BACKGROUND:The virulent factors of Escherichia coli(E.coli) play an important role in the process of pathopoiesis.The study aimed to compare drug-resistant genes and virulence genes between extended spectrum β-lactam...BACKGROUND:The virulent factors of Escherichia coli(E.coli) play an important role in the process of pathopoiesis.The study aimed to compare drug-resistant genes and virulence genes between extended spectrum β-lactamases(ESBLs)-producing E.coli and non-ESBLs-producing E.coli to provide a reference for physicians in management of hospital infection.METHODS:From October 2010 to August 2011,96 drug-resistant strains of E.coli isolated were collected from the specimens in Qingdao Municipal Hospital,Qingdao,China.These bacteria strains were divided into a ESBLs-producing group and a non-ESBLs-producing group.Drug sensitivity tests were performed using the Kirby-Bauer(K-B) method.Disinfectant gene,qacEA1-sull and 8 virulence genes(CNF2,hlyA,eaeA,VT1,est,bfpA,elt,and CNF1) were tested by polymerase chain reaction(PCR).RESULTS:Among the 96 E.coli isolates,the ESBLs-producing E.coli comprised 46(47.9%)strains and the non-ESBLs-producing E.coli consisted of 50(52.1%) strains.The detection rates of multiple drug-resistant strain,qacEA1-sull,CNF2,hlyA,eaeA,VT1,est,bfpA,elt,and CNF1 in 46ESBLs-producing E.coli isolates were 89.1%,76.1%,6.5%,69.6%,69.6%,89.1%,10.9%,26.1%,8.7%,and 19.6%,respectively.In the non-ESBLs-producing E.coli strains,the positive rates of multiple drug-resistant strain,qacEA1-sull,CNF2,hlyA,eaeA,VT1,est,bfpA,elt,and CNF1 were 62.0%,80.0%,16.0%,28.0%,64.0%,38.0%,6.0%,34.0%,10.0%,and 24.0%,respectively.The difference in the detection rates of multiple drug-resistant strain,hlyA and VT1 between the ESBLs-producing E.coli strains and the non-ESBLs-producing E.coli strains was statistically significant(P<0.05).CONCLUSION:The positive rate of multiple drug-resistant strains is higher in the ESBLsproducing strains than in the non-ESBLs-producing strains.The expression of some virulence genes hlyA and VT1 varies between the ESBLs-producing strains and the non-ESBLs-producing strains.Increased awareness of clinicians and enhanced testing by laboratories are required to reduce treatment failures and prevent the spread of multiple drug-resistant strains.展开更多
The UV irradiation is used for removing Antibiotic Resistant Bacteria(ARB)and Antibiotic Resistance Genes(ARG)from wastewater treatment.Bacteriophages are viruses that infect within bacteria,are recognized for bacteri...The UV irradiation is used for removing Antibiotic Resistant Bacteria(ARB)and Antibiotic Resistance Genes(ARG)from wastewater treatment.Bacteriophages are viruses that infect within bacteria,are recognized for bacterial control.The influence of some parameters in quantification and performance influencing of pathogen demobilization could be considered in disinfection of wastewater.The comparison of Polyvalent phage(NE1)versus Coliphage(NE4)in suppressing a bacterium Escherichia coli(NDM-1:b-lactam-resistant)with UV irradiation was observed the efficacy in reduction of cells in the disinfection and parameter process.The results with the effect of UV-C irradiation on NDM-1 infected with 1%of NE4 showed a decrease of cells from 8×10^(6)to 2×10^(5)in 60 min with UV-C dose.The NDM1(E.coli)was infected with 1%of NE4(Polyvalent Phage)under magnetic stirring for 1 h,the cells count was 8×10^(6).After 1 h in UV-C e×posure,the cells number reached 3×10^(5).The NDM1 that was e×posed in 1 h of UV-C irradiation and then was infected with 1%of NE4.Cells counting were done 24 h after this procedure.These cells were e×posed in UV-C and showed a reduction in the number of cells from 1×10^(8)to 4×10^(5)after 60 min.The results indicate that bacteriophages can mitigate bacteria species,and combined the conventional water disinfection technologies that can support the microbial safety control strategies.展开更多
