Jilin Enrty Exit Inspection and Quarantine Bureau

Changchun, China

Jilin Enrty Exit Inspection and Quarantine Bureau

Changchun, China
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Wei J.,Changchun Normal University | Wei J.,Jilin University | Liang J.,Institute of Zoonosis | Shi Q.,Institute of Zoonosis | And 5 more authors.
Brazilian Journal of Microbiology | Year: 2014

Mycobacterium tuberculosis (M. tuberculosis), the causative agent of tuberculosis, still causes higher mortality than any other bacterial pathogen until now. With the emergence and spread of multidrug-resistant (MDR) and extensively drug-resistant (XDR-TB) strains, it becomes more important to search for alternative targets to develop new antimycobacterial drugs. Lupulone is a compound extracted from Hops (Hurnulus lupulus), which exhibits a good antimicrobial activity against M. tuberculosis with minimal inhibitory concentration (MIC) value of 10 μg/mL, but the response mechanisms of lupulone against M. tuberculosis are still poorly understood. In this study, we used a commercial oligonucleotide microarray to determine the overall transcriptional response of M. tuberculosis H37Rv triggered by exposure to MIC of lupulone. A total of 540 genes were found to be differentially regulated by lupulone. Of these, 254 genes were upregulated, and 286 genes were downregulated. A number of important genes were significantly regulated which are involved in various pathways, such as surface-exposed lipids, cytochrome P450 enzymes, PE/PPE multigene families, ABC transporters, and protein synthesis. Real-time quantitative RT-PCR was performed for choosed genes to verified the microarray results. To our knowledge, this genome-wide transcriptomics approach has produced the first insights into the response of M. tuberculosis to a lupulone challenge. © 2014, Sociedade Brasileira de Microbiologia.

Bi X.,Jilin University | Guo N.,Jilin University | Jin J.,Jilin University | Liu J.,Jilin University | And 15 more authors.
Journal of Applied Microbiology | Year: 2010

Aim: To determine the transcriptional responses of model fungus Saccharomyces cerevisiae (S. cerevisiae) cells upon exposure to thymol (THY). Methods and Results: Commercial oligonucleotide microarrays and quantitative real-time RT-PCR were used to study the transcriptional responses of S. cerevisiae to THY. Compared with the transcriptional profiles of untreated cultures, 305 genes were significantly upregulated, and 212 genes were significantly downregulated in THY-treated cells. We interpreted the microarray data using a hierarchical clustering tool, T-profiler. Glucose-dependent efflux of rhodamine 6G (R6G) from S. cerevisiae was performed to assay a phenotypic correlation between ATP-binding cassette transporter overexpression induced by THY and efflux of R6G. The addition of THY resulted in an increase in the concentration of released fluorescence, following the addition of glucose. Additional phenotype analysis showed that the intracellular concentration of thiamine was decreased by THY, and THY led to lesions in the membranes; these were consistent with the results of microarray. Conclusion: The transcriptional response of S. cerevisiae to THY was determined, and several changes in genetic regulation were verified in physiological effects on the cell. Significance and Impact of the Study: Taken a whole-genome view to elucidate the mechanism of THY as a potential antifungal agent. © 2009 The Society for Applied Microbiology.

Yu L.,Jilin University | Guo N.,Jilin University | Yang Y.,Jilin University | Wu X.,Jilin University | And 6 more authors.
Journal of Industrial Microbiology and Biotechnology | Year: 2010

p-Anisaldehyde (4-methoxybenzaldehyde), an extract from Pimpinella anisum L. seeds, is a potential novel preservative. To reveal the possible action mechanism of p-anisaldehyde against microorganisms, yeast-based commercial oligonucleotide microarrays were used to analyze the genome-wide transcriptional changes in response to p-anisaldehyde. Quantitative real-time RT-PCR was performed for selected genes to verify the microarray results. We interpreted our microarray data with the clustering tool, T-profiler. Analysis of microarray data revealed that p-anisaldehyde induced the expression of genes related to sulphur assimilation, aromatic aldehydes metabolism, and secondary metabolism, which demonstrated that the addition of p-anisaldehyde may influence the normal metabolism of aromatic aldehydes. This genome-wide transcriptomics approach revealed first insights into the response of Saccharomyces cerevisiae (S. cerevisiae) to p-anisaldehyde challenge. © 2009 Society for Industrial Microbiology.

Zhao X.,Jilin University | Liu Z.,Jilin University | Li W.,Jilin University | Li X.,Jilin Agricultural University | And 8 more authors.
Food Control | Year: 2014

Nisin has been widely used as a natural preservative in foods including dairy products, but the emergence of the nisin-resistant strains could compromise its use to control food-borne pathogens. It has been reported that coenzyme Q (CoQ) is a powerful antioxidant, but a small number of studies have described the antibacterial activity of CoQ. One of the most abundant forms of CoQ is CoQ10. CoQ0 is chosen for this study, which is the water-soluble homolog of CoQ10. In the present study, the invitro interaction of nisin and CoQ0 against 15 food-borne isolates of Staphylococcus aureus was assessed using a checkerboard microdilution method. Synergism was observed in strains tested, the FICI values ranging from 0.25 to 0.375. No antagonistic interaction between nisin and CoQ0 occurred. The positive interactions were verified confirmed using the time-killing test and agar diffusion assay. Our discovery of efficacy of combining nisin with CoQ0 might pave the way for a novel solution for spoilage problem in food industry and provide an alternative approach to overcome antimicrobial drug resistance. © 2014 Elsevier Ltd.

