TB bacteria screening marker gene: dif-hsp60-aacC1-tsr-dif resistance expression box.

Every year, 24 March is World Tuberculosis Day, and this year's theme is "Society Working Together to Eliminate the Harm of TB".
TB, known as rickets, continues to make a comeback with the drug "hide-and-seek" after the incidence has dropped to a low level, but inefficient and inaccurate drug screening evaluation models have been hampering the development of new drugs.
March 24, Zhang Tianyu of the Guangzhou Institute of Biomedicine and Health of the Chinese Academy of Sciences and the Tuberculosis Research Unit of the National Key Laboratory for Respiratory Diseases published his team's latest research results online in Frontiers in Microbiology: A Cassette Containing Thiostrepton, Gentami Resistance Genes and dif sequences is Effective in Construction of Recombinant Mycobacteria, the first author of the paper, Mugweru Julius, an international student at Guangzhou Institute of Biology, who has invented a new anti-expression box that efficiently builds mycobacteria free of resistance tags.
One of the reasons for the difficulty of genetic operation of
Mycobacteria tuberculosis is that the only screening marker genes available are the Kanr and Hygr, and they have some problems in practice.
TB bacteria are susceptible to spontaneous mutation resistance to carnamycin, so it is easy to screen for false positive colonies when screening recombinant TB strains.
In addition, carnamycin is one of the amino glycoside drugs used to treat tuberculosis, producing carnamycin-resistant TB bacteria that may cross-resistant to other anti-TB drugs such as streptomycin, resulting in dangerous drug-resistant TB bacteria.
many clinical strains are resistant to carnamycin.
, these strains cannot use Kanr as an resistance screening gene.
is very expensive, the use is large and the quality of different batches is not very stable.
first time, the team found that the sulfur streptococcus resistance gene (tsr) can be used as an anti-screening gene for TB bacteria, card-based seedlings, etc.
Sulphur streptococcus is relatively cheap, dosage is small, the mutation rate of TB bacteria that produce spontaneous sulfur-resistant streptococcus is very low, and it is not used to treat TB, do not worry about the production of TB bacteria resistant to it, and tsr can be used for the genetic operation of clinical bacteria, more ideal.
Gyeantamycin resistance gene (aacC1) can be used as an anti-screening gene for Mycobacteria (a commonly used fast-growing mode of mycobacteria) and E. coli.
this, the team added the two gene optimizations with suitable starters, along with an automatically dissocalable defoilable sequence on the 2nd side that can be identified by the Mycobacteria Xer system.
this constitutes a dif-hsp60-aacC1-tsr-dif resistance expression box.
it can be used to efficiently construct E. coli-Mycobacteria shuttle granules, which in turn can efficiently build recombinant mycobacteria without resistance screening markers, declared patents (2016101801161450).
the study was supported by the National Natural Science Foundation of China, the Chinese Academy of Sciences program, the UCAS scholarship, the CAS-TWAS scholarship, the Guangzhou Science and Technology Program and the National Key Laboratory Program for Respiratory Diseases.
.