scholarly journals Novel mechanism of plasmid-DNA transfer mediated by heterologous cell fusion in syntrophic coculture of Clostridium organisms

2021 ◽  
Author(s):  
Kamil Charubin ◽  
Gwendolyn J Gregory ◽  
ELEFTHERIOS TERRY PAPOUTSAKIS

The evolution of bacteria is driven by random genetic mutations and horizontal gene transfer (HGT) of genetic material from other bacteria. HGT can occur via transformation, transduction, and conjugation. Here, we present a potential new mechanism of HGT which occurs in a syntrophic Clostridium coculture. We have previously shown that in syntrophic cocultures of Clostridium acetobutylicum and Clostridium ljungdahlii, the two organisms undergo heterologous cell fusion, which includes fusion of the peptidoglycan cell walls and membranes. Heterologous cell fusion facilitated a large-scale exchange of cytoplasmic protein and RNA between the two organisms, leading to the formation of hybrid bacterial cells containing cytoplasmic material of the two parent organisms. Here we present new evidence that cell fusion events also facilitate the exchange of plasmid DNA between the two organisms of the syntrophic coculture. Through the use of a selective subculturing process, we successfully isolated wild-type C. acetobutylicum clones which have acquired a portion of the plasmid DNA, containing the antibiotic resistance marker, from a recombinant strain of C. ljungdahlii. Fusion events led to formation of persistent aberrant hybrid cells with distinct morphogenetic characteristics. Furthermore, our data support the concept of a novel, interspecies, mechanism of acquiring antibiotic resistance. Since neither organism contains any known conjugation machinery or mechanism, these findings expand our understanding of multi-species microbiomes, their survival strategies, and evolution.

1970 ◽  
pp. 66-70
Author(s):  
Sitaram Aryal

Bacterial resistance to antibiotics occurs even without the use of antibiotics. Antibiotic use exerts a selective pressure to the bacterial flora that help in the emergence and development of antibiotic resistance. Antibiotics are used worldwide both in veterinary and human medicine. The wide spread use of antibiotics in human and animal has raised the concern about the development of resistant and multi resistant bacteria that possess a potential danger to animals and men, as resistance may cause treatment failure. Resistance may be natural or acquired. Acquired resistance is due to transfer of extrachromosomal genetic material (R-plasmids) and is very important. The R-plasmids are spread to other bacterial cells by transformation, transduction, conjugation and transposition. Transmitted antibiotic resistance in disease causing bacteria may cause zoonotic infections and resistant non-infectious bacteria may serve as a reservoir of R- plasmids for the pathogenic organism(s). This paper highlights the mechanism of development of resistance in bacteria and means to minimize it.Key words: Antibiotic resistance; Bacteria; Extrachromosomal material; Resistance; R-plasmidsDOI: http://dx.doi.org/10.3126/narj.v4i0.4873Nepal Agriculture Research Journal Vol. 4&5, 2001/2002Page: 66-70Uploaded date: 9 June, 2011


mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Kamil Charubin ◽  
Shannon Modla ◽  
Jeffrey L. Caplan ◽  
Eleftherios Terry Papoutsakis

ABSTRACT Microbial syntrophy is universal in nature, profoundly affecting the composition and function of microbiomes. We have recently reported data suggesting direct cell-to-cell interactions leading to electron and material exchange between the two microbes in the syntrophy between Clostridium ljungdahlii and C. acetobutylicum. Here, transmission electron microscopy and electron tomography demonstrated cell wall and membrane fusions between the two organisms, whereby C. ljungdahlii appears to invade C. acetobutylicum pole to pole. Correlative fluorescence transmission electron microscopy demonstrated large-scale exchange of proteins. Flow cytometry analysis captured the extent and dynamic persistence of these interactions. Dividing hybrid cells were identified containing stained proteins from both organisms, thus demonstrating persistence of cells with exchanged cellular components. Fluorescence microscopy and flow cytometry of one species with stained RNA and the other tagged with a fluorescent protein demonstrated extensive RNA exchange and identified hybrid cells, some of which continued to divide, while some were in an advanced C. acetobutylicum sporulation form. These data demonstrate that cell fusion enables large-scale cellular material exchange between the two organisms. Although unanticipated and never previously reported, these phenomena are likely widely distributed in nature, have profound implications for species evolution and the function of microbial communities, and could find utility in biotechnology. They may shed new light onto little-understood phenomena, such as antibiotic heteroresistance of pathogens, pathogen invasion of human tissues, and the evolutionary trajectory and persistence of unculturable bacteria. IMPORTANCE We report that two different bacterial organisms engage in heterologous cell fusion that leads to massive exchange of cellular material, including proteins and RNA, and the formation of persistent hybrid cells. The interspecies cell fusion observed here involves a syntrophic microbial system, but these heterologous cell fusions were observed even under nonstrict syntrophic conditions, leaving open the possibility that strict syntrophy may not be necessary for interspecies cell fusion and cellular material exchange. Formation of hybrid cells that contain proteins and RNA from both organisms is unexpected and unprecedented. Such fusion events are likely widely distributed in nature, but have gone undetected. The implications are profound and may shed light onto many unexplained phenomena in human health, natural environments, evolutionary biology, and biotechnology.


