1.Nanopackaged Astaxanthin Improves Demyelination in Multiple Sclerosis Model Mice by Scavenging Excessive Endogenous Formaldehyde
Wan-Jia LÜ ; Xin ZENG ; Zhi-Qian TONG ; Yang XING ; Xu YANG ; Mei-Na WU ; Ping MA
Progress in Biochemistry and Biophysics 2026;53(2):442-457
ObjectiveMultiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS); however, its underlying neurological pathogenic mechanisms remain incompletely understood. Endogenous formaldehyde (FA), a metabolic byproduct of methylation-demethylation cycles, has recently been implicated in neurotoxicity, oxidative damage, and cognitive impairment. This study aimed to investigate whether excessive FA contributes to myelin sheath demyelination in mice and to evaluate the protective effects and mechanisms of two FA-elimination strategies: sodium bisulfite (NaHSO3), a classical FA scavenger, and polyethylene glycol-modified astaxanthin nanoparticles (PEG-ATX@NPs), a brain-targeted nano-antioxidant formulation. MethodsA chronic demyelination model was established by feeding female C57BL/6J mice a diet containing 0.2% cuprizone (CPZ) for four weeks, followed by a two-week intervention period. Eighty mice were randomly assigned to four groups: NS (normal saline), CPZ+NS, CPZ+NaHSO3, and CPZ+PEG-ATX@NPs. Behavioral tests, including open-field, Y-maze, and pole-climbing assays, were conducted to assess locomotor activity, motor coordination, and working memory. FA levels in serum, corpus callosum, and spinal cord were measured using an Na-FA fluorescent probe and quantified via in vivo and ex vivo fluorescence imaging. Neuroinflammatory responses were evaluated by measuring TNF-α, IL-1β, and IL-6 levels using ELISA, while oxidative stress was assessed by reactive oxygen species (ROS) fluorescence intensity. Demyelination was examined via Luxol fast blue staining, and microglial activation was analyzed by Iba1 immunofluorescence. Correlation analyses were performed to explore relationships among FA levels, inflammatory cytokines, ROS intensity, and behavioral parameters. ResultsCompared with the NS group, mice in the CPZ+NS group exhibited significant weight loss, impaired motor coordination and memory, and markedly reduced myelin regeneration (P<0.05). FA levels and pro-inflammatory cytokines were significantly elevated in serum, corpus callosum, and spinal cord (P<0.05). FA-associated fluorescence in brain and spinal tissues, as well as ROS intensity across all tissues examined, also increased substantially (P<0.05). CPZ treatment induced pronounced microglial activation and severe demyelination in the corpus callosum (P<0.01). Both NaHSO3 and PEG-ATX@NPs effectively reduced FA accumulation in the brain and spinal cord, attenuated demyelination, suppressed microglial activation, decreased inflammatory cytokine levels, and improved motor and cognitive performance. These results confirm that CPZ induced severe demyelination accompanied by oxidative stress, neuroinflammation, and abnormal FA accumulation. Following intervention with either NaHSO3 or PEG-ATX@NPs, endogenous FA levels in the CNS were substantially reduced. Both treatments alleviated demyelination and significantly decreased the number of activated microglia. Levels of TNF-α, IL-1β, and IL-6 in serum, corpus callosum, and spinal cord were downregulated. Behavioral performance improved significantly, as evidenced by enhanced locomotor activity, better coordination, and improved memory function. These findings indicate that both FA-scavenging agents mitigate CPZ-induced biochemical and behavioral abnormalities. ConclusionThis study demonstrates that excessive endogenous FA is closely associated with cognitive impairment, inflammatory dysregulation, and demyelination in a CPZ-induced chronic demyelination mouse model. Clearing abnormally elevated FA effectively reduces neuroinflammation, suppresses microglial overactivation, decreases oxidative stress, and alleviates demyelination, ultimately improving motor and cognitive outcomes in mice. These results suggest that targeting endogenous FA represents a promising therapeutic strategy for MS and other demyelinating disorders. Further investigations are warranted to explore the long-term safety, dosage optimization, and molecular pathways involved in FA-mediated neurotoxicity.
