1.Xiaoyao Shukun Decoction Treats Sequelae of Pelvic Inflammatory Disease by Regulating Neutrophil Extracellular Traps via PI3K/Akt/mTOR Pathway
Jing PAN ; Bing ZHANG ; Chunxiao DANG ; Jinxiao LI ; Pengfei LIU ; Xiao YU ; Yuchao WANG ; Jinxing LIU
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(15):69-78
ObjectiveTo investigate how Xiaoyao Shukun decoction (XYSKD) regulates the formation and release of neutrophil extracellular traps (NETs) via the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway, thereby reducing inflammation, inhibiting the excessive proliferation of fibroblasts in pelvic adhesion tissue, decreasing adhesion and fibrosis, and repairing the tissue damage in sequelae of pelvic inflammatory disease (SPID). MethodsA total of 84 Wistar rats were randomly allocated into seven groups: blank, model, XYSKD (8 mg·kg-1), mTOR agonist (10 mg·kg-1), mTOR agonist + XYSKD (10 mg·kg-1+8 mg·kg-1), mTOR inhibitor (2 mg·kg-1), and mTOR inhibitor + XYSKD (2 mg·kg-1+8 mg·kg-1). The rat model of SPID was constructed by starvation, fatigue, and ascending Escherichia coli infection. After 14 days of drug intervention, the ultrastructure of fibroblasts in the pelvic adhesion tissue was observed by transmission electron microscopy. The general morphology of the uterus, fallopian tube, and ovary was observed by laparotomy. The levels of interleukin-1β (IL-1β), interleukin-17 (IL-17), and tumor necrosis factor-α (TNF-α) in the peritoneal flushing fluid were determined by enzyme-linked immunosorbent assay (ELISA). The expression of myeloperoxidase (MPO) and citrullinated histone 3 (H3) in the fallopian tube was detected by immunofluorescence. Western blot and Real-time quantitative polymerase chain reaction (Real-time PCR) were employed to determine the relative protein and mRNA levels, respectively, of neutrophil elastase (NE), intercellular adhesion molecule-1 (CD54), α-smooth muscle actin (α-SMA), H3, PI3K, and Akt. ResultsCompared with the blank group, the model group presented a large number of collagen fibers in bundles, numerous cytoplasmic folds of fibroblasts, reduced or absent mitochondrial cristae, and disordered and expanded endoplasmic reticulum. By laparotomy, extensive pelvic congestion, connective tissue hyperplasia, thickening and hardening of the tubal end near the uterus, and tubal and ovarian adhesion or cyst were observed in the model group. In addition, the model group showed raised levels of IL-1β, IL-17, and TNF-α in the peritoneal flushing fluid (P<0.01), increased average fluorescence intensities of MPO and H3 (P<0.01), and up-regulated protein and mRNA levels of NE, H3, CD54, PI3K, and Akt (P<0.01). Compared with the model group, the mTOR agonist group showed increased fibroblasts and cytoplasmic folds, absence of mitochondrial cristae, endoplasmic reticulum dilation, and evident collagen fiber hyperplasia. Pelvic adhesions were observed to cause aggravated damage to the uterine, fallopian tube, and ovarian tissues. The levels of IL-1β, IL-17, and TNF-α in the peritoneal lavage fluid elevated (P<0.01) and the average fluorescence intensities of MPO and H3 enhanced (P<0.01) in the mTOR agonist group. In contrast, the XYSKD group and the mTOR inhibitor group showcased decreased fibroblasts and collagen fibers, alleviated mitochondrial crista loss and endoplasmic reticulum dilation, improved morphology and appearance of the uterine, fallopian tube, and ovarian tissues, lowered levels of IL-1β, IL-17, and TNF-α in the peritoneal lavage fluid (P<0.01), decreased average fluorescence intensities of MPO and H3 (P<0.01), and down-regulated protein and mRNA levels of NE, H3, CD54, PI3K, and Akt (P<0.05). Compared with the mTOR agonist group, the mTOR agonist + XYSKD group showed alleviated pathological changes in the pelvic tissue, declined levels of IL-1β, IL-17, and TNF-α (P<0.01), decreased average fluorescence intensities of MPO and H3 (P<0.01), and down-regulated protein levels of NE, H3, CD54, α-SMA, p-PI3K/PI3K, and p-Akt/Akt (P<0.01) and mRNA levels of NE, H3, CD54, α-SMA, PI3K, and Akt (P<0.01). Compared with the mTOR inhibitor group, the