1.Advancements in Gas-releasing Micro/Nanoplatforms for Overcoming MDR Bacterial Infections in Diabetic Wounds
Ruo-Can LIU ; Yu-Qian WANG ; Shuai ZHANG ; Shao-Zhi ZUO ; Yun-Di WU ; Xi-Long WU
Progress in Biochemistry and Biophysics 2026;53(5):1356-1375
Chronic diabetic wounds, severely complicated by multidrug-resistant (MDR) bacterial infections, represent a profound and escalating global health crisis. The intrinsically hostile microenvironment of diabetic wounds, characterized by localized hypoxia, persistent oxidative stress, and poor vascularization, creates an ideal niche for opportunistic pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa. These bacteria readily construct dense extracellular polymeric substance (EPS) biofilms, which not only physically shield the microbes from host immune responses but also actively trap the wound in a state of chronic, unresolved inflammation. Consequently, conventional systemic and topical antibiotic therapies are becoming increasingly futile, as poor perfusion at the wound site restricts drug bioavailability, while the rapid genetic evolution of bacteria and the impenetrable nature of biofilms lead to catastrophic treatment failures, often culminating in severe tissue necrosis and lower-extremity amputations. To circumvent the limitations of traditional antimicrobials, therapeutic gas delivery has emerged as a highly promising, paradigm-shifting strategy. Gaseous signaling molecules, particularly nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S), and hydrogen (H2), possess unique physicochemical properties that allow them to seamlessly penetrate dense biofilm matrices and cellular membranes. Once inside, these gases operate via multi-targeted mechanisms that are incredibly difficult for bacteria to develop resistance against; for instance, NO induces severe lipid peroxidation and DNA cleavage in bacteria, CO downregulates pro-inflammatory cytokines, H2S significantly accelerates endothelial cell migration for neovascularization, and H2 acts as a powerful selective antioxidant to neutralize tissue-damaging reactive oxygen species (ROS). Together, these therapeutic gases not only exert broad-spectrum bactericidal effects but also actively reprogram the wound bed by promoting the critical M1-to-M2 macrophage polarization and stimulating angiogenesis. Despite their immense biological potential, the direct clinical translation of gas therapies is severely hindered by inherent physicochemical drawbacks, including extreme volatility, short physiological half-lives, poor aqueous solubility, and the high risk of off-target systemic toxicity, if applied indiscriminately. To conquer these immense pharmacokinetic barriers, cutting-edge advancements in materials science have driven the development of gas-releasing micro- and nanoplatforms. Utilizing sophisticated carriers such as metal-organic frameworks (MOFs), mesoporous silica, polymeric nanoparticles, liposomes, and injectable hydrogels, researchers can now encapsulate gas-donor molecules to achieve sustained, localized delivery. More importantly, these advanced nanoplatforms are ingeniously engineered to be stimuli-responsive. By exploiting the pathological hallmarks of the diabetic wound environment, such as elevated glucose concentrations, acidic pH, and overexpressed ROS, or by utilizing external triggers like near-infrared (NIR) light irradiation and ultrasound, these intelligent platforms ensure on-demand, precise spatio-temporal gas release. This often allows for powerful synergistic combinations, such as photothermal or photodynamic therapy coupled with gas release, thereby obliterating biofilms while sparing healthy tissue. While the therapeutic outcomes of these smart delivery systems in eradicating MDR infections and accelerating tissue repair are unprecedented, several critical challenges remain before widespread clinical adoption, as long-term biosafety profiles of the carrier nanomaterials, complexities in large-scale good manufacturing practice (GMP) production, and stringent regulatory hurdles must be rigorously addressed. Looking forward, the next frontier lies in the realm of precision medicine and theranostics, where future research must focus on the seamless integration of these gas-releasing platforms with flexible, wearable biosensors capable of continuously monitoring wound biomarkers (e.g., pH, temperature, uric acid) in real-time. Coupled with artificial intelligence algorithms to govern automated, closed-loop adaptive dosing, these next-generation smart dressings hold the ultimate potential to comprehensively transform the clinical management of complex, infected diabetic wounds.
