Abstract Objective Staphylococcus aureus strains can be disseminated during dental treatments and occasionally lead to the contamination and infection of patients and dentists, which is an important public health problem. The dynamics of the airborne propagation and the genetic diversity of S. aureus isolated in an academic dental clinic environment were investigated using isoenzyme typing. Material and Methods The isoenzymes of 44 previously reported isolates were obtained from fresh cultures and extracted using glass beads. Nine isoenzymes were investigated using multilocus enzyme electrophoresis (MLEE). The genetic diversity and relationship among the strains (electrophoretic type – ET) were determined using statistics previously described by Nei25 (1972) and the SAHN grouping method (UPGMA algorithm). Results Clonal pattern analyses indicated a high level of genetic polymorphism occurring among the 33 ETs, which were grouped into five taxa. Each taxon presented one or more clusters that were moderately related and that contained two or more identical/highly related isolates, revealing seasonal airborne propagation in these dental clinic environments. Conclusions These data suggest the occurrence of active microevolutionary processes in S. aureus as well as the possibility of environmental propagation during a 14-month time span. Such findings are important to show that multiuser academic dental clinics can retain certain strains that are spreadable to different niches.

ABSTRACT Background The genetic variability of 610 S. aureus isolates from the hands of professional dentists (A), dental clinic environment air (B), bovine milk from cows with and without mastitis (C), an insufflator for milking equipment (D) and milking environment air (E) was studied by isoenzyme genotyping and genetic and cluster analysis. Results Monoclonal and polyclonal patterns of S. aureus were detected in every bacterial population; however, isolates belonging to the same strain were not found among the populations, suggesting the genetic heterogeneity and the intrapopulation spread of strains. Genetic relationship analysis revealed the co-existence of highly related strains at low frequency among populations. Conclusion The data suggest that some strains can adapt and colonize new epidemiologically unrelated habitats. Consequently, the occurrence of an epidemiological genotypic identity can assume a dynamic character (spread to new habitats), however infrequently. A tendency of microevolutionary and genetic divergences among populations of S. aureus from human sources (AB) and bovine milk (DE), and especially the mammary quarter (C), is also suggested. This research can contribute to the knowledge on the distribution and dissemination of strains and the implementation of control measures and eradication of S. aureus in important dental clinic environments, as well as animal environments and dairy production.

Atualmente Staphylococcus aureus multirresistente é causa comum de infecções com altas taxas de morbidade e mortalidade mundialmente, o que direciona esforços científicos na busca de novos antimicrobianos. Neste estudo, nove extratos de Bidens pilosa (raiz, caule, flor e folhas) e de Annona crassiflora (casca do fruto, caule, folha, semente e polpa) foram obtidos com etanol:água (7:3, v/v) e suas atividades antibacteriana in vitro avaliadas através de difusão em agar e microdiluição em caldo contra 60 cepas de Oxacillin Resistant S. aureus (ORSA) e contra S. aureus ATCC 6538. Os extratos de B. pilosa e A. crassiflora inibiram o crescimento dos isolados ORSA em ambos os métodos. O extrato da folha de B. pilosa apresentou média dos diâmetros dos halos de inibição significativamente maior que a clorexidina 0,12%, contra os isolados ORSA, e os extratos foram mais ativos contra S. aureus ATCC (p < 0,05). Paralelamente, teste de toxicidade pelo método MTT e triagem fitoquímica foram avaliadas, e três extratos (raiz e folha de B. pilosa e semente de A. crassiflora) não apresentaram toxicidade. Por outro lado, as concentrações citotóxicas (CC50 e CC90) para os outros extratos variaram de 2,06 a 10,77 mg/mL. Observou-se variável presença de alcalóides, flavonóides, taninos e saponinas, apesar de total ausência de antraquinonas. Portanto, os extratos das folhas de B. pilosa revelaram boa atividade anti-ORSA e não exibiram toxicidade.

