable state at 8 weeks after surgery and could persist up to 12 weeks.To conclude,vaginal balloon dilatation could not maintain the degeneration of pelvic organ prolapse formed by the vaginal wall for a long period,and both ovariectomy and the combined method can be used.Ovariectomy combined with vaginal balloon dilatation can significantly accelerate and aggravate the formation of typical histological features of pelvic organ prolapse in vaginal wall tissues,effectively shorten the experimental period,and improve the efficiency.These effects reach a stable state at 8 weeks after surgery and can be sustained up to 12 weeks,which is practical and convenient for the study of pelvic organ prolapse animal models.

Objective To investigate the distribution characteristics of Oncomelania hupensis snails in Yunnan Province fol-lowing interruption of schistosomiasis transmission, so as to provide the evidence for assessing the risk of schistosomiasis transmission and scientifically formulating the schistosomiasis surveillance program. Methods According to the requirements of the National Schistosomiasis Surveillance Scheme (2020 Edition), O. hupensis snail surveillance data were collected from 18 schistosomiasis-endemic counties (cities, districts) in Yunnan Province from 2020 to 2024, including area of snail survey, area of snail habitats, area of re-emerging snail habitats, number of frames surveyed, number of frames with O. hupensis snails, number of O. hupensis snails captured, and number of living snails, and the occurrence of frames with snails and mean density of living snails were calculated. Changes in snail status over the 5-year period from 2020 to 2024 and the differences in snail distributions specified by epidemic intensity, environmental type, and vegetation type were analyzed. Results The areas of snail survey increased from 1 727.96 hm² in 2020 to 3 894.45 hm² in 2024 (peak) across 18 schistosomiasis-endemic counties (cities, districts) in Yunnan Province during the period from 2020 through 2024. The areas of snail habitats increased from 70.36 hm² in 2020 to a peak in 2023 (172.04 hm²), followed by a reduction to 132.36 hm² in 2024, and the areas of re-emerging snail habitats increased from 42.71 hm² in 2020 to a peak in 2022 (78.43 hm²), followed by a reduction to 40.21 hm² in 2024. The occurrence of frames with snails and mean density of living snails increased from 1.24% (3 025/244 404) and (0.033 2 ± 0.038 7) snails/0.1 m² in 2020 to peaks at 2.03% (6 231/307 563) and (0.066 9 ± 0.068 4) snails/0.1 m² in 2023, followed by reductions to 1.04% (5 829/559 941) and (0.032 6 ± 0.057 7) snails/0.1 m² in 2024, respectively. There was a significant difference in the occurrence of frames with snails over the 5-year study period (χ² = 1 962.95, P < 0.05), and the occurrence of frames with snails reduced by 48.71% in 2024 relative to in 2023 (χ² = 1 411.05, P < 0.005); however, there was no significant difference in the mean density of living snails over the 5 years (H = 5.310, P > 0.05). There were significant differences in the occurrence of frames with snails (χ² = 481.27, P < 0.05) and mean density of living snails (H = 6.872, P < 0.05) in schistosomiasis-endemic areas with different epidemic intensities. The occurrence of frames with snails (χ² = 25.32 and 38.70, both P values < 0.017) and mean density of living snails (Z = 28.55 and 49.96, both P values < 0.017) were higher in schistosomiasis transmission-interrupted and eliminated areas with snails than in schistosomiasis-eliminated areas without snails, and the occurrence of frames with snails (χ² = 453.54, P < 0.017) and mean density of living snails (Z = −56.97, P < 0.017) were higher in schistosomiasis-eliminated areas with snails than in schistosomiasis transmission-interrupted areas with snails. O. hupensis snails were mainly distributed in paddy fields, dry farmlands and ditches; however, the occurrence of frames with snails (13.40%, 424/3 164) and mean density of living snails [(0.252 8 ± 0.158 7) snails/0.1 m²] were higher in ponds/weirs than in other types of environments (both P values < 0.05). Rice, dry farmland crops and weeds were main vegetations in which O. hupensis snails were distributed, and the occurrence of frames with snails (2.29%, 7 111/310 140) and mean density of living snails [(0.072 3 ± 0.018 9) snails/0.1 m²] were higher in weeds than in other types of environments (both P values < 0.05). Conclusions O. hupensis snails have been effectively controlled in Yunnan Province following implementation of integrated schistosomiasis control measures; however, there are still risk factors for schistosomiasis transmission, including reduced attention to schistosomiasis control and snail re-emergence. Improved control efforts and surveillance system construction and timely identification of risk factors of snail status and timely management are recommended to ensure the achievement of the target of schistosomiasis elimination as scheduled.

