An extensively drug-resistant(XDR)Escherichia coli strain 258E was isolated from an anal swab sample of a chicken farm of Anhui province in China.Genomic analyses indicated that the strain 258E harbors an incompatibil...An extensively drug-resistant(XDR)Escherichia coli strain 258E was isolated from an anal swab sample of a chicken farm of Anhui province in China.Genomic analyses indicated that the strain 258E harbors an incompatibility group N(IncN)plasmid pEC258-3,which co-produces bla_(CTX-M-3),bla_(KPC-2),bla_(TEM-1B),qnrS1,aac(6')-Ib-cr,dfrA14,arr-3,and aac(6')-Ib3.Multiple genome arrangement analyses indicated that pEC258-3 is highly homologous with pCRKP-1-KPC discovered in Klebsiella pneumoniae from a patient.Furthermore,conjugation experiments proved that plasmid pEC258-3 can be transferred horizontally and may pose a significant potential threat in animals,community and hospital settings.展开更多
3-hydroxydecanoic acid (3HD) is an interesting intermediate for chemical synthesis of many valuable compounds. A novel method to produce 3HD by recombinant bacteria was constructed in Escherichia coli HB101 and Pseudo...3-hydroxydecanoic acid (3HD) is an interesting intermediate for chemical synthesis of many valuable compounds. A novel method to produce 3HD by recombinant bacteria was constructed in Escherichia coli HB101 and Pseudomonas putida GPpl04, respectively. Simultaneous expression of both phaG encoding (R)-3-hydroxydecanoyl-ACP:CoA transacylase and tesB encoding thioesteraseⅡin E. coli HB101 increased 3HD production approximate 1.7-folds compared with the expression of phaG gene alone under identical conditions. In addition, when the tesB gene was introduced into the strain, the polyhydroxyalkanoate synthase negative strain P. putida GPpl04 produced extracellular 3HD. Thus, a novel pathway to produce 3HD by recombinant Pseudomonas was constructed. It was also found that the ratio of carbon source to nitrogen source affected the production of 3HD by recombinant P. putida harboring tesB gene. Nitrogen limitation seemed to promote the extracellular 3HD production.展开更多
Infections with multidrug-resistant(MDR)Gram-negative bacteria,such as MDR Escherichia coli(E.coli),remain a challenge due to the lack of safe antibiotics and high fatality rates under anti-infection therapies.This wo...Infections with multidrug-resistant(MDR)Gram-negative bacteria,such as MDR Escherichia coli(E.coli),remain a challenge due to the lack of safe antibiotics and high fatality rates under anti-infection therapies.This work presents a form of biomimetic intelligent catalysis inspired by the selective biocatalytic property of macrophages(MΦs),consisting of an intelligent controlling center(a living MΦ)and a Fenton reaction catalyst(Fe_(3)O_(4)@poly(lactic-co-glycolic acid)(PLGA)nanoparticles)for killing MDR E.coli without harming normal cells.The MΦ-Fe_(3)O_(4)@PLGA particles(i.e.,the intelligent catalysis particles)exhibit selective biocatalysis activity toward MDR E.coli by producing H_(2)O_(2) and lipid droplets(LDs).This process activates the lipid metabolism and glycan biosynthesis and metabolism pathways based on the result of RNA sequencing data analysis.The H_(2)O_(2) further reacts with Fe_(3)O_(4)@PLGA to form highly toxic hydroxyl radicals(·OH),while the LDs contain antimicrobial peptides and can target MDR E.coli.The highly toxicOH and antimicrobial peptides are shown to combat with MDR E.coli,such that the antibacterial efficiency of the MΦ-Fe_(3)O_(4)@PLGA particles against MDR E.coli is 99.29%±0.31%in vitro.More importantly,after several passages,the intelligent catalysis function of the MΦ-Fe_(3)O_(4)@PLGA particles is well maintained.Hence,the concept of biomimetic intelligent catalysts displays potential for treating diseases other than infections.展开更多
A multivalent inactivated Escherichia coli vaccine for forest musk deer by using serotypes O4,O26,and O139 with Al（OH）3 adjuvant was prepared.The vaccine did not cause any adverse reactions in forest musk deer.The i...A multivalent inactivated Escherichia coli vaccine for forest musk deer by using serotypes O4,O26,and O139 with Al（OH）3 adjuvant was prepared.The vaccine did not cause any adverse reactions in forest musk deer.The immunogenic effects of the vaccine were experimentally investigated in pregnant and young forest musk deer.The serum antibody titers of pregnant and young forest musk deer were determined by performing the micro-agglutination test.The serum antibody titers of pregnant forest musk deer were more stable from 35th to 68th d after the third vaccination,and the serum antibody titers of four pregnant forest musk deer were maintained 25,25,25,and 24 on 68th d after the third vaccination.Young forest musk deer showed serum antibody titers which were obtained due to nursing.Young forest musk deer were administered the first intramuscular vaccine injection at an age of approximately 60 days due to a fall in maternal antibody titers.The serum antibody titers of young forest musk deer were higher after the third vaccination and maintained at approximately the same level until they were 137 days old.The maternal antibodies and the antibodies produced by young forest musk deer could be helpful for protecting the young musk deer from the infections of pathogenic Escherichia coli strains（serotypes O4,O26,and O139）for 137 days after birth（during the nursing period and the period when the forest musk deer were susceptible to diseases）.展开更多