Varicella-zoster virus(VZV)is a highly infectious agent responsible for both varicella and herpes zoster disease.Despite high efficacy,there remain safety and accessibility concerns with the licensed vaccines.Here,we ...Varicella-zoster virus(VZV)is a highly infectious agent responsible for both varicella and herpes zoster disease.Despite high efficacy,there remain safety and accessibility concerns with the licensed vaccines.Here,we sought to produce a VZV g E immunogen using an E.coli expression system.We found that the soluble expression and yield of g E protein could be enhanced via C-terminal truncations to the protein,thereby facilitating a robust and scalable purification process for the purpose of vaccine manufacturing.The lead truncated g E(aa 31–358),hereafter referred to as tg E,was a homogenous monomer in solution and showed excellent antigenicity.Finally,we assessed and compared the immunogenicity of tg E with commercial v Oka LAV and Shingrix vaccine.We found that aluminum-adjuvanted tg E was immunogenic as compared with v Oka LAV.When adjuvanted with AS01B,a two-dose immunization of tg E showed comparable or better potency in antibody responses and cell-mediated immunity with those of the Shingrix vaccine at the same dosage,especially in terms of the proportion of IFN-γ-expressing CD4^(+)T cells.In conclusion,this method of E.coli-mediate tg E expression offers a cost-effective and scalable strategy to generate an ideal VZV g E immunogen for the development of both varicella and zoster vaccines.展开更多
The disinfected bacteria will be a photoreactivation under the irradiation of the sunlight,and the light intensity plays an important role in the bacteria resurrection.The effect of light intensity on photoreactivatio...The disinfected bacteria will be a photoreactivation under the irradiation of the sunlight,and the light intensity plays an important role in the bacteria resurrection.The effect of light intensity on photoreactivation of Escherichia coli(E.coli) and Enterococcus faecalis(E.faecalis) in secondary effluents which were disinfected respectively by pure UV and UV-TiO_2 was investigated.The results show that the disinfection efficiency of UV-TiO_2 is much higher than that of the pure UV disinfection.The photoreactivation rate of E.coli is much higher in pure UV disinfection than in UV-TiO_2 photocatalytic disinfection.Under high light intensity in UV-TiO_2 disinfection,high resurrection rate can be induced.However,a higher resurrection rate can be introduced even under low light intensity in pure UV disinfection alone.Meanwhile,UV-TiO_2 disinfection has a strong inhibition effect on E.faecalis photoreactivation.When the light intensity is lower than 21 μW/cm^2,nearly no resurrection of E.faecalis occurs after 72 h resurrection irradiation,and a little resurrection rate is observed only under a strong photoreactivating light intensity.展开更多
The increasing emergence of multi-drug resistant Escherichia coli(E.coli)has become a global concern,primarily due to the limitation of antimicrobial treatment options.Phage therapy has been considered as a promising ...The increasing emergence of multi-drug resistant Escherichia coli(E.coli)has become a global concern,primarily due to the limitation of antimicrobial treatment options.Phage therapy has been considered as a promising alternative for treating infections caused by multi-drug resistant E.coli.However,the application of phages as a promising antimicrobial agent is limited by their narrow host range and specificity.In this research,a recombinant T4-like phage,named WGqlae,has been obtained by changing the receptor specificity determinant region of gene 37,using a homologous recombination platform of T4-like phages established by our laboratory previously.The engineered phage WGqlae can lyse four additional hosts,comparing to its parental phages WG01 and QL01.WGqlae showed