先天性心脏病儿童牙菌斑中白色念珠菌的携带情况

目的：研究先天性心脏病儿童牙菌斑中白色念珠菌的携带情况。方法：根据WHO龋齿诊断标准,以115名2～5岁的先心病儿童作为研究对象,其中有龋组86人,无龋组29人,同时选取115例健康儿童为对照组,临床检查记录龋失补牙数（dmft）、龋失补牙面数（dmfs）及可视菌斑指数（VPI）;采集龈上菌斑及龋坏组织,应用SYBR green I荧光定量PCR方法,对各组样本中白色念珠菌含量进行检测,所获得的数据进行统计学分析。结果：先心病组患龋率为74．8％,dmft、dmfs及VPI分别为5．69±5．69、11．83±15．14、43．8％±24．1％;对照组受检儿童患龋率为67．0％,dmft、dmfs、VPI分别为3．53±4．02、5．51±7．40、36．5％±24．1％。两组dmft,dmfs,VPI的差异有统计学意义。儿童牙菌斑中白色念珠菌的含量（Log10 copies/mL）,先心病有龋组龋洞和牙颈部分别为6．71±2．92、5．64±3．11,无龋组为5．03±2．74;正常儿童有龋组龋洞和牙颈部分别为4．01±2．35、3．27±2．14,无龋组为3．43±2．56。先心病儿童与正常儿童牙菌斑中白色念珠菌含量差异具有统计学意义。结论：先心病儿童牙菌斑中白色念珠菌的含量高于正常儿童。口腔中的白色念珠菌,可能成为感染性心内膜炎的菌源之一,使先心病儿童成为感染心内膜炎的易感人群。     

Persistence of oral Candida albicans carriage in healthy Portuguese schoolchildren followed for 3 years

Little is known about carriage of Candida albicans, the predominant pathogenic yeast in oral infection, in children. We cultured buccal mucosal and gingival swabs from 150 Portuguese children to investigate the prevalence of C. albicans at baseline (before dental treatment), post-treatment, and 12, 24, and 36 months post-baseline. The children, aged 8 to 11 years at baseline, had no systemic disease or clinical symptoms of oral candidiasis. At each successive visit, respectively, 47, 32, 21, 27, and 28% of children were C. albicans positive, resulting in an almost 50% reduction in prevalence from baseline to post-treatment (P < 0.0005). Children who carried C. albicans at one visit had 3 to 20 times greater odds of carrying C. albicans at another visit. C. albicans was cultured from 12 children at all time-points and from 10 children at four time-points. Children with oral C. albicans frequently maintained carriage over time, even with regular dental care.     

各年龄段儿童口腔中念珠菌的分布研究

目的 研究以白色念珠菌为代表的念珠菌群在不同年龄阶段儿童口腔中的分布情况。方法 对4个不同年龄阶段的儿童口腔中的念珠菌群进行研究，颊黏膜拭子取样，鉴定培养基培养鉴定，比较培养法和PCR法对其中一组样本的白色念珠菌检出率的影响。结果念珠菌的检出率分别是：新生儿7．5％，乳牙列儿童组70％，混合牙列儿童组56．36％，恒牙列儿童组49．12％；白色念珠菌的比例各有不同，PCR方法比培养法更加敏感。结论 各个年龄阶段儿童口腔中均有念珠菌的检出，但检出率不同，白色念珠菌是主要成分。     

维吾尔族高龋儿童口腔中白色念珠菌基因分型研究

目的：研究乌鲁木齐市维吾尔族儿童口腔白色念珠菌的分布及高龋儿童口腔白色念珠菌基因分型。方法：利用科玛嘉念珠菌显色培养基对144名维吾尔族3～5岁儿童进行口腔白色念珠菌分离培养及鉴定,进行 PCR25SrDNA 基因分型。结果：35个儿童（24．3％）的口腔中检出白色念球菌。无龋、有龋、高龋儿童口腔白色念珠菌检出率分别为3．8％、50．0％和35．7％（χ2＝22．246,P ＝0．000）;25例高龋儿童的 PCR25rDNA 分3型,以 A 型为主（72．0％）。结论：白色念珠菌可能是维吾尔族儿童龋病的危险因素,白色念珠菌 PCR25SrDNA 基因的 A 型者可能更易致龋。     

