scholarly journals Origin-of-transfer sequences facilitate mobilisation of non-conjugative antimicrobial-resistance plasmids inStaphylococcus aureus

2015 ◽  
Vol 43 (16) ◽  
pp. 7971-7983 ◽  
Author(s):  
Frances G. O'Brien ◽  
Karina Yui Eto ◽  
Riley J. T. Murphy ◽  
Heather M. Fairhurst ◽  
Geoffrey W. Coombs ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Plasmids ◽  
Origin Of Transfer

scholarly journals The characterization of ESBL genes in Escherichia coli and Klebsiella pneumoniae causing nosocomial infections in Vietnam

2013 ◽  
Vol 7 (12) ◽  
pp. 922-928 ◽  
Author(s):  
Nguyen Hoang Thu Trang ◽  
Tran Vu Thieu Nga ◽  
James I Campbell ◽  
Nguyen Trong Hiep ◽  
Jeremy Farrar ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Nosocomial Infections ◽  
Enteric Bacteria ◽  
E Coli ◽  
Plasmid Analysis ◽  
Resistance Plasmids ◽  
Genes Encoding ◽  
Third Generation Cephalosporins

Background: Extended-spectrum β-lactamases (ESBLs) are enzymes capable of hydrolyzing oxyimino-β-lactams and inducing resistance to third generation cephalosporins. The genes encoding ESBLs are widespread and generally located on highly transmissible resistance plasmids. We aimed to investigate the complement of ESBL genes in E. coli and Klebsiella pneumoniae causing nosocomial infections in hospitals in Ho Chi Minh City, Vietnam. Methodology: Thirty-two non-duplicate isolates of E. coli and Klebsiella pneumoniae causing nosocomial infections, isolated between March and June 2010, were subjected to antimicrobial susceptibility testing. All isolates were PCR-amplified to detect the blaSHV, blaTEM and blaCTX-M ESBL genes and subjected to plasmid analysis. Results: We found that co-resistance to multiple antimicrobials was highly prevalent, and we report the predominance of the blaCTX-M-15 and blaCTX-M-27 genes, located on highly transmissible plasmids ranging from 50 to 170 kb in size. Conclusions: Our study represents a snap shot of ESBL-producing enteric bacteria causing nosocomial infections in this setting. We suggest that antimicrobial resistance in nosocomial E. coli and Klebsiella pneumoniae is rampant in Vietnam and ESBL organisms are widespread. In view of these data and the dramatic levels of antimicrobial resistance reported in Vietnam we advocate an urgent review of antimicrobial use in the Vietnamese healthcare system.

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 Clinically Relevant Plasmid-Host Interactions Indicate that Transcriptional and Not Genomic Modifications Ameliorate Fitness Costs of Klebsiella pneumoniae Carbapenemase-Carrying Plasmids

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Michelle M. C. Buckner ◽  
Howard T. H. Saw ◽  
Rachael N. Osagie ◽  
Alan McNally ◽  
Vito Ricci ◽  
...  
Keyword(s):  
Gene Expression ◽  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Selection Pressure ◽  
Natural Host ◽  
Fitness Costs ◽  
Content Type ◽  
Resistance Plasmids ◽  
The Impact ◽  
Plasmid Carriage

