Objectives: The spread of carbapenem-resistant Enterobacteriaceae (CRE) represents one of the most worrisome problems for clinical medicine worldwide. In Italy, the Antibiotic-Resistance-Istituto Superiore di Sanità surveillance network, in collaboration with the Committee for Antimicrobial Agents of the Italian Society of Clinical Microbiologists, promoted a study to investigate the carbapenem-resistance mechanisms, clonal relatedness and capsular typing of a recent collection of carbapenem-resistant Klebsiella pneumoniae (CR-KP). Methods: A total of 17 laboratories distributed across Italy collected all consecutive non-replicate CR-KP isolated from invasive infections during two different study periods (2011-12 and 2013). Carbapenemase genes were searched for by filter hybridization and confirmed by PCR and sequencing. KPC-producing K. pneumoniae (KPC-KP) were typed by PFGE and MLST. Capsular types were identified by wzi gene typing. Results: Of the collected K. pneumoniae isolates (n=461), the overall proportion of CR-KP was 36.2% (n=167). The majority (97%) of the CR-KP were positive for the blaKPC gene. Among the KPC-KP population, nine different STs were detected with the majority of isolates (94%) belonging to the clonal group (CG) 258. A subpopulation that belonged to ST512 and showed an identical PFGE profile represented the majority (57%) of KPC-KP strains, with a countrywide distribution. Capsular characterization showed the predominance of the wzi154, cps-2 capsular type (88.8% of all CG258 strains). ST258 strains were associated with both cps-1 and cps-2 capsular types, while ST512 was associated with cps-2 only. Conclusions: Although a trend to a polyclonal evolution of the Italian KPC-KP was noted, this study showed that the KPC-KP population remained largely oligoclonal with the wide diffusion of an ST512 lineage carrying cps-2 capsular type and producing the KPC-3 enzyme.

Molecular epidemiology of KPC-producing Klebsiella pneumoniae from invasive infections in Italy. Increasing diversity with predominance of the ST512 clade II sublineage / Conte, V.; Monaco, M.; Giani, T.; D'Ancona, F.; Moro, M. L.; Arena, F.; D'Andrea, M. M.; Rossolini, G. M.; Pantosti, A.; Bianchi, E.; Catania, M. R.; Cavalcanti, P.; De Nittis, R.; Dusi, P. A.; Grandesso, S.; Gualdi, P.; Imbriani, A.; Pini, B.; Vincenzi, C.; Meledandri, M.; Agrappi, C.; Parisi, G.; Pollini, S.; Restelli, A.; Rocchetti, A.; Vailati, F.; Aschbacher, R.; Barbaro, A.; Bona, R.; Chirillo, M.; Corradini, S.; Cuccurullo, S.; De Bernochi, A.; Dodi, C.; Giammanco, A.; Mencacci, A.; Milano, F.; Miragliotta, G.; Mungiguerra, M.; Pedna, M. F.; Piana, F.; Porcheddu, G. M.; Rossi, M. R.; Santino, I.; Sartor, A.; Sartore, P.. - In: JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY. - ISSN 0305-7453. - 71:12(2016), pp. 3386-3391. [10.1093/jac/dkw337]

Molecular epidemiology of KPC-producing Klebsiella pneumoniae from invasive infections in Italy. Increasing diversity with predominance of the ST512 clade II sublineage

D'Ancona F.;Catania M. R.;Cavalcanti P.;Rocchetti A.;Santino I.;Sartor A.;
2016

Abstract

Objectives: The spread of carbapenem-resistant Enterobacteriaceae (CRE) represents one of the most worrisome problems for clinical medicine worldwide. In Italy, the Antibiotic-Resistance-Istituto Superiore di Sanità surveillance network, in collaboration with the Committee for Antimicrobial Agents of the Italian Society of Clinical Microbiologists, promoted a study to investigate the carbapenem-resistance mechanisms, clonal relatedness and capsular typing of a recent collection of carbapenem-resistant Klebsiella pneumoniae (CR-KP). Methods: A total of 17 laboratories distributed across Italy collected all consecutive non-replicate CR-KP isolated from invasive infections during two different study periods (2011-12 and 2013). Carbapenemase genes were searched for by filter hybridization and confirmed by PCR and sequencing. KPC-producing K. pneumoniae (KPC-KP) were typed by PFGE and MLST. Capsular types were identified by wzi gene typing. Results: Of the collected K. pneumoniae isolates (n=461), the overall proportion of CR-KP was 36.2% (n=167). The majority (97%) of the CR-KP were positive for the blaKPC gene. Among the KPC-KP population, nine different STs were detected with the majority of isolates (94%) belonging to the clonal group (CG) 258. A subpopulation that belonged to ST512 and showed an identical PFGE profile represented the majority (57%) of KPC-KP strains, with a countrywide distribution. Capsular characterization showed the predominance of the wzi154, cps-2 capsular type (88.8% of all CG258 strains). ST258 strains were associated with both cps-1 and cps-2 capsular types, while ST512 was associated with cps-2 only. Conclusions: Although a trend to a polyclonal evolution of the Italian KPC-KP was noted, this study showed that the KPC-KP population remained largely oligoclonal with the wide diffusion of an ST512 lineage carrying cps-2 capsular type and producing the KPC-3 enzyme.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1454456
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