Nosocomial respiratory tract colonization and infection with aminoglycoside-resistant Acinetobacter calcoaceticus var anitratus: epidemiologic characteristics and clinical significance.
During the period July 1983 through December 1984, aminoglycoside-resistant Acinetobacter calcoaceticus var anitratus (ACA) were isolated from 98 patients in a university hospital. Eighty-seven percent of patients (85/98) acquired aminoglycoside-resistant ACA in the intensive care unit (ICU) and 92% (90/98) of all initial isolates were from sputum. ICU patients with respiratory colonization/infection with aminoglycoside-resistant ACA were compared with matched ICU controls with other gram-negative rods in sputum. Compared with controls, the duration of ICU stay prior to colonization/infection with aminoglycoside-resistant ACA was significantly longer for cases (14.7 days v 5.9 days, P = 0.002). Although exposures to devices and procedures were not significantly different for the two groups, cases received respiratory therapy significantly longer than did controls (14.7 days v 6.6 days, P = 0.006). Prior to isolation of aminoglycoside-resistant ACA in sputum, cases received more cephalosporins than did controls (1.9 v 1.2, P = 0.018); aminoglycoside usage in the two groups was comparable but cases tended to have received aminoglycoside for longer durations before colonization/infection than had controls (9.0 days v 6.1 days, P = 0.08). Following sputum isolation of ACA, 6 of 22 cases developed ACA bacteremia compared with bacteremia in 2 of 22 controls. We conclude that factors predisposing to colonization/infection with aminoglycoside-resistant ACA were extended ICU care, prolonged respiratory therapy, and prior therapy with cephalosporins and aminoglycoside. In addition, ACA may be a more common cause of secondary bacteremia than previously appreciated.
Peacock
J E
JE
Department of Medicine, Wake Forest University Medical Center, Winston-Salem, North Carolina 27103.
Sorrell
L
L
Sottile
F D
FD
Price
L E
LE
Rutala
W A
WA
D000150:Acinetobacter / Q000187:drug effects / Q000302:isolation & purification*; D000151:Acinetobacter Infections / Q000382:microbiology; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003428:Cross Infection / Q000382:microbiology / Q000635:transmission*; D004352:Drug Resistance, Microbial; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012137:Respiratory System / Q000382:microbiology*; D012141:Respiratory Tract Infections / Q000382:microbiology / Q000635:transmission*
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents