The Crohnie

Another piece of research which establishes the anti-paratuberculosis antibiotic activity of molecules which are currently thought to have an immuno-suppressant effect in Crohn’s Disease.

http://www.paratuberculosis.org/pubs/proc9/abst185f_o4.htm

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BACKGROUND:

We have shown that the “immuno-modulators” methotrexate and 6-MP and the “anti-inflammatory” 5-ASA inhibit MAP growth (www.PLoSONE.org) and concluded that their most plausible mechanism of action in several idiopathic diseases is as antiMAP antibiotics. Thalidomide is an “immunomodulator” used in multiple “auto-immune” and “inflammatory” diseases and the mycobacterial diseases leprosy and tuberculosis. We now test the hypothesis that thalidomide inhibits MAP growth.

METHODS

Thalidomide (+-) and (+) and (-) and its two components, phthalimide and 1-hydroxy 2,6 piperidine dione (HPD) were evaluated in culture of two strains each of MAP (ATCC 19698 [bovine] & Dominic [human]) and M. avium subspecies avium (ATCC 25291 & 101.) We used a radiometric (14CO2 Bactec(R)) detection system. Inhibition is indicated by “percent decrease in cumulative Growth Index” (%-DcGI) from control.

RESULTS:

Phthalimide has no dose dependent inhibition on any strain. There was no dose dependent inhibition on either M. avium strain with thalidomide or its components. With the two MAP strains, there is dose dependent inhibition with thalidomide (+1); Dominic (31%-DcGI) and ATCC 19698 (26%-DcGI) at 64microg/ml. Thalidomide (+) is more inhibitory than (-). HPD is, on a weight for weight basis, the most inhibitory agent evaluated; Dominic (46%-DcGI) and ATCC 19698 (44%-DcGI at 64microg/ml)

CONCLUSIONS:

We show in vitro heretofore-undescribed inhibition of MAP growth by racaemic thalidomide. Thalidomide (+) is more potent than (-). Of thalidomide’s two moieties, phthalimide has no antiMAP activity and HPD is the active component in inhibiting MAP growth. We suggest that since 1942, initially with 5-ASA, the medical profession has unknowingly been treating MAP infections. These data are compatible with our concern that MAP is zoonotic. We conclude that all idiopathic “autoimmune” and “inflammatory” diseases, empirically treated with medications that we show are active against MAP, should now be evaluated for MAP as the etiological agent.

It appears that some Azathioprine and 6-MP, which are used for the treatment of Crohn’s Disease, and whose mechanism of action is currently unknown, have antibiotic activity against Mycobacterium avium subspecies paratuberculosis (MAP).

http://www.paratuberculosis.org/pubs/proc9/abst182f_o6.htm

As noted by the authors, “These data may partially explain the paradoxical response of Crohn’s disease patients infected with M. paratuberculosis to treatment with immunosuppressive thiopurine drugs i.e. they do not worsen with anti-inflammatory treatment as would be expected with a microbial etiologic pathogen.”
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The in vitro susceptibility of human and bovine-origin Mycobacterium paratuberculosis to the thiopurine drugs 6-mercaptopurine (6-MP) and azathioprine (AZA) were established using conventional plate counting methods and the MGIT 960 ParaTB culture system. Both 6-MP and AZA had antibacterial activity against M. paratuberculosis; isolates from Crohn’s disease patients tended to be more susceptible than were bovine-origin isolates. Isolates of Mycobacterium avium, used as controls, were generally resistant to both AZA and 6-MP even at high concentrations (>=64.0 microg/mL). Among rapidly growing mycobacteria, M. phlei was susceptible to 6-MP and AZA whereas M. smegmatis strains were not. AZA and 6-MP limited the growth of, but did not kill, M. paratuberculosis in a dose-dependent manner. Anti-inflammatory drugs in the sulfonamide family (sulfapyridine, sulfasalazine, and 5-amino- salycilic acid (mesalamine)) had little or no antibacterial activity against M. paratuberculosis. The conventional antibiotics azithromycin and ciprofloxacin (CPX) used as control drugs were bactericidal for M. paratuberculosis, exerting their killing effects on the organism relatively quickly. Simultaneous exposure of M. paratuberculosis to 6- MP and CPX resulted in significantly higher CFUs as compared to use of CPX alone. These data may partially explain the paradoxical response of Crohn’s disease patients infected with M. paratuberculosis to treatment with immunosuppressive thiopurine drugs i.e. they do not worsen with anti-inflammatory treatment as would be expected with a microbial etiologic pathogen. These findings also should influence the design of therapeutic trials to evaluate antibiotic treatments of Crohn’s disease: azathioprine drugs may confound interpretation of data on therapeutic responses both antibiotic-treated and control groups.

