scholarly journals A large self-transmissible plasmid from Nigeria confers resistance to multiple antibacterials without a carrying cost

2019 ◽  
Author(s):  
Rubén Monárrez ◽  
Molly Braun ◽  
Olivia Coburn-Flynn ◽  
João Botelho ◽  
Babatunde W. Odeotyin ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Open Reading Frames ◽  
Multiple Loci ◽  
Large Size ◽  
Transmissible Plasmid ◽  
Resistance Plasmids ◽  
Evolutionary Success ◽  
Restricted Use ◽  
Isogenic Strains ◽  
Reading Frames

AbstractAntimicrobial resistance is rapidly expanding, in a large part due to mobile genetic elements. We screened 94 fecal fluoroquinolone-resistantEscherichia coliisolates from Nigeria for six plasmid-mediated quinolone resistance (PMQR) genes. Sixteen isolates harbored at least one of the PMQR genes and four were positive foraac-6-Ib-cr. In one strain,aac-6-Ib-crwas mapped to a 125 Kb self-transmissible IncFII plasmid, pMB2, which also bearsblaCTX-M-15, seven other functional resistance genes and multiple resistance pseudogenes. We hypothesized that pMB2 had been selected by antimicrobials and that its large size would confer a growth disadvantage. However, laboratory strains carrying pMB2 grew at least as fast as isogenic strains lacking the plasmid in both rich and minimal media. We excised a 32 Kb fragment containing thesitABCDand another putative transporter,pefB, apapBhomolog, and several open-reading frames of unknown function. The resulting 93 Kb mini-plasmid conferred slower growth rates and lower fitness than wildtype pMB2. Trans-complementing the deletion with the clonedsitABCDgenes confirmed that they accounted for the growth advantage conferred by pMB2 in iron-depleted media. The mini-plasmid additionally conferred autoaggregation and was less transmissible and both phenotypes could be complemented with apefBclone. pMB2 is a large plasmid with a flexible resistance region that contains multiple loci that can account for evolutionary success in the absence of antimicrobials. Ancillary functions conferred by resistance plasmids can mediate their retention and transmissibility, worsening the trajectory for antimicrobial resistance and potentially circumventing efforts to contain resistance through restricted use.

scholarly journals A large self-transmissible resistance plasmid from Nigeria contains genes that ameliorate a carrying cost

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rubén Monárrez ◽  
Molly Braun ◽  
Olivia Coburn-Flynn ◽  
João Botelho ◽  
Babatunde W. Odetoyin ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Open Reading Frames ◽  
Multiple Resistance ◽  
Large Plasmid ◽  
Resistance Plasmids ◽  
Evolutionary Success ◽  
Minimal Media ◽  
Restricted Use ◽  
Isogenic Strains ◽  
Reading Frames

AbstractAntimicrobial resistance is rapidly expanding, in a large part due to mobile genetic elements. We screened 94 fecal fluoroquinolone-resistant Escherichia coli isolates from Nigeria for six plasmid-mediated quinolone resistance (PMQR) genes. Sixteen isolates harbored at least one of the PMQR genes and four were positive for aac-6-Ib-cr. In one strain, aac-6-Ib-cr was mapped to a 125 Kb self-transmissible IncFII plasmid, pMB2, which also bears blaCTX-M-15, seven other functional resistance genes and multiple resistance pseudogenes. Laboratory strains carrying pMB2 grew faster than isogenic strains lacking the plasmid in both rich and minimal media. We excised a 32 Kb fragment containing transporter genes and several open-reading frames of unknown function. The resulting 93 Kb mini-plasmid conferred slower growth rates and lower fitness than wildtype pMB2. Trans-complementing the deletion with the cloned sitABCD genes confirmed that they accounted for the growth advantage conferred by pMB2 in iron-depleted media. pMB2 is a large plasmid with a flexible resistance region that contains loci that can account for evolutionary success in the absence of antimicrobials. Ancillary functions conferred by resistance plasmids can mediate their retention and transmissibility, worsening the trajectory for antimicrobial resistance and potentially circumventing efforts to contain resistance through restricted use.

scholarly journals Evolutionary History of Cucumber Mosaic Virus Deduced by Phylogenetic Analyses

2002 ◽  
Vol 76 (7) ◽  
pp. 3382-3387 ◽  
Author(s):  
Marilyn J. Roossinck
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Virus Isolate ◽  
Phylogenetic Analyses ◽  
Open Reading Frames ◽  
Broad Host Range ◽  
Nontranslated Region ◽  
History Of ◽  
Evolutionary Success ◽  
Reading Frames

