scholarly journals Draft Genome of Shewanella frigidimarina Ag06-30, a Marine Bacterium Isolated from Potter Peninsula, King George Island, Antarctica

2016 ◽  
Vol 4 (3) ◽  
Author(s):  
Gisela Parmeciano Di Noto ◽  
Susana C. Vázquez ◽  
Walter P. MacCormack ◽  
Andrés Iriarte ◽  
Cecilia Quiroga
Keyword(s):  
Gene Transfer ◽  
Lateral Gene Transfer ◽  
Marine Bacterium ◽  
Draft Genome ◽  
Mobile Genetic Elements ◽  
King George Island ◽  
Genetic Elements ◽  
Shewanella Frigidimarina ◽  
Insight Into ◽  
Potter Peninsula

We present the draft genome of Shewanella frigidimarina Ag06-30, a marine bacterium from King George Island, Antarctica, which encodes the carbapenemase SFP-1. The assembly contains 4,799,218 bp (G+C content 41.24%). This strain harbors several mobile genetic elements that provide insight into lateral gene transfer and bacterial plasticity and evolution.

scholarly journals MECHANISMS OF RESISTANCE TRANSFER IN BACTERIA

2010 ◽  
Vol 3 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Maja Velhner ◽  
Jelena Petrović ◽  
Igor Stojanov ◽  
Radomir Ratajac ◽  
Dragica Stojanović
Keyword(s):  
Gene Transfer ◽  
Lateral Gene Transfer ◽  
Genomic Structure ◽  
Genetic Material ◽  
Mobile Genetic Elements ◽  
Mechanisms Of Resistance ◽  
Genetic Elements ◽  
Resistance Transfer ◽  
The Future ◽  
Microbial Infections

Wide application of antimicorbial agents forces bacteria to utilize specific genes and rearrange genomic structure in order to survive in the environment. In this article lateral gene transfer, mobile genetic elements, plasmid mediated resistance and spontaneous mutators in bacteria are briefly described. This resourceful means, by which microorganisms manage to communicate and transfer genetic material in their own kingdom, raises concerns about the possibility to keep microbial infections under control in the future.

scholarly journals A mobile genetic element increases bacterial host fitness by manipulating development

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Joshua M Jones ◽  
Ilana Grinberg ◽  
Avigdor Eldar ◽  
Alan D Grossman
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Mobile Genetic Elements ◽  
Selective Advantage ◽  
Host Cells ◽  
Bacterial Host ◽  
Host Fitness ◽  
Genetic Elements ◽  
Necessary And Sufficient ◽  
Integrative And Conjugative Element

Horizontal gene transfer is a major force in bacterial evolution. Mobile genetic elements are responsible for much of horizontal gene transfer and also carry beneficial cargo genes. Uncovering strategies used by mobile genetic elements to benefit host cells is crucial for understanding their stability and spread in populations. We describe a benefit that ICEBs1, an integrative and conjugative element of Bacillus subtilis, provides to its host cells. Activation of ICEBs1 conferred a frequency-dependent selective advantage to host cells during two different developmental processes: biofilm formation and sporulation. These benefits were due to inhibition of biofilm-associated gene expression and delayed sporulation by ICEBs1-containing cells, enabling them to exploit their neighbors and grow more prior to development. A single ICEBs1 gene, devI (formerly ydcO), was both necessary and sufficient for inhibition of development. Manipulation of host developmental programs allows ICEBs1 to increase host fitness, thereby increasing propagation of the element.

scholarly journals Disabling a Type I-E CRISPR-Cas Nuclease with a Bacteriophage-Encoded Anti-CRISPR Protein

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
April Pawluk ◽  
Megha Shah ◽  
Marios Mejdani ◽  
Charles Calmettes ◽  
Trevor F. Moraes ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Transcriptional Repressor ◽  
Mobile Genetic Elements ◽  
Type I ◽  
Genetic Studies ◽  
Genetic Elements ◽  
Crispr System ◽  
Mechanistic Insight ◽  
Resistance To Invasion ◽  
Insight Into

