Table 2.

Presence of aerobactin and linkage of SHI-3int to pheU in Shigella andE. coli strains

Species and strainSerotypeAerobactin synthesisint3a (linked to pheU)bint2c(linked to selC)d
S. boydii
 1-16601+
 1-10972+
 0-13925++ (+)
 0-13935++ (+)
 2248607++ (+)
 0-53539+
 0-159111++ (−)
S. flexneri e
 SA1002a++ (−)+ (+)
 5 strains1a++ (+)
 9 strains1b++ (+)
 20 strains2a++ (−)+ (+)
 9 strains2b++ (−)+ (+)
 10 strains3a++ (+)
 11 strains3b++ (+)
 8 strains3c++ (+)
 4 strains4a++ (+)
 9 strains4b++ (+)
 9 strains5++ (−)+ (+)
 6 strains6+
S. dysenteriae
 0-45761+ (+)
 1-1302++ (+)
 0-42423+
 9-34854+
 2177269+
S. sonnei
 1-679++ (−)+ (+)
 EN120++ (−)+ (+)
EIEC
 930-78O124:H
 550-3076++ (−)
 1107-81++ (−)
  • a PCR with primer pair 2-3 amplifies a 395-bp product internal to SHI-3 int3.

  • b Linkage determined by PCR with primer pair 1-3, where primer 1 is in yjdC and primer 3 is in SHI-3int3.

  • c PCR with primer pair 6-8 amplifies a 120-bp product internal to SHI-2 int2.

  • d Linkage determined by PCR with primer pair 7-8, where primer 7 is in selC and primer 3 is in SHI-2int2.

  • e Each serotype pool contains the indicated number of clinical isolates from the Texas Department of Health.