Currently multiresistant Staphylococcus aureus is one common cause of infections with high rates of morbidity and mortality worldwide, which directs scientific endeavors in search for novel antimicrobials. In this study, nine extracts from Bidens pilosa (root, stem, flower and leaves) and Annona crassiflora (rind fruit, stem, leaves, seed and pulp) were obtained with ethanol: water (7:3, v/v) and their in vitro antibacterial activity evaluated through both the agar diffusion and broth microdilution methods against 60 Oxacillin Resistant S. aureus (ORSA) strains and against S. aureus ATCC6538. The extracts from B. pilosa and A. crassiflora inhibited the growth of the ORSA isolates in both methods. Leaves of B. pilosa presented mean of the inhibition zone diameters significantly higher than chlorexidine 0.12% against ORSA, and the extracts were more active against S. aureus ATCC (p < 0.05). Parallel, toxicity testing by using MTT method and phytochemical screening were assessed, and three extracts (B. pilosa, root and leaf, and A. crassiflora, seed) did not evidence toxicity. On the other hand, the cytotoxic concentrations (CC50 and CC90) for other extracts ranged from 2.06 to 10.77 mg/mL. The presence of variable alkaloids, flavonoids, tannins and saponins was observed, even though there was a total absence of anthraquinones. Thus, the extracts from the leaves of B. pilosa revealed good anti-ORSA activity and did not exhibit toxicity.

The aim of this study was to evaluate the mutagenicity (clastogenicity/aneugenicity) of a glycolic extract of Ziziphus joazeiro bark (GEZJ) by the micronucleus assay in mice bone marrow. Antimutagenic activity was also assessed using treatments associated with GEZJ and doxorubicin (DXR). Mice were evaluated 24-48 h after exposure to positive (N-nitroso-N-ethylurea, NEU - 50 mg.kg-1 and DXR - 5 mg.kg-1) and negative (150 mM NaCl) controls, as well as treatment with GEZJ (0.5-2 g.kg-1), GEZJ (2 g.kg-1) + NEU and GEZJ (2 g.kg-1) + DXR. There were no significant differences in the frequencies of micronucleated polychromatic erythrocytes in mice treated with GEJZ and GEJZ + DXR compared to the negative controls, indicating that GEZJ was not mutagenic. Analysis of the polychromatic:normochromatic erythrocyte ratio revealed significant differences in the responses to doses of 0.5 g.kg-1 and 1-2 g.kg-1 and the positive control (NEU). These results indicated no systemic toxicity and moderate toxicity at lower and higher doses of GEZJ. The lack of mutagenicity and systemic toxicity in the antimutagenic assays, especially for treatment with GEZJ + DXR, suggested that phytochemical compounds in Z. joazeiro bark attenuated DXR-induced mutagenicity and the moderate systemic toxicity of a high dose of Z. joazeiro bark (2 g.kg-1). Further studies on the genotoxicity of Z. joazeiro extracts are necessary to establish the possible health risk in humans and to determine the potential as a chemopreventive agent for therapeutic use.

The genetic diversity of C. albicans oral isolates from 75 healthy schoolchildren from eight schools located in different geographic areas of Piracicaba city, São Paulo state, Brazil, was established using isoenzymes marker (Multilocus Enzyme Electrophoresis - MLEE) and cluster analysis. Patterns of monoclonal and polyclonal oral colonization by C. albicans within and between groups of schoolchildren were identified. However, significant divergence between the observed and the expected genotypic frequencies (Hardy-Weinberg equilibrium test) was not detected in the geographically adjacent groups, suggesting the hypothesis that populations of healthy schoolchildren do not correspond to the selection factor (differential survival) of strains. Two highly polymorphic and distantly genetically related taxa (A and B) were identified within the total population of yeasts, each contained subgroups (A1, A2, A3, A4, B1 and B2) and clusters of moderately related strains (from I to X), suggesting the existence of strains restricted or not to certain groups of geographically limited, healthy students. However, the coexistence of identical strains in healthy schoolchildren from the same school (geographically related) reinforces the hypothesis of oral transmission, where the sources of propagation could be explored. Furthermore, this could also be used in current and retrospective analyses of C. albicans isolated from immunocompetent and immunocompromised people, in order to detect commensal or potentially pathogenic yeast groups, predominantly in candidiasis, and in the development of strategies to prevent transmission or human propagation.