Prevalence of Candida albicans in oral cavities and root canals of children

The aim of this study was to examine the prevalence of C. albicans in the oral cavities and root canals of children. Twenty healthy and caries-free children and 13 children with caries, were screened. Imprint samples and sterile paper points were used to obtain the samples from oral cavities and root canals respectively. The production of germ tubes and the development of chlamydospores identified yeast cultures. Sixty-nine percent of children with caries and 5% of caries-free children were found to be Candida carriers. The difference in candidal prevalence between two groups was significant (p < 0.05). Sixty-one point five percent of children were positive for Candida in the root canal. Since, increase in the C. albicans in the oral cavity provides a potential source of the fungus particularly when resistance falls below a certain threshold, attention to strategies for the reduction of this pervasive and persistent pathogen becomes important. Therefore, reduction of caries and or introduction of antifungal agents during root canal treatment of children may be offered.     

Prevalence of yeast among children in Nigeria and the United States

Fungal infections have gained considerable importance over the last decade as a result of significant increase in the incidence of opportunistic and systemic candidosis. Although Candida albicans is the predominant causative agent of candidosis, particularly oral disease, recently an epidemiological trend has been observed where other less pathogenic species of Candida, including the newly characterized species Candida dubliniensis, are emerging as significant opportunistic pathogens. The present study aimed to screen for the presence of C. dubliniensis and to compare the recovery of yeast species from 30 seemingly healthy and 30 HIV-positive children in the United States, as well as from 64 malnourished Nigerian children. Oral samples were cultured for fungal growth, and all germ tube and chlamydospore positive isolates were tested for ability to grow at 45 degrees C to differentiate between C. albicans and C. dubliniensis. All isolates were speciated based on colony color production on CHROMagar medium and sugar assimilation profiles. Among the 30 HIV-positive children, 15 (50%) were positive for fungus; 12 were positive for C. albicans, with one of the latter also positive for Candida glabrata, and three were found to harbor C. dubliniensis. Among the 30 non-HIV-positive children, five C. albicans and four C. dubliniensis isolates were recovered. No C. dubliniensis isolates were recovered from the Nigerian group. However, eight other different yeast species were recovered from 31 (48.4%) of the 64 Nigerian children sampled, with six of them growing a combination of species. In comparing the data from the Nigerian and United States children, the frequency of yeasts in the malnourished Nigerian group was considerably higher. The most striking difference between the two groups was in the variety of the usually less encountered and less pathogenic yeast species recovered from the Nigerian population. The findings support previously reported observations that there may be intrinsic differences between different populations sampled and that malnutrition might favor the presence of yeast species other than C. albicans.     

喀什市3~5岁维吾尔族儿童婴幼儿龋相关因素的主成分分析

目的:应用主成分Logistic回归分析法研究喀什市3~5岁维吾尔族儿童口腔龋病与白色念珠菌检出情况及危险因素的相关性。方法:采用分层整群抽样的方式随机抽取喀什市397名3～5岁维吾尔族健康儿童作为研究对象,对其进行口腔检查及采集牙菌斑,通过分离纯化培养及聚合酶链反应检测白色念珠菌检出情况。同时采用问卷调查家长对儿童的喂养方式、饮食习惯等。对白色念珠菌的检出情况,是否长期使用奶瓶、是否经常吃零食等20个婴幼儿龋病相关危险因素,采用方差极大正交旋转法进行主成分Logistic回归分析。结果:主成分分析结果显示特征值大于1的因子数目有7 个,分别为:细菌因素、喂养/饮食习惯和家族史因子、宿主因素作用因子、口腔卫生习惯作用因子、社会经济背景作用因子、牙周状况作用因子、使用牙线、和性别因子,对总方差的累积贡献率为70.027%。经Logistic回归分析得出牙周状况和性别无统计学意义,其他因子均与婴幼儿龋病密切相关。结论:喀什市儿童龋病的发生是由多种因素共同作用的结果,除宿主自身因素、饮食习惯等因素外,白色念珠菌的检出也与龋病密切相关。运用主成分分析法构建的综合评价模型可以消除原始变量间的信息重叠,精简数据,客观、合理、综合地评价婴幼儿龋病危险因素的相关性,为当地儿童龋病的防治提供理论依据。     