2.Advancements in Gas-releasing Micro/Nanoplatforms for Overcoming MDR Bacterial Infections in Diabetic Wounds
Ruo-Can LIU ; Yu-Qian WANG ; Shuai ZHANG ; Shao-Zhi ZUO ; Yun-Di WU ; Xi-Long WU
Progress in Biochemistry and Biophysics 2026;53(5):1356-1375
Chronic diabetic wounds, severely complicated by multidrug-resistant (MDR) bacterial infections, represent a profound and escalating global health crisis. The intrinsically hostile microenvironment of diabetic wounds, characterized by localized hypoxia, persistent oxidative stress, and poor vascularization, creates an ideal niche for opportunistic pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa. These bacteria readily construct dense extracellular polymeric substance (EPS) biofilms, which not only physically shield the microbes from host immune responses but also actively trap the wound in a state of chronic, unresolved inflammation. Consequently, conventional systemic and topical antibiotic therapies are becoming increasingly futile, as poor perfusion at the wound site restricts drug bioavailability, while the rapid genetic evolution of bacteria and the impenetrable nature of biofilms lead to catastrophic treatment failures, often culminating in severe tissue necrosis and lower-extremity amputations. To circumvent the limitations of traditional antimicrobials, therapeutic gas delivery has emerged as a highly promising, paradigm-shifting strategy. Gaseous signaling molecules, particularly nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S), and hydrogen (H2), possess unique physicochemical properties that allow them to seamlessly penetrate dense biofilm matrices and cellular membranes. Once inside, these gases operate via multi-targeted mechanisms that are incredibly difficult for bacteria to develop resistance against; for instance, NO induces severe lipid peroxidation and DNA cleavage in bacteria, CO downregulates pro-inflammatory cytokines, H2S significantly accelerates endothelial cell migration for neovascularization, and H2 acts as a powerful selective antioxidant to neutralize tissue-damaging reactive oxygen species (ROS). Together, these therapeutic gases not only exert broad-spectrum bactericidal effects but also actively reprogram the wound bed by promoting the critical M1-to-M2 macrophage polarization and stimulating angiogenesis. Despite their immense biological potential, the direct clinical translation of gas therapies is severely hindered by inherent physicochemical drawbacks, including extreme volatility, short physiological half-lives, poor aqueous solubility, and the high risk of off-target systemic toxicity, if applied indiscriminately. To conquer these immense pharmacokinetic barriers, cutting-edge advancements in materials science have driven the development of gas-releasing micro- and nanoplatforms. Utilizing sophisticated carriers such as metal-organic frameworks (MOFs), mesoporous silica, polymeric nanoparticles, liposomes, and injectable hydrogels, researchers can now encapsulate gas-donor molecules to achieve sustained, localized delivery. More importantly, these advanced nanoplatforms are ingeniously engineered to be stimuli-responsive. By exploiting the pathological hallmarks of the diabetic wound environment, such as elevated glucose concentrations, acidic pH, and overexpressed ROS, or by utilizing external triggers like near-infrared (NIR) light irradiation and ultrasound, these intelligent platforms ensure on-demand, precise spatio-temporal gas release. This often allows for powerful synergistic combinations, such as photothermal or photodynamic therapy coupled with gas release, thereby obliterating biofilms while sparing healthy tissue. While the therapeutic outcomes of these smart delivery systems in eradicating MDR infections and accelerating tissue repair are unprecedented, several critical challenges remain before widespread clinical adoption, as long-term biosafety profiles of the carrier nanomaterials, complexities in large-scale good manufacturing practice (GMP) production, and stringent regulatory hurdles must be rigorously addressed. Looking forward, the next frontier lies in the realm of precision medicine and theranostics, where future research must focus on the seamless integration of these gas-releasing platforms with flexible, wearable biosensors capable of continuously monitoring wound biomarkers (e.g., pH, temperature, uric acid) in real-time. Coupled with artificial intelligence algorithms to govern automated, closed-loop adaptive dosing, these next-generation smart dressings hold the ultimate potential to comprehensively transform the clinical management of complex, infected diabetic wounds.
