Acinetobacter sp can cause suppurative infections in any organ system and are often opportunists in hospitalized patients.

Acinetobacter is ubiquitous and can survive on dry surfaces for days. Risk factors for hospital-acquired infection include length of stay, surgery, wounds, previous infection, fecal colonization with Acinetobacter, treatment with broad-spectrum antibiotics, parenteral nutrition, indwelling devices, ICU stay, and mechanical ventilation. Risk factors for community-acquired infection include alcoholism, cigarette smoking, chronic lung disease, diabetes mellitus, and residence in a tropical developing community.

Acinetobacter sp can cause suppurative infections in any organ system. It is often an opportunist in hospitalized patients. The significance of isolates from clinical specimens is difficult to determine because they often represent colonization.

The respiratory system is the most common site for infection. Acinetobacter easily colonizes tracheostomy sites. Acinetobacter causes community-acquired bronchiolitis and tracheobronchitis in healthy children and tracheobronchitis in immunocompromised adults. Spread in ICUs has been attributed to colonized health care practitioners, contaminated common equipment, and contaminated parenteral nutrition solutions. Hospital-acquired Acinetobacter pneumonias are frequently multilobar and complicated. Secondary bacteremia and septic shock are associated with a poor prognosis.

Rarely, Acinetobacter causes meningitis (primarily after neurosurgical procedures), cellulitis or phlebitis with an indwelling venous catheter, ocular infections, native and prosthetic valve endocarditis, osteomyelitis, septic arthritis, and pancreatic and liver abscesses.

In patients with localized cellulitis or phlebitis associated with a foreign body (eg, IV catheter or suture), removal of the foreign body with local care is generally sufficient. Tracheobronchitis after endotracheal intubation may resolve with pulmonary toilet alone. Patients with more extensive infections should be treated with antibiotics and debridement if necessary.

Acinetobacter tends to be resistant to many antimicrobials. Typically, imipenem can be used. However, outbreaks of imipenem-resistant Acinetobacter have occurred. Sulbactam has intrinsic bactericidal activity against many multidrug-resistant Acinetobacter s trains. Although mild to moderate infections may respond to monotherapy, serious infections are treated with combination therapy. Bactericidal synergy occurs when several antimicrobials (eg, carbenicillin, imipenem, β-lactam/β-lactamase inhibitor) are combined with an aminoglycoside.

A hospital outbreak involving multidrug-resistant Acinetobacter strains with similar antibiograms should prompt an infection control investigation of compliance with hand washing, barrier precautions, ventilator care, and housekeeping.

Last full review/revision November 2005