Distribution and hydrolytic enzyme characteristics of Candida albicans strains isolated from diabetic patients and their non-diabetic consorts

Introduction:  The aim of this study was to investigate the oral colonization profile of Candida albicans strains isolated from diabetic patients and their non-diabetic consorts. In addition hydrolytic enzyme activity of these isolates was analysed.
Methods:  The genetic diversity of C. albicans oral isolates from 52 couples was established using isoenzyme marker and cluster analysis. Hydrolytic enzyme characteristics, namely secreted aspartyl proteinases (SAPs) and phospholipases (PLs) were also analysed.
Results:  Simultaneous colonization by C. albicans was observed in the consorts of 12 couples (23.1%). Patterns of monoclonal and polyclonal oral colonization by C. albicans strains were identified and the coexistence of identical or highly related strains was observed in both members of eight couples. The genetic diversity observed in the total yeast population revealed four large, genetically distinct groups (A to D) and the coexistence of strains in couples or consorts conjugally unrelated. SAP and PL activity was observed in the majority of C. albicans isolates without any association to particular strain, strain clusters (highly related isolates), or clinical characteristics of the consorts (diabetic, non-diabetic, and gender).
Conclusion:  Possible sources of transmission and oral propagation of groups (clusters) of strains of C. albicans can occur between diabetic and non-diabetic consorts. A conjugal genotypic identity exists in most C. albicans -positive couples, that is, both consorts share identical or highly related strains; however, this identity is not couple-specific as seen by the coexistence of clusters in couples and unrelated consorts.     

口腔念珠菌带菌与感染状态分离菌株的RAPD分析

目的 :研究念珠菌种之间及不同来源白念珠菌菌株之间的基因型相关性。方法 :对口腔白念珠菌病原菌、共生菌及非白念病原菌分别进行表型和RAPD分析。结果 :白念珠菌与非白念珠菌的RAPD带型存在差异 ,相似系数在 5 1.7%。共生菌与病原菌RAPD带型未见差异。白念珠菌种内相似系数大于 70 % ,菌株间存在DNA多态性。结论 :共生白念珠菌与病原菌未见RAPD带型差别 ,提示对口腔念珠菌病的防治应重视宿主因素在发病中的作用。     

Frequency and density of yeasts in the mouths of malnourished children

The prevalence and density of yeasts and Candida albicans on the buccal mucosa and dorsum of the tongue have been assessed in 106 children in Crossroads squatter camp, South Africa. They were divided into a malnourished and a control group on the basis of an age/weight chart. No differences were found in yeast prevalence and density in the two groups. However, malnourished children more frequently had a mucosal density of yeasts, and particularly C. albicans, exceeding the upper limit normally found in health, in the absence of clinical infection. Some evidence was found to suggest that yeast density might be influenced by sex as well as nutritional status.     