ObjectiveTo establish a model that can quickly identify the aroma components in different parts of Nardostachys jatamansi， so as to provide a quality control basis for the market circulation and clinical use of N. jatamansi. MethodsHeadspace solid-phase microextraction-gas chromatography-mass spectrometry（HS-SPME-GC-MS） combined with Smart aroma database and National Institute of Standards and Technology（NIST） database were used to characterize the aroma components in different parts of N. jatamansi， and the aroma components were quantified according to relative response factor（RRF） and three internal standards， and the markers of aroma differences in different parts of N. jatamansi were identified by orthogonal partial least squares-discriminant analysis（OPLS-DA） and cluster thermal analysis based on variable importance in the projection（VIP） value >1 and P<0.01. The odor data of different parts of N. jatamansi were collected by Heracles Ⅱ Neo ultra-fast gas phase electronic nose， and the correlation between compound types of aroma components collected by the ultra-fast gas phase electronic nose and the detection results of HS-SPME-GC-MS was investigated by drawing odor fingerprints and odor response radargrams. Chromatographic peak information with distinguishing ability≥0.700 and peak area≥200 was selected as sensor data， and the rapid identification model of different parts of N. jatamansi was established by principal component analysis（PCA）， discriminant factor alysis（DFA）， soft independent modeling of class analogies（SIMCA） and statistical quality control analysis（SQCA）. ResultsThe HS-SPME-GC-MS results showed that there were 28 common components in the underground and aboveground parts of N. jatamansi， of which 22 could be quantified and 12 significantly different components were screened out. Among these 12 components， the contents of five components（ethyl isovalerate， 2-pentylfuran， benzyl alcohol， nonanal and glacial acetic acid，） in the aboveground part of N. jatamansi were significantly higher than those in the underground part（P<0.01）， the contents of β-ionone， patchouli alcohol， α-caryophyllene， linalyl butyrate， valencene， 1，8-cineole and p-cymene in the underground part of N. jatamansi were significantly higher than those in the aboveground part（P<0.01）. Heracles Ⅱ Neo electronic nose results showed that the PCA discrimination index of the underground and aboveground parts of N. jatamansi was 82， and the contribution rates of the principal component factors were 99.94% and 99.89% when 2 and 3 principal components were extracted， respectively. The contribution rate of the discriminant factor 1 of the DFA model constructed on the basis of PCA was 100%， the validation score of the SIMCA model for discrimination of the two parts was 99， and SQCA could clearly distinguish different parts of N. jatamansi. ConclusionHS-SPME-GC-MS can clarify the differential markers of underground and aboveground parts of N. jatamansi. The four analytical models provided by Heracles Ⅱ Neo electronic nose（PCA， DFA， SIMCA and SQCA） can realize the rapid identification of different parts of N. jatamansi. Combining the two results， it is speculated that terpenes and carboxylic acids may be the main factors contributing to the difference in aroma between the underground and aboveground parts of N. jatamansi.

Background: Psoralea corylifolia L. (Buguzhi, BGZ), known for its efficacy in supporting pregnancy and preventing miscarriage, has been used in China for over 1000 years. Recently, BGZ has been identified as a potential cause of drug-induced liver injury. However, its safety during pregnancy remains unclear, which significantly hinders its routine clinical application. Objective: To investigate the effects of BGZ administration during pregnancy on the liver of mouse mothers and their weaned 21-day-old offspring. Methods: Mice were orally administered BGZ at doses of 2.5 and 10 g/kg during pregnancy, with BGZ withdrawal during the lactation period. Liver histopathology (hematoxylin-eosin staining), biochemical analysis, and evaluation of liver bile acid metabolism were performed after the lactation period. Results: BGZ administration at doses of 2.5 and 10 g/kg during pregnancy, followed by withdrawal during the lactation period, caused mild liver damage in both mothers and their 21-day-old offspring. Serum total bile acid (TBA) levels were elevated compared with those in the control group. Additionally, changes were observed in the levels and proportions of various bile acids (BAs) in the liver, suggesting mild effects on BA metabolism. Conclusion: BGZ administration during pregnancy caused mild liver damage and increased serum TBA levels in both mouse mothers and their 21-day-old offspring. This phenomenon may be associated with imbalanced BA metabolism in the liver. Based on the present study and the limited toxicological research on BGZ, pregnant women should avoid prolonged use of BGZ. If BGZ is administered during pregnancy, serum TBA levels should be monitored, and if elevated, BGZ should be discontinued.

