JOURNAL OF ASIA-PACIFIC ENTOMOLOGY
·
2014
·
IF 0.875
Xin Chao Liu,Xiao Nan Lu,Qi Zhi Liu,Zhi Long Liu
Water-distilled essential oil from the dried bulbs of Allium chinense (Liliaceae) was analyzed by gas chromatography–mass spectrometry (GC–MS). Eighteen compounds, accounting for 98.4% of the total oil, were identified and the main components of the essential oil of A. chinense were methyl allyl trisulfide (30.7%), dimethyl trisulfide (24.1%), methyl propyl disulfide (12.8%) and dimethyl disulfide (9.6%) followed by methyl allyl disulfide (3.4%) and methyl propyl trisulfide (3.6%). The essential oil exhibited contact toxicity against the booklice ( Liposcelis bostrychophila ) with an LC 50 value of 441.8 μg/cm 2 while the two major constituents, dimethyl trisulfide and methyl propyl disulfide had LC 50 values of 153.0 μg/cm 2 and 738.0 μg/cm 2 against the booklice, respectively. The essential oil of A. chinense possessed strong fumigant toxicity against the booklice with an LC 50 value of 186.5 μg/l while methyl allyl trisulfide (LC 50 = 90.4 μg/l) and dimethyl trisulfide (LC 50 = 114.2 μg/l) exhibited stronger fumigant toxicity than methyl propyl disulfide (LC 50 = 243.4 μg/l) and dimethyl disulfide (LC 50 = 340.8 μg/l) against the booklice. The results indicated that the essential oil and its major constituents have potential for development into natural insecticides or fumigants for control of insects in stored grains.
研究领域:
植物学
·
昆虫学
·
农药学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF ACAROLOGY
·
2024
·
IF 0.9
Qiao Teng,Minghui Zou,Qiqi Xue,Qiqi Zhang,Ting Liu,Junjie Guo,Yuanyuan Li,Jinhong Zhao
This study was designed to evaluate the acaricidal effect and the mode of action of lemongrass essential oil (LEO) against Aleuroglyphus ovatus. Contact and fumigant mortality indicated that LEO had higher acaricidal activities at a low concentration, and the acaricidal action of LEO was significantly more effective by contact effects than by fumigant bioassay. Repellent rate against A. ovatus at different concentrations of LEO increased with application time. Observation on the toxic symptoms revealed that almost all mites were in immobilized type (IM type) in 30 min, but the symptom of knock-down type (KD type) appeared later. Cuticles of mites killed by LEO exhibited obvious colour change and deformation. Detoxification enzyme activity assay showed that glutathione S-transferase (GST) activity increased in mites treated by LEO compared to the controls. LEO increased catalase (CAT) activity of A. ovatus but inhibited superoxide dismutase (SOD) after 20 h. LEO also increased nitric oxide synthetase (NOS) and inhibited acetylcholine esterase (AChE) activities. Moreover, LEO acted as a fast-acting neurotoxin on A. ovatus. Our results suggest that LEO has an acaricidal potential and is a promising agent in control of A. ovatus.
研究领域:
植物化学
·
害虫管理
·
昆虫生理学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Arthropod-Borne Diseases
·
2012
·
IF 0
Wei Xiang Zhu,Kun Zhao,Sha Sha Chu,Zhi Long Liu
Background: The efficacy of essential oil of Chenopodium ambrosioides flowering aerial parts and its three main active ingredients was evaluated against Blattella germanica male adults. Methods: Composition of essential oil was determined by GC-MS. Topical application bioassay was used to evaluate contact toxicity of essential oil and three main components. Fumigant toxicity of essential oil and its main components was measured using a sealed space method. Results: Twenty-two components were identified in the essential oil and the main components were ( Z )-ascaridole (29.7%), isoascaridole (13.0%), ρ-cymene (12.7%) and piperitone (5.0%). The essential oil and ( Z )-ascaridole, isoascaridole and ρ-cymene possessed fumigant toxicity against male German cockroaches with LC 50 values of 4.13, 0.55, 2.07 and 6.92 mg/L air, respectively. Topical application bioassay showed that all the three compounds were toxic to male German cockroaches and ( Z )-ascaridole was the strongest with a LD 50 value of 22.02 μg/adult while the crude oil with a LD 50 value of 67.46 μg/adult. Conclusion: The essential oil from Chinese C. ambrosioides and its three main active ingredients may be explored as natural potential insecticides in the control of cockroaches.