ABSTRACT CRISPR (clustered regularly interspaced short palindromic repeat)-Cas adaptive immune systems are prevalent defense mechanisms in bacteria and archaea. They provide sequence-specific detection and neutralization of foreign nucleic acids such as bacteriophages and plasmids. One mechanism by which phages and other mobile genetic elements are able to overcome the CRISPR-Cas system is through the expression of anti-CRISPR proteins. Over 20 different families of anti-CRISPR proteins have been described, each of which inhibits a particular type of CRISPR-Cas system. In this work, we determined the structure of type I-E anti-CRISPR protein AcrE1 by X-ray crystallography. We show that AcrE1 binds to the CRISPR-associated helicase/nuclease Cas3 and that the C-terminal region of the anti-CRISPR protein is important for its inhibitory activity. We further show that AcrE1 can convert the endogenous type I-E CRISPR system into a programmable transcriptional repressor. IMPORTANCE The CRISPR-Cas immune system provides bacteria with resistance to invasion by potentially harmful viruses, plasmids, and other foreign mobile genetic elements. This study presents the first structural and mechanistic insight into a phage-encoded protein that inactivates the type I-E CRISPR-Cas system in Pseudomonas aeruginosa. The interaction of this anti-CRISPR protein with the CRISPR-associated helicase/nuclease proteins Cas3 shuts down the CRISPR-Cas system and protects phages carrying this gene from destruction. This interaction also allows the repurposing of the endogenous type I-E CRISPR system into a programmable transcriptional repressor, providing a new biotechnological tool for genetic studies of bacteria encoding this type I-E CRISPR-Cas system. IMPORTANCE The CRISPR-Cas immune system provides bacteria with resistance to invasion by potentially harmful viruses, plasmids, and other foreign mobile genetic elements. This study presents the first structural and mechanistic insight into a phage-encoded protein that inactivates the type I-E CRISPR-Cas system in Pseudomonas aeruginosa. The interaction of this anti-CRISPR protein with the CRISPR-associated helicase/nuclease proteins Cas3 shuts down the CRISPR-Cas system and protects phages carrying this gene from destruction. This interaction also allows the repurposing of the endogenous type I-E CRISPR system into a programmable transcriptional repressor, providing a new biotechnological tool for genetic studies of bacteria encoding this type I-E CRISPR-Cas system.

scholarly journals Disentangling the effects of selection and loss bias on gene dynamics

2017 ◽  
Author(s):  
Jaime Iranzo ◽  
José A. Cuesta ◽  
Susanna Manrubia ◽  
Mikhail I. Katsnelson ◽  
Eugene V. Koonin
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Genome Size ◽  
Mobile Genetic Elements ◽  
Loss Ratio ◽  
Effective Population ◽  
Strong Selection ◽  
Genetic Elements ◽  
Defense Systems ◽  
Parasite Defense

ABSTRACTWe combine mathematical modelling of genome evolution with comparative analysis of prokaryotic genomes to estimate the relative contributions of selection and intrinsic loss bias to the evolution of different functional classes of genes and mobile genetic elements (MGE). An exact solution for the dynamics of gene family size was obtained under a linear duplication-transfer-loss model with selection. With the exception of genes involved in information processing, particularly translation, which are maintained by strong selection, the average selection coefficient for most non-parasitic genes is low albeit positive, compatible with the observed positive correlation between genome size and effective population size. Free-living microbes evolve under stronger selection for gene retention than parasites. Different classes of MGE show a broad range of fitness effects, from the nearly neutral transposons to prophages, which are actively eliminated by selection. Genes involved in anti-parasite defense, on average, incur a fitness cost to the host that is at least as high as the cost of plasmids. This cost is probably due to the adverse effects of autoimmunity and curtailment of horizontal gene transfer caused by the defense systems and selfish behavior of some of these systems, such as toxin-antitoxin and restriction-modification modules. Transposons follow a biphasic dynamics, with bursts of gene proliferation followed by decay in the copy number that is quantitatively captured by the model. The horizontal gene transfer to loss ratio, but not the duplication to loss ratio, correlates with genome size, potentially explaining the increased abundance of neutral and costly elements in larger genomes.SIGNIFICANCEEvolution of microbes is dominated by horizontal gene transfer and the incessant host-parasite arms race that promotes the evolution of diverse anti-parasite defense systems. The evolutionary factors governing these processes are complex and difficult to disentangle but the rapidly growing genome databases provide ample material for testing evolutionary models. Rigorous mathematical modeling of evolutionary processes, combined with computer simulation and comparative genomics, allowed us to elucidate the evolutionary regimes of different classes of microbial genes. Only genes involved in key informational and metabolic pathways are subject to strong selection whereas most of the others are effectively neutral or even burdensome. Mobile genetic elements and defense systems are costly, supporting the understanding that their evolution is governed by the same factors.