2.Nanopackaged Astaxanthin Improves Demyelination in Multiple Sclerosis Model Mice by Scavenging Excessive Endogenous Formaldehyde
Wan-Jia LÜ ; Xin ZENG ; Zhi-Qian TONG ; Yang XING ; Xu YANG ; Mei-Na WU ; Ping MA
Progress in Biochemistry and Biophysics 2026;53(2):442-457
ObjectiveMultiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS); however, its underlying neurological pathogenic mechanisms remain incompletely understood. Endogenous formaldehyde (FA), a metabolic byproduct of methylation-demethylation cycles, has recently been implicated in neurotoxicity, oxidative damage, and cognitive impairment. This study aimed to investigate whether excessive FA contributes to myelin sheath demyelination in mice and to evaluate the protective effects and mechanisms of two FA-elimination strategies: sodium bisulfite (NaHSO3), a classical FA scavenger, and polyethylene glycol-modified astaxanthin nanoparticles (PEG-ATX@NPs), a brain-targeted nano-antioxidant formulation. MethodsA chronic demyelination model was established by feeding female C57BL/6J mice a diet containing 0.2% cuprizone (CPZ) for four weeks, followed by a two-week intervention period. Eighty mice were randomly assigned to four groups: NS (normal saline), CPZ+NS, CPZ+NaHSO3, and CPZ+PEG-ATX@NPs. Behavioral tests, including open-field, Y-maze, and pole-climbing assays, were conducted to assess locomotor activity, motor coordination, and working memory. FA levels in serum, corpus callosum, and spinal cord were measured using an Na-FA fluorescent probe and quantified via in vivo and ex vivo fluorescence imaging. Neuroinflammatory responses were evaluated by measuring TNF-α, IL-1β, and IL-6 levels using ELISA, while oxidative stress was assessed by reactive oxygen species (ROS) fluorescence intensity. Demyelination was examined via Luxol fast blue staining, and microglial activation was analyzed by Iba1 immunofluorescence. Correlation analyses were performed to explore relationships among FA levels, inflammatory cytokines, ROS intensity, and behavioral parameters. ResultsCompared with the NS group, mice in the CPZ+NS group exhibited significant weight loss, impaired motor coordination and memory, and markedly reduced myelin regeneration (P<0.05). FA levels and pro-inflammatory cytokines were significantly elevated in serum, corpus callosum, and spinal cord (P<0.05). FA-associated fluorescence in brain and spinal tissues, as well as ROS intensity across all tissues examined, also increased substantially (P<0.05). CPZ treatment induced pronounced microglial activation and severe demyelination in the corpus callosum (P<0.01). Both NaHSO3 and PEG-ATX@NPs effectively reduced FA accumulation in the brain and spinal cord, attenuated demyelination, suppressed microglial activation, decreased inflammatory cytokine levels, and improved motor and cognitive performance. These results confirm that CPZ induced severe demyelination accompanied by oxidative stress, neuroinflammation, and abnormal FA accumulation. Following intervention with either NaHSO3 or PEG-ATX@NPs, endogenous FA levels in the CNS were substantially reduced. Both treatments alleviated demyelination and significantly decreased the number of activated microglia. Levels of TNF-α, IL-1β, and IL-6 in serum, corpus callosum, and spinal cord were downregulated. Behavioral performance improved significantly, as evidenced by enhanced locomotor activity, better coordination, and improved memory function. These findings indicate that both FA-scavenging agents mitigate CPZ-induced biochemical and behavioral abnormalities. ConclusionThis study demonstrates that excessive endogenous FA is closely associated with cognitive impairment, inflammatory dysregulation, and demyelination in a CPZ-induced chronic demyelination mouse model. Clearing abnormally elevated FA effectively reduces neuroinflammation, suppresses microglial overactivation, decreases oxidative stress, and alleviates demyelination, ultimately improving motor and cognitive outcomes in mice. These results suggest that targeting endogenous FA represents a promising therapeutic strategy for MS and other demyelinating disorders. Further investigations are warranted to explore the long-term safety, dosage optimization, and molecular pathways involved in FA-mediated neurotoxicity.