mTOR inhibitor + XYSKD group demonstrated reduced pathological severity of the pelvic tissue, reduced levels of IL-1β, IL-17, and TNF-α (P<0.01), decreased average fluorescence intensities of MPO and H3 (P<0.01), and down-regulated protein and mRNA levels of NE and CD54 (P<0.05). ConclusionXYSKD can inhibit the excessive formation and release of NETs via PI3K/Akt/mTOR to ameliorate the inflammatory environment and reduce fibrosis and adhesion of the pelvic tissue, thereby playing a role in the treatment of SPID. It may exert the effects by lowering the levels of IL-1β, IL-17, and TNF-α and down-regulating the expression of NE, H3, CD54, α-SMA, PI3K, and Akt in the pelvic adhesion tissue.
2.Delayed physical growth and related factors in pediatric patients with transfusion-dependent thalassemia
Zhexiang KUANG ; Jingyu ZHAO ; Xiao YU ; Jing XU ; Zhen GAO ; Yanjie LIU ; Anni WANG ; Jin DONG ; Hong PAN ; Lele ZHANG ; Liwei FANG ; Guibin WU ; Xinli LI ; Jun SHI ; Li XU ; Wenjun XIE
Chinese Journal of Hematology 2025;46(4):328-335
Objectives:To investigate the physical growth status of pediatric patients with transfusion-dependent thalassemia (TDT) and analyze the effects of treatment-related and socioeconomic factors on physical growth.Methods:Based on the specialized thalassemia database from gene therapy clinical research at the Institute of Hematology & Hospital of Blood Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, we collected data on height and weight development, family economic status, and medical records of 338 pediatric patients with TDT from October 2023 to May 2024. The length/height-for-age and body mass index (BMI) -for-age were classified based on the Growth Standard for Children under 7 Years of Age, Standard for Height Level Classification among Children and Adolescents Aged 7-18 Years, and Dietary Guidelines for Chinese Residents. Logistic regression analysis was conducted to assess the effects of family economic status and disease-related treatment on length/height-for-age and BMI-for-age.Results:Among the 338 patients, 118 were children and 220 were adolescents (192 males and 146 females), with a median age of 12 years (range: 0.8-18) and a median diagnosis duration of 10.3 years (range: 0.5-17.9). Subtypes included α-thalassemia [21 cases (6.2%) ], β-thalassemia [288 cases (85.2%) ], and combined αβ-thalassemia[29 cases (8.6%) ]. The monthly household income of patients was concentrated in 3 000-5 000 yuan (39.9%) and 5 001-10 000 yuan (34.9%), whereas 67.2% of the families had monthly medical expenses of <3 000 yuan. Of the patients, 75.5% received their first transfusion before 1 year of age. The proportions of children and adolescents with pretransfusion hemoglobin (HGB) of ≤70 g/L were 4.2% and 6.4%, respectively. Adolescents demonstrated significantly higher rates of transfusion frequency of <4 weeks/session, monthly red blood cell infusion of >2 U, serum ferritin (SF) of ≥5 000 μg/L, iron chelation therapy, and splenectomy compared with children (all P<0.05). Of the 338 patients, 26.0%, 22.8%, and 8.9% demonstrated stunted growth, underweight, and concurrent stunted growth with underweight, respectively. No significant difference was observed in the stunted growth rates between children (22.9%) and adolescents (27.7%) ( P=0.402). However, the underweight rate in adolescents (26.8%) was significantly higher than that in children (15.3%) ( P=0.023). The multivariate analysis determined the following risk factors for stunted growth: monthly household income of <10 000 yuan (5 001-10 000 yuan: OR=5.49, 95% CI: 1.48-35.76; 3 000-5 000 yuan: OR=6.87, 95% CI: 1.88-44.60; <3 000 yuan: OR=9.29, 95% CI: 2.20-64.77), pretransfusion HGB of ≤70 g/L ( OR=3.25, 95% CI: 1.07-10.18), and SF of ≥5 000 μg/L ( OR = 3.04, 95% CI: 1.20-7.70). Longer diagnostic duration was associated with underweight ( OR=1.10, 95% CI: 1.01-1.20) . Conclusions:Children and adolescents with TDT with pretransfusion SF of ≥5 000 μg/L, HGB of ≤70 g/L, low monthly household income, or longer diagnosis duration were significantly more likely to experience delayed physical growth.