AIM To obtain greater antigenicity of HCV NS3 protein. METHODS The HCV NS3 cDNA fragment was amplified by reverse transcription polymerase chain reaction from the sera of the HCV infected patients. The DNA sequence...AIM To obtain greater antigenicity of HCV NS3 protein. METHODS The HCV NS3 cDNA fragment was amplified by reverse transcription polymerase chain reaction from the sera of the HCV infected patients. The DNA sequence was determined by dideoxy mediated chain termination method using T7 polymerase. HCV NS3 protein was expressed in E. coli . RESULTS Sequence analysis indicated that the HCV isolate of this study belongs to HCV Ⅱ; SDS PAGE demonstrated an M r 23800 and an M r 22000 recombinant protein band which amount to 14% and 11% of the total bacterial proteins separately. Western blotting and ELISA showed NS3 protein possessed greater antigenicity. CONCLUSION Recombinant HCV NS3 protein was expressed successfully, which provided the basis for developing HCV diagnostic reagents.展开更多
Obiective:To investigate whether"Fuzheng Qingretonglin"decoction can reduce urinary tract damage caused by complex urinary tract infection caused by drug resistant Escherichia coli by regulating Nod-like rec...Obiective:To investigate whether"Fuzheng Qingretonglin"decoction can reduce urinary tract damage caused by complex urinary tract infection caused by drug resistant Escherichia coli by regulating Nod-like receptor pyrin domain3 inflammasome,and to explore the feasibility of this decoction combined with levofloxacin in the treatment of complex urinary tract infection caused by drug resistant bacteria.Methods:SD rats were divided into five groups:sham group,model group,levofloxacin group(Lev group),levofloxacin+Fuzheng Qingre Tonglin decoction group(FZ+lev group),and Fuzheng Qingre Tonglin decoction group(FZQRTL group).After the experiment,urine was taken for bacterial culture to determine the urinary tract infection of rats in each group;HE staining was used to observe the pathological changes of kidney and bladder tissues in rats;The expression of NLRP3 in kidney and bladder tissues was detected by immunohistochemistry;The expression of IL-1βand IL-18 in serum of rats was detected by ELISA;The expressions of NLRP3,ASC and Caspase-1 were detected by Western blotting.Results:The positive rate of urine bacteria culture in the sham group was 0%,the positive rate of urine bacteria culture in the model group was 100%;and the positive rate of urine bacteria culture in the FZ+lev group was 37.50%,which was statistically different from that in the model group(P<0.05).A large number of inflammatory cells were observed in the kidney and bladder tissues of the model group by HE staining,while the number of inflammatory cells in the kidney and bladder tissues of the Lev group and FZQRTL group was significantly reduced compared with that of the model group.The FZ+lev group in the number and structure of inflammatory cells in kidney and bladder were similar to the sham group.The NLRP3 immunohistochemistry of kidney and bladder tissue in FZ+lev groups and FZQRTL groups was significantly different from that in model group(P<0.001).The levels of IL-1βand IL-18 in serum of Lev group,FZQRTL group and FZ+lev group were significantly decreased by ELISA compared with model group(P<0.001).The levels of IL-1βand IL-18 in the FZ+lev groups were significantly lower than in the Lev group and FZQRTL group,and the differences were statistically significant(P<0.05).The protein expressions of NLRP3,ASC and Caspase-1 in the Lev group,FZQRTL group and FZ+lev group were significantly lower than those in the model group(P<0.001).The protein expressions of NLRP3,ASC and Caspase-1 in the FZ+lev groups were significantly lower than in the Lev group and FZQRTL group,and the differences were statistically significant(P<0.05).Conclusions:"Fuzheng Qingretonglin"decoction may have a protective effect on the kidney and bladder of rats with complex urinary tract infection caused by drug-resistant Escherichia coli by inhibiting the activation of NLRP3 inflammatory bodies,and TCM combined with levofloxacin has a better therapeutic effect than TCM or levofloxacin alone.展开更多
基金the National Key Research and Development Program of China(2018YFE0192600)the Shanghai Agriculture Applied Technology Development Program,China(T20200104)+1 种基金the Fundamental Research Funds for the Central Universities,China(2020JB05)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-ZDRW202203).
