Acinetobacter baumannii: The Emergence of a Dangerous Multidrug-Resistant Pathogen

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By: Kerri-Lynn Conrad

Figure 1. A colored SEM depiction of Acinetobacter baumannii, an emerging multidrug-resistant pathogen that causes opportunistic infections associated with high mortality rates.

Introduction

Figure 2. SEM depiction of a cluster of gram-negative, non-motile, rod bacteria Acinetobacter baumannii.

Genome Structure

Figure 3. The genome of Acinetobacter baumannii consists of 3,976,746 base pairs. Several pathogenicity islands were identified in the genome through sequence homology comparisons.

Epidemiology

Figure 4. Several regions around the world are attempting to deal with outbreaks of Acinetobacter baumannii infection. Although Acinetobacter baumannii has been a problem in hospitals for many years, the pathogen started to receive attention after the rise in infections among soldiers serving in Iraq and Afghanistan.

Pathology

Figure 5. Acinetobacter baumannii can be found in the natural microbial flora of the human skin. However, some pathogenic strains can infect the human respiratory tract, open wounds, or the bloodstream. Acinetobacter baumannii's resistance to many antibiotics and diverse metabolism allows it to subsist in various environments.

Multidrug-Resistance

Figure 6. In a study conducted in four community hospitals on Acinetobacter baumannii infections in patients over the age of 60, the pathogen gained resistance to all 8 antibiotic classes tested in only five years.

Implications for Hospitals

Figure 7. Acinetobacter baumannii infections among immune compromised patients is a major problem in hospitals. Susceptible patients often obtain the infection from hospital equipment, staff members, or other patients.

Implications for Hospitals

Figure 8. An American soldier at a military field hospital battling Acinetobacter baumannii that infected an open wound.

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Edited by Kerri-Lynn Conrad, student of Joan Slonczewski for BIOL 238 Microbiology, 2011, Kenyon College.