3.ESTABLISHMENT AND APPLICATION OF A MULTIPLEX PCR DETECTION METHOD FOR THREE COMMON PATHOGENS CAUSING DIARRHEA IN YAKS
Yao PAN ; Jing ZHANG ; Mei-Jun JIN ; Ling-Xiang XIN ; Hai-Yue XIAO ; Yan LIU ; Wen-Sheng YAO ; Chuan CHENG ; Li-Li HAO ; Lan LAN ; Liang-Quan ZHU
Acta Parasitologica et Medica Entomologica Sinica 2025;32(3):146-152
Objective To establish a rapid,sensitive,and specific multiplex PCR detection method for the simultaneous detection of Cryptosporidium,Eimeria,and bovine parvovirus.Methods Specific primers targeting the SSU rRNA genes of Cryptosporidium and Eimeria,as well as the VP2 gene of bovine parvovirus were designed and the corresponding recombinant plasmid standards were constructed.To establish the multiplex PCR method,the reaction conditions were optimized using temperature gradient PCR and single-variable control methods.The sensitivity,specificity,reproducibility,and clinical application of the protocol were evaluated.Results The optimal annealing temperature was found to be 60.5℃,and the forward and reverse primer concentrations were determined to be 0.2 μmol/L for Eimeria,and 0.4 μmol/L for Cryptosporidium and bovine parvovirus.The assay demonstrated high sensitivity,with detection limits of 243,260,and 3 110 copies for the recombinant plasmid standards of Cryptosporidium,Eimeria,and bovine parvovirus,respectively.Specificity testing showed no cross-reactivity with ten common bovine pathogens,including Salmonella,bovine viral diarrhea virus,and bovine rotavirus.Consistent intra-and inter-batch results confirmed the strong reproducibility of the method.Clinical application to 81 diarrhea samples from various regions in the Ganzi Prefecture,Sichuan,revealed positivity rates of 18.52%(15/81)for Cryptosporidium,34.57%(28/81)for Eimeria,and 18.52%(15/81)forbovineparvovirus,withamixedinfectionrateof3.7%(3/81).Conclusions Themultiplex PCR method established in this study offers a reliable tool for differential diagnosis and epidemiological investigation of the three common diarrheal pathogens in yaks.
4.Global regulatory requirement and considerations for pharmaceutical co-crystals
Jing PAN ; Xiao-yan WANG ; Xiao-long HUANG
The Chinese Journal of Clinical Pharmacology 2025;41(2):296-300
As a new solid-state form of drugs,pharmaceutical co-crystals can improve the physicochemical properties of drugs(such as melting point,stability,solubility,hygroscopicity,compressibility,permeability,bioavailability,etc),thereby changing drug performance or enhancing therapeutic efficacy,providing new ideas for drug development.In recent years,pharmaceutical co-crystals has attracted much attention as a hot topic in the research of crystalline drugs,but there is currently no specialized guiding principle for pharmaceutical co-crystals research in China.This article mainly investigates the technical documents on pharmaceutical co-crystals research released by the Food and Drug Administration(FDA)and the European Medicines Agency(EMA),elaborates on the regulatory requirements for pharmaceutical co-crystals in foreign countries,compares and analyzes the regulatory requirements of FDA and EMA,in order to provide references for the research and regulation of pharmaceutical co-crystals in China.