On the action of 5-amino-salicylic acid and sulfapyridine on M. avium including subspecies paratuberculosis.
Greenstein RJ, Su L, Shahidi A, Brown ST.
PLoS ONE. 2007 Jun 13;2(6):e516

http://www.ncbi.nlm.nih.gov/pubmed/17565369

Full Text

Abstract

BACKGROUND: Introduced in 1942, sulfasalazine (a conjugate of 5-aminosalicylic acid (5-ASA) and sulfapyridine) is the most prescribed medication used to treat “inflammatory” bowel disease (IBD.) Although controversial, there are increasingly compelling data that Mycobacterium avium subspecies paratuberculosis (MAP) may be an etiological agent in some or all of IBD. We have shown that two other agents used in the therapy of IBD (methotrexate and 6-MP) profoundly inhibit MAP growth. We concluded that their most plausible mechanism of action is as antiMAP antibiotics. We herein hypothesize that the mechanism of action of 5-ASA and/or sulfapyridine may also simply be to inhibit MAP growth. METHODOLOGY: The effect on MAP growth kinetics by sulfasalazine and its components were evaluated in bacterial culture of two strains each of MAP and M. avium, using a radiometric ((14)CO(2) BACTEC(R)) detection system that quantifies mycobacterial growth as arbitrary “growth index units” (GI). Efficacy data are presented as “percent decrease in cumulative GI” (%-DeltacGI). PRINCIPAL FINDINGS: There are disparate responses to 5-ASA and sulfapyridine in the two subspecies. Against MAP, 5-ASA is inhibitory in a dose-dependent manner (MAP ATCC 19698 46%-DeltacGI at 64 microg/ml), whereas sulfapyridine has virtually no effect. In contrast, against M. avium ATCC 25291, 5-ASA has no effect, whereas sulfapyridine (88%-DeltacGI at 4 microg/ml) is as effective as methotrexate, our positive control (88%-DeltacGI at 4 microg/ml). CONCLUSIONS: 5-ASA inhibits MAP growth in culture. We posit that, unknowingly, the medical profession has been treating MAP infections since sulfasalazine’s introduction in 1942. These observations may explain, in part, why MAP has not previously been identified as a human pathogen. We conclude that henceforth in clinical trials evaluating antiMAP agents in IBD, if considered ethical, the use of 5-ASA (as well as methotrexate and 6-MP) should be excluded from control groups.

On the action of methotrexate and 6-mercaptopurine on M. avium subspecies paratuberculosis.
Greenstein RJ, Su L, Haroutunian V, Shahidi A, Brown ST.
PLoS ONE. 2007 Jan 24;2(1):e161

