scholarly journals Conjugative Plasmid Transfer in the Biofilm Formed by Enterococcus faecalis

2006 ◽  
Vol 52 (4) ◽  
pp. 358-367 ◽  
Author(s):  
Takumi Kajiura ◽  
Hideki Wada ◽  
Kenji Ito ◽  
Yojiro Anzai ◽  
Fumio Kato
Keyword(s):  
Enterococcus Faecalis ◽  
Plasmid Transfer ◽  
Conjugative Plasmid ◽  
Conjugative Plasmid Transfer

scholarly journals Enterococcus faecalis Sex Pheromone cCF10 Enhances Conjugative Plasmid Transfer In Vivo

mBio ◽  
2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Helmut Hirt ◽  
Kerryl E. Greenwood-Quaintance ◽  
Melissa J. Karau ◽  
Lisa M. Till ◽  
Purna C. Kashyap ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
High Frequency ◽  
Intestinal Tract ◽  
Bacteriocin Production ◽  
Plasmid Transfer ◽  
Conjugative Plasmid ◽  
Conjugative Plasmid Transfer ◽  
Pheromone Signaling

ABSTRACT Cell-cell communication mediated by peptide pheromones (cCF10 [CF]) is essential for high-frequency plasmid transfer in vitro in Enterococcus faecalis. To examine the role of pheromone signaling in vivo, we established either a CF-producing (CF+) recipient or a recipient producing a biologically inactive variant of CF (CF− recipient) in a germfree mouse model 3 days before donor inoculation and determined transfer frequencies of the pheromone-inducible plasmid pCF10. Plasmid transfer was detected in the upper and middle sections of the intestinal tract 5 h after donor inoculation and was highly efficient in the absence of antibiotic selection. The transconjugant/donor ratio reached a maximum level approaching 1 on day 4 in the upper intestinal tract. Plasmid transfer was significantly lower with the CF− recipient. While rescue of the CF− mating defect by coculture with CF+ recipients is easily accomplished in vitro, no extracellular complementation occurred in vivo. This suggests that most pheromone signaling in the gut occurs between recipient and donor cells in very close proximity. Plasmid-bearing cells (donors plus transconjugants) steadily increased in the population from 0.1% after donor inoculation to about 10% at the conclusion of the experiments. This suggests a selective advantage of pCF10 carriage distinct from antibiotic resistance or bacteriocin production. Our results demonstrate that pheromone signaling is required for efficient pCF10 transfer in vivo. In the absence of CF+ recipients, a low level of transfer to CF− recipients occurred in the gut. This may result from low-level host-mediated induction of the donors in the gastrointestinal (GI) tract, similar to that previously observed in serum. IMPORTANCE Horizontal gene transfer is a major factor in the biology of Enterococcus faecalis, an important nosocomial pathogen. Previous studies showing efficient conjugative plasmid transfer in the gastrointestinal (GI) tracts of experimental animals did not examine how the enterococcal sex pheromone response impacts the efficiency of transfer. Our study demonstrates for the first time pheromone-enhanced, high-frequency plasmid transfer of E. faecalis plasmid pCF10 in a mouse model in the absence of antibiotic or bacteriocin selection. Pheromone production by recipients dramatically increased plasmid transfer in germfree mice colonized initially with recipients, followed by donors. The presence of a coresident community of common gut microbes did not significantly reduce in vivo plasmid transfer between enterococcal donors and recipients. In mice colonized with enterococcal recipients, we detected plasmid transfer in the intestinal tract within 5 h of addition of donors, before transconjugants could be cultured from feces. Surprisingly, pCF10 carriage provided a competitive fitness advantage unrelated to antibiotic resistance or bacteriocin production.

The Enterococcus faecalis Information Gate

2004 ◽  
Author(s):  
Kenichi Wakabayashi ◽  
Masayuki Yamamura
Keyword(s):  
Dna Binding ◽  
Enterococcus Faecalis ◽  
Binding Proteins ◽  
Vibrio Fischeri ◽  
Dna Binding Proteins ◽  
Plasmid Transfer ◽  
Conjugative Plasmid ◽  
Signal Molecules ◽  
Conjugative Plasmid Transfer ◽  
Cellular Computing

