In vitro adherence of Candida albicans isolated from patients with chronic periodontitis

Adherence is considered an extremely important virulence factor in yeast. OBJECTIVE: The aim of this study was to analyze the adherence to epithelial cells of C. albicans isolated from patients with chronic periodontitis in comparison to healthy patients. MATERIAL AND METHODS: Candida albicans cells isolated from individuals with chronic periodontitis (n=25) and healthy controls (n=25) were included in this study. Suspensions of C. albicans (10(6) cells/mL) and epithelial cells (10(5) cells/mL) were mixed and incubated at 37ºC for 1 h. The number of yeasts adhered to 25 epithelial cells was counted. RESULTS: The number of C. albicans cells adhered to epithelial cells was statistically higher in the chronic periodontitis group than in the control group (Student's t-test, p=0.000). CONCLUSION:The results of the present study suggest a higher Candida adherence of samples isolated from patients with chronic periodontitis

Prevalência e suscetibilidade aos antibióticos de enterococcus spp. isoladas da cavidade bucal humana

O objetivo deste estudo foi avaliar a prevalência e suscetibilidade aos antibióticos de Enterococcus spp. isolados da cavidade bucal de indivíduos (n=240) de diferentes faixas etárias (4 a 11, 12 a 17, 18 a 34, 35 a 59 e acima de 60 anos). Foram excluídos indivíduos diabéticos, gestantes, fumantes, edêntulos totais, indivíduos sob tratamento com fármacos que interfiram sobre o fluxo e composição salivar, pacientes usuários de prótese total, prótese parcial removível ou aparelhos ortodônticos, indivíduos que tenham sido submetidos à antibioticoterapia ou utilizado antiséptico nos últimos 45 dias. Amostras foram coletadas por enxagüe bucal e isolamento utilizando ágar Enterococcosel. Os isolados foram identificados pelo sistema API 20 Strep e avaliação da suscetibilidade aos antibióticos pela metodologia de diluição em ágar CLSI (2003). Considerando a população total (n=240), foram observados 16,6% dos indivíduos positivos para Enterococcus spp. na cavidade bucal com média de 121,73 UFC/ml de enxágüe bucal. Maior número de pacientes acima de 35 anos foram positivos. Observou-se diferença entre as contagens de enterococos dos grupos estudados (p=0,0019). O teste de Dunn indicou diferença entre o grupo de 12-17 anos em relação aos grupos 35-59 anos (p=0,0004) e acima de 60 anos (p=0,004). Não foi observada diferença estatisticamente significante entre as medianas de UFC/ml para os gêneros masculino e feminino (p=0,3645). Foi observada maior prevalência de E. faecalis em todos os grupos etários em relação as demais espécies (p=0.000). Do total de isolados 12% foram resistentes à vancomicina, 16% à amoxicilina, 54% à tetraciclina, 18% à ampicilina, 20% à cloranfenicol e 46% à eritromicina.The aim of this study was to evaluate the prevalence and antimicrobial susceptibility of Enterococcus spp. isolated from the oral cavity of individuals (n=240) with different ages (4 to 11, 12 to 17, 18 to 34, 35 to 59 and 60+ years). Patients with diabetes mellitus, pregnant women, smokers, edentulous, individuals under treatment with medications acting of salivary composition and flow, dentures and orthodontic devices users, and individuals under antibiotic or antiseptic use for the last 45 days were excluded. Samples were collected by oral rinses and the isolation was performed by using Enterococcosel agar. The isolates were identified by API 20 Strep system and the evaluation of antimicrobial susceptibility were performed by CLSI (2003) agar dilution methodology. Considering the total population (n=240), 16.6% of the individuals were positive to Enterococcus spp. in the oral cavity with mean value of 121.73cfu/ml. Higher number of patients over 35 years were positive. Differences of enterococci counts among the studied groups were observed (p=0.0019). Dunn’s test indicated differences between the group of 12 to 17 years in relation to the groups 35-59 years (p=0.0004) and over 60 years (p=0.004). No statistically significant difference between the median values of cfu/ml of male and female genders was observed (p=0.3645). E. faecalis was prevalent in all the age groups (p=0.000). From the total of isolates 12% were resistant to vancomycin, 16% to amoxicillin, 54% to tetracycline, 18% to ampicillin, 20% to chloramphenicol and 46% to erythromycin.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Evaluation of alternative methods for the disinfection of toothbrushes

