TY - JOUR
T1 - In vitro antibacterial activity and in vivo efficacy of hydrated clays on Mycobacterium ulcerans growth
AU - Adusumilli, Sarojini
AU - Haydel, Shelley
N1 - Funding Information:
This research was supported by Public Health Service grant AT004690 awarded to SEH from the NIH National Center for Complementary and Alternative Medicine. We thank Dr. Pamela Small from the University of Tennessee for providing the M. ulcerans strain 1615 and Jacquelyn Kilbourne, Jason Maarsingh, and Randy Boyles for assistance with animal experiments.
Publisher Copyright:
© 2016 Adusumilli and Haydel.
PY - 2016/1/30
Y1 - 2016/1/30
N2 - Background: Buruli ulcer, caused by Mycobacterium ulcerans, is a localized skin lesion that can progress to extensive ulceration and necrosis if left untreated. Unpublished studies of hydrated clays for therapeutic, topical treatment of Buruli ulcer suggest that specific clay mineral products may have beneficial effects on wound healing. In this study, we evaluated the in vitro antibacterial activity of a panel of clay mixtures and their derivative leachates against M. ulcerans and assessed the in vivo efficacy of topically-applied, hydrated clays on Buruli ulcer progression in mice infected with M. ulcerans. Methods: M. ulcerans 1615 was incubated with 10 % suspensions of CB07, CB08, CB09, CB10, and BY07 clay mixtures, and survival was determined over 28 days. For animal experiments, we examined the effect of topical hydrated clay therapy on Buruli ulcer progression in vivo in mouse tails subcutaneously infected with M. ulcerans 1615. Results: The CB07, CB08, and CB09 clays exhibited bactericidal activity against M. ulcerans after 7, 14, 21, and 28 days of incubation. In contrast, clay leachates exhibited inhibitory, bacteriostatic effects on M. ulcerans growth in vitro. After establishing an ulcerative M. ulcerans infection for three months, ulcerated regions of the tails were treated once daily (five consecutive days per week) for 22 days with hydrated CB09 clay poultices. Mice in the clay treatment group exhibited healing as assessed by gross morphological changes and a reduction in M. ulcerans present in the wounds. Conclusions: These data reveal that specific clays exhibit in vitro bactericidal activity against M. ulcerans and that hydrated clay poultices may offer a complementary and integrative strategy for topically treating Buruli ulcer disease.
AB - Background: Buruli ulcer, caused by Mycobacterium ulcerans, is a localized skin lesion that can progress to extensive ulceration and necrosis if left untreated. Unpublished studies of hydrated clays for therapeutic, topical treatment of Buruli ulcer suggest that specific clay mineral products may have beneficial effects on wound healing. In this study, we evaluated the in vitro antibacterial activity of a panel of clay mixtures and their derivative leachates against M. ulcerans and assessed the in vivo efficacy of topically-applied, hydrated clays on Buruli ulcer progression in mice infected with M. ulcerans. Methods: M. ulcerans 1615 was incubated with 10 % suspensions of CB07, CB08, CB09, CB10, and BY07 clay mixtures, and survival was determined over 28 days. For animal experiments, we examined the effect of topical hydrated clay therapy on Buruli ulcer progression in vivo in mouse tails subcutaneously infected with M. ulcerans 1615. Results: The CB07, CB08, and CB09 clays exhibited bactericidal activity against M. ulcerans after 7, 14, 21, and 28 days of incubation. In contrast, clay leachates exhibited inhibitory, bacteriostatic effects on M. ulcerans growth in vitro. After establishing an ulcerative M. ulcerans infection for three months, ulcerated regions of the tails were treated once daily (five consecutive days per week) for 22 days with hydrated CB09 clay poultices. Mice in the clay treatment group exhibited healing as assessed by gross morphological changes and a reduction in M. ulcerans present in the wounds. Conclusions: These data reveal that specific clays exhibit in vitro bactericidal activity against M. ulcerans and that hydrated clay poultices may offer a complementary and integrative strategy for topically treating Buruli ulcer disease.
KW - Antibacterial
KW - Buruli ulcer
KW - Clays
KW - In vivo
KW - Mycobacterium ulcerans
KW - Therapeutic
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U2 - 10.1186/s12906-016-1020-5
DO - 10.1186/s12906-016-1020-5
M3 - Article
C2 - 26833071
AN - SCOPUS:84956943700
SN - 1472-6882
VL - 16
JO - BMC Complementary and Alternative Medicine
JF - BMC Complementary and Alternative Medicine
IS - 1
M1 - 40
ER -