http://www.ncbi.nlm.nih.gov/pubmed/17252054

Full Text

Abstract

BACKGROUND: Clinical improvement in inflammatory bowel disease (IBD) treated with methotrexate and 6-mercaptopurine (6-MP) is associated with a decrease in pro-inflammatory cytokines. This has been presumed to indicate the mechanism of action of methotrexate and 6-MP. Although controversial, there are increasingly compelling data that Mycobacterium avium subspecies paratuberculosis (MAP) may be an etiological agent in some or all of IBD. We hypothesized that the clinical efficacy of methotrexate and 6-MP in IBD may be to simply inhibit the growth of MAP. METHODOLOGY: The effect on MAP growth kinetics by methotrexate and 6-MP were evaluated in cell culture of two strains each of MAP and M. avium using a radiometric ((14)CO(2) BACTEC detection system that quantifies mycobacterial growth as arbitrary “growth index units” (GI). Efficacy data are presented as “percent decrease in cumulative GI” (% -DeltacGI). PRINCIPAL FINDINGS: The positive control antibiotic (clarithromycin) has >or=85% -DeltacGI at a concentration of 0.5 microg/ml. The negative control (ampicillin) has minimal inhibition at 64 microg/ml. MAP ATCC 19698 shows >or=80% -DeltacGI for both agents by 4 microg/ml. With the other three isolates, although more effective than ampicillin, 6-MP is consistently less effective than methotrexate. CONCLUSIONS: We show that methotrexate and 6-MP inhibit MAP growth in vitro. Each of the four isolates manifests different % -DeltacGI. These data are compatible with the hypothesis that the clinical improvement in patients with IBD treated with methotrexate and 6-MP could be due to treating a MAP infection. The decrease in pro-inflammatory cytokines, thought to be the primary mechanism of action, may simply be a normal, secondary, physiological response. We conclude that henceforth, in clinical studies that evaluate the effect of anti-MAP agents in IBD, the use of methotrexate and 6-MP should be excluded from any control groups.

On the Action of Cyclosporine A, Rapamycin and Tacrolimus on M. avium Including Subspecies paratuberculosis
Greenstein RJ, Su L, Juste RA, Brown ST.
PLoS ONE. 2008 Jun 25;3(6):e2496

http://www.ncbi.nlm.nih.gov/pubmed/18575598

Full Text

Abstract

BACKGROUND: Mycobacterium avium subspecies paratuberculosis (MAP) may be zoonotic. Recently the “immuno-modulators” methotrexate, azathioprine and 6-MP and the “anti-inflammatory” 5-ASA have been shown to inhibit MAP growth in vitro. We concluded that their most plausible mechanism of action is as antiMAP antibiotics. The “immunosuppressants” Cyclosporine A, Rapamycin and Tacrolimus (FK 506) treat a variety of “autoimmune” and “inflammatory” diseases. Rapamycin and Tacrolimus are macrolides. We hypothesized that their mode of action may simply be to inhibit MAP growth. METHODOLOGY: The effect on radiometric MAP (14)CO(2) growth kinetics of Cyclosporine A, Rapamycin and Tacrolimus on MAP cultured from humans (Dominic & UCF 4) or ruminants (ATCC 19698 & 303) and M. avium subspecies avium (ATCC 25291 & 101) are presented as “percent decrease in cumulative GI” (%-DeltacGI.) PRINCIPAL FINDINGS: The positive control clofazimine has 99%-DeltacGI at 0.5 microg/ml (Dominic). Phthalimide, a negative control has no dose dependent inhibition on any strain. Against MAP there is dose dependent inhibition by the immunosuppressants. Cyclosporine has 97%-DeltacGI by 32 microg/ml (Dominic), Rapamycin has 74%-DeltacGI by 64 microg/ml (UCF 4) and Tacrolimus 43%-DeltacGI by 64 microg/ml (UCF 4) CONCLUSIONS: We show heretofore-undescribed inhibition of MAP growth in vitro by “immunosuppressants;” the cyclic undecapeptide Cyclosporine A, and the macrolides Rapamycin and Tacrolimus. These data are compatible with our thesis that, unknowingly, the medical profession has been treating MAP infections since 1942 when 5-ASA and subsequently azathioprine, 6-MP and methotrexate were introduced in the therapy of some “autoimmune” and “inflammatory” diseases.