Hello and Welcome,
triple or even quadruple antibiotic combinations are common in the treatment of chronic Lyme disease and co-infections
however Daptomycin is a IV only antibiotic - its also not widely used and until recently the price was very high compared to other antibiotics - around $500USD per dose - so its very rarely used in Lyme patients - despite the promising mouse studies.
more info on daptomycin here
https://www.drugs.com/dosage/daptomycin.htmlalso we have to bear in mind that humans are not mice - and so while these results do show efficacy in-vivo - which is certainly encouraging - mice do not get lyme disease as found in humans - and so are not a perfect model for chronic Lyme in humans. in particular the interaction between the host immune system and the bacterium is critical in determining illness or recovery - and mice and humans clearly differ in this regard - so we have to be a little careful of directly applying mouse data to humans.
Paper said...
No strain of inbred mice develops erythema migrans, meningitis or encephalitis, and thus all are imperfect models for human Lyme disease.
source:
https://pmc.ncbi.nlm.nih.gov/articles/pmc3313462/because IV antibiotics have greater risks associated with their use than oral antibiotics - generally only a small proportion of Lyme patients are treated with IV antibiotics - usually only those that are in the most severe condition - or have some life threatening complication - such as endocarditis or severe neuroborreliosis.
most LLMDs treat the majority of patients with oral antibiotic combinations
regarding persister cells - actually all populations of borrelia contain persister cells - and contains normal cells that are able to be triggered to form persister cells - just in different proportions depending on stressors in their environment - these stressors include the innate immune defences of the host as well as things like nutrient availability. even in the absence of overt stressors - there are always some persister cells. The proportion varies depending on the hyperlocal conditions - ie the cellular level.
if you grow a culture of borrelia in in ideal conditions in the lab - you will initially get a large proportion of normally metabolising logarithmically growing cells - but as soon as you introduce a stressor - for instance an antibiotic like doxycycline - a significant proportion will turn into persister cells within 24hrs - so its an inherent property of the bacteria - rather than something that only forms over months or in chronic patients
however, there is a correlation as, in chronic infection, more biofilms are thought to build up in tissues over time (autopsies of human chronic lyme patients have found extensive biofilm colonies in tissues) and as a biological consequence cells deep inside biofilms have less access to nutrients and as a result persister cell proportions are associated with biofilm formation.
actually this property of persister cells is not unique to borrelia - its actually very common in the bacterial world - like biofilms - something like 90% of known bacteria are capable of forming them.
i hope its of some help.