Genomic Characterization of VIM and MCR Co-Producers: The First Two Clinical Cases, in Italy
Vittoria Mattioni Marchetti,
Ibrahim Bitar,
Mario Sarti,
Elena Fogato,
Erika Scaltriti,
Chiara Bracchi,
Jaroslav Hrabak,
Stefano Pongolini,
Roberta Migliavacca
Affiliations
Vittoria Mattioni Marchetti
Department of Microbiology, Faculty of Medicine and University Hospital in Pilsen, Charles University, 306 05 Pilsen, Czech Republic
Ibrahim Bitar
Department of Microbiology, Faculty of Medicine and University Hospital in Pilsen, Charles University, 306 05 Pilsen, Czech Republic
Mario Sarti
Clinical Microbiology, Azienda Ospedaliero-Universitaria di Modena, 411 25 Modena, Italy
Elena Fogato
Laboratory of Clinical Microbiology, ASP “Golgi-Redaelli”, 201 46 Milan, Italy
Erika Scaltriti
Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia-Romagna, 43126 Parma, Italy
Chiara Bracchi
Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia-Romagna, 43126 Parma, Italy
Jaroslav Hrabak
Department of Microbiology, Faculty of Medicine and University Hospital in Pilsen, Charles University, 306 05 Pilsen, Czech Republic
Stefano Pongolini
Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia-Romagna, 43126 Parma, Italy
Roberta Migliavacca
Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, Unit of Microbiology and Clinical Microbiology, University of Pavia, 27100 Pavia, Italy
Background: the co-production of carbapenemases and mcr-genes represents a worrisome event in the treatment of Enterobacteriaceae infections. The aim of the study was to characterize the genomic features of two clinical Enterobacter cloacae complex (ECC) isolates, co-producing VIM and MCR enzymes, in Italy. Methods: species identification and antibiotic susceptibility profiling were performed using MALDI-TOF and broth microdilution methods, respectively. Transferability of the blaVIM- and mcr- type genes was verified through conjugation experiment. Extracted DNA was sequenced using long reads sequencing technology on the Sequel I platform (PacBio). Results: the first isolate showed clinical resistance against ertapenem yet was colistin susceptible (EUCAST 2020 breakpoints). The mcr-9.2 gene was harbored on a conjugative IncHI2 plasmid, while the blaVIM-1 determinant was harbored on a conjugative IncN plasmid. The second isolate, resistant to both carbapenems and colistin, harbored: mcr-9 gene and its two component regulatory genes for increased expression on the chromosome, mcr-4.3 on non-conjugative (yet co-transferable) ColE plasmid, and blaVIM-1 on a non-conjugative IncA plasmid. Conclusions: to our knowledge, this is the first report of co-production of VIM and MCR in ECC isolates in Italy.
