Emergence of concurrently transmissible mcr-9 and carbapenemase genes in bloodborne colistin-resistant Enterobacter cloacae complex isolated from ICU patients in Kolkata, India
Microbiology Spectrum,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 6, 2025
ABSTRACT
Colistin
resistance
in
carbapenem-resistant
Enterobacter
cloacae
complex
(CR-ECC)
infections
has
grown
expeditiously
but
detecting
the
underlying
mechanism
of
is
often
challenging
clinical
settings.
This
study,
first
its
kind
from
India,
determined
mechanisms
and
characterized
colistin-resistant
hospital
isolates.
Twenty-nine
bloodborne
CR-ECC
isolated
ICU
patients
eight
tertiary
care
hospitals
Kolkata,
India
between
2022
2023
were
screened
for
colistin
resistance.
The
plasmid-encoded
mcr
-9
gene,
acrAB-tolC
efflux
pump
(EP)
&
phoP/Q,
pmr
A/B
two-component
system
(TCS)
involved
examined.
In
addition,
AMR
gene
profiling
molecular
subtypes
-9-producing
isolates
also
investigated.
All
study
showed
to
≥5
antimicrobial
classes
six
(21%)
them
colistin-resistant.
transferable
by
IncHI2-HI2A
plasmid
was
detected
both
(67%)
colistin-sensitive
(4%)
bla
NDM-5
significantly
(
P
<
0.05)
associated
with
co-harboring
genes.
A
≥8-fold
increase
minimum
inhibitory
concentration
(MIC)
observed
strain
after
induction.
Overexpression
acrA,
ramA,
soxS
,
pmrA/B
genes
found
non-
wild-type
appeared
be
mediated
part
an
active
EP,
regulatory
TCS.
typed
into
ST932,
ST270,
ST1997
MLST.
Heterogeneity
(29
pulsotypes;
48.40%
similarity
coefficient)
among
circulating
revealed
PFGE.
Robust
monitoring
-sensitive
strains
warranted
curb
menace
nosocomial
pathogens.
IMPORTANCE
Carbapenem-resistant
become
a
global
pathogen
last
few
years.
Colistin,
“last
resort
antibiotic,”
being
widely
used
treatment
and,
consequently,
there
been
brisk
rise
necessitated
dearth
comprehensive
investigation
India.
notorious
plasmid-borne
mcr-9
along
phoP/Q-pmr
mediate
Interestingly,
discovered
MIC
under
pressure.
Diverse
phylogenetic
clones
novel
sequence
types
detected.
highlights
necessity
intense
conjunction
existing
epidemic
harboring
diverse
arrays
transmissible
Language: Английский
Study on collateral sensitivity of tigecycline to colistin-resistant Enterobacter cloacae complex
Kaixin Yu,
No information about this author
Jiming Wu,
No information about this author
Mingjing Liao
No information about this author
et al.
Microbiology Spectrum,
Journal Year:
2025,
Volume and Issue:
unknown
Published: May 23, 2025
ABSTRACT
The
past
decade
has
witnessed
the
emergence
and
spread
of
carbapenem-resistant
Enterobacter
cloacae
complex
(CRECC),
presenting
a
significant
clinical
challenge
urgently
demanding
new
treatment
strategies
against
antimicrobial
resistance
(AMR).
This
study
focused
on
impact
tigecycline
susceptibility
CRECC
isolates
to
colistin
collateral
sensitivity
in
CRECC.
Under
pressure,
five
clinically
isolated
strains
was
converted
from
sensitivity.
These
mutants
exhibited
significantly
higher
expression
acrA,
acrB
,
ramA
genes,
with
mutations
ramR
gene.
Overexpression
certain
did
not
alter
expression.
No
were
identified
lipid
A
synthesis
genes;
however,
phoQ
consistently
downregulated,
arnA
varied
among
CRECC405-resistant
mutants.
Low-dose
combination
therapy
outperformed
monotherapy
efficacy.
Overall,
observed
resistance.
overexpression
acrB,
due
mutations,
led
Inconsistent
levels
genes
affected
modification,
which
turn
upregulated
Increased
associated
downregulation
IMPORTANCE
Antimicrobial
(AMR)
is
escalating
faster
than
our
ability
manage
bacterial
infections,
antibiotic-resistant
bacteria
emerging
as
public
health
risk.
Innovative
are
needed
curb
AMR
dissemination.
Our
research
following
(TGC)
resistance,
resulting
newfound
(COL),
drug
it
once
resistant.
Synergistic
suppress
growth,
offering
promising
approach
combat
infections
progression
through
strategic
pairing
antibiotics
complementary
sensitivities.
Language: Английский