O objetivo desta pesquisa foi avaliar o grau de diversidade genética dentro e entre populações de C. albicans isoladas da cavidade bucal de crianças saudáveis brasileiras classificadas em cinco categorias socioeconômicas (A até E), através da análise de Eletroforese de Enzimas Multilocos (MLEE). Alta diversidade genética foi observada em todas as populações, as quais mostraram predominância de alguns subtipos de C. albicans (Tipos Eletroforéticos - ETs). Contudo, nenhuma correlação foi observada entre ET-específico e população-específica de crianças. A existência de um ou mais grupos de ET altamente relacionados foi mostrada pela análise de agrupamento, o que sugere a existência de rotas de propagação direta e indireta de C. albicans entre crianças saudáveis. Alterações microevolucionárias foram observadas em algumas populações de C. albicans isoladas de crianças que tiveram a mesma, ou muito próxima, condição socioeconômica. Além disso, baixa transição de subtipos de C. albicans podem estar ocorrendo entre certas populações de crianças provenientes de alta e média/alta, ou alta e média/baixa, ou média/alta e média/baixa, categorias socioeconômicas, o que pode ser esclarecido pelas suas próprias características socioeconômica e cultural.

The aim of this research was to evaluate the genetic diversity within and between C. albicans populations isolated from the oral cavity of healthy Brazilian children classified into five socioeconomic categories (A to E). Multilocus Enzyme Electrophoresis (MLEE) analysis was the method used to assess genetic diversity. High genetic diversity was observed in all populations that showed predominance of some C. albicans subtypes (Electrophoretic Types - ETs). However, no correlation was observed between a specific ET and a specific population of children. Clustering analysis showed one or more highly related ET clusters, suggesting the existence of indirect and direct propagation routes of C. albicans among healthy children. Microevolutionary changes were observed in some C. albicans populations isolated from children with the same or very similar socioeconomic condition. Furthermore, low transition of C. albicans subtypes can be occurring among certain populations of children coming from high and medium/high, or high and medium/low, or medium/high and medium/low socioeconomic categories, which can also be explained by their own socioeconomic and cultural characteristics.

O objetivo desta pesquisa foi avaliar o grau de diversidade genética dentro e entre populações de C. albicans isoladas da cavidade bucal de crianças saudáveis brasileiras classificadas em cinco categorias socioeconômicas (A até E), através da análise de Eletroforese de Enzimas Multilocos (MLEE). Alta diversidade genética foi observada em todas as populações, as quais mostraram predominância de alguns subtipos de C. albicans (Tipos Eletroforéticos - ETs). Contudo, nenhuma correlação foi observada entre ET-específico e população-específica de crianças. A existência de um ou mais grupos de ET altamente relacionados foi mostrada pela análise de agrupamento, o que sugere a existência de rotas de propagação direta e indireta de C. albicans entre crianças saudáveis. Alterações microevolucionárias foram observadas em algumas populações de C. albicans isoladas de crianças que tiveram a mesma, ou muito próxima, condição socioeconômica. Além disso, baixa transição de subtipos de C. albicans podem estar ocorrendo entre certas populações de crianças provenientes de alta e média/alta, ou alta e média/baixa, ou média/alta e média/baixa, categorias socioeconômicas, o que pode ser esclarecido pelas suas próprias características socioeconômica e cultural.

The aim of this research was to evaluate the genetic diversity within and between C. albicans populations isolated from the oral cavity of healthy Brazilian children classified into five socioeconomic categories (A to E). Multilocus Enzyme Electrophoresis (MLEE) analysis was the method used to assess genetic diversity. High genetic diversity was observed in all populations that showed predominance of some C. albicans subtypes (Electrophoretic Types - ETs). However, no correlation was observed between a specific ET and a specific population of children. Clustering analysis showed one or more highly related ET clusters, suggesting the existence of indirect and direct propagation routes of C. albicans among healthy children. Microevolutionary changes were observed in some C. albicans populations isolated from children with the same or very similar socioeconomic condition. Furthermore, low transition of C. albicans subtypes can be occurring among certain populations of children coming from high and medium/high, or high and medium/low, or medium/high and medium/low socioeconomic categories, which can also be explained by their own socioeconomic and cultural characteristics.

