Intense Pulsed Light Therapy for Patients with Meibomian Gland Dysfunction and Ocular Demodex Infestation

To observe the clinical changes of meibomian gland dysfunctipn(MGD)and ocular Demodex infestation after intense pulsed light(IPL)treatment to further examine the mechanism of IPL treating patients with MGD and ocular Demodex infestation.The medical records of 25 patients(49 eyes)with MGD treated with IPL,were retrospectively examined to determine outcomes.Associated ocular-surface parameters(ocular surface disease index,OSD1;lipid layer thickness,LLT;noninvasive first breakup time,NIF-BUT;noninvasive average breakup time,NIAvg?BUT;tear film breakup area,TBUA;Schirmer I Test,SIT;corneal fluorescein staining,CFS),eyelid margin abnormalities,meibum quality and expressibility,MG morphological parameters(macrostructure and microstructure),and the number of Demodex infestation were examined before and after treatment.The MG microstructure and the Demodex infestation were examined via in vivo confocal microscopy(IVCM).The results showed that there were statistically significant differences in associated ocular-surface parameters(all P<0.05)before and after IPL treatment,except SIT(P=0.065).Eyelid margin abnormalities,meibum quality and expressibility obviously improved in upper and lower eyelid after IPL treatment(all P<0.0001).MG macrostructure(MG dropouts)decreased in upper(P=0.002)and lower eyelid(P=0.001)after IPL treatment.The nine parameters of MG microstructure in upper and lower eyelid all distinctly improved after IPL treatment(all P<0.0001).The mean number of Demodex mites on the upper lid margin(6.59±7.16 to 3.12±3.81/9 eyelashes)and lower lid margin(2.55±2.11 to 1.29±1.53/9 eyelashes)significantly reduced after IPL treatment(all P<0.0001).The Demodex eradication rate was 20%(8/40)in upper lid margin and 34.15%(14/41)in lower lid margin.These findings indicate that IPL shows great therapeutic potential for patients of MGD and ocular Demodex infestation.

The association between demodex infestation and ocular surface manifestations in meibomian gland dysfunction

AIM： To investigate the association between ocular demodex folliculorum infestation and ocular surface manifestations in meibomian gland dysfunction（MGD）.METHODS： Eight-six patients with MGD were enrolled. All enrolled subjects were tested in the following sequence： ocular surface disease index（OSDI）, slit-lamp biomicroscope examination, corneal surface regularity index（SRI） and surface asymmetry index（SAI）, tear fluid collection, fluorescein tear film break-up time（F-BUT）, corneal fluorescein staining（CFS）, Schirmer I test（SIT） and demodex folliculorum counting. Tear matrix metalloproteinase（MMP）-9 activity was assessed using MMP-9 activity assay kit.RESULTS： Among 86 MGD patients, 40 were positive for demodex. The ocular demodex-positive group showed significantly increased scores of OSDI（25.96±13.74 vs 18.07±11.55, P=0.01）, lid margin abnormality（2.38±0.87 vs 1.98±0.91, P=0.04） and CFS（1.28±2.00 vs 0.94±1.36, P=0.01） compared to the ocular demodex-free group. The tear MMP-9 activity was higher in the ocular demodex-positive group（102.9±32.4 ng/mL） than the ocular demodex-free group（46.2±19.2 ng/mL, P=0.03）. There was no significant difference in meibum quality and expressibility, SRI, SAI, F-BUT and SIT between the two groups（P〉0.05 for each）. No significant correlation was noted between the number of demodex and ocular surface parameters in demodexpositive MGD group（P〉0.05 for each）.CONCLUSION： Ocular demodex folliculorum infestation may be associated with ocular discomfort and ocular surface damage in MGD.

Should ocular Demodex be checked and treated in refractory keratitis patients without blepharitis?

AIM:To evaluate the correlation between Demodex infestation and keratitis,and to assess demodicosis using a simple approach.METHODS:A modified slit lamp illumination(at 40×magnification)was used to observe Demodex tails in 40patients with refractory keratitis and 80 healthy controls.Bacterial smear and culture of the conjunctival sac and corneal lesion were performed to identify the pathogen.Tea tree oil ointment(TTOO)was added as a Demodex killing agent for lid scrubs to the treatment when Demodex infestation was confirmed.RESULTS:Demodex tails were found in all patients compared to 42/80 of the controls(P<0.01).Seventeen patients presented blepharitis,while 23 were free of scales and inflammation at the lid margin.The demodicosis was mild,moderate,and severe in 8,19,and 13 patients,respectively,compared to mild in 42 controls(P<0.01).The keratitis was mild,moderate,and severe in 13,19,and 8patients,respectively.The severity of Demodex infestation was not correlated to the severity of keratitis(P=0.126).The growth of Staphylococcus was revealed in nine patients who did not react to antibiotic eye drops prior to the TTOO treatment.Patients’signs and symptoms got resolved after the lid scrub with TTOO.CONCLUSION:Ocular Demodex needs to be checked and treated in refractory keratitis patients with or without blepharitis.A slit-lamp illumination under high magnification favors the judgment of the severity of Demodex infestation.

