Persistent bacterial infections: The interface of the pathogen and the host immune system

Department of Microbiology and Immunology, Stanford School of Medicine, Stanford University, Stanford, California 94305, USA.
Nature Reviews Microbiology (Impact Factor: 23.57). 10/2004; 2(9):747-65. DOI: 10.1038/nrmicro955
Source: PubMed


Persistent bacterial infections involving Mycobacterium tuberculosis, Salmonella enterica serovar Typhi (S. typhi) and Helicobacter pylori pose significant public-health problems. Multidrug-resistant strains of M. tuberculosis and S. typhi are on the increase, and M. tuberculosis and S. typhi infections are often associated with HIV infection. This review discusses the strategies used by these bacteria during persistent infections that allow them to colonize specific sites in the host and evade immune surveillance. The nature of the host immune response to this type of infection and the balance between clearance of the pathogen and avoidance of damage to host tissues are also discussed.

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    • "To represent the agent-vector-host transmission process, we made a series of simplifying assumptions based on transmission dynamics that have been well-described for various tick-borne disease systems, which we feel represent a plausible transmission environment for our hypothetical pathogen transmitted by a prototypical three-host tick. We assumed: (1) all hosts and all post-embryonic tick life stages can become infected (Stromdahl et al., 2000; Yabsley, 2010), (2) transstadial transmission in ticks occurs (Dennis and Piesman, 2005), (3) no transovarial transmission in ticks occurs (Groves et al., 1975; Long et al., 2003); (4) lifelong infection of hosts (Monack et al., 2004), and (5) no transplacental transmission by hosts (Mather et al., 1991). To help isolate the effects of changes in host density on the prevalence of infected ticks, we also assumed that tick-to-host and host-to-tick transmission probabilities were the same. "
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    • "The remodelled vacuole blocks the fusion of the lysosomes and this permits the intracellular survival and replication of the bacteria within the host cells. The capability of the bacteria to survive within macrophages allows them to be carried in the reticuloendothelial system (RES) (Monack et al. 2004). "
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