Emerging high-risk ST101 and ST307 carbapenem-resistant Klebsiella pneumoniae clones from bloodstream infections in Southern Italy

• Main Authors: Daniela Loconsole, Marisa Accogli, Anna Lisa De Robertis, Loredana Capozzi, Angelica Bianco, Anna Morea, Rosanna Mallamaci, Michele Quarto, Antonio Parisi, Maria Chironna
• Format: Article
• Language: English
• Published: BMC 2020-06-01
• Series: Annals of Clinical Microbiology and Antimicrobials
• Subjects: Carbapenem-resistant Klebsiella pneumoniae; Bloodstream infections; Drug resistance; ST101; ST307; Whole genome sequencing
• Online Access: http://link.springer.com/article/10.1186/s12941-020-00366-y

Abstract Background Carbapenem-resistant Klebsiella pneumoniae (CR-KP) is an urgent public health issue in Italy. This pattern of resistance is due mainly to dissemination of carbapenemase genes. Molecular characterization of carbapenem-resistant Klebsiella pneumoniae (CR-KP) strains was performed over a three-year period. In-depth analysis was performed on a subset of emerging CR-KP ST101 and ST307 clones. Methods A prospective study was performed on 691 patients with CR-KP bloodstream infections hospitalized in 19 hospitals located in three large provinces in Southern Italy. Carbapenemase genes were identified via genotyping methods. Multi-locus sequence typing (MLST) and Whole Genome Sequencing (WGS) were carried out on ST101 and ST307 isolates. Results Among the CR-KP isolates, bla KPC was found in 95.6%, bla VIM was found in 3.5%, bla NDM was found in 0.1% and bla OXA-48 was found in 0.1%. The bla KPC-3 variant was identified in all 104 characterized KPC-KP isolates. MLST of 231 representative isolates revealed ST512 in 45.5%, ST101 in 20.3% and ST307 in 18.2% of the isolates. cgMLST of ST307 and ST101 isolates revealed presence of more than one beta-lactam resistance gene. Amino acid substitution in the chromosomal colistin-resistance gene pmrB was found in two ST101 isolates. Conclusions ST512 is widespread in Southern Italy, but ST101 and ST307 are emerging since they were found in a significant proportion of cases. Aggressive infection control measures and a continuous monitoring of these high-risk clones are necessary to avoid rapid spread of CR-KP, especially in hospital settings.