2020 ◽  
Vol 91 (6) ◽  
pp. AB591-AB592
Author(s):  
Ratha-Korn Vilaichone ◽  
Natsuda Aumpan ◽  
Tomohisa Uchida ◽  
Thawee Ratanachu-ek ◽  
Lotay Tshering ◽  
...  

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 874
Author(s):  
Periyasamy Sivalingam ◽  
John Poté ◽  
Kandasamy Prabakar

Over the past decades, the rising antibiotic resistance bacteria (ARB) are continuing to emerge as a global threat due to potential public health risk. Rapidly evolving antibiotic resistance and its persistence in the environment, have underpinned the need for more studies to identify the possible sources and limit the spread. In this context, not commonly studied and a neglected genetic material called extracellular DNA (eDNA) is gaining increased attention as it can be one of the significant drivers for transmission of extracellular ARGS (eARGs) via horizontal gene transfer (HGT) to competent environmental bacteria and diverse sources of antibiotic-resistance genes (ARGs) in the environment. Consequently, this review highlights the studies that address the environmental occurrence of eDNA and encoding eARGs and its impact on the environmental resistome. In this review, we also brief the recent dedicated technological advancements that are accelerating extraction of eDNA and the efficiency of treatment technologies in reducing eDNA that focuses on environmental antibiotic resistance and potential ecological health risk.


2020 ◽  
Vol 44 (46) ◽  
pp. 20334-20340
Author(s):  
Han Gao ◽  
Ying Ge ◽  
Min-Hao Jiang ◽  
Cheng Chen ◽  
Le-Yun Sun ◽  
...  

Antibiotic resistance mediated by β-lactamases including metallo-β-lactamases (MβLs) has become an emerging threat.


2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Martin Johnsson ◽  
Andrew Whalen ◽  
Roger Ros-Freixedes ◽  
Gregor Gorjanc ◽  
Ching-Yi Chen ◽  
...  

Abstract Background Meiotic recombination results in the exchange of genetic material between homologous chromosomes. Recombination rate varies between different parts of the genome, between individuals, and is influenced by genetics. In this paper, we assessed the genetic variation in recombination rate along the genome and between individuals in the pig using multilocus iterative peeling on 150,000 individuals across nine genotyped pedigrees. We used these data to estimate the heritability of recombination and perform a genome-wide association study of recombination in the pig. Results Our results confirmed known features of the recombination landscape of the pig genome, including differences in genetic length of chromosomes and marked sex differences. The recombination landscape was repeatable between lines, but at the same time, there were differences in average autosome-wide recombination rate between lines. The heritability of autosome-wide recombination rate was low but not zero (on average 0.07 for females and 0.05 for males). We found six genomic regions that are associated with recombination rate, among which five harbour known candidate genes involved in recombination: RNF212, SHOC1, SYCP2, MSH4 and HFM1. Conclusions Our results on the variation in recombination rate in the pig genome agree with those reported for other vertebrates, with a low but nonzero heritability, and the identification of a major quantitative trait locus for recombination rate that is homologous to that detected in several other species. This work also highlights the utility of using large-scale livestock data to understand biological processes.


2021 ◽  
Vol 2021 (11) ◽  
pp. pdb.prot101212 ◽  
Author(s):  
Michael R. Green ◽  
Joseph Sambrook

This protocol describes a convenient method for the preparation, use, and storage of competent Escherichia coli. The reported transformation efficiency of this method is ∼5 × 107 transformants/µg of plasmid DNA.


Sign in / Sign up

Export Citation Format

Share Document