日本科學(xué)家最近發(fā)現(xiàn)一種微藻類新品種,可能會(huì)使人感染,,危及生命,。
這種名叫Prototheca cutis的新水藻是科學(xué)家對(duì)一名日本患者的皮膚樣本進(jìn)行分析后發(fā)現(xiàn)的,他因接觸這種水藻引起感染,,身上出現(xiàn)潰瘍,。研究人員認(rèn)為,除了南極洲以外,,人們可能會(huì)在世界各地的土壤和水里發(fā)現(xiàn)P. cutis,。因?yàn)檫@種微生物的生存能力很強(qiáng),可在經(jīng)過消毒的環(huán)境下(例如加氯消毒)幸存下來,,它們?cè)谖鬯图彝ダ锓毖苌?,農(nóng)村環(huán)境對(duì)它們的生存更加有利。
這名日本患者已經(jīng)被成功治愈,,他是目前已知的唯一一名P. cutis受害者,。但是日本東京帝京大學(xué)的醫(yī)學(xué)真菌學(xué)家、這項(xiàng)研究的領(lǐng)導(dǎo)者槙村浩一認(rèn)為,,最新發(fā)現(xiàn)的這種水藻的行為,,可能跟有害的微藻類一樣。微藻類是在世界各地的水域里發(fā)現(xiàn)的單細(xì)胞有機(jī)體,。
如果真是這樣,,P. cutis將能進(jìn)入傷口(例如通過接觸受污染的水),使人的胳膊,、腿和臉上發(fā)炎,,甚至產(chǎn)生潰瘍。槙村浩一表示,這個(gè)過程非常緩慢,,有時(shí)需要2周或者更長(zhǎng)時(shí)間才能形成潰瘍,。他說,有報(bào)告稱,,在牛,、鹿、狗和貓身上也見過類似的微藻類感染現(xiàn)象,。
在嚴(yán)重情況下,,微藻類感染會(huì)慢慢演變成具有致命風(fēng)險(xiǎn)的敗血癥(細(xì)菌進(jìn)入血液)或者腦膜炎(大腦和脊髓周圍的組織發(fā)炎)。據(jù)該研究說,,身體虛弱的住院患者經(jīng)常會(huì)出現(xiàn)這種情況,。
槙村浩一表示,由于微藻類感染非常罕見,,因此這方面的治療方法并不多,。目前只能用抗真菌藥物進(jìn)行治療。即使水藻不是真菌,,但事實(shí)證明,,抗真菌藥物治愈了近59%的嚴(yán)重的微藻類感染患者的疾病。
他表示,,那些不治身亡的患者的感染情況更加嚴(yán)重,。不過他說,世界上的大部分微藻類“都是無害的”,,這種情況使新發(fā)現(xiàn)的P. cutis成為一種非常重要和具有吸引力的研究對(duì)象,。(生物谷Bioon.com)
生物谷推薦原文出處:
Int J Syst Evol Microbiol DOI:10.1099/ijs.0.016402-0
Prototheca cutis sp. nov., a newly discovered pathogen of protothecosis isolated from inflamed human skin
Kazuo Satoh1,2, Kenji Ooe3, Hirotoshi Nagayama3 and Koichi Makimura1,4
1 Teikyo University Institute of Medical Mycology, Hachioji, Tokyo, Japan
2 Japan Health Sciences Foundation, Chuo-ku, Tokyo, Japan
3 Asahi General Hospital, Asahi, Chiba, Japan
4 Genome Research Center, Graduate School of Medicine and Faculty of Medicine, Teikyo University, Hachioji, Tokyo, Japan
A strain of a novel pathogenic, achlorophyllic alga belonging to the genus Prototheca was isolated from the inflamed skin of a patient with protothecosis in a Japanese hospital. The pathogen was detected and isolated in biopsy specimens by histopathology and culture-based examination. Analyses of the nuclear 18S rDNA gene and 26S rDNA gene D1/D2 domain sequences and chemotaxonomic studies indicated that this strain represents a novel species with a close phylogenetic relationship to Prototheca wickerhamii and Auxenochlorella protothecoides. This strain grew well at 28–30 °C, showed slow and weak growth at 37 °C, and no growth at 40 °C. This strain grew in vitamin-free medium and assimilated acetate (pH 5.1), L-arabinose and soluble starch as a carbon source. The taxonomic description of Prototheca cutis sp. nov. is proposed (type strain JCM 15793T =CBS 11262T =DSM 22084T) as a pathogen of dermatitis.