Environ Microbiol. 2017 Oct;19(10):3846-3862. doi: 10.1111/1462-2920.13897. Epub 2017 Sep 11.
Sleeper cells: the stringent response and persistence in the Borreliella (Borrelia) burgdorferi enzootic cycle.
Cabello FC1, Godfrey HP2, Bugrysheva JV1, Newman SA3.
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Abstract
Infections with tick-transmitted Borreliella (Borrelia) burgdorferi, the cause of Lyme disease, represent an increasingly large public health problem in North America and Europe. The ability of these spirochetes to maintain themselves for extended periods of time in their tick vectors and vertebrate reservoirs is crucial for continuance of the enzootic cycle as well as for the increasing exposure of humans to them. The stringent response mediated by the alarmone (p)ppGpp has been determined to be a master regulator in B. burgdorferi. It modulates the expression of identified and unidentified open reading frames needed to deal with and overcome the many nutritional stresses and other challenges faced by the spirochete in ticks and animal reservoirs. The metabolic and morphologic changes resulting from activation of the stringent response in B. burgdorferi may also be involved in the recently described non-genetic phenotypic phenomenon of tolerance to otherwise lethal doses of antimicrobials and to other antimicrobial activities. It may thus constitute a linchpin in multiple aspects of infections with Lyme disease borrelia, providing a link between the micro-ecological challenges of its enzootic life-cycle and long-term residence in the tissues of its animal reservoirs, with the evolutionary side effect of potential persistence in incidental human hosts.

PMID: 28836724 DOI: 10.1111/1462-2920.13897
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Comment by Sunny--Gwen Simmons:

With these continuing peer-reviewed publications demonstrating persistence of Borrelia, I do not understand the ongoing denial and lack of acceptance by the medical community at large of the true and far-reaching mortality and morbidity risks this bacteria poses. GWEN "Sunny" Simmons