Therapeutic options for infections caused by Klebsiellapneumoniae strains expressing plasmid-mediated AmpC -lactamases are limited because these organisms are usually resistant to all the -lactam antibiotics, except for cefepime, cefpirome, and the carbapenems. These organisms are a major concern in nosocomial infections.Information on such pathogens is not available from Iraq. Therefore there is an increasing demand to investigate the role of these strains in hospital infections. This book provides the occurrence and diversity of plasmid-mediated AmpC -lactamases in K. pneumoniae isolates recovered from both hospital and community settings in Iraq.