Foi avaliada a prevalência de Staphylococcus spp. e S. aureus no ambiente clínico odontológico, a produção de beta-lactamase e a susceptibilidade antibacteriana aos principais antibióticos utilizados na prática clínica. Durante 12 meses de coleta de amostras foram isolados 9775 UFC no meio de cultura AMS, demonstrando uma elevada quantidade de Staphylococcus spp. no ambiente clínico, provavelmente em decorrência da propagação de aerossóis. Um total de 3149 colônias (32,2%) foi sugestivo de estafilococos patogênicos. Coloração de Gram, teste de catalase, crescimento de colônias-malva sobre meio cromogênico e teste de coagulase confirmaram a identidade de 44 (0,45%) isolados de S. aureus. Destes, 35 isolados (79,5%) mostraram produção de beta-lactamase através de discos de CefinaseTM e resistência a ampicilina, eritromicina (7 isolados) e tetraciclina (1 isolado), sugerindo a existência de isolados multirresistentes. A avaliação do MIC de oxacilina através dos ensaios de Etest® mostrou padrões de susceptibilidade o que sugere a inexistência do gene mecA gene no DNA cromossômico. Estes resultados apontam para a necessidade de um maior conhecimento sobre os meios de contaminação e propagação deste microrganismo dentro da clínica odontológica.

The aim of this research was to evaluate the prevalence of Sthaphylococcus spp. and S. aureus in the odontological clinic environment (air), their production of beta-lactamase and antibacterial susceptibility to the major antibiotics utilized in medical particle. During 12 months of samples collect were isolated 9775 CFU by MSA medium suggesting a high amount of Staphylococcus spp. in the clinic environment which can appear through aerosols. A total of 3149 colonies (32.2%) were suggestive of pathogenic staphylococci. Gram coloration, catalase test, colony-mallow growing on chromogenic medium, and coagulase test confirmed the identity of 44 (0.45%) S. aureus isolates. Of these, 35 isolates (79.5%) showed production of beta-lactamase by CefinaseTM discs and resistance to ampicillin, erythromycin (7 isolates) and tetracycline (1 isolate) suggesting the existence of multiresistant isolates. The evaluation of the oxacillin MIC by Etest® assays showed susceptibility patterns suggesting the inexistence of the mecA gene in chromosomal DNA. These results point out to the need of a larger knowledge on the contamination means and propagation of this microorganism into the odontological clinic.

O objetivo da presente pesquisa foi analisar os graus de polimorfismos protéicos entre isolados de C. albicans provenientes de diversos sítios anatômicos de quarenta e dois pacientes clínicos, através do emprego da eletroforese em gel de poliacrilamida (SDS-PAGE) e análise numérica, a fim de se identificar subespécies e suas similaridades nos diversos nichos infecciosos. Culturas celulares foram desenvolvidas em meio YEPD, coletadas por centrifugação e lavadas com solução salina gelada. As proteínas celulares totais, foram extraídas por rompimento celular, usando pérolas de vidro e submetidas à técnica de SDS-PAGE. Após a eletroforese, as bandas de proteínas foram coradas com coomassie-blue e analisadas pelo conjunto de programas estatístico NTSYS-pc versão 1,70. Matrizes de similaridade e dendrogramas foram gerados pela aplicação do coeficiente de similaridade simple-matching e do algoritmo UPGMA, respectivamente. Os resultados obtidos revelaram vários subtipos de C. albicans e seus graus de similaridade (80% a 100%). Tais dados permitiram demonstrar que, certos pacientes podem estar infectados com dois ou mais subtipos de C. albicans em determinados sítios anatômicos (i.e. apenas na cavidade oral de pacientes imunocomprometidos, sangue ou secreção traqueal), ou ainda, dois ou mais pacientes podem estar infectados em sítios anatômicos idênticos (i.e. apenas em lavagem brônquica, urina, cavidade oral, secreção traqueal, secreção vaginal ou saliva saudável) com um mesmo subtipo de C. albicans. No entanto, dois ou mais pacientes também podem apresentar infecções em sítios correspondentes (i.e. apenas na cavidade oral de pacientes imunocomprometidos, sangue, secreção orofaríngea, cavidade oral, secreção traqueal, secreção vaginal e saliva saudável) por diferentes subtipos de C. albicans. Além disso, dois ou mais pacientes também podem estar infectados com subtipos idênticos ou não de C. albicans em diferentes sítios anatômicos (i.e.1. idênticos subtipos na secreção vaginal, secreção traqueal e urina; secreção abdominal e escarro; drenagem e cavidade oral; cateter e saliva saudável - i.e.2. diferentes subtipos em lavagem brônquica, secreção orofaríngea, secreção pulmonar, cavidade oral de pacientes imunocomprometidos e sangue). Dados complementares envolvendo amostras de C. albicans isoladas de vários sítios anatômicos de pacientes imunocompetentes ou imunocomprometidos (antes, durante e após terapias específicas) e seus familiares ou trabalhadores hospitalares, deverão ser obtidos a fim de se estabelecer as possíveis fontes de colonização por esses microrganismos. De modo geral, os perfis de proteínas totais obtidos por SDS-PAGE associados com análise numérica computadorizada, permitem a obtenção de critérios adicionais para os estudos epidemiológicos e taxonômicos de C. albicans.

