Wang X.,Northwest University, China |
Yan Q.,Sichuan Agricultural University |
Xia X.,Northwest University, China |
Zhang Y.,Northwest University, China |
And 4 more authors.
Applied and Environmental Microbiology | Year: 2013
Although Escherichia coli typically colonizes the intestinal tract and vagina of giant pandas, it has caused enteric and systemic disease in giant pandas and greatly impacts the health and survival of this endangered species. In order to understand the distribution and characteristics of E. coli from giant pandas, 67 fecal and 30 vaginal E. coli isolates from 21 giant pandas were characterized for O serogroups, phylogenetic groups, antimicrobial susceptibilities, and pulsed-field gel electrophoresis (PFGE) profiles. In addition, these isolates were tested for the presence of extraintestinal pathogenic E. coli (ExPEC) and diarrheagenic E. coli (DEC) by multiplex PCR detection of specific virulence genes. The most prevalent serogroups for all E. coli isolates were O88, O18, O167, O4, and O158. ExPEC isolates were detected mostly in vaginal samples, and DEC isolates were detected only in fecal samples. Phylogenetic group B1 predominated in fecal isolates, while groups B2 and D were frequently detected in vaginal isolates. Resistance to trimethoprim-sulfamethoxazole was most frequently observed, followed by resistance to nalidixic acid and tetracycline. All except five isolates were typeable by using XbaI and were categorized into 74 PFGE patterns. Our findings indicate that panda E. coli isolates exhibited antimicrobial resistance, and potentially pathogenic E. coli isolates were present in giant pandas. In addition, these E. coli isolates were genetically diverse. This study may provide helpful information for developing strategies in the future to control E. coli infections of giant pandas. © 2013, American Society for Microbiology.
Wang T.,Sichuan Agricultural University |
Chen Z.,Sichuan Agricultural University |
Yu H.,Sichuan Entry Exit Inspection and Quarantine Bureau |
Xie Y.,Sichuan Agricultural University |
And 4 more authors.
Parasitology Research | Year: 2015
Cryptosporidium is a global epidemic parasite and one of the most important intestinal pathogens causing diarrhea in animals and humans. Despite extensive research on this parasite group, little is known about rates of Cryptosporidium infection in lesser pandas. In this study, we use molecular diagnostic tools to detect Cryptosporidium infections and identify Cryptosporidium species in the lesser panda. Using a PCR approach, we sequenced the 18S rRNA gene in fecal samples collected from 110 captive lesser pandas held throughout China (approximately one third of the captive population). We determined Cryptosporidium species via a BLAST comparison of our sequences against those of published Cryptosporidium sequences available in GenBank and subsequent phylogenetic analysis. We report that captive lesser pandas were infected with a single Cryptosporidium species, Cryptosporidium andersoni, at a prevalence of 6.36 % (7/110). The present investigation revealed the existence of C. andersoni infection in captive lesser panda and suggested that proper control measures should be taken carefully to protect the welfare of zoo workers and visitors. © 2015, Springer-Verlag Berlin Heidelberg.
Li Y.,University of Sichuan |
Zhang H.,Centers for Disease Control and Prevention |
Hu J.,Sichuan Entry Exit Inspection and Quarantine Bureau |
Xue F.,University of Sichuan |
Sun C.,University of Sichuan
Journal of Chromatographic Science | Year: 2012
A gas chromatography-electron impact-tandem mass spectrometric method was established for the simultaneous determination of seven adulterants, including fenfluramine (FEN), norpseudoephedrine (NPE), pseudoephedrine (PSE), ephedrine (EPH), amfepramone (AMF), sibutramine (SIB) and strychnine (STR) in slimming functional foods. The target chemicals were extracted with 2 formic acid solution and then cleaned-up with solid-phase extraction using a strong cation exchange cartridge from tablet, liquid, mixed plant powder and capsule formulations. Chromatographic separation was accomplished on a VF-5MS column within 23 min. Leucomalachite green was employed as an internal standard. The recoveries of seven target chemicals in two formulations ranged from 80.1 to 106. Limits of detection of the method were from 7.5 to 375 g/kg with relative standard deviations of 1.6 to 13.9. The linearity of the method ranged from 90 to 1500 ng/mL for NPE, 150 to 1500 ng/mL for STR, 10 to 500 ng/mL for AMF, 5.0 to 500 ng/mL for PSE and EPH and 3.0 to 500 ng/mL for FEN and SIB. This method was applied to the determination of six brands of slimming functional foods. SIB was detected in five of the samples with the contents in the range of 10.3 - 8.55 × 105 μg/kg. © 2012 The Author . Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissionsoup.com.
Liu Y.,Sichuan University |
Yang Y.,Sichuan Entry exit Inspection and Quarantine Bureau |
Zhao F.,Sichuan Entry exit Inspection and Quarantine Bureau |
Fan X.,Sichuan Entry exit Inspection and Quarantine Bureau |
And 3 more authors.
