Researchers Created Safe Antibiotic-Free Parasite Strain
A new transgenic Leishmania tarentolae strain was engineered without antibiotic resistance genes.
Updated on Oct. 1, 2026 in Life Sciences
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Researchers have successfully engineered a strain of the parasite Leishmania tarentolae that lacks antibiotic resistance genes. This development addresses safety concerns surrounding the use of antibiotic markers in live vaccine candidates.
Why it matters
The use of antibiotic resistance genes as selection markers poses significant safety risks for potential human applications. Removing these genes helps create safer platforms for developing live vaccines using transgenic organisms.
The team utilized CRISPR-Cas9 technology to integrate sand fly salivary proteins, PpSP15 and PsSP9, into the SSU locus of the parasite. Successful gene expression was verified through DNA, RNA, and protein analysis.
The details
By removing the neomycin resistance gene from the pLEXSY-Neo vector, the team created the pLEXSY-noNeo system to eliminate reliance on antibiotic selection. Mutant parasites maintained infectivity levels comparable to those of wild-type strains, proving the platform remains viable for research.
Timeline
The findings were published on October 1, 2026.
Deeper Dive
This development marks a significant modification to the pLEXSY expression system by removing antibiotic resistance markers to improve safety. It shifts the standard for producing transgenic parasites by removing reliance on markers that have historically complicated clinical applications.
This breakthrough could lead to the development of safer live vaccine platforms for infectious diseases. By eliminating antibiotic resistance genes, researchers can accelerate the path toward therapeutic applications that are safer for patients.
The takeaway
The successful creation of this strain demonstrates that essential research can proceed without relying on potentially hazardous antibiotic resistance markers. This approach sets a new benchmark for safety in the production of transgenic vaccine candidates.
Further reading
For more advancements in biotechnology, visit our Life Sciences section.
More information
Read the full results in the scientific research article.
Source note: This article includes information reported by Nature.
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