The aim of the present research was to evaluate the protein polymorphism degrees among forty-eight C. albicans isolates from fourteen anatomical sites of clinical patients by polyacrylamide gel electrophoresis (SDS-PAGE) and numerical analyzes, in order to identify subspecies and their similarities in some infectious niches. Cell cultures were grown in YEPD medium, collected by centrifugation, and washed in cold saline solution. The whole-cell proteins were extracted by cell disruption using glass beads and submitted to SDS-PAGE technique. After electrophoresis, the protein bands were stained with coomassie-blue and analyzed by statistics package NTSYS-pc version 1.70 software. Similarity matrixes and dendrograms were generated by application of similarity coefficient of simple matching and UPGMA algorithm, respectively. The results obtained showed several C. albicans subtypes and their similarity degrees (80% to 100%). Such data showed that same patients may be infected by two or more C. albicans subtypes in certain anatomical sites (i.e. only in oral cavity of immunocompromised patients, blood, or tracheal secretion), or yet, two or more patients can be infected in identical anatomical sites (i.e. bronchial washing, urine, oral cavity, tracheal secretion, vaginal secretion, and healthy saliva) with a same C. albicans subtype. However, two or more patients also can show infections in corresponding sites (i.e. oral cavity of immunocompromised patients, blood, oropharyngeal secretion, oral cavity, tracheal secretion, vaginal secretion, and healthy saliva) by different C. albicans subtypes. Besides, two or more patients also can be infected with identical or different C. albicans subtypes in different anatomical sites (i.e.1. identical subtypes in vaginal secretion, tracheal secretion, and urine; abdominal secretion and spittle; drainage and oral cavity; catheter and healthy saliva - i.e.2. subtypes different in bronchial washing, oropharyngeal secretion, pulmonary secretion, oral cavity of immunocompromised patients, and blood). Complementary studies involving C. albicans sample isolated from several anatomical sites of immunocompetent or immunocompromised patients (before, during and after specifics therapies) and their families or hospital workers must be done in order to establish the sources of C. albicans colonization. The whole-cell proteins profile performed by SDS-PAGE associated with computer-assisted numerical analysis may provide preliminary criteria for taxonomic and epidemiological studies of such microorganisms.