研究领域:
昆虫学
·
植物化学
·
天然产物研究
✓ 已验证
DOI
PubMed
MOLECULES
·
2013
·Vol. 18
·期 9
·10733-10746
·
IF 2.428
Xin Chao Liu,Yin Ping Li,He Qin Li,Zhi Wei Deng,Ligang Zhou,Zhi Long Liu,Shu Shan Du
The aim of this research was to determine the chemical composition and insecticidal and repellent activity of the essential oil ofArtemisia rupestrisL. aerial parts against the bookliceLiposcelis bostrychophilaBadonnel and isolation of insecticidal and repellent constituents from the essential oil. The essential oil ofA. rupestriswas obtained by hydrodistillation and analyzed by GC-MS. A total of 30 components of the essential oil ofA. rupestriswas identified and the principal compounds in the essential oil were α-terpinyl acetate (37.18%), spathulenol (10.65%), α-terpineol (10.09%), and linalool (7.56%), followed by 4-terpineol (3.92%) and patchoulol (3.05%). Based on bioactivity-guided fractionation, the four active constituents were isolated from the essential oil and identified as α-terpineol, α-terpinyl acetate, 4-terpineol and linalool. The essential oil ofA. rupestrisexhibited contact toxicity againstL. bostrychophilawith LD50value of 414.48 µg/cm2. α-Terpinyl acetate (LD50= 92.59 µg/cm2) exhibited stronger contact toxicity against booklice than α-terpineol (LD50= 140.30 µg/cm2), 4-terpineol (LD50= 211.35 µg/cm2), and linalool (LD50= 393.16 µg/cm2). The essential oil ofA. rupestris(LC50= 6.67 mg/L air) also possessed fumigant toxicity againstL. bostrychophilawhile the four constituents, 4-terpineol, α-terpineol, α-terpinyl acetate and linalool had LC50values of 0.34, 1.12, 1.26 and 1.96 mg/L air, respectively. α-Terpinol and α-terpinyl acetate showed strong repellency againstL. bostrychophila, while linalool and 4-terpinol exhibited weak repellency. The results indicate that the essential oil ofA. rupestrisaerial parts and its constituent compounds have potential for development into natural insecticides or fumigants as well as repellents for control of insects in stored grains.Keywords:Liposcelis bostrychophila;Artemisia rupestris;contact toxicity;fumigant toxicity;repellency;essential oil composition
研究领域:
昆虫学
·
植物化学
·
害虫防治
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2023
·Vol. 24
·期 18
·14211
·
IF 5.6
Jie Li,Ning Han,Yangyang Li,Feifei Zhao,Wenguang Xiong,Zhenling Zeng
Streptococcus suisis an emerging zoonotic pathogen that can cause fatal diseases such as meningitis and sepsis in pigs and human beings. The overuse of antibiotics is leading to an increased level of resistance inS. suis, and novel antimicrobial agents or anti-virulence agents for the treatment of infections caused byS. suisare urgently needed. In the present study, we investigated the antibacterial activity, mode of action and anti-virulence effects of floxuridine againstS. suis. Floxuridine showed excessive antibacterial activity againstS. suisboth in vivo and in vitro; 4 × MIC of floxuridine could killS. suiswithin 8 h in a time–kill assay. Meanwhile, floxuridine disrupted the membrane structure and permeability of the cytoplasmic membrane. Molecular docking revealed that floxuridine and SLY can be directly bind to each other. Moreover, floxuridine effectively inhibited the hemolytic capacity and expression levels of the virulence-related genes ofS. suis. Collectively, these results indicate that the FDA-approved anticancer drug floxuridine is a promising agent and a potential virulence inhibitor againstS. suis.Keywords:floxuridine;Streptococcus suis;mode of action;anti-virulence
研究领域:
微生物学
·
药理学
·
传染病学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2024
·
IF 3.9
Xuemeng Ji,Dancai Fan,Jin Wang,Bowei Zhang,Yaozhong Hu,Huan Lv,Jing Wu,Yi Sun,Jingmin Liu,Yan Zhang,Shuo Wang
