(Open access funding provided by Semmelweis University)
OTKA(108481)
Background: This study was carried out to determine the prevalence and the genetic
background of extended-spectrum beta-lactamase-producing Escherichia coli invasive
isolates obtained from a tertiary-care hospital in Budapest, Hungary. Methods: Between
October-November 2018, all invasive ESBL-producing E. coli isolates were collected
from Central Hospital of Southern Pest. The antimicrobial susceptibility testing was
performed according to the EUCAST guidelines. The possible clonal relationships were
investigated by core genome (cg)MLST (SeqSphere +) using whole-genome sequencing (WGS)
data of isolates obtained from Illumina 251-bp paired-end sequencing. From WGS data
acquired antimicrobial resistance genes, virulence genes and replicon types were retrieved
using ResFinder3.1, PlasmidFinder2.1, pMLST-2.0, VirulenceFinder2.0 and Virulence
Factors Database online tools. Results: Overall, six E. coli isolates proved to be
resistant to third-generation cephalosporins and ESBL-producers in the study period.
Full genome sequence analysis showed that five E. coli isolates belonged to the ST131
clone: two to C1-M27 subclade with bla(CTX-M-27) and three to C2/H30Rx subclade with
bla(CTX-M-15). One isolate belonged to ST1193 with bla(CTX-M-27). According to cgMLST,
all C2/H30Rx isolates formed a cluster (<= 6 allele differences), while the bla(CTX-M-27)-producing
C1-M27 isolates differed at least 35 alleles from each other. Both C2/H30Rx and C1-M27
ST131 isolates harbored similar antimicrobial resistance gene sets. However, only
C2/H30Rx isolates had the qnrB and aac(3)-IIa. The isolates carried similar extraintestinal
virulence gene set but differed in some genes encoding siderophores, protectins and
toxins. Moreover, only one C2/H30Rx isolate carried salmochelin siderophore system
and showed virotype B. All isolates showed resistance against ceftriaxone, cefotaxime,
and ciprofloxacin, and the C2/H30Rx isolates were also resistant to gentamicin, tobramycin,
and ceftazidime. Conclusions: Out of six ESBL-producing E. coli, five belonged to
the ST131 clone. This study indicates, that the C2/H30Rx and C1-M27 subclades of the
ST131 appear to be the dominant clones collected in a Hungarian hospital.