Clonal identity of Candida albicans in the oral cavity and the gastrointestinal tract of pre-school children

The clonal relationship between oral and fecal Candida albicans isolated from children of pre-school age was examined using RAPD analysis. Significantly higher levels of C. albicans were found in saliva, dental plaque, carious specimens and stools of 56 patients with severe caries as compared to 52 healthy control subjects. The highest prevalence was found in carious specimens and a strong correlation was observed between its presence in saliva, dental plaque, carious specimen and feces. RAPD analysis of isolates from 23 patients with simultaneous oral and fecal C. albicans revealed clonal counterparts present in both oral and stool samples in 15 cases; five patients harbored closely related strains; and three patients harbored unrelated strains. Our results demonstrate a strong correlation between oral and gastrointestinal C. albicans colonization. We assume that carious teeth may constitute an ecologic niche for C. albicans potentially responsible for recurrent oral and non-oral candidiasis.     

Ectophosphatase activity in Candida albicans influences fungal adhesion: study between HIV‐positive and HIV‐negative isolates

Oral Diseases (2010) 16 , 431–438 Objective: This study describes the expression of acidic ectophosphatase activity on twenty isolates of C. albicans from oral cavities of HIV‐infected children (HIV+) and compares them with fifteen isolates from HIV‐negative children (HIV?), as well as the fungal adhesion to epithelial cells and medical records. Methods: The activities were measured in intact cells grown in BHI medium for 48 h at 37°C. Phosphatase activity was assayed at pH 5.5 using 4‐methylumbelliferyl phosphate. Yeast adhesion was measured using the MA 104 epithelial cell line. Results: Mean values of ectophosphatase activity were 610.27 ± 166.36 and 241.25 ± 78.96 picomoles 4‐methylumbelliferone/h/10⁷ cells for HIV+ and HIV? group, respectively (P = 0.049). No correlation between C. albicans enzyme activity from HIV children with viral load and CD4 percentual was observed. Yeasts with high enzyme activity, isolated from HIV+ children showed greater adherence than yeasts with basal levels of ectophosphatases from HIV? (Spearman correlation, r = 0.8). Surface phosphatase activity was apparently involved in the adhesion to host cells, as the enhanced attachment of C. albicans to host epithelial cells was reversed by pretreatment of yeast with sodium orthovanadate (1 mM), an acid phosphatase inhibitor. Conclusion: These results show that C. albicans from HIV+ has an ectophosphatase activity significantly higher than the other isolates. Yeasts expressing higher levels of surface phosphatase activity showed greater adhesion to epithelial cells. So, the activity of acidic surface phosphatases on these cells may contribute to the early mechanisms required for disease establishment.     

Analysis of the strain relatedness of oral Candida albicans in patients with diabetes mellitus using polymerase chain reaction-fingerprinting

To increase our understanding of Candida pathogenicity, the identification of those strains most frequently associated with infections is of paramount importance. Polymerase chain reaction (PCR)-based methods are extremely effective in differentiating and determining reproducibility, they require minimum starting material and are rapid and simple to perform. In this study, the genetic relatedness of Candida albicans was assessed for two geographically different patient groups (London, UK and Parma, Italy) affected by diabetes mellitus. C. albicans samples from the oral cavities of non-diabetic healthy subjects were also examined by PCR fingerprinting to evaluate the possible genetic differences among endogenous strains in individuals with and without diabetes mellitus. PCR fingerprinting, with subsequent phylogenetic analysis of C. albicans isolates from the diabetic patients from London and Italy and from the non-diabetic subjects, revealed that there were significant differences (P < 0.0001) between C. albicans isolates indicative of the distinct ecological niches that occur in the oral cavities of these patient cohorts. The most diverse group comprised the isolates from the diabetic patients in the UK, possibly reflecting the antifungal treatment that these patients had received. Further studies that include isolates from patient cohorts with systemic diseases other than diabetes mellitus, and from more diverse geographic localities are required to explain the relatedness of C. albicans isolates in the mouth.     

