[Construction of in-frame deletion streptococcal hemoprotein receptor gene mutant in Streptococcus equi subsp. zooepidemicus].
OBJECTIVE
To construct the in-frame deletion gene mutants in streptococcus equi subsp. zooepidemicusby (S. zooepidemicus) by pJR700 plasmid, a thermosensitive delivery vector system.


METHODS
With PCR we amplified a 4017-bp DNA fragment of streptococcal hemoprotein receptor gene from chromatosome DNA. This DNA fragment was subcloned into the pJR700 plasmid to create pXL28. Using pXL28 as the template we got the DNA fragment deleted 1831 bp in streptococcal hemoprotein receptor gene by inverse PCR amplification and ligated the in-frame deletion DNA fragment by T4DNase to create pXL30. Then pXL30 was transformed into S. Zooepidemicus by electroperation. The kanamycin( kan)-resistant clones were selected at 37 degrees C in the presence of kan for three rounds. To induce excision of the plasmid vector sequence, the culture was shifted to 30 degrees C and grown without antibiotics for four rounds. Colonies with kan sensitivity, which indicated that the plasmid had been excised, were selected by plating on THY agar at 37 degrees C. S. Zooepidemicus mutants were identified through PCR with primers homologous to the flanking regions and the streptonigrin sensitive test.


RESULTS
The in-frame deletion streptococcal hemoprotein receptor mutants were successfully built in S. Zooepidemicus.


CONCLUSIONS
The thermosensitive delivery vector system of pJR700 could be utilized to construct the in-frame deletion gene mutant strains of S. Zooepidemicus.
Li
Yao
Y
School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.
Lan
Xiaoling
X
Li
Xueru
X
Guo
Tailin
T
Yao
Ning
N
Jiang
Nanping
N
Ren
Yaoyao
Y
D001426:Bacterial Proteins / Q000235:genetics*; D006420:Hemeproteins / Q000235:genetics*; D010957:Plasmids / Q000235:genetics; D017384:Sequence Deletion; D018502:Streptococcus equi / Q000235:genetics*
D001426:Bacterial Proteins; D006420:Hemeproteins