1.Differences in deltamethrin resistance and kdr gene mutation in Culex tritaeniorhynchus population in and outside the Yellow Sea wetland
Xiao-er ZHANG ; Zhi-ming WU ; Ye TIAN ; Qian CUI ; Yu-qian JI ; Huan WANG ; Shu-juan YANG ; Yi-chao ZHAO ; Yu WANG ; Hua-yu YIN ; Yu DING ; Guo-jin YAN ; Min-sen ZHAO ; Shou-gang ZHANG ; Bing-dong SONG ; Hong-na CHEN ; Jian GAO ; Wei-fang YANG ; Yu-fu ZHANG ; Hui LIU ; Hong-liang CHU
Acta Parasitologica et Medica Entomologica Sinica 2026;33(2):101-107
Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.
2.An exploratory study on the effect of ultrasonic waves against Aedes albopictus larvae
Shuqing JIN ; Xinyi CAI ; Heyi WEN ; Jian FAN ; Hui CAO ; Tianyu SHA ; Hongxia LIU ; Yuan FANG ; Qiang GAO
Shanghai Journal of Preventive Medicine 2026;38(7):550-555
ObjectiveTo evaluate the larvicidal effect of ultrasonic waves against Aedes albopictus larvae at various exposure parameters (distance and time), and to preliminarily investigate the effects of different containers (water volume and depth) and ultrasonic devices on the larvicidal efficacy, so as to provide experimental evidence for the application of ultrasound-based mosquito control technology. MethodsUnder controlled laboratory conditions, two commercially available ultrasonic devices [40 kHz/300 W and (50±5) kHz/70 W] were used to systematically examine the effects of exposure distance (20, 40, 60, 80, and 100 cm), exposure duration (1, 3, 6, 15 and 60 min), larval instar(Ⅰ‒Ⅱ and Ⅲ‒Ⅳ), and container type on the immediate mortality of Aedes albopictus larvae collected from urban areas of Shanghai. Statistical analysis of the mortality rates of larvae among different experimental groups was performed using the chi-square test. ResultsUltrasonic exposure exerted a detectable larvicidal effect against Aedes albopictus larvae of all instars. For early-instar larvae, exposure time significantly affected mortality at all tested distances (20, 40, 60, 80 and 100 cm), with χ² values ranging from 25.57 to 32.74 ( all P<0.001). No significant distance effect was observed in the first and second instar larvae after short-term exposure (1 and 3 min; P>0.05). However, a distance-dependent effect emerged from 6 min onward (P<0.05). During short-term exposure (1 min and 3 min) at close range (20 cm and 40 cm), the immediate mortality of the third and fourth instar larvae was higher than that of the first and second instar larvae. Conversely, during prolonged exposure (15 min and 60 min), the first and second instar larvae exhibited significantly higher mortality than that of the third and fourth instar larvae. These results indicated that larval mortality was jointly influenced by exposure duration and distance. Preliminary experiments indicated that larvicidal efficacy in shallow water was lower than that in deep water. No significant difference in larvicidal effect was observed between the two ultrasonic devices with different frequencies and power outputs. ConclusionUnder laboratory conditions, ultrasound can effectively kill Aedes albopictus larvae, and the larvicidal effect is jointly influenced by larval instar, exposure distance, and aquatic environment. Compact ultrasonic devices show potential for field application in biological mosquito control.
