Genetic Features of Plasmid- and Chromosome-Mediated mcr-1 in Escherichia coli Isolates From Animal Organs With Lesions
The genomic context of the mcr-1 gene in Escherichia coli from animal feces has been widely reported. However, less is known about the mcr-1 -carrying plasmid characteristics and other functional regions of Escherichia coli isolates from animal organs with lesions. The present study investigated the...
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Published in | Frontiers in microbiology Vol. 12 |
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Main Authors | , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Frontiers Media S.A
05.08.2021
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Subjects | |
Online Access | Get full text |
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Summary: | The genomic context of the
mcr-1
gene in
Escherichia coli
from animal feces has been widely reported. However, less is known about the
mcr-1
-carrying plasmid characteristics and other functional regions of
Escherichia coli
isolates from animal organs with lesions. The present study investigated the antimicrobial resistance, population structure, and genetic features of
mcr-1
-positive
Escherichia coli
strains isolated from animal organs with lesions. The antimicrobial susceptibility testing indicated that 24
mcr-1
-positive
Escherichia coli
isolates were resistant to at least three or all antimicrobial categories. MLST analysis suggested that the dominant clone complexes (CC) were mainly CC156, CC448, and CC10. In addition, ST10596, a newly discovered sequence type in swine, failed to be classified. Meanwhile, the
mcr-1
gene located on the different plasmids was successfully transferred to the recipients, and whole-genome sequencing indicated the
mcr-1
gene was embedded in
mcr-1-pap2
cassette but not flanked by IS
Apl1
. The
mcr-1
gene is located on the chromosome and embedded in Tn
6330
. Furthermore,
NDM-5
was found on the IncX3-type plasmid of J-8. The
virB6
and
traI
gene of type IV secretion system (T4SS) were truncated by IS
2
and IS
100
and located on the IncX4- and the IncHI2/HI2A/N-type plasmids, respectively. The multidrug-resistant (MDR) region of IncHI2/HI2A/N-type plasmids contained two class 1 integrons (In
0
, In
640
) and four composite transposons (Tn
4352
, Tn
6010
, cn_4692_IS
26
, cn_6354_IS
26
). Overall, 24
mcr-1
-positive
Escherichia coli
isolates in our study showed MDR, or even extensively drug resistant (XDR), and exhibited population diversity. The T4SS gene truncation by the insertion sequence may affect the efficiency of plasmid conjugative transfer. Furthermore, the class 1 integrons and composite transposons in the MDR region of IncHI2/HI2A/n-type plasmid contributed to the multireplicon plasmid formation, the acquisition, and transfer of antimicrobial resistance genes (ARGs). |
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Bibliography: | Reviewed by: João Pedro Rueda Furlan, University of São Paulo, Brazil; Ana Paula D’Alincourt Carvalho-Assef, Oswaldo Cruz Foundation (Fiocruz), Brazil Edited by: Prescilla Emy Nagao, Rio de Janeiro State University, Brazil These authors have contributed equally to this work This article was submitted to Antimicrobials, Resistance and Chemotherapy, a section of the journal Frontiers in Microbiology |
ISSN: | 1664-302X 1664-302X |
DOI: | 10.3389/fmicb.2021.707332 |