Clinical effect of Chinese medicine aerosol fumigation on demodex infection related meibomian gland dysfunction

Objective:To explore the clinical effect of Chinese medicine aerosol fumigation on demodex infection related meibomian gland dysfunction.Methods:In this prospective study,60 patients(120 eyes)were selected and randomly divided into 2 groups:the treatment group(30 cases,60 eyes)was treated with Chinese medicine aerosol fumigation and meibomian gland massage,the control group(30 cases,60 eyes)was treated with meibomian gland massage.Observation of Demodex count,symptom scores,break-up time(BUT),Schirmer I test(SIT),meibomian gland secretion function scores and eyelid fat traits scores were used to compare the difference between before and after treatment.Results:There was no significant difference in Demodex count,symptom scores,BUT,SIT,meibomian gland secretion function scores and eyelid fat traits scores between the 2 groups before treatment(P>0.05).After treatment,symptom scores,meibomian gland secretion function scores and eyelid fat traits and Demodex count of the treatment group were significantly reduced(P<0.01).Conclusion:Chinese medicine aerosol fumigation can relieve symptoms of of demodex infection related meibomian gland dysfunctionand reduce the number of ocular Demodex.

Correlation Demodex Folliculorum and Skin Biophysical Parameters

Purpose: Demodex folliculorum is a transparent mite, 0.3 - 0.4 mm long, which asymptomatically parasitizes the human pilosebaceous follicles. D. folliculorum is observed in normal skin with a prevalence of 100% and a density of ≤ 5 D/cm2 in the adult population. Materials and Methods: This study evaluated the differences in pH on the five facial sites between the two populations with and without D. folliculorum. The relationship between pH and skin surface oil was analyzed in populations with and without Demodex mites. Mongolian 750 subjects (370 males and 380 females) aged 16 - 84 years, who lived in Ulaanbaatar city, were enrolled in this study. The eligibility criteria included a minimum age of 16 and no physical and dermatologic illness, no cosmetic. Results: Skin surface oil among the five facial areas differed significantly in both subjects with and without Demodex folliculorum (P < 0.001). When the skin surface oil on the T-zone, U-zone was compared, those on the T-zone were significantly higher than those of the U-zone (P < 0.001) in both populations (P< 0.01). The pH levels on the five facial sites, and U-zone, T-zone and MFpH differed significantly in among both subjects with and without Demodex folliculorum (P < 0.001). In both groups, the pH levels of the U-zone were significantly lower than the pH of the T-zone (P Conclusions: Among the five facial sites in subjects with Demodex folliculorum, there were significant negative correlations between skin surface oil and pH on the forehead (p < 0.001, r = 652), cheek (P < 0.001, r = 0.656), nose (P < 0.001, r = 0.754), chin (P < 0.001, r = 0.679), and T-zone (P < 0.001, r = 0.698), MFSE-MFpH (P < 0.001, r = 0.483). In contrast, among the five sites in subjects without Demodex folliculorum, a significant negative correlation between skin surface oil and pH was observed on the forehead (p < 0.001, r = 766), cheek (P < 0.001, r = 0.798), nose (P < 0.001, r = 0.706), chin (P < 0.001, r = 0.823), and T-zone (P < 0.001, r = 0.602), U-zone (P < 0.001, r = -0.550)

