ObjectiveTo explore the effect of oral sodium butyrate on skeletal muscle atrophy in CT26 tumor mice through the gut microbiota-skeletal muscle axis and its potential mechanism. MethodsSixty SPF BALB/c male mice aged 8 weeks were randomly divided into a normal control group (NC, n=18) and a ABX-depleted group (ABX, n=42). The ABX mice were pretreated with a quadruple antibiotic cocktail via oral gavage (0.2 ml per administration, once daily, 6 d per week, for 2 weeks), whereas NC received an equal volume of sterile water. The quadruple antibiotic cocktail consisted of metronidazole (1 g/L), vancomycin (0.5 g/L), ampicillin (1 g/L), and gentamicin (1 g/L). Following successful pretreatment, six mice from each group were randomly selected for gut microbiota sequencing analysis and designated as the Abx group and the NC0 group, respectively. Theremaining mice in ABX were subcutaneously inoculated in the dorsum with 0.2 ml of CT26 cell suspension (at a cell density of 1×10⁷/ml). Then these mice were randomly allocated into three subgroups: a control tumor bearing model group (0_NaB, n=12), a tumor-bearing model group receiving low-dose oral sodium butyrate (L_NaB, n=12), a tumor-bearing model group receiving high-dose oral sodium butyrate (H_NaB, n=12). And mice in NC were inoculated at the same site with 0.2 ml of normal saline. The administration dose for L_NaB was 0.3 g/(kg·d), that for H_NaB was 0.5 g/(kg·d), while NC and 0_NaB were given the same volume of normal saline (0.2ml per time, once daily, 6 d per week, for 4 weeks). The general condition of mice was monitored, and forelimb grip strength gastrocnemius muscle mass and its muscle fiber cross-sectional area were measured for each group. The structural changes in gut microbiota were assessed by 16S rRNA sequencing of cecal contents. Pathological alterations in the intestinal wall were examined via HE staining. Serum and gastrocnemius muscle levels of TNF‑α, IL-6, IL-1β, and LPS were quantified using ELISA. The protein expression of ZO-1 and occludin in the small intestine, as well as proteins associated with the TLR4/MyD88/NF-κB signaling pathway in the gastrocnemius muscle, were detected by Western blot analysis. Results(1) The alpha-diversity in Abx was significantly lower than that in NC0 (P<0.01), a significant decrease of the mass and muscle fiber cross-sectional area of the gastrocnemius (P<0.01), with the majority of gut microbiota being effectively depleted. (2) Compared with NC, the subcutaneous tumors of mice in 0_NaB were prominent, a significant increase of the mass and muscle fiber cross-sectional area of the gastrocnemius, accompanied by a significant decrease in body weight at the end of the 3th and 4th week (P<0.05), and a significant weakening of the forelimb grasping strength at the 5th and 6th week (P<0.01). Compared with 0_NaB, the tumor mass of mice in L_NaB and H_NaB showed a significant decreasing trend, and the grip strength of the forelimbs significantly increased at the 5th and 6th week (P<0.05, P<0.01). (3) Compared with 0_NaB, the Shannon and Observed species indices in α diversity of L_NaB and H_NaB were significantly increased (P<0.05). At the genus level, compared with 0_NaB, L_NaB exhibited a significant decrease in the relative abundance of Parasutterella (P< 0.01), while H_NaB showed significant reductions in the relative abundances of both Escherichia-Shigella and Parasutterella (P < 0.01). (4) Compared with 0_NaB, the small intestinal tissue structure in L_NaB and H_NaB was more intact, the infiltration of inflammatory cells was significantly reduced, and the capillaries were slightly dilated. The expression levels of ZO-1 and occludin proteins in L_NaB were significantly increased (P<0.01). (5) The LPS concentration in the gastrocnemius muscle and the protein expression levels of TLR4, MyD88, p-IκBα, and p-NF‑κB p65 in L_NaB and H_NaB were significantly lower than those in 0_NaB (P<0.05). The serum TNF‑α concentration in H_NaB and TNF-α concentration in the gastrocnemius muscle of the L_NaB and H_NaB were significantly lower than those in 0_NaB (P<0.05, P<0.01, P<0.01). ConclusionOral administration of NaB can improve gut microbiota α diversity, adjusting its composition, improving intestinal mucosal barrier function, reducing the LPS-induced pro-inflammatory response, and delaying skeletal muscle atrophy. The underlying mechanism may involve down regulation of TLR4/MyD88/NF-κB signaling in skeletal muscle.

