Cell Wall-Deficient Bacterial Infections

Chapter 39

Cell Wall–Deficient Bacterial Infections

Etiologic Agent and Epidemiology

Cell wall–deficient bacteria (CWDB), also known as L-phase or L-form bacteria, are bacterial variants that lack a cell wall, although they may in fact possess small amounts of peptidoglycan.2 The name L-form was given to these bacteria because they were discovered at the Lister Institute in London. L-form bacteria are distinct from mycoplasmas, because Mycoplasma spp. do not originate from bacteria that normally possess a cell wall. A huge variety of gram-positive and gram-negative bacterial species may become CWDB when exposed to certain stressors in the laboratory (such as antimicrobial drugs) (Box 39-1). Some of these bacteria remain as CWDB (stable L-forms), whereas others revert back to possession of a cell wall (unstable L-forms). CWDB assume a spherical or pleomorphic shape, and are susceptible to osmotic lysis. However, they resist β-lactam drugs such as penicillin, and may be able to evade the innate immune response. Thus, it has been proposed that reversion to cell wall–deficient forms may be a mechanism of bacterial persistence. Although the formation of CWDB has been well documented in the laboratory, the role that CWDB play in disease remains controversial.3

Jul 10, 2016 | Posted by in INTERNAL MEDICINE | Comments Off on Cell Wall-Deficient Bacterial Infections

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