Chapter 26 - Molecular Methods for Identification and Characterization of Acinetobacter spp.

Abstract

This chapter focuses on current challenges in the clinical laboratory setting for identification, susceptibility testing, and epidemiology of Acinetobacterspp. The application of various molecular methods to aid in the generation of accurate information in the healthcare environment is discussed. Acinetobacteris a uniquely successful organism that is now presenting unusual challenges in terms of its detection and treatment in human disease. Classification of species within this genus has historically presented difficulty owing to the genetic diversity of this organism. Application of various molecular typing methods has been instrumental in the definition of the 31 described species of Acinetobacter, as phenotypic methods may not achieve adequate levels of speciation. Based on DNA sequence homology, the A. baumannii–A. calcoaceticuscomplex consists of four members: A. baumannii, genospecies 3 and 13TU, and A. calcoaceticus. Of these, A. baumanniiis most clinically significant in human disease. Acinetobacterspp. has been isolated from extremely diverse environments and is well adapted to multiple sites on the human host. Pneumonia, bacteremia, and wound infections are the most common manifestations of Acinetobacterin the ICU. A. lwoffiiis also a significant cause of nosocomial infections. A significant development is the emergence of Acinetobacterstrains with resistance to multiple classes of antibiotics.