Meng R.,Jilin University | Zhao Z.,Jilin University | Guo N.,Jilin University | Liu Z.,Jilin University | And 10 more authors.
Journal of Medical Microbiology | Year: 2015

Listeria monocytogenes is considered one of the most important foodborne pathogens. The virulence-related proteins listeriolysin O (LLO) and p60 are critical factors involved in Listeria pathogenesis. In the present study, we investigated the effect of honokiol on LLO and p60 secreted from L. monocytogenes. A listeriolysin assay was used to investigate the haemolytic activities of L. monocytogenes exposed to honokiol, and the secretion of LLO and p60 was detected by immunoblot analysis. Additionally, the influence of honokiol on the transcription of LLO and p60 genes (hly and iap, respectively) was analysed by real-time reverse transcription PCR. TNF-α release assays were performed to elucidate the biological relevance of changes in LLO and p60 secretion induced by honokiol. According to the data, honokiol showed good anti-L. monocytogenes activity, with MICs of 8–16 µg ml-1, and the secretion of LLO and p60 was decreased by honokiol. In addition, the transcription of hly and iap was inhibited by honokiol. Our results indicate that TNF-α production by RAW264.7 cells stimulated with L. monocytogenes supernatants was inhibited by honokiol. Based on these data, we propose that honokiol could be used as a promising natural compound against L. monocytogenes and its virulence factors. © 2015 The Authors.

Shi C.,Jilin University | Zhao X.,Jilin University | Yan H.,Jilin University | Meng R.,Jilin Enrty exit Inspection and Quarantine Bureau | And 4 more authors.
Food Control | Year: 2016

Staphylococcus aureus ( S. aureus), a major food-borne pathogen, causes disease in mammalian hosts by producing a wide variety of exoproteins, such as α-hemolysin and staphylococcal enterotoxins. Tea tree oil (TTO), an essential oil, has broad-spectrum antimicrobial activity. The objectives of this study were to evaluate the inhibitory effects of TTO on S. aureus growth and on α-hemolysin, enterotoxins A and B production. In this study, the effect of TTO on S. aureus growth in laboratory medium and pasteurized milk was determined by time-kill assays. Treatment with half of minimal inhibitory concentration (MIC) of TTO demonstrated very little or no reduction in numbers of viable ATCC 29213 cells; however, 1 × MIC of TTO reduced the viable cell count more noticeably, and 2 × MIC of TTO demonstrated an even greater reduction in the viable cell count, both in TSB and milk. The influence of TTO on enterotoxins was determined by real-time reverse transcriptase-PCR (real-time RT-PCR), a hemolysis assay, Western blot and a tumor necrosis factor alpha (TNF-α) assay. The real-time RT-PCR results revealed that the transcription of genes encoding α-hemolysin, staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin B (SEB) were down regulated after S. aureus was exposed to TTO (0.0625 mg/mL-0.5 mg/mL). The hemolytic assay showed that S. aureus hemolytic activity was inhibited by subinhibitory concentrations of TTO (0.0625 mg/mL-0.5 mg/mL). The Western blot assay identified that the production of the three virulence factors was inhibited by TTO (0.0625 mg/mL-0.5 mg/mL). Moreover, the enzyme linked immunosorbent assay (ELISA) demonstrated that TNF-α production was suppressed by TTO treatment in RAW264.7 cells stimulated by S. aureus supernatant containing staphylococcal enterotoxins (SEs). © 2015 Elsevier Ltd.

Li W.-L.,Jilin University | Zhao X.-C.,Jilin University | Zhao Z.-W.,Jilin University | Huang Y.-J.,Jilin University | And 5 more authors.
Journal of Asian Natural Products Research | Year: 2016

Staphylococcus aureus (S. aureus) can attach to food, host tissues and the surfaces of medical implants and form a biofilm, which makes it difficult to eliminate. The purpose of this study was to evaluate the effect of honokiol on biofilm-grown S. aureus. In this report, honokiol showed effective antibacterial activity against S. aureus in biofilms. S. aureus isolates are capable of producing distinct types of biofilms mediated by polysaccharide intercellular adhesion (PIA) or extracellular DNA (eDNA). The biofilms’ susceptibility to honokiol was evaluated using confocal laser scanning microscopy (CLSM) analysis. The transcript levels of the biofilm-related genes, the expression of PIA, and the amount of eDNA of biofilm-grown S. aureus exposed to honokiol were also investigated. The results of this study show that honokiol can detach existing biofilms, kill bacteria in biofilms, and simultaneously inhibit the transcript levels of sarA, cidA and icaA, eDNA release, and the expression of PIA. © 2016 Informa UK Limited, trading as Taylor & Francis Group

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