Abstract
Pathogenic bacteria are capable of inflicting damage to the infected host, thereby causing disease. Importantly, the different body habitats have distinct physical-chemical properties as to pH and abundance of molecular oxygen and water, which allow the presence and growth of specific types of bacteria. Treponema pallidum subspecies pallidum, the bacterium which causes syphilis and Streptococcus pyogenes (Group A streptococci), which is associated with suppurative skin and mucosal infections, necrotizing fascitis, scarlet fever, and sequelae such as glomerulonephritis and rheumatic fever, are examples of extracellular obligate human pathogens. Most virulence factors only act locally at the site of infection, whilst others, are also transported to distal parts of the body, where they subvert host cell functions. Importantly, bacteria growing in biofilms are able to partially evade the immune response and are resistant to antibiotic treatment. The causes and mechanisms of genetic variation account for the evolution of both commensal and pathogenic bacteria. The difference lies in the fact that in pathogens virulence factors are acquired. However, sometimes it is not easy to distinguish a true virulence factor from a feature that just increases the bacterial fitness without really harming the host.
Original language | English |
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Title of host publication | The immune response to infection |
Editors | Stefan H. E. Kaufmann, Barry T. Rouse, David L. Sacks |
Publisher | John Wiley & Sons Ltd |
Chapter | 12 |
ISBN (Electronic) | 9781683671190 |
ISBN (Print) | 9781555815141 |
DOIs | |
Publication status | Published - 30 Nov 2010 |
Externally published | Yes |