Facial dermatosis associated with Demodex:a case-control study

Demodex has been considered to be related with multiple skin disorders,but controversy persists.In this case-control study,a survey was conducted with 860 dermatosis patients aged 12 to 84 years in Xi'an,China to identify the association between facial dermatosis and Demodex.Amongst the patients,539 suffered from facial dermatosis and 321 suffered from non-facial dermatosis.Demodex mites were sampled and examined using the skin pressurization method.Multivariate regression analysis was applied to analyze the association between facial dermatosis and Demodex infestation,and to identify the risk factors of Demodex infestation.The results showed that total detection rate of Demodex was 43.0%.Patients aged above 30 years had higher odds of Demodex infestation than those under 30 years.Compared to patients with neutral skin,patients with mixed,oily,or dry skin were more likely to be infested with Demodex(odds ratios(ORs) were 2.5,2.4,and 1.6,respectively).Moreover,Demodex infestation was found to be statistically associated with rosacea(OR=8.1),steroid-induced dermatitis(OR=2.7),seborrheic dermatitis(OR=2.2),and primary irritation dermatitis(OR=2.1).In particular,ORs calculated from the severe infestation(≥5 mites/cm2) rate were significantly higher than those of the total rate.Therefore,we concluded that Demodex is associated with rosacea,steroid-induced dermatitis,seborrheic dermatitis,and primary irritation dermatitis.The rate of severe infestation is found to be more correlated with various dermatosis than the total infestation rate.The risk factors of Demodex infestation,age,and skin types were identified.Our study also suggested that good hygiene practice might reduce the chances of demodicosis and Demodex infestation.

Sociodemographic characteristics and risk factor analysis of Demodex infestation(Acari:Demodicidae)

To identify sociodemographic characteristics and risk factor of Demodex infestation,756 students aged 13-22 years in Xi'an,China were sampled for the school-based cross-sectional study.Demodex was examined using the cellophane tape method(CTP).The results showed that the total detection rate of Demodex was 67.6%.Logistic regression analysis revealed that five variables(gender,residence,sharing sanitary ware,frequency of face-wash per day,and use of facial cleanser) were found to be uncorrelated with Demodex infestation,whereas three variables(age,skin type,and skin disease) were found to be independent correlates.Students aged over 18 years had 22.1 times higher odds of Demodex infestation compared to those under 16 years and students aged 16-18 years also had 2.1 times higher odds compared to those aged 13-15 years.Odds of having a Demodex infestation for oily or mixed skin were 2.1 times those for dry or neutral skin.Students with a facial skin disease had 3.0 times higher odds of being infested with Demodex compared to those without.The inception rate of students with facial dermatoses increased in parallel with increasing mite count.The inception rates were 21.3%,40.7%,59.2%,and 67.7% in the negative,mild,moderate,and severe infestation groups,respectively(χ2=60.6,P<0.001).Specifically,the amount of infested mites and inception rate of acne vulgaris were positively correlated(R2=0.57,moderate infestation odds ratio(OR)=7.1,severe infestation OR=10.3).It was concluded that Demodex prevalence increases with age,and Demodex presents in nearly all adult human.Sebaceous hyperplasia with oily or mixed skin seems to favour Demodex proliferation.Demodex infestation could be associated with acne vulgaris.The CTP is a good sampling method for studies of Demodex prevalence.

A meta-analysis of association between acne vulgaris and Demodex infestation

Until now, etiology of acne vulgaris is still uncertain. Although clinicians usually deny the association between Demodex infestation and acne vulgaris, it has been proved in some clinical practices. To confirm the association between Demodex infestation and acne vulgaris, a meta-analysis was conducted. Predefined selection criteria were applied to search all published papers that analyzed the association between Demodex infestation and acne vulgaris (January 1950 to August 2011) in ISI Web of Knowledge, MEDLINE, and China National Knowledge Infrastructure (CNKI) databases. A meta-analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) based on fixed effects models or random effects models. We enrolled the 60 Chinese and 3 English papers in this meta-analysis, which covered Turkey and 25 different provinces/municipalities in China and 42 130 participants in-cluding students and residents, aged from 1 to 78 years. The pooled OR in random effects models is 2.80 (95% CI, 2.34-3.36). Stability is robust according to sensitivity analysis. The fail-safe number is 18 477, suggesting that at least 18 477 articles with negative conclusions would be needed to reverse the conclusion that acne vulgaris was related to Demodex infestation. So the effect of publication bias was insignificant and could be ignored. It was concluded that acne vulgaris is associated with Demodex infestation. This indicates that when regular treatments for acne vulgaris are ineffective, examination of Demodex mites and necessary acaricidal therapies should be considered.

