C Budd1, C Flanagan2, A Gillett3, J Hanger4, J J Loader4, M Govendir1. 1. Sydney School of Veterinary Science The University of Sydney, Sydney, New South Wales, Australia. 2. Port Macquarie Koala Hospital, Port Macquarie, New South Wales, Australia. 3. Australia Zoo Wildlife Hospital, Beerwah, Queensland, Australia. 4. Endeavour Veterinary Ecology, Toorbul, Queensland, Australia.
Abstract
OBJECTIVE: Because of limited availability of chloramphenicol to veterinary suppliers, a preliminary study was performed to predict whether an analogue, florfenicol, is an efficacious treatment for chlamydiosis in koalas. METHODS: Florfenicol was administered to koalas with naturally occurring chlamydiosis at 20 mg/kg SC (n = 3) and at 5 mg/kg (n = 3) and 10 mg/kg (n = 3) IV. The estimated areas under the plasma concentration versus time curves (AUC) were compared with the minimum inhibitory concentration to inhibit Chlamydia pecorum. Clinical data were also examined from field trials conducted on koalas (n = 19) with naturally occurring chlamydiosis and treated with florfenicol at a range of dosages (5-20 mg/kg SC and 6-15 mg/kg IV). Florfenicol binding to proteins in plasma was also determined. RESULTS: Florfenicol was not detectable in plasma 24 h post-administration at 20 mg/kg SC. The estimated AUC0-24 h following administration at 10 mg/kg IV suggests florfenicol might be effective against Chlamydia spp. via this route. Florfenicol binding to plasma proteins was 13.0% (± 0.30 SEM). After treatment with florfenicol in field trials, 5 of 19 koalas (26%) were released without further treatment, 4 with no long-term follow-up; 6 (32%) required additional treatment with chloramphenicol to resolve chlamydiosis; 7 (36%) failed to clinically improve, of which 3 had clinical signs and/or necropsy findings suggestive of antibiotic-related gastrointestinal dysbiosis; another koala died within minutes of florfenicol administered IV at 7 mg/kg. CONCLUSION: When administered at dosages tolerable in the field, florfenicol is a problematic treatment for chlamydiosis based on equivocal outcomes and plasma concentrations below those that inhibit the pathogen.
OBJECTIVE: Because of limited availability of chloramphenicol to veterinary suppliers, a preliminary study was performed to predict whether an analogue, florfenicol, is an efficacious treatment for chlamydiosis in koalas. METHODS:Florfenicol was administered to koalas with naturally occurring chlamydiosis at 20 mg/kg SC (n = 3) and at 5 mg/kg (n = 3) and 10 mg/kg (n = 3) IV. The estimated areas under the plasma concentration versus time curves (AUC) were compared with the minimum inhibitory concentration to inhibit Chlamydia pecorum. Clinical data were also examined from field trials conducted on koalas (n = 19) with naturally occurring chlamydiosis and treated with florfenicol at a range of dosages (5-20 mg/kg SC and 6-15 mg/kg IV). Florfenicol binding to proteins in plasma was also determined. RESULTS:Florfenicol was not detectable in plasma 24 h post-administration at 20 mg/kg SC. The estimated AUC0-24 h following administration at 10 mg/kg IV suggests florfenicol might be effective against Chlamydia spp. via this route. Florfenicol binding to plasma proteins was 13.0% (± 0.30 SEM). After treatment with florfenicol in field trials, 5 of 19 koalas (26%) were released without further treatment, 4 with no long-term follow-up; 6 (32%) required additional treatment with chloramphenicol to resolve chlamydiosis; 7 (36%) failed to clinically improve, of which 3 had clinical signs and/or necropsy findings suggestive of antibiotic-related gastrointestinal dysbiosis; another koala died within minutes of florfenicol administered IV at 7 mg/kg. CONCLUSION: When administered at dosages tolerable in the field, florfenicol is a problematic treatment for chlamydiosis based on equivocal outcomes and plasma concentrations below those that inhibit the pathogen.
Authors: Michaela D J Blyton; Rochelle M Soo; Desley Whisson; Karen J Marsh; Jack Pascoe; Mark Le Pla; William Foley; Philip Hugenholtz; Ben D Moore Journal: Anim Microbiome Date: 2019-08-21
Authors: Emma Peel; Yuanyuan Cheng; Julianne T Djordjevic; Denis O'Meally; Mark Thomas; Michael Kuhn; Tania C Sorrell; Wilhelmina M Huston; Katherine Belov Journal: PLoS One Date: 2021-04-14 Impact factor: 3.240