Community-Acquired Acinetobacter radioresistens Bacteremia in an Immunocompetent Host

Abstract

Acinetobacter species are gram-negative coccobacilli ubiquitous in nature and widely distributed in the environment. Acinetobacter baumannii is a bacteria commonly seen in the hospital setting, responsible for causing a wide range of bloodstream infections, urinary tract infections, secondary meningitis, infective endocarditis, and wound infections, and is the cause of outbreaks mainly due to its antimicrobial resistance patterns. The use of broad-spectrum antibiotic coverage with carbapenems is essential in the hospital setting. Therefore, carbapenem-resistant Acinetobacter baumannii (CRAB) poses as a very challenging pathogen. Acinetobacter radioresistens, a rare species in comparison to the more prevalent Acinetobacter baumannii, is an underestimated agent in causing nosocomial infections and also is a potential disseminator of resistance genes. It is also resistant to gamma radiation at 4-8 times higher than other Acinetobacter spp. and is the source of the class D OXA-23 carbapenemase that can confer carbapenem resistance. Therefore, immediate and precise identification of A. radioresistens is crucial for the clinical management of multidrug-resistant bacteremia.

Keywords: acinetobacter; acinetobacter baumannii; acinetobacter radioresistens; bacteremia; bacteremia in immune-competent individuals; carbapenem resistance; carbapenemase; maldi-tof; multidrug-resistant acinetobacter; pneumonia.

Figure 1. Chest radiograph on admission

The opacity at the left retrocardiac region (white arrows) is suspicious for left lower lobe pneumonia versus atelectasis

Figure 2. Chest radiograph

When compared with the previous study, there is mildly improved aeration at the left lung base (yellow arrows)