Tag Archives: ying zhang

borrelia burgdorferi_mice

GLA POV: Ability of Stationary Phase Persister/Biofilm Microcolonies of Borrelia burgdorferi to Cause More Severe Disease

by Timothy Sellati, Ph.D., Chief Scientific Officer, GLA

Ying Zhang, Ph.D., a Global Lyme Alliance (GLA)-funded investigator, and his team at Johns Hopkins University just published a seminal study in the journal Discovery Medicine titled “Stationary phase persister/biofilm microcolony of Borrelia burgdorferi causes more severe disease in a mouse model of Lyme arthritis: Implications for understanding persistence, post-treatment Lyme disease syndrome (PTLDS), and treatment failure”.

Lyme disease patients, infected via tick bite with the bacterial spirochete B. burgdorferi, are routinely treated with two to four weeks of Doxycycline, Amoxicillin, or Cefuroxime, which is curative in many cases if treated at the onset of the infection. However, research shows that despite treatment, up to 20% of patients continue to suffer lingering symptoms of fatigue, pain, or joint and muscle aches, and neurocognitive manifestations that last 6 months or more.  This clinically-defined condition is known as post-treatment Lyme disease syndrome (PTLDS).  A long-standing mystery is whether development of PTLDS reflects 1) persistence of B. burgdorferi in a patient’s tissues, consistent with chronic infection, or 2) self-perpetuating inflammation caused by tissue damage triggered by the original infectious insult.

Zhang and colleagues published several influential papers over the past five years revealing a potential answer to this mystery. His lab showed that in vitro stationary phase (non-growing) cultures of B. burgdorferi contain different morphological variants. These bacterial variants include planktonic (free-swimming) spirochetal forms, round body forms, and aggregated microcolony (biofilm-like) forms, which have varying levels of persistence (e.g., the capacity to tolerate antibiotic exposure) in comparison to the log phase culture, which mainly consists of rapidly growing spirochetal forms with no or few persisters. B. burgdorferi develops into these morphological variants under stress conditions but their relevance to severe and persistent Lyme disease was unclear until the publication of this new study.

Zhang et al. report that biofilm-like microcolony (MC) and planktonic (free-swimming spirochete and round body; SP) variants found in stationary phase cultures were not only more tolerant of exposure to antibiotics but also caused more severe arthritis in mice than the log phase spirochetes (LOG). Importantly, the authors show that the murine infection caused by LOG could be eradicated by Ceftriaxone (CefT) whereas the persistent infection established with MC could not be eradicated by Doxycycline (Doxy), CefT, or Vancomycin (Van), or Doxy+CefT or Van+CefT, but could only be eradicated by the persister drug combination Daptomycin (Dapto)+Doxy+CefT. This GLA-funded work establishes for the first time that varying levels of persistence and the severity of disease pathology caused by infection with B. burgdorferi is linked to different morphological forms of the spirochete.

The following facts highlight the importance of this novel discovery. The number of patients developing PTLDS, or chronic Lyme, which is less clinically well-defined, is on the rise; a trend that is consistent with the rise in annual incidence of Lyme disease, which is ~427,000 cases. The absence of a full understanding of the cause(s) of PTLDS hampers efforts to effectively treat patients suffering with this syndrome. The authors demonstrated that the degree of persistence or persistent infection varied with different inoculae, where biofilm-like microcolony inoculae produced a more severe and persistent disease that could not be eradicated by the current Lyme antibiotics or even some two-drug combinations but could be eradicated by the persister drug combination Dapto+Doxy+CefT. In contrast, the disease induced by the log phase spirochetal forms is more readily eradicated by CefT. That the inclusion of persister drug Dapto, in combination with Doxy and CefT, is critical for eradicating the persistent infection established by persister inoculae validates the relevance of Dr. Zhang’s GLA-funded efforts to screen for drugs or drug combinations against stationary phase bacteria enriched in persisters in vitro, which were published by Feng et al. in 2014 and 2015 (see influential papers here).

Finally, the reported findings may not only provide a new understanding of PTLDS and perhaps chronic Lyme disease, but also will inform and accelerate development and testing of novel persister drug combination regimens that can more effectively cure persistent Lyme disease in the future. GLA’s goal in the near future will be to support human clinical trials to evaluate if the persister drug combination could more effectively treat or cure patients with PTLDS/chronic Lyme disease.

Pictured: Image of joint histopathology taken from a mouse infected with micro-colony/biofilm-like B. burgdorferi. Read Dr. Zhang’s full paper here.

timothy sellatiTimothy J. Sellati, PH.D. is Chief Scientific Officer at Global Lyme Alliance

As GLA’s Chief Scientific Officer, Dr. Sellati leads GLA’s research initiatives to accelerate the development of more effective methods of diagnosis and treatment of Lyme and other tick-borne diseases.

essential oils_lyme disease research

GLA POV: Essential Oils as Treatment Against Lyme Disease

by Mayla Hsu, Ph.D., Director of Research and Science, GLA

Global Lyme Alliance’s Director of Research and Science offers perspective on newly published research on using essential oils to treat Lyme disease


Global Lyme Alliance (GLA)-funded investigator Ying Zhang, Ph.D. (Professor at Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health) details new findings on the effectiveness of certain essential oils to treat Lyme disease; “Identification of Essential Oils with Strong Activity against Stationary Phase Borrelia burgdorferi.”

