1.Fibroblast Growth Factors in Parkinson’s Disease: Multi-target Neuroprotective Mechanisms Involving Neuroinflammation, Cellular Stress, and Ferroptosis
Hui WANG ; Zi-Gui ZHOU ; Teng-Teng HAN ; Chang-Zhi YANG ; Xue-Wen TIAN
Progress in Biochemistry and Biophysics 2026;53(4):855-874
Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by the selective loss of dopaminergic neurons in the substantia nigra pars compacta and the pathological accumulation ofα‑synuclein. Although extensive progress has been made in elucidating its pathogenesis, current therapeutic approaches remain largely symptomatic, and effective disease-modifying treatments are still unavailable. Increasing evidence indicates that PD is driven by the interaction of multiple pathological processes, including neuroinflammation, iron homeostasis dysregulation and ferroptosis, endoplasmic reticulum (ER) stress, mitochondrial dysfunction, oxidative stress, and impaired protein homeostasis, which together contribute to neuronal vulnerability and degeneration. Fibroblast growth factors (FGFs) comprise a family of 22 ligands that play important roles in neural development, stress responses, metabolic regulation, and the maintenance of nervous system homeostasis. Recent studies have shown that several FGF family members, such as FGF1, FGF2, FGF9, and FGF21, exert neuroprotective effects in cellular and animal models of PD. These effects include the regulation of inflammatory responses, oxidative stress, iron homeostasis, cellular stress adaptation, and neuronal survival. Compared with therapeutic strategies targeting a single pathogenic pathway, FGFs appear to influence multiple disease-related processes, suggesting their potential relevance to the complex pathophysiology of PD. Experimental evidence indicates that altered FGF signaling may contribute to dopaminergic neuron dysfunction through the coordinated regulation of several interconnected mechanisms. FGFs have been reported to modulate neuroinflammation by affecting the activation of microglia and astrocytes, thereby influencing the inflammatory environment in the central nervous system. In addition, FGFs are involved in the regulation of iron homeostasis and ferroptosis, partly through antioxidant signaling pathways associated with NRF2, SLC7A11, and GPX4. Moreover, FGFs can alleviate ER stress and mitochondrial dysfunction by activating intracellular signaling pathways such as PI3K/AKT, AMPK-PGC-1α, as well as SIRT1-dependent programs, which support cellular energy metabolism and redox balance. Recent advances in single-cell and spatial transcriptomic studies further suggest that FGF signaling is not limited to neuron-intrinsic mechanisms but also involves interactions among different glial cell types. Altered FGF ligand-receptor communication between astrocytes and oligodendrocytes has been observed in PD models and is associated with increased susceptibility of dopaminergic neurons to oxidative stress and ferroptosis. These findings indicate that the biological effects of FGFs are influenced by cell type and disease stage and may vary under different pathological conditions. In this review, we summarize recent progress in understanding the roles of FGF family members in PD, with a focus on their involvement in iron homeostasis dysregulation and ferroptosis, neuroinflammation, cellular stress responses, and neuronal protection and regeneration. By integrating current evidence, this review aims to provide a clearer understanding of how FGFs participate in PD pathogenesis and to offer a theoretical basis for future studies exploring their potential value in disease-modifying therapeutic strategies.
2.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.
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.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.
5.Clinical effects of Supplemented Buyang Huanwu Decoction on postoperative patients with lumbar vertebral fracture complicated with spinal cord injury due to Qi Deficiency and Blood Stasis Pattern
Jia-man YANG ; Tong LIU ; De-hui FAN ; Mei-yi SU ; Ying LIN ; Man-guang LIANG ; Zhi-wen OU ; Shun-cong ZHANG
Chinese Traditional Patent Medicine 2025;47(11):3630-3634
AIM To explore the clinical effects of Supplemented Buyang Huanwu Decoction on postoperative patients with lumbar vertebral fracture complicated with spinal cord injury due to Qi Deficiency and Blood Stasis Pattern.METHODS One hundred and twenty patients were randomly assigned into control group(60 cases)for 6-week intervention of conventional treatment,and observation group(60 cases)for 6-week intervention of both Supplemented Buyang Huanwu Decoction and conventional treatment.The changes in clinical effects,TCM syndrome scores,spinal cord conduction signals(SEP amplitude,MEP amplitude),serum neurotrophic factors(NGF,IGF-1,BDNF),coagulation and inflammatory indices(PT,APTT,TNF-α,IL-1 β)and incidence of adverse reactions were detected.RESULTS The observation group demonstrated higher total effective rate than the control group(P<0.05).After the treatment,the two groups displayed decreased TCM syndrome scores,TNF-α,IL-1β(P<0.05),increased spinal cord conduction signals,coagulation and inflammatory indices(P<0.05),and shortened PT,APTT(P<0.05),especially for the observation group(P<0.05).No significant difference in incidence of adverse reactions was found between the two groups(P>0.05).CONCLUSION For the patients with lumbar vertebral fracture complicated with spinal cord injury due to Qi Deficiency and Blood Stasis Pattern,Supplemented Buyang Huanwu Decoction can safely and effectively promote neurological function recovery.
