Characterization of a Conjugative Multidrug Resistance IncP-2 Megaplasmid, pPAG5, from a Clinical Pseudomonas aeruginosa Isolate

Meng Li; Congcong Guan; Gaoyu Song; Xiaoxi Gao; Weina Yang; Tietao Wang; Yani Zhang

doi:10.1128/spectrum.01992-21

Microbiology Spectrum (Feb 2022)

Characterization of a Conjugative Multidrug Resistance IncP-2 Megaplasmid, pPAG5, from a Clinical Pseudomonas aeruginosa Isolate

Meng Li,
Congcong Guan,
Gaoyu Song,
Xiaoxi Gao,
Weina Yang,
Tietao Wang,
Yani Zhang

Affiliations

Meng Li: Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an, People’s Republic of China
Congcong Guan: Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an, People’s Republic of China
Gaoyu Song: Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an, People’s Republic of China
Xiaoxi Gao: Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an, People’s Republic of China
Weina Yang: Department of Clinical Laboratory, The Children’s Hospital of Xi’an City, Xi’an, People’s Republic of China
Tietao Wang: Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an, People’s Republic of China
Yani Zhang: Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an, People’s Republic of China

DOI: https://doi.org/10.1128/spectrum.01992-21
Journal volume & issue: Vol. 10, no. 1

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ABSTRACT The spread of resistance genes via horizontal plasmid transfer plays a significant role in the formation of multidrug-resistant (MDR) Pseudomonas aeruginosa strains. Here, we identified a megaplasmid (ca. 513 kb), designated pPAG5, which was recovered from a clinical multidrug-resistant P. aeruginosa PAG5 strain. The pPAG5 plasmid belonged to the IncP-2 incompatibility group. Two large multidrug resistance regions (MDR-1 and MDR-2) and two heavy metal resistance operons (merEDACPTR and terZABCDE) were identified in the pPAG5 plasmid. Genetic analysis demonstrated that the formation of MDR regions was mediated by several homologous recombination events. Further conjugation assays identified that pPAG5 could be transferred to P. aeruginosa but not Escherichia coli. Antimicrobial susceptibility testing on transconjugants demonstrated that pPAG5 was capable of transferring resistance genes to transconjugants and producing a multidrug-resistant phenotype. Comparative analysis revealed that pPAG5 and related plasmids shared an overall similar backbone, including genes essential for replication (repA), partition (par), and conjugal transfer (tra). Further phylogenetic analysis showed that pPAG5 was closely related to plasmids pOZ176 and pJB37, both of which are members of the IncP-2-type plasmid group. IMPORTANCE The emergence and spread of plasmid-associated multidrug resistance in bacterial pathogens is a key global threat to public health. It is important to understand the mechanisms of the formation and evolution of these plasmids in patients, hospitals, and the environment. In this study, we detailed the genetic characteristics of a multidrug resistance IncP-2 megaplasmid, pPAG5, and investigated the formation of its MDR regions and evolution. To the best of our knowledge, plasmid pPAG5 is the largest multidrug resistance plasmid ever sequenced in the Pseudomonas genus. Our results may provide further insight into the formation of multidrug resistance plasmids in bacteria and the molecular evolution of plasmids.

Published in Microbiology Spectrum

ISSN: 2165-0497 (Online)
Publisher: American Society for Microbiology
Country of publisher: United States
LCC subjects: Science: Microbiology
Website: https://journals.asm.org/journal/spectrum

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