AUTHOR=Cañada-García Javier E. , Grippo Natalin , de Arellano Eva Ramírez , Bautista Verónica , Lara Noelia , Navarro Ana María , Cabezas Teresa , Martínez-Ramírez Nora Mariela , García-Cobos Silvia , Calvo Jorge , Cercenado Emilia , Aracil Belén , Pérez-Vázquez María , Oteo-Iglesias Jesús ,  the Spanish IMP Study Group 

TITLE=Phenotypic and molecular characterization of IMP-producing Enterobacterales in Spain: Predominance of IMP-8 in Klebsiella pneumoniae and IMP-22 in Enterobacter roggenkampii

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.1000787

DOI=10.3389/fmicb.2022.1000787

ISSN=1664-302X

ABSTRACT=<sec><title>Objectives</title><p>Little is known about IMP-producing Enterobacterales (IMP-Ent) in Europe. We analyzed at genomic and phenotypic level IMP-Ent isolates circulating in Spain in a 9-year period.</p></sec><sec><title>Materials and methods</title><p>IMP-Ent isolates submitted to our reference laboratory were included. Antibiotic susceptibility was performed using microdilution method (EUCAST), and IMP-carbapenemase activity was measured with carbapenemase inhibitors, the β-CARBA method, the modified Hodge test (MHT), and the modified carbapenemase inhibition method (mCIM). All isolates collected were sequenced for high-resolution single-nucleotide polymorphism (SNP) typing, core genome multilocus sequence typing (cgMLST), and resistome analysis.</p></sec><sec><title>Results</title><p>Fifty IMP-Ent isolates, collected from 19 hospitals in 13 Spanish provinces, were detected: <italic>Klebsiella pneumoniae</italic> (IMP-Kpn) (24; 48%), <italic>Enterobacter roggenkampii</italic> (13; 26%), <italic>Enterobacter hormaechei</italic> (8, 16%), <italic>Klebsiella oxytoca</italic> (two; 4%), <italic>Enterobacter asburiae</italic> (one, 2%), <italic>Serratia marcescens</italic> (one; 2%) and <italic>Escherichia coli</italic> (one; 2%). All isolates were positive by the MHT and β-CARBA tests; 48 (96%) were mCIM positive; 12 (24%) and 26 (52%) displayed positive inhibition with dipicolinic (meropenem) and EDTA (ertapenem), respectively. Five IMP-carbapenemase types were identified: IMP-8 (22; 44%), IMP-22 (17; 34%), IMP-13 (7; 14%), IMP-28 (two; 4%), and IMP-15 (two; 4%), predominating IMP-8 in <italic>K. pneumoniae</italic> and IMP-22 in <italic>E. roggenkampii</italic>. IMP-28 was exclusively identified in <italic>K. oxytoca</italic> and IMP-15 in <italic>E. hormaechei</italic>. Predominant STs were ST405 (29.2%), ST15 (25%) and ST464 (20.8%) in IMP-Kpn; ST96 (100%) in <italic>E. roggenkampii</italic> and ST182 (62.5%) in <italic>E. hormachei</italic>. Colistin and amikacin were the most active non-carbapenem antibiotics against IMP-Ent.</p></sec><sec><title>Conclusion</title><p>IMP-Ent isolates remain infrequent in Spain, although in recent years have been circulating causing nosocomial outbreaks, being IMP-8-producing <italic>K. pneumoniae</italic> and IMP-22-producing <italic>E. roggenkampii</italic> the most frequently detected in this study. Inhibition with EDTA or dipicolinic acid presented false negative results in some IMP-producing strains. Active microbiological and molecular surveillance is essential for a better comprehension and control of IMP-Ent dissemination.</p></sec>