TY - JOUR
T1 - Genomic and molecular characterization of clinical isolates of Enterobacteriaceae harboring mcr-1 in Colombia, 2002 to 2016
AU - Saavedra, Sandra Yamile
AU - Diaz, Lorena
AU - Wiesner, Magdalena
AU - Correa, Adriana
AU - Alejandra Arévalo, Stefany
AU - Reyes, Jinnethe
AU - Hidalgo, Andrea Melissa
AU - De La Cadena, Elsa
AU - Perenguez, Marcela
AU - Montaño, Lucy Angeline
AU - Ardila, Javier
AU - Ríos, Rafael
AU - Ovalle, María Victoria
AU - Díaz, Paula
AU - Porras, Paola
AU - Villegas, Maria V.
AU - Arias, Cesar A.
AU - Beltrán, Mauricio
AU - Duarte, Carolina
N1 - Publisher Copyright:
© 2017 American Society for Microbiology. All Rights Reserved.
PY - 2017/12
Y1 - 2017/12
N2 - Polymyxins are last-resort antimicrobial agents used to treat infections caused by carbapenem-resistant Enterobacteriaceae. Due to the worldwide dissemination of polymyxin resistance in animal and human isolates, we aimed to characterize polymyxin resistance associated with the presence of mcr-1 in Enterobacteriaceae and nonfermenter Gram-negative bacilli, using isolates collected retrospectively in Colombia from 2002 to 2016. A total of 5,887 Gram-negative clinical isolates were studied, and 513 were found to be resistant to the polymyxins. Susceptibility to colistin was confirmed by broth microdilution for all mcr-1-positive isolates, and these were further subjected to whole-genome sequencing (WGS). The localization of mcr-1 was confirmed by S1 pulsed-field gel electrophoresis (S1-PFGE) and CeuI-PFGE hybridization. Transferability was evaluated by mating assays. A total of 12 colistin-resistant isolates recovered after 2013 harbored mcr-1, including 8 Escherichia coli, 3 Salmonella enterica serovar Typhimurium, and 1 Klebsiella pneumoniae isolate. E. coli isolates were unrelated by PFGE and belonged to 7 different sequence types (STs) and phylogroups. S. Typhimurium and K. pneumoniae isolates belonged to ST34 and ST307, respectively. The mcr-1 gene was plasmid borne in all isolates but two E. coli isolates which harbored it on the chromosome. Conjugation of mcr-1 was successful in 8 of 10 isolates (8.2 105 to 2.07 101 cell per recipient). Plasmid sequences showed that the mcr-1 plasmids belonged to four different Inc groups (a new IncP-1 variant and the IncFII, IncHI1, and IncH families). Our results indicate that mcr-1 is circulating in clinical isolates of colistin-resistant Enterobacteriaceae in Colombia and is mainly harbored in transferable plasmids.
AB - Polymyxins are last-resort antimicrobial agents used to treat infections caused by carbapenem-resistant Enterobacteriaceae. Due to the worldwide dissemination of polymyxin resistance in animal and human isolates, we aimed to characterize polymyxin resistance associated with the presence of mcr-1 in Enterobacteriaceae and nonfermenter Gram-negative bacilli, using isolates collected retrospectively in Colombia from 2002 to 2016. A total of 5,887 Gram-negative clinical isolates were studied, and 513 were found to be resistant to the polymyxins. Susceptibility to colistin was confirmed by broth microdilution for all mcr-1-positive isolates, and these were further subjected to whole-genome sequencing (WGS). The localization of mcr-1 was confirmed by S1 pulsed-field gel electrophoresis (S1-PFGE) and CeuI-PFGE hybridization. Transferability was evaluated by mating assays. A total of 12 colistin-resistant isolates recovered after 2013 harbored mcr-1, including 8 Escherichia coli, 3 Salmonella enterica serovar Typhimurium, and 1 Klebsiella pneumoniae isolate. E. coli isolates were unrelated by PFGE and belonged to 7 different sequence types (STs) and phylogroups. S. Typhimurium and K. pneumoniae isolates belonged to ST34 and ST307, respectively. The mcr-1 gene was plasmid borne in all isolates but two E. coli isolates which harbored it on the chromosome. Conjugation of mcr-1 was successful in 8 of 10 isolates (8.2 105 to 2.07 101 cell per recipient). Plasmid sequences showed that the mcr-1 plasmids belonged to four different Inc groups (a new IncP-1 variant and the IncFII, IncHI1, and IncH families). Our results indicate that mcr-1 is circulating in clinical isolates of colistin-resistant Enterobacteriaceae in Colombia and is mainly harbored in transferable plasmids.
KW - Colombia
KW - Enterobacteriaceae
KW - Genomic
KW - mcr-1
UR - https://www.scopus.com/pages/publications/85034961923
U2 - 10.1128/AAC.00841-17
DO - 10.1128/AAC.00841-17
M3 - Article
C2 - 28893788
AN - SCOPUS:85034961923
SN - 0066-4804
VL - 61
JO - Antimicrobial Agents and Chemotherapy
JF - Antimicrobial Agents and Chemotherapy
IS - 12
M1 - e00841
ER -