Persister forms of B. burgdorferi, the bacterium that causes Lyme disease, are dormant or slow-growing, and tolerant of antibiotic treatment. It’s not clear yet whether persister bacteria, immune dysfunction, or some combination of the two is responsible for post-treatment Lyme disease syndrome (PTLDS), in which patients treated with antibiotics continue to suffer symptoms.

The search for novel compounds to kill persister bacteria has led to the discovery that essential oils (EOs), aromatic compounds produced by plants, may be promising. In an article published in Antibiotics, a peer-reviewed journal, scientists led by Dr. Ying Zhang identified 10 EOs that have strong activity against stationary phase B. burgdorferi at a low concentration of 0.1%. The study, underwritten by GLA, found that of the 10 EOs, those of garlic, allspice, and Palmarosa were active at even at 0.05% concentration. In addition, cinnamaldehyde, a major ingredient isolated from cinnamon bark, was active against both stationary phase bacteria as well as replicating B. burgdorferi at a 0.02% concentration.

A stringent test of antimicrobial activity against stationary phase bacteria is the capacity to block subcultured bacteria from growing. This means that after killing bacteria in culture with the inhibitor, a small amount of that culture is transferred to fresh growth media that lacks the inhibitor. Any regrowth indicates that the inhibitor did not completely kill all bacteria from the original culture. Under these conditions, only garlic and cinnamaldehyde were effective against the regrowth of B. burgdorferi spirochetes subcultured for 21 days.

These results indicate that certain EOs or their ingredients are potent in eliminating persister B. burgdorferi, and should be studied in greater depth to analyze their utility as potential treatments.

ying zhang

Meet the Researcher: Ying Zhang, M.D., Ph.D.


NAME: Ying Zhang, M.D., Ph.D.
TITLE: Professor at Department of Molecular Microbiology and Immunology
INSTITUTION: Johns Hopkins Bloomberg School of Public Health

Dr. Zhang’s research interests are focused on antibiotic resistance, bacterial persistence, and development of more effective treatments for a wide variety of persistent bacterial infections, including tuberculosis (TB). His group has identified persistence mechanisms in important bacterial pathogens including  M. tuberculosis, E. coli, S. aureus, and Borrelia. In addition, his group identified genes and pathways important for L-form bacteria formation. Recently he has been working on the challenging problem of persistent Lyme disease. Dr. Zhang’s group has identified a variety of FDA-approved drugs as well as some essential oils that are more effective in killing Borrelia burgdorferi persisters in vitro than the current Lyme antibiotics. Thanks in part to a GLA-funded grant, and in collaboration with colleagues, his group is evaluating promising drug candidates, including drug combinations and active essential oils in animal models for more effective treatment of Lyme disease and its co-infections.

Drs Janakiram Seshu_Ying Zhang_Research Symposium 2017
Drs Janakiram Seshu and Ying Zhang at GLA Lyme Disease Research Symposium 2017

GLA: What motivated you to focus on Lyme and tick-borne disease research?

YZ: In 2009, we published a paper on the molecular basis of E. coli L-forms (a type of persister bacteria), when I got a call from GLA’s Chairman Rob Kobre asking me for help with persistent Lyme disease. Rob asked me if I would be interested in studying Borrelia L-forms as persisters that may be related to persistent Lyme disease. I said yes, and the rest is history.

As I learned more about the great suffering caused by chronic Lyme disease, also known as Post-Treatment Lyme Disease Syndrome (PTLDS), that so far has no cure, I became more attracted to the mysterious features of the spirochete bacteria and its ability to cause persistent infections. It is an important aspect of the scientific challenge that has eluded us so far. Seeing so many people suffering from such a horrible disease has motivated me to find a more effective cure for chronic Lyme.

GLA: What discovery has been most gratifying?

ying zhang
GLA Board Member Norma Russo with Dr. Zhang at GLA Lyme Disease Research Symposium 2017

YZ: The most gratifying discovery is the identification of Borrelia persister drugs and mechanisms and the persister drug combination approach that more effectively eradicates Borrelia persisters in vitro. We are currently testing different drug combinations in vitro as well as in vivo in animal models. Moreover, we found some essential oils such as oregano, cinnamon bark, and clove bud, and garlic to be highly active against Borrelia persisters and especially against biofilm forms. The active essential oils are very interesting as they are natural products. However, in vivo testing including the dosing schedule, PK, and toxicity and efficacy in killing Borrelia in animal models will have to be done properly before subsequent human studies. I understand some patients are very sick and are desperate to try these on an anecdotal basis. Nevertheless, proper clinical trials will have to be conducted. In addition, we are working on a project that evaluates Borrelia persister antigens for improved diagnosis of Lyme disease, and preliminary results look encouraging.

