The association between caries prevalence and clinical (presence of visible plaque in the labial surfaces of maxillary incisors), microbiological (salivary levels of mutans streptococci) and dietary variables was evaluated in 142 1.0- to 2.5-year-old children attending public day-care nurseries in the city of Piracicaba – São Paulo. A significant difference in caries prevalence was observed between those children with and without visible plaque (χ² = 12.08, p < 0.001). The mean ds (decayed surfaces) was significantly higher in children with visible plaque on the maxillary incisors than in children without it (p < 0.001). Mutans streptococci were detected in 114 (80.3%) of the children. A significantly higher caries prevalence was observed in children with high levels of mutans streptococci compared to children with low levels (χ² = 28.67, p < 0.001). The mean ds was significantly higher in children with levels of mutans streptococci greater than 50 CFU when compared to children with 0 CFU or 1–50 CFU of mutans streptococci (p < 0.05). Children who were either never breast-fed or only until 3 months exhibited a significantly higher caries prevalence than those breast-fed for a longer time (χ² = 4.11, p < 0.05). A significantly higher caries prevalence was also observed between children that used bottle containing milk with sucrose and cereal than children using bottle with milk with or without sucrose (χ² = 6.24, p < 0.05). Children who started to eat salty meals at or after 7 months of age showed a significant higher caries prevalence than children who started earlier (χ² = 10.30, p < 0.01). These data support the evidence of an association between caries prevalence in young children and mutans streptococci levels, clinical and dietary factors.

Eighty isolates of Actinobacillus actinomycetemcomitans from 30 Brazilian periodontitis patients were examined to determine the distribution of biotypes and in vitro antimicrobial susceptibility. Seventy-seven percent of the isolates belonged to biotype X. All A. actinomycetemcomitans isolates were susceptible to cefoxitin, imipenem and tetracycline.

Actinobacillus actinomycetemcomitans is implicated as the causative agent of localized juvenile periodontitis. This organism possesses a large number of virulence factors with a wide range of activities and also interfere with tissue repair. Fifty isolates of A. actinomycetemcomitans from 20 periodontal patients were examined to evaluate other putative virulence factors. In this study, the capsule, DNase, coagulase, fibrinolysin, proteolytic, haemolysin and bacteriocin production, haemagglutination, serum sensitivity, epithelial cells attachment, hydrophobicity and virulence of the A. actinomycetemcomitans isolates were evaluated. All the isolates were resistant to the different tested sera. 70% to 94% were alpha-haemolytics and agglutinated all blood types. Most of isolates produced antagonistic substances and they had a low hydrophobicity. None of the isolates was pathogenic for mice. Little is known as to wether these factors may act in the development of periodontal disease, and further studies are required for an application in pathogenic and systematic terms.

The aim of this investigation was to determine whether sublethal concentrations of chlorhexidine (Cx), hexetidine (Hx), cetylpyridinium chloride (Cc), sodium dodecyl sulfate (SDS), sanguinarine (Sg), sodium fluoride (NaF), and ammonium fluoride (NH₄F) could affect hydrophobicity and adhesion of Streptococcus sanguis and Streptococcus mutans to saliva-coated hydroxyapatite (S-HA). Determination of the minimum inhibitory concentrations (MICs) showed that both species were susceptible to all agents tested. Growth in the presence of sub-MIC concentrations of Cx, SDS, Cc, NaF, or NH₄F did not change significantly the hydrophobicity of S. sanguis cells when compared to the control which lacked any agent. However, growth in the presence of Hx or Sg resulted in a significant reduction in their hydrophobicity. Sub-MIC levels of SDS or Sg in the growth medium resulted in S. mutans cells with increased affinity for hexadecane compared with the control. The adherence of S. sanguis was changed significantly only by Hx or Sg, resulting in less cells adhering to S-HA. However, S. mutans cells previously incubated with NaF, NH₄F, or Sg showed a higher adherence to S-HA than the control. The mechanisms of interference with adherence are at present not completely understood. Thus, antimicrobial agents at sub-MIC concentrations can interfere selectively with hydrophobicity and/or adhesion of oral streptococci.

ZELANTE, F. et al Staphylococcus aureus na boca e no nariz de indivíduos sãos.Verificação de identidade entre as cepas isoladas. Rev. Saúde públ., S. Paulo, 16: 92-6, 1982. RESUMO:Material colhido do nariz e da boca (saliva e raspado lingual, isoladamente) de 130 indivíduos clinicamente sadios, permitiu caracterizar 47 (36,15%) deles como portadores de S. aureus, sendo 21 portadores exclusivamente bucais e 31 exclusivamente nasais. Tendo sido constatado que o nariz e a boca albergam cepas de diferentes fagotipos, foi verificado que a colheita simultânea de material de dois nichos distintos (saliva e língua, nariz e língua e nariz e saliva) proporcionava a determinação de maior número de portadores. Foi recomendado que, na detecção de portadores de S. aureus, os isolamentos devem ser feitos a partir de materiais colhidos simultaneamente das áreas nasal e bucal (saliva ou língua).

INTRODUÇÃOA detecção e controle de portadores de Staphylococcus aureus assume significativa importância quando se trata de profissionais da área de saúde e manipuladores de alimentos, devido a existência de cepas produtoras de enterotoxinas 1,5,7,13 .De forma geral, o grande número de pesquisas dirigidas a esse propósito preocupa-se, principalmente, com a detecção de portadores desse microrganismo nas fossas nasais e na pele 2,8,10,11,14,23,30 . Todavia, trabalhos de Knighton 16 (1962), Piochi e Zelante 22 (1973) e Zelante e col. 34 (1983) demonstraram que a cavidade oral se comporta com magnitude semelhante, como armazenadora e disseminadora de Staphylococcus aureus. Foi demonstrado, também, que as cepas que colonizam a mucosa lingual do homem diferem, quanto ao seu padrão fágico, daquelas isoladas das fossas nasais de um mesmo indivíduo, fator que potencializa a importância do estado de portador 29,33 .Dameto e Zelante 7 (1981), acompanhando durante quatro anos um mesmo grupo de portadores nasais, demonstraram a variação do padrão fágico das cepas isoladas, de sorte que somente um, dentre os integrantes daquele grupo, albergou o mesmo fagótipo durante toda a vigência do estudo. Tais observações reforçam a necessidade do controle constante nos indiví-duos considerados de elevado risco para a disseminação desse microrganismo.O isolamento de Staphylococcus aureus de fezes, relatado por Laurell e

No abstract

To investigate the significance of mast cells in the popliteal lymph node during the development of an inflammatory response, rats were inoculated with 12 x 10(7) colony-forming units of Staphylococcus aureus in the hind foot pad. Numerical changes in mast cells were then measured in the corresponding popliteal lymph node. Six days after inoculation, despite the enlargement of the responding lymph node, a marked decrease in granulated mast cell number, relative to the contralateral node, was observed in the cortical and medullary compartments. Popliteal lymph nodes from rats treated with compound 48/80 and then inoculated with S. aureus showed a higher cortical and medullary hypertrophic response and a significant increase in degranulated/weakly basophilic mast cell number in the lymph node tissue. The findings suggest that (1) Staphylococcus aureus induces a reduction in granulated mast cell number in the cortical and medullary compartments of regional lymph nodes; (2) pretreatment with compound 48/80 appears to contribute to the lymphoid cell proliferation and the hypertrophic response of lymph nodes induced by S. aureus; and (3) granulated mast cells have a regulatory role on lymphoid cell proliferation.