Cloning and sequence analysis of chitin synthase gene fragments of Demodex mites

To our knowledge,few reports on Demodex studied at the molecular level are available at present.In this study our group,for the first time,cloned,sequenced and analyzed the chitin synthase(CHS) gene fragments of Demodex folliculorum,Demodex brevis,and Demodex canis(three isolates from each species) from Xi'an China,by designing specific primers based on the only partial sequence of the CHS gene of D.canis from Japan,retrieved from GenBank.Results show that amplification was successful only in three D.canis isolates and one D.brevis isolate out of the nine Demodex isolates.The obtained fragments were sequenced to be 339 bp for D.canis and 338 bp for D.brevis.The CHS gene sequence similarities between the three Xi'an D.canis isolates and one Japanese D.canis isolate ranged from 99.7% to 100.0%,and those between four D.canis isolates and one D.brevis isolate were 99.1%-99.4%.Phylogenetic trees based on maximum parsimony(MP) and maximum likelihood(ML) methods shared the same clusters,according with the traditional classification.Two open reading frames(ORFs) were identified in each CHS gene sequenced,and their corresponding amino acid sequences were located at the catalytic domain.The relatively conserved sequences could be deduced to be a CHS class A gene,which is associated with chitin synthesis in the integument of Demodex mites.

Discrimination between Demodex folliculorum(Acari:Demodicidae) isolates from China and Spain based on mitochondrial cox1 sequences

For a long time,classification of Demodex mites has been based mainly on their hosts and phenotypic characteristics.A new subspecies of Demodex folliculorum has been proposed,but not confirmed.Here,cox1 partial sequences of nine isolates of three Demodex species from two geographical sources(China and Spain) were studied to conduct molecular identification of D.folliculorum.Sequencing showed that the mitochondrial cox1 fragments of five D.folliculorum isolates from the facial skin of Chinese individuals were 429 bp long and that their sequence identity was 97.4%.The average sequence divergence was 1.24% among the five Chinese isolates,0.94% between the two geographical isolate groups(China(5) and Spain(1)),and 2.15% between the two facial tissue sources(facial skin(6) and eyelids(1)).The genetic distance and rate of third-position nucleotide transition/transversion were 0.0125,2.7(3/1) among the five Chinese isolates,0.0094,3.1(3/1) between the two geographical isolate groups,and 0.0217,4.4(3/1) between the two facial tissue sources.Phylogenetic trees showed that D.folliculorum from the two geographical isolate groups did not form sister clades,while those from different facial tissue sources did.According to the molecular characteristics,it appears that subspecies differentiation might not have occurred and that D.folliculorum isolates from the two geographical sources are of the same population.However,population differentiation might be occurring between isolates from facial skin and eyelids.

Rare facial dermatological lesions associated with Demodex infection,besides acne vulgaris

I have read with great interest the recent article ＂A meta-analysis of association between acne vulgaris and Demodex infestation＂ by Zhao et al. （2012）, published in Journal of Zhejiang University SCIENCE B （Biomedicine ＆ Biotechnology） （another two articles by Zhao et al. （2011a; 2011b） are also related to Demodex infestation）. The article is highly thought provoking. Interestingly, Demodex infestation may be associated with a number of other facial dermatological lesions besides ache vulgaris.

Factors affecting meibomian gland area loss in symptomatic adults

AIM:To characterize the distribution of meibomian gland(MG)area loss(MGL)and its relationship with demographic characteristics,mites,and symptoms.METHODS:This retrospective observational study included patients who visited the Dry Eye Clinic of Shenzhen Eye Hospital between June 2020 and August 2021.General patient characteristics,ocular symptoms,Demodex test results of the eyelid edges,and the results of a comprehensive ocular surface analysis were collected.MGL was analyzed using Image J software.RESULTS:This study enrolled 1204 outpatients aged 20-80(40.70±13.44)y,including 357 males(29.65%)and 847 females(70.35%).The patients were classified into mild(n=155;12.87%),moderate(n=795;66.03%),severe(n=206;17.11%),and extremely severe(n=48;3.99%)MGL groups.MGL was significantly larger in female than in male(P=0.006).The degree of MGL also significantly differed in age(P<0.001)and the more numbers of mites with severity(P<0.001).Multivariate disordered multinomial logistic regression analysis identified that female sex,older age,secretory symptoms,and a large number of mites were risk factors for MGL(P<0.05).CONCLUSION:Patients with MGL are more likely to be older,female,more numbers of mites,and increased secretion.