Information exchange between cellular compartments allows us to engineer systems based around cooperative principles. In this chapter we consider a unique bacterial communication system, the conjugative plasmid transfer of Enterococcus faecalis. Using these bacteria, we describe how to engineer a logically controlled information gate and build a logical inverter based upon it. Cellular computing is an alternative computing paradigm based on living cells. Microscale organisms, especially bacteria, are well suited for computing for several reasons. A small culture provides an almost limitless supply of bacterial “hardware.” Bacteria can be stored and easily modified by gene recombination. In addition, and important for our purposes, bacteria can produce various signal molecules that are useful for computation. DNA-binding proteins recognize specific regulatory regions of DNA, bind them, and regulate their genetic expression. These proteins are available for use as computing signals inside the cell. Weiss et al. have shown, for example, how to construct logic circuits based on gene expression regulated by DNA-binding proteins. Some signal molecules are associated with intercellular communications between individuals. Intercellular communication is one of the fundamental characteristics of multicellular organisms, but it is also found in single-celled microorganisms, including bacteria. Communication mediated by homoserine lactones can widely be seen in various Gram-negative bacteria. The mechanism of this behavior was well characterized in Vibrio fischeri, due to their bioluminescent activity mediated by homoserine lactones. It has been shown that bacterial information transfer can be engineered as an extension of Escherichia coli into which the lux genes of Vibrio fischeri are transformed. The communication abilities of bacteria therefore allow us to build microbial information processors for cellular computing. Communication mechanisms in Gram-positive bacteria are not yet well understood. One of the exceptions to this is the conjugative plasmid transfer system in Enterococcus faecalis. E. faecalis conjugate in response to a pheromone is released by other cells. Pheromones are seven- or eight-residue amino peptides produced in E. faecalis. In the case of cPD1, the pheromone is produced by truncation of a 22-residue precursor that is the signal peptide of a lipoprotein.

scholarly journals Probiotic Bacillus Affect Enterococcus faecalis Antibiotic Resistance Transfer by Interfering with Pheromone Signaling Cascades

2021 ◽  
Author(s):  
Yu-Chieh Lin ◽  
Eric H.-L. Chen ◽  
Rita P.-Y. Chen ◽  
Gary M. Dunny ◽  
Wei-Shou Hu ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Bacillus Subtilis ◽  
Enterococcus Faecalis ◽  
Plasmid Transfer ◽  
Extracellular Protease ◽  
Conjugative Plasmid ◽  
Fermentation Products ◽  
Conjugative Plasmid Transfer ◽  
Resistance Transfer ◽  
Peptide Pheromone

Enterococcus faecalis, a member of the commensal flora in the human gastrointestinal tract, has become a threatening nosocomial pathogen because it has developed resistance to many known antibiotics. More concerningly, resistance gene-carrying E. faecalis cells may transfer antibiotic resistance to resistance-free E. faecalis cells through their unique quorum sensing-mediated plasmid transfer system. Therefore, we investigated the role of probiotic bacteria in the transfer frequency of the antibiotic resistance plasmid pCF10 in E. faecalis populations to mitigate the spread of antibiotic resistance. Bacillus subtilis natto is a probiotic strain isolated from Japanese fermented soybean foods, and its culture fluid potently inhibited pCF10 transfer by suppressing peptide pheromone activity from cCF10 without inhibiting E. faecalis growth. The inhibitory effect was attributed to at least one 30-50 kDa extracellular protease present in B. subtilis natto. Nattokinase of B. subtilis natto was involved in the inhibition of pCF10 transfer and cleaved cCF10 (LVTLVFV) into “LVTL + VFV” fragments. Moreover, the cleavage product “LVTL” (L peptide) interfered with the conjugative transfer of pCF10. In addition to cCF10, faecalis-cAM373 and gordonii-cAM373, which are mating inducers of vancomycin-resistant E. faecalis, were also cleaved by nattokinase, indicating that B. subtilis natto can likely interfere with vancomycin resistance transfer in E. faecalis. Our work shows the feasibility of applying fermentation products of B. subtilis natto and L peptide to mitigate E. faecalis antibiotic resistance transfer. Importance Enterococcus faecalis is considered a leading cause of hospital-acquired infections. Treatment of these infections has become a major challenge for clinicians because some E. faecalis strains are resistant to multiple clinically used antibiotics. Moreover, antibiotic resistance genes can undergo efficient intra- and interspecies transfer via E. faecalis peptide pheromone-mediated plasmid transfer systems. Therefore, this study provided the first experimental demonstration that probiotics are a feasible approach for interfering with conjugative plasmid transfer between E. faecalis strains to stop the transfer of antibiotic resistance. We found that the extracellular protease(s) of Bacillus subtilis natto cleaved peptide pheromones without affecting the growth of E. faecalis, thereby reducing the frequency of conjugative plasmid transfer. In addition, a specific cleaved pheromone fragment interfered with conjugative plasmid transfer. These findings provide a potential probiotic-based method for interfering with the transfer of antibiotic resistance between E. faecalis strains.

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