Ao. Osoba, ANTIMICROBIAL SUSCEPTIBILITY PATTERN OF GRAM-NEGATIVE AEROBIC ISOLATES FROM INTENSIVE-CARE UNITS IN SAUDI-ARABIA - A MULTICENTER STUDY, Saudi medical journal, 18(5), 1997, pp. 471-475
Objective: To determine the pattern and prevalence of recognized categ
ories of resistance to broad-spectrum antibiotics in seven Intensive C
are Units (ICUs) in the Kingdom. Design: A multicenter study was estab
lished to carry out susceptibility tests on at least 100 isolates from
patients admitted into ICUs of seven hospitals in various areas in th
e Kingdom. Tests were performed using the Microscan MIC Plus type MIC
panel. Setting: Microbiology laboratories and ICUs of seven hospitals
in the Kingdom. Subjects: Four hundred and seventy eight patients admi
tted into the study provided 703 isolates, which were examined for bet
a-lactamase production. Main outcome measures: The dominant species is
olated were Ps. aeruginosa (148), E. coli (117) and Kleb. pneumoniae (
11). Results: In all but one center, most isolates resistant to 3rd ge
neration cephalosporins were E. coli and Klebsiella spp. with multi-re
sistance pattern consistent with extended spectrum B-lactamase (ESBL).
Inducible Enterobacteriaceae (IE), with chromosomal type-1 cephalospo
rinases were next in importance, followed by Ps. aeruginosa. Amikacin
was the most effective aminoglycoside least affected by IE, while amox
il/clavulanate had a low impact on conferring sensitivity on the isola
tes. Conclusions: Blood culture isolates showed a strong contribution
of resistance from inducible Enterobacteriaceae, principally nosocomia
l Serratia spp. and Enterobacter spp. with linked resistance to the am
inoglycosides. The superiority of imipenem and ciprofloxacin over othe
r antibiotics for empiric therapy of bacteremia in ICU patients was ev
ident from the susceptibility data of all isolates.