similar characteristics,including thermo and pH stability,optimal multiplicity of infection and one-step growth curve,to the donor phage QL01.In addition,sequencing results showed that gene 37 of recombinant phage WGqlae had genetically stable even after 20 generations.In planktonic test,phage WGqlae had significant antimicrobial effects on E.coli DE192 and DE205 B.The optical density at 600 nm(OD600)of E.coli in phage WGqlae treating group was significantly lower than that of the control group(P\0.01).Besides,phage WGqlae demonstrated an obvious inhibitory effect on the biofilm formation and the clearance of mature biofilms.Our study suggested that engineered phages may be promising candidates for future phage therapy applications against pathogenic E.coli in planktonic and biofilm forms.展开更多
The thermokinetic properties of the action of two kinds of lanthanum complexes [La(Hsal)2·(tch)]·2H2O and La(Hsal)2·(hq)(Hsal= C7H5O3,tch= C4H6NO2S,hq =C9H6NO)on growth metabolism of Escherichia coli we...The thermokinetic properties of the action of two kinds of lanthanum complexes [La(Hsal)2·(tch)]·2H2O and La(Hsal)2·(hq)(Hsal= C7H5O3,tch= C4H6NO2S,hq =C9H6NO)on growth metabolism of Escherichia coli were studied by a TAM air isothermal calorimeter at 37.00℃.The maximum heat output power Pmax,growth rate constant k,generation timestG,inhibitive ratio I(%) and half inhibition concentration cI,50,were obtained respectively.The results showed that complex[La(Hsal)2·(tch)]·2H2O possessed the bi-directional biological effect.It inhibited the growth of the E.coli at lower concentration but stimulated the growth at higher concentration.The complexes La(Hsal)2·(hq) possessed inhibitory effect.Inhibitory effect of La(Hsal)2·(hq)(cI,50=1.81 mg·L-1) was stronger than that of [La(Hsal)2·(tch)]·2H2O(CI,50=9.78mg·L-1).展开更多
文摘BACKGROUND:The virulent factors of Escherichia coli(E.coli) play an important role in the process of pathopoiesis.The study aimed to compare drug-resistant genes and virulence genes between extended spectrum β-lactamases(ESBLs)-producing E.coli and non-ESBLs-producing E.coli to provide a reference for physicians in management of hospital infection.METHODS:From October 2010 to August 2011,96 drug-resistant strains of E.coli isolated were collected from the specimens in Qingdao Municipal Hospital,Qingdao,China.These bacteria strains were divided into a ESBLs-producing group and a non-ESBLs-producing group.Drug sensitivity tests were performed using the Kirby-Bauer(K-B) method.Disinfectant gene,qacEA1-sull and 8 virulence genes(CNF2,hlyA,eaeA,VT1,est,bfpA,elt,and CNF1) were tested by polymerase chain reaction(PCR).RESULTS:Among the 96 E.coli isolates,the ESBLs-producing E.coli comprised 46(47.9%)strains and the non-ESBLs-producing E.coli consisted of 50(52.1%) strains.The detection rates of multiple drug-resistant strain,qacEA1-sull,CNF2,hlyA,eaeA,VT1,est,bfpA,elt,and CNF1 in 46ESBLs-producing E.coli isolates were 89.1%,76.1%,6.5%,69.6%,69.6%,89.1%,10.9%,26.1%,8.7%,and 19.6%,respectively.In the non-ESBLs-producing E.coli strains,the positive rates of multiple drug-resistant strain,qacEA1-sull,CNF2,hlyA,eaeA,VT1,est,bfpA,elt,and CNF1 were 62.0%,80.0%,16.0%,28.0%,64.0%,38.0%,6.0%,34.0%,10.0%,and 24.0%,respectively.The difference in the detection rates of multiple drug-resistant strain,hlyA and VT1 between the ESBLs-producing E.coli strains and the non-ESBLs-producing E.coli strains was statistically significant(P<0.05).CONCLUSION:The positive rate of multiple drug-resistant strains is higher in the ESBLsproducing strains than in the non-ESBLs-producing strains.The expression of some virulence genes hlyA and VT1 varies between the ESBLs-producing strains and the non-ESBLs-producing strains.Increased awareness of clinicians and enhanced testing by laboratories are required to reduce treatment failures and prevent the spread of multiple drug-resistant strains.
