Plasmids of different Klebsiella pneumoniae sequence types isolated from animal infections: same, similar or different?
Carola Venturini 1,2, Alicia Fajardo-Lubian 2,3, Sally Partridge 2,3,4, Ruth Zadoks 1
1 Sydney School of Veterinary Science, The University of Sydney, Sydney, NSW, Australia
2 Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, Westmead, NSW, Australia
3 Sydney School of Medicine, The University of Sydney, Sydney, NSW, Australia
4 Westmead Hospital, Western Sydney Local Health District, Westmead, NSW, Australia
Klebsiella pneumoniae is a high priority global public health threat. It can cause severe disease in animals and humans1 and is also a reservoir of antimicrobial resistance (AMR) and major trafficker of AMR genes, often located on transferable plasmids. The global epidemiology of K. pneumoniae infection is dominated by clones belonging to either highly resistant sequence types (ST) or highly virulent ones, seemingly on separate evolutionary trajectories2. We have shown that multiple K. pneumoniae isolates co-existing in the same infection site and belonging to different pathogenic clones were almost identical to isolates of the same ST from humans, except for AMR plasmid carriage3. To better understand AMR patterns in animal and human reservoirs and their link to specific pathogenic types, we have characterized the plasmids in K. pneumoniae isolated from farm animals in Australia (n>100), by whole genome sequencing (short and long read) and bioinformatic analysis, and compared them to plasmids in K. pneumoniae from humans. In common with plasmids found in humans3, most isolates (regardless of ST) carried related AMR F-type plasmids (FIIK7- and FIBK-type replicons) with the same accessory cargo perhaps linked to niche requirements (e.g. silver, copper and arsenic resistance, urea and iron transport). Unique HI3 plasmids were detected in most STs except highly virulent ones (i.e. ST25). AMR regions in plasmids have similar features and arrangements, and different clones with different virulence attributes seem to consistently have plasmids in common. This study shows that diverse AMR and virulence determinants located on plasmids are shared by resistant and virulent clones, indicating that the transmission of mobile genetic elements is a major driver of Klebsiella expansion in different niches. Our study highlights the importance of cross-monitoring of AMR reservoirs to understand the transfer of pathogens and genes between niches, to inform pathogen control practices.
References
[1] Paczosa MK & Mecsas M. 2016 Microbiol Mol Biol Reviews 80.3: 629-61
[2] Holt KE et al. 2015 PNAS 112:E3574-81
[3] Venturini C et al. 2022 Microbiol Spectr online: e0215821