Identification of mcr-8 in Clinical Isolates From Qatar and Evaluation of Their Antimicrobial Profiles

• Published in: Frontiers in microbiology Vol. 11; p. 1954
• Main Authors: Eltai, Nahla O., Kelly, Brianna, Al-Mana, Hassan A., Ibrahim, Emad B., Yassine, Hadi M., Al Thani, Asmaa, Al Maslmani, Muna, Lammens, Christine, Xavier, Basil B., Malhotra-Kumar, Surbhi
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 24-08-2020
• Subjects: colistin; E. coli; K. pneumoniae; mcr-1.1; mcr-8.1; Microbiology; Qatar
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2020.01954

This study was performed to investigate the genotypic causes of colistin resistance in 18 colistin-resistant
Klebsiella pneumoniae
(
n
= 13),
Escherichia coli
(
n
= 3) and
Pseudomonas aeruginosa
(
n
= 2) isolates from patients at the Hamad General Hospital, Qatar. MIC testing for colistin was performed using Phoenix (BD Biosciences, Heidelberg, Germany) and then verified with SensiTest Colistin (Liofilchem, Zona Ind. le, Italy). Strains determined to be resistant (MIC > 4-16 μg/mL) were then whole-genome sequenced (MiSeq, Illumina, Inc.). Sequences were processed and analysed using BacPipe v1.2.6, a bacterial whole genome sequencing analysis pipeline. Known chromosomal modifications were determined using CLC Genomics Workbench v.9.5.3 (CLCbio, Denmark). Two
K. pneumoniae
isolates (KPN-15 and KPN-19) harboured
mcr-8.1
on the IncFII(K) plasmids, pqKPN-15 and pqKPN-19, and belonged to ST383 and ST716, respectively. One
E. coli
isolate harboured
mcr-1.1
on the
IncI2
plasmid pEC-12. The other 15 isolates harboured known chromosomal mutations linked to colistin resistance in the PhoPQ two-component system. Also, three
K. pneumoniae
strains (KPN-9, KPN-10 and KPN-15) showed disruptions due to IS elements in
mgrB
. To our knowledge, this marks the first description of
mcr-8.1
in
K. pneumoniae
of human origin in Qatar. Currently, more research is necessary to trace the source of
mcr-8.1
and its variants in humans in this region.