scholarly journals Impact of Redox Conditions on Antibiotic Resistance Conjugative Gene Transfer Frequency and Plasmid Fate in Wastewater Ecosystems

2020 ◽  
Vol 54 (23) ◽  
pp. 14984-14993
Author(s):  
Mui-Choo Jong ◽  
Colin R. Harwood ◽  
Adrian Blackburn ◽  
Jason R. Snape ◽  
David W. Graham
Keyword(s):  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Redox Conditions ◽  
Transfer Frequency ◽  
Conjugative Gene Transfer

scholarly journals Horizontally transferred genes in the ctenophore Mnemiopsis leidyi encode enzymes and are expressed during early development

2017 ◽  
Author(s):  
Alexandra M Hernandez ◽  
Joseph F Ryan
Keyword(s):  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Early Development ◽  
Genetic Information ◽  
Mnemiopsis Leidyi ◽  
Uncharacterized Protein ◽  
Phylogenetic Incongruence ◽  
Wide Range ◽  
Growing Body

Horizontal gene transfer has had major impacts on the biology of a wide range of organisms from antibiotic resistance in bacteria to adaptations to herbivory in arthropods. A growing body of literature shows that horizontal gene transfer (HGT) between non-animals and animals is more commonplace than previously thought. In this study, we present a thorough investigation of HGT in the ctenophore Mnemiopsis leidyi. We applied tests of phylogenetic incongruence to identify nine genes that were likely transferred horizontally early in ctenophore evolution from bacteria and non-metazoan eukaryotes. All but one of these HGTs (an uncharacterized protein) appear to perform enzymatic activities in M. leidyi, supporting previous observations that enzymes are more likely to be retained after HGT events. We found that the majority of these nine horizontally transferred genes were expressed during early development, suggesting that they are active and play a role in the biology of M. leidyi. This is the first report of HGT in ctenophores, and contributes to an ever-growing literature on the prevalence of genetic information flowing between non-animals and animals.

scholarly journals CRISPR Interference Limits Horizontal Gene Transfer in Staphylococci by Targeting DNA

Science ◽  
2008 ◽  
Vol 322 (5909) ◽  
pp. 1843-1845 ◽  
Author(s):  
Luciano A. Marraffini ◽  
Erik J. Sontheimer
Keyword(s):  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Staphylococcus Epidermidis ◽  
Pathogenic Bacteria ◽  
Target Sequence ◽  
Crispr Interference ◽  
Multiple Routes ◽  
Short Palindromic Repeat ◽  
Self Splicing

Horizontal gene transfer (HGT) in bacteria and archaea occurs through phage transduction, transformation, or conjugation, and the latter is particularly important for the spread of antibiotic resistance. Clustered, regularly interspaced, short palindromic repeat (CRISPR) loci confer sequence-directed immunity against phages. A clinical isolate ofStaphylococcus epidermidisharbors a CRISPR spacer that matches thenickasegene present in nearly all staphylococcal conjugative plasmids. Here we show that CRISPR interference prevents conjugation and plasmid transformation inS. epidermidis. Insertion of a self-splicing intron intonickaseblocks interference despite the reconstitution of the target sequence in the spliced mRNA, which indicates that the interference machinery targets DNA directly. We conclude that CRISPR loci counteract multiple routes of HGT and can limit the spread of antibiotic resistance in pathogenic bacteria.

scholarly journals Monitoring horizontal antibiotic resistance gene transfer in a colonic fermentation model

2011 ◽  
Vol 78 (2) ◽  
pp. 210-219 ◽  
Author(s):  
Martina C. Haug ◽  
Sabine A. Tanner ◽  
Christophe Lacroix ◽  
Marc J.A. Stevens ◽  
Leo Meile
Keyword(s):  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Resistance Gene ◽  
Antibiotic Resistance Gene ◽  
Colonic Fermentation ◽  
Fermentation Model

Drug Resistance and Gene Transfer Mechanisms in Respiratory/Oral Bacteria

2018 ◽  
Vol 97 (10) ◽  
pp. 1092-1099 ◽  
Author(s):  
S. Jiang ◽  
J. Zeng ◽  
X. Zhou ◽  
Y. Li
Keyword(s):  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Nucleic Acids ◽  
Bacterial Resistance ◽  
Defense Mechanism ◽  
Oral Bacteria ◽  
New Drugs ◽  
Resistant Bacteria ◽  
Oral Microbiota ◽  
Innate Defense