3.Resistance of Aedes albopictus to common insecticides in Zhejiang Province, 2024
Qin-mei LIU ; Jin-na WANG ; Tian-qi LI ; Ming-yu LUO ; Zhou GUAN ; Zhen-yu GONG ; Ji-min SUN
Acta Parasitologica et Medica Entomologica Sinica 2026;33(2):96-100
Objective In order to understand the current resistance status of Aedes albopictus(Ae. albopictus) adult population to commonly used insecticides and the resistance dynamics development in Zhejiang Province and provide a theoretical basis for the scientific and rational use of hygienic insecticides. Methods Resistance determination was carried out using the diagnostic dose method(GB/T 26347-2010)recommended by WHO in the adult mosquito contact cylinder method to monitor the resistance of Ae. albopictus field populations in 11 cities and districts in Zhejiang Province in 2024. Results The monitoring result showed that adult Ae. albopictus in 11 areas were resistant or suspected resistant populations to both cis-cypermethrin and permethrin; suspected and resistant populations to the organophosphate insecticide malathion were as high as 81.82%; while suspected resistance to the carbamate insecticide residual carbofuran accounted for 45.45%, and the rest of the monitoring sites were sensitive to it. Conclusions The result suggest that the generalized resistance of Ae. albopictus populations to pyrethroids and organophosphorus insecticides in the field in Zhejiang Province needs to be highly emphasized. In future mosquito vector and mosquito-borne disease control, insecticides should be selected based on the resistance monitoring information, while following scientific guidelines for insecticide use.
4.Role of mitochondrial biogenesis in rat model of coal workers' pneumoconiosis based on PGC-1α-NRF1-TFAM signaling pathway
Mei ZHANG ; Xiaoqiang HAN ; Lulu LIU ; Yan WANG ; Xin MA ; Yu XIONG ; Huifang YANG ; Na ZHANG
Journal of Environmental and Occupational Medicine 2025;42(12):1429-1437
Background Mitochondrial biogenesis is pivotal in coal workers' pneumoconiosis fibrosis, yet the role of the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)-nuclear respiratory factor 1 (NRF1)-mitochondrial transcription factor A (TFAM) pathway inmitochondrial biogenesis remains elusive, warranting further investigation. Objective To elucidate the role of the PGC-1α-NRF1-TFAM pathway in mitochondrial biogenesis in a rat coal workers' pneumoconiosis model through in vivo and in vitro experiments. Methods (1)n vivo: twelve SPF male SD rats (200-220 g) were randomized into a control group and a coal dust group (n=6 per group). After acclimatization, the coal dust group received 1 mL 50 mg·mL−1 coal dust suspension via intratracheal instillation; the controls received saline. Lung tissues were harvested after two months for histopathology [HE, Masson, and transmission electron microscopy (TEM) ], protein and mRNA analysis, and mitochondrial DNA (mtDNA) quantification by quantitative real-time polymerase chain reaction (qPCR). (2) In vitro: rat lung type II epithelial cells (RLE-6TN) cells were exposed to coal dust (50, 100, 200, and 400 mg·L−1, 24 h). CCK-8 assay determined optimal doses. Ultrastructural changes were analyzed by TEM. Cells were transfected with OE-PGC-1α (PGC-1α overexpression) or shRNA-PGC-1α plasmids (PGC-1α knockdown), and the transfection efficiency was determined by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). The expression levels of alpah-smooth muscle actin (α-SMA), citrate synthase (CS), PGC-1α, NRF1, TFAM, and fibronectin (Fn) proteins and their corresponding mRNA were detected using Western blot and RT-qPCR, respectively. The relative content of mtDNA was determined by qPCR. Results In vivo: the control group lung samples exhibited soft, pink parenchyma, while the coal dust-exposed lungs showed blackened surfaces with soft texture. The histopathological evaluation revealed intact alveolar walls in the controls versus structural destruction, micro-nodules, and fibrotic areas in the coal dust group. After Masson staining, coal dust deposits were found surrounded by blue collagen fibers in the exposed lungs, but absent in the controls. The coal dust group displayed significant upregulation of fibrotic marker α-SMA and downregulation of mitochondrial biogenesis markers (CS, PGC-1α, NRF1, TFAM) and mtDNA compared to the controls (P<0.05). In vitro: coal dust exposure reduced cell density and induced morphological alterations. TEM revealed evenly distributed normal mitochondria in controls versus mitochondrial swelling, disrupted cristae, and reduced numbers in exposed cells. The mitochondrial biogenesis markers were elevated in the coal dust + OE-PGC-1α group compared to the coal dust + OE-NC group (P<0.05); in contrast, they were decreased in the coal dust + shRNA-PGC-1α group compared to the coal dust + shRNA-NC group (P<0.05). Compared to the control group, the expression levels of the fibrosis marker α-SMA mRNA and protein were increased in the coal dust group (P<0.05). Overexpression of PGC-1α reduced α-SMA expression, while downregulation of PGC-1α increased its expression (P<0.05). Conclusion Coal dust exposure induces mitochondrial dysfunction and pulmonary fibrosis in vivo and in vitro via the PGC-1α-NRF1-TFAM pathway dysregulation. Targeting this pathway may mitigate coal dust-induced fibrosis by restoring mitochondrial biogenesis.
