Objective To establish and compare the pulsed-field gel electrophoresis (PFGE), multiple-locus variable number tandem repeat analysis (MLVA) and automated ribotyping for subtyping of Citrobacter strains. Methods PFGE ...Objective To establish and compare the pulsed-field gel electrophoresis (PFGE), multiple-locus variable number tandem repeat analysis (MLVA) and automated ribotyping for subtyping of Citrobacter strains. Methods PFGE protocol was optimized in terms of plug preparation procedure, restriction enzymes and configuration of electrophoretic parameters. MLVA method was evaluated by finding variable number tandem repeats in two genomes of Citrobacter strains. The ribotyping was performed by using the automated RiboPrinter system. Results We optimized the plug preparation procedure, focused on the cell suspension concentration (turbidity of 2.5 to 3.5), SDS addition (no SDS needed) and lysis time (1 h), and selected the appropriate restriction enzyme (XbaI) and the electrophoretic parameters (1.0 s-20.0 s for 19 h) of PFGE. There was nearly no discriminatory power of MLVA between Citrobacter strains. For 51 Citrobacter strains, automated ribotyping gave a D-value of 0.9945, while PFGE gave a D-value of 0.9969. Both PFGE and automated ribotyping clustered strains from the same sources (with the same species from the same place at the same time identified as the same source) and divided strains from different sources (from different years, places and hosts) into different subtypes. Conclusion PFGE protocol established in this paper and automated ribotyping are suitable for application in Citrobacter subtyping.展开更多
This experiment was conducted to clarify species and drug resistance of pathogen from the diseased Procambarus clarkia. Pathogenic bacteria from hepatopancreas of the diseased P. clarkia were examined using convention...This experiment was conducted to clarify species and drug resistance of pathogen from the diseased Procambarus clarkia. Pathogenic bacteria from hepatopancreas of the diseased P. clarkia were examined using conventional methods,and then were isolated. The further tests and analysis of the isolated strain were developed,including the regression experiment to P. clarkia,the morphology,physiological and biochemical characteristics,sequence analysis of their 16 S rRNA and gyr B genes,and the susceptibility test to antibiotics. Large colonies with similar morphology and color were obtained. Strain X120523 was identified as Citrobacter freundii,proved to have strong pathogenicity,and was susceptible to quinolones and aminoglycosides.展开更多
Pathogenic strains of E. coli including enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli (EHEC), enterotoxigenic E. coli (ETEC) are principle causes for diarrhoea in many parts of the globe. Citrobacter rode...Pathogenic strains of E. coli including enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli (EHEC), enterotoxigenic E. coli (ETEC) are principle causes for diarrhoea in many parts of the globe. Citrobacter rodentium (C. rodentium), a gram negative bacterium, is a murine pathogen that also utilizes type III secretion system and similar virulence factors to EPEC and EHEC and forms comparable attaching/effacing lesions in the intestines as EPEC and EHEC. The infection caused by C. rodentium in mice is usually self-limiting and results in only minor systemic effects with higher mortality in some susceptible mouse strains. All these characteristics have made the bacteria a commonly used model to study host immune responses to pathogenic E. coli infection. In this review, we focus on the impact of virulence factors of the pathogen;different immune components involved in the immune response and summarize their role during C. rodentium infection.展开更多
Rationale:Infectious keratopathy is an ocular emergency with the potential to cause irreversible blindness.Patient's concerns:A 63-year-old diabetic man presented with a 3-day history of painful red right eye.He h...Rationale:Infectious keratopathy is an ocular emergency with the potential to cause irreversible blindness.Patient's concerns:A 63-year-old diabetic man presented with a 3-day history of painful red right eye.He had a history of multiple ocular surgeries in the affected eye without recent ocular trauma.Diagnosis:Infective crystalline keratopathy secondary to Citrobacter koseri.Interventions:Topical corticosteroids were discontinued,and dual topical antibiotic therapy of moxifloxacin 5%and gentamycin 0.3%were applied.Outcomes:Twelve hours after the start of treatment,the crystalline nature of the infiltrate disappeared,with enlargement of the epithelial defect.The antibiotic regime was continued and the lesion healed within a week of presentation with residual scarring.Lessons:Infective crystalline keratopathy classically presents with intrastromal branching fern-like opacities and minimal anterior segment inflammation in an immunosuppressed eye.The mainstay of management is corticosteroid discontinuation and the administration of empirical antibiotics until the results of the culture and sensitivity are available.In Citrobacter-related cases,treatment may result in a suppurative appearance before healing of the lesion.展开更多
Medicinal plants have been presented as a valuable source of preservation of human health. In special, Stryphnodendron barbatiman has been employed due to its antimicrobial activity. This plant is rich in tannins and ...Medicinal plants have been presented as a valuable source of preservation of human health. In special, Stryphnodendron barbatiman has been employed due to its antimicrobial activity. This plant is rich in tannins and has been used in popular medicine for the treatment of gastrointestinal disorder, treatment of lesions, and also as anti-inflammatory microbicide. Citrobacter freundii is a member of the family Enterobacteriaceae and is one of the major causes of opportunistic infections. This microorganism is a bacterium (bacillus) aerobic gram-negative with a length in the range of 1 to 5 mm. C. freundii is commonly found in water, soil, food and occasionally in the gastrointestinal tract of animals and humans. In this paper, we have demonstrated the antibacterial activity of S. barbatiman by observing cellular death by using inhibition halo approach. Atomic force microscopy and FT-IR spectroscopy results suggested that interaction between the main active components of S. barbatiman with cellular wall of C. freundii gives rise to cellular wall damage, and then leads this microorganism to death.展开更多