基金Fundação de Amparo a Pesquisa do Estado de São Paulo(FAPESP)and the Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq),São Paulo,Brazil for PhD scholarship(Process N°.141086/2015-7)financial support(Process No.870243/1997-7).
文摘The UV irradiation is used for removing Antibiotic Resistant Bacteria(ARB)and Antibiotic Resistance Genes(ARG)from wastewater treatment.Bacteriophages are viruses that infect within bacteria,are recognized for bacterial control.The influence of some parameters in quantification and performance influencing of pathogen demobilization could be considered in disinfection of wastewater.The comparison of Polyvalent phage(NE1)versus Coliphage(NE4)in suppressing a bacterium Escherichia coli(NDM-1:b-lactam-resistant)with UV irradiation was observed the efficacy in reduction of cells in the disinfection and parameter process.The results with the effect of UV-C irradiation on NDM-1 infected with 1%of NE4 showed a decrease of cells from 8×10^(6)to 2×10^(5)in 60 min with UV-C dose.The NDM1(E.coli)was infected with 1%of NE4(Polyvalent Phage)under magnetic stirring for 1 h,the cells count was 8×10^(6).After 1 h in UV-C e×posure,the cells number reached 3×10^(5).The NDM1 that was e×posed in 1 h of UV-C irradiation and then was infected with 1%of NE4.Cells counting were done 24 h after this procedure.These cells were e×posed in UV-C and showed a reduction in the number of cells from 1×10^(8)to 4×10^(5)after 60 min.The results indicate that bacteriophages can mitigate bacteria species,and combined the conventional water disinfection technologies that can support the microbial safety control strategies.
基金基金项目：国家重点基础研究发展计划（973计划）资助项目（2011CB933202）中围科学院战略性先导科技专项课题资助项目（XDA06020101）+3 种基金国家杰出青年自然基金资助项目（61125105）国家高技术研究发展计划（863计划）资助项目（2009AA03Z411）中国科学院科研装备研制资助项目（Y2010015）国家自然科学基金资助项目（61027001,61002037）.Acknowledgements This work was supported by the Major National Scientific Research Plan （No.2011CB933202）, ＂Strategic Priority Research Program＂ of the Chinese Academy of Sciences （No.XDA06020101）, the National Science Fund for Distinguished Young Scholar （No. 61125105）, the Hi-Tech R＆D Program of China （No. 2009AA03Z411）, the CAS Program （No.Y2010015） and the National Natural Science Foundation of China （No. 61027001, No. 61002037）.
基金supported by the National Key Research and Development Program of China(2021YFC2301404)the National Natural Science Foundation of China(81991490)+2 种基金the Industry-University-Academy Cooperation Program of Xiamen(2022CXY0107)the Principal Fund(20720220006 and 20720220004)CAMS Innovation Fund for Medical Sciences(2019RU022)。
文摘Varicella-zoster virus(VZV)is a highly infectious agent responsible for both varicella and herpes zoster disease.Despite high efficacy,there remain safety and accessibility concerns with the licensed vaccines.Here,we sought to produce a VZV g E immunogen using an E.coli expression system.We found that the soluble expression and yield of g E protein could be enhanced via C-terminal truncations to the protein,thereby facilitating a robust and scalable purification process for the purpose of vaccine manufacturing.The lead truncated g E(aa 31–358),hereafter referred to as tg E,was a homogenous monomer in solution and showed excellent antigenicity.Finally,we assessed and compared the immunogenicity of tg E with commercial v Oka LAV and Shingrix vaccine.We found that aluminum-adjuvanted tg E was immunogenic as compared with v Oka LAV.When adjuvanted with AS01B,a two-dose immunization of tg E showed comparable or better potency in antibody responses and cell-mediated immunity with those of the Shingrix vaccine at the same dosage,especially in terms of the proportion of IFN-γ-expressing CD4^(+)T cells.In conclusion,this method of E.coli-mediate tg E expression offers a cost-effective and scalable strategy to generate an ideal VZV g E immunogen for the development of both varicella and zoster vaccines.
