1.Emerging and comparative genomic analysis of a novel plasmid carrying blaKPC-2 in Citrobacter freundii.
Hui Qian GUO ; Xin Yue LI ; Su Ming CHEN ; Wang ZHANG ; Chun Mei BAO ; Zhe YIN ; Bo An LI
Chinese Journal of Preventive Medicine 2023;57(12):2122-2128
Objective: To explore the drug resistance mechanism and gene structure characteristics of a carbapenemase-producing novel incompatibility group plasmid pNY2385-KPC from Citrobacter freundii. Methods: A multi-drug resistant strain was obtained from urine samples of patients with fever in the emergency ward of Li Huili Hospital, Ningbo Medical Center. Bacterial species was preliminary identified and finally confirmed by 16S rRNA gene amplification and the average nucleotide identity alignment, respectively. The minimum inhibitory concentrations of the antimicrobial agents were determined by VITEK 2 Compact System. The complete genome sequence was obtained by "third-generation" sequencing methods, and then detailed annotation of gene function and comparative genomic analysis of plasmid structure were carried out by BLASTP/BLASTN, RefSeq, ConservedDomains, ResFinder, Isfinder, etc. Results: The pNY2385-KPC carried by citrobacter freundii NY2385 belonged a novel incompatibility group, and contained blaKPC-2 and conjugative transfer (type Ⅳ secretory system, T4SS) genes, which could induce conjugative transfer. A total of 15 plasmids of the same type as pNY2385-KPC were retrieved by NCBI, which were from Citrobacter freundii, and the rest were from Serratia marcescens, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Raoultella planticola and other bacteria, and were broad-host-range plasmids. The sequence comparative analysis of all 6 of the novel plasmid from Citrobacter freundii showed that the structure of the novel plasmid had certain conserved property, with Tn6296 variant structure carrying blaKPC-2, and plasmid pCF1807-3 had both repApNY2385-KPC and repAIncX8. Conclusion: The pNY2385-KPC type plasmids in Citrobacter freundii carried blaKPC-2 resistance gene, which were divided into two subtypes: repApNY2385-KPC single replicator and repApNY2385-KPC/repAIncX8 complex replicator, belonging to broad-host-range plasmids. And as a mobile genetic element, the plasmids promote the spread of blaKPC-2.
Humans
;
Citrobacter freundii/genetics*
;
RNA, Ribosomal, 16S/genetics*
;
Emergency Service, Hospital
;
Escherichia coli
;
Genomics
2.Emerging and comparative genomic analysis of a novel plasmid carrying blaKPC-2 in Citrobacter freundii.
Hui Qian GUO ; Xin Yue LI ; Su Ming CHEN ; Wang ZHANG ; Chun Mei BAO ; Zhe YIN ; Bo An LI
Chinese Journal of Preventive Medicine 2023;57(12):2122-2128
Objective: To explore the drug resistance mechanism and gene structure characteristics of a carbapenemase-producing novel incompatibility group plasmid pNY2385-KPC from Citrobacter freundii. Methods: A multi-drug resistant strain was obtained from urine samples of patients with fever in the emergency ward of Li Huili Hospital, Ningbo Medical Center. Bacterial species was preliminary identified and finally confirmed by 16S rRNA gene amplification and the average nucleotide identity alignment, respectively. The minimum inhibitory concentrations of the antimicrobial agents were determined by VITEK 2 Compact System. The complete genome sequence was obtained by "third-generation" sequencing methods, and then detailed annotation of gene function and comparative genomic analysis of plasmid structure were carried out by BLASTP/BLASTN, RefSeq, ConservedDomains, ResFinder, Isfinder, etc. Results: The pNY2385-KPC carried by citrobacter freundii NY2385 belonged a novel incompatibility group, and contained blaKPC-2 and conjugative transfer (type Ⅳ secretory system, T4SS) genes, which could induce conjugative transfer. A total of 15 plasmids of the same type as pNY2385-KPC were retrieved by NCBI, which were from Citrobacter freundii, and the rest were from Serratia marcescens, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Raoultella planticola and other bacteria, and were broad-host-range plasmids. The sequence comparative analysis of all 6 of the novel plasmid from Citrobacter freundii showed that the structure of the novel plasmid had certain conserved property, with Tn6296 variant structure carrying blaKPC-2, and plasmid pCF1807-3 had both repApNY2385-KPC and repAIncX8. Conclusion: The pNY2385-KPC type plasmids in Citrobacter freundii carried blaKPC-2 resistance gene, which were divided into two subtypes: repApNY2385-KPC single replicator and repApNY2385-KPC/repAIncX8 complex replicator, belonging to broad-host-range plasmids. And as a mobile genetic element, the plasmids promote the spread of blaKPC-2.
Humans
;
Citrobacter freundii/genetics*
;
RNA, Ribosomal, 16S/genetics*
;
Emergency Service, Hospital
;
Escherichia coli
;
Genomics
3.Construction of novel recombinant strain harboring glycerol dehydratase reactivating factor capable of producing 1,3-propanediol.
Chinese Journal of Biotechnology 2007;23(5):841-845
The dhaB gene encoding glycerol dehydratase and dhaG dhaF gene encoding glycerol dehydratase reactivating factor from Citrobacterfreundii were amplified by PCR. The temperature control expression vector pHsh harboring yqhD, dhaB, dhaG and dhaF gene was transformed into E. coli JM109 to yield the recombinant strain E. coli JM109 (pHsh-dhaB-dhaG-dhaF-yqhD). The results from SDS-PAGE analysis show that the recombinant product was consistent with the molecular weight predicted from gene sequence. The fermentation result show that the yield of 1,3-propanediol was increased by 28% compared with E. coli JM109(pHsh-dhaB-yqhD).
Bacterial Proteins
;
biosynthesis
;
genetics
;
Citrobacter freundii
;
genetics
;
metabolism
;
Escherichia coli
;
genetics
;
metabolism
;
Hydro-Lyases
;
biosynthesis
;
genetics
;
Propylene Glycols
;
metabolism
;
Transformation, Bacterial
;
genetics
4.Identification of ACT-1 Plasmid-Mediated AmpC beta-Lactamase Producing Citrobacter freundii from a Chinese Patient.
Annals of Laboratory Medicine 2013;33(1):86-88
No abstract available.
Aged
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Anti-Bacterial Agents/pharmacology/therapeutic use
;
Asian Continental Ancestry Group
;
Bacterial Proteins/genetics/*metabolism
;
China
;
Cilastatin/therapeutic use
;
Citrobacter freundii/drug effects/*enzymology/isolation & purification
;
Drug Combinations
;
Drug Resistance, Multiple, Bacterial
;
Humans
;
Imipenem/therapeutic use
;
Male
;
Microbial Sensitivity Tests
;
Plasmids/*metabolism
;
Respiratory Tract Infections/*diagnosis/drug therapy/microbiology
;
beta-Lactamases/genetics/*metabolism