5.Analysis of risk factors for short-term surgery in acute severe ulcerative colitis
Aihemaiti DILIAREMU ; Na LI ; Mei YE
Chinese Journal of Inflammatory Bowel Diseases 2025;09(1):53-58
Objective:To explore the risk factors for short-term surgery in patients with acute severe ulcerative colitis (ASUC) .Methods:A retrospective case-control study was conducted. Consecutive patients with ASUC admitted to the Department of Gastroenterology at Zhongnan Hospital of Wuhan University from January 2019 to June 2023 were enrolled. Clinical data such as general information, clinical manifestations, laboratory tests, and colonoscopy examinations were analyzed. Based on whether the patients underwent surgery within 90 days after admission, the patients were divided into short-term surgery group and short-term non-surgery group, and the differences in clinical characteristics between the two groups were compared. Univariate and multivariate Logistic regression analyses were performed to identify the risk factors for short-term surgery.Results:A total of 90 patients were included, with 58 males and 32 females, age 42.0 (30.8, 54.3) years, disease duration 1.00 (0.15, 4.25) years, body mass index (21.4 ± 3.8) kg/m 2; according to the ulcerative colitis endoscopic index of severity (UCEIS) results of 83 patients, 31 were moderate activity, and 52 were severe activity. After a follow-up period of 8.4 (3.9, 14.7) months, a total of 15 patients (16.7%) underwent surgery. Ten patients undergoing surgery within 90 days after admission were set as the short-term surgery group ( n = 10), and 5 patients undergoing surgery more than 90 days after admission and 75 receiving drug treatment were set as the short-term non-surgery group ( n = 80). Compared with the short-term non-surgery group, patients in the short-term surgery group were older, and had a higher proportion of UCEIS 7-8 points and lower remission rates induced by glucocorticoids and biological agents, with all differences being statistically significant (all P < 0.05). Univariate and multivariate Logistic regression analyses found that age ≥55 years ( P = 0.009, OR = 13.266, 95% CI: 1.922-91.548) and high baseline CRP ( P = 0.014, OR = 1.010, 95% CI: 1.002-1.019) were independent risk factors for short-term surgery in ASUC patients. Postoperative complications occurred in 4 patients, including 1 of anastomotic ulceration, 1 of ileostomy infection, and 2 of pouchitis. Conclusion:The surgery rate in ASUC patients is high, and patients who are older or have elevated CRP are more likely to undergo short-term surgery.
6.Evolution of inflammatory bowel disease: from early understanding to modern diagnosis and treatment
Na LI ; Yongmei LI ; Mei YE
Chinese Journal of Inflammatory Bowel Diseases 2025;09(4):279-285
Inflammatory bowel disease (IBD) is a kind of complex, chronic digestive disease with unclear etiology. This article systematically reviews the evolution of IBD, from early clinical descriptions to advancements in diagnostic techniques and significant developments in treatments, outlining the progression of the IBD diagnosis and treatment framework and highlighting how optimized approaches have impacted patients' quality of life. In the future, emerging technologies such as targeted immune modulation, microbiome intervention, stem cell therapy, and artificial intelligence-assisted diagnosis and treatment are expected to provide new directions and strategies for precise, personalized IBD management.