ObjectiveTo investigate the accuracy of multiple discriminant analysis （MDA） versus fibrosis-4 （FIB-4） in assessing liver fibrosis degree in patients with HBV infection， as well as the possibility of MDA as an indicator for disease progression. MethodsA total of 263 patients with HBV infection who underwent liver biopsy in The First Affiliated Hospital of Guangxi Medical University from April 2010 to April 2024 were included， and their clinical data were collected. According to the results of pathological examination， they were divided into non-significant fibrosis group （F<2） with 126 patients and significant fibrosis group （F≥2） with 137 patients. The correlation of MDA and FIB-4 with liver fibrosis degree was analyzed， and MDA and FIB-4 were compared in terms of their accuracy in assessing significant liver fibrosis. A total of 62 patients completed follow-up， and according to the presence or absence of progression to liver cirrhosis at the last follow-up visit， they were divided into progressive group with 21 patients and non-progressive group with 41 patients； the efficacy of MDA and FIB-4 in diagnosing disease progression was analyzed and compared. The independent-samples t test was used for comparison of normally distributed continuous data between groups， and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between groups； the Kruskal-Wallis H test was used for comparison between multiple groups， and the Bonferroni method was used for further comparison between two groups. The chi-square test was used for comparison of categorical data. The Spearman’s correlation coefficient was used for correlation analysis. The Wilcoxon signed rank sum test was used for the analysis of baseline data and data at the end of follow-up， and the binary Logistic regression analysis was used to investigate the influencing factors for progression to liver cirrhosis. The receiver operating characteristic （ROC） curve was used to investigate the diagnostic efficacy of indicators， the Z-test was used for comparison of the area under the ROC curve （AUC）， and the paired chi-square test was used for comparison of the sensitivity， specificity， and accuracy of the two indicators. ResultsThe correlation coefficient between FIB-4 and liver fibrosis degree was 0.378， while the correlation coefficient between MDA and liver fibrosis degree was -0.325 （both P<0.001）. FIB-4 had an AUC of 0.688， a sensitivity of 64.96%， a specificity of 68.87%， a positive predictive value of 67.42%， a negative predictive value of 63.36%， an accuracy of 65.40%， and a cut-off value of 1.01， while MDA had an AUC of 0.653， a sensitivity of 52.55%， a specificity of 78.57%， a positive predictive value of 72.73%， a negative predictive value of 60.37%， an accuracy of 65.02%， and a cut-off value of 0.29， suggesting that compared with FIB-4， MDA had a lower sensitivity （P=0.004） and a higher specificity （P=0.001）. The progressive group had a significantly higher age than the non-progressive group at baseline （t=2.611， P=0.011）. For the progressive group， there was an increase in FIB-4 and a reduction in MDA from baseline to the end of follow-up （both P<0.001）， while the non-progressive group showed no significant changes （both P>0.05）. The multivariate Logistic regression analysis showed that aspartate aminotransferase （odds ratio ［OR］=0.940， 95% confidence interval ［CI］： 0.885‍ ‍—‍ ‍0.998， P<0.05） and MDA （OR=0.445， 95%CI： 0.279‍ ‍—‍ ‍0.710， P<0.001） were independent influencing factors for disease progression. MDA had an AUC of 0.893 and an optimal cut-off value of -0.01 in diagnosing the disease progression of liver cirrhosis. ConclusionMDA has a comparable accuracy to FIB-4 in the diagnosis of significant liver fibrosis， and MDA<-0.01 has a high accuracy in diagnosing the progression of liver fibrosis to liver cirrhosis， which can help to reduce the need for liver biopsy in clinical practice.

