Difference in the genomic compositions of prokaryotes is the basis of the diversity in their biological characters. However, besides their flora-or strain-specific genes,those floras with closer relationship in the ev...Difference in the genomic compositions of prokaryotes is the basis of the diversity in their biological characters. However, besides their flora-or strain-specific genes,those floras with closer relationship in the evolution also have conserved “backbone sequences”, which reveal the marks of their origin and evolution, and these “backbone sequences”are just the basis of their elementary living abilities and common biological properties. Shigella is very closely related to E. coli in the origin and evolution, and may turn out to belong to the same genus. In this study, a microarray containing E. coli K-12 whole genome and Sf301 specific ORFs is used to investigate the genomic components of four Shigella strains. The results indicate that 16%-22% K-12 ORFs sequences are not detected in the genome of Shigella strains while the genome of Shigella contains at least 2800 conserved ORFs, which compose the common “backbone sequences”.Advanced analysis indicated that the “backbone sequences”are the essential components in maintaining the normal physiological activities of intestinal bacteria. Furthermore,only 20% Sf301-specific ORFs exist in other strains simultaneously, which demonstrate the great genome heterogeneity and the genetic diversity among the strains.展开更多
Objective:To investigate the antimicrobial resistance patterns and prevalence of integrons in Shigella species isolated from children with diarrhea in southwest Iran.Methods:In this study,1530 stool samples were colle...Objective:To investigate the antimicrobial resistance patterns and prevalence of integrons in Shigella species isolated from children with diarrhea in southwest Iran.Methods:In this study,1530 stool samples were collected from children under 15 years with diarrhea referred to teaching hospitals in Ahvaz and Abadan,southwest Iran.Shigella spp.were identified by standard biochemical tests and PCR.The antibiotic resistance pattern of all Shigella isolates was determined by the disk diffusion method and minimum inhibitory concentration(MIC)by E-test.Results:Of 1530 stool samples,91(5.9%,91/1530)were positive for Shigella spp.the most common Shigella isolates were Shigella flexneri 47(51.6%,47/1530).Antibiotic susceptibility tests showed that the highest antibiotic resistance was related to trimethoprimsulfamethoxazole(87.9%,80/91)and ampicillin(86.8%,79/91).Multiplex PCR results revealed that 56%and 86.9%of Shigella isolates carried integron classⅠand integron classⅡgenes,respectively.None of the isolates included the integron classⅢgene.Conclusions:The high prevalence of multi-drug resistance in Shigella isolates in our area increases the concerns about dissemination of the antibiotic-resistant isolates in this bacterium.展开更多
目的使用免疫磁分离-双重荧光定量PCR方法实现对鲜猪肉中金黄色葡萄球菌和志贺氏菌的同时、快速检测。方法在37℃的条件下,利用特异性免疫磁球从250 m L循环体系中快速、有效地捕获目标菌。再通过特异性的引物与探针,对沙门氏菌和志贺...目的使用免疫磁分离-双重荧光定量PCR方法实现对鲜猪肉中金黄色葡萄球菌和志贺氏菌的同时、快速检测。方法在37℃的条件下,利用特异性免疫磁球从250 m L循环体系中快速、有效地捕获目标菌。再通过特异性的引物与探针,对沙门氏菌和志贺氏菌进行双重荧光定量PCR检测。结果本研究方法针对鲜猪肉中沙门氏菌和志贺氏菌的检测限分别达到3.4 cfu/g和9.4 cfu/g。方法总体灵敏度、特异性和准确度均达到100%。此外,通过对30组实际样品的检测,该方法与传统标准方法的结果保持一致。结论本研究建立的免疫磁分离-双重荧光定量PCR方法比国标方法更快速和高效,适用于鲜猪肉中沙门氏菌和志贺氏菌的快速检测。展开更多
文摘Difference in the genomic compositions of prokaryotes is the basis of the diversity in their biological characters. However, besides their flora-or strain-specific genes,those floras with closer relationship in the evolution also have conserved “backbone sequences”, which reveal the marks of their origin and evolution, and these “backbone sequences”are just the basis of their elementary living abilities and common biological properties. Shigella is very closely related to E. coli in the origin and evolution, and may turn out to belong to the same genus. In this study, a microarray containing E. coli K-12 whole genome and Sf301 specific ORFs is used to investigate the genomic components of four Shigella strains. The results indicate that 16%-22% K-12 ORFs sequences are not detected in the genome of Shigella strains while the genome of Shigella contains at least 2800 conserved ORFs, which compose the common “backbone sequences”.Advanced analysis indicated that the “backbone sequences”are the essential components in maintaining the normal physiological activities of intestinal bacteria. Furthermore,only 20% Sf301-specific ORFs exist in other strains simultaneously, which demonstrate the great genome heterogeneity and the genetic diversity among the strains.
基金supported by the Vice-Chancellor for Research grant(Grant No.U98-564)of Abadan University of Medical Science
文摘Objective:To investigate the antimicrobial resistance patterns and prevalence of integrons in Shigella species isolated from children with diarrhea in southwest Iran.Methods:In this study,1530 stool samples were collected from children under 15 years with diarrhea referred to teaching hospitals in Ahvaz and Abadan,southwest Iran.Shigella spp.were identified by standard biochemical tests and PCR.The antibiotic resistance pattern of all Shigella isolates was determined by the disk diffusion method and minimum inhibitory concentration(MIC)by E-test.Results:Of 1530 stool samples,91(5.9%,91/1530)were positive for Shigella spp.the most common Shigella isolates were Shigella flexneri 47(51.6%,47/1530).Antibiotic susceptibility tests showed that the highest antibiotic resistance was related to trimethoprimsulfamethoxazole(87.9%,80/91)and ampicillin(86.8%,79/91).Multiplex PCR results revealed that 56%and 86.9%of Shigella isolates carried integron classⅠand integron classⅡgenes,respectively.None of the isolates included the integron classⅢgene.Conclusions:The high prevalence of multi-drug resistance in Shigella isolates in our area increases the concerns about dissemination of the antibiotic-resistant isolates in this bacterium.
文摘目的使用免疫磁分离-双重荧光定量PCR方法实现对鲜猪肉中金黄色葡萄球菌和志贺氏菌的同时、快速检测。方法在37℃的条件下,利用特异性免疫磁球从250 m L循环体系中快速、有效地捕获目标菌。再通过特异性的引物与探针,对沙门氏菌和志贺氏菌进行双重荧光定量PCR检测。结果本研究方法针对鲜猪肉中沙门氏菌和志贺氏菌的检测限分别达到3.4 cfu/g和9.4 cfu/g。方法总体灵敏度、特异性和准确度均达到100%。此外,通过对30组实际样品的检测,该方法与传统标准方法的结果保持一致。结论本研究建立的免疫磁分离-双重荧光定量PCR方法比国标方法更快速和高效,适用于鲜猪肉中沙门氏菌和志贺氏菌的快速检测。