The aim of this study was to evaluate alternative methods for the disinfection of toothbrushes considering that most of the previously proposed methods are expensive and cannot be easily implemented. Two-hundred toothbrushes with standardized dimensions and bristles were included in the study. The toothbrushes were divided into 20 experimental groups (n=10), according to microorganism considered and chemical agent used. The toothbrushes were contaminated in vitro by standardized suspensions of Streptococcus mutans, Streptococcus pyogenes, Staphylococcus aureus or Candida albicans. The following disinfectants were tested: 0.12% chlorhexidine digluconate, 50% white vinegar, a triclosan-containing dentifrice solution, and a perborate-based tablet solution. The disinfection method was immersion in the disinfectant for 10min. After the disinfection procedure, the number of remaining microbial cells was evaluated. The values of cfu/toothbrush of each group of microorganism after disinfection were compared by Kruskal-Wallis ANOVA and Dunn's test for multiple comparisons (5%). The chlorhexidine digluconate solution was the most effective disinfectant. The triclosan-based dentifrice solution promoted a significant reduction of all microorganisms' counts in relation to the control group. As to the disinfection with 50% vinegar, a significant reduction was observed for all the microorganisms, except for C. albicans. The sodium perborate solution was the less effective against the tested microorganisms. Solutions based on triclosan-containing dentifrice may be considered effective, nontoxic, cost-effective, and an easily applicable alternative for the disinfection of toothbrushes. The vinegar solution reduced the presence of S. aureus, S. mutans and S. pyogenes on toothbrushes

Prevalence of yeasts in the oral cavity of children treated with inhaled corticosteroids

The aim of this study was to observe the prevalence of Candida spp. in the oral cavity of children undergoing treatment with inhaled corticosteroids. Thirty children treated with inhaled corticosteroids and thirty control children were studied. Saliva samples were collected through oral rinses with phosphate buffered saline (PBS). The samples were plated on Sabouraud's dextrose agar and incubated at 37 degrees C for 48 h. After this period, the number of colony-forming units per ml (cfu/ml) of saliva was calculated. The isolates were identified by phenotypic characterization. Candida spp. was isolated from 43.33% of the samples of children treated with corticosteroids, with a mean of 780 cfu/ml of saliva, and from 30% of the samples of the control group, with a mean of 560 cfu/ml of saliva. No significant statistical difference was observed between the groups. C. albicans was the prevalent species in both groups, followed by C. guilliermondii, C. parapsilosis and C. stellatoidea. Furthermore, Rhodotorula rubra and C. lusitaniae were also isolated from the treated group. We concluded that there was no significant increase in the prevalence and number of Candida spp. in the oral cavity of children treated with inhaled corticosteroids

Experimental pathogenicity of Candida albicans and Candida dubliniensis with continuous and discontinuous fringes morphotypes

A possible correlation between the presence of discontinuous fringes and high virulence has been previously suggested. The aim of this study was to compare the pathogenicity of Candida albicans and Candida dubliniensis with continuous and discontinuous fringes morphotypes on mice. For C. albicans, two discontinuous fringe morphotype isolates (PN 69, PN 74), two continuous fringe morphotype isolates (N 60, N 33) and one reference strain were used. For C. dubliniensis, three discontinuous fringe morphotype isolates (97487, 97464, 97519), two continuous fringe morphotype isolates (97040, 98026) and one reference strain were used. Swiss male mice were inoculated with a standardised suspension of the microorganisms and observed for 35 days. The pathogenicity of the isolates was analysed according to parameters proposed previously. Three isolates were considered pathogenic: PN 74, N 60 and 98026. Strain N 60 killed the highest amount of mice (80%). Animals inoculated with C. albicans did not show differences on survival estimate. Candida dubliniensis 98026 was more pathogenic than samples 97464 and 97519. on the other hand, the sample 97487 showed a higher pathogenicity when compared with 97040 (Kaplan-Meier test, P = 0.008). Strains with continuous fringe morphotypes were also associated with Candida sp. virulence in vivo

