Aim: This study reports the characterization of carbapenem-resistant colonizing strains of K. pneumoniae. Methods: 650 stool samples were screened for carbapenem-resistant K. pneumoniae (CR-Kp). All strains were characterized for antibiotic susceptibility, typing features, main carbapenemases and extended-spectrum ß-lactamases. The carbapenemase transferability was assessed by interspecific conjugation. Results: Eighteen CR-Kp were multidrug resistant, five were KPC producing. A predominance of ST307 isolates, constituting the predominant cluster by PFGE analysis, was identified (50% were KPC-2 producers). Conjugation data showed the co-transfer of blaKPC-2, blaTEM-1, blaOXA-1, blaCTX-M-15 in a single large pKPN3-like plasmid. Conclusion: Our data pointed out the diversity of colonizing K. pneumoniae strains compared with clinical ones. The predominance of ST307 strains suggested an increased spreading, even in our area, of this high-risk clone.
Aim: This study reports the characterization of carbapenem-resistant colonizing strains of K. pneumoniae. Methods: 650 stool samples were screened for carbapenem-resistant K. pneumoniae (CR-Kp). All strains were characterized for antibiotic susceptibility, typing features, main carbapenemases and extended-spectrum ß-lactamases. The carbapenemase transferability was assessed by interspecific conjugation. Results: Eighteen CR-Kp were multidrug resistant, five were KPC producing. A predominance of ST307 isolates, constituting the predominant cluster by PFGE analysis, was identified (50% were KPC-2 producers). Conjugation data showed the co-transfer of blaKPC-2, blaTEM-1, blaOXA-1, blaCTX-M-15 in a single large pKPN3-like plasmid. Conclusion: Our data pointed out the diversity of colonizing K. pneumoniae strains compared with clinical ones. The predominance of ST307 strains suggested an increased spreading, even in our area, of this high-risk clone.
Entities:
Keywords:
ST307; blaKPC; carbapenem-resistant K. pneumoniae; conjugative plasmids
Authors: Marilena Agosta; Daniela Bencardino; Marta Argentieri; Laura Pansani; Annamaria Sisto; Marta Luisa Ciofi Degli Atti; Carmen D'Amore; Lorenza Putignani; Pietro Bagolan; Barbara Daniela Iacobelli; Andrea Dotta; Ludovica Martini; Luca Di Chiara; Mauro Magnani; Carlo Federico Perno; Francesca Andreoni; Paola Bernaschi Journal: Antibiotics (Basel) Date: 2022-03-23