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Genomic Insights into Colistin-Resistant Klebsiella pneumoniae from a Tunisian Teaching Hospital
The emergence of colistin-resistant (CoR ) is a public health concern, since this antibiotic has become the last line of treatment for infections caused by multidrug-resistant (MDR) Gram negatives. In this study, we have investigated the molecular basis of colistin resistance in 13 MDR strains isola...
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Published in: | Antimicrobial agents and chemotherapy 2018-02, Vol.62 (2) |
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Main Authors: | , , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | The emergence of colistin-resistant
(CoR
) is a public health concern, since this antibiotic has become the last line of treatment for infections caused by multidrug-resistant (MDR) Gram negatives. In this study, we have investigated the molecular basis of colistin resistance in 13 MDR
strains isolated from 12 patients in a teaching hospital in Sousse, Tunisia. Whole-genome sequencing (WGS) was used to decipher the molecular mechanism of colistin resistance and to identify the resistome of these CoR
isolates. It revealed a genome of ca. 5.5 Mbp in size with a G+C content of 57%, corresponding to that commonly observed for
These isolates belonged to the 5 different sequence types (ST11, ST15, ST101, ST147, and ST392), and their resistome was composed of acquired β-lactamases, including extended-spectrum beta-lactamase and carbapenemase genes (
,
,
, and
genes), aminoglycoside resistance genes [
(
')
,
(
″)-
,
(
)-
, and
(
)-
], and fosfomycin (
), fluoroquinolone (
-like), chloramphenicol, trimethoprim, and tetracycline resistance genes. All of the isolates were identified as having a mutated
gene. Mapping reads with reference sequences of the most common genes involved in colistin resistance revealed several modifications in
,
, and
operons (deletions, insertions, and substitutions) likely affecting the function of these proteins. It is worth noting that among the 12 patients, 10 were treated with colistin before the isolation of CoR
No plasmid encoding
to
genes was found in these isolates. This study corresponds to the first molecular characterization of a collection of CoR
strains in Tunisia and highlights that the small-transmembrane protein MgrB is a main mechanism for colistin resistance in
. |
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ISSN: | 0066-4804 1098-6596 |
DOI: | 10.1128/AAC.01601-17 |