Objective Prepubertal mice are administered subcutaneously with letrozole sustained-release pellets behind the neck and treated with a high-fat diet to establish a mouse model of polycystic ovary syndrome(PCOS).The liver transcriptomes of the model mice are compared with those of the placebo control mice to investigate the underlying mechanisms of liver involvement in the pathogenesis of PCOS.Methods A customized 2 mg dose of letrozole sustained-release pellets with a 40-day release period was used.The control placebo and letrozole pellets were implanted subcutaneously in the dorsal cervical region of 3-4-week-old C57BL/6J mice(8 mice per group)to establish the control group and letrozole-induced PCOS model group.Both groups were treated with a high-fat diet starting the day after administration.The modeling period lasted for 5 weeks,during which body weight and 24-hour food intake were monitored in each group every week.When samples were collected,liver weight was recorded.Pathological changes in ovarian and hepatic tissues were examined by hematoxylin-eosin(HE)staining,while hepatic lipid deposition was observed by Oil Red O staining.The extent of macrophage infiltration in the liver was evaluated via F4/80 immunohistochemical staining,and hepatic fibrosis levels were observed by Masson's trichrome staining.Transcriptomic sequencing was performed to analyze differentially expressed genes(DEGs)in liver tissues between the control and model groups,followed by enrichment analysis of significant DEGs.Quantitative real-time fluorescent quantitative PCR(qPCR)was subsequently used to validate the expression of significant DEGs in liver tissues of both groups.Results Compared with the control group,the model group which received subcutaneous letrozole sustained-release pellets combined with a high-fat diet exhibited significantly increased body weight(P＜0.001),prominent polycystic ovarian morphology,and significantly decreased liver-to-body weight ratio(P＜0.05).However,no significant changes were observed in absolute liver weight(P＞0.05),hepatic histomorphology,or lipid deposition.Transcriptome sequencing identified 119 upregulated and 217 downregulated DEGs in the liver tissues of letrozole-treated mice,which were predominantly enriched in pathways related to cholesterol and steroid biosynthesis,steroid hormone metabolism,and inflammatory responses.qPCR validation demonstrated that mRNA expression of HSD3B2 and HMGCR was significantly upregulated in liver(P＜0.01),while mRNA expression of IL4,CCL2 and COL1A1 was downregulated(P＜0.05)in the model group compared with the control group.However,Masson's trichrome staining and F4/80 immunohistochemical analysis showed no significant changes in hepatic fibrosis or macrophage infiltration.Conclusion Subcutaneous administration of letrozole sustained-release pellets combined with a high-fat diet successfully establishes a mouse model of PCOS.The model mice exhibited significant changes in hepatic gene expression.Liver may contribute to PCOS pathogenesis through regulating cholesterol and steroid metabolism.

Purpose To investigate the predictive value of placental microflow combined with serum cystatin C(Cys C)for late-onset preeclampsia(LOP).Materials and Methods This was a prospective study including 188 singleton pregnant women who underwent prenatal ultrasound examination and delivered in the First Affiliated Hospital,School of Medicine,Shihezi University from October 2021 to October 2022.The placental microvascular indexes,including vascularization index,flow index and vascularization-flow index(VFI),were detected by three-dimensional power Doppler ultrasound in the second trimester,and the serum Cys C level was detected.The pregnancy outcome of the pregnant women was divided into LOP group and normal group(NLOP group),and the predictive value of placental microflow combined with serum Cys C for LOP was analyzed.Results Placental vascularization index and VFI of the LOP group were lower than those of the NLOP group(29.77±11.97 vs.44.44±9.86,9.23±3.51 vs.15.05±4.38).However,serum Cys C in the LOP group was higher than that in the NLOP group[(1.13±0.17)mg/L vs.(0.84±0.18)mg/L],and the differences were statistically significant(t=-3.616,-4.790,4.682,all P<0.05).The area under the curve of placental VFI combined with serum Cys C for predicting LOP was 0.899,which had the highest predictive value.Conclusion Placental VFI combined with serum Cys C detection can help to improve the prediction efficiency of LOP,and it is better than each single item.

