Carbapenem-and colistin-resistant Enterobacter has been a clinical and therapy problem in recent years.Here,we report the carbapenem-and colistin-resistant Enterobacter harboring bla_(IMI) isolated from intestinal sam...Carbapenem-and colistin-resistant Enterobacter has been a clinical and therapy problem in recent years.Here,we report the carbapenem-and colistin-resistant Enterobacter harboring bla_(IMI) isolated from intestinal samples and the environment of a duck farm in China.Four bla_(IMI)-positive Enterobacter isolates were resistant to carbapenem and colistin.Three bla_(IMI) subtypes were detected in different molecular categories of Enterobacter.The detection of the various IMI producers highlights the diversity of carbapenemases in a duck farm.Whole-genome sequencing demonstrated the bla_(IMI) genes were present in chromosomes or plasmids in these strains.The conjugation experiment demonstrated the ability of bla_(IMI)-carrying plasmid to transmit horizontally.The molecular evolution characteristics were examined through comparative genetic analysis.The study demonstrated the presence of chromosomal and plasmid bla_(IMI) and the bla_(IMI)-carrying plasmid exhibits a horizontal transmission between Enterobacter and Escherichia coli C600.The similar genetic content was discovered between two bla_(IMI-16)-positive Enterobacter asburiae.In addition,a bla_(IMI-16)-carrying plasmid is an IncFII(Yp)plasmid,and a substantial amount of mobile genetic elements were identified around bla_(IMI-16).The IS-like elements and IncFII(Yp)plasmid are significant in the propagation of bla_(IMI).Our study provides evidence for the transmission of diverse bla_(IMI) genes in China and supplies additional reference data for bla_(IMI)-positive antimicrobialresistant Enterobacter.Routine surveys of bla_(IMI)-positive Enterobacter from animal-raising environments must be given more focus.展开更多
To determine the occurrence of Enterobacter sakazakii and other Enerobateriaceae in commercial powdered infant formula (PIF), 185 packages of PIF from different manufacturers, supermarkets and drug-stores in Abidjan w...To determine the occurrence of Enterobacter sakazakii and other Enerobateriaceae in commercial powdered infant formula (PIF), 185 packages of PIF from different manufacturers, supermarkets and drug-stores in Abidjan were analyzed. Ten g of sample was homogenized in 90 ml of buffered peptone water (PBW, Biorad, Paris) for further studies. Enterobacteriaceae (coliforms) were enumerated according to French Association of Standardization methods. E. sakazakii was detected according to Kandhai’s method. Bacteria were identified using API20 system. Thirty-eight samples (20.5%) were positive for Enterobacteriaceae. Twenty-four samples (13%) yielded Enterobacter sakazakii. Other Enterobacteriaceae isolated included Pantoea spp. 21 (11.5%), Klebsiella pneumoniae subsp. Pneumonia 8 (4.3%), Citrobacter diversus 1 (0.5%), Citrobacter freundii 1 (0.5%), Enterobacter cloacae 1 (0.5%), Salmonella reading 1 (0.5%), Serratia ficara 1 (0.5%) Serratia odorifera 1 (0.5%). This study is the first report to describe the contamination of PIF from Abidjan with E. sakazakii and several other Enterobacteriaceae that could be opportunistic pathogens. Therefore, well-controlled studies need to be conducted to assess the extent of risk associated with contaminated PIF for infants in Abidjan.展开更多
Nucleoside phosphorylases (NPases) were found to be induced in Enterobacter aerogenes DGO-04, and cytidine and cytidine 5′-monophosphate (CMP) were the best inducers. Five mmol/L to fifteen mmol/L cytidine or CMP cou...Nucleoside phosphorylases (NPases) were found to be induced in Enterobacter aerogenes DGO-04, and cytidine and cytidine 5′-monophosphate (CMP) were the best inducers. Five mmol/L to fifteen mmol/L cytidine or CMP could distinctly increase the activities of purine nucleoside phosphorylase (PNPase), uridine phosphorylase (UPase) and thymidine phosphorylase (TPase) when they were added into medium from 0 to 8 h. In the process of enzymatic synthesis of adenine arabinoside from adenine and uracil arabinoside with wet cells of Enterobacter aerogenes DGO-04 induced by cytidine or CMP, the reaction time could be shortened from 36 to 6 h. After enzymatic reaction the activity of NPase in the cells induced remained higher than that in the cells uninduced.展开更多