scholarly journals Draft Genome Sequences of 14 Staphylococcus aureus Sequence Type 5 Isolates from California, USA

2017 ◽  
Vol 5 (13) ◽  
Author(s):  
Samantha J. Hau ◽  
Darrell O. Bayles ◽  
David P. Alt ◽  
Tracy L. Nicholson
Keyword(s):  
Staphylococcus Aureus ◽  
Draft Genome ◽  
Mobile Genetic Elements ◽  
Sequence Type ◽  
Genome Sequences ◽  
Content Type ◽  
Genetic Elements

ABSTRACT Staphylococcus aureus is part of the human epithelial microbiota; however, it is also a pathogen. The acquisition of mobile genetic elements plays a role in the virulence of S. aureus isolates and contributes to treatment failures. This report details the draft genome sequences of 14 clinical S. aureus isolates.

scholarly journals Role of Horizontal Gene Transfer in the Development of Multidrug Resistance in Haemophilus influenzae

mSphere ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Kristin Hegstad ◽  
Haima Mylvaganam ◽  
Jessin Janice ◽  
Ellen Josefsen ◽  
Audun Sivertsen ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Haemophilus Influenzae ◽  
Resistance Genes ◽  
Mobile Genetic Elements ◽  
Beta Lactam ◽  
Content Type ◽  
Genetic Elements ◽  
Wide Range ◽  
Chromosomal Genes

ABSTRACT Haemophilus influenzae colonizes the respiratory tract in humans and causes both invasive and noninvasive infections. Resistance to extended-spectrum cephalosporins in H. influenzae is rare in Europe. In this study, we defined acquired resistance gene loci and ftsI mutations in multidrug-resistant (MDR) and/or PBP3-mediated beta-lactam-resistant (rPBP3) H. influenzae strains, intending to understand the mode of spread of antibiotic resistance determinants in this species. Horizontal transfer of mobile genetic elements and transformation with resistance-conferring ftsI alleles were contributory. We found one small plasmid and three novel integrative conjugative elements (ICEs) which carry different combinations of resistance genes. Demonstration of transfer and/or ICE circular forms showed that the ICEs are functional. Two extensively MDR genetically unrelated H. influenzae strains (F and G) from the same geographical region shared an identical novel MDR ICE (Tn6686) harboring blaTEM-1, catA2-like, and tet(B). The first Nordic case of MDR H. influenzae septicemia, strain 0, originating from the same geographical area as these strains, had a similar resistance pattern but contained another ICE [Tn6687 with blaTEM-1, catP and tet(B)] with an overall structure quite similar to that of Tn6686. Comparison of the complete ftsI genes among rPBP3 strains revealed that the entire gene or certain regions of it are identical in genetically unrelated strains, indicating horizontal gene transfer. Our findings illustrate that H. influenzae is capable of acquiring resistance against a wide range of commonly used antibiotics through horizontal gene transfer, in terms of conjugative transfer of ICEs and transformation of chromosomal genes. IMPORTANCE Haemophilus influenzae colonizes the respiratory tract in humans and causes both invasive and noninvasive infections. As a threat to treatment, resistance against critically important antibiotics is on the rise in H. influenzae. Identifying mechanisms for horizontal acquisition of resistance genes is important to understand how multidrug resistance develops. The present study explores the antimicrobial resistance genes and their context in beta-lactam-resistant H. influenzae with coresistance to up to four non-beta-lactam groups. The results reveal that this organism is capable of acquiring resistance to a wide range of commonly used antibiotics through conjugative transfer of mobile genetic elements and transformation of chromosomal genes, resulting in mosaic genes with a broader resistance spectrum. Strains with chromosomally mediated resistance to extended-spectrum cephalosporins, co-trimoxazole, and quinolones combined with mobile genetic elements carrying genes mediating resistance to ampicillin, tetracyclines, and chloramphenicol have been reported, and further dissemination of such strains represents a particular concern.

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