3.The Dual Roles of ERK Signaling in Parkinson’s Disease: From Neurotoxicity to Neuroprotection
Chang-Zhi YANG ; Hui WANG ; Min YAN ; Shuai WEI ; Xue-Wen TIAN
Progress in Biochemistry and Biophysics 2026;53(9):2316-2333
Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta and abnormal accumulation of α‑synuclein. Its pathogenesis involves multiple interconnected processes, including oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress, neuroinflammation, and impaired protein homeostasis. Extracellular signal-regulated kinase 1/2 (ERK1/2), a major component of the mitogen-activated protein kinase signaling network, plays an important role in neuronal survival, synaptic plasticity, stress responses, and cell death. However, accumulating evidence indicates that ERK signaling in PD is not unidirectional, as both insufficient activity and sustained overactivation have been associated with neuronal dysfunction and disease progression. In this review, we systematically summarize the evidence for the pathological and protective roles of ERK signaling in PD. Insufficient ERK activity may impair neurotrophic support, synaptic plasticity, mitochondrial homeostasis, and neuronal adaptation to stress, thereby increasing the vulnerability of dopaminergic neurons. In contrast, persistent and excessive ERK activation may promote neuroinflammation, oxidative stress, mitochondrial dysfunction, apoptosis, autophagy-lysosomal impairment, and abnormal α-synuclein accumulation. Conversely, moderate and transient ERK activation induced by neurotrophic factors, bioactive compounds, or exercise may enhance neuronal survival, antioxidant defense, synaptic plasticity, and functional recovery. These apparently contradictory findings suggest that ERK activation itself cannot be simply classified as either neuroprotective or neurotoxic. Based on the available evidence, we propose the concept of an “ERK activity window” to explain the context-dependent effects of ERK signaling in PD. This hypothesis suggests that ERK activity needs to remain within an appropriate dynamic range to maintain neuronal homeostasis and adaptive responses. ERK activity below this range may weaken neurotrophic support and stress resistance, whereas prolonged and high-intensity activation may exceed the adaptive capacity of neurons and glial cells, thereby promoting inflammatory and degenerative processes. Importantly, this functional window should not be regarded as a fixed threshold. Its biological effects are likely determined by the intensity and duration of activation, cell type, subcellular localization, upstream stimuli, interaction with other signaling pathways, and disease stage. This framework may therefore help reconcile the apparently inconsistent findings among different PD models and experimental conditions. From a therapeutic perspective, these findings indicate that ERK should not necessarily be considered a target for simple activation or inhibition. Instead, restoring ERK signaling toward an appropriate functional state may represent a more rational strategy. Exercise is of particular interest because it can simultaneously influence neurotrophic signaling, oxidative stress, inflammation, synaptic plasticity, and ERK activity, potentially promoting adaptive remodeling of ERK signaling according to pathological conditions. Nevertheless, current evidence is predominantly derived from cellular and animal studies, and the dynamic, cell-specific, and spatial characteristics of ERK signaling remain insufficiently defined. Blood-brain barrier penetration, long-term safety, preservation of physiological ERK functions, and the lack of reliable biomarkers for monitoring brain ERK activity also limit clinical translation. Importantly, the “ERK activity window” remains a theoretical framework, and direct clinical evidence that ERK modulation can alter the progression of human PD is currently lacking. Future studies should therefore integrate longitudinal analysis, cell-specific and spatial approaches, and clinical biomarker validation to determine whether precise regulation of ERK signaling can provide a viable strategy for disease-modifying intervention in PD.
4.A multicenter clinical study on intramedullary vancomycin injection for preventing periprosthetic joint infection in total knee arthroplasty
Te LIU ; Jun FU ; Shiguang LAI ; Zhuo ZHANG ; Chi XU ; Lei GENG ; Yang LUO ; Peng REN ; Xin ZHI ; Quanbo JI ; Heng ZHANG ; Runkai ZHAO ; Haichao REN ; Ye TAO ; Qingyuan ZHENG ; Zeyu FENG ; Jianfeng YANG ; Yiming WANG ; Pengcheng LI ; Shuai LIU ; Wei CHAI ; Xiang LI ; Huiwu LI ; Xiaogang ZHANG ; Baochao JI ; Xianzhe LIU ; Xinzhan MAO ; Jianbing MA ; Xiangxiang SUN ; Jiying CHEN ; Yonggang ZHOU ; Jinliang WANG ; Weijun WANG ; Guoqiang ZHANG ; Ming NI
Chinese Journal of Orthopaedics 2025;45(12):803-811
Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.
5.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.
6.Research on Doxorubicin-Induced Cardiotoxicity Mechanism and Its Forensic Ap-plication
Shuai ZHANG ; Hong-Fei XU ; Zhi-Xiang ZHANG ; Ying WANG ; Shao-Hua ZHU
Journal of Forensic Medicine 2025;41(2):120-126
Doxorubicin is a commonly used antitumor drug for the treatment of various cancers.How-ever,its clinical application is greatly restricted by its severe cardiotoxicity.At present,doxorubicin-induced cardiotoxicity is categorized into acute and chronic forms,depending on the dosage and dura-tion of exposure,which may eventually lead to the occurrence of heart failure.The pathogenesis of doxorubicin cardiotoxicity is associated with oxidative stress,mitochondrial damage,calcium overload,dysregulation of autophagy,and apoptosis.In forensic medical practice,cases of poisoning or even car-diac death caused by doxorubicin showed no obvious changes in cardiac morphology through routine forensic pathological examinations.The paper aims to summarize the research on the mechanisms of action of doxorubicin-induced cardiotoxicity in recent years,analyze and discuss the possible pathways of cardiomyocyte injury caused by doxorubicin,and provide references for research on the mechanisms of doxorubicin-induced cardiotoxicity and forensic application.