热蒸汽处理面部对蠕形螨检出率的影响

目的了解热蒸汽处理面部对蠕形螨检出率的影响。方法选取2023年5—7月在兰州市某三甲医院皮肤科门诊就诊的215例疑似蠕形螨病的患者作为研究对象,同一患者分别在室温和热蒸汽处理面部10 min后在鼻翼两侧行蠕形螨直接刮拭法镜检。结果经热蒸汽处理后面部蠕形螨的检出率明显增高,达63.7%(137/215);而室温状态下人体蠕形螨的检出率仅为28.4%(61/215)。比较患者面部热蒸汽处理前后蠕形螨的检出率,两者差别具有显著性(χ2=54.07,P=0.00)。结论热蒸汽处理面部能显著提升蠕形螨检出率,为临床上人体蠕形螨病的实验诊断方法提供新的参考。

蠕形螨相关干眼症护理的最佳证据总结

目的筛选国内外蠕形螨相关干眼症护理的相关证据,并对最佳证据进行总结。方法系统检索UpToDate、BMJ Best Practice、美国指南网、亚洲干眼协会、国际泪表与眼表协会、中国知网和万方数据等数据库,查找和研究相关的原始研究、指南、专家共识和系统评价。检索期限为建库至2024年3月31日。由2名研究员对文献质量进行评价,并结合专业判断,选取符合标准的文献。结果最终共纳入9篇文献,其中指南2篇、专家共识3篇、系统评价2篇、原始研究2篇。最佳证据包括居家护理、健康教育、干预措施3个类别,共总结出27条证据。结论证据应用人员需结合临床环境及医院特点,针对性地选取应用蠕形螨相关干眼症护理的最佳证据,以提升护理质量,促进患者健康。

蠕形螨睑缘炎的临床特征及疗效分析

目的:探讨不同年龄组蠕形螨睑缘炎患者的临床特征及茶树油湿巾联合深度睑板腺按摩的疗效。方法:回顾性收集2023-01/10就诊于空军军医大学西京医院眼科的蠕形螨睑缘炎患者146例292眼的病例资料,根据不同年龄将患者分为年龄≤45岁的A组(64例128眼)和年龄>45岁的B组(82例164眼)。分析两组治疗前,治疗后1、3 mo的双眼螨虫总计数、泪液分泌量、症状和体征评分及茶树油湿巾联合深度睑板腺按摩的疗效。结果:治疗前A组螨虫计数7(6,8)只,少于B组8(7,9.25)只(P<0.05)。A组眼干评分6(6,7)分,低于B组11(10,12)分(P<0.001)。A组眼表刺激症状评分10(9,11)分,高于B组6(6,7)分(P<0.001)。治疗1 mo后,两组患者螨虫计数下降,症状与体征评分均降低,坚持治疗3 mo各临床指标仍有不同程度改善,其中B组患者在治疗持续至3 mo时,螨虫计数仍有减少[-1(-3,0)只]。结论:年龄大于45岁的年长患者螨虫数量高于45岁以下患者,眼干严重,但眼表刺激症状较轻。茶树油湿巾联合深度睑板腺按摩治疗蠕形螨睑缘炎能有效减少不同年龄患者的螨虫数量,但泪液分泌量治疗后无明显变化,较长的治疗周期可获得持续的临床获益。

活体激光共聚焦显微镜观察蠕形螨感染与麦粒肿关系的临床研究

目的 采用活体激光共聚焦显微镜(IVCM)观察麦粒肿和霰粒肿患者眼部蠕形螨感染情况,为分析蠕形螨感染对麦粒肿发生的影响提供参考依据。方法 选取2022年6—12月在上海爱尔眼科医院就诊为霰粒肿的患者45例(45眼)称霰粒肿组及无霰粒肿史的麦粒肿患者45例(45眼)称麦粒肿组。每位患者采取活体激光共聚焦显微镜观察患眼睑缘蠕形螨感染情况,上下睑缘选取累及所在位置8个毛囊、8个睑板腺。以蠕形螨检出≥3只为阳性、1≤蠕形螨<3只为可疑阳性、未检出为阴性。结果 活体激光共聚焦显微镜下,麦粒肿组和霰粒肿组蠕形螨感染阳性率分别为73.30%(33眼)、44.44%(20眼),可疑阳性率为31.11%(14眼)、11.10%(5眼),阴性率为15.60%(7眼)、24.44%(11眼);麦粒肿组阳性感染率明显高于霰粒肿组,差异具有统计学意义(P=0.013)。结论 与霰粒肿患者相比,麦粒肿患者的蠕形螨感染率更高,蠕形螨感染可能亦是麦粒肿发生的致病因素之一。

Prevalence of ocular demodicosis among patients at Tertiary Care Center,Bangkok,Thailand

