Abstract:
This study was carried out in Khartoum state during the period from November
2008 to March 2009, to determine the occurrence and antimicrobial resistance of
Enterobacter
aerogenes isolated from patients
suffering from urinary tract
infections and wound infections.
Three hundred and thirty nine urine specimens and seventeen wound exudates
specimens were collected from patients attending Military Hospital, Omdurman
Teaching Hospital and Khartoum Teaching Hospital. Both specimens were cultured
on blood and MacConkey's agars. Identification of the isolates was done by
colonial morphology, Gram stain and biochemical tests using API E 20.
Modified Karby-Bayer diffusion method was adopted to determine the resistance
rate of E. aerogenes isolated from urine, to nitrofurantoin, co-trimoxazole, nalidixic
acid, amoxyclave and amoxicillin also to determine the resistance rate of E.
aerogenes isolated from infected wound, to amikacin, ciprofloxacin, ceftriaxone,
ticarcillin and amoxicillin. Minimum inhibitory concentration (MIC) was done to co-
trimoxazole, amoxicillin, amikacin,
ciprofloxacin and ticarcillin
antibiotics by E
-test.
Of the three hundred and thirty nine urine specimens and seventeen wound
exudates specimens examined, 11 (3.1%) E. aerogenes were recovered. 7 (0.6%) of
the isolates were recovered from urine specimens and rest 4 (0.3%) were recovered
from wound exudates specimens.
The results revealed that the antimicrobial resistance of E. aerogenes
follows; Co-trimoxazole,
ceftriaxone,
ticarcillin
was as
and amoxycillin (100% each),
nalidixic acid and amoxyclave (85.7% each), nitrofurantoin (42.8%), amikacin and
ciprofloxacin(0%).
The result indicated that the MIC, MIC 50, MIC90 of ciprofloxacin were (0.05 to
0.06 μg/ml, 0.05μg/ml and 0.06μg/ml), co-trimoxazole, amoxycillin, and ticarcillin
(>240μg each) and amikacin (0.5-1μg/ml, 0.5μg/ml and >30μg/ml).
The study concluded that the existence of E. aerogenes in clinical specimens was
slightly high compare to other bacteria. The antimicrobial resistance of E.
aerogenes to most traditionally used antibiotics was very high.
