Zhenpeng Li1, Zhao Cai2, Zeqiong Cai1, Yanhong Zhang3, Tongtong Fu1, Yongxin Jin1, Zhihui Cheng1, Shouguang Jin4, Weihui Wu1, Liang Yang5, Fang Bai1. 1. State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China. 2. Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore. 3. Affiliated Hospital of Nankai University, Tianjin, China. 4. Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA. 5. School of Medicine, Southern University of Science and Technology (SUSTech), Shenzhen, China.
Abstract
OBJECTIVES: A group of ST664 XDR Pseudomonas aeruginosa strains have been isolated from a burn clinic. Here we decipher their resistomes and likely mechanisms of resistance acquisition. METHODS: The complete nucleotide sequences of representative isolates were determined, by PacBio and Illumina MiSeq sequencing, and analysed for antimicrobial resistance (AMR) genes as well as sequence variations. S1-PFGE was used to determine the sizes and numbers of plasmids harboured by the isolates. Purified plasmid DNA was further sequenced by PacBio technology, closed manually and annotated by RAST. The mobility of plasmids was determined by conjugation assays. RESULTS: The XDR P. aeruginosa ST664 clone carries 11 AMR genes, including a blaKPC-2 gene that confers resistance to carbapenems. Most of the ST664 isolates carry three coexisting plasmids. blaKPC-2 and a cluster of three AMR genes (aadB-cmlA1-sul1) are encoded on a 475 kb megaplasmid pNK546a, which codes for an IncP-3-like replication and partitioning mechanism, but has lost the conjugative transfer system. Interestingly, however, pNK546a is mobilizable and can be transferred to P. aeruginosa PAO1 with the help of a co-residing IncP-7 conjugative plasmid. The blaKPC-2 gene is carried by an IS6100-ISKpn27-blaKPC-2-ΔISKpn6-Tn1403 mobile element, which might be brought into the ST664 clone by another co-resident IncP-1α plasmid, which is inclined to be lost. Moreover, pNK546a harbours multiple heavy metal (mercury, tellurite and silver) resistance modules. CONCLUSIONS: To the best of our knowledge, pNK546a is the first fully sequenced blaKPC-2-carrying megaplasmid from P. aeruginosa. These results give new insights into bacterial adaptation and evolution during nosocomial infections.
OBJECTIVES: A group of ST664 XDR Pseudomonas aeruginosa strains have been isolated from a burn clinic. Here we decipher their resistomes and likely mechanisms of resistance acquisition. METHODS: The complete nucleotide sequences of representative isolates were determined, by PacBio and Illumina MiSeq sequencing, and analysed for antimicrobial resistance (AMR) genes as well as sequence variations. S1-PFGE was used to determine the sizes and numbers of plasmids harboured by the isolates. Purified plasmid DNA was further sequenced by PacBio technology, closed manually and annotated by RAST. The mobility of plasmids was determined by conjugation assays. RESULTS: The XDR P. aeruginosa ST664 clone carries 11 AMR genes, including a blaKPC-2 gene that confers resistance to carbapenems. Most of the ST664 isolates carry three coexisting plasmids. blaKPC-2 and a cluster of three AMR genes (aadB-cmlA1-sul1) are encoded on a 475 kb megaplasmid pNK546a, which codes for an IncP-3-like replication and partitioning mechanism, but has lost the conjugative transfer system. Interestingly, however, pNK546a is mobilizable and can be transferred to P. aeruginosa PAO1 with the help of a co-residing IncP-7 conjugative plasmid. The blaKPC-2 gene is carried by an IS6100-ISKpn27-blaKPC-2-ΔISKpn6-Tn1403 mobile element, which might be brought into the ST664 clone by another co-resident IncP-1α plasmid, which is inclined to be lost. Moreover, pNK546a harbours multiple heavy metal (mercury, tellurite and silver) resistance modules. CONCLUSIONS: To the best of our knowledge, pNK546a is the first fully sequenced blaKPC-2-carrying megaplasmid from P. aeruginosa. These results give new insights into bacterial adaptation and evolution during nosocomial infections.
Authors: Paweł Urbanowicz; Ibrahim Bitar; Radosław Izdebski; Anna Baraniak; Elżbieta Literacka; Jaroslav Hrabák; Marek Gniadkowski Journal: Antimicrob Agents Chemother Date: 2021-03-18 Impact factor: 5.191
Authors: Catalina Díaz-Ríos; Marta Hernández; David Abad; Laura Álvarez-Montes; Athanasia Varsaki; David Iturbe; Jorge Calvo; Alain A Ocampo-Sosa Journal: Antibiotics (Basel) Date: 2021-04-23
Authors: James P J Hall; João Botelho; Adrian Cazares; David A Baltrus Journal: Philos Trans R Soc Lond B Biol Sci Date: 2021-11-29 Impact factor: 6.237