Compensatory levels of salivary IgM anti-Streptococcus mutans antibodies in IgA-deficient patients.

The protective role of salivary IgA in dental caries has not been completely demonstrated, so, in order to elucidate this point, we evaluated 15 totally and partially IgA-deficient children in terms of the following variables: dental caries indexes, bacterial plaques, number of Streptococcus mutans and Lactobacillus in the saliva, and titers of IgA, IgG and IgM anti-Streptococcus mutans antibodies in the saliva. Age-matched healthy children served as the control group. IgA-deficient children showed caries scores lower than those of the healthy children; in addition, no statistical difference was found between amount of dental plaque and numbers of the bacteria in saliva. The totally IgA-deficient children presented IgM in levels much higher than the healthy children (p < 0.05). These data could indicate a compensation for the IgA deficiency by IgM.

Oral species of Fusobacterium from human and environmental samples.

PURPOSE: The aim of this study was the characterization and identification of oral Fusobacterium in patients with and without periodontal disease, and from spittoons and air-water syringes. The antimicrobial susceptibility of this bacterium was evaluated. METHOD: Subgingival samples were taken using sterilized absorbent paper points. Spittoon samples were collected using sterile swabs around the drain area with shut off, and air-water syringe samples by washing the tip with Ringer solution. Samples were transferred in tubes under CO2 flux. Diluted samples were inoculated on to Omata and Disraely agar and blood agar plates, which were incubated in anaerobiosis, at 37 degrees C, for 4 days. Bacterial species were identified biochemically. MIC was determined using an agar dilution method. RESULTS: Periodontal patients, healthy subjects, spittoons and air-water syringes were 80%, 67.6%, 37.8% and 3.3% positive to Fusobacterium, respectively. Clindamycin, imipenem, lincomycin, metronidazole and tetracycline were active against all human and environmental isolates. Eighteen isolates resistant to ampicillin or penicillin G produced beta-lactamases. The presence of human oral bacteria in items of dental equipment supports the hypothesis that such equipment may serve as a vehicle for the transmission of pathogenic organisms. CONCLUSION: Pieces of dental equipment may serve as a vehicle for the transmission of oral pathogenic organisms.

The immediate and long-term effects of invasive and noninvasive pit and fissure sealing techniques on the microflora in occlusal fissures of human teeth.

The purpose of this study was to evaluate the effect of acid conditioning and occlusal sealant on microbial colonization of pit and fissures submitted to ameloplasty or left intact. Human enamel blocks containing fissures prepared from the occlusal surfaces of unerupted third molars were implanted in occlusal fillings in molars of 12 patients for seven, 30, 60, and 120 days. After seven days of exposure to the oral environment, the pit and fissure blocks were removed and found to be colonized, mainly with gram-positive coccal flora. The acid-etching procedure itself reduced the number of cultivable microorganisms by about 95%. Subsequent application of occlusal sealant caused a gradual decrease of the remaining viable microorganism throughout the experiment. Despite the decrease of 100% after acid etching in most of the fissures submitted to ameloplasty, the occlusal sealant did not lead to a subsequent significant reduction.

[Simultaneous occurrence of enterotoxigenic Staphylococcus aureus on the hands, mouth and feces of asymptomatic carriers]. / Ocorrência simultânea de Staphylococcus aureus enterotoxigênicos nas mãos, boca e fezes em portadores assintomáticos.

One hundred and twelve asymptomatic individuals were analysed with regard to the simultaneous incidence of Staphylococcus aureus on their hands and in their nose, mouth and stools, in the city of S. Paulo (Brazil). A total of 40 (35.7%) individuals were detected as carriers of this microorganism. Among these carriers, 27 (67.5%) were positive in only one of the four niches studied, 8 (20.0%) in two and 5 (12.5%) in three niches. They were identified 113 Staphylococcus aureus strains, and 28 (24.8%) of these strains, isolated from 9 (22.5%) carriers, produced enterotoxin. Of these strains, 7 (25.0%) produced type A enterotoxin, 6 (21.4%) of type B, 11 (39.3%) type C and 4 (14.3%) produced both type A and C. The phage typing of the 113 Staphylococcus aureus strains revealed the predominance of the strains lysed by phages belonging to the Group I/III/NC (16.8%). The results obtained did not demonstrate the simultaneous incidence of Staphylococcus aureus strains in samples collected from mouth, hands and stools of the group studied.

[The first isolation of Mycoplasma pneumoniae in Panama]. / Primer aislamiento de Mycoplasma pneumonia en Panamá.

Mycoplasma pneumoniae was isolated for first time in Panama and identified from a nine years old girl with pneumonia. SP4 medium was used to isolate the bacteria. Confirmatory serological results were obtained by indirect immunofluorescence and were also suggested by the presence of cryoagglutinins in the sera of this patient. DNA hybridization tests (Gen--Probe) were carried out.

Distribution of biotypes and antimicrobial susceptibility of Actinobacillus actinomycetemcomitans.

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.

Occurrence of microorganisms at different levels of the pulp. Contribution to endodontic techniques.

Microorganisms were absent in the remaining pulp stumps of twenty teeth which had been exposed to caries and contaminated at the pulpal chamber level. We have demonstrated that microorganisms are not carried to the deepest areas of the pulp when the basic procedure is strict antisepsis applied to the living pulp stump. A sterile and living pulp stump wound contributes to an adequate biologic sealing of the apical foramen. Of all the isolated microorganisms, the alpha hemolytic Streptococcus was most frequently found in all examined cases, in pure or mixed cultures, demonstrating once again he prodominance of that type of microorganism when pulpal injury occurs.

Lymphatic mast cell response and effect of compound 48/80 on popliteal lymph node reaction in rats following intracutaneous injection of Staphylococcus aureus.

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.

Effects of subinhibitory concentrations of chemical agents on hydrophobicity and in vitro adherence of Streptococcus mutans and Streptococcus sanguis.

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.

[Anti-rabies vaccination. Comparative analysis of the responses of Flury Hep, Fuenzalida, and inactivated Flury Hep vaccines]. / Contribuição ao estudo da vacinação anti-rábica. Análise comparativa das respostas das vacinas Flury Hep, Fuenzalida e Flury Hep inativada.

The authors verified the following: The FLURY HEP vaccine, with modified virus, confers a higher level of protection when applied by intracerebral route in laboratory animals. With an equal number of viral particles of FLURY HEP modified virus and fixed virus (FUENZALIDA type vaccine), inoculated intracerebrally and intramusculary, a better protection was obtained with the first kind of vaccine, specially by intracerebral route. These conditions suggest the possibility of replication of modified HEP virus in the cells of the central nervous system. The results show that the concentration of neutralizing antibodies in the serum is not the only responsable for protection, but suggests the possibility of factors or of cellular immunity acting in the animal's protection against rabies.

Association between caries prevalence and clinical, microbiological and dietary variables in 1.0 to 2.5-year-old Brazilian children.

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 (chi2 = 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 (chi2 = 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 (chi2 = 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 (chi2 = 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 (chi2 = 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.