6.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.
7.Mechanism by which sanguis draconis flavones regulating ROS/TXNIP pathway-mediated pyroptosis to ameliorate cerebral ischemia-reperfusion injury in rats
Chao-Xia ZHU ; Zhi-Ying LI ; Xiao-Fei LÜ ; Qian ZHAO ; Bao-Cang CHENG ; Hui-Jie YANG ; Li-Ping ZHOU ; Li-Min ZENG
Acta Anatomica Sinica 2025;56(6):673-680
Objective To explore the mechanism by which the sanguis draconis flavones(SDF)regulates the reactive oxygen species(ROS)/thioredoxin-interacting protein(TXNIP)pathway to mediate cell pyroptosis and improve cerebral ischemia-reperfusion injury(CIRI)in rats.Methods The experimental rats were randomly divided into the control group(Ctrl),the CIRI group,the low-dose SDF group(SDF-L),the high-dose SDF group(SDF-H),and the SDF-H+ROS/TXNIP pathway activator,trimethylamine oxide(TMAO)group(SDF-H+TMAO).Among them,except for the control group,the remaining rats all needed to establish the CIRI rat model by the modified suture method.Zea Longa scoring was performed on rats from each group.ELISA was used to detect the levels of serum inflammatory factors interleukin(IL)-1β,IL-18 and oxidative stress-related factors superoxide dismutase(SOD),malondialdehyde(MDA),glutathione peroxidase(GSH-Px).Flow cytometry was used to measure the ROS levels.Cerebral edema was detected.Cerebral infarction was detected by 2,3,5-triphenyl tetrazolium chloride(TTC)staining.HE staining was used to detect the pathological changes of brain tissue.Immunohistochemistry was used to detect the expression of pyrolytic effector protein dermolin D(GSDMD).Western blotting was used to detect the expression of proteins related to the ROS/TXNIP pathway.Results Compared with the control group,a large area of cerebral infarctions were observed in the brain tissue of the CIRI group,accompanied by mild hemorrhage and obvious infiltration of inflammatory cells.Neuronal cells underwent degeneration and necrosis,with sparse and disordered arrangement.The phenomena of nuclear condensation and nucleolus lysis were obvious.The Zea Longa score,cerebral infarction volume,brain tissue water content,levels of IL-1β,IL-18,ROS,MDA,and the expressions of GSDMD,TXNIP,nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3),apoptosis-related punctate protein(ASC),and Caspase-1 increased,while the activities of SOD and GSH-Px decreased(P<0.05).Compared with the CIRI group,the pathological damage of brain tissues in the SDF-L group and the SDF-H group was significantly improved.The Zea Longa score,cerebral infarction volume,brain tissue water content,levels of IL-1β,IL-18,ROS,MDA,and the expressions of GSDMD,TXNIP,NLRP3,ASC,and Caspase-1 decreased.The activities of SOD and GSH-Px increased(P<0.05);TMAO treatment partially reversed the improvement effect of SDF on CIRI in rats.Conclusion SDF ameliorates cerebral CIRI in rats by inhibiting ROS/TXNIP pathway-mediated pyroptosis.
8.Mechanism of Ganoderma lucidum polysaccharides promoting myelin regeneration in demyelinated mice induced by cuprizone
Yan-qing LI ; Xiao-hui LI ; Qing WANG ; Li-juan SONG ; Li-zhi YANG ; Han-bin WANG ; Bao-guo XIAO ; Cun-gen MA
Chinese Pharmacological Bulletin 2025;41(7):1265-1273
Aim To explore the mechanism of Gano-derma lucidum polysaccharides(GLPS)promoting my-elin repair and regeneration in mice with chronic demy-elination induced by cuprizone(CPZ).Methods A total of 40 C57BL/6 mice were randomly divided into four groups:Normal+NS,Normal+GLPS,CPZ+NS and CPZ+GLPS.A chronic demyelination model was established using 0.2%CPZ.Open field and elevated plus maze tests were performed to observe the behavior-al changes in the mice.Immunofluorescence staining and Western blot were used to detect changes in myelin basic protein expression in the corpus callosum.ELISA was performed to measure the levels of TNF-α,IL-6,IL-1β and IL-10 in brain homogenates.Immunofluo-rescence staining was also used to observe the expres-sion of ionized calcium binding adapter molecule 1(Iba1)and neural-glial antigen 2(NG2).RT-qPCR and Western blot were conducted to assess the mRNA and protein expression levels of MBP,iNOS,COX-2,JAK2 and STAT3.Results Mice in the CPZ+NS group showed a significant decrease in body weight,cognitive behavior abnormalities,and impaired myelin regeneration.The expression of pro-inflammatory fac-tors increased,while anti-inflammatory factors de-creased.Additionally,Iba1 and NG2 expression in-creased,and the JAK2/STAT3 signaling pathway was activated.After GLPS intervention,the mouse body weight increased,myelin regeneration occurred,cogni-tive behavior was improved,the expression of inflamma-tory factors decreased,anti-inflammatory factors in-creased,NG2 expression was further elevated,and the proliferation of microglia as well as the activation of the JAK2/STAT3 signaling pathway was inhibited.Conclu-sions GLPS can improve cognitive behavior abnormali-ties and inflammatory responses in chronic demyelinated mice by inhibiting the JAK2/STAT3 signaling pathway,thereby promoting myelin repair and regeneration.
