Effect of donor-recipient relatedness on the plasmid conjugation frequency: a meta-analysis

Abstract

Background: Conjugation plays a major role in the transmission of plasmids encoding antibiotic resistance genes in both clinical and general settings. The conjugation efficiency is influenced by many biotic and abiotic factors, one of which is the taxonomic relatedness between donor and recipient bacteria. A comprehensive overview of the influence of donor-recipient relatedness on conjugation is still lacking, but such an overview is important to quantitatively assess the risk of plasmid transfer and the effect of interventions which limit the spread of antibiotic resistance, and to obtain parameter values for conjugation in mathematical models. Therefore, we performed a meta-analysis on reported conjugation frequencies from Escherichia coli donors to various recipient species. Results: Thirty-two studies reporting 313 conjugation frequencies for liquid broth matings and 270 conjugation frequencies for filter matings were included in our meta-analysis. The reported conjugation frequencies varied over 11 orders of magnitude. Decreasing taxonomic relatedness between donor and recipient bacteria, when adjusted for confounding factors, was associated with a lower conjugation frequency in liquid matings. The mean conjugation frequency for bacteria of the same order, the same class, and other classes was 10, 20, and 789 times lower than the mean conjugation frequency within the same species, respectively. This association between relatedness and conjugation frequency was not found for filter matings. The conjugation frequency was furthermore found to be influenced by temperature in both types of mating experiments, and in addition by plasmid incompatibility group in liquid matings, and by recipient origin and mating time in filter matings. Conclusions: In our meta-analysis, taxonomic relatedness is limiting conjugation in liquid matings, but not in filter matings, suggesting that taxonomic relatedness is not a limiting factor for conjugation in environments where bacteria are fixed in space.

A highly effective and self-transmissible CRISPR antimicrobial for elimination of target plasmids without antibiotic selection

“…In other words, CRISPR/Cas systems can be used as a weapon for invading into the population in addition to their well-known function in defending against invading plasmid or other mobile genetics elements. Given that CRISPR/Cas have been found on natural plasmids and that over 25% of known plasmids are mobilizable, we expected that CRISPR/Cas could also play an important role in plasmid cooperation and invasion in nature (Alderliesten et al, 2020).…”

Molecular and Functional Characterization of MobK Protein—A Novel-Type Relaxase Involved in Mobilization for Conjugational Transfer of Klebsiella pneumoniae Plasmid pIGRK

“…The experiment was performed according to the procedure described previously [ 27 ]. The mating procedure was performed in liquid medium using E. coli S17-1 [ 49 ] carrying a kanamycin-resistant plasmid (pBGS-oriT [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ] or pRK-1) ( Supplementary Figures S1 and S3 and Table S1 ), as the donor strain and rifampicin-resistant E. coli DH5αR [ 50 ] (as the recipient). In transfer experiments with pBGS-oriT (harboring only oriT sequence without mobK relaxase gene) additional plasmid, pWSK29 [ 51 ] derivatives (pWSK-1/2/3) ( Supplementary Figure S1 and Table S1 ) were used as a MobK (or as MobK mutants) source in donor strain.…”

“…Different mobile genetic elements, like plasmids, integrative and conjugative elements (ICEs) and integrative and mobilizable elements (IMEs), can transfer their genomes via CT from donor to recipient bacterial cell [ 3 ]. A significant consequence of CT is the spreading of antibiotic resistance (AR) among pathogenic bacterial strains [ 4 , 5 , 6 , 7 ]. For these reasons, CT has been widely studied and extensive knowledge about the molecular bases of this process has been gained [ 3 , 8 , 9 , 10 , 11 ].…”

Estimating the rate of plasmid transfer with an adapted Luria–Delbrück fluctuation analysis

“…Pr{ +Δ = } = 1 − ( + + )Δ . [10] The three terms on the right-hand side of equation [9] illustrate the processes enabling the transconjugant population to increase. The first term gives the probability that a donor transforms a recipient into a transconjugant via conjugation ( ).…”

“…al. 9 , used a chemostat to keep the population constant. Other studies shorten the incubation time ̃ such that population growth is negligible and use various laboratory tools to detect the small number of transconjugants time ̃ must occur well before stationary phase is reached to collect proper data for estimating the population growth rate ( = (lñ− ln 0 )/).…”