scholarly journals ARB and ARGs survived from the extremely acidity posing a risk on intestinal bacteria in an in vitro digestion model by horizontal gene transfer

2021 ◽  
Author(s):  
Qiujie Cai ◽  
Yanbin Xu ◽  
Min Zhou ◽  
Ling Yu ◽  
Pengqian Ouyang ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
16S Rrna ◽  
Gastric Juice ◽  
Total Population ◽  
Intestinal Bacteria ◽  
In Vitro Digestion ◽  
Transfer Potential

Abstract Background: Antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) have been considered as emerging contaminants, which even might be closely related to human health.Methods: To investigate the disease-producing risk of ARB and the horizontal gene transfer (HGT) risks of both extracellular ARGs (eARGs) and intracellular ARGs (iARGs), an in vitro digestion model was established to simulate the process of ARB and ARGs going through digestive tract. CTC/DAPI-FCM assay was used to study the survival of ARB during digestion, and the changes of genes (including tetA, tetG, tetM, sul1, sul2, bla EBC, bla FOX, intI1 and 16S rRNA) were determined by QPCR.Results: The results showed that ARB were mostly affected by pH of gastric juice. About 99% ARB (total population of 2.45 × 109–2.54 × 109) were killed by the gastric juice of pH 2.0 for the severely damage of bacterial cell membrane, but more than 80% ARB (total population of 2.71 × 109–3.90 × 109) were still alive with intact cell membrane when the pH of gastric juice increased to 3.0 and above. ARGs, intI1 and 16S rRNA could be detectable even at extreme pH when most bacteria died. The eARGs (accounting for 0.03%–24.56% of total genes) were less than iARGs obviously. The eARGs showed greater HGT potential than that of iARGs, suggesting transformation occurs more easily than conjugation. The transfer potential followed the order as: tet (100%) > sul (75%) > bla (58%), related to the high correlation of intI1 with tetA and sul2 (p < 0.01). Moreover, gastric juice of pH 1.0 could decrease the transfer frequency of ARGs by 2–3 order of magnitude compared to the control, but still threatening human health.Conclusions: Under the treatment of digestive juice, ARGs still have high gene horizontal transfer potential, suggesting that food-borne ARB pose a risk of ARGs horizontal transfer to intestinal bacteria.

scholarly journals IS 1294 Reorganizes Plasmids in a Multidrug-Resistant Escherichia coli Strain

2021 ◽  
Author(s):  
Yushan Pan ◽  
Tengli Zhang ◽  
Lijie Yu ◽  
Zhiyong Zong ◽  
Shiyu Zhao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
16S Rrna ◽  
Multidrug Resistant ◽  
Coli Strain ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
16S Rrna Methylase

The increasing resistance to β-lactams and aminoglycoside antibiotics, mainly due to extended-spectrum β-lactamases (ESBLs) and 16S rRNA methylase genes, is becoming a serious problem in Gram-negative bacteria. Plasmids, as the vehicles for resistance gene capture and horizontal gene transfer, serve a key role in terms of antibiotic resistance emergence and transmission.

scholarly journals Horizontal Gene Transfer and Acquired Antibiotic Resistance in Salmonella enterica Serovar Heidelberg following In Vitro Incubation in Broiler Ceca

2019 ◽  
Vol 85 (22) ◽  
Author(s):  
Adelumola Oladeinde ◽  
Kimberly Cook ◽  
Steven M. Lakin ◽  
Reed Woyda ◽  
Zaid Abdo ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Gastrointestinal Tract ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Gut Microbiome ◽  
Foodborne Pathogen ◽  
Mobile Genetic Elements ◽  
Content Type ◽  
Acquired Antibiotic Resistance

ABSTRACT The chicken gastrointestinal tract harbors microorganisms that play a role in the health and disease status of the host. The cecum is the part of the gut that carries the highest microbial densities, has the longest residence time of digesta, and is a vital site for urea recycling and water regulation. Therefore, the cecum provides a rich environment for bacteria to horizontally transfer genes between one another via mobile genetic elements such as plasmids and bacteriophages. In this study, we used broiler chicken cecum as a model to investigate antibiotic resistance genes that can be transferred in vitro from cecal flora to Salmonella enterica serovar Heidelberg. We used whole-genome sequencing and resistome enrichment to decipher the interactions between S. Heidelberg, the gut microbiome, and acquired antibiotic resistance. After 48 h of incubation of ceca under microaerophilic conditions, we recovered one S. Heidelberg isolate with an acquired IncK2 plasmid (88 kb) carrying an extended-spectrum-β-lactamase gene (blaCMY-2). In vitro, this plasmid was transferable between Escherichia coli and S. Heidelberg strains but transfer was unsuccessful between S. Heidelberg strains. An in-depth genetic characterization of transferred plasmids suggests that they share significant homology with P1-like phages. This study contributes to our understanding of horizontal gene transfer between an important foodborne pathogen and the chicken gut microbiome. IMPORTANCE S. Heidelberg is a clinically important serovar, linked to foodborne illness and among the top 5 serovars isolated from poultry in the United States and Canada. Acquisition of new genetic material from the microbial flora in the gastrointestinal tract of food animals, including broilers, may contribute to increased fitness of pathogens like S. Heidelberg and may increase their level of antibiotic tolerance. Therefore, it is critical to gain a better understanding of the interactions that occur between important pathogens and the commensals present in the animal gut and other agroecosystems. In this report, we show that the native flora in broiler ceca were capable of transferring mobile genetic elements carrying the AmpC β-lactamase (blaCMY-2) gene to an important foodborne pathogen, S. Heidelberg. The potential role for bacteriophage transduction is also discussed.