Enterococcus species in the oral cavity: prevalence, virulence factors and antimicrobial susceptibility

Enterococci are considered as transient constituent components of the oral microbiome that may cause a variety of oral and systemic infections. As there is sparse data on the oral enterococcal prevalence, we evaluated the Enterococcus spp. and their virulence attributes including antimicrobial resistance in a healthy Brazilian cohort. A total of 240 individuals in different age groups were studied (children 4-11 yrs, adolescents 12-17 yrs, young adults 18-29 yrs, adults 30-59 yrs, elderly over 60 yrs). Oral rinses were collected and isolates were identified by API 20 Strep and confirmed by 16S rDNA sequencing. E. faecalis isolates, in particular, were evaluated for virulence attributes such as their biofilm formation potential, and susceptibility to antimicrobials and an antiseptic, chlorhexidine gluconate. A total of 40 individuals (16.6%) and 10% children, 4% adolescents, 14% young adults, 30% adults, and 25% elderly carried oral enterococci. The oral enterococcal burden in adolescents was significantly lower than in the adults (p = 0.000) and elderly (p = 0.004). The proportion of carriers was higher among females (p = 0.001). E. faecalis was the most frequent isolate in all the age groups (p = 0.000), followed by E. durans and E. faecium.Whilst all the clinical isolates were able to form biofilms, only a proportion of them were able to produce lipase (92%), hemolysin (38%), and gelatinase (39%). Of all the isolates 53.8% were resistant to tetracycline, 12.3% to amoxicillin, 16.0% to ampicillin, 20.8% to chloramphenicol and 43.4% to erythromycin. None of the isolates were resistant to vancomycin. Our data suggest that in this Brazilian cohort the oral cavity may act as a significant reservoir of rather virulent and antibiotic resistant enterococci, with an increasing degree of carriage in the adults and elderly. Hence clinicians should be cognizant of this silent reservoir of virulent enterococci that may pose a particular threat of nosocomial infection

In vitro adherence of Candida albicans isolated from patients with chronic periodontitis

Adherence is considered an extremely important virulence factor in yeast. Objective: The aim of this study was to analyze the adherence to epithelial cells of C. albicans isolated from patients with chronic periodontitis in comparison to healthy patients. Material and methods: Candida albicans cells isolated from individuals with chronic periodontitis (n=25) and healthy controls (n=25) were included in this study. Suspensions of C. albicans (10(6) cells/rnL) and epithelial cells (10(5) cells/mL) were mixed and incubated at 37 degrees C for 1 h. The number of yeasts adhered to 25 epithelial cells was counted. Results: The number of C. albicans cells adhered to epithelial cells was statistically higher in the chronic periodontitis group than in the control group (Student's t-test, p=0.000). Conclusion: The results of the present study suggest a higher Candida adherence of samples isolated from patients with chronic periodontitis

Phenotypic characterization of Candida spp. isolates from chronic periodontitis patients

Aim: Several typing methods for Candida spp. have been suggested in the literature in order to distinguish isolates for studies about the virulence or infection routes of these microorganisms and, in particular, for epidemiological purposes. The aim of this study was to establish a comparison between the phenotypic profile of oral Candida isolates from periodontitis patients and control individuals. Methods: The morphotyping and biotyping of 35 C. albicans isolates obtained from chronic periodontitis patients and 48 isolates from control individuals were performed. For morphotyping, the isolates were plated on malt extract agar and incubated for 10 days. Sixteen different morphotypes were observed for C. albicans, the most frequently observed being 0000 and 0001. Results: Biotype 0000 (complete absence of fringe) was most prevalent among the isolates obtained from periodontitis patients compared to those from control individuals, with statistical significance. Biotyping revealed 5 different biotypes with higher prevalence of the biotype 357 among the isolates from control and periodontitis groups. Conclusions: The results obtained by biotyping of the isolates did not permit to differentiate a characteristic model related to periodontal disease, whilst the morphotype 0000 was most frequently isolated from periodontitis patients