Objective:To investigate the difference of Roussouly ideal classification in predicting postoperative proximal junctional kyphosis (PJK) between adult degenerative spinal deformity patients with and without pelvic fixation and the potential reasons.Methods:From January 2017 to January 2020, a total of 95 patients (4 males, 91 females; with an average age of 62.03±6.30 years) with degenerative spinal deformities were retrospectively analyzed. There were 35 patients in the non-pelvic group (1 male, 34 females) and 60 patients in the pelvic group (3 males, 57 females). The radiographic parameters included coronal Cobb's angle (CA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), T1 pelvic angle (TPA), and proximal junctional angle (PJA) were measured in the standing radiographs preoperatively, postoperatively at 2 weeks, and 2-year follow-up. Changes in PT and SS were calculated for patients at 2 weeks and the 2-year follow-up. Based on the revised Roussouly classification, 95 patients were classified into different types preoperatively, postoperatively at 2 weeks, and during the 2-year follow-up. Changes in the classification of patients were documented postoperatively at 2 weeks. Roussouly types were determined using preoperative pelvic parameters, and a match was defined when the 2-week postoperative classification aligned with the ideal type. The occurrence of PJK and the relationship with classification matching were recorded in the group. Independent t-tests were used for intergroup comparisons of radiographic parameters, and chi-square tests were employed to assess classification changes and predictive accuracy of the Roussouly classification. Results:Preoperative PT, TPA and SVA in non-pelvic group were significantly smaller than those in pelvic group, and preoperative SS and LL larger than those in pelvic group ( P<0.05). The changes of PT and SS in non-pelvic group were significantly lower than those in pelvic group 2 weeks after surgery ( P<0.05). The proportion of classification changes in the pelvic group was significantly higher than that in the non-pelvic group (60% vs. 34%, χ 2=5.847, P=0.016). Among the 95 patients, a total of 29 experienced PJK during the follow-up, with 3 cases progressing to PJF. The incidence of PJK in mismatched patients was 37% with no significant difference compared with matched patients (19%) (χ 2=3.357, P=0.067). In the sacral spine group of 60 patients, 22 experienced PJK, with 3 cases progressing to PJF. Among them, 19 patients with PJK had a classification mismatch with the ideal classification at 2 weeks postoperatively. The PJK incidence was significantly higher in mismatched patients (45%) compared to matched patients (17%) (χ 2=4.429, P=0.035). In the non-pelvic group, 7 patients developed PJK, with 3 mismatched cases. The PJK incidence in mismatched vs. matched patients was 18% vs. 22%, showing no significant difference (χ 2=0.114, P=0.735). Conclusions:For the patients with degenerative spinal deformity, pelvic fixation leads to a more complete restoration of the ideal Roussouly classification. Restoration of the Roussouly type in patients with pelvic fixation is a reliable predictor of postoperative PJK. However, in patients without pelvic fixation, the alignment with the ideal Roussouly classification does not significantly correlate with PJK development.

Objective:To explore the composition of gut microbiome, the characteristics of virulence factor genes and their relationship with liver metabolic inflammation in overweight or obese children.Methods:A case-control design was conducted. From the children who visited the West China Second University Hospital of Sichuan University for medical or physical examinations between August 2021 and April 2022, a total of 23 obese children (obesity group), 8 overweight children (overweight group), and 22 healthy children (control group) were recruited. The body mass index of children was calculated after anthropometric measurements; metabolic inflammation indexes such as the levels of fasting blood glucose and hepatic function and renal function etc. were detected. The composition and abundance of gut microbiota in the feces of the children were detected by metagenomic sequencing technology and the Shannon index and Simpson index were calculated to assess the α diversity of virulence factor genes. The Wilcoxon rank-sum test was used for pairwise comparison between groups. The Spearman′s rank correlation test was used for correlation analysis, and the Benjamini-Hochberg method was used to correct the P-value of multiple tests. Results:The obese group included 23 children aged 8.5 (6.3, 11.8) years, of whom 9 (39%) were male. The overweight group consisted of 8 children aged 9.2 (5.5, 12.3) years, of whom 4 were male. The control group comprised 22 children aged 5.3 (5.1, 5.4) years, of whom 10 (45%) were male. The obese group exhibited higher levels of alanine aminotransferase (ALT), gamma-glutamyl transferase (γ-GT), globulin, and uric acid compared to those of the control group (all P<0.05), with ALT also higher than that of the overweight group ( P<0.05). The levels of fasting blood glucose, γ-GT, globulin, and uric acid in the overweight group were all higher than those in the control group (all P<0.05). The abundance of Coprococcus A (0.76 (0.00, 3.11) vs. 0.00 (0.00, 0.00), false discovery rate ( FDR)<0.05) and Parasutterella (0.89 (0.08, 1.79) vs. 0.00 (0.00, 0.08), FDR<0.05) in the gut of children in the obese group were both higher than those of the control group. The number of virulence factor genes in the obese group was higher than those of the control group (941 (886, 977) vs. 890 (807, 920), P<0.05). The Simpson index and Shannon index of gut microbial virulence factor genes in the obese group were both higher than those of the control group (0.993 (0.992, 0.993) vs. 0.991(0.990, 0.991), (5.50 (5.46, 5.56) vs. 5.37 (5.30, 5.43), both P<0.01). The abundance of gut microbiota virulence factors genes all showed positive correlations with fasting blood glucose, ALT, γ-GT, and uric acid levels in children (all r>0.3, all FDR<0.05). The abundance of 17 gut microbial virulence factor genes were all positively associated with γ-GT levels (all r>0.3, all FDR<0.05). The virulence factor genes (LpxH, LpxB, LpxK) of lipopolysaccharide were all positively correlated with plasma γ-GT and globulin levels (all r>0.3, all FDR<0.05). Conclusions:Overweight or obese children exhibited elevated liver metabolic-inflammatory markers compared to their normal-weight counterparts. Notably, obese children demonstrated gut microbiota dysbiosis accompanied by enrichment of virulence factor genes, which may promote liver metabolic inflammation through pathways such as lipopolysaccharide biosynthesis.