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(32121004)。
文摘Carbapenem-and colistin-resistant Enterobacter has been a clinical and therapy problem in recent years.Here,we report the carbapenem-and colistin-resistant Enterobacter harboring bla_(IMI) isolated from intestinal samples and the environment of a duck farm in China.Four bla_(IMI)-positive Enterobacter isolates were resistant to carbapenem and colistin.Three bla_(IMI) subtypes were detected in different molecular categories of Enterobacter.The detection of the various IMI producers highlights the diversity of carbapenemases in a duck farm.Whole-genome sequencing demonstrated the bla_(IMI) genes were present in chromosomes or plasmids in these strains.The conjugation experiment demonstrated the ability of bla_(IMI)-carrying plasmid to transmit horizontally.The molecular evolution characteristics were examined through comparative genetic analysis.The study demonstrated the presence of chromosomal and plasmid bla_(IMI) and the bla_(IMI)-carrying plasmid exhibits a horizontal transmission between Enterobacter and Escherichia coli C600.The similar genetic content was discovered between two bla_(IMI-16)-positive Enterobacter asburiae.In addition,a bla_(IMI-16)-carrying plasmid is an IncFII(Yp)plasmid,and a substantial amount of mobile genetic elements were identified around bla_(IMI-16).The IS-like elements and IncFII(Yp)plasmid are significant in the propagation of bla_(IMI).Our study provides evidence for the transmission of diverse bla_(IMI) genes in China and supplies additional reference data for bla_(IMI)-positive antimicrobialresistant Enterobacter.Routine surveys of bla_(IMI)-positive Enterobacter from animal-raising environments must be given more focus.
文摘To determine the occurrence of Enterobacter sakazakii and other Enerobateriaceae in commercial powdered infant formula (PIF), 185 packages of PIF from different manufacturers, supermarkets and drug-stores in Abidjan were analyzed. Ten g of sample was homogenized in 90 ml of buffered peptone water (PBW, Biorad, Paris) for further studies. Enterobacteriaceae (coliforms) were enumerated according to French Association of Standardization methods. E. sakazakii was detected according to Kandhai’s method. Bacteria were identified using API20 system. Thirty-eight samples (20.5%) were positive for Enterobacteriaceae. Twenty-four samples (13%) yielded Enterobacter sakazakii. Other Enterobacteriaceae isolated included Pantoea spp. 21 (11.5%), Klebsiella pneumoniae subsp. Pneumonia 8 (4.3%), Citrobacter diversus 1 (0.5%), Citrobacter freundii 1 (0.5%), Enterobacter cloacae 1 (0.5%), Salmonella reading 1 (0.5%), Serratia ficara 1 (0.5%) Serratia odorifera 1 (0.5%). This study is the first report to describe the contamination of PIF from Abidjan with E. sakazakii and several other Enterobacteriaceae that could be opportunistic pathogens. Therefore, well-controlled studies need to be conducted to assess the extent of risk associated with contaminated PIF for infants in Abidjan.
基金Project (No. 07C26213101283) supported by the Innovation Fundfor Technology Based Firms from the Ministry of Science andTechnology of China
文摘Nucleoside phosphorylases (NPases) were found to be induced in Enterobacter aerogenes DGO-04, and cytidine and cytidine 5′-monophosphate (CMP) were the best inducers. Five mmol/L to fifteen mmol/L cytidine or CMP could distinctly increase the activities of purine nucleoside phosphorylase (PNPase), uridine phosphorylase (UPase) and thymidine phosphorylase (TPase) when they were added into medium from 0 to 8 h. In the process of enzymatic synthesis of adenine arabinoside from adenine and uracil arabinoside with wet cells of Enterobacter aerogenes DGO-04 induced by cytidine or CMP, the reaction time could be shortened from 36 to 6 h. After enzymatic reaction the activity of NPase in the cells induced remained higher than that in the cells uninduced.