3.Investigations of tick habitats and potential pathogens carried in urban environments of Jiangsu Province
Zhi-ming WU ; Ye TIAN ; Wei-fang YANG ; Hong-na CHEN ; Jian GAO ; Hui LIU ; Yu-fu ZHANG ; Gan CAO ; Hong-liang CHU
Acta Parasitologica et Medica Entomologica Sinica 2026;33(3):192-197
Objective To investigate the species composition, distribution, density, and pathogen-carrying status of host-seeking ticks in urban environments of Jiangsu Province, and to provide a scientific basis for the prevention and control of tick-borne diseases in urban settings. Methods From April to September 2023, a survey on host-seeking ticks was conducted in three types of habitats (city parks, residential areas, and street greenbelts) across 54 counties (cities, districts) of 13 prefecture-level cities in Jiangsu Province by using the flagging method. RStudio 4.4.3 (Windows version) was employed to perform chi-square test analysis on the species composition of ticks across different months, and Friedman test (for multiple paired samples) was applied to analyze monthly changes in the average tick density index among different habitats. Quantitative real-time PCR was performed to detect pathogens in the captured ticks. Results A total of 863 host-seeking ticks were captured from 54 habitats in 24 counties (cities, districts) of 11 prefecture-level cities (Nanjing, Wuxi, Changzhou, Suzhou, Nantong, Huai'an, Yancheng, Yangzhou, Zhenjiang, Taizhou, and Suqian) in Jiangsu Province, whereas no ticks were captured in Xuzhou and Lianyungang. The collected ticks belonged to three species, with Haemaphysalis longicornis being the dominant species (accounting for 82.62%), followed by Haemaphysalis flava and Hae. phasiana. The average density index of ticks in positive habitats was 3.20 ticks/ (flag·100 m). In terms of tick density among prefecture-level cities, Wuxi had the highest density[13.55 ticks/(flag·100 m)], whereas Nanjing and Taizhou had the lowest[both,0.20 ticks/(flag·100 m)]. With respect to the types of positive habitats,46 positive city parks,7 positive residential areas, and 1 positive street greenbelt were found, with the average tick density index being 3.46, 1.86, and 3.60 ticks/flag · 100 m, respectively. No statistically significant differences were observed in the monthly variations in the average tick density index among different habitats (P>0.05). Pathogen detection showed no Bandavirus dabieense, Rickettsia, or Borrelia burgdorferi in the collected ticks. Conclusions Host-seeking ticks have established populations in urban environments across most prefecture-level cities in Jiangsu Province, with Hae. longicornis identified as the dominant species. City parks serve as the primary breeding habitats for these ticks. Strengthening tick surveillance and control measures in densely populated and frequently visited areas, such as city parks and residential neighborhoods, is crucial for the effective prevention and control of urban tick-borne diseases.
4.Expert consensus on surgical treatment and rehabilitation for competitive sports athletes returning to sports after anterior cruciate ligament injury (version 2025)
Kai HUANG ; Lunhao BAI ; Qing BI ; Hong CHEN ; Jiwu CHEN ; Xuesong DAI ; Wenyong FEI ; Weili FU ; Zhizeng GAO ; Lin GUO ; Yinghui HUA ; Jingmin HUANG ; Suizhu HUANG ; Xuan HUANG ; Jian LI ; Qiang LI ; Shuzhen LI ; Yanlin LI ; Yunxia LI ; Zhong LI ; Ning LIU ; Yuqiang LIU ; Wei LU ; Hongbin LYU ; Haile PAN ; Xiaoyun PAN ; Chao QI ; Weiliang SHEN ; Luning SUN ; Jin TANG ; Zimin WANG ; Bide WANG ; Ru WANG ; Shaobai WANG ; Licheng WEI ; Weidong XU ; Yongsheng XU ; Jizhou YANG ; Liang YANG ; Rui YANG ; Hongbo YOU ; Tengbo YU ; Jiakuo YU ; Bing YUE ; Hua ZHANG ; Hui ZHANG ; Qingsong ZHANG ; Xintao ZHANG ; Jiajun ZHAO ; Lilian ZHAO ; Qichun ZHAO ; Song ZHAO ; Jiapeng ZHENG ; Jiang ZHENG ; Zhi ZHENG ; Jingbin ZHOU ; Jinzhong ZHAO
Chinese Journal of Trauma 2025;41(4):325-338
With the rapid development of competitive sports, the incidence of anterior cruciate ligament (ACL) injury is on the rise. Such injuries may shorten athletes′ career and lead to other long-term adverse consequences. Although athletes generally recover well after ACL reconstruction, many still struggle to return to their pre-injury performance levels. Advances in the understanding of ACL anatomy and injury mechanisms, along with the evolution of surgical techniques and rehabilitation methods, have provided more individualized and tailored options for athletes following ACL injuries. However, there is currently no consensus in China regarding surgical and rehabilitation strategies for competitive athletes aiming to return to sports after ACL injuries. To this end, the Sports Medicine Committee of the Chinese Research Hospital Association and the Editorial Board of the Chinese Journal of Trauma jointly formulated the Expert consensus on surgical treatment and rehabilitation for competitive sports athletes returning to sports after anterior cruciate ligament injury ( version 2025), and presented 14 recommendations covering surgical indications, preoperative rehabilitation, surgical timing, surgical strategies and postoperative rehabilitation strategies, aiming to improve the surgical treatment and rehabilitation system for ACL injuries in competitive athletes and facilitate their return to high-level sports performance after injury.
