Affiliation:
1. Division of Infectious Diseases, Department of Internal Medicine, Taichung Veterans General Hospital , Taichung, Taiwan
2. Center for Diagnostics and Vaccine Development, Centers for Disease Control , Taichung, Taiwan
Abstract
ABSTRACT
We report that carbapenem resistance developed in an extensively drug-resistant
Salmonella enterica
serovar Agona strain during antimicrobial therapy and in an AmpC β-lactamase-producing
S
. Infantis strain. Whole-genome sequence analysis indicated that carbapenem resistance in the
S
. Agona strain was associated with the insertion of a 160-kb IS15DI composite transposon in
ompC_378
, which encodes a porin consisting of 378 amino acids, along with a 397-bp deletion in the
ompD
. The transposon harbored 12 resistance genes including
bla
CTX-M-55
and an efflux pump regulatory gene,
ramAp
. Carbapenem resistance in the
bla
CMY-2
-carrying
S
. Infantis strain was linked to the insertion of a 22,905-bp segment located 10 bp upstream of the
ompC_378
coding sequence, as well as a 254-bp deletion in
ompD
. Our findings indicate that the loss of both
ompC_378
and
ompD
is necessary for carbapenem resistance in extended-spectrum β-lactamase and AmpC β-lactamase-producing
Salmonella
strains.
IMPORTANCE
Carbapenem resistance arising from the loss of porins is commonly observed in extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase-producing strains of certain
Enterobacteriaceae
genera, including
Klebsiella pneumoniae
,
Escherichia coli
, and
Pseudomonas aeruginosa
. However, this resistance mechanism is rarely reported in the
Salmonella
genus. To address this knowledge gap, our study offers genetic evidence demonstrating that the loss of two specific porins (OmpC_378 and OmpD) is crucial for the development of carbapenem resistance in
Salmonella
ESBL and AmpC β-lactamase-producing strains. Furthermore, our findings reveal that most
Salmonella
serovars carry seven porin parathologs, with OmpC_378 and OmpD being the key porins involved in the development of carbapenem resistance in
Salmonella
strains.
Funder
Ministry of Health and Welfare
Taichung Veterans General Hospital
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Cell Biology,Microbiology (medical),Genetics,General Immunology and Microbiology,Ecology,Physiology