Southeast Asian Journal of Tropical Medicine and Public Health | Year: 2013
We collected flies from Chengdu Shuangliu International Airport to examine for the presence of bacteria and to determine the sensitivity patterns of those bacteria. A total of 1,228 flies were collected from 6 sites around Chengdu Shuangliu International Airport from April to September 2011. The predominant species was Chrysomya megacephala (n=276, 22.5%). Antimicrobial-resistant gram-negative enteric bacteria (n=48) were isolated from flies using MacConkey agar supplemented with cephalothin (20 μg/ml). These were identified as Escherichia coli (n=37), Klebsiella pneumoniae (n=6), Pseudomonas aeruginosa (n=3) and Aeromonas hydrophila (n=2). All isolated bacteria were tested for resistance to 21 commonly used antimicrobials: amoxicillin (100%), ticarcillin (100%), cephalothin (100%), cefuroxime (100%), ceftazidime 1 (93.8%), piperacillin (93.8%), cefotaxime (89.6%), ticarcillin-clavulanate (81.3%), trimethoprim-sulfamethoxazole (62.5%), ciprofloxacin (54.2%), gentamicin (45.8%), cefepime (39.6%), tobramycin (39.6%), ceftazidime (22.9%), cefoxitin (16.7%), amikacin (16.7%), netilmicin (14.6%), amoxicillin-clavulanate (6.3%) and piperacillin-tazobactam (2.1%). No resistance to meropenem or imipenem was observed. Antibiotic resistance genes among the isolated bacteria were analyzed for by polymerase chain reaction. Thirty of the 48 bacteria with resistance (62.5%) possessed the blaTEM gene.
Gu A.,Sichuan University |
Li Z.,Sichuan Entry Exit Inspection and Quarantine Bureau |
Liu S.,Sichuan University |
Gong T.,Sichuan University |
Yu Z.,Sichuan University
Journal of Polymer Research | Year: 2013
Poly(phenylene sulfide ether) (PPSE) with increased molecular weight was synthesized by means of the quantitative conversion of a poly(phenylene sulfoxide ether sulfide ether) (PPSOESE) precursor via a modified reduction method. PPSOESE precursor was prepared in good yield using polycondensation reaction between bis(4-fluorophenyl) sulfoxide (BFPSO) and bis(4-hydroxyphenyl) sulfide (BHPS). The effects of reaction conditions on the synthesis of PPSOESE and its conversion to PPSE were examined and the conditions were optimized. The results showed that the solvent, reaction temperature, and total monomer concentration are important factors affecting the yield and molecular weight of PPSOESE. For the reduction of PPSOESE to PPSE, the solvents and the feeding rate of the reducing reagent are key factors controlling the quantitative conversion of sulfoxide to sulfide. Structural characterization displayed that PPSOESE is amorphous and has the desired linear structure, and the derived PPSE is semicrystalline with low crystallinity. The study indicated that alternative introduction of ether units induces a gauche conformation relative to that of poly(phenylene sulfide) (PPS), resulting in crystallinity depression. PPSE with a number-average molecular weight of 1.7 × 104 g mol-1 was obtained in 92.4 % yield, which was much higher than that previously reported for PPSE. Thermal analyses showed that the glass transition temperature (Tg) and the melting temperature (Tm) of the obtained PPSE are 92 °C and 192 °C, respectively. Thermogravimetric analysis indicated that PPSE has high thermal stability with a degradation onset temperature above 470 °C. © 2013 Springer Science+Business Media Dordrecht.
Zhenwei W.,University of Electronic Science and Technology of China |
Feng C.,University of Electronic Science and Technology of China |
Ping L.,Sichuan Entry Exit Inspection and Quarantine Bureau |
Yujie L.,Sichuan Entry Exit Inspection and Quarantine Bureau
International Journal of Damage Mechanics | Year: 2013
Fatigue failure occurs for many metal materials, and it affects the product reliability. Therefore, the fatigue life predication is important for metal materials under conditions of heavy and high-speed loading. Presently, many researches have focused on the fatigue life predication and many fatigue life predication methods have been used industrially, such as Manson-Coffin relation and damage strain model. However, few reports can be found on the predication accuracy. Based on Manson-Coffin relation and damage strain model, this paper analyzes the effect of the material performance εf on the predication accuracy. Furthermore, it is pointed out that single material performance will cause the low calculation accuracy. Then, an improved formula is derived to predicate the strain fatigue life. This formula is related to two material performances εf and Δεc. Moreover, the predication accuracy analysis is conducted through calculating error. Finally, experiments prove that this formula can greatly improve the calculation accuracy. Therefore, this proposed formula is reliable and reasonable. © The 2012 Author(s).