ABSTRACT Cucumber mosaic virus (CMV) is an RNA plant virus with a tripartite genome and an extremely broad host range. Previous evolutionary analyses with the coat protein (CP) and 5′ nontranslated region (NTR) of RNA 3 suggested subdivision of the virus into three groups, subgroups IA, IB, and II. In this study 15 strains of CMV whose nucleotide sequences have been determined were used for a complete phylogenetic analysis of the virus. The trees estimated for open reading frames (ORFs) located on the different RNAs were not congruent and did not completely support the subgrouping indicated by the CP ORF, indicating that different RNAs had independent evolutionary histories. This is consistent with a reassortment mechanism playing an important role in the evolution of the virus. The evolutionary trees of the 1a and 3a ORFs were more compact and displayed more branching than did those of the 2a and CP ORFs. This may reflect more rigid host-interactive constraints exerted on the 1a and 3a ORFs. In addition, analysis of the 3′ NTR that is conserved among all RNAs indicated that evolutionary constraints on this region are specific to the RNA component rather than the virus isolate. This indicates that functions other than replication are encoded in the 3′ NTR. Reassortment may have led to the genetic diversity found among CMV strains and contributed to its enormous evolutionary success.

scholarly journals A plasmid-encoded papB paralogue modulates autoaggregation of Escherichia coli transconjugants

2020 ◽  
Author(s):  
Ruben Monarrez ◽  
Iruka Okeke
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Genetic Basis ◽  
Mobile Element ◽  
Enteric Bacteria ◽  
Selective Advantage ◽  
Open Reading Frames ◽  
Bacterial Strains ◽  
Element Bearing ◽  
Reading Frames

Abstract Objective: Plasmids are key to antimicrobial resistance transmission among enteric bacteria. It is becoming increasingly clear that resistance genes alone do not account for the selective advantage of plasmids and bacterial strains that harbor them. Deletion of a 32 Kb fitness-conferring region of pMB2, a conjugative resistance plasmid, produced a hyper-autoaggregation phenotype in laboratory Escherichia coli. This study sought to determine the genetic basis for hyper-autoaggregation conferred by the pMB2-derived mini-plasmid. Results: The 32 Kb fragment deleted from pMB2 included previously characterized nutrient acquisition genes as well as putative transposase and integrase genes, a 272 bp papB/ pefB-like gene, and several open-reading frames of unknown function. We cloned the papB/ pefB paralogue and found it sufficient to temper the hyper-autoaggregation phenotype. Hyper-autoaggregation conferred by the mini-plasmid did not occur in a fim-negative background. This study has identified and characterized a gene capable of down-regulating host adhesins and has shown that trans-acting papB/pefB paralogues can occur outside the context of an adhesin cluster. This plasmid-mediated modification of a bacterial host’s colonization program may optimize horizontal transfer of the mobile element bearing the genes.

scholarly journals A plasmid-encoded papB paralogue modulates autoaggregation of Escherichia coli transconjugants

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Rubén Monárrez ◽  
Iruka N. Okeke
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Genetic Basis ◽  
Mobile Element ◽  
Enteric Bacteria ◽  
Selective Advantage ◽  
Open Reading Frames ◽  
Bacterial Strains ◽  
Element Bearing ◽  
Reading Frames

Abstract Objective Plasmids are key to antimicrobial resistance transmission among enteric bacteria. It is becoming increasingly clear that resistance genes alone do not account for the selective advantage of plasmids and bacterial strains that harbor them. Deletion of a 32 Kb fitness-conferring region of pMB2, a conjugative resistance plasmid, produced a hyper-autoaggregation phenotype in laboratory Escherichia coli. This study sought to determine the genetic basis for hyper-autoaggregation conferred by the pMB2-derived mini-plasmid. Results The 32 Kb fragment deleted from pMB2 included previously characterized nutrient acquisition genes as well as putative transposase and integrase genes, a 272 bp papB/ pefB-like gene, and several open-reading frames of unknown function. We cloned the papB/ pefB paralogue and found it sufficient to temper the hyper-autoaggregation phenotype. Hyper-autoaggregation conferred by the mini-plasmid did not occur in a fim-negative background. This study has identified and characterized a gene capable of down-regulating host adhesins and has shown that trans-acting papB/pefB paralogues can occur outside the context of an adhesin cluster. This plasmid-mediated modification of a bacterial host’s colonization program may optimize horizontal transfer of the mobile element bearing the genes.

scholarly journals Comparative Genomic Analysis of Acinetobacter oleivorans DR1 To Determine Strain-Specific Genomic Regions and Gentisate Biodegradation