AIM： To determine the prevalence of ocular demodicosis by both microscopic examination and molecular detection among patients at King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok.METHODS： One hundred individuals were enrolled in the study and were divided into five age groups. The meibomian gland dysfunction （MGD） score and qualities of cylindrical dandruff （CD） were also determined. Demodex mite infestations of eyelash samples were screened by both microscopic examination and semi-nested polymerase chain reaction （PCR）. RESULTS： The prevalence of ocular demodicosis as determined by microscopic examination was 42% [Demodex folliculorum （D. folliculorum） 41% and Demodex brevis （D. brevis） 1%]. Among patients who had ocular Demodex infestation, 69% have CD and had an average MGD score of 4; in patients without demodicosis, 15.5% had CD and had an average MGD score of 4.12. Prevalence of ocular demodicosis as determined by semi-nested PCR was 79% （D. folliculorum 78% and D. brevis 1%）.CONCLUSION： This is the first report on the prevalence of ocular demodicosis in Thailand. Patients with CD also had Demodex mites present. Semi-nested PCR is better than microscopy for Demodex infestation detection. An extensive survey with more representative samples is required to determine the prevalence in the country.

唐山市大学生面部蠕形螨感染情况调查

2008年对唐山市4所高校512名大学生进行了蠕形螨感染情况调查。结果显示,大学生面部蠕形螨的总感染率为36.3%(186/512),其中男、女性感染率分别为39.3%(81/206)和34.3%(105/306)(P>0.05)。在蠕形螨感染者中,毛囊型、皮脂型和混合型分别占82.3%(153/186)、7.5%(14/186)和10.2%(19/186);额部、鼻尖部和鼻翼侧的感染分别占43.0%(80/186)、50.0%(93/186)和31.7%(59/186)。不同皮肤类型的感染率不同,油性、干燥型和混合型皮肤的感染率分别为47.0%(93/198)、26.6%(37/139)和33.9%(56/165),三者差异有统计学意义(P<0.05)。面部有酒糟鼻和痤疮等疾患者蠕形螨的感染率为62.0%(75/121),高于面部无疾患者(27.6%,80/290),两者差异有统计学意义(P<0.05);居住环境潮湿者感染率为67.9%(95/140),远高于居住环境干燥者(24.5%,91/372),两者差异有统计学意义(P<0.05)。

桉叶油对两种蠕形螨的体外杀虫作用

目的观察桉叶油的体外杀螨效果。方法采用透明胶带粘贴过夜法获取两种人体蠕形螨,随机分为5组,观察不同浓度下的桉叶油对两种人体蠕形螨的杀灭作用,并在Motic DMB5图像采集软件系统下记录加药后虫体的死亡过程。结果桉叶油对两种人体蠕形螨均有明显的体外杀灭作用,对皮脂蠕形螨的杀虫效果优于毛囊蠕形螨。随着药物作用时间的延长及浓度的增加,蠕形螨死亡率增高。6.25%的桉叶油是杀灭人体蠕形螨的最低有效浓度,而12.5%的桉叶油是杀死人体蠕形螨的最适浓度。显微镜下动态观察发现,加药后蠕形螨的形态及活动度变化大多为先剧烈收缩,活动加强,后虫体松弛,活动减弱,直至死亡。结论桉叶油是一种低毒、经济、高效的杀螨药物。

人体蠕形螨的DNA提取与随机引物PCR检测

【目的】探索人体毛囊蠕形螨和皮脂蠕形螨DNA的提取方法。【方法】采用液氮反复冻融研磨法破碎螨体细胞,选用改良小昆虫DNA提取法、碱裂解法和试剂盒提取法,分别提取冻存时间在5个月内和8～10个月的毛囊蠕形螨和皮脂蠕形螨基因组DNA,并用随机引物PCR方法进行检测。【结果】蛋白核酸测定仪检测结果显示,试剂盒法提取的DNA纯度较高、量较多,明显优于改良小昆虫法和碱裂解法。随机引物扩增结果显示清晰的DNA指纹图谱,两种人体蠕形螨DNA指纹具有明显差异。蠕形螨冻存时间影响DNA提取的量,但对DNA提取的纯度和RAPD指纹图谱影响较小。不同DNA提取方法提取的同一种蠕形螨DNA指纹图谱基本相似,试剂盒法和改良小昆虫法提取的DNA样本条带多而清晰,碱裂解法提取的样本条带少而模糊。【结论】液氮反复冻融研磨法破碎蠕形螨细胞是有效的,蠕形螨冻存时间不宜超过6个月,试剂盒提取法是提取蠕形螨DNA的好方法。RAPD技术可以用于这两种人体蠕形螨DNA分子水平上的检测和分类。