Niu J.-Z.,Southwest University |
Liu G.-Y.,Sichuan Entry Exit Inspection and Quarantine Bureau |
Dou W.,Southwest University |
Wang J.-J.,Southwest University
Florida Entomologist | Year: 2011
Nine field collected populations of Panonychus citri from Chinese citrus orchards were assayed for susceptibility to pyridaben and the alternative acaricide azocyclotin and activity of glutathione S-transferases (GSTs). The results showed that populations from Pujiang, Wanzhou, and Pengshan exhibited a low level of sensitivity to pyridaben, but demonstrated a high level of sensitivity to azocyclotin. The correlation coefficient between GSTs activities and the LC 50 of pyridaben was r = 0.93 while the correlation coefficient between GSTs activities and the LC 50 of azocyclotin was r = 0.03. The V max value of CDNB (1-chloro-2, 4-dinitrobenzene) in populations from Beibei, Jintang, Pengshan, Wanzhou, and Zhongxian exhibited a: 2.5-, 11.6-, 7.0-, 5.1-, and 6.4-fold increase in resistance, respectively, relative to the pyridaben susceptible population. In addition, azocyclotin was the most sensitive inhibitor of the GSTs compared with the EA (ethacrynic acid) and pyridaben, based on the values for I 50. The current study suggested that GSTs might be involved in resistance of P. citri to pyridaben and but not azocyclotin in the field.
Li J.,Chengdu University of Technology |
Li L.,Chengdu University of Technology |
Tong J.,Chengdu University of Technology |
Wang Y.,Chengdu University of Technology |
Chen S.,Sichuan Entry Exit Inspection and Quarantine Bureau
Energy Procedia | Year: 2011
Lipases are important catalysts in the production of biodiesel and they are widely available in natural world, including aminal, plant, microorganism.The cost of biodiesel production is the resources cost, which is the key determinant of biodiesel prices and the bottleneck factor restricting profit of biodiesel producers.This article addresses the sources of lipases, renewable sources of biodiesel, and the production of biodiesel with lipases. © 2011 Published by Elsevier B.V. Selection and/or peer-review under responsibility of International Materials Science Society.
PubMed | Leshan Normal University, Guangdong Academy of Agricultural Sciences and Sichuan Entry exit Inspection and Quarantine Bureau
Type: | Journal: Journal of insect science (Online) | Year: 2015
The bamboo aphid, Pseudoregma bambucicola, is an important insect pest of bamboo that affects normal bamboo growth and induces sooty molds. The control of P. bambucicola involves the application of chemicals, such as imidacloprid, to which many species are resistant. In this study, we isolate a novel botanical pesticide (9-oxo-10,11-dehydro-ageraphorone) from an Eupatorium adenophorum(Asteraceae: Compositae) petroleum ether extract and test the aphicidal activity of this compound against P. bambucicola in laboratory bioassay and field-based experiments. This ageraphorone compound at a concentration of 2mg/ml caused 73.33% mortality (corrected mortality [Subtracted the mortality of the negative control]: 70%) of P. bambucicola by laboratory bioassay within 6h. Even at lower concentrations, this compound caused greater 33% mortality (corrected mortality: 30%) of aphids. Field experiments with naturally infested bamboo plants showed that two applications of 2mg/ml ageraphorone to infested plants completely cleared infestations within 30d. These effects were similar to those of the positive control (imidacloprid). These results reveal that 9-oxo-10,11-dehydro-ageraphorone exhibits significant aphicidal activity against bamboo aphids. We suggest that future research be directed at developing this ageraphorone compound from E. adenophorum as an aphicidal agent for biocontrol.
Li Y.,University of Sichuan |
Hu J.,Sichuan Entry Exit Inspection and Quarantine Bureau |
Shi Y.,University of Sichuan |
Sun A.,University of Sichuan |
Sun C.,University of Sichuan
Food Analytical Methods | Year: 2011
A high-performance liquid chromatography-electrospray ionization-tandem mass spectrometric method for simultaneous determination of seven adulterants including pseudoephedrine, norpseudoephedrine, caffeine, strychnine, fenfluramine, sildenafil, and amfepramone in slimming functional foods was established. For tablet formulation, the target chemicals were extracted with ammoniated methanol, while for liquid samples, plant powder, or capsules formulations, these chemicals were extracted with a mixture solution of ammoniated methanol-diethyl ether (2:1 v/v). After anhydrous sodium sulfate being added, the extracts were centrifuged and then the supernatant was evaporated to dryness under condition of a nitrogen gas flow. The residue was reconstituted with acetonitrile-water (1:9 v/v) to produce a test solution. Chromatographic separation was accomplished using a RP-C18 column with a gradient elution procedure using 0.03% formic acid in acetonitrile and 0.01% formic acid solution. Seven chemicals were separated and detected in 10 min. Clenbuterol was used as an internal standard. The recoveries of seven targeted chemicals in different formulations are from 81.2% to 110.3%. Limits of detection of the method are from 4.2 to 16.7 μg kg -1 with relative standard deviations of 1.1-8.4%. The linearity of the method ranges from 2.0 to 500 ng mL -1 for all chemicals, with linear correlation coefficients varying from 0.9982 to 0.9992. The method has been used for determining the target chemicals in nine slimming functional foods, and satisfactory results are achieved. Among these tested samples, norpseudoephedrine and fenfluramine were not detected for all samples. Some other components, such as pseudoephedrine, amfepramone, strychnine, and sildenafil were detected in one or more samples, while caffeine was detected in almost all of these tested samples. © 2011 Springer Science+Business Media, LLC.