Acinetobacter baumanii Causes Lower Respiratory Tract Infection in a Patient

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Presentation

A 2-year-old female presents to the Emergency Department with seizures and an onset of fever. The patient was diagnosed with Enterobacter cloacae bacteremia and treated with meropenem. A chest x-ray was ordered along with a bronchoalveolar lavage (BAL) bacterial culture. The chest x-ray was abnormal and showed a collapsed lung. While in the hospital, the patient had a second aspiration event and was placed on a mechanical ventilator but within 2 days her condition worsened so she was transferred to a Children’s hospital that required treatment with an artificial lung. 

Lab Testing

Gram stain of the BAL revealed 2+ Gram-negative coccobacilli and polymorphonuclear leukocytes. Growth on sheep blood agar showed non-pigmented, translucent and smooth colonies. On MacConkey agar, colonies had a pinkish tint and were non-lactose fermenting. The laboratory identified the Gram-negative coccobacilli as Acinetobacter baumanii. Susceptibility results showed that the organism was multi-drug resistant to many antibiotics. 

Cause of Symptoms

Acinetobacter baumanii is an opportunistic pathogen that can cause a range of different diseases, such as lower respiratory tract infections and pneumonia in critically ill patients. Acinetobacter baumanii is a Gram-negative pleomorphic bacillus which is a non-fermenting, aerobic bacterium found in the natural environment. A. baumanii is recognized worldwide as a nosocomial pathogen causing hospital associated infections. From an infection control perspective, it can be difficult to control the spread of this organism in the hospital environment. The organism can easily develop antibiotic resistance and has the ability to survive on inanimate objects. It is a common pathogen in ventilator associated pneumonia.  A. baumanii can also cause blood stream, wound and urinary tract infections. 

Treatment

Patient was treated with polymyxin B and meropenem in combination. Dose adjustment and monitoring of polymyxin B is important in patients due to the nephrotoxicity of the drug. 

Contact Information

Nicole Jackson, njackson@asmusa.org