Source: Evaluation of in-vitro antibiotic susceptibility of different morphological forms of Borrelia burgdorferi
Background: Lyme disease is a tick-borne illness caused by the spirochete Borrelia burgdorferi. Although antibiotic therapy is usually effective early in the disease, relapse may occur when administration of antibiotics is discontinued. Studies have suggested that resistance and recurrence of Lyme disease might be due to formation of different morphological forms of B. burgdorferi, namely round bodies (cysts) and biofilm-like colonies. Better understanding of the effect of antibiotics on all morphological forms of B. burgdorferi is therefore crucial to provide effective therapy for Lyme disease.
Methods: Three morphological forms of B. burgdorferi (spirochetes, round bodies, and biofilm-like colonies) were generated using novel culture methods. Minimum inhibitory concentration and minimum bactericidal concentration of five antimicrobial agents (doxycycline, amoxicillin, tigecycline, metronidazole, and tinidazole) against spirochetal forms of B. burgdorferi were evaluated using the standard published microdilution technique. The susceptibility of spirochetal and round body forms to the antibiotics was then tested using fluorescent microscopy (BacLight™ viability staining) and dark field microscopy (direct cell counting), and these results were compared with the microdilution technique. Qualitative and quantitative effects of the antibiotics against biofilm-like colonies were assessed using fluorescent microscopy and dark field microscopy, respectively.
Results: Doxycycline reduced spirochetal structures ~90% but increased the number of round body forms about twofold. Amoxicillin reduced spirochetal forms by ~85%–90% and round body forms by ~68%, while treatment with metronidazole led to reduction of spirochetal structures by ~90% and round body forms by ~80%. Tigecycline and tinidazole treatment reduced both spirochetal and round body forms by ~80%–90%. When quantitative effects on biofilm-like colonies were evaluated, the five antibiotics reduced formation of these colonies by only 30%–55%. In terms of qualitative effects, only tinidazole reduced viable organisms by ~90%. Following treatment with the other antibiotics, viable organisms were detected in 70%–85% of the biofilm-like colonies.
Conclusion: Antibiotics have varying effects on the different morphological forms of B. burgdorferi. Persistence of viable organisms in round body forms and biofilm-like colonies may explain treatment failure and persistent symptoms following antibiotic therapy of Lyme disease. (Emphasis Added.)
Read as (what us “Lymies” have known for years): The bacteria change forms to evade the different classes of antibiotics, and none of the antibiotics they researched had greater than a 55% success rate at eradicating Lyme disease’s biofilm form. Rifampin supposedly treats the cyst form, I wonder why they didn’t test that? Granted, all of this was done in-vitro, and sometimes things react differently when in the human body.
First off, I have to say this makes me feel very good about my LLMD suggesting that I go on Tindamax after the Rifampin! If the Rifampin is killing the round/cyst form right now, and this study shows that Tindamax (tinidazole) eliminated up to 90% of both forms of the Lyme bacteria… Goodness, I could be cured at that rate! (Well, unless they’re making biofilms… The jury is still out on how to completely get rid of those.) I’m also impressed that tinidazole kills even more than its close-cousin Flagyl (metronidazole), because we all know how well Flagyl works for neuroborreliosis. From what I’ve looked at, Tindamax also has less side effects.
At first I was shocked to read Doxycycline actually increased the round/cyst form of the Lyme bacteria, but then I remembered Doxycycline does not kill, it only stops the replication process. So if the bacteria cannot reproduce one way, they will just morph and produce in whatever way enables them to survive. This study actually proves that.
I think this study was much-needed, and even a bit groundbreaking, if you ask me. But shhhh, “chronic Lyme doesn’t exist,” you know…
♥ a rainbow at night
[ETA: This makes more sense today, so I had to edit a few things. I got confused into thinking that the biofilm and cyst form were the same thing, but now I remember from the Under Our Skin documentary that the biofilms are those little clusters of spirochetes stuck together in that gel-like substance. You can go here to read further explanation.]