7.A prospective cohort study of the therapeutic effects of sacubitril/valsartan in peritoneal dialysis patients with refractory hypertension
Lu YANG ; Na CHEN ; Lu LI ; Lan YANG ; Caiping ZHAO ; Mei XU ; Na TIAN
Chinese Journal of Nephrology 2025;41(11):870-875
In this single-arm prospective cohort study, the aim was to evaluate the antihypertensive efficacy and safety of the angiotensinⅡreceptor-neprilysin inhibitor sacubitril/valsartan in patients with refractory hypertension (RH) undergoing peritoneal dialysis. A total of 67 peritoneal dialysis patients with regular treatment for ≥ 3 months and confirmed RH were enrolled. Sacubitril/valsartan was added to the background antihypertensive therapy and titrated according to a standardized protocol for 6 months. Data on RH control, demographic and clinical characteristics, and adverse reactions were collected before and after intervention. The mean values of valid 24 h ambulatory blood pressure recordings, nocturnal systolic blood pressure (SBP) dipping percentage, blood pressure variability parameters, and the blood pressure control rate were compared before and after treatment. Laboratory and clinical data were also compared. After a median follow-up of 8.0 (4.0, 12.5) months, 50 patients completed the study. After treatment, all blood pressure parameters significantly decreased compared with baseline. The mean values of valid 24 h SBP decreased by 9.52 mmHg ( t=4.79, P<0.001) and the mean values of valid 24 h diastolic blood pressure (DBP) decreased by 7.55 mmHg ( t=5.90, P<0.001). Day-time SBP decreased by 10.82 mmHg ( t=5.22, P<0.001) and day-time DBP by 8.41 mmHg ( t=6.28, P<0.001). Night-time SBP decreased by 6.93 mmHg ( t=2.81, P=0.007) and night-time DBP by 4.95 mmHg ( t=3.12, P=0.003). The standard deviation (SD) of 24 h-SBP ( t=2.43, P=0.018), 24 h DBP-SD ( t=3.82, P<0.001), day-time DBP-SD ( t=2.80, P=0.007), and the coefficient of variation of 24 h-DBP ( t=2.04, P=0.046) were significantly reduced. The blood pressure control rate increased from 14.90% to 44.80% ( χ2=12.89, P<0.001). During follow-up, no patient experienced acute deterioration of renal function. One case of hyperkalemia returned to normal after appropriate treatment, and no serious adverse events occurred. These findings suggest that sacubitril/valsartan effectively lowers blood pressure and improves the blood pressure control rate in peritoneal dialysis patients with RH, with favorable safety and tolerability.
8.Efficacy of Guanxinning Tablets as an adjunctive treatment for coronary heart disease complicated by insomnia in older adult patients
Na HUANG ; Xiongsheng LYU ; Jianhua MEI
Chinese Journal of Primary Medicine and Pharmacy 2025;32(2):172-176
Objective:To investigate the efficacy of Guanxinning Tablets as an adjunctive treatment for coronary heart disease complicated by insomnia in older adult patients. Methods:A total of 80 patients with coronary heart disease complicated by insomnia, admitted to The Second People's Hospital of Lishui between December 2021 and December 2023, were selected for this study. A randomized, controlled trial design was used, with patients randomly assigned to either the control group or the observation group ( n = 40/group). The control group received conventional treatment along with basic sleep-promoting interventions, while the observation group received Guanxinning Tablets in addition to the treatment provided to the control group. The treatment duration for both groups was 8 weeks. The therapeutic effects, frequency and duration of angina attacks, Pittsburgh Sleep Quality Index score, Seattle Angina Questionnaire score, serum levels of interleukin-6, tumor necrosis factor-alpha, vascular endothelial growth factor, and the incidence of adverse reactions were compared between the two groups. Results:The clinical efficacy of the observation group was significantly better than that of the control group ( Z = 2.07, P < 0.05). After treatment, the frequency and duration of angina attacks in the observation group were (1.02 ± 0.31) times/d and (1.35 ± 0.27) min, both of which were significantly lower and shorter than those in the control group [(1.54 ± 0.40) times/d, (1.71 ± 