To show the remediation of Pb-resistant bacteria to Pb polluted soil, several indices including microbial counts, soil enzyme activity, microbial community diversity and soil Pb concentration were investigated. Two Pb...To show the remediation of Pb-resistant bacteria to Pb polluted soil, several indices including microbial counts, soil enzyme activity, microbial community diversity and soil Pb concentration were investigated. Two Pb-resistant bacteria were filtrated and identified by previous study as Bacillus pumilus and Pseudomonas aeruginosa (GeneBank Accession No. FJ402988 and GU017676) and inoculated to soil planted with cabbages. Soil with different Pb application rates were incubated for a period of 0, 12, 24, 36, 48 days in greenhouse. Results indicated the count of bacteria in 1000 mg/kg Pb treated soil greatly affected by inoculating Pb-resistant bacteria, which was raised about 237% and 347% compared with control. Soil urease and invertase were intensified 37.9% and 65.6% after inoculation compared with control. Phosphatase activity was inhibited by inoculation of Bacillus pumilus. Catalase activity was intensified about 64.2% in 24 days incubation but decrease in the following days. Microbial community diversity analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) also proved that the samples inoculated with Pb-resistant bacteria exhibited more bands and intensity in DGGE patterns compared with uninoculated ones. For Pb-resistant bacteria inoculated samples, the reduction of Pb concentration in rhizospheric soil was 15 mg/kg at least and 42 mg/kg at most, and Pseudomonas aeruginosa showed a better tolerance to high Pb concentration and stronger remediation ability. It was concluded that remediation of Pb polluted soil can be promoted by the two Pb-resistant bacteria.展开更多
Resistance/sensitivity to polymyxin-B(PB)antibiotic has been employed as one among other epidemiologically relevant biotyping-scheme for Vibrio cholerae into Classical/El Tor biotypes.However,recent studies have re-ve...Resistance/sensitivity to polymyxin-B(PB)antibiotic has been employed as one among other epidemiologically relevant biotyping-scheme for Vibrio cholerae into Classical/El Tor biotypes.However,recent studies have re-vealed some pitfalls bordering on PB-sensitivity/resistance(PBR/S)necessitating study.Current study assesses the PBR/S cosmopolitan prevalence,epidemiology/distribution among O1/O139 and nonO1/nonO139 V.cholerae strains.Relevant databases(Web of Science,Scopus and PubMed)were searched to retrieve data from environ-mental and clinical samples employing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA).Random-effect-model(REM)and common-effect-model(CEM)of meta-analysis was performed to de-termine prevalence of PBR/S V.cholerae strains,describe the cosmopolitan epidemiological potentials and biotype relevance.Heterogeneity was determined by meta-regression and subgroup analyses.The pooled analyzed iso-lates from articles(7290),with sensitive and resistance are 2219(30.44%)and 5028(69.56%).Among these PB-sensitive strains,more than 1944(26.67%)were O1 strains,132(1.81%)were nonO1 strains while mis-reported Classical biotype were 2080(28.53)respectively indicating potential spread of variant/dual biotype.A significant PB-resistance was observed in the models(CEM=0.66,95%CI[0.65;0.68],p-value=0.001;REM=0.83[0.74;0.90],p=0.001)as both models had a high level of heterogeneity(I^(2)=98.0%;^(2)_(df=33)=1755.09,Qp=2.4932).Egger test(z=5.4017,p<0.0001)reveal publication bias by funnel plot asymmetry.The subgroup analysis for continents(Asia,Africa)and sources(acute diarrhea)revealed(98%CI(0.73;0.93);55%CI(0.20;0.86)),and 92%CI(0.67;0.98).The Epidemiological prevalence for El tor/variant/dual biotype showed 88%CI(0.78;0.94)with O1 strains at 88%CI(0.78;0.94).Such global prevalence,distribution/spread of phenotypes/genotypes ne-cessitates updating the decades-long biotype classification scheme.An antibiotic stewardship in the post antibiotic era is suggestive/recommended.Also,there is need for holistic monitoring/evaluation of clinical/epidemiological relevance of the disseminating strains in endemic localities.展开更多