GLA: Are you confident we’ll find a cure?   

YZ: First, “cure” is a relative term. Because of the heterogeneity and complexity of PTLDS, it is challenging to develop a regimen that will be effective for all such patients. However, based on encouraging in vitro data and the persister drug PZA principle as exemplified in TB treatment, more effective drug combinations for persistent Lyme disease will be developed. This means that at least some segments of persistent Lyme patients can be cured more consistently. However, funding for evaluating drug regimens and for new clinical trials is critically needed. In addition to persister drug regimens, host directed therapy (HDT) improving host immune function will also be important for a more effective cure. We are at a critical juncture and are encouraged by recent interest from the U.S. Department of Health and Human Services in Lyme disease. So I would say to chronic Lyme sufferers, do not give up! There is hope.

GLA-funded research grants with Dr. ZHANG include:

  • “High Activity of Selective Essential Oils Against Borrelia persisters” (2017-18)
  • “Persister Antibodies in PTLDS Patients?” (2016-17)
  • “Optimal Drug Combinations Targeting Bb Persisters for Improved Treatment of Lyme Disease” (2015-16)
  • “Targeting Dormant Bb Persisters for Improved Treatment of Chronic and Persistent Lyme” (2013-14)
  • “Identified Borrelia burgdorferi L-form specific Proteins (ie: Persisters) for Development of New Diagnostics, Vaccines and Also Drugs Targeting L-Form Borrelia” (2011-12)


  1. Identification of Novel Activity against Borrelia burgdorferi Persisters using an FDA Approved Drug Library. Emerging Microbes and Infections Jie Feng, Ting Wang, Wanliang Shi, Shuo Zhang, David Sullivan, Paul G. Auwaerter, Zhang Y (2014). Nature Publishing Group), July 2, 2014. 3, e49; doi:10.1038/emi.2014.53
  2. Drug Combinations against Borrelia burgdorferi Persisters In Vitro: Eradication Achieved by Using Daptomycin, Cefoperazone and Doxycycline Jie Feng, Paul G. Auwaerter, Zhang Y (2015). PLoS One, 2015 Mar 25;10(3):e0117207. doi: 10.1371/journal.pone.0117207
  3. Identification of Additional Anti-Persister Activity against Borrelia burgdorferi from an FDA Drug Library Jie Feng, Megan Weitner, Wanliang Shi, Shuo Zhang, David Sullivan, Zhang Y (2015). Antibiotics, 4(3), 397-410; doi:10.3390/antibiotics4030397
  4. Persister Mechanisms in Borrelia burgdorferi: Implications for Improved Intervention. Emerging Microbes & Infections Jie Feng, Wanliang Shi, Shuo Zhang, Zhang Y (2015)., 4, e51; doi:10.1038/emi.2015.51 https://www.nature.com/articles/emi201551
  5. Eradication of Biofilm-like Microcolony Structures of Borrelia burgdorferi by Daunomycin and Daptomycin but not Mitomycin C in Combination with Doxycycline and Cefuroxime Jie Feng, Megan Weitner, Wanliang Shi, Shuo Zhang, and Zhang Y (2016).. Frontiers in Microbiology, doi: 10.3389/fmicb.2016.00062. https://www.frontiersin.org/articles/10.3389/fmicb.2016.00062/full
  6. A drug combination screen with FDA-library drugs identifies agents active against amoxicillin-induced round bodies of Borrelia burgdorferi persisters Jie Feng, Wanliang Shi, Shuo Zhang, David Sullivan, Paul G. Auwaerter, Zhang Y (2016. Frontiers in Microbiology, 23 May 2016  http://dx.doi.org/10.3389/fmicb.2016.00743
  7. Ceftriaxone Pulse Dosing Fails to Eradicate Biofilm-like Microcolony B. burgdorferi Persisters Which Are Sterilized by Daptomycin/Doxycycline/Cefuroxime without Pulse Dosing Jie Feng, Shuo Zhang, Wanliang Shi, and Zhang Y (2016).. Frontiers in Microbiology, 04 November 2016  http://dx.doi.org/10.3389/fmicb.2016.01744
  8. Selective Essential Oils from Spice or Culinary Herbs Have High Activity against Stationary Phase and Biofilm Borrelia burgdorferi Jie Feng, Shuo Zhang, Wanliang Shi, Nevena Zubcevik, Judith Miklossy, and Ying Zhang (2017).. Front. Med., 11 October 2017 | https://doi.org/10.3389/fmed.2017.00169 

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