9.Establishment of a rapid fluorescence immunochromatographic assay for avian influenza virus subtype H5N6
Hui LI ; Li LIU ; Yi-sheng ZHOU ; Zhi-hong ZHANG ; Qian-qian SI ; Ru-xia WANG ; Zhi-qiang DENG ; Yi-bing FAN ; Liang JIN ; Jie SUN ; Chun-hua YANG
Chinese Journal of Zoonoses 2025;41(3):243-248,283
In view of the characteristics of H5N6 subtype avian influenza virus(AIV)that it has both high pathogenicity and the risk of cross-species transmission,posing a serious threat to the poultry farming industry and public health security,in order to effectively prevent and control the spread of H5N6 avian influenza,a rapid,sensitive and specific detection technolo-gy was established in this study.The specific monoclonal antibodies against the neuraminidase N6 protein of avian influenza A virus subtype H5N6 were obtained through hybridoma and monoclonal antibody technology.These antibodies were coupled and labeled with carboxyl-functionalized fluorescent quantum dots,along with previously prepared specific antibodies against the hemagglutinin H5 protein.A rapid fluorescence immunochromatographic detection method for the H5N6 subtype of avian influ-enza virus was established according to the principle of double-antibody sandwich immunochromatography.This method a-chieved a detection sensitivity of 1 ng/mL for recombinant hemagglutinin H5 subtype protein and 0.1 ng/mL for recombinant neuraminidase N6 subtype protein.Moreover,the method exhibited no cross-reactivity with other influenza subtypes or patho-gens,such as Newcastle disease(ND),infectious bronchitis(IB),and infectious laryngotracheitis(ILT),thus demonstrating good specificity.The method effectively identified the highly pathogenic avian influenza virus H5 subtype and directly distin-guished the H5N6 subtype with good accuracy.The fluorescent quantum dot immunochromatographic typing detection method established herein met the sensitivity,specificity,and accuracy requirements for H5N6 subtype detection,and can be further used for rapid detection of the H5 and H5N6 subtypes of avian influenza virus.
10.Epidemiological and genomic characteristics of linezolid-resistant Enterococci iso-lated from livestock farms in Changsha
Jianqin LIU ; Jianchao ZHANG ; Zhi CHEN ; Hui YANG ; Honggang ZHU ; Liang QI ; Xiao-jun CHEN
Chinese Journal of Veterinary Science 2025;45(5):978-986
To investigate the antimicrobial resistance of Enterococci isolated from 596 anal swabs,feces and environmental samples were collected from pig,cattle,chicken and quail farms in Chang-sha,Hunan Province,Enterococci were isolated and identified by mass spectrometry.The minimum inhibitory concentrations(MICs)of 10 antimicrobial agents were determined by AGAR diffusion method.Whole genome sequencing(WGS)was used to detect the distribution of multilocus se-quence typing(ST),drug resistance genes and virulence genes.A total of 272 strains of Enterococ-cus were isolated(45.6%).The isolates were resistant to cefoxitin(68.9%)and cefotiofur(58.5%),followed by trimethoprim/sulfamethoxazole(52.2%),vancomycin(4.4%),and linezolid(13.6%).In this study,six linezolid highly resistant Enterococci isolates were analyzed by whole genome sequencing to explore the transmission mechanism of linezolid resistance because linezolid is forbidden to be used in aquaculture.ST403(4/6),ST16(1/6)and ST476(1/6)were the most common ST types,which all originated from the same farm.Three oxazolidinone resistance genes(cfr,poxtA and optrA)were found in all 21 strains.One strain(Ecc60)carried all three oxazo-lidinone resistance genes,but none of them were located on the plasmid.tet(M),aph(3')-Ⅲ,and lsa(A)were found in all six Enterococcus isolates.Interestingly,the present study is the first to i-dentify enterococci carrying the optrA gene in quail fecal samples.The analysis of the genetic envi-ronment of oxazolidinone resistance genes showed that the genetic environment of cfr(D),poxtA and optrA of isolates from the same farm was similar.A total of 19 virulence genes were detected in 6 isolates,of which 12 genes(ElrA,SrtA,ace,agg,cCF10,cOB1,cad,camE,ebpA,ebpC,efaAfs,tpx)were carried by all 6 isolates,and the types of virulence genes in strains from the same farm were extremely similar.The results showed that the drug resistance of Enterococci iso-lated from the fish farms in Changsha was serious,and the resistance rate to linezolid,which was prohibited in the fish farms,was high.The oxazolidinone resistance gene loci were accompanied by other resistance genes,especially the florfenicol resistance gene(FexA),which may be related to the abuse of florfenicol in the fish farms.


Result Analysis
Print
Save
E-mail