Arsenicicoccus dermatophilus sp. nov., a hypha-forming bacterium isolated from the skin of greater flamingos (Phoenicopterus roseus) with pododermatitis

Dermatophilus-like bacteria were observed in histological examinations of samples of diseased foot skin from greater flamingos (Phoenicopterus roseus) living in zoological gardens in Switzerland. When grown on TSA-SB containing polymyxin B, the bacteria isolated from these skin samples formed hyphae, as is typical for Dermatophilus congolensis, but these bacteria were non-haemolytic. The closest relatives based on 16S rRNA gene sequences were the two members of the genus Arsenicicoccus, Arsenicicoccus bolidensis and Arsenicicoccus piscis. A representative of the isolated strains shared 34.3 % DNA-DNA relatedness with the type strain of A. bolidensis, 32.3 % with the type strain of A. piscis and 34.5 % with the type strain of D. congolensis, demonstrating that these strains do not belong to any of these species. The phenotypic characteristics differed from those of members of the genus Arsenicicoccus as well as from those of D. congolensis. The G+C content of strain KM 894/11(T) was 71.6 mol%. The most abundant fatty acids were iso-C15 : 0, summed feature 3 (including C16 : 1ω7c and/or iso-C15 : 0 2-OH) and C18 : 1ω9c. MK-8(H4) was the predominant menaquinone. Cell-wall structure analysis revealed that the peptidoglycan type was A3γ ll-Dpm-Gly (type A41.1). Based on genotypic and chemotaxonomic characteristics, the isolated strains represent a novel species within the genus Arsenicicoccus, for which the name Arsenicicoccus dermatophilus sp. nov. is proposed. The type strain is KM 894/11(T) ( = DSM 25571(T) = CCUG 62181(T) = CCOS 690(T)), and strain KM 1/12 ( = DSM 25572 = CCUG 62182 = CCOS 691) is a reference strain.

Expression of Foxi3 is regulated by ectodysplasin in skin appendage placodes

BACKGROUND Foxi3 is a member of the large forkhead box family of transcriptional regulators, which have a wide range of biological activities including manifold developmental processes. Heterozygous mutation in Foxi3 was identified in several hairless dog breeds characterized by sparse fur coat and missing teeth. A related phenotype called hypohidrotic ectodermal dysplasia (HED) is caused by mutations in the ectodysplasin (Eda) pathway genes. RESULTS Expression of Foxi3 was strictly confined to the epithelium in developing ectodermal appendages in mouse embryos, but no expression was detected in the epidermis. Foxi3 was expressed in teeth and hair follicles throughout embryogenesis, but in mammary glands only during the earliest stages of development. Foxi3 expression was decreased and increased in Eda loss- and gain-of-function embryos, respectively, and was highly induced by Eda protein in embryonic skin explants. Also activin A treatment up-regulated Foxi3 mRNA levels in vitro. CONCLUSIONS Eda and activin A were identified as upstream regulators of Foxi3. Foxi3 is a likely transcriptional target of Eda in ectodermal appendage placodes suggesting that HED phenotype may in part be produced by compromised Foxi3 activity. In addition to hair and teeth, Foxi3 may have a role in nail, eye, and mammary, sweat, and salivary gland development.