With the rapid development of generative artificial intelligence(GAI)technologies,their widespread application in academic research and writing is continuously expanding the boundaries of sci-entific inquiry.However,this trend has also raised a series of ethical and regulatory challenges,inclu-ding issues related to authorship,content authenticity,citation accuracy,and accountability.In light of the growing involvement of AI in generating academic content,establishing an open,controllable,and trustworthy ethical governance framework has become a key task for safeguarding research integrity and maintaining trust within the academic community.This expert consensus outlines ethical requirements across key stages of AI-assisted academic writing-including topic selection,data management,citation practices,and authorship attribution.It aims to clarify the boundaries and ethical obligations surrounding AI use in academic writing,ensuring that technological tools enhance efficiency without compromising in-tegrity.The goal is to provide guidance and institutional support for building a responsible and sustainable research ecosystem.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

Objective:To investigate the difference of Roussouly ideal classification in predicting postoperative proximal junctional kyphosis (PJK) between adult degenerative spinal deformity patients with and without pelvic fixation and the potential reasons.Methods:From January 2017 to January 2020, a total of 95 patients (4 males, 91 females; with an average age of 62.03±6.30 years) with degenerative spinal deformities were retrospectively analyzed. There were 35 patients in the non-pelvic group (1 male, 34 females) and 60 patients in the pelvic group (3 males, 57 females). The radiographic parameters included coronal Cobb's angle (CA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), T1 pelvic angle (TPA), and proximal junctional angle (PJA) were measured in the standing radiographs preoperatively, postoperatively at 2 weeks, and 2-year follow-up. Changes in PT and SS were calculated for patients at 2 weeks and the 2-year follow-up. Based on the revised Roussouly classification, 95 patients were classified into different types preoperatively, postoperatively at 2 weeks, and during the 2-year follow-up. Changes in the classification of patients were documented postoperatively at 2 weeks. Roussouly types were determined using preoperative pelvic parameters, and a match was defined when the 2-week postoperative classification aligned with the ideal type. The occurrence of PJK and the relationship with classification matching were recorded in the group. Independent t-tests were used for intergroup comparisons of radiographic parameters, and chi-square tests were employed to assess classification changes and predictive accuracy of the Roussouly classification. Results:Preoperative PT, TPA and SVA in non-pelvic group were significantly smaller than those in pelvic group, and preoperative SS and LL larger than those in pelvic group ( P<0.05). The changes of PT and SS in non-pelvic group were significantly lower than those in pelvic group 2 weeks after surgery ( P<0.05). The proportion of classification changes in the pelvic group was significantly higher than that in the non-pelvic group (60% vs. 34%, χ 2=5.847, P=0.016). Among the 95 patients, a total of 29 experienced PJK during the follow-up, with 3 cases progressing to PJF. The incidence of PJK in mismatched patients was 37% with no significant difference compared with matched patients (19%) (χ 2=3.357, P=0.067). In the sacral spine group of 60 patients, 22 experienced PJK, with 3 cases progressing to PJF. Among them, 19 patients with PJK had a classification mismatch with the ideal classification at 2 weeks postoperatively. The PJK incidence was significantly higher in mismatched patients (45%) compared to matched patients (17%) (χ 2=4.429, P=0.035). In the non-pelvic group, 7 patients developed PJK, with 3 mismatched cases. The PJK incidence in mismatched vs. matched patients was 18% vs. 22%, showing no significant difference (χ 2=0.114, P=0.735). Conclusions:For the patients with degenerative spinal deformity, pelvic fixation leads to a more complete restoration of the ideal Roussouly classification. Restoration of the Roussouly type in patients with pelvic fixation is a reliable predictor of postoperative PJK. However, in patients without pelvic fixation, the alignment with the ideal Roussouly classification does not significantly correlate with PJK development.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.