Establishment and multi drug resistance evolution of ST235 Pseudomonas aeruginosa strains in the intensive care unit of a Colombian hospital

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

“…To perform the phylogenetic analysis and comparative genomics, the 43 publicly available P. aeruginosa ST235 genomes at the time were included (41 drafts and 2 complete genomes available at the NCBI genomes repository in January 2017), plus the genomes of the 24pae112 and 9Ps50 isolates (Additional file 1: Table S1). This 9Ps50 isolate was previously identified in 2006 by our group, causing an infection in institution C (included in this study), and did not harbour bla KPC-2 [25]. To build the phylogenetic tree based on the core-genome SNPs, partially assembled genomes were annotated using Prokka v1.11 [33], and an alignment of the concatenated core genes (genes present in all genomes with ≥90% of nucleotide identity) was created with Roary [35] using PRANK [36].…”

“…In Colombia, the ST235 clone has become prevalent since 2005 and has suffered an evolution in clinically important resistance genes by lateral gene transfer (LGT), e.g. some strains have acquired an atypical active class 1 integron with an unusual 3′ consensus sequence ( tni module), which can provide a putative self-transposition ability [25], the acquisition of IS 26 and the bla KPC-2 gene, which are most frequent in Enterobacteriaceae but rare in P. aeruginosa [2, 25]. In this study, after active clinical surveillance in the ICU at five distant cities, we found a broad population distribution of P. aeruginosa in Colombia; nonetheless, the ST235 clone was the only one harbouring bla KPC-2 , and interestingly, those ST235 isolates harboured two copies of this gene that were located in two Tn 4401b transposons in a new genomic island (GI) at the chromosome.…”

Phenotypic and Genomic Comparison of the Two Most Common ExoU-Positive Pseudomonas aeruginosa Clones, PA14 and ST235

“…Most ST235 strains were collected between 1998 and 2007. They are susceptible to the common antipseudomonal agents in contrast to the ST235 isolates reported from the last decade that were typically either multidrug or extensively drug resistant (21,22,(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49). Thus, our strains may be of interest for the research community to study the unusual features of ST235 in a normal antibiotic-sensitive background.…”

“…This work now introduces the high-risk clone ST235 to be the third most common clone in the P. aeruginosa population. So far, almost all publications have dealt with the infection epidemiology and antimicrobial resistance of the ExoU-positive ST235 clone (subject of 88% of publications, PubMed, search term Pseudomonas aeruginosa ST235, assessed 6 March 2020) (37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49). Antibiotic resistance determinants of MDR and extensively drugresistant (XDR) ST235 strains have been characterized in detail (40-43, 45-47, 49); otherwise, our current knowledge about the lifestyle, physiology, and metabolism of the pandemic ST235 clone is scarce (50).…”

Tn6026 and Tn6029 are found in complex resistance regions mobilised by diverse plasmids and chromosomal islands in multiple antibiotic resistant Enterobacteriaceae

“…IS26 has garnered a great deal of interest for its role in the formation of multiple antibiotic resistance regions on plasmids and in the chromosomes of phylogenetically diverse Gram negative bacteria including Escherichia coli [1][2][3][4][5], various Salmonella enterica serovars [6,7], Pseudomonas aeruginosa [8,9], Klebsiella pneumoniae [10], Actinobacter baumannii [11,12], Proteus mirabilis [13,14], Citrobacter freundii [15], Serratia marcescens [16], Enterobacter cloacae, Pantoea spp [17], Stenotrophomonas maltophilia (GenBank entry KM649682.1), Klebsiella oxytoca (GenBank entry KJ541681.1), Aeromonas salmonicida [18]and Vibrio cholerae (GenBank entry KM083064.1). IS26 is found flanking genes encoding resistance to a wide range of antibiotics including fosfomycin [19], kanamycin and neomycin [20], ampicillin, streptomycin and sulfonamides [6], chloramphenicol, florfenicol and clindamycin [21,22], and antibiotic classes including extended spectrum β-lactamases (ESBLs, e.g.…”