Bacterial Pathogens.

Bacterial infections represent important diseases worldwide despite decades of antibiotic therapy. Diverse microbial pathogens continue t rapidly evolve and present challenges for medical practice that will require ongoing refinements in laboratory-based diagnostic strategies. Since the 1970s, the steady parade of bacterial pathogen discoveries such as Legionella pneumophila, Helicobacter pylori, and Bartonella henselae have highlighted the ongoing importance of bacterial evolution in human infectious diseases. Established bacterial pathogens such as Streptococcus pyogenes and Mycobacterium tuberculosis have reemerged during the past two decades. Drugresistant pathogens including multidrug-resistant organisms spread to different geographic areas, ignoring regional boundaries with the assistance of global immigration and travel. Advances in medicine including oncology and transplantation have resulted in greater numbers of immunocompromised patients with increased risks for invasive bacterial infections. [ABSTRACT FROM AUTHOR]