文摘An extensively drug-resistant(XDR)Escherichia coli strain 258E was isolated from an anal swab sample of a chicken farm of Anhui province in China.Genomic analyses indicated that the strain 258E harbors an incompatibility group N(IncN)plasmid pEC258-3,which co-produces bla_(CTX-M-3),bla_(KPC-2),bla_(TEM-1B),qnrS1,aac(6')-Ib-cr,dfrA14,arr-3,and aac(6')-Ib3.Multiple genome arrangement analyses indicated that pEC258-3 is highly homologous with pCRKP-1-KPC discovered in Klebsiella pneumoniae from a patient.Furthermore,conjugation experiments proved that plasmid pEC258-3 can be transferred horizontally and may pose a significant potential threat in animals,community and hospital settings.
基金Supported by the State Outstanding Young Scientist Award from National Natural Sciences Foundation of China (No. 20334020).
文摘3-hydroxydecanoic acid (3HD) is an interesting intermediate for chemical synthesis of many valuable compounds. A novel method to produce 3HD by recombinant bacteria was constructed in Escherichia coli HB101 and Pseudomonas putida GPpl04, respectively. Simultaneous expression of both phaG encoding (R)-3-hydroxydecanoyl-ACP:CoA transacylase and tesB encoding thioesteraseⅡin E. coli HB101 increased 3HD production approximate 1.7-folds compared with the expression of phaG gene alone under identical conditions. In addition, when the tesB gene was introduced into the strain, the polyhydroxyalkanoate synthase negative strain P. putida GPpl04 produced extracellular 3HD. Thus, a novel pathway to produce 3HD by recombinant Pseudomonas was constructed. It was also found that the ratio of carbon source to nitrogen source affected the production of 3HD by recombinant P. putida harboring tesB gene. Nitrogen limitation seemed to promote the extracellular 3HD production.
基金supported by the China National Funds for Distinguished Young Scientists (51925104)the National Natural Science Foundation of China (NSFC) (51871162 and 52173251)+1 种基金NSFC-Guangdong Province Joint Program (U21A2084)the Central Guidance on Local Science and Technology Development Fund of Hebei Province (226Z1303G).
文摘Infections with multidrug-resistant(MDR)Gram-negative bacteria,such as MDR Escherichia coli(E.coli),remain a challenge due to the lack of safe antibiotics and high fatality rates under anti-infection therapies.This work presents a form of biomimetic intelligent catalysis inspired by the selective biocatalytic property of macrophages(MΦs),consisting of an intelligent controlling center(a living MΦ)and a Fenton reaction catalyst(Fe_(3)O_(4)@poly(lactic-co-glycolic acid)(PLGA)nanoparticles)for killing MDR E.coli without harming normal cells.The MΦ-Fe_(3)O_(4)@PLGA particles(i.e.,the intelligent catalysis particles)exhibit selective biocatalysis activity toward MDR E.coli by producing H_(2)O_(2) and lipid droplets(LDs).This process activates the lipid metabolism and glycan biosynthesis and metabolism pathways based on the result of RNA sequencing data analysis.The H_(2)O_(2) further reacts with Fe_(3)O_(4)@PLGA to form highly toxic hydroxyl radicals(·OH),while the LDs contain antimicrobial peptides and can target MDR E.coli.The highly toxicOH and antimicrobial peptides are shown to combat with MDR E.coli,such that the antibacterial efficiency of the MΦ-Fe_(3)O_(4)@PLGA particles against MDR E.coli is 99.29%±0.31%in vitro.More importantly,after several passages,the intelligent catalysis function of the MΦ-Fe_(3)O_(4)@PLGA particles is well maintained.Hence,the concept of biomimetic intelligent catalysts displays potential for treating diseases other than infections.
