儿童头癣环境中致病真菌调查及分子流行病学研究

发布时间：2018-05-27 22:12

本文选题：儿童 + 头癣　；参考：《昆明医学院》2011年硕士论文

【摘要】：目的：调查分析儿童头癣患者环境中致病真菌存在情况,进行分子流行病学研究从而了解致病真菌与生活环境中致病真菌的差异性,探索其流行病学规律,为儿童头癣的防治提供依据。方法：1.以临床确诊头癣的儿童为研究对象,对病发进行真菌镜检和真菌培养,同时收集每例头癣儿童的生活环境中密切接触物品(患者近亲属爷爷或外公、奶奶或外婆、爸爸、妈妈、兄弟姐妹或伙伴头发,枕巾、床单、沙发、地板或地毯灰尘及接触的宠物毛发)进行真菌培养。2.环境中分离真菌培养阳性结果与相应头癣儿童的真菌培养结果进行对比分析；如经鉴定为相同菌株,则采用真菌通用引物ITS1和ITS4对分离出的致病菌rDNA的ITS区进行扩增,并采用(GACA)4单引物对致病菌进行分子鉴定,随后应用随机引物扩增DNA多态性(RAPD)方法对致病菌进行种内株间分型以确定菌株的差异性。结果：1.调查了91例儿童头癣患者,发病年龄从1岁3个月至12岁,平均年龄6.4岁。患者病发的真菌培养结果犬小孢子菌44株(48.35%),铁锈色小孢子菌41株(45.05%),须癣毛癣菌4株(4.40%),红色毛癣菌1株(1.10%),石膏样小孢子菌1株(1.10%)。2.患者近亲属头发及枕巾等接触物品真菌培养结果均未分离到致病真菌；2例儿童的伙伴(邻居小孩,同时有头癣症状),病发中分离到与患儿相同的致病菌,一例为犬小孢子菌,另一例为铁锈色小孢子菌,与其对应儿童头癣患者病发培养结果一致；有宠物接触者28例(30.77%),其中7例分离到与头癣患者病发相同的致病菌种,占总比例的7.69%。3.用ITS1和ITS4引物在8例患者病发与其对应生活环境中提取的共16株犬小孢子菌均扩增出一约760bp左右的特异性条带,从基因水平进一步证实16株菌均为犬小孢子菌。(GACA)4单引物均扩增出三条带,进一步将16株犬小孢子菌鉴定至种的水平。4. RAPD分析发现从8例患者分别与其对应环境中分离的犬小孢子菌的基因组DNA随机引物扩增后产生的产物片断长度多态性一致,显示无株间差异性。结论：1.儿童头癣发病率以3-6岁、7-9岁年龄段儿童为高峰,说明该年龄段儿童为头癣的重点防治对象,3岁以下及10岁以上儿童的发病率较低。2.犬小孢子菌为头癣最常见的致病真菌,其次为铁锈色小孢子菌。3.实验结果表明儿童头癣患者的周围环境中有致病真菌的存在,且主要存在于患者密切接触宠物的毛发和密切接触伙伴的头发中,说明儿童头癣可由宠物直接传染给儿童,也可通过密切接触的伙伴而相互传染,提示儿童头癣的预防中应尽量少接触宠物,若有患头癣的伙伴应减少密切接触。
[Abstract]:Objective: to investigate the presence of pathogenic fungi in the environment of children with tinea capitis, and to investigate the differences between pathogenic fungi and pathogenic fungi in living environment. To provide evidence for prevention and treatment of tinea capitis in children. Method 1: 1. Children with clinically diagnosed tinea capitis were studied by fungal microscopy and fungal culture. At the same time, close contact items were collected in the living environment of each case of tinea capitis (grandfather or grandfather, grandmother or grandmother, father, mother, father, mother). Siblings or associates with hair, pillow towels, sheets, sofas, floor or carpet dust and contact pet hair) for fungal culture. 2. The positive results of fungal culture in environment were compared with those of the corresponding children with tinea capitis. If identified as the same strain, the ITS region of rDNA was amplified by fungal universal primer ITS1 and ITS4. A single primer was used to identify the pathogenic bacteria, and then random primer amplified polymorphic DNA (DNA) was used to type the pathogenic bacteria in different strains in order to determine the difference of the strains. The result is 1: 1. 91 children with tinea capitis were investigated. The onset age ranged from 1 year, 3 months to 12 years, with an average age of 6.4 years. The results showed that 44 strains of microsporozoa canis, 41 strains of Microsporum ferrorust, 4 strains of Trichophyton versicolor, 4 strains of Trichophyton rubrum, 1 strain of Trichophyton rubrum and 1 strain of Microsporum gypsum were cultured. The results of fungal culture in the hair and pillow towel of close relatives of the patients were not found in 2 children (neighbor children, with tinea capitis symptoms). The same pathogenic bacteria were isolated in the hair of the patients and one case was microsporum canis. The other case was Microsporum ferrochroma, which was consistent with the result of culture in children with tinea capitis, 28 cases with pet contact and 30.77%, of which 7 cases were isolated from the same pathogenic species as the patients with tinea capitis, accounting for 7.69% of the total. A specific band of about 760bp was amplified by ITS1 and ITS4 primers from 16 strains of microsporum canis isolated from 8 patients. It was further confirmed from gene level that 16 strains of microsporozoa canis were all microsporozoa canis. The single primer 4 amplified three bands, and further identified 16 strains of microsporozoa canis to the level of species. 4. RAPD analysis showed that the length polymorphism of microsporozoa canis genomic DNA amplified by random primers from 8 patients and their corresponding environments were identical, showing no difference between plants. Conclusion 1. The incidence of tinea capitis was the highest in children aged 3-6 years and 7-9 years old, indicating that the incidence rate of children under 3 years old and over 10 years old was lower than that of children aged 10 years. Microsporum canis is the most common pathogenic fungus of tinea capitis, followed by Microsporum ferrorust. 3. The results show that there are pathogenic fungi in the surrounding environment of children with tinea capitis, and mainly in the hair of the pet and the hair of the partner, indicating that the tinea capitis of children can be transmitted directly from the pet to the child. It can also be transmitted through close contact with each other, suggesting that children with tinea capitis should be as little as possible contact with pets, if there is tinea capitis partners should reduce close contact.
【学位授予单位】：昆明医学院
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R756.1

【参考文献】