Acinetobacter spp, as nosocomial pathogens: Microbiological, clinical, and epidemiological features

Acinetobacter spp., especially A. baumannii, now account for a substantial proportion of endemic nosocomial infections. These organisms are associated particularly with ventilator-associated pneumonia inpatients confined to hospital intensive care units, bur numerous other infections including bacteremia, urinary a act infection, and meningitis have also been reported. Acinetobacter spp. have a significant capacity for long-term survival in the hospital environment, with corresponding enhanced opportunities for transmission between patients either via human reservoirs or via inanimate materials. The revised taxonomy of this genus, combined with the development of new molecular identification and typing methods, should now allow detailed epidemiological studies of genotypically related strains involved in outbreaks of hospital infection. Acinetobacter infections are often difficult to treat because of the wide-spread antibiotic resistance found in this genus. Various mechanisms of resistance have been recognized, and combination therapy is usually necessary for effective treatment. Continued awareness of the need to maintain good housekeeping and control of the environment, including equipment decontamination, strict attention to hand washing and isolation procedures, and control of antibiotic usage, especially in high-risk areas appears to be the combination of measures most likely to control the previously unabated spread of Acinetobacter spp. in hospitals.