In order to reduce deleterious effect on environment,human health and facilities caused by original sulfides, more attention should be paid to biodesulfurization studying for fossil fuels. In this work, eight isolates...In order to reduce deleterious effect on environment,human health and facilities caused by original sulfides, more attention should be paid to biodesulfurization studying for fossil fuels. In this work, eight isolates were characterized by several DNA-based methods such as BOX element polymerase chain reaction( BOX-PCR), enterobacterial repetitive intergenic consensus( ERIC)-PCR and random amplification of polymorphic DNA( RAPD)-PCR. The desulfurization performance was determined by micro-coulometric method,Gibb's assay and barium sulfate test. It was found out that ERIC-PCR displays a much higher inter-strain heterogeneity compared with using BOX. The length of the primer didnot play the most important role in bacterial classification. The combination of the analysis of repetitive-sequence-based polymerase chain reaction ngerprinting and 16 S r DNA was able to provide more effective way in the separation and identification of bacteria.According to the analysis of 16 S r DNA,the more efficient desulfurization strain should belong to Klebsiella variicola.展开更多
Background:Bacterial diarrhea is one of the most common causes for medical consultations,mortality and morbidity in the world.Diarrheagenic Escherichia coli(DEC)and non-typhoidal Salmonella(NTS)are major intestinal pa...Background:Bacterial diarrhea is one of the most common causes for medical consultations,mortality and morbidity in the world.Diarrheagenic Escherichia coli(DEC)and non-typhoidal Salmonella(NTS)are major intestinal pathogens in developing countries,and the indiscriminate use of antibiotics has greatly contributed to resistant strains.Hence,the aim of the present study is to identify the antimicrobial resistance patterns and the molecular characteristics of DEC and NTS in southwest,China.Methods:1121 diarrheal patients and 319 non-diarrheal subjects across all age groups were recruited from four sentinel hospitals from June 2014 to July 2015 in Kunming City,Yunnan Province.Each stool specimen was collected to detect DEC and NTS with standard microbiological and molecular methods.Antimicrobial resistance testing was performed with the Kirby-Bauer disk diffusion method,and the standards for antimicrobial susceptibility testing complied with the Clinical and Laboratory Standards Institute(CLSI).Molecular characterization of strains was carried out using pulsed-field gel electrophoresis(PFGE).A structured questionnaire was used to record basic epidemiological data(e.g.sex,age,residence,season,etc.).Data were analyzed using Chi-square or Fisher’s exact test.Results:DEC was detected in 127(11.33%)diarrhea cases and 9(2.82%)non-diarrheal cases(χ^(2)=20.69,P<0.001,OR=4.36,95%CI:2.19-8.65),and the prevalence of NTS isolated from diarrhea cases was higher than that of non-diarrheal cases across all age groups(n=42,3.75%,n=1,0.31%,χ^(2)=10.10,P=0.002,OR=12.38,95%CI:1.70-90.29).The rates of resistance to ten antibiotics of DEC and NTS showed significant differences(χ^(2)=386.77,P<0.001;χ^(2)=191.16,P<0.001).The rates of resistance to Amoxicillin and Clavulafiate(AMC),Cephalothin(CEP),Gentamicin(GEN)and Sulfamethoxazole-Trimethoprim(SXT)of DEC isolated from diarrhea cases were higher than those of NTS isolated from diarrhea patients(37.01%vs 14.29%,χ^(2)=7.57,P=0.006;29.92%vs 11.90%,χ^(2)=5.40,P=0.02;37.01%vs 11.90%,χ^(2)=5.80,P=0.016;62.20%vs 26.19%,χ^(2)=16.44,P<0.001;respectively).Ciprofloxacin(CIP)was the most sensitive antibiotic for DEC and NTS strains isolated from diarrhea cases.Resistance rates of DEC isolates from cases and controls to more than three kinds antimicrobials(multidrug resistance,MDR)showed no significant differences(81.10%vs 88.89%,P=0.33).Pulsotype patterns of DEC strains were highly diverse;however,the pulsotype pattern of NTS strains was closely related to the serotype.The pattern of S.enteritidis was highly similar,but the S.enterica Typhimurium strain was discrete.Conclusions:Antibiotic resistance of Enterobacteriaceae is of great concern.The societal effects of antibiotic use justify strict monitoring to combat increases in antimicrobial resistance.Molecular epidemiology and systematic epidemiological investigation can provide accurate evidence for tracking the infection source.展开更多
基金National Natural Science Foundations of China(Nos.41302079,21176145)Project of Shandong Province Higher Educational Science and Technology Program,China(No.J13LD54)
文摘In order to reduce deleterious effect on environment,human health and facilities caused by original sulfides, more attention should be paid to biodesulfurization studying for fossil fuels. In this work, eight isolates were characterized by several DNA-based methods such as BOX element polymerase chain reaction( BOX-PCR), enterobacterial repetitive intergenic consensus( ERIC)-PCR and random amplification of polymorphic DNA( RAPD)-PCR. The desulfurization performance was determined by micro-coulometric method,Gibb's assay and barium sulfate test. It was found out that ERIC-PCR displays a much higher inter-strain heterogeneity compared with using BOX. The length of the primer didnot play the most important role in bacterial classification. The combination of the analysis of repetitive-sequence-based polymerase chain reaction ngerprinting and 16 S r DNA was able to provide more effective way in the separation and identification of bacteria.According to the analysis of 16 S r DNA,the more efficient desulfurization strain should belong to Klebsiella variicola.
基金Pathogens identified were supported by the postdoctoral research funding of SX-Z from Guangzhou Women and Children’s Medical Center(5001–3001075)The field epidemiological investigation was supported from National Natural Science Foundation of China(Grant number:81473022)+2 种基金The antibiotic resistance testing and the experiment of molecular characterization of pathogens were supported by National Key Research and Development Project(No.2016YFC1202000)The data analysis was conducted by E.Serrano who was funded by the Spanish Ministerio de Economia y Competitividad(MINECO)through a Ramon y Cajal agreement(RYC-2016-21120)R.Tinoco-Torres was supported by a post-doctoral grant by the Portuguese Fundacao para a Ciencia e a Tecnologia FCT(SFRH/BPD/112482/2015).
文摘Background:Bacterial diarrhea is one of the most common causes for medical consultations,mortality and morbidity in the world.Diarrheagenic Escherichia coli(DEC)and non-typhoidal Salmonella(NTS)are major intestinal pathogens in developing countries,and the indiscriminate use of antibiotics has greatly contributed to resistant strains.Hence,the aim of the present study is to identify the antimicrobial resistance patterns and the molecular characteristics of DEC and NTS in southwest,China.Methods:1121 diarrheal patients and 319 non-diarrheal subjects across all age groups were recruited from four sentinel hospitals from June 2014 to July 2015 in Kunming City,Yunnan Province.Each stool specimen was collected to detect DEC and NTS with standard microbiological and molecular methods.Antimicrobial resistance testing was performed with the Kirby-Bauer disk diffusion method,and the standards for antimicrobial susceptibility testing complied with the Clinical and Laboratory Standards Institute(CLSI).Molecular characterization of strains was carried out using pulsed-field gel electrophoresis(PFGE).A structured questionnaire was used to record basic epidemiological data(e.g.sex,age,residence,season,etc.).Data were analyzed using Chi-square or Fisher’s exact test.Results:DEC was detected in 127(11.33%)diarrhea cases and 9(2.82%)non-diarrheal cases(χ^(2)=20.69,P<0.001,OR=4.36,95%CI:2.19-8.65),and the prevalence of NTS isolated from diarrhea cases was higher than that of non-diarrheal cases across all age groups(n=42,3.75%,n=1,0.31%,χ^(2)=10.10,P=0.002,OR=12.38,95%CI:1.70-90.29).The rates of resistance to ten antibiotics of DEC and NTS showed significant differences(χ^(2)=386.77,P<0.001;χ^(2)=191.16,P<0.001).The rates of resistance to Amoxicillin and Clavulafiate(AMC),Cephalothin(CEP),Gentamicin(GEN)and Sulfamethoxazole-Trimethoprim(SXT)of DEC isolated from diarrhea cases were higher than those of NTS isolated from diarrhea patients(37.01%vs 14.29%,χ^(2)=7.57,P=0.006;29.92%vs 11.90%,χ^(2)=5.40,P=0.02;37.01%vs 11.90%,χ^(2)=5.80,P=0.016;62.20%vs 26.19%,χ^(2)=16.44,P<0.001;respectively).Ciprofloxacin(CIP)was the most sensitive antibiotic for DEC and NTS strains isolated from diarrhea cases.Resistance rates of DEC isolates from cases and controls to more than three kinds antimicrobials(multidrug resistance,MDR)showed no significant differences(81.10%vs 88.89%,P=0.33).Pulsotype patterns of DEC strains were highly diverse;however,the pulsotype pattern of NTS strains was closely related to the serotype.The pattern of S.enteritidis was highly similar,but the S.enterica Typhimurium strain was discrete.Conclusions:Antibiotic resistance of Enterobacteriaceae is of great concern.The societal effects of antibiotic use justify strict monitoring to combat increases in antimicrobial resistance.Molecular epidemiology and systematic epidemiological investigation can provide accurate evidence for tracking the infection source.