5.Clinical guideline for vertebral augmentation of acute symptomatic osteoporotic thoracolumbar compression fractures (version 2025)
Bolong ZHENG ; Wei MEI ; Yanzheng GAO ; Liming CHENG ; Jian CHEN ; Qixin CHEN ; Liang CHEN ; Xigao CHENG ; Jian DONG ; Jin FAN ; Shunwu FAN ; Xiangqian FANG ; Zhong FANG ; Shiqing FENG ; Haoyu FENG ; Haishan GUAN ; Yong HAI ; Baorong HE ; Lijun HE ; Yuan HE ; Hua HUI ; Weimin JIANG ; Junjie JIANG ; Dianming JIANG ; Xuewen KANG ; Hua GUO ; Jianjun LI ; Feng LI ; Li LI ; Weishi LI ; Chunde LI ; Qi LIAO ; Baoge LIU ; Xiaoguang LIU ; Xuhua LU ; Shibao LU ; Bin LIN ; Chao MA ; Xuexiao MA ; Renfu QUAN ; Limin RONG ; Honghui SUN ; Tiansheng SUN ; Yueming SONG ; Hongxun SANG ; Jun SHU ; Jiacan SU ; Jiwei TIAN ; Xinwei WANG ; Zhe WANG ; Zheng WANG ; Zhengwei XU ; Huilin YANG ; Jiancheng YANG ; Liang YAN ; Feng YAN ; Guoyong YIN ; Xuesong ZHANG ; Zhongmin ZHANG ; Jie ZHAO ; Yuhong ZENG ; Yue ZHU ; Rongqiang ZHANG
Chinese Journal of Trauma 2025;41(9):805-818
Acute symptomatic osteoporotic thoracolumbar compression fracture (ASOTLF) can lead to chronic low back pain, kyphosis deformity, pulmonary dysfunction, loss of mobility, and even life-threatening complications. Vertebral augmentation is currently the mainstream treatment method for this condition. In 2019, the Editorial Board of Chinese Journal of Trauma and the Spinal Trauma Group of Orthopedic Surgeons Branch of Chinese Medical Doctor Association collaboratively led the development of Clinical guideline for vertebral augmentation for acute symptomatic osteoporotic thoracolumbar compression fractures. Six years later, with advances in clinical diagnosis and treatment techniques as well as accumulating evidence in related fields, the 2019 guideline requires updating. To this end, the Spinal Trauma Group of Orthopedic Surgeons Branch of Chinese Medical Doctor Association, the Spinal Health Professional Committee of China Human Health Science and Technology Promotion Association, and the Minimally Invasive Orthopedics Professional Committee of Shaanxi Medical Doctor Association have organized experts in the field to develop the Clinical guideline for vertebral augmentation of acute symptomatic osteoporotic thoracolumbar compression fractures ( version 2025) , based on the latest evidence-based medical researches. This guideline incorporates 3 recommendations retained from the 2019 version with updated strength of evidence, along with 12 new recommendations. It provides recommendations from six aspects of diagnosis, pain management, treatment option selection, prevention of postoperative complications, anti-osteoporosis therapy, and postoperative rehabilitation, aiming to provide a reference for standard treatment of vertebral augmentation for ASOTLF in hospitals at all levels.