基金Supported by Youth Foundation of Education Department in Sichuan Province(07ZB060)Scientific and Technological Supporting Project in Science and Technology Bureau of Sichuan Province(2009SZ0228)~~
文摘A multivalent inactivated Escherichia coli vaccine for forest musk deer by using serotypes O4,O26,and O139 with Al（OH）3 adjuvant was prepared.The vaccine did not cause any adverse reactions in forest musk deer.The immunogenic effects of the vaccine were experimentally investigated in pregnant and young forest musk deer.The serum antibody titers of pregnant and young forest musk deer were determined by performing the micro-agglutination test.The serum antibody titers of pregnant forest musk deer were more stable from 35th to 68th d after the third vaccination,and the serum antibody titers of four pregnant forest musk deer were maintained 25,25,25,and 24 on 68th d after the third vaccination.Young forest musk deer showed serum antibody titers which were obtained due to nursing.Young forest musk deer were administered the first intramuscular vaccine injection at an age of approximately 60 days due to a fall in maternal antibody titers.The serum antibody titers of young forest musk deer were higher after the third vaccination and maintained at approximately the same level until they were 137 days old.The maternal antibodies and the antibodies produced by young forest musk deer could be helpful for protecting the young musk deer from the infections of pathogenic Escherichia coli strains（serotypes O4,O26,and O139）for 137 days after birth（during the nursing period and the period when the forest musk deer were susceptible to diseases）.
文摘AIM To obtain greater antigenicity of HCV NS3 protein. METHODS The HCV NS3 cDNA fragment was amplified by reverse transcription polymerase chain reaction from the sera of the HCV infected patients. The DNA sequence was determined by dideoxy mediated chain termination method using T7 polymerase. HCV NS3 protein was expressed in E. coli . RESULTS Sequence analysis indicated that the HCV isolate of this study belongs to HCV Ⅱ; SDS PAGE demonstrated an M r 23800 and an M r 22000 recombinant protein band which amount to 14% and 11% of the total bacterial proteins separately. Western blotting and ELISA showed NS3 protein possessed greater antigenicity. CONCLUSION Recombinant HCV NS3 protein was expressed successfully, which provided the basis for developing HCV diagnostic reagents.
基金Luzhou People's Government-Science and technology Strategic Cooperation project of Southwest Medical University(2017LZXNYD-T09)。
文摘Obiective:To investigate whether"Fuzheng Qingretonglin"decoction can reduce urinary tract damage caused by complex urinary tract infection caused by drug resistant Escherichia coli by regulating Nod-like receptor pyrin domain3 inflammasome,and to explore the feasibility of this decoction combined with levofloxacin in the treatment of complex urinary tract infection caused by drug resistant bacteria.Methods:SD rats were divided into five groups:sham group,model group,levofloxacin group(Lev group),levofloxacin+Fuzheng Qingre Tonglin decoction group(FZ+lev group),and Fuzheng Qingre Tonglin decoction group(FZQRTL group).After the experiment,urine was taken for bacterial culture to determine the urinary tract infection of rats in each group;HE staining was used to observe the pathological changes of kidney and bladder tissues in rats;The expression of NLRP3 in kidney and bladder tissues was detected by immunohistochemistry;The expression of IL-1βand IL-18 in serum of rats was detected by ELISA;The expressions of NLRP3,ASC and Caspase-1 were detected by Western blotting.Results:The positive rate of urine bacteria culture in the sham group was 0%,the positive rate of urine bacteria culture in the model group was 100%;and the positive rate of urine bacteria culture in the FZ+lev group was 37.50%,which was statistically different from that in the model group(P<0.05).A large number of inflammatory cells were observed in the kidney and bladder tissues of the model group by HE staining,while the number of inflammatory cells in the kidney and bladder tissues of the Lev group and FZQRTL group was significantly reduced compared with that of the model group.The FZ+lev group in the number and structure of inflammatory cells in kidney and bladder were similar to the sham group.The NLRP3 immunohistochemistry of kidney and bladder tissue in FZ+lev groups and FZQRTL groups was significantly different from that in model group(P<0.001).The levels of IL-1βand IL-18 in serum of Lev group,FZQRTL group and FZ+lev group were significantly decreased by ELISA compared with model group(P<0.001).The levels of IL-1βand IL-18 in the FZ+lev groups were significantly lower than in the Lev group and FZQRTL group,and the differences were statistically significant(P<0.05).The protein expressions of NLRP3,ASC and Caspase-1 in the Lev group,FZQRTL group and FZ+lev group were significantly lower than those in the model group(P<0.001).The protein expressions of NLRP3,ASC and Caspase-1 in the FZ+lev groups were significantly lower than in the Lev group and FZQRTL group,and the differences were statistically significant(P<0.05).Conclusions:"Fuzheng Qingretonglin"decoction may have a protective effect on the kidney and bladder of rats with complex urinary tract infection caused by drug-resistant Escherichia coli by inhibiting the activation of NLRP3 inflammatory bodies,and TCM combined with levofloxacin has a better therapeutic effect than TCM or levofloxacin alone.
