Friday, June 28, 2019

Bartonella persisters and daptomycin: two for the price of one?


While Lyme persistence I denied for political reasons the persistence of other human zoonotic pathogens is recognized. 

I have seen two cases of brucellosis recently and Brucella is recognized as a persistent bacterium, perhaps impossible to eradicate, at least with currently used and/or recommended therapy.

B. abortus is one of several well-known human pathogens of the genus, the one which may be acquired via tick bites.

Brucellosis can be acquired by consumption of uncooked meat and raw milk. I don’t understand the fad of drinking unpasteurized milk, a potentially deadly fad.

Brucellosis may cause numerous untoward clinical syndromes many of which similar to those seen with chronic Lyme.

Bartonella, especially B. henselae is a well known tickborne pathogen also known to exhibit persistence. The bacteria, a fastidious (difficult to culture) gram negative rod is an obligate (facultative) intracellular gram-negative bacteria associated with well described clinical syndromes, discussed elsewhere. Spotty medical literature supports the notion that Bartonella infection is clinically persistent.

Biologically, Bartonella are the only bacteria which may reside in red blood cells. The only other RBC pathogens are malaria and babesia species. Specific biological features, a protected niche and the discovery of stationary forms provide an ample narrative of fact and biological plausibility for persistence. 

The primary home for these bacteria is not RBCs but the endothelial cells that line blood vessels. This is why bartonellosis causes well known vasculitis syndromes. 

Zhang, a prolific publisher, should now be a star at JHH published about Bartonella persisters in antibiotics April. Again, daptomycin is the star.   Daptomycin has the best activity against stationary (persister) forms. Only aminoglycosides, e.g gentamycin are competitive.  In my experience, gentamycin may eradicate clinical infection, but not consistently. Complex multidrug regimens are frequently recommended for Bartonellosis, perhaps this is unnecessary.

This study added to others vis-à-vis Lyme raises the clinical (preclinical) question. Should patients with chronic illness caused by Lyme and Bartonella be treated with combination IV therapy, Rocephin, Doxycycline and Daptomycin earlier rather than later in the course of treatment?

From an Evidenced Based Medicine approach this is anathema,  such therapies can only be recommended after randomized clinical trials, peer reviewed and published.

Such studies are perhaps decades away.  Currently the political divide make diagnosis of Lyme nearly impossible, let alone coinfections.

The preclinical approach allows for empiric use of the therapy without waiting for IDSA approval, which may or may not ever come.

This concept of applying preclinical data (translational medicine) is well developed and well used in the field of oncology. Of course, cancer is considered a serious disease (and Lyme isn’t?).

Those of us in the alternative universe of Lyme disease are accustomed to very long-term antibiotics, including IV ones.  In this world, the use of these 3 IV drugs sounds reasonable. In the other world we are no strangers to cocktail therapy and IV therapy.  In the IDSA/CDC world of doxy for 3 weeks even discussion of this idea is heresy or treasonous, if such things apply in medicine (apparently, they do).

Treating chronic Lyme through the other world approach is very complicated, lengthy and expensive. This sort of preclinical information should be considered in lengthy, informed consent discussions with patients.  

1 comment:

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