MedicalResearch.com Interview with:
Dr. Lingchong You PhD
Paul Ruffin Scarborough Associate Professor of Engineering
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. You: Horizontal gene transfer (HGT) refers to the transfer of genes between organisms of the same or different species other than reproduction. In bacteria, Horizontal gene transfer can occur through conjugation (bacterial mating), transduction mediated by phage, or transformation. During conjugation, a donor cell makes a copy of a conjugal plasmid and passes it to a recipient cell, turning it into a transconjugant.
It is well appreciated that HGT (particularly through conjugation) is the major mechanism underlying the wide spread of genes encoding antibiotic resistance. Given this notion, it is tempting to assume that the use of antibiotics could increase the efficiency of horizontal gene transfer, creating a vicious cycle. Indeed, this has been speculated in the literature even though precise experimental measurements have been lacking.
In our study, we find that antibiotics covering all major classes do not promote the probability of conjugation between donor and recipient cells. Instead, antibiotics modulate the final outcome of conjugation dynamics by imposing different degrees of selection on the donor cells, recipient cells, and the transconjugants. Depending on the antibiotic doses and how the antibiotic affects the three populations, the selection dynamics could lead to an increase or the decrease in the frequency of transconjugants.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. You: From the medical perspective, a major take-home message is the importance of the antibiotic dosing protocols. Certain antibiotic dosing protocols are more likely to promote spread of transconjugants (through modulation of population dynamics) than others.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. You: Related to the previous point, precise measurements of the rate of horizontal gene transfer and understanding how antibiotics affect the growth and death of individual populations are critical for effective design of antibiotic treatment protocols that can effectively inhibit pathogen survival without promoting spread of antibiotic resistance through HGT. These are the focus of our ongoing work in this area.
MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.
“Antibiotics as a selective driver for conjugation dynamics,” Allison J. Lopatkin, Shuqiang Huang, Robert P. Smith, Jaydeep K. Srimani, Tatyana A. Sysoeva, Sharon Bewick, David Karig, Lingchong You. Nature Microbiology, April 11, 2016. DOI: 10.1038/NMICROBIOL.2016.44
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