6.Non-coding RNAs in alcohol-associated liver disease
Ge ZENG ; Hui GAO ; Yanchao JIANG ; Nazmul HUDA ; Themis THOUDAM ; Zhihong YANG ; Jing MA ; Jian SUN ; Suthat LIANGPUNSAKUL
Liver Research 2025;9(2):81-93
Non-coding RNAs(ncRNAs),encompassing microRNAs(miRNAs),long non-coding RNAs(lncRNAs),and circular RNAs(circRNAs),have emerged as critical regulators of gene expression and cellular function.In alcohol-associated liver disease(ALD),chronic alcohol consumption disrupts the expression and function of ncRNAs in the liver and circulation,contributing to the disease's pathogenesis and progression.Dysregulated ncRNAs influence key pathways involved in hepatocyte injury,lipid metabolism,inflam-mation,and hepatic stellate cell(HSC)activation,thereby exacerbating steatosis,inflammation,and fibrosis.Furthermore,extracellular vesicles play a pivotal role in mediating ncRNA-driven intercellular communication,amplifying liver damage and fibrosis.This review provides a comprehensive overview of the multifaceted roles of ncRNAs in ALD,with a focus on their mechanistic contributions to disease development and progression.Additionally,we discuss the potential of ncRNAs as diagnostic biomarkers and therapeutic targets,emphasizing their translational relevance in addressing the burden of ALD.
7.The role of SIRT7 in regulating epithelial-mesenchymal transition(EMT)to promote glioma cell proliferation and migration
Jiang-Ting WANG ; Kai SUN ; Mou GAO ; Gang CHENG ; Wen-Ying LYU ; Chun-Hui ZHOU ; Lei LIANG ; Jian-Ning ZHANG
Medical Journal of Chinese People's Liberation Army 2025;50(1):57-68
Objective To investigate the expression of the histone deacetylase SIRT7 in glioma cells and its impact on epithelial-mesenchymal transformation(EMT),as well as its effects on proliferative,migratory and invasive capabilities of glioma cells.Methods Bioinformatics analysis was conducted on data from glioma patients in the Cancer Genome Atlas(TCGA)and the Chinese glioma Genome Atlas(CGGA)databases to explore the expression of SIRT7 gene in gliomas and its correlation with tumor grading,molecular characteristics and patient clinical prognosis.Glioma cells were randomly divided into control,SIRT7 knockdown,SIRT7 overexpression,drug treatment(10 μmol/L hydrochlorothiazide)and drug(10 μmol/L hydrochlorothiazide)+SIRT7 overexpression groups.The CCK-8 assay,cell scratch assay and Transwell assay were used to observe the effects of upregulating and downregulating SIRT7 expression on glioma cell proliferation,migration and invasion.RT-qPCR and Western blotting were employed to detect the effects of SIRT7 on the expression of neural cadherin(N-cadherin),Vimentin,E-cadherin,transforming growth factor-β(TGF-β),Ki-67,and Smad3 protein in glioma cells.Nude mouse tumor-bearing experiments were conducted to observe the effect of SIRT7 knockdown on glioma growth.Results Higher expression levels of SIRT7 gene were associated with poorer clinical prognosis(P<0.0001).SIRT7 expression levels were significantly correlated with tumor grading and 1p19q coding status(P<0.01).Compared with normal HA cells,glioma cells showed significantly increased SIRT7 expression levels(P<0.01).CCK-8 assay results indicated that,compared with control group,the proliferation activity of glioma cells in SIRT7 knockout group was significantly decreased(P<0.01),while SIRT7 overexpression group showed significantly increased proliferation activity(P<0.01).EdU assay results showed that,compared with control group,the proportion of glioma cells in the proliferative stage was significantly decreased in SIRT7 knockdown group(P<0.01),and significantly increased in SIRT7 overexpression group(P<0.01).Western blotting results revealed that,compared with control group,the protein expression levels of TGF-β,Smad3,N-cadherin and Vimentin were significantly decreased in SIRT7 knockdown group(P<0.01),while the expression level of E-cadherin protein was significantly increased(P<0.05).SIRT7 overexpression group showed significantly increased protein expression levels of TGF-β,Smad3,N-cadherin and Vimentin(P<0.05),and a significantly decrease in E-cadherin protein expression level(P<0.05).Scratch assay results indicated that,compared with control group,the migration ability of cells in SIRT7 knockdown group and drug group was significantly decreased(P<0.01),and SIRT7 overexpression group showed significantly increased cell migration ability(P<0.05).Compared with drug group,drug+SIRT7 overexpression group exhibited significantly increased cell migration ability(P<0.01).Transwell assay results showed that,compared with control group,the migration and invasion abilities of cells in SIRT7 knockdown group and drug group were significantly decreased(P<0.01),and SIRT7 overexpression group exhibited significantly increased migration and invasion abilities(P<0.01).Compared with drug group,drug+SIRT7 overexpression group showed significantly increased migration and invasion abilities(P<0.01).Nude mouse tumor-bearing assay results indicated that the volume and weight of glioma in SIRT7 knockdown group were significantly reduced compared with control group(P<0.01).Conclusions Glioma patients with high SIRT7 expression have poorer clinical prognosis.SIRT7 can regulate the TGF-β/Smad3 pathway to mediate EMT,promoting the proliferation and migration of glioma cells.SIRT7 knockdown can inhibit the growth of transplanted gliomas in nude mice.