5.A study on community healthcare workers preferences for providing Traditional Chinese Medicine health management services based on Discrete Choice Experiment
Xiao-jing MA ; Hang XU ; Yu-na PAN ; Jian-ping REN
Chinese Journal of Health Policy 2025;18(3):48-56
Objective:To investigate the preferences and influencing factors of Traditional Chinese Medicine(TCM)health management services among community healthcare workers,providing a reference for promoting and spreading TCM health management services in communities.Methods:Based on a discrete choice experiment,a questionnaire survey was conducted among 596 community healthcare workers across 9 administrative districts in Beijing.A mixed logit model was used to analyze their preferences.Results:Changes in post-tax monthly income,expected efficacy,single-service duration,technical difficulty,patient compliance,and insurance coverage significantly influenced community doctors'service preferences.Changes in post-tax monthly income had the highest relative importance(35.11%),followed by insurance coverage(34.87%).Preferences varied among healthcare workers with different professional titles,backgrounds,weekly working hours,and whether the service was included in performance evaluations.Conclusion:Both economic and non-economic factors influence community healthcare workers'service preferences to varying degrees.Optimizing the combination of TCM health management service attributes can enhance community healthcare workers'willingness to provide such services.It is recommended to use a combination of economic and non-economic incentive measures and develop differentiated strategies for healthcare workers with different characteristics to meet their service preferences and promote the development of TCM health management services in communities.
6.Disease burden and trends in enteric infections in China,1990-2021:a One Health perspective
Jing TAN ; Fei WANG ; Shi-pan CHEN ; Xiao-chun LI ; Hong-xin JU ; Chun-xiao YANG ; Wen-qiang YIN ; Lan-hua LI
Chinese Journal of Zoonoses 2025;41(5):472-479
This study analyzed the burden and trends in enteric infections in China from 1990 to 2021 from a One Health perspec-tive.Data on mortality associated with enteric infections were extracted from the 2021 Global Burden of Disease(GBD)database.The analysis focused on assessing the mortality rates of enteric infectious diseases attributed to various etiologies and risk factors,along with the age and sex distribution,from 1990 to 2021.Average annual percentage change(AAPC)was used to assess the total changes in disease burden.The age-standardized mortality rate of intestinal infections in China decreased from 9.642/100 000 in 1990 to 0.439/100 000 in 2021,with an AAPC of-57.103%(95%CI:-57.118%to-57.088%).In 2021,Rotavirus,Norovirus,and Crypto-sporidium were the top three etiologies contributing to disease burden,with mortality rates of 1.020/100 000,0.040/100 000 and 0.079/100 000,respectively.A significant variation in etiology distribution was observed across age groups:Rotavirus,Shigella,and Crypto-sporidium dominated among children under 5 years of age,whereas Cryptosporidium,Norovirus,and Clostridioides difficile were more prevalent in older populations.Risk factor analysis indicated that unsafe water sources and poor sanitation accounted for 73.394%of all enteric disease-related deaths.In conclusion,the burden of enteric infections in China markedly declined from 1990 to 2021,and sig-nificant variations in the etiological spectrum and disease burden were observed across age groups.The persistent effects of unsafe wa-ter sources and poor sanitation underscore the need for targeted interventions to further decrease the burden of these diseases.Our find-ings highlight the success of public health interventions in decreasing the burden of enteric infections in China,while emphasizing the need for targeted measures to address disparities in high-risk populations and improve environmental sanitation.