0.36) min, t = -6.50, -5.06, both P < 0.05]. The Pittsburgh Sleep Quality Index score in the observation group was (5.93 ± 1.28), which was significantly lower than that in the control group [(7.33 ± 2.05), t = -3.66, P < 0.05]. The Seattle Angina Questionnaire scores for all dimensions in the observation group were higher than those in the control group ( t = 2.81, 2.30, 2.97, 4.76, 4.24, all P < 0.05). The levels of interleukin-6 and tumor necrosis factor-alpha in the observation group were (13.48 ± 3.60) mg/L and (15.53 ± 3.83) μg/L, respectively, both of which were significantly lower than those in the control group [(16.26 ± 4.51) mg/L, (20.38 ± 3.92) μg/L, t = -3.05, -5.60, both P < 0.05]. The vascular endothelial growth factor level in the observation group was (128.26 ± 16.67) ng/L, which was significantly higher than that in the control group [(105.78 ± 14.35) ng/L, t = 6.46, P < 0.05]. There was no significant difference in the incidence of adverse reactions between the two groups ( P > 0.05). Conclusions:Guanxinning Tablets, as an adjunctive treatment for coronary heart disease complicated by insomnia, can significantly improve outcomes in older adults by alleviating angina symptoms, enhancing sleep quality, and reducing inflammatory responses, without increasing the incidence of drug-related adverse reactions.
9.Analysis of risk factors for brucellar spondylitis
Na-na ZHAO ; Mei-gang ZHANG ; Xiang-lei CHEN ; Li ZHAO ; Cui-ping WU
Chinese Journal of Zoonoses 2025;41(3):284-289
The aim of this study was to investigate the risk factors for brucellar spondylitis.Electronic medical record data for patients with brucellosis at Yidu Central Hospital in Weifang City were retrospectively collected from January 2018 to April 2024,including general data,clinical characteristics,and laboratory examinations.The patients were divided into a spinal in-volvement group and a no spinal involvement group.The risk factors for brucellar spondylitis were determined through multi-factorial logistic regression model analysis.Of the 124 patients with brucellosis,59 had brucellar spondylitis,and 65 had bru-cellosis alone.There were more patients with age ≥55 years(x2=17.71),time from onset to diagnosis ≥30 days(x2=26.17),and low back pain(x2=52.71)in the spinal involvement group than in the group without spinal involvement,and the difference was statistically significant(all P<0.001);there were more patients with headaches in the group without spinal in-volvement than in the group with spinal involvement,and the difference was statistically significant(x2=8.34,P<0.05).and there were more patients in the spinal involvement group with neutrophil percent(NEU%)(t=2.94),platelet count(PLT)(t=122.00),blood sedimentation rate(ESR)(Z=-6.74),C-reactive protein(CRP)(Z=-5.74),and interleukin-6(IL-6)(Z=-2.08)were higher in the spine-involved group than in the group without spine-involvement,and the differences were all statistically significant(all P<0.05);Lactate dehydrogenase was significantly lower in the spine-involved group(LDH)than the group without spinal involvement(t=-2.04,P<0.042).A multifactorial logistic regression analysis indicated that a du-ration of out-of-hospital symptoms ≥30 days(OR=6.265,95%CI 1.181-33.241),symptoms of low back pain(OR=14.885,95%CI 3.144-70.472),elevated PLT(OR=1.013,95%CI 1.004-1.023),and elevated ESR(OR=1.053,95%CI 1.008-1.100)were risk factors for brucellar spondylitis(all P<0.05).The optimal cut-off values for ROC analysis were PLT>278.5 ×109/L(sensitivity 89.2%,specificity 59.3%)and ESR>16.5 mm/h(sensitivity 69.2%,specificity of 86.4%);using both PLT and ESR for diagnosis yielded an AUROC of 0.891(95%CI 0.831-0.950),a sensitivity of 86.2%,and a specificity of 84.7%.When patients with brucellosis present with symptoms of low back pain,a time from onset to diagnosis of ≥30 days,and markedly elevated ESR and PLT,lumbar magnetic resonance examination is recommended to rule out brucellar spondylitis,to enable early diagnosis and timely treatment,improve patient prognosis,shorten illness duration,and improve patient quality of life.
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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