Keywords : Uropathogenic E


The Location of Aerobactin Determinants of Uropathogenic E. coli in Association with Hemolysin Production Antibiotic Resistance and Patient Characteristics.

Ibtesam Ghadban Auda

Iraqi Postgraduate Medical Journal, 2006, Volume 5, Issue 2, Pages 223-229

ABSTRACT:
BACKGROUND:
Aerobactin, Hemolysin and the resistance to some antibiotics axe important Features of
Uropathogenic E. coli (UPEC). The characteristics of patients from which we isolate the
UPEC have associate with these Features and their determinants location.
AIM:
We determined the phenotypic expression and gene location of Aerobactin and phenotypic
expression of Hemolysin among 60 UPEC isolates. We correlated the presence of Aerobactin system
with antibacterial agents resistance. The expression of Hemolysin and the characteristics of patients.
METHODS:
Two methods of plasmid curin, sodium dodecyl sulfate and elevated temperature plasmid curing, are
used then plasmid extraction and agarose gel electrophoresis are performed to determine the
location of Aerobactin determinants and the size of Aerobactin plasmids, as well as the location of
the determinants of some antibiotics resistance which were ampicillin (Am), Tetracycline (Tc),
gentamicin (GM), Chloramphenicol (C) and co- trimazole (Co).
RESULTS:
Aerobactin and hemolysin expression among UPEC isolates were 93.3% and 35% respectively. The
isolates of non compromised patients produce statistically higher rate of expressed hemolysin (90.5%
, p<0.01). Plasmid- borne Aerobactin was absent in UPEC isolates of non compromised patients
(89.5%, p<0.01). On the contrary compromised patient isolates express plasmid Aerobactin of 59.5%
(p<0.02). We also found that Aerobactin determinants are located on a plasmid in compromised
patient isolates and associated with the absence of chromosomal Hemolysin production (82.9%,
p<0.01). Yet, The chromosomal aerobactin is associated with hemolysin production (61.9%,
p<0.02). Furthermore, UPEC isolates of compromised patients carry relatively large plasmid of
Aerobactin (85.7%. p<0.05) and these large plasmids carry either chloramphenicol (83.3%.p<0.02) or
gentamicin determinants (100%. P<0.01) but not co- trimazole, tetracycline or ampicillin.
CONCLUSION:
The isolates of non compromised patients carry chromosomal Aerobactin and hemolysin. While the
isolates of compromised patients express plasmid Aerobactin and do not express chromosomal
hemolysin. Aeobactin plasmids are relatively large plasmids and carry either chloramphenicol or
gentamicin resistance determinants.