From Pan-genome to the Genomic Context of the Two Integrons of ST-111 Pseudomonas Aeruginosa AG1: A VIM-2-carrying Old-acquaintance and a Novel Imp-18-carrying Integron

2020 ◽  
Author(s):  
Jose Arturo Molina-Mora ◽  
Raquel García Batán ◽  
Fernando García

Abstract Background Pseudomonas aeruginosa is an opportunist and versatile organism responsible for infections among immunocompromised hosts. This pathogen has high intrinsic resistance to most antimicrobials, including critical strains due to resistance to carbapenems, a last-resort antibiotic. P. aeruginosa AG1 (PaeAG1) is a Costa Rican high-risk ST-111 strain with resistance to multiple antibiotics, including carbapenems due to the activity of both VIM-2 and IMP-18 metallo-β-lactamases (MBLs). These genes are harbored in two class 1 integrons, belonging to one out of the 57 PaeAG1 genomic islands. However, the genomic context related to these determinants in PaeAG1 and other P. aeruginosa strains is unclear. Thus, we implemented a comparative genomic approach to define and up-date the phylogenetic relationship among complete P. aeruginosa genomes using a pan-genome analysis. We also studied the PaeAG1 genomic islands content in other strains and the architecture of genomic regions around the VIM-2- and IMP-18-carrying integrons. Results With 211 strains, the up-dated P. aeruginosa pan-genome revealed that complete genome sequences are able to separate clones by MLST profile (ST), including a clear ST-111 cluster with PaeAG1. The PaeAG1 genomic islands were found to define a diverse presence/absence pattern among related genomes, but content was related to phylogenetic relationships. Finally, landscape reconstruction of specific genomic regions showed that VIM-2-carrying integron (In59-like) is an old-acquaintance element harbored in a known genomic region completely found in other two ST-111 strains. In addition, PaeAG1 has an exclusive genomic region containing a novel IMP-18-carrying integron (registered as In1666), with an arrangement never reported before. Conclusions We provide new insights about the genomic determinants associated with the resistance to carbapenems in the high-risk PaeAG1 using comparative genomics. With the pan-genome analysis and the comparison of PaeAG1 genomic islands in other strains, it was possible to describe the genomic landscape of the two MBLs-carrying integrons, including an old-acquaintance element carrying VIM-2 and a new IMP-18-carrying integron.

2020 ◽  
Author(s):  
Jose Arturo Molina-Mora ◽  
Diana Chinchilla-Montero ◽  
Raquel García Batán ◽  
Fernando García

Abstract Pseudomonas aeruginosa is an opportunist and versatile organism responsible for infections mainly in immunocompromised hosts. This pathogen has high intrinsic resistance to most antimicrobials. P. aeruginosa AG1 (PaeAG1) is a Costa Rican high-risk ST-111 strain with resistance to multiple antibiotics, including carbapenems, due to the activity of VIM-2 and IMP-18 metallo-β-lactamases (MBLs). These genes are harbored in two class 1 integrons located inone out of the 57 PaeAG1 genomic islands. However, the genomic context associated to these determinants in PaeAG1 and other P. aeruginosa strains is unclear. Thus, we first assessed the transcriptional activity of VIM-2 and IMP-18 genes when exposed to imipenem (a carbapenem) by RT-qPCR. To select related genomes to PaeAG1, we implemented a pan-genome analysis to define and up-date the phylogenetic relationship among complete P. aeruginosa genomes. We also studied the PaeAG1 genomic islands content in the related strains and finally we described the architecture and possible evolutionary steps of the genomic regions around the VIM-2- and IMP-18-carrying integrons.Expression of VIM-2 and IMP-18 genes was demonstrated to be induced after imipenem exposure. In a subsequent comparative genomics analysis with 211 strains, the P. aeruginosa pan-genome revealed that complete genome sequences are able to separate clones by MLST profile, including a clear ST-111 cluster with PaeAG1. The PaeAG1 genomic islands were found to define a diverse presence/absence pattern among related genomes. Finally, landscape reconstruction of genomic regions showed that VIM-2-carrying integron (In59-like) is an old-acquaintance element harbored in the same known region found in other two ST-111 strains. Also, PaeAG1 has an exclusive genomic region containing a novel IMP-18-carrying integron (registered as In1666), with an arrangement never reported before. Altogether, we provide new insights about the genomic determinants associated with the resistance to carbapenems in this high-risk P. aeruginosa using comparative genomics.