O objetivo da presente pesquisa foi avaliar os graus de polimorfismos protéicos entre setenta e cinco linhagens de C. albicans isoladas da cavidade oral de crianças saudáveis provenientes de cinco categorias socioeconômicas e oito escolas (particulares e públicas) do município de Piracicaba, Estado de São Paulo, a fim de identificar subespécies de C. albicans e suas similaridades em grupos de populações infantis e estabelecer suas possíveis rotas de disseminação. Culturas celulares foram desenvolvidas em meio YEPD, coletadas por centrifugação e lavadas com solução salina gelada. As proteínas celulares totais foram extraídas por rompimento celular usando pérolas de vidro e submetidas à técnica de SDS-PAGE. Após a eletroforese, as bandas de proteínas foram coradas com Coomassie-blue e analisadas pelo conjunto de programas estatísticos NTSYS-pc versão 1.70. Matriz de similaridade e dendrograma foram gerados, pela aplicação do coeficiente de similaridade de Dice e do algoritmo UPGMA, respectivamente, os quais permitiram avaliar os graus de polimorfismo ou similaridade intra-específico, baseados nos padrões eletroforéticos de proteínas totais de isolados orais de C. albicans. Um total de 13 principais fenons (grupos) foi analisado de acordo com suas características homogêneas (categoria socioeconômica e/ou escola idênticas) e heterogêneas (categorias socioeconômicas e/ou escolas diferentes). Com relação ao aspecto epidemiológico socioeconômico, as composições dos grupos mostraram alta similaridade (0.788 < S D < 1.0) entre algumas linhagens de C. albicans isoladas de crianças saudáveis independentemente de suas camadas socioeconômicas (alta, média e baixa). Isolados de alta similaridade não foram encontrados nas cavidades orais de crianças saudáveis pertencentes às camadas sociais A e D, B e C, ou C e E. Isto pode ser explicado pela ausência de uma rota de disseminação entre estas crianças. Geograficamente, algumas crianças saudáveis entre escolas idênticas e diferentes (particulares e públicas) também são portadoras de linhagens semelhantes, mas tal similaridade não foi encontrada entre outros de determinadas escolas. Esses dados podem refletir uma rota de disseminação restrita destes microrganismos em alguns grupos de escolares saudáveis, a qual pode ser dependente da categoria socioeconômica ou local geográfico de cada criança. Em contraste à alta similaridade, a baixa similaridade ou alto grau de polimorfismo (0.499 < S D < 0.788) dos perfis protéicos foi demonstrado em 23 (30,6%) isolados orais de C. albicans. Considerando o aspecto epidemiológico social, 42,1%, 41,7%, 26,6%, 23,5% e 16,7% foram isolados de crianças provenientes das categorias socioeconômicas A, D, C, B e E, respectivamente, e geograficamente, 63,6%, 50%, 33,3%, 33,3%, 30%, 25% e 14,3% foram isolados de crianças provenientes das escolas LAE, MA, CS, AV, HF, FMC e MEP, respectivamente. Tais resultados sugerem um maior grau de polimorfismo entre algumas linhagens isoladas de crianças saudáveis independentemente de suas camadas sociais ou locais geográficos. Estudos complementares envolvendo escolares saudáveis e seus familiares, professores, serventes, hábitos nutricionais e de higiene deverão ser realizados a fim de estabelecer as fontes de tais padrões de colonização em grupos de populações de crianças saudáveis. Os perfis de proteínas totais obtidos por SDS-PAGE associados com análise numérica computadorizada podem proporcionar critérios adicionais para os estudos epidemiológicos e taxonômicos de C. albicans.

