[Construction and characterization of mutant Enteroaggregative E. coli O42 strain with high-pathogenicity island deletion].
OBJECTIVE
To construct and characterize a mutant Enteroaggregative E. coli(EAggEC) O42 strain with in-frame deletion of high-pathogenicity island (HPI).


METHODS
The kanamycin resistance gene (kan) was inserted between the sequences of irp8 and irp5 genes as the two homologous sequences for construction of the recombinant plasmid pCO85 by subcloning the recombined sequence into the suicide vector pCVD442. By homologous recombination and conjunction mobilization, EAO85 mutant with deletion of the core region of HPI about 24 kb spanning from irp8 to irp5 sequences was screened.


RESULTS
Irp8 and irp5 genes of EAggEC O42 were exchanged by pCO85 by conjunction mobilization with the selection by sucrose. The EAO85 mutant was identified by their failure to yield PCR products with primers specific for the internal regions of HPI.


CONCLUSIONS
We have successfully constructed a mutant of EAggEC O42 strain with HPI in-frame deletion, which may facilitate the exploration of the role of HPI in EAggEC strain.
Hu
Jing
J
Department of Epidemiology, Southern Medical University, Guangzhou 510515, China. jing-hu@163.net
Yu
Shou-yi
SY
Kan
Biao
B
Liu
Zhi-hua
ZH
D001422:Bacterial Adhesion / Q000235:genetics; D001427:Bacterial Toxins / Q000235:genetics; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000096:biosynthesis* / Q000235:genetics; D036781:Fimbriae Proteins / Q000096:biosynthesis* / Q000235:genetics; D017353:Gene Deletion; D014774:Virulence
C079725:AggA protein, E coli; D001427:Bacterial Toxins; D029968:Escherichia coli Proteins; D036781:Fimbriae Proteins