Oral lesions in children born to HIV–1 positive women

A cohort of 69 children born to HIV-1 positive women was studied to evaluate types, prevalences and relationships to clinical stages of HIV-1-related oral lesions. In addition, relationships among C. albicans biotypes, clinical features of oral candidiasis and HIV-1 disease were investigated. C. albicans biotypes did not correlate with clinical features of oral lesions, disease stages and CD4⁺ lymphocyte count. Of 8 patients with recurrent oral candidiasis. 4 changed clinical features and 5 changed biotype. Our study pointed out the high frequency (28.9%) of oral lesions, especially caused by fungi and the importance of the examination of the oral cavity in children born to HIV-1 positive women.     

Association of maternal-child characteristics as a factor in early childhood caries and salivary bacterial counts

The aim of this study was to investigate the caries-related microorganisms in saliva and the prevalence of Early childhood caries (ECC) in 15- to 35-month-old Turkish children and their associations with the characteristics of the mothers, socioeconomic criteria, and feeding habits of the children. METHODS: Saliva samples of 101 children were studied to determine the numbers of Streptococcus mutans, lactobacilli, and Candida albicans. A questionnaire regarding the characteristics of the mothers, socioeconomic criteria, and feeding habits of the children was carried out before the dental examinations of the mother-child pairs. RESULTS: The regression analyses revealed DMFS scores of the mothers as an impact factor for the children's caries experience. The prolonged usage of feeding bottle with sweetened milk, pacifier use, and maternal sharing were strongly associated with the colonization of S. mutans, lactobacilli, and C. albicans, respectively. A significant correlation was also found between maternal education and S. mutans. CONCLUSION: Data indicated that the mother's DMFS scores, education, and feeding habits were strong risk indicators for the colonization of caries-related micro-organisms and ECC.     

Presence of mutans streptococci and Candida spp. in dental plaque/dentine of carious teeth and early childhood caries

This study determined the presence of mutans streptococci and Candida spp. in supragingival dental plaque and infected dentine of caries-free children, with early childhood caries and caries. Pooled samples of dental plaque and infected dentine were collected from 56 children aged 1-5 years, which were divided into 3 groups: early childhood caries (ECC); caries and caries-free. Infected dentine was collected in ECC and caries groups to compare the frequency of these microorganisms in the collected sites. The samples were inoculated in SB20 and SA medium, for mutans streptococci and Candida spp., respectively, and incubated at 37 degrees C for 48 h. Colony growth was verified and the identification was performed by biochemical tests and CHROMagar Candida. Fisher's test or chi-square (chi(2)) were applied (p=0.05). The more prevalent species were S. mutans and Candida albicans in ECC (85.4% and 60.4%, respectively), independently of the sample site. S. mutans only was significantly associated with carious teeth, whether in early childhood caries or not. However, the frequency of C. albicans in ECC was higher when compared to caries and caries-free groups. There is a significant association between the presence of C. albicans and early childhood caries.     

口腔白色念珠菌基因型与扁平苔藓的关系

目的:分析口腔白色念珠菌基因型与口腔扁平苔藓的关系,白色念珠菌致病菌与共生菌基因型的相关性,为临床制定有效防治措施提供依据。方法:采用随机扩增多态性DNA(RAPD)基因分型方法,对46株口腔念珠菌行基因型观察。46株菌分为以下3组,自健康志愿者口腔中所取的9株共生菌为N组;自口腔单纯白色念珠菌感染者口腔中所取的21株致病菌为OC组;口腔扁平苔藓伴发的16株致病菌为LP组。结果:46株念珠菌中,40株被鉴定为白色念珠菌,基因分型显示不同念珠菌有各自独特基因型。OC组与N组白色念珠菌基因型相似度较高。LP组白色念珠菌基因型无集中趋势,与N组比较存在显著差异(P<0.001)。同是致病菌的白色念珠菌,组与组间基因型也存在显著性差别(P<0.001)。结论:(1)RAPD基因分型可将念珠菌区分至菌种水平,也可深入分辨“同种异型”。(2)口腔单纯白色念珠菌感染可能由共生菌菌群失调引起,即由内源性感染引起。(3)扁平苔藓伴发白色念珠菌基因型无集中趋势,提示扁平苔藓伴发白色念珠菌存在外源性感染的可能。(4)不同口腔黏膜病所伴发的白色念珠菌基因型不同。     

