Corrigendum: Genetic and Phenotypic Characterization of the Novel Metallo-β-Lactamase NDM-29 From Escherichia coli

Objectives: The New Delhi metallo-β-lactamase (NDM) can hydrolyze almost all clinically available β-lactam antibiotics and has widely spread all over the world. NDM-29, a novel carbapenemase, was discovered in an Escherichia coli (19NC225) isolated from a patient with biliary tract infection in 2019 in China.Methods: Conjugation, transformation, cloning test, fitness cost, PacBio Sequel, and Illumina sequencing were performed to analyze the genetic and phenotypic characterization of blaNDM–29.Results: The susceptibility testing results showed 19NC225 was resistant to cephalosporins, carbapenems, combinations of β-lactam and β-lactamase inhibitors, and levofloxacin. Conjugation and transformation were performed to verify the transferability of NDM-29-encoding plasmid, and cloning test was conducted to prove the function of blaNDM–29 to increase carbapenem resistance. Furthermore, fitness cost test confirmed that the presence of NDM-29 exerts no survival pressure on bacteria. PacBio Sequel and Illumina sequencing were performed to analyze the genetic characterization of 19NC225, which contains two plasmids (pNC225-TEM1B and pNC225-NDM-29). pNC225-NDM-29, exhibiting 99.96% identity and 100% coverage with pNDM-BTR (an IncN1 plasmid from an E. coli in urine specimen from Beijing in 2013), showed responsibility for the multidrug-resistant (MDR) phenotype. Compared with blaNDM–1, blaNDM–29, located on pNC225-NDM-29, carries a G388A (D130N) mutation. The region harboring blaNDM–29 is located in an ISKpn19-based transposon, and two Tn6292 remnants are symmetrically located upstream and downstream of the transposon. The sequence results also indicated several important virulence genes.Conclusion: The findings of the novel carbapenemase NDM-29 could pose a threat to the control of antimicrobial resistance and arouse attention about the mutation of bacteria.

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Phenotypic Characterization of Escherichia coli Isolated from Broiler Chiken

Suez Canal Veterinary Medicine Journal. SCVMJ ◽

10.21608/scvmj.2019.57368 ◽

2019 ◽

Vol 24 (1) ◽

pp. 1-12

Keyword(s):

Escherichia Coli ◽

Phenotypic Characterization

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Characterization of novel ybjG and dacC variants in Escherichia coli

Journal of Medical Microbiology ◽

10.1099/jmm.0.062893-0 ◽

2013 ◽

Vol 62 (11) ◽

pp. 1728-1734 ◽

Cited By ~ 4

Author(s):

Dongguo Wang ◽

Enping Hu ◽

Jiayu Chen ◽

Xiulin Tao ◽

Katelyn Gutierrez ◽

...

Keyword(s):

Escherichia Coli ◽

Multiple Drug Resistance ◽

Multiple Drug ◽

The Novel ◽

Conventional Pcr ◽

E Coli ◽

Novel Variants ◽

Restriction Sites ◽

Genetic Structures

A total of 69 strains of Escherichia coli from patients in the Taizhou Municipal Hospital, China, were isolated, and 11 strains were identified that were resistant to bacitracin, chloramphenicol, tetracycline and erythromycin. These strains were PCR positive for at least two out of three genes, ybjG, dacC and mdfA, by gene mapping with conventional PCR detection. Conjugation experiments demonstrated that these genes existed in plasmids that conferred resistance. Novel ybjG and dacC variants were isolated from E. coli strains EC2163 and EC2347, which were obtained from the sputum of intensive care unit patients. Genetic mapping showed that the genes were located on 8200 kb plasmid regions flanked by EcoRI restriction sites. Three distinct genetic structures were identified among the 11 PCR-positive strains of E. coli, and two contained the novel ybjG and dacC variants. The putative amino acid differences in the ybjG and dacC gene variants were characterized. These results provide evidence for novel variants of ybjG and dacC, and suggest that multiple drug resistance in hospital strains of E. coli depends on the synergistic function of ybjG, dacC and mdfA within three distinct genetic structures in conjugative plasmids.

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