Growing evidence suggests the existence of new antibiotic resistance mechanisms. Recent studies have revealed that quorum-quenching enzymes, such as MacQ, are involved in both antibiotic resistance and cell-cell communication. Furthermore, some small bacterial regulatory RNAs, classified into RNA attenuators and small RNAs, modulate the expression of resistance genes. For example, small RNA sprX, can shape bacterial resistance to glycopeptide antibiotics via specific downregulation of protein SpoVG. Moreover, some bacterial lipocalins capture antibiotics in the extracellular space, contributing to severe multidrug resistance. But this defense mechanism may be influenced by Agr-regulated toxins and liposoluble vitamins. Outer membrane porin proteins and efflux pumps can influence intracellular concentrations of antibiotics. Alterations in target enzymes or antibiotics prevent binding to targets, which act to confer high levels of resistance in respiratory/oral bacteria. As described recently, horizontal gene transfer, including conjugation, transduction and transformation, is common in respiratory/oral microflora. Many conjugative transposons and plasmids discovered to date encode antibiotic resistance proteins and can be transferred from donor bacteria to transient recipient bacteria. New classes of mobile genetic elements are also being identified. For example, nucleic acids that circulate in the bloodstream (circulating nucleic acids) can integrate into the host cell genome by up-regulation of DNA damage and repair pathways. With multidrug resistant bacteria on the rise, new drugs have been developed to combate bacterial antibiotic resistance, such as innate defense regulators, reactive oxygen species and microbial volatile compounds. This review summaries various aspects and mechanisms of antibiotic resistance in the respiratory/oral microbiota. A better understanding of these mechanisms will facilitate minimization of the emergence of antibiotic resistance.

scholarly journals Identification of a Novel Conjugative Plasmid in Mycobacteria That Requires Both Type IV and Type VII Secretion

mBio ◽  
2014 ◽  
Vol 5 (5) ◽  
Author(s):  
Roy Ummels ◽  
Abdallah M. Abdallah ◽  
Vincent Kuiper ◽  
Anouar Aâjoud ◽  
Marion Sparrius ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Antibiotic Resistance Genes ◽  
Conjugative Plasmid ◽  
Content Type ◽  
Conjugative Plasmids ◽  
Type Vii Secretion ◽  
Type Iv ◽  
Slow Growing

ABSTRACTConjugative plasmids have been identified in a wide variety of different bacteria, ranging from proteobacteria to firmicutes, and conjugation is one of the most efficient routes for horizontal gene transfer. The most widespread mechanism of plasmid conjugation relies on different variants of the type IV secretion pathway. Here, we describe the identification of a novel type of conjugative plasmid that seems to be unique for mycobacteria. Interestingly, while this plasmid is efficiently exchanged between different species of slow-growing mycobacteria, includingMycobacterium tuberculosis, it could not be transferred to any of the fast-growing mycobacteria tested. Genetic analysis of the conjugative plasmid showed the presence of a locus containing homologues of three type IV secretion system components and a relaxase. In addition, a new type VII secretion locus was present. Using transposon insertion mutagenesis, we show that in fact both these secretion systems are essential for conjugation, indicating that this plasmid represents a new class of conjugative plasmids requiring two secretion machineries. This plasmid could form a useful new tool to exchange or introduce DNA in slow-growing mycobacteria.IMPORTANCEConjugative plasmids play an important role in horizontal gene transfer between different bacteria and, as such, in their adaptation and evolution. This effect is most obvious in the spread of antibiotic resistance genes. Thus far, conjugation of natural plasmids has been described only rarely for mycobacterial species. In fact, it is generally accepted thatM. tuberculosisdoes not show any recent sign of horizontal gene transfer. In this study, we describe the identification of a new widespread conjugative plasmid that can also be efficiently transferred toM. tuberculosis. This plasmid therefore poses both a threat and an opportunity. The threat is that, through the acquisition of antibiotic resistance markers, this plasmid could start a rapid spread of antibiotic resistance genes between pathogenic mycobacteria. The opportunity is that we could use this plasmid to generate new tools for the efficient introduction of foreign DNA in slow-growing mycobacteria.

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