Rhodotorula mucilaginosa lymphadenitis in an HIV-infected patient

SummaryWe report a case of lymphadenitis due to Rhodotorula mucilaginosa in a man with well-controlled HIV infection. The diagnosis was established microbiologically by positive lymph tissue cultures, and clinically by responses of lymphadenitis to antifungal therapy. The patient was asymptomatic and was treated with itraconazole 200mg orally once daily as an outpatient. Clinical response was evident within three weeks with improvement of lymphadenopathy on serial computed tomography scans. Lymphadenopathy resolved completely after 8 months of itraconazole therapy and had not recurred 9 months after treatment was stopped

On the Action of Methotrexate and 6-Mercaptopurine on M. avium Subspecies paratuberculosis

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” (% −ΔcGI). PRINCIPAL FINDINGS: The positive control antibiotic (clarithromycin) has ≥85% −ΔcGI at a concentration of 0.5 µg/ml. The negative control (ampicillin) has minimal inhibition at 64 µg/ml. MAP ATCC 19698 shows ≥80% −ΔcGI for both agents by 4 µg/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 % −ΔcGI. 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 5-Amino-Salicylic Acid and Sulfapyridine on M. avium including Subspecies paratuberculosis

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

Unanticipated Mycobacterium tuberculosis complex culture inhibition by immune modulators, immune suppressants, a growth enhancer, and vitamins A and D: clinical implications

Background: The development of novel antibiotics to treat multidrug-resistant (MDR) tuberculosis is time-consuming and expensive. Multiple immune modulators, immune suppressants, anti-inflammatories, and growth enhancers, and vitamins A and D, inhibit Mycobacterium avium subspecies paratuberculosis (MAP) in culture. We studied the culture inhibition of Mycobacterium tuberculosis complex by these agents. Methods: Biosafety level two M. tuberculosis complex (ATCC 19015 and ATCC 25177) was studied in radiometric Bactec or MGIT culture. Agents evaluated included clofazimine, methotrexate, 6-mercaptopurine, cyclosporine A, rapamycin, tacrolimus, monensin, and vitamins A and D. Results: All the agents mentioned above caused dose-dependent inhibition of the M. tuberculosis complex. There was no inhibition by the anti-inflammatory 5-aminosalicylic acid, which causes bacteriostatic inhibition of MAP. Conclusions: We conclude that, at a minimum, studies with virulent M. tuberculosis are indicated with the agents mentioned above, as well as with the thioamide 5-propothiouricil, which has previously been shown to inhibit the M. tuberculosis complex in culture. Our data additionally emphasize the importance of vitamins A and D in treating mycobacterial diseases

Positive Control: Methotrexate

<p>%−ΔcGI</p

Negative Control: Intact Sulfasalazine

<p>%−ΔcGI</p

Test Agents: 5-ASA+Sulfapyridine

<p>%−ΔcGI</p

Cumulative GI data when 2.7×10⁴ CFU/vial of MAP ATCC 19698 was inoculated into each Bactec vial.

<p>Each drug dilution was studied in duplicate. Error bars are SD. The positive control is methotrexate, with maximal inhibition by 8 mg/ml. Neither the negative control sulfasalazine, nor sulfapyridine, have any inhibition. Both and 5-ASA alone and in combination with sulfapyridine have dose dependent inhibition.</p