2021 ◽  
Author(s):  
Érica L. Fonseca ◽  
Sérgio M. Morgado ◽  
Raquel V. Caldart ◽  
Fernanda Freitas ◽  
Ana Carolina P. Vicente

ABSTRACTPseudomonas aeruginosa has been considered one of the major nosocomial pathogens associated with elevated morbidity and mortality worldwide. Outbreaks have been associated with few high-risk pandemic P. aeruginosa lineages, presenting a remarkable antimicrobial resistance. However, the biological features involved with the persistence and spread of such lineages among clinical settings remain to be unravel. This study reports the emergence of the ST309 P. aeruginosa lineage in South America/Brazil, more precisely, in the Amazon region. Global genomic analyses were performed with the Brazilian strain (PA834) and more 41 complete and draft ST309 genomes publicly available, giving insights about ST309 epidemiology and its resistome and mobilome. Antimicrobial susceptibility tests revealed that the Brazilian PA834 strain presented the XDR phenotype, which was mainly due to intrinsic resistance mechanisms. Genomic analyses revealed a heterogeneous distribution of acquired antimicrobial resistance genes among ST309 genomes, which included blaVIM-2, blaIMP-15 and qnrVC1, all of them associated with class 1 integrons. The mobilome mining showed the presence of Integrative and Conjugative Elements, transposons and genomic islands harbouring a huge arsenal of hevy metal resistance genes. Moreover, these elements also carried genes involved with virulence and adaptive traits. Therefore, the presence of such genes in ST309 lineage possibly accounted for the global spread and persistence of this emerging clone, and for its establishment as a pandemic lineage of clinical importance.


PLoS ONE ◽  
2016 ◽  
Vol 11 (8) ◽  
pp. e0159419 ◽  
Author(s):  
Ikuo Uchiyama ◽  
Jacob Albritton ◽  
Masaki Fukuyo ◽  
Kenji K. Kojima ◽  
Koji Yahara ◽  
...  

2009 ◽  
Vol 53 (7) ◽  
pp. 2902-2907 ◽  
Author(s):  
Tsuey-Ching Yang ◽  
Yi-Wei Huang ◽  
Rouh-Mei Hu ◽  
Shao-Cheng Huang ◽  
Yu-Tzu Lin

ABSTRACT Two ampD homologues, ampD I and ampD II, of Stenotrophomonas maltophilia have been cloned and analyzed. Comparative genomic analysis revealed that the genomic context of the ampD II genes is quite different, whereas that of the ampD I genes is more conserved in S. maltophilia strains. The ampD system of S. maltophilia is distinct from that of the Enterobacteriaceae and Pseudomonas aeruginosa in three respects. (i) AmpDI of S. maltophilia is not encoded in an ampDE operon, in contrast to what happens in the Enterobacteriaceae and P. aeruginosa. (ii) The AmpD systems of the Enterobacteriaceae and P. aeruginosa are generally involved in the regulation of ampR-linked ampC gene expression, while AmpDI of S. maltophilia is responsible for the regulation of two intrinsic β-lactamase genes, of which the L2 gene, but not the L1 gene, is linked to ampR. (iii) S. maltophilia exhibits a one-step L1 and L2 gene derepression model involving ampD I, distinct from the two- or three-step derepression of the Enterobacteriaceae and P. aeruginosa. Moreover, the ampD I and ampD II genes are constitutively expressed and not regulated by the inducer and AmpR protein, and the expression of ampD II is weaker than that of ampD I. Finally, AmpDII is not associated with the derepression of β-lactamases, and its role in S. maltophilia remains unclear.