Cronobacter sakazakii poses a significant threat, particularly to neonates and infants. Despite its strong pathogenicity, understanding of C. sakazakii biofilms and their role in infections remains limited. This study investigates the roles of HmsP and c-di-GMP in biofilm formation and identifies key genetic and proteomic elements involved. Gene knockout experiments reveal that HmsP and c-di-GMP are linked to biofilm formation in C. sakazakii. Comparative proteomic profiling identifies the lysozyme inhibitor protein LprI, which is downregulated in hmsP knockouts and upregulated in c-di-GMP knockouts, as a potential biofilm formation factor. Further investigation of the lprI knockout strain shows significantly reduced biofilm formation and decreased virulence in a rat infection model. Additionally, LprI is demonstrated to bind extracellular DNA, suggesting a role in anchoring C. sakazakii within the biofilm matrix. These findings enhance our understanding of the molecular mechanisms underlying biofilm formation and virulence in C. sakazakii, offering potential targets for therapeutic intervention and food production settings.
研究领域:
微生物学
·
分子生物学
·
感染病学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2025
·
IF 7.7
Yamin Shen,Yue Li,Yingying Quan,Wenjie Jin,Yuxin Wang,Baobao Liu,Yang Wang
s Streptococcus suis ( S. suis ) represents a significant bacterial pathogen, with its zoonotic transmission from infected or deceased pigs to humans posing a serious threat to public health. The type IV secretion system (T4SS), a critical virulence factor of S. suis , is tightly regulated by diverse environmental conditions. This study explores the influence of environmental variables, including temperature, incubation duration, monosaccharides, and metal ions, on the regulation of T4SS in S. suis and its associated pathogenicity. Results revealed that T4SS expression peaked during the stabilization phase at 37 °C, with galactose markedly enhancing T4SS expression relative to glucose. Zinc ions specifically enhanced the expression of the T4SS effector SspA among various metal ions. Moreover, zinc exposure significantly augmented both T4SS and virulence gene expression capabilities in S. suis . Zinc-treated S. suis exhibited enhanced adhesion, invasion, and colonization capacity in Hep-2 cells, Raw264.7 cells, and mouse models. These findings provide a deeper comprehension of the environmental modulation of T4SS in S. suis , paving the way for advanced studies into its mechanisms of pathogenicity.
研究领域:
微生物学
·
感染病学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Fishes
·
2023
·Vol. 8
·期 3
·122
·
IF 2.3
Shengping Li,Shun Zhou,Qiuhong Yang,Yongtao Liu,Yibin Yang,Ning Xu,Xiaohui Ai,Jing Dong
Antibiotics were the main fishery drugs for treatingAeromonas hydrophila(A. hydrophila) infection, which would generate selective pressure and result in the appearance of antibiotic-resistant bacteria. The bacterial quorum sensing (QS) system provides a new alternative strategy againstA. hydrophilainfection. QS inhibitors can reduce bacterial virulence behaviors by disrupting QS, which has no effect on bacterial growth. Therefore, we studied the effect of cinnamaldehyde from a natural plant extract on the QS ofA. hydrophilaaiming to reduce its pathogenicity. The efficacy of cinnamaldehyde againstA. hydrophilawas evaluated from various aspects, including the effects on aerolysin, lipase, protease, swarming motility, biofilm formation, acyl-homoserine lactones (AHLs), and QS-related genes. Moreover, the therapeutic effect of cinnamaldehyde in vitro and in vivo was studied. The results showed that cinnamaldehyde could decrease the virulence phenotypes ofA. hydrophilaregulated by QS. Moreover, the transcriptions of related genes (aerA,ahyR, andahyI) were downregulated following the addition of cinnamaldehyde. The in vitro and in vivo therapeutic assays show that cinnamaldehyde could reduce the aerolysin-mediated A549 cell injury and increase the survival rate of crucian carp infected withA. hydrophila. These results indicate that cinnamaldehyde would be a candidate QS inhibitor againstA. hydrophilainfection.Keywords:Aeromonas hydrophila;quorum sensing;cinnamaldehyde;virulence;biofilm