7.Antimicrobial resistance surveillance in the bacterial strains isolated from pediatric intensive care units in China:results from 2020 to 2022
Jing LIU ; Huiyuan YAN ; Gangfeng YAN ; Guoping LU ; Pan FU ; Chuanqing WANG ; Danqun JIN ; Wenjia TONG ; Chenyu ZHANG ; Jianli CHEN ; Yi LIN ; Jia LEI ; Yibing CHENG ; Qunqun ZHANG ; Kaijie GAO ; Yuanyuan CHEN ; Shufang XIAO ; Juan HE ; Li JIANG ; Huimin XU ; Yuxia LI ; Hanghai DING ; Hehe CHEN ; Yao ZHENG ; Qunying CHEN ; Ying WANG ; Hong REN ; Chenmei ZHANG ; Zhenjie CHEN ; Mingming ZHOU ; Yucai ZHANG ; Yiping ZHOU ; Zhenjiang BAI ; Saihu HUANG ; Lili HUANG ; Weiguo YANG ; Weike MA ; Qing MENG ; Pengwei ZHU ; Yong LI ; Yan XU ; Yi WANG ; Yanqiang DU ; Huijun CAI ; Bizhen ZHU ; Huixuan SHI ; Shaoxian HONG ; Yukun HUANG ; Meilian HUANG
Chinese Journal of Infection and Chemotherapy 2025;25(3):303-311
Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2%)and gram-negative organisms(60.8%).The top three organisms were S.aureus(13.6%,1 453/10 688),A.baumannii(10.0%,1 067/10 688),and coagulase-negative Staphylococcus(9.9%,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1%,19.4%,8.8%,30.9%,67.4%,and 28.8%,respectively.Overall,more than 50%of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25%of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80%of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3%in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.
8.Study on the Correlation between Palm Temperature,Disease Activity,and Traditional Chinese Medicine Syndrome Types in Patients with Rheumatoid Arthritis
Xiao-shuang HOU ; Li-min PAN ; Chen-jing GAO ; Ya-ping LUO
Progress in Modern Biomedicine 2025;25(9):1517-1524,1548
Objective:To explore the correlation between palm temperature,disease activity,and traditional chinese medicine syndrome types in patients with rheumatoid arthritis(RA).Methods:80 RA patients(RA group)who were admitted to our hospital from April 2022 to June 2024 were selected,they were divided into high group(DAS28 score>5.1 score)and low to moderate group(2.6 score ≤ DAS28 score≤5.1 score)according to the 28 joint disease activity scores(DAS28).70 healthy volunteers who underwent physical examinations during the same period(control group)were selected.The palm temperature,erythrocyte sedimentation rate(ESR),C-reactive protein(CRP),and DAS28 scores between the control group and RA group were compared.The palm temperature,ESR,and CRP levels between low to moderate group and high group were compared.The correlation between palm temperature and disease activity,ESR,and CRP levels in RA patients was analyzed by Pearson correlation.The distribution of traditional chinese medicine syndrome types in RA patients was observed,the palm temperature,ESR,and CRP levels of RA patients with different traditional chinese medicine syndrome types were compared.Results:The palm temperature,ESR,CRP levels,and DAS28 score in the RA group were higher than those in the control group(P<0.05).The palm temperature,ESR,and CRP levels in the high group were higher than those in the low to moderate group(P<0.05).Pearson correlation analysis results showed that,the palm temperature of RA patients was positively correlated with DAS28 score,ESR,and CRP levels(P<0.05).Among 80 RA patients,there were 17 cases(21.25%)of liver and kidney deficiency syndrome,23 cases(29.02%)of cold and dampness obstruction syndrome,14 cases(17.86%)of qi and blood deficiency syndrome,17 cases(21.47%)of damp heat obstruction syndrome,and 9 cases(11.52%)of phlegm and blood stasis obstruction syndrome.The palm temperature,ESR,and CRP levels of patients with Qi and blood deficiency syndrome,liver and kidney deficiency syndrome,and phlegm and blood stasis obstruction syndrome increased in sequence and were higher than those of patients with damp heat obstruction syndrome and cold and dampness obstruction syndrome(P<0.05).There was no statistical difference in palm temperature,ESR,and CRP levels between the groups of damp heat obstruction syndrome and cold and dampness obstruction syndrome(P>0.05).Conclusion:There is a certain correlation between the palm temperature and disease activity and traditional chinese medicine syndrome types of RA patients.Regular observation of palm temperature,ESR,CRP levels,and DAS28 score is helpful for assessing the condition of RA patients.