小鼠对口腔念珠菌感染的体液免疫应答

目的建立敏感株和阻抗株小鼠口腔念珠菌感染模型，揭示两种小鼠对口腔念珠菌感染的体液免疫反应。方法雌性BALB／c和CBA／CaH小鼠及白色念珠菌3630用于本研究。1×10^8念珠菌／20μl接种于小鼠的口腔黏膜，建立口腔念珠菌感染模型；SDS—PAGE和Western—Blotting用于检测血清抗体。结果念珠菌敏感株鼠CBA／CaH的口腔感染比阻抗株鼠BALB／c严重（P〈0．05）；CBA／CaH小鼠在口腔免疫后5周产生了IgG1、IgG2a、IgM，而BALB／c小鼠仅产生IgG1。结论念珠菌敏感鼠CBA／CaH的口腔念珠菌感染比念珠菌阻抗鼠BALB／c感染更为严重；抗白色念珠菌抗体IgM可能对宿主的口腔念珠菌感染起保护作用。     

Sj?gren's syndrome sufferers have increased oral yeast levels despite regular dental care.

AIM: To investigate the prevalence and quantity of oral yeasts and their association with oral candidiasis in Sj?gren's syndrome (SS) patients receiving regular dental care. MATERIALS AND METHODS: Yeasts in oral rinse and full-mouth supra-gingival plaque samples from 25 primary SS, 27 secondary SS and 29 control subjects were selectively cultured. All yeasts except single-species isolates were genotyped using pulsed field gel electrophoresis (PFGE). RESULTS: Ten (19%) SS sufferers had symptomless candidiasis. SS subjects had a higher prevalence (73%vs 7%) and quantity of yeasts than controls in both oral rinse and plaque samples (P < 0.05). The prevalence of yeasts in plaque was associated with candidiasis regardless of denture wearing (P < or = 0.04). Candida albicans was the predominant yeast isolated. PFGE showed 20 (66% of total) C. albicans isolate pairs, i.e. C. albicans species isolated from plaque and oral rinse samples of the same individual, were of closely related genetic clonal types (P < 0.01). CONCLUSIONS: Despite effective oral hygiene, more SS subjects than controls had detectable levels of oral yeasts and their presence in supra-gingival plaque was associated with candidiasis. Candida albicans colonized supra-gingival biofilm even in well-maintained SS individuals, posing a challenge to the control of oral candidiasis.     

Infections in hospitalised Russian children with AIDS

OBJECTIVES: (1) To determine the most common infections in hospitalised children with AIDS. (2) To identify the pathogens causing the above infections. (3) To investigate the possibility of nosocomial transmission of potential pathogens in a Russian AIDS hospital. SETTING: Russian AIDS Hospital for Children. SUBJECTS AND METHODS: Swabs/samples of skin, mouth, nose, urine and stool were collected from 95 hospitalised children with AIDS, 12 of their mothers and 11 health care workers in contact with the children. Hospital objects were also sampled. The predominant isolates from the infection sites were speciated. Antibiotic sensitivity profiles, phagotyping and gel electrophoresis of cell lysates were used for the epidemiological marking of Candida albicans, Staphylococcus aureus and Klebsiella pneumoniae. RESULTS: Oral infections were the most prevalent infections in this study group. The most frequently isolated micro-organisms were C. albicans, S. aureus, K. pneumoniae and Escherichia coli. The results of the epidemiological study suggests nosocomial transmission of these strains. CONCLUSIONS: The present chemoprophylaxis programme for opportunistic oral infections requires revision. Systems of microbiological surveillance and cross-infection control monitoring in relation to immunocompromised patients need to be developed to decrease the possibility of nosocomial transmission of potential pathogens between hospitalised children with AIDS, their mothers and health care providers.