研究领域:
微生物学
·
水产养殖
·
感染生物学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Microbiology
·
2023
·
IF 5.2
Tang Miran,Huang Zeyu,Zhang Xiaodong,Kong Jingchun,Zhou Beibei,Han Yijia,Zhang Yi,Chen Lijiang,Zhou Tieli
Introduction: Phage is promising for the treatment of hypervirulent Klebsiella pneumoniae (hvKP) infections. Although phage resistance seems inevitable, we found that there still was optimization space in phage therapy for hvKP infection.Methods: The clinical isolate K. pneumoniae FK1979 was used to recover the lysis phage ΦFK1979 from hospital sewage. Phage-resistant bacteria were obtained on LB agar and used to isolate phages from sewage. The plaque assay, transmission electron microscopy (TEM), multiplicity of infection test, one-step growth curve assay, and genome analysis were performed to characterize the phages. Colony morphology, precipitation test and scanning electron microscope were used to characterize the bacteria. The absorption test, spot test and efficiency of plating (EOP) assay were used to identify the sensitivity of bacteria to phages. Whole genome sequencing (WGS) was used to identify gene mutations of phage-resistant bacteria. The gene expression levels were detected by RT-qPCR. Genes knockout and complementation of the mutant genes were performed. The change of capsules was detected by capsule quantification and TEM. The growth kinetics, serum resistance, biofilm formation, adhesion and invasion to A549 and RAW 264.7 cells, as well as G. mellonella and mice infection models, were used to evaluate the fitness and virulence of bacteria.Results and discussion: Here, we demonstrated that K2 capsule type sequence type 86 hvKP FK1979, one of the main pandemic lineages of hvKP with thick capsule, rapidly developed resistance to a K2-specific lysis phage ΦFK1979 which was well-studied in this work to possess polysaccharide depolymerase. The phage-resistant mutants showed a marked decrease in capsule expression. WGS revealed single nucleotide polymorphism (SNP) in genes encoding RfaH, galU, sugar glycosyltransferase, and polysaccharide deacetylase family protein in the mutants. RfaH and galU were further identified as being required for capsule production and phage sensitivity. Expressions of genes involved in the biosynthesis or regulation of capsule and/or lipopolysaccharide significantly decreased in the mutants. Despite the rapid and frequent development of phage resistance being a disadvantage, the attenuation of virulence and fitness in vitro and in vivo indicated that phage-resistant mutants of hvKP were more susceptible to the immunity system. Interestingly, the newly isolated phages targeting mutants changed significantly in their plaque and virus particle morphology. Their genomes were much larger than and significantly different from that of ΦFK1979. They possessed much more functional proteins and strikingly broader host spectrums than ΦFK1979. Our study suggests that K2-specific phage has the potential to function as an antivirulence agent, or a part of phage cocktails combined with phages targeting phage-resistant bacteria, against hvKP-relevant infections.