8.Correlation between dynamic contrast-enhanced MRI imaging and clinical pathological features of invasive breast cancer and lymphovascular invasion
Shi-Qi GUO ; Yu-Jiao XIE ; Qing-Yang LI ; Si-Yi CHEN ; Jia-Hong SUN ; Zhao-Feng GAO ; Jun-Qing LIANG ; Yu-Hui CHEN ; Bao-Shi BAO ; Li ZHU ; Jian-Dong WANG
Medical Journal of Chinese People's Liberation Army 2025;50(7):847-854
Objective To explore the relationship between dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)and clinical pathological features of invasive breast cancer and lymphovascular invasion(LVI).Methods Imaging and clinical pathological data were retrospectively collected from 508 patients with invasive breast cancer who underwent breast DCE-MRI at the First Medical Center of Chinese PLA General Hospital from January 2019 to August 2021.Patients were divided into the LVI-positive(LVI+)group(n=79)and LVI-negative(LVI-)group(n=429)based on postoperative pathological results.Univariate and multivariate logistic regression analyses were used to identify risk factors for LVI.Results Compared with LVI-group,LVI+group had a higher proportion of patients aged<45 years(44.3%vs.27.0%,P=0.002),non-mass-like enhancement(NME)(31.7%vs.17.7%,P=0.004),Ki-67 expression rate(40.0%vs.30.0%,P<0.001),high Ki-67 expression(94.9%vs.78.1%,P=0.001),Luminal B subtype(76.0%vs.60.1%,P=0.008),and positive axillary lymph nodes rate(72.2%vs.31.5%,P<0.001),while the proportion of Luminal A subtype was lower(2.5%vs.21.5%,P<0.001).Univariate and multivariate logistic regression analyses showed that age≥45 years(OR=0.468,95%CI 0.280-0.783,P=0.004)was an independent protective factor for LVI,while NME(OR=1.987,95%CI 1.126-3.444,P=0.016)was an independent risk factor.Compared with Luminal A subtype,patients with Luminal B subtype(OR=10.482,95%CI 3.164-64.923,P=0.001),HER-2 overexpression subtype(OR=11.571,95%CI 2.755-79.341,P=0.003)and triple-negative subtypes(OR=8.433,95%CI 1.985-57.908,P=0.009)had a higher risk of LVI.Conclusions Age≥45 years is an independent protective factor for LVI,while NME is an independent risk factor.Among molecular subtypes,patients with Luminal B,HER-2 overexpression and triple-negative subtypes have a higher risk of LVI compared with the Luminal A subtype.