文摘To show the remediation of Pb-resistant bacteria to Pb polluted soil, several indices including microbial counts, soil enzyme activity, microbial community diversity and soil Pb concentration were investigated. Two Pb-resistant bacteria were filtrated and identified by previous study as Bacillus pumilus and Pseudomonas aeruginosa (GeneBank Accession No. FJ402988 and GU017676) and inoculated to soil planted with cabbages. Soil with different Pb application rates were incubated for a period of 0, 12, 24, 36, 48 days in greenhouse. Results indicated the count of bacteria in 1000 mg/kg Pb treated soil greatly affected by inoculating Pb-resistant bacteria, which was raised about 237% and 347% compared with control. Soil urease and invertase were intensified 37.9% and 65.6% after inoculation compared with control. Phosphatase activity was inhibited by inoculation of Bacillus pumilus. Catalase activity was intensified about 64.2% in 24 days incubation but decrease in the following days. Microbial community diversity analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) also proved that the samples inoculated with Pb-resistant bacteria exhibited more bands and intensity in DGGE patterns compared with uninoculated ones. For Pb-resistant bacteria inoculated samples, the reduction of Pb concentration in rhizospheric soil was 15 mg/kg at least and 42 mg/kg at most, and Pseudomonas aeruginosa showed a better tolerance to high Pb concentration and stronger remediation ability. It was concluded that remediation of Pb polluted soil can be promoted by the two Pb-resistant bacteria.
基金funds provided by African German Network of Excellence in Science 2022 (AGNES-2022).
文摘Resistance/sensitivity to polymyxin-B(PB)antibiotic has been employed as one among other epidemiologically relevant biotyping-scheme for Vibrio cholerae into Classical/El Tor biotypes.However,recent studies have re-vealed some pitfalls bordering on PB-sensitivity/resistance(PBR/S)necessitating study.Current study assesses the PBR/S cosmopolitan prevalence,epidemiology/distribution among O1/O139 and nonO1/nonO139 V.cholerae strains.Relevant databases(Web of Science,Scopus and PubMed)were searched to retrieve data from environ-mental and clinical samples employing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA).Random-effect-model(REM)and common-effect-model(CEM)of meta-analysis was performed to de-termine prevalence of PBR/S V.cholerae strains,describe the cosmopolitan epidemiological potentials and biotype relevance.Heterogeneity was determined by meta-regression and subgroup analyses.The pooled analyzed iso-lates from articles(7290),with sensitive and resistance are 2219(30.44%)and 5028(69.56%).Among these PB-sensitive strains,more than 1944(26.67%)were O1 strains,132(1.81%)were nonO1 strains while mis-reported Classical biotype were 2080(28.53)respectively indicating potential spread of variant/dual biotype.A significant PB-resistance was observed in the models(CEM=0.66,95%CI[0.65;0.68],p-value=0.001;REM=0.83[0.74;0.90],p=0.001)as both models had a high level of heterogeneity(I^(2)=98.0%;^(2)_(df=33)=1755.09,Qp=2.4932).Egger test(z=5.4017,p<0.0001)reveal publication bias by funnel plot asymmetry.The subgroup analysis for continents(Asia,Africa)and sources(acute diarrhea)revealed(98%CI(0.73;0.93);55%CI(0.20;0.86)),and 92%CI(0.67;0.98).The Epidemiological prevalence for El tor/variant/dual biotype showed 88%CI(0.78;0.94)with O1 strains at 88%CI(0.78;0.94).Such global prevalence,distribution/spread of phenotypes/genotypes ne-cessitates updating the decades-long biotype classification scheme.An antibiotic stewardship in the post antibiotic era is suggestive/recommended.Also,there is need for holistic monitoring/evaluation of clinical/epidemiological relevance of the disseminating strains in endemic localities.