9.Experimental study on alternative method of local lymph node assay using bromodeoxyuridine with flow cytometry(LLNA:BrdU-FCM)for skin sensitization evaluation of cosmetics
Xiao-jun LYU ; Ju ZHANG ; Sen WU ; Xiao-ling XU ; Meng-ting SHI ; Jin-jing XU ; Wang-ping PAN ; Jia-te SHEN ; Kai-yong HE
Chinese Pharmacological Bulletin 2025;41(4):793-799
Aim To establish and evaluate an alternative meth-od for detecting skin sensitization of cosmetics based on local lymph node assay using bromodeoxyuridine(BrdU)with flow cytometry(FCM).Methods(1)25%hexyl cinnamic alde-hyde(HCA)was chosen as a positive control with an acetone:olive oil(4∶1,V/V,AOO)mixture as a vehicle control for the experiment.The dorsal sides of both ears of mice were treated with test solutions on day 1,day 2,and day 3.Brdu solution was injected inter-peritoneally on day 5.On day 6,the bilateral ears and mandibular lymph nodes were excised,and the number of Brdu positive cells was measured by flow cytometry.The stim-ulation index(SI)was calculated to identify whether it was ≥3,in order to establish the method of LLNA:Brdu-FCM.(2)BrdU-FCM test was conducted using a blind method with the fif-teen reference substances listed in OECD TG429 whose skin sensitization potentials were known.The test substances were dissolved in AOO,N,N-dimethylformamide(DMF)or dimeth-yl sulfoxide(DMSO)at three different concentrations.Tests were performed the same as above.SI and EC2.7 were calculat-ed to evaluate whether the test substance was categorized as a skin sensitizer.The reliability and accuracy of the method were validated by comparing the classification of test substances with that in OECD TG429.Results The SI for 25%HCA was 3.9,showing positive in the skin sensitization test.It demonstrated that the LLNA:Brdu-FCM test method was properly implemen-ted.Nine test substances(2,4-dinitrochlorobenzene,4-pheny-lenediamine,cobalt chloride,2-mercaptobenzothiazole,hexyl-cinnamaldehyde,eugenol,phenyl benzoate,cinnamic alcohol,imidazolidinyl urea)were positive,and six test substances(methyl methacrylate,chlorobenzene,isopropanol,lactic acid,methyl salicylate,salicylic acid)were negative.The method was evaluated with sensitivity of 90%,specificity of 100%,positive prediction rate of 100%,negative prediction rate of 83%,false positive rate of 0%,false negative rate of 17%and accuracy of 93%.The LLNA:BrdU-FCM assay could correctly categorize the test substances that were skin sensitizers or non-sensitizers.Conclusion The LLNA:BrdU-FCM assay appears to be a relia-ble predictor of skin sensitization protential of chemicals,and it is expected to an alternative method for identifying skin sensitization as a supplementary in safety evaluation of cosmetic ingredient.
10.Isolation,identification,and biological characterization of enterotoxigenic Escherichia coli from a South China tiger
Jing-ru XU ; Zhi-hao ZHU ; Yu-qi LI ; Si-si FAN ; Ya-li KANG ; Yu-bin ZHUO ; Ling-shan HUANG ; Shu-qi QIU ; XUE-YUXI ; Xiao-ping WU ; Yu-ting LIAO ; Wei-ye LIN ; Xiao-ziyi XIAO ; Xue-jin LI ; Teng-teng CHEN ; Xi-pan LIN ; Kai-xiong LIN ; Ke-wei FAN
Chinese Journal of Zoonoses 2025;41(6):567-573
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.

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