Genome plasticity favours double chromosomal Tn4401b-blaKPC-2 transposon insertion in the Pseudomonas aeruginosa ST235 clone

• Published in: BMC microbiology Vol. 19; no. 1; p. 45
• Main Authors: Abril, Deisy, Marquez-Ortiz, Ricaurte Alejandro, Castro-Cardozo, Betsy, Moncayo-Ortiz, José Ignacio, Olarte Escobar, Narda María, Corredor Rozo, Zayda Lorena, Reyes, Niradiz, Tovar, Catalina, Sánchez, Héctor Fabio, Castellanos, Jaime, Guaca-González, Yina Marcela, Llanos-Uribe, Carmen Elisa, Vanegas Gómez, Natasha, Escobar-Pérez, Javier
• Format: Journal Article
• Language: English
• Published: London BioMed Central Ltd 20.02.2019; BioMed Central
• Subjects: Antibiotics; Beta lactamases; Carbapenems; Chromosome rearrangements; Cities and towns; Cloning; DNA sequencing; Enzymes; Gene sequencing; Genes; Genetic aspects; Genomes; Genomic islands; Genomics; Infection; Infections; Insertion; Intelligence gathering; Intensive care; Medical research; Pathogens; Plastic properties; Plasticity; Pseudomonas aeruginosa; Surveillance; Transposition; Transposons; Colombia
• ISSN: 1471-2180; 1471-2180
• DOI: 10.1186/s12866-019-1418-6

Pseudomonas aeruginosa Sequence Type 235 is a clone that possesses an extraordinary ability to acquire mobile genetic elements and has been associated with the spread of resistance genes, including genes that encode for carbapenemases. Here, we aim to characterize the genetic platforms involved in resistance dissemination in bla.sub.KPC-2-positive P. aeruginosa ST235 in Colombia. In a prospective surveillance study of infections in adult patients attended in five ICUs in five distant cities in Colombia, 58 isolates of P. aeruginosa were recovered, of which, 27 (46.6%) were resistant to carbapenems. The molecular analysis showed that 6 (22.2%) and 4 (14.8%) isolates harboured the bla.sub.VIM and bla.sub.KPC-2 genes, respectively. The four bla.sub.KPC-2-positive isolates showed a similar PFGE pulsotype and belonged to ST235. Complete genome sequencing of a representative ST235 isolate shows a unique chromosomal contig of 7097.241 bp with eight different resistance genes identified and five transposons: a Tn6162-like with ant(2")-Ia, two Tn402-like with ant(3")-Ia and bla.sub.OXA-2 and two Tn4401b with bla.sub.KPC-2. All transposons were inserted into the genomic islands. Interestingly, the two Tn4401b copies harbouring bla.sub.KPC-2 were adjacently inserted into a new genomic island (PAGI-17) with traces of a replicative transposition process. This double insertion was probably driven by several structural changes within the chromosomal region containing PAGI-17 in the ST235 background. This is the first report of a double Tn4401b chromosomal insertion in P. aeruginosa, just within a new genomic island (PAGI-17). This finding indicates once again the great genomic plasticity of this microorganism.