The aim of this research was to evaluate the protein polymorphism degree among seventy-five C. albicans strains from healthy children oral cavities of five socioeconomic categories from eight schools (private and public) in Piracicaba city, São Paulo State, in order to identify C. albicans subspecies and their similarities in infantile population groups and to establish their possible dissemination route. Cell cultures were grown in YEPD medium, collected by centrifugation, and washed with cold saline solution. The whole-cell proteins were extracted by cell disruption, using glass beads and submitted to SDS-PAGE technique. After electrophoresis, the protein bands were stained with Coomassie-blue and analyzed by statistics package NTSYS-pc version 1.70 software. Similarity matrix and dendrogram were generated by using the Dice similarity coefficient and UPGMA algorithm, respectively, which made it possible to evaluate the similarity or intra-specific polymorphism degrees, based on whole-cell protein fingerprinting of C. albicans oral isolates. A total of 13 major phenons (clusters) were analyzed, according to their homogeneous (socioeconomic category and/or same school) and heterogeneous (distinct socioeconomic categories and/or schools) characteristics. Regarding to the social epidemiological aspect, the cluster composition showed higher similarities (0.788 < S D < 1.0) among C. albicans strains isolated from healthy children independent of their socioeconomic bases (high, medium, or low). Isolates of high similarity were not found in oral cavities from healthy children of social stratum A and D, B and D, or C and E. This may be explained by an absence of a dissemination route among these children. Geographically, some healthy children among identical and different schools (private and public) also are carriers of similar strains but such similarity was not found among other isolates from children from certain schools. These data may reflect a restricted dissemination route of these microorganisms in some groups of healthy scholars, which may be dependent of either socioeconomic categories or geographic site of each child. In contrast to the higher similarity, the lower similarity or higher polymorphism degree (0.499 < S D < 0.788) of protein profiles was shown in 23 (30.6%) C. albicans oral isolates. Considering the social epidemiological aspect, 42.1%, 41.7%, 26.6%, 23.5%, and 16.7% were isolates from children concerning to socioeconomic categories A, D, C, B, and E, respectively, and geographically, 63.6%, 50%, 33.3%, 33.3%, 30%, 25%, and 14.3% were isolates from children from schools LAE (Liceu Colégio Albert Einstein), MA (E.E.P.S.G. "Prof. Elias de Melo Ayres"), CS (E.E.P.G. "Prof. Carlos Sodero"), AV (Alphaville), HF (E.E.P.S.G. "Honorato Faustino), FMC (E.E.P.G. "Prof. Francisco Mariano da Costa"), and MEP (E.E.P.S.G. "Prof. Manasses Ephraim Pereira), respectively. Such results suggest a higher protein polymorphism degree among some strains isolated from healthy children independent of their socioeconomic strata or geographic sites. Complementary studies, involving healthy students and their families, teachers, servants, hygiene and nutritional habits must be done in order to establish the sources of such colonization patterns in population groups of healthy children. The whole-cell protein profile obtained by SDS-PAGE associated with computer-assisted numerical analysis may provide additional criteria for the taxonomic and epidemiological studies of C. albicans.

Duzentos e trinta e nove crianças brasileiras foram estudadas, distribuídas em cinco categorias socioeconômicas distintas (A a E). As amostras de saliva foram analisadas avaliando-se o fluxo salivar, pH, capacidade tampão e parâmetros microbianos. Os resultados mostraram Candida em 47,3% da amostra total. A espécie mais encontrada foi C. albicans em todas as categorias socioeconômicas seguidas por C. tropicalis, C. krusei e C. parapsilosis. A saliva e os parâmetros de investigacão clínicos como a proporcão de secreção, capacidade tampão e CFU/ml de Candida não mostraram nenhuma correlação estatística entre estes parâmetros. A freqüência de Candida não diferiu substancialmente entre os grupos; no entanto elas foram mais acentuadas entre as categorias B e C. Entre todas as espécies, C. albicans foi a mais prevalente. Somente 5% das amostras mostraram mais de uma espécie e revelaram a presença de C. albicans associada com C. tropicalis, C. Parapsilosis ou C. krusei. Foi possível detectar uma correlação significante entre os índices de cárie e as categorias socioeconômicas. As categorias A e E mostraram índices de cárie aumentados; no entanto, a amostra da população foi considerada de risco de cárie baixo. Não havia nenhuma correlação positiva entre Candida e risco de cárie.

Two hundred and thirty-nine (239) Brazilian children, distributed into five distinct socioeconomic categories (A to E) were studied. Saliva samples were analyzed as to flow rate, pH, buffer capacity and microbial parameters. The results revealed the presence of Candida spp. in 47.3% of the samples. The most commonly isolated species was C. albicans, in all socioeconomic categories, followed by C. tropicalis, C. krusei and C. parapsilosis. There was no statistical correlation between secretion rate, buffer capacity and Candida spp. CFU/ml. The prevalence of Candida spp. did not differ substantially among the groups; however the microorganisms were more detected in categories B and C. Among all species, C. albicans was the most prevalent. Only 5% of the sample presented more than one species - C. albicans associated with C. tropicalis, C. parapsilosis or C. krusei. It was possible to detect a significant correlation between caries indices and the socioeconomic categories. All categories presented increased caries indices; however the studied population was considered of low caries risk. There was no positive correlation between the presence of Candida and caries risk in the analyzed population.