F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 265 ◽  
Author(s):  
Oksana Lukjancenko ◽  
Martin Christen Thomsen ◽  
Mette Voldby Larsen ◽  
David Wayne Ussery

PanFunPro is a tool for pan-genome analysis that integrates functional domains from three Hidden Markov Models (HMM) collections, and uses this information to group homologous proteins into families based on functional domain content. We use PanFunPro to compare a set of Lactobacillus and Streptococcus genomes. The example demonstrates that this method can provide analysis of differences and similarities in protein content within user-defined sets of genomes. PanFunPro can find various applications in a comparative genomic study, starting with the basic comparison of newly sequenced isolates to already existing strains, and an estimation of shared and specific genomic content. Furthermore, it can potentially be used in the determination of target sequences for in silico bacterial identification, as well as for epidemiological studies.


2020 ◽  
Vol 6 (12) ◽  
Author(s):  
Lin Zhao ◽  
Hongyou Chen ◽  
Xavier Didelot ◽  
Zhenpeng Li ◽  
Yinghui Li ◽  
...  

Vibrio parahaemolyticus is an important cause of foodborne gastroenteritis globally. Thermostable direct haemolysin (TDH) and the TDH-related haemolysin are the two key virulence factors in V. parahaemolyticus. Vibrio pathogenicity islands harbour the genes encoding these two haemolysins. The serotyping of V. parahaemolyticus is based on the combination of O and K antigens. Frequent recombination has been observed in V. parahaemolyticus , including in the genomic regions encoding the O and K antigens. V. parahaemolyticus serotype O4:K12 has caused gastroenteritis outbreaks in the USA and Spain. Recently, outbreaks caused by this serotype of V. parahaemolyticus have been reported in China. However, the relationships among this serotype of V. parahaemolyticus strains isolated in different regions have not been addressed. Here, we investigated the genome variation of the V. parahaemolyticus serotype O4:K12 using the whole-genome sequences of 29 isolates. We determined five distinct lineages in this strain collection. We observed frequent recombination among different lineages. In contrast, little recombination was observed within each individual lineage. We showed that the lineage of this serotype of V. parahaemolyticus isolated in America was different from those isolated in Asia and identified genes that exclusively existed in the strains isolated in America. Pan-genome analysis showed that strain-specific and cluster-specific genes were mostly located in the genomic islands. Pan-genome analysis also showed that the vast majority of the accessory genes in the O4:K12 serotype of V. parahaemolyticus were acquired from within the genus Vibrio . Hence, we have shown that multiple distinct lineages exist in V. parahaemolyticus serotype O4:K12 and have provided more evidence about the gene segregation found in V. parahaemolyticus isolated in different continents.


2006 ◽  
Vol 188 (11) ◽  
pp. 4037-4050 ◽  
Author(s):  
Bridget R. Kulasekara ◽  
Hemantha D. Kulasekara ◽  
Matthew C. Wolfgang ◽  
Lisa Stevens ◽  
Dara W. Frank ◽  
...  

ABSTRACT ExoU is a potent Pseudomonas aeruginosa cytotoxin translocated into host cells by the type III secretion system. A comparison of genomes of various P. aeruginosa strains showed that that the ExoU determinant is found in the same polymorphic region of the chromosome near a tRNALys gene, suggesting that exoU is a horizontally acquired virulence determinant. We used yeast recombinational cloning to characterize four distinct ExoU-encoding DNA segments. We then sequenced and annotated three of these four genomic regions. The sequence of the largest DNA segment, named ExoU island A, revealed many plasmid- and genomic island-associated genes, most of which have been conserved across a broad set of β- and γ-Proteobacteria. Comparison of the sequenced ExoU-encoding genomic islands to the corresponding PAO1 tRNALys-linked genomic island, the pathogenicity islands of strain PA14, and pKLC102 of clone C strains allowed us to propose a mechanism for the origin and transmission of the ExoU determinant. The evolutionary history very likely involved transposition of the ExoU determinant onto a transmissible plasmid, followed by transfer of the plasmid into different P. aeruginosa strains. The plasmid subsequently integrated into a tRNALys gene in the chromosome of each recipient, where it acquired insertion sequences and underwent deletions and rearrangements. We have also applied yeast recombinational cloning to facilitate a targeted mutagenesis of ExoU island A, further demonstrating the utility of the specific features of the yeast capture vector for functional analyses of genes on large horizontally acquired genetic elements.


