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. 2017 Nov 21;13(1):345.
doi: 10.1186/s12917-017-1270-6.

Opportunities for topical antimicrobial therapy: permeation of canine skin by fusidic acid

Sian-Marie Frosini  1 , Ross Bond  2 , Anette Loeffler  2 , Jo Larner  3
Affiliations

Opportunities for topical antimicrobial therapy: permeation of canine skin by fusidic acid

Sian-Marie Frosini et al. BMC Vet Res. .

Abstract

Background: Staphylococcal infection of the canine epidermis and hair follicle is amongst the commonest reasons for antimicrobial prescribing in small animal veterinary practice. Topical therapy with fusidic acid (FA) is an attractive alternative to systemic therapy based on low minimum inhibitory concentrations (MICs, commonly <0.03 mg/l) documented in canine pathogenic staphylococci, including strains of MRSA and MRSP (methicillin-resistant Staphylococcus aureus and S. pseudintermedius). However, permeation of canine skin by FA has not been evaluated in detail. This study aimed to define the degree and extent of FA permeation in canine skin in vitro from two sites with different hair follicle density following application of a licensed ophthalmic formulation that shares the same vehicle as an FA-betamethasone combination product approved for dermal application in dogs. Topical FA application was modelled using skin held in Franz-type diffusion cells. Concentrations of FA in surface swabs, receptor fluid, and transverse skin sections of defined anatomical depth were determined using high-performance liquid chromatography and ultraviolet (HPLC-UV) analysis.

Results: The majority of FA was recovered by surface swabs after 24 h, as expected (mean ± SEM: 76.0 ± 17.0%). FA was detected within 424/470 (90%) groups of serial sections of transversely cryotomed skin containing follicular infundibula, but never in 48/48 (100%) groups of sections containing only deeper follicular structures, nor in receptor fluid, suggesting that FA does not permeate beyond the infundibulum. The FA concentration (mean ± SEM) in the most superficial 240 μm of skin was 2000 ± 815 μg/g.

Conclusions: Topically applied FA can greatly exceed MICs for canine pathogenic staphylococci at the most common sites of infection. Topical FA therapy should now be evaluated using available formulations in vivo as an alternative to systemic therapy for canine superficial bacterial folliculitis.

Keywords: Canine; Fusidic acid; Pyoderma; Skin; Topical therapy.

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Conflict of interest statement

Ethics approval

The Royal Veterinary College’s Clinical Research Ethical Review Board endorsed the use of cadaveric canine skin that was donated for this purpose by an approved external laboratory (2016 1651–2-R).

Consent for publication

Not applicable.

Competing interests

The authors’ group has previously received funding from Dechra Veterinary Products (DVP), Shropshire, UK, in support of laboratory research and clinical teaching of undergraduate and postgraduate students.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
Composite image of the histology of the canine compound hair follicle. a Traditional vertical section through the long axis of a compound follicle from epidermis (right) to panniculus adiposus (left). Lines indicate planes of section for corresponding transverse images that define depth of section. b Transverse section at common infundibulum: follicle is lined by stratified squamous keratinising epithelium that recapitulates that of the interfollicular epidermis and contains multiple naked hair fibres. c Transverse section at isthmus: compound follicle comprises a cranial primary hair and a group of (commonly 14–18) secondary hair follicles; each hair shaft is surrounded by root sheaths whose anatomy varies with stage of hair growth. d Transverse section at inferior portion of follicles: presence indicates anagen phase represented by hair fibre surrounded by inner root sheath and glycogen-rich outer root sheath
Fig. 2
Fig. 2
Individual / combined percentage recoveries of FA (mean ± SEM) in skin and swab following 24 h topical application of a 10 mg/g carbomer gel formulation of FA to dorsal and groin skin from healthy Beagle dogs
See this image and copyright information in PMC

References

    1. World Health Organisation. Global Action Plan on Antimicrobial Resistance. 2015. http://www.who.int/antimicrobial-resistance/publications/global-action-p.... Accessed 8 Aug 2016.
    1. Summers JF, Hendricks A, Brodbelt DC. Prescribing practices of primary-care veterinary practitioners in dogs diagnosed with bacterial pyoderma. BMC Vet Res. 2014;10:240. doi: 10.1186/s12917-014-0240-5. - DOI - PMC - PubMed
    1. Loeffler A, Linek M, Moodley A, Guardabassi L, Sung JML, Winkler M, et al. First report of multiresistant, mecA-positive Staphylococcus intermedius in Europe: 12 cases from a veterinary dermatology referral clinic in Germany. Vet Dermatol. 2007;18:412–421. doi: 10.1111/j.1365-3164.2007.00635.x. - DOI - PubMed
    1. Hillier A, Lloyd DH, Weese JS Blondeau JM, Boothe D, Breitschwerdt E, et al. Guidelines for the diagnosis and antimicrobial therapy of canine superficial bacterial folliculitis (antimicrobial guidelines working Group of the International Society for companion animal infectious diseases). Vet Dermatol 2014;25:163-e43. - PubMed
    1. Nesbitt GH. Bacterial diseases. In: Lea & Febiger, editor. Canine and feline dermatology. A systematic approach. Philadelphia: Lippincott Williams and Wilkins; 1983.

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