BACKGROUND: Mycobacterium avium subsp. paratuberculosis (MAP), the agent of Johne's disease in cattle, is a facultative intracellular bacterium that is dependent on ferric iron for its survival and replication. Gallium (Ga), a trivalent semimetal that shares many similarities with ferric iron and functions as an iron mimic has been shown to have in vitro antimicrobial activity against several microorganisms, including MAP. OBJECTIVES: (1) To investigate the antimicrobial activity of Ga in calves experimentally infected with MAP; and (2) to monitor for potential adverse effects of Ga on calf health. ANIMALS: Twelve Holstein calves. METHODS: Randomized blind controlled experiment. Beginning at 10 days of age (study day 1), the experimental calves (n = 6) were treated with 20 mg/kg gallium nitrate daily for 45 days. On study days 4 and 5, all calves were challenged with a PO dose of a live field strain MAP. Treated calves were monitored daily for adverse effects. Calves were euthanized on study day 100, and 29 tissue samples and 1 fecal sample were collected from each calf. Samples were cultured for MAP by MGIT liquid culture system, Herrold's Egg Yolk Medium culture, or both. RESULTS: No adverse effects were observed in the treated calves. Treatment was associated with a significant reduction in MAP tissue burden when compared with control calves (P = .017). CONCLUSIONS AND CLINICAL RELEVANCE: Chemoprophylactic treatment of calves with Ga before and during the period of high susceptibility decreased MAP tissue colonization in experimentally infected neonatal calves.
BACKGROUND:Mycobacterium avium subsp. paratuberculosis (MAP), the agent of Johne's disease in cattle, is a facultative intracellular bacterium that is dependent on ferric iron for its survival and replication. Gallium (Ga), a trivalent semimetal that shares many similarities with ferric iron and functions as an iron mimic has been shown to have in vitro antimicrobial activity against several microorganisms, including MAP. OBJECTIVES: (1) To investigate the antimicrobial activity of Ga in calves experimentally infected with MAP; and (2) to monitor for potential adverse effects of Ga on calf health. ANIMALS: Twelve Holstein calves. METHODS: Randomized blind controlled experiment. Beginning at 10 days of age (study day 1), the experimental calves (n = 6) were treated with 20 mg/kg gallium nitrate daily for 45 days. On study days 4 and 5, all calves were challenged with a PO dose of a live field strain MAP. Treated calves were monitored daily for adverse effects. Calves were euthanized on study day 100, and 29 tissue samples and 1 fecal sample were collected from each calf. Samples were cultured for MAP by MGIT liquid culture system, Herrold's Egg Yolk Medium culture, or both. RESULTS: No adverse effects were observed in the treated calves. Treatment was associated with a significant reduction in MAP tissue burden when compared with control calves (P = .017). CONCLUSIONS AND CLINICAL RELEVANCE: Chemoprophylactic treatment of calves with Ga before and during the period of high susceptibility decreased MAP tissue colonization in experimentally infected neonatalcalves.
Authors: Francesca Sampieri; Fabio A Vannucci; Andrew L Allen; Nicola Pusterla; Aphroditi J Antonopoulos; Katherine R Ball; Julie Thompson; Patricia M Dowling; Don L Hamilton; Connie J Gebhart Journal: Can J Vet Res Date: 2013-10 Impact factor: 1.310
Authors: Luísa C S Antunes; Francesco Imperi; Fabrizia Minandri; Paolo Visca Journal: Antimicrob Agents Chemother Date: 2012-09-10 Impact factor: 5.191
Authors: Mitchell G Thompson; Vu Truong-Le; Yonas A Alamneh; Chad C Black; Jeff Anderl; Cary L Honnold; Rebecca L Pavlicek; Rania Abu-Taleb; Matthew C Wise; Eric R Hall; Eric J Wagar; Eric Patzer; Daniel V Zurawski Journal: Antimicrob Agents Chemother Date: 2015-08-03 Impact factor: 5.191