2021 ◽  
Author(s):  
Jun Ishigohoka ◽  
Karen Bascón-Cardozo ◽  
Andrea Bours ◽  
Janina Fuß ◽  
Arang Rhie ◽  
...  

The patterns of genetic relatedness among individuals vary along the genome, representing fluctuation of local ancestry. The factors responsible for this variation have not been well studied in wild animals with ecological and behavioural relevance. Here, we characterise the genomic architecture of genetic relatedness in the Eurasian blackcap, an iconic songbird species in ecology and quantitative genetics of migratory behaviour. We identify 23 genomic regions with deviated local relatedness patterns, using a chromosome-level de novo assembly of the blackcap genome and whole-genome resequencing data of 179 individuals from nine populations with diverse migratory phenotypes. Five genomic regions show local relatedness patterns of polymorphic inversions, three of which are syntenic to polymorphic inversions known in the zebra finch. Phylogenetic analysis reveals these three polymorphic inversions evolved independently in the blackcap and zebra finch indicating convergence of polymorphic inversions. Population genetic analyses in these three inversions in the blackcap suggest balancing selection between two haplotypes in one locus and background selection in the other two loci. One genomic region with deviated local relatedness is under selection against gene flow by population-specific reduction in recombination rate. Other genomic islands including 11 pericentromeric regions consist of evolutionarily conserved and non-conserved recombination cold-spots under background selection. Two of these regions with non-conserved recombination suppression are known to be associated with population-specific migratory phenotypes, where local relatedness patterns support additional effects of population-specific selection. These results highlight how different forms of recombination suppression and selection jointly affect heterogeneous genomic landscape of local ancestries.


2020 ◽  
Vol 58 (9) ◽  
Author(s):  
Austin Wesevich ◽  
Granger Sutton ◽  
Felicia Ruffin ◽  
Lawrence P. Park ◽  
Derrick E. Fouts ◽  
...  

ABSTRACT Enterobacter aerogenes was recently renamed Klebsiella aerogenes. This study aimed to identify differences in clinical characteristics, outcomes, and bacterial genetics among patients with K. aerogenes versus Enterobacter species bloodstream infections (BSI). We prospectively enrolled patients with K. aerogenes or Enterobacter cloacae complex (Ecc) BSI from 2002 to 2015. We performed whole-genome sequencing (WGS) and pan-genome analysis on all bacteria. Overall, 150 patients with K. aerogenes (46/150 [31%]) or Ecc (104/150 [69%]) BSI were enrolled. The two groups had similar baseline characteristics. Neither total in-hospital mortality (13/46 [28%] versus 22/104 [21%]; P = 0.3) nor attributable in-hospital mortality (9/46 [20%] versus 13/104 [12%]; P = 0.3) differed between patients with K. aerogenes versus Ecc BSI, respectively. However, poor clinical outcome (death before discharge, recurrent BSI, and/or BSI complication) was higher for K. aerogenes than Ecc BSI (32/46 [70%] versus 42/104 [40%]; P = 0.001). In a multivariable regression model, K. aerogenes BSI, relative to Ecc BSI, was predictive of poor clinical outcome (odds ratio 3.3; 95% confidence interval 1.4 to 8.1; P = 0.008). Pan-genome analysis revealed 983 genes in 323 genomic islands unique to K. aerogenes isolates, including putative virulence genes involved in iron acquisition (n = 67), fimbriae/pili/flagella production (n = 117), and metal homeostasis (n = 34). Antibiotic resistance was largely found in Ecc lineage 1, which had a higher rate of multidrug resistant phenotype (23/54 [43%]) relative to all other bacterial isolates (23/96 [24%]; P = 0.03). K. aerogenes BSI was associated with poor clinical outcomes relative to Ecc BSI. Putative virulence factors in K. aerogenes may account for these differences.


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