7.A small-molecule anti-cancer drug for long-acting lysosomal damage.
Shulin ZHAO ; Qingjie BAI ; Guimin XUE ; Juan WANG ; Luyao HU ; Xueqian WANG ; Yan LI ; Shuai LU ; Yangang SUN ; Zhiqiang ZHANG ; Yanling MU ; Yanle ZHI ; Qixin CHEN
Acta Pharmaceutica Sinica B 2025;15(11):5867-5879
Lysosomes represent a promising target for cancer therapy and reducing drug resistance. However, the short treatment time and low efficiency of lysosomal targeting have limited the application in lysosome-targeting anticancer drugs. In this study, we proposed an adhesive-bandage approach and synthesized a new lysosomal targeting drug, namely long-term lysosome-targeting anticancer drug (LLAD). It contains a SLC38A9-targeting covalently bound moiety and an alkaline component both to prolong the inhibition of SLC38A9 in lysosomes and alkalinize lysosomes. Upon short term and low-dose treatment of HeLa cells, at passage 0, with LLAD, it rapidly alkalinized lysosomes and also can be detected in lysosomes even at passage 15. LLAD induced apoptosis in HeLa cells through long-term lysosomal damage, and showed better long-term anticancer effect than cisplatin in vivo. Overall, our study paves the way for developing long-term lysosomal targeting drugs to treat cancer and overcome the drug resistance of cancer cells, and also provides a candidate drug, LLAD, for treating cancer.
8.A novel loop-structure-based bispecific CAR that targets CD19 and CD22 with enhanced therapeutic efficacy against B-cell malignancies.
Lijun ZHAO ; Shuhong LI ; Xiaoyi WEI ; Xuexiu QI ; Qiaoru GUO ; Licai SHI ; Ji-Shuai ZHANG ; Jun LI ; Ze-Lin LIU ; Zhi GUO ; Hongyu ZHANG ; Jia FENG ; Yuanyuan SHI ; Suping ZHANG ; Yu J CAO
Protein & Cell 2025;16(3):227-231
9.Exploring the Efficacy of BMSC Transplantation via Various Pathways for Treating Cholestatic Liver Fibrosis in Mice.
Jun Jie REN ; Zi Xu LI ; Xin Rui SHI ; Ting Ting LYU ; Xiao Nan LI ; Min GE ; Qi Zhi SHUAI ; Ting Juan HUANG
Biomedical and Environmental Sciences 2025;38(4):447-458
OBJECTIVE:
To compare the therapeutic efficacy of portal and tail vein transplantation of bone marrow-derived mesenchymal stem cells (BMSCs) against cholestatic liver fibrosis in mice.
METHODS:
BMSCs were isolated and co-cultured with starvation-activated hepatic stellate cells (HSCs). HSC activation markers were identified using immunofluorescence and qRT-PCR. BMSCs were injected into the liver tissues of bile duct ligation (BDL) mice via the tail and portal veins. Histomorphology, liver function, inflammatory cytokines, and the expression of key proteins were all determined in the liver tissues.
RESULTS:
BMSCs inhibited HSC activation by reducing α-SMA and collagen I expression. Compared to tail vein injection, DIL-labeled BMSCs injected through the portal vein maintained a high homing rate in the liver. Moreover, BMSCs transplanted through the portal vein resulted in greater improvement in liver color, hardness, and gallbladder size than did those transplanted through the tail vein. Furthermore, BMSCs injected by portal vein, but not tail vein, markedly ameliorated liver function, reduced the secretion of inflammatory cytokines, including TNF-α, IL-6, and IL-1β, and decreased α-SMA + hepatic stellate cell (HSC) activation and collagen fiber formation.
CONCLUSION
The therapeutic effect of BMSCs on cholestatic liver fibrosis in mice via portal vein transplantation was superior to that of tail vein transplantation. This comparative study provides reference information for further BMSC studies focused on clinical cholestatic liver diseases.
Animals
;
Mice
;
Mesenchymal Stem Cell Transplantation
;
Liver Cirrhosis/etiology*
;
Male
;
Cholestasis/therapy*
;
Mice, Inbred C57BL
;
Hepatic Stellate Cells
;
Mesenchymal Stem Cells
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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