| Abstract
The emergence of Klebsiella pneumoniae
carbapenemase (KPC) resistance has
led to the countdown of activity of carbapenems,
which were considered as drugs of last
resort for infections caused by
Enterobacteriaceae. The aims of the present
study were the detection of KPC-production
among K. pneumoniae isolates, select the
appropriate method for its detection and
assess the consequence of KPC production
on the antibiotics susceptibility. One hundred
and four non-duplicated K. pneumoniae isolates
were collected from University teaching
hospitals of Tabriz, Iran. The disk diffusion,
E-test, and Modified Hodge test were
performed for the determination of antibiotic
susceptibility pattern, Minimum Inhibitory
Concentrations (MICs) determination and
the production of carbapenemase, respectively.
BlaKPC-2 gene was detected by using
PCR. High levels of resistance were
observed towards co-trimoxazole (69.2%),
followed by cefazolin (66.3%), ceftriaxone
(65.4%), ofloxacin and ciprofloxacin
(54.8%), gentamicin (50%), and amikacin
(39.4%). According to the disk diffusion
method, the frequency of imipenem and
meropenem resistance was 31.7% and
32.7%, respectively. Colistin was the most
effective antibiotic among panels of antibiotics
tested. Imipenem MICs range, MIC50
and MIC90 were 0.19-32 μg/ml, 4μg/ml, and
16μg/ml, respectively. Modified Hodge test
was positive in 24 (63.2%) isolate however,blaKPC-2 gene was detected in 8 (21.1%) carbapenem-
resistant isolates. Results of the
present study revealed a high rate of carbapenem-
resistance in K. pneumoniae by
phenotypic method, however the presence of
one of the molecular, namely blaKPC-2 was not
found as predominant cause. Therefore, their
reliable detection should be the first priority
to combat the infections. Being a simple test,
the imipenem disk diffusion could be considered
as an appropriate method for the detection
of carbapenem-resistant isolates in the
routine diagnosis.
Key words: Klebsiella pneumoniae; BlaKPC2;
Carbapenemase; Modified Hodge test. |