2011 ◽  
Vol 77 (20) ◽  
pp. 7418-7424 ◽  
Author(s):  
Jaejoon Jung ◽  
Eugene L. Madsen ◽  
Che Ok Jeon ◽  
Woojun Park
Keyword(s):  
Metabolic Pathways ◽  
Genomic Analysis ◽  
Metal Resistance ◽  
Genomic Region ◽  
Open Reading Frames ◽  
Comparative Genomic ◽  
Content Type ◽  
Large Size ◽  
Genomic Regions ◽  
Reading Frames

ABSTRACTThe comparative genomics ofAcinetobacter oleivoransDR1 assayed withA. baylyiADP1,A. calcoaceticusPHEA-2, andA. baumanniiATCC 17978 revealed that the incorporation of phage-related genomic regions and the absence of transposable elements have contributed to the large size (4.15 Mb) of the DR1 genome. A horizontally transferred genomic region and a higher proportion of transcriptional regulator- and signal peptide-coding genes were identified as characteristics of the DR1 genome. Incomplete glucose metabolism, metabolic pathways of aromatic compounds, biofilm formation, antibiotics and metal resistance, and natural competence genes were conserved in four compared genomes. Interestingly, only strain DR1 possesses gentisate 1,2-dioxygenase (nagI) and grows on gentisate, whereas other species cannot. Expression of thenagIgene was upregulated during gentisate utilization, and four downstream open reading frames (ORFs) were cotranscribed, supporting the notion that gentisate metabolism is a unique characteristic of strain DR1. The genomic analysis of strain DR1 provides additional insights into the function, ecology, and evolution ofAcinetobacterspecies.

scholarly journals A plasmid-encoded papB paralogue modulates autoaggregation of Escherichia coli transconjugants

2020 ◽  
Author(s):  
Ruben Monarrez ◽  
Iruka Okeke
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Genetic Basis ◽  
Mobile Element ◽  
Enteric Bacteria ◽  
Selective Advantage ◽  
Open Reading Frames ◽  
Bacterial Strains ◽  
Element Bearing ◽  
Reading Frames

Abstract Objective: Plasmids are key to antimicrobial resistance transmission among enteric bacteria. It is becoming increasingly clear that resistance genes alone do not account for the selective advantage of plasmids and bacterial strains that harbor them. Deletion of a 32 Kb fitness-conferring region of pMB2, a conjugative resistance plasmid, produced a hyper-autoaggregation phenotype in laboratory Escherichia coli. This study sought to determine the genetic basis for hyper-autoaggregation conferred by the pMB2-derived mini-plasmid. Results: The 32 Kb fragment deleted from pMB2 included previously characterized nutrient acquisition genes as well as putative transposase and integrase genes, a 272 bp papB/ pefB-like gene, and several open-reading frames of unknown function. We cloned the papB/ pefB paralogue and found it sufficient to temper the hyper-autoaggregation phenotype. Hyper-autoaggregation conferred by the mini-plasmid did not occur in a fim-negative background. This study has identified and characterized a gene capable of down-regulating host adhesins and has shown that trans-acting papB/pefB paralogues can occur outside the context of an adhesin cluster. This plasmid-mediated modification of a bacterial host’s colonization program may optimize horizontal transfer of the mobile element bearing the genes.

scholarly journals A plasmid-encoded papB paralogue modulates autoaggregation of Escherichia coli transconjugants

2020 ◽  
Author(s):  
Ruben Monarrez ◽  
Iruka Okeke
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Genetic Basis ◽  
Mobile Element ◽  
Enteric Bacteria ◽  
Selective Advantage ◽  
Open Reading Frames ◽  
Bacterial Strains ◽  
Element Bearing ◽  
Reading Frames

Abstract Objective: Plasmids are key to the transmission of antimicrobial resistance among enteric bacteria. It is becoming increasingly clear that resistance genes alone do not account for the selective advantage of plasmids and bacterial strains that harbor them. Deletion of a 32 Kb fitness-conferring region of pMB2, a conjugative resistance plasmid, produced a hyper­autoaggregation phenotype in laboratory Escherichia coli. This study sought to determine the genetic basis for hyper-autoaggregation conferred by the pMB2-derived mini-plasmid.Results: The 32 Kb fragment deleted from pMB2 included previously characterized nutrient acquisition genes as well as putative transposase and integrase genes, a 272 bp papB/ pefB-like gene, and several open-reading frames of unknown function. We cloned the papB/ pefB paralogue and found it sufficient to temper the hyper-autoaggregation phenotype. Hyper­autoaggregation conferred by the mini-plasmid did not occur in a fim-negative background. This study has identified and characterized a gene capable of down-regulating host adhesins and has shown that trans-acting papB/pefB paralogues can occur outside the context of an adhesin cluster. This plasmid-mediated modification of a bacterial host’s colonization program may optimize horizontal transfer of the mobile element bearing the genes.

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