9.Optimization Study of Rat Models for Sequelae of Pelvic Inflammatory Disease
Zhen LIU ; Wei-ling WANG ; Yun-cheng MA ; Yu-xi WANG ; Yuan TIAN ; Qian LI ; Xiao-zhu WANG ; Xiao-yao LIU ; Mei JIANG ; Wen-hui XU ; Jian GAO ; Ting WANG
Progress in Modern Biomedicine 2025;25(12):1921-1930
Objective:To establish a stable rat model of sequelae of pelvic inflammatory disease(SPID)with clinical characteristics,and to provide a reliable experimental model for the study of the pharmcological effect and mechanism of SPID.Methods:Twenty-four 7-week-old SD rats were divided into sham operation group,model-A(108 cfu/mL mixed bacterial solution,0.2 mL),model-B(109 cfu/mL mixed bacterial solution 0.2 mL),and model-C(108 cfu/mL E.coli 0.2 mL).The weight of the rat's uterine was weighed and the uterine index was calculated.The automatic hematology analyzer was used to detect the blood routine;hematoxylin-eosin staining(HE)and masson staining were used to detect uterine pathlogical changes in rats.Enzyme-linked immunosorbent assay(ELISA)was used to detect interleukin-1β(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in rat uterine tissue homogenates.Western blot was used to detect the expression of proteins related to NF-κB signaling pathway.Results:Compared with the sham operation group,the uterine index of model-A,model-B,and model-C were significantly increased(P<0.05,P<0.01).The levels of WBC and NE in the model-A increased significantly(P<0.01).The level of LY in model-B decreased significantly(P<0.01).The levels of IL-1β,TNF-α in model-A,model-B,and model-C were significantly increased(P<0.01).The levels of IL-6 in model-A and model-B were significantly increased(P<0.05,P<0.01).The collagen volume fraction of model-A and model-B were significantly increased(P<0.01).Mechanism study indicates that the expression levels of p-IKKβ/IKKβ,p-IκBα/IκBα and p-p65/p65 in model-A were significantly increased(P<0.01),and the expression levels of IκBα/β-actin were significantly decreased(P<0.01).The expression level of p-IKKβ/IKKβ in model-B was significantly increased(P<0.01).Conclusions:A stable rat model of SPID that conforms to clinical characteristics can be successfully constructed by combining 0.2 mL of mixed bacterial solution with a concentration of 108 cfu/mL and mechanical injury.This modeling method intervened in the expression of the NF-κB inflammatory signaling pathway.
10.Epidemiological distribution characteristics and transmission patterns of Campylobacter in a Shandong broiler slaughterhouse
Shuai MIAO ; Xiu-mei HUANG ; Lin WANG ; Jun-hui LIU ; Jian-mei ZHAO ; Yu-bin GAO ; Shi-ping SONG ; Si-yu ZHANG ; Na LIU ; Ge ZHAO ; Xi-yue ZHANG ; Jun-wei WANG ; Juan WANG ; Zhi-na QU
Chinese Journal of Zoonoses 2025;41(6):583-591
This research investigated the contamination level,distribution of drug-resistant strains,and molecular epidemiologi-cal characteristics of Campylobacter,and further explored transmission pathways and prevention strategies.Cecum,chicken carcass,chicken product,and environmental samples,as well as swabs from workers'hands,were collected from a slaughterhouse in a large broiler group in the Jiaodong area between August 2023 and July 2024.Quantitative contamination assessment of Campylobacter in chicken carcasses and chicken products was performed.After microbial mass spectrometry identification,the representative strains of different links were selected for drug resistance testing and whole genome sequencing(WGS).On the basis of the sequencing results,the resistance genes,virulence genes,multilocus sequence typing(MLST),and phylogenetic characteristics of representative strains were analyzed.Homology comparisons were performed between isolates and strains from patients with diarrhea in the NCBI database.A total of 297 Campylobacter strains were isolated from 806 samples,and the overall detection rate was 36.85%.The detection rate of Campylobacter was highest in the evisceration process(47.33%),followed by the cutting process(35.64%).Overall,the Campylo-bacter detection rate first increased,then decreased,and subsequently increased.Drug sensitivity testing revealed that 90 isolates were resistant to nalidixic acid and ciprofloxacin,and 94.97%of isolates were resistant to tetracycline.WGS showed that both Campylo-bacter jejuni(C.jejuni)and Campylobacter coli(C.coli)carried many drug resistance and virulence genes.ST-14176 of C.jejuni was isolated for the first time herein.The predominant ST-8261 strain of C.jejuni and ST-860,ST-829,and ST-1586 strains of C.coli are known to cause human diarrhea.LOS expression genes associated with Guillain-Barré syndrome(GBS)were detected in both C.jejuni isolates from the slaughter chain and patients with GBS.Some strains exhibited close genetic relatedness to human-derived Campylo-bacter strains from the NCBI database.The detection rate of Campylobacter in the slaughterhouse first increased,then decreased,and subsequently increased,and the quantitative contamination level of each link was similar to the detection rate.Quantitative analysis of chicken carcasses/products revealed that the average bacterial load was highest in eviscerated carcasses(102.80 cfu/g),and the high-est amount of Campylobacter in chicken products reached 451.80 cfu/g.Abundant drug resistance genes and virulence genes were iden-tified,and the drug resistance genes were highly correlated with the drug resistance rate.Therefore,surveillance intensity and control measures for Campylobacter in slaughter processes should be strengthened.


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