scholarly journals Trasposon Mediated Horizontal Gene Transfer (T-HGT) of Circulating Tumor DNA Reshapes MM Clonal Architecture

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3065-3065
Author(s):  
Munevver Cinar ◽  
Steven Flygare ◽  
Marina Mosunjac ◽  
Ganji Nagaraju ◽  
Dongkyoo Park ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Drug Sensitivity ◽  
Genetic Material ◽  
Host Cells ◽  
Response To Treatment ◽  
Hierarchical Architecture ◽  
Tumor Evolution ◽  
Sequencing Analysis

Spatial genetic heterogeneity is a characteristic phenomenon that influences multiple myeloma's (MM) phenotype and drug sensitivity (Rasche L. et al and Bolli N et al.). Hence, the branch model of tumor evolution is not sufficient to explain the disorganized architecture observed in MM. In this study, we investigated whether MM ctDNA horizontal gene transfer (HGT) affect tumor genetic architecture and drug sensitivity, resembling what is seen in prokaryotes, and elucidated the mechanisms involved in the mobilization of genetic material from one cell to another. We identified that plasma from patients with MM transmits drug sensitivity or resistance to cells in culture. This transmission of drug sensitivity is mediated by ctDNA transfer of oncogenes to a host cell. Importantly, in vitro and in vivo demonstrated that ctDNA mainly targets cells resembling the cell of origin (tropism). Karyotype spreads and whole genome sequencing demonstrated that once patients ctDNA encounters host cells, it migrates into the nucleus where it ultimately integrates into the cell's genome. Integration to the genome was confirmed to be targeted to myeloma cells. Further sequencing analysis of multiple MM samples identified ctDNA tropism and integration is dependent on the 5' and 3' end presence of transposable elements (TE), particularly of the MIR and ALUsq family. These results were further validated by TE mediated delivery of GFP into MM cells in vitro and HSVTK in tumors of mouse xenografts. In conclusion, this data indicates for the first time that TE mediates MM ctDNA HGT into homologous tumor cells shaping the hierarchical architecture of tumor clones and affecting tumor response to treatment. Therapeutically, this unique quality of ctDNA can be exploited for targeted gene therapeutic approaches in MM and potentially other cancers. Disclosures Bernal-Mizrachi: Kodikas Therapeutic Solutions, Inc: Equity Ownership; TAKEDA: Research Funding; Winship Cancer Institute: Employment, Patents & Royalties.

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 How environment shapes horizontal gene transfer

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Rama Bhatia ◽  
Hande Kirit ◽  
Jonathan Bollback
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Gene Dosage ◽  
Recipient Cell ◽  
Endogenous Gene ◽  
Fitness Effects ◽  
Serovar Typhimurium ◽  
A Cell ◽  
Evolutionary Fate

The evolutionary fate of a horizontal gene transfer (HGT) event is determined by its fitness on the recipient cell, i.e., whether it is beneficial, neutral or deleterious. The distribution of fitness effects (DFE), thus is a fundamental predictor of the outcome of an HGT event. The environment plays a considerable role in determining the fitness cost of a horizontally transferred gene. We have studied the fitness effects of genes transferred from Salmonella enterica serovar Typhimurium to Escherichia coli in six environments, that potentially represent the conditions experienced by the two species. The data suggests high variability of genes in different environments. Genes, whose fitness varies substantially between environments, may be able to persist in populations while being deleterious in one environment, they may be neutral or even beneficial in another environment, suggesting that environmental fluctuations may increase the likelihood of HGT. In addition to the in vitro environments, we are also looking at, how changes in the intrinsic environment of a cell, after an HGT event, could affect fitness. An increase in protein dosage due to functional similarity of the horizontally transferred gene to the endogenous gene can cause an imbalance in the cell, thereby leading to a negative fitness effect. By comparing the growth rates of each ortholog gene with the wild type strain, we can elucidate when gene dosage acts as a barrier to HGT.

scholarly journals Minimal and RNA-free RNase P in Aquifex aeolicus

2017 ◽  
Vol 114 (42) ◽  
pp. 11121-11126 ◽  
Author(s):  
Astrid I. Nickel ◽  
Nadine B. Wäber ◽  
Markus Gößringer ◽  
Marcus Lechner ◽  
Uwe Linne ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Rnase P ◽  
Aquifex Aeolicus ◽  
Trna Processing ◽  
Hyperthermophilic Bacterium ◽  
Domains Of Life

RNase P is an essential tRNA-processing enzyme in all domains of life. We identified an unknown type of protein-only RNase P in the hyperthermophilic bacterium Aquifex aeolicus: Without an RNA subunit and the smallest of its kind, the 23-kDa polypeptide comprises a metallonuclease domain only. The protein has RNase P activity in vitro and rescued the growth of Escherichia coli and Saccharomyces cerevisiae strains with inactivations of their more complex and larger endogenous ribonucleoprotein RNase P. Homologs of Aquifex RNase P (HARP) were identified in many Archaea and some Bacteria, of which all Archaea and most Bacteria also encode an RNA-based RNase P; activity of both RNase P forms from the same bacterium or archaeon could be verified in two selected cases. Bioinformatic analyses suggest that A. aeolicus and related Aquificaceae likely acquired HARP by horizontal gene transfer from an archaeon.

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.

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