基金supported by the project (grant 2005CB522904 and 2005CB522905) from the Ministry of Scientific Technologythe project (grant 2008ZX10004-001, 2008ZX10004-008, and 2009ZX10004-101) from the Ministry of Scientific Technology and the Ministry of Health of the People’s Republic of China
文摘Objective To establish and compare the pulsed-field gel electrophoresis (PFGE), multiple-locus variable number tandem repeat analysis (MLVA) and automated ribotyping for subtyping of Citrobacter strains. Methods PFGE protocol was optimized in terms of plug preparation procedure, restriction enzymes and configuration of electrophoretic parameters. MLVA method was evaluated by finding variable number tandem repeats in two genomes of Citrobacter strains. The ribotyping was performed by using the automated RiboPrinter system. Results We optimized the plug preparation procedure, focused on the cell suspension concentration (turbidity of 2.5 to 3.5), SDS addition (no SDS needed) and lysis time (1 h), and selected the appropriate restriction enzyme (XbaI) and the electrophoretic parameters (1.0 s-20.0 s for 19 h) of PFGE. There was nearly no discriminatory power of MLVA between Citrobacter strains. For 51 Citrobacter strains, automated ribotyping gave a D-value of 0.9945, while PFGE gave a D-value of 0.9969. Both PFGE and automated ribotyping clustered strains from the same sources (with the same species from the same place at the same time identified as the same source) and divided strains from different sources (from different years, places and hosts) into different subtypes. Conclusion PFGE protocol established in this paper and automated ribotyping are suitable for application in Citrobacter subtyping.
基金Supported by the Science and Technology Innovative Research Team of Anhui Academy of Agricultural Sciences(14C0504)the Youth Innovation Foundation of President of Anhui Academy of Agricultural Sciences(14B0529)Anhui Aquaculture Industry Technology System for Shrimp and Crab
文摘This experiment was conducted to clarify species and drug resistance of pathogen from the diseased Procambarus clarkia. Pathogenic bacteria from hepatopancreas of the diseased P. clarkia were examined using conventional methods,and then were isolated. The further tests and analysis of the isolated strain were developed,including the regression experiment to P. clarkia,the morphology,physiological and biochemical characteristics,sequence analysis of their 16 S rRNA and gyr B genes,and the susceptibility test to antibiotics. Large colonies with similar morphology and color were obtained. Strain X120523 was identified as Citrobacter freundii,proved to have strong pathogenicity,and was susceptible to quinolones and aminoglycosides.
文摘Pathogenic strains of E. coli including enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli (EHEC), enterotoxigenic E. coli (ETEC) are principle causes for diarrhoea in many parts of the globe. Citrobacter rodentium (C. rodentium), a gram negative bacterium, is a murine pathogen that also utilizes type III secretion system and similar virulence factors to EPEC and EHEC and forms comparable attaching/effacing lesions in the intestines as EPEC and EHEC. The infection caused by C. rodentium in mice is usually self-limiting and results in only minor systemic effects with higher mortality in some susceptible mouse strains. All these characteristics have made the bacteria a commonly used model to study host immune responses to pathogenic E. coli infection. In this review, we focus on the impact of virulence factors of the pathogen;different immune components involved in the immune response and summarize their role during C. rodentium infection.
文摘Rationale:Infectious keratopathy is an ocular emergency with the potential to cause irreversible blindness.Patient's concerns:A 63-year-old diabetic man presented with a 3-day history of painful red right eye.He had a history of multiple ocular surgeries in the affected eye without recent ocular trauma.Diagnosis:Infective crystalline keratopathy secondary to Citrobacter koseri.Interventions:Topical corticosteroids were discontinued,and dual topical antibiotic therapy of moxifloxacin 5%and gentamycin 0.3%were applied.Outcomes:Twelve hours after the start of treatment,the crystalline nature of the infiltrate disappeared,with enlargement of the epithelial defect.The antibiotic regime was continued and the lesion healed within a week of presentation with residual scarring.Lessons:Infective crystalline keratopathy classically presents with intrastromal branching fern-like opacities and minimal anterior segment inflammation in an immunosuppressed eye.The mainstay of management is corticosteroid discontinuation and the administration of empirical antibiotics until the results of the culture and sensitivity are available.In Citrobacter-related cases,treatment may result in a suppurative appearance before healing of the lesion.
基金This work was supported by CNPq and Capes (Brazil).
文摘Medicinal plants have been presented as a valuable source of preservation of human health. In special, Stryphnodendron barbatiman has been employed due to its antimicrobial activity. This plant is rich in tannins and has been used in popular medicine for the treatment of gastrointestinal disorder, treatment of lesions, and also as anti-inflammatory microbicide. Citrobacter freundii is a member of the family Enterobacteriaceae and is one of the major causes of opportunistic infections. This microorganism is a bacterium (bacillus) aerobic gram-negative with a length in the range of 1 to 5 mm. C. freundii is commonly found in water, soil, food and occasionally in the gastrointestinal tract of animals and humans. In this paper, we have demonstrated the antibacterial activity of S. barbatiman by observing cellular death by using inhibition halo approach. Atomic force microscopy and FT-IR spectroscopy results suggested that interaction between the main active components of S. barbatiman with cellular wall of C. freundii gives rise to cellular wall damage, and then leads this microorganism to death.
