Enhanced Susceptibility Of Candida Albicans To Chlorhexidine Under Anoxia

Aim: Periodontal pockets can be colonized not only by bacteria, but also by Candida albicans. However, its role in periodontitis is unknown. This study evaluated the inhibitory performance of chlorhexidine digluconate under normoxic and anoxic conditions against 16 strains of C. albicans from periodontal pockets and other 20 from the oral mucosa. Methods: Strains were grown in normoxia and anoxia to adapt themselves to the different atmospheric conditions. Microdilution-based assays were carried out to determine the minimum concentrations of chlorhexidine that may restrain the conditioned candidal strains, in normoxia (normoxic MIC) and anoxia (anoxic MIC). The Mann-Whitney U test was used to evaluate the antimicrobial effect of chlorhexidine on C. albicans under normoxic and anoxic conditions (? = 0.05). Results: The normoxic MIC of chlorhexidine varied broadly from 150 to 1200 µg/mL, whereas its anoxic MIC varied narrower from 2.34 to 37.5 µg/mL. Regarding the origins of strains, no statistically significant differences (p > 0.05) were found. Conclusions: These results indicate that anoxic environmental conditions, compatible with periodontal pockets, tend to enhance C. albicans susceptibility to chlorhexidine.82105-11

Isoenzymatic genotyping of Staphylococcus aureus from dairy cattle and human clinical environments reveal evolutionary divergences

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

Staphylococcus aureus resistente à ampicilina em ambiente de 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.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

Electrophoretic Protein Patterns And Numerical Analysis Of Candida Albicans From The Oral Cavities Of Healthy Children.

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 < SD < or = 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 < or = SD < 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.45249-5

Padrões eletroforéticos de proteínas e análise numérica de Candida albicans isoladas da cavidade oral de crianças saudáveis

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

Dynamics of the seasonal airborne propagation of Staphylococcus aureus in academic dental clinics

Objective:&nbsp; 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

Conventional and alternative antifungal therapies to oral candidiasis

Candida-associated denture stomatitis is the most common form of oral candidal infection, with Candida albicans being the principal etiological agent. Candida adheres directly or via an intermediary layer of plaque-forming bacteria to denture acrylic. Despite antifungal therapy to treat denture stomatitis, infection is reestablished soon after the treatment ceases. In addition, many predisposing factors have been identified as important in the development of oral candidiasis, including malnourishment, common endocrine disorders, such as diabetis mellitus, antibacterial drug therapy, corticosteroids, radiotherapy and other immunocompromised conditions, such as acquired immunodeficiency syndrome (AIDS). These often results in increased tolerance to the most commonly used antifungals. So this review suggests new therapies to oral candidiasis.82483

Candida spp. biotypes in the oral cavity of school children from different socioeconomic categories in Piracicaba - SP, Brazil

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