Background: Aristolochic acid II (AAII), a major nephrotoxic and carcinogenic component of aristolochic acids (AAs), has been less studied compared with its well-characterized analog, aristolochic acid I (AAI). Although AAs are known to induce carcinogenesis via DNA adduct formation, the toxicity mechanisms, environmental prevalence, and long-term health impacts of AAII remain poorly understood. Objective: This study aimed to systematically evaluate AAII’s acute and chronic toxicity, carcinogenic mechanisms, and environmental exposure patterns using integrated murine models and phytochemical analyses to clarify its toxicological profile and associated health risks. Methods: C57BL/6J mice were used in the following experiments: (1) determination of AAII content in 3 commonly used Aristolochia medicinal materials via liquid chromatography-mass spectrometry/mass spectrometry; (2) acute toxicity testing with single doses of 10, 20, or 40 mg/kg; and (3) chronic exposure with 1 or 10 mg/kg administered every other day for 24 weeks, followed by 21 to 40 weeks of postexposure monitoring. Histopathological examination, whole-exome sequencing, biochemical assays, and micronucleus tests were performed to assess multi-organ damage, tumorigenesis, genomic mutation signatures, and direct clastogenicity. Phytochemical analyses were used to evaluate environmental distribution. Results: (1) A single 40 mg/kg dose of AAII induced dose-dependent renal tubular degeneration without hepatotoxicity; (2) the 10 mg/kg group showed significant mortality (20%), tumor incidence (33.3%, primarily forestomach and bladder transitional cell carcinomas), persistent renal interstitial fibrosis, and subclinical hepatic injury. Chronic exposure to 1 mg/kg still induced 13.3% mortality and 15.5% tumor incidence over a 64-week period; (3) whole-exome sequencing revealed a predominance of C>T mutations and pathway enrichment in chemical carcinogenesis and cytochrome P450-mediated metabolism, indicating reactive metabolite-driven mechanisms distinct from classical AA-DNA adducts; and (4) no histopathological changes were observed in nontarget organs (brain, heart, and testes), and micronucleus assays confirmed the absence of direct clastogenicity. Conclusion: This study highlights the delayed carcinogenic risks of low-dose chronic AAII exposure and emphasizes the need to update regulatory frameworks to ensure the safe use of aristolochiaceae-containing herbal products.

This study investigated the infection status,drug resistance,and molecular characteristics of Shiga toxin-producing Escherichia coli(STEC)in domestic goats in Chengkou county,Chongqing.In August 2023,283 fecal samples were collected from households in Chengkou county.After enrichment with EC broth and inoculation onto selective media,samples that tested positive for stx1/stx2 were selected for further isolation.The positive strains were investigated with antimicrobial susceptibility testing and whole genome sequencing.According to the whole genomic sequences,the stx subtypes,serotypes,multi-locus sequence types,virulence genes,drug resistance genes,and phylogenetic relationships of the STEC strains were analyzed.Forty-six strains of STEC were isolated from 283 goat fecal samples,thus resulting in a detection rate of 16.25%.The 46 STEC strains were categorized into 12 O∶H serotypes,among which O76∶H19 and O8∶H7 predominated,each represented by 9 strains.Five STEC strains were identified as serotype O157∶H7.The 46 STEC strains were categorized into 11 sequence types(STs),among which ST675 and ST196 predominated,each represented by nine strains,accounting for a 19.57%proportion.The strains were categorized into 7 stx subtypes,among which stx1c(26/46,56.52%),followed by stx2k(9/46,19.57%)predominated.All nine Stx2k-STEC strains were identified as serotype O8∶H7 and sequence type ST196.In antimicrobial susceptibility testing,2 STEC strains were resistant to ampicillin,one strain was resistant to ampicillin/sulbactam,one strain was resistant to cefazolin,and one strain was resistant to cefoxitin.Nine Stx2k-STEC strains were found to carry the beta-lactam resistance gene blaEC-18.Antimicrobial sensitivity tests revealed that the nine Stx2k-STEC strains were sensitive to all 15 tested antibiotics.Moreover,phylogenetic analysis indicated that the 9 Stx2k-STEC strains were remarkably similar but showed high genetic diversity with respect to that of the Stx2k-STEC strains isolated from other regions in China.Goatsare an important animal reservoir for STEC in theChengkou district of Chongqing,and novel sequence type Stx2k-STEC strains distinct from those found in other regions of China were identified in this region.