基金Projects(51174090,51168026)supported by the National Natural Science Foundation of China
文摘The disinfected bacteria will be a photoreactivation under the irradiation of the sunlight,and the light intensity plays an important role in the bacteria resurrection.The effect of light intensity on photoreactivation of Escherichia coli(E.coli) and Enterococcus faecalis(E.faecalis) in secondary effluents which were disinfected respectively by pure UV and UV-TiO_2 was investigated.The results show that the disinfection efficiency of UV-TiO_2 is much higher than that of the pure UV disinfection.The photoreactivation rate of E.coli is much higher in pure UV disinfection than in UV-TiO_2 photocatalytic disinfection.Under high light intensity in UV-TiO_2 disinfection,high resurrection rate can be induced.However,a higher resurrection rate can be introduced even under low light intensity in pure UV disinfection alone.Meanwhile,UV-TiO_2 disinfection has a strong inhibition effect on E.faecalis photoreactivation.When the light intensity is lower than 21 μW/cm^2,nearly no resurrection of E.faecalis occurs after 72 h resurrection irradiation,and a little resurrection rate is observed only under a strong photoreactivating light intensity.
基金supported by Grants from the National Natural Science Foundation of China(U1803109)Key research and development plan of Jiangsu province(BE2019304)+2 种基金National Key R&D Program of China(2018YFC1602500)the Central University Basic Scientific Research Fund-Animal pathogenic bacteria(KYZ201846)Jiangsu modern agriculture(waterfowl)industrial technology system disease prevention and control innovation team(JATS[2018]222)
文摘The increasing emergence of multi-drug resistant Escherichia coli(E.coli)has become a global concern,primarily due to the limitation of antimicrobial treatment options.Phage therapy has been considered as a promising alternative for treating infections caused by multi-drug resistant E.coli.However,the application of phages as a promising antimicrobial agent is limited by their narrow host range and specificity.In this research,a recombinant T4-like phage,named WGqlae,has been obtained by changing the receptor specificity determinant region of gene 37,using a homologous recombination platform of T4-like phages established by our laboratory previously.The engineered phage WGqlae can lyse four additional hosts,comparing to its parental phages WG01 and QL01.WGqlae showed similar characteristics,including thermo and pH stability,optimal multiplicity of infection and one-step growth curve,to the donor phage QL01.In addition,sequencing results showed that gene 37 of recombinant phage WGqlae had genetically stable even after 20 generations.In planktonic test,phage WGqlae had significant antimicrobial effects on E.coli DE192 and DE205 B.The optical density at 600 nm(OD600)of E.coli in phage WGqlae treating group was significantly lower than that of the control group(P\0.01).Besides,phage WGqlae demonstrated an obvious inhibitory effect on the biofilm formation and the clearance of mature biofilms.Our study suggested that engineered phages may be promising candidates for future phage therapy applications against pathogenic E.coli in planktonic and biofilm forms.
文摘The thermokinetic properties of the action of two kinds of lanthanum complexes [La(Hsal)2·(tch)]·2H2O and La(Hsal)2·(hq)(Hsal= C7H5O3,tch= C4H6NO2S,hq =C9H6NO)on growth metabolism of Escherichia coli were studied by a TAM air isothermal calorimeter at 37.00℃.The maximum heat output power Pmax,growth rate constant k,generation timestG,inhibitive ratio I(%) and half inhibition concentration cI,50,were obtained respectively.The results showed that complex[La(Hsal)2·(tch)]·2H2O possessed the bi-directional biological effect.It inhibited the growth of the E.coli at lower concentration but stimulated the growth at higher concentration.The complexes La(Hsal)2·(hq) possessed inhibitory effect.Inhibitory effect of La(Hsal)2·(hq)(cI,50=1.81 mg·L-1) was stronger than that of [La(Hsal)2·(tch)]·2H2O(CI,50=9.78mg·L-1).