ABSTRACT The rapid dissemination of antimicrobial resistance (AMR) around the globe is largely due to mobile genetic elements, such as plasmids. They confer resistance to critically important drugs, including extended-spectrum beta-lactams, carbapenems, and colistin. Large, complex resistance plasmids have evolved alongside their host bacteria. However, much of the research on plasmid-host evolution has focused on small, simple laboratory plasmids in laboratory-adapted bacterial hosts. These and other studies have documented mutations in both host and plasmid genes which occur after plasmid introduction to ameliorate fitness costs of plasmid carriage. We describe here the impact of two naturally occurring variants of a large AMR plasmid (pKpQIL) on a globally successful pathogen. In our study, after pKpQIL plasmid introduction, no changes in coding domain sequences were observed in their natural host, Klebsiella pneumoniae . However, significant changes in chromosomal and plasmid gene expression may have allowed the bacterium to adapt to the acquisition of the AMR plasmid. We hypothesize that this was sufficient to ameliorate the associated fitness costs of plasmid carriage, as pKpQIL plasmids were maintained without selection pressure. The dogma that removal of selection pressure (e.g., antimicrobial exposure) results in plasmid loss due to bacterial fitness costs is not true for all plasmid/host combinations. We also show that pKpQIL impacted the ability of K. pneumoniae to form a biofilm, an important aspect of virulence. This study used highly relevant models to study the interaction between AMR plasmids and pathogens and revealed striking differences from results of studies done on laboratory-adapted plasmids and strains. IMPORTANCE Antimicrobial resistance is a serious problem facing society. Many of the genes that confer resistance can be shared between bacteria through mobile genetic elements, such as plasmids. Our work shows that when two clinically relevant AMR plasmids enter their natural host bacteria, there are changes in gene expression, rather than changes to gene coding sequences. These changes in gene expression ameliorate the potential fitness costs of carriage of these AMR plasmids. In line with this, the plasmids were stable within their natural host and were not lost in the absence of selective pressure. We also show that better understanding of the impact of resistance plasmids on fundamental pathogen biology, including biofilm formation, is crucial for fighting drug-resistant infections.

Effects of two simulated oxytetracycline dosing regimens on horizontal transfer of antimicrobial resistance plasmids in an in vitro pharmacodynamic model

2011 ◽  
Vol 72 (7) ◽  
pp. 877-883 ◽  
Author(s):  
Brian V. Lubbers ◽  
Greg J. Peterson ◽  
Sanjeev K. Narayanan ◽  
James A. Havel ◽  
Johann F. Coetzee ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Horizontal Transfer ◽  
Pharmacodynamic Model ◽  
Resistance Plasmids ◽  
Dosing Regimens

scholarly journals Molecular Antimicrobial Resistance ofNeisseria gonorrhoeaein a Moroccan Area

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Safae Karim ◽  
Chahrazed Bouchikhi ◽  
Abdelaziz Banani ◽  
Hinde El Fatemi ◽  
Tiatou Souho ◽  
...  
Keyword(s):  
Risk Factors ◽  
Antimicrobial Resistance ◽  
Tetracycline Resistance ◽  
Molecular Profile ◽  
Molecular Tools ◽  
Related Risk ◽  
Resistance Plasmids ◽  
Resistance To Penicillin ◽  
Ciprofloxacin Resistance

Objectives. To identify the prevalence and the types ofNeisseria gonorrhoeae(NG) resistance plasmids-mediated penicillin (PPNG) and tetracycline (TRNG), the ciprofloxacin resistance (CRNG), and related risk factors of each types of resistance.Methods. The beta-lactamase-producing plasmid types (Africa, Asia, and Toronto),tetMtetracycline resistance plasmid types (America and Dutch), and the determination of the Ser-91 mutation of GyrA were detected by specifics PCRs on 149 diagnosed NG positives samples followed byHinf1digestion fortetMandgyrAmutation.Results. 135 (90.1%) samples showed a profile of molecular resistance to at least one antibiotic with predominance of ciprofloxacin resistance. In fact, 36 (24.2%) and 69 (46.3%) cases harbored PPNG and TRNG, respectively, and 116 (77.9%) cases showed the mutation Ser-91 of GyrA (CRNG). From a total of 36 PPNG isolates, the Toronto, Asian, and Toronto/Asian types were detected in 13 (36.1%), 10 (27.8%), and 13 (36.1%) cases, respectively, whereas the African type was not detected. In addition, the American type of TRNG was detected in 92.8% (64/69) of cases, while the Dutch type was detected in 7.2% (5/69) of cases. The association of demographics and clinical variables with NG resistance to ciprofloxacin, penicillin, and tetracycline was studied and the risk factors have been determined.Conclusion. Resistance to penicillin, tetracycline, and ciprofloxacin among NG samples positives remained at high levels in Morocco as determined by molecular profile. So, the use of molecular tools for NG antimicrobial resistance detection can help in the management and spread limitation of this infection.

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