研究领域:
微生物学
·
分子生物学
·
传染病学
·
基因组学
·
噬菌体疗法
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Cellular and Infection Microbiology
·
2025
·
IF 4.8
Xueyao Fang,Yanhui Chen,Longhua Hu,Shumin Gu,Junqi Zhu,Yaping Hang,Xingwei Cao,Yanping Xiao,Hong Luo,Chuwen Zhao,Lianhua Xiao,Qiaoshi Zhong
Indole, a crucial bacterial signaling molecule, plays a fundamental role in regulating various physiological processes within bacteria, including growth, acid tolerance, biofilm development, motility, and other cellular functions. Its regulatory influence extends beyond indole-producing bacteria, significantly impacting the physiological activities in non-indole-producing species. In this study, we demonstrate that indole enhances the pathogenicity and viability of Klebsiella pneumoniae using the Galleria mellonella infection model and serum killing assay. Concurrently, indole has varying effects on biofilm formation in K. pneumoniae, with some strains showing enhanced biofilm formation ability. To elucidate the underlying molecular mechanisms, transcriptome analysis revealed that indole exposure in K. pneumoniae led to the upregulation of genes associated with pili formation and iron acquisition systems, while simultaneously inducing oxidative stress responses. Additionally, our analysis uncovered extensive metabolic remodeling. Specifically, we observed significant upregulation of genes involved in simple carbohydrate utilization pathways, including those responsible for galactose, mannose, and maltose metabolism, as well as enhanced expression of genes associated with pyrimidine biosynthesis. These findings collectively indicate that indole enhances the intestinal colonization and pathogenicity of K. pneumoniae primarily by modulation of fimbriae expression and metabolic pathway regulation.
研究领域:
微生物学
·
分子生物学
·
感染病学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Immunology
·
2023
·
IF 7.3
Zhang Lishan,Sun Lina,Srinivasan Ramanathan,Lin Meizhen,Gong Lanqing,Lin Xiangmin
Bacterial AraC is a transcription factor family that initiates transcription by recruiting RNA polymerase to the promoter and directly regulating various bacterial phenotypes. It also directly regulates various bacterial phenotypes. However, how this transcription factor regulates bacterial virulence and affects host immunity is still largely unknown. In this study, deleting the orf02889 (AraC-like transcription factor) gene in virulent Aeromonas hydrophila LP-2 affected several important phenotypes, such as increasing biofilm formation and siderophore production abilities. Moreover, Δorf02889 also significantly decreased the virulence of A. hydrophila and has promising attenuated vaccine potential. To better understand the effects of orf02889 on biological functions, a data independent acquisition (DIA)-based quantitative proteomics method was performed to compare the differentially expressed proteins between Δorf02889 and the wild-type strain in extracellular fractions. The following bioinformatics analysis suggested that ORF02889 may regulate various metabolic pathways, such as quorum sensing and ATP binding cassette (ABC) transporter metabolism. Moreover, 10 selected genes from the top 10 decreasing abundances in proteomics data were deleted, and their virulence to zebrafish was evaluated, respectively. The results showed that ΔcorC, Δorf00906, and Δorf04042 significantly reduced bacterial virulence. Finally, the following chromatin immunoprecipitation and polymerase chain reaction (ChIP-PCR) assay validated that the promoter of corC was directly regulated by ORF02889. Overall, these results provide insight into the biological function of ORF02889 and demonstrate its inherent regulatory mechanism for the virulence of A. hydrophila.
研究领域:
微生物学
·
蛋白质组学
·
分子生物学
·
传染病学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Cell Reports
·
2024
·
IF 7.5
Xia Li,Shihao Song,Xiaohan Kong,Xiayu Chen,Zhuoxian Zhao,Zizi Lin,Yantao Jia,Yong Zhang,Hai-Bin Luo,Qiao-Ping Wang,Lian-Hui Zhang,Wei Qian,Yinyue Deng
Quorum sensing (QS) is a cell-to-cell communication mechanism mediated by small diffusible signaling molecules. Previous studies showed that RpfR controls Burkholderia cenocepacia virulence as a cis -2-dodecenoic acid (BDSF) QS signal receptor. Here, we report that the fatty acyl-CoA ligase DsfR (BCAM2136), which efficiently catalyzes in vitro synthesis of lauryl-CoA and oleoyl-CoA from lauric acid and oleic acid, respectively, acts as a global transcriptional regulator to control B . cenocepacia virulence by sensing BDSF. We show that BDSF binds to DsfR with high affinity and enhances the binding of DsfR to the promoter DNA regions of target genes. Furthermore, we demonstrate that the homolog of DsfR in B. lata , RS02960, binds to the target gene promoter, and perception of BDSF enhances the binding activity of RS02960. Together, these results provide insights into the evolved unusual functions of DsfR that control bacterial virulence as a response regulator of QS signal.
研究领域:
微生物学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）