Bacterial persistence and expression of disease

Area of Science:

• Microbiology
• Infectious Diseases
• Pathogenesis

Background:

• Experimental and clinical evidence suggests difficult-to-culture and dormant bacteria contribute to infection latency and pathogenicity.
• Persistent bacteria can adopt diverse forms and functions within a host environment, differing significantly from free-living states.

Purpose of the Study:

• To review the diverse forms and functions of individual bacteria, linking them to patient care.
• To correlate basic biology of persistent bacteria with disease expression, focusing on latency and chronicity mechanisms.
• To present cases of idiopathic conditions potentially caused by cryptic bacteria.

Main Methods:

• Review of experimental studies on host-bacterium interactions.
• Analysis of data correlating persistent bacteria biology with disease.
• Case series illustrating idiopathic conditions linked to cryptic bacteria.
• Utilizing Polymerase Chain Reaction (PCR) to identify nonculturable bacilli.

Main Results:

• Most bacteria exposed to adverse host environments can assume aberrant forms.
• Wall-defective bacterial forms can survive and persist in a latent state, causing disease.
• PCR identified previously nonculturable bacilli in Whipple's disease and bacillary angiomatosis.

Conclusions:

• Persistent, dormant bacteria are implicated in infection latency and chronic diseases.
• The concept of wall-defective forms explains bacterial survival and pathogenicity in certain infections.
• Molecular data may necessitate redefining Koch's postulates for nonculturable, dormant bacterial pathogens.