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G Nakazato

Publications and source records attributed to G Nakazato.

12 recordsLinked to original sources
PubMed2004

Attaching and effacing Escherichia coli isolated from dogs in Brazil: characteristics and serotypic relationship to human enteropathogenic E. coli (EPEC).

Escherichia coli isolates recovered from 182 fecal specimens from dogs up to five months old from the cities of São Paulo and Campinas, SP, Brazil, were examined by polymerase chain reaction (PCR) for several virulence factors and properties. The eae gene was found in 23 isolates of E. coli from 22 dogs, 19 of 146 (13%) from dogs with diarrhea and 3 of 36 (8.3%) from dogs with no diarrhea. Two different eae+ isolates were recovered from one dog with diarrhea. Isolates from two dogs with diarrhea harbored the bfpA gene, and none of the isolates possessed genes for enterotoxins, the EAF plasmid or Shiga toxins. PCR showed that, among the 23 isolates, eight were positive for beta intimin, six for gamma, two for, one for alpha, one for kappa, and five showed no amplification with any of the nine pairs of specific intimin primers used. PCR also showed that the LEE (locus of enterocyte effacement) was inserted in selC in four isolates, likely in pheU in seven isolates, and in undetermined sites in twelve isolates. Fifteen isolates adhered to HEp-2 cells and were fluorescence actin staining (FAS) positive. The predominant adherence pattern was the localized adherence-like (LAL) pattern. The eae-positive isolates belonged to a wide diversity of serotypes, including O111:H25, O119:H2 and O142:H6, which are serotypes that are common among human EPEC. These results confirmed the presence of EPEC in dogs (DEPEC) with and without diarrhea. The virulence factors found in these strains were similar to those in human EPEC, leading to the possibility that EPEC may move back and forth among human and canine populations.

Adhesins, Bacterial↗
PubMed2003

Clonal distribution of an atypical MRP+, EF*, and suilysin+ phenotype of virulent Streptococcus suis serotype 2 strains in Brazil.

Streptococcus suis is considered one of the most important bacterial swine pathogens worldwide. The distribution of the 35 described serotypes in diseased animals may vary in different regions. Data regarding S. suis isolation from pigs in South America is not available. In the present study, 51 isolates of S. suis recovered in pure culture or as the predominant species from diseased animals in Brazil, were analyzed. These isolates were classified as serotypes 2 (58.8%), 3 (21.5%), 7 (13.7%), 1 (3.9%), and 14 (2%). Serotype 2 isolates were further studied for their production of virulence-related proteins muramidase-released protein (MRP), extracellular factor (EF), and suilysin. In addition, the genetic diversity was studied by randomly amplified polymorphic DNA. All but 1 of the serotype 2 isolates showed a clonal distribution of an atypical phenotype (MRP+, EF*, suilysin+), different from the known European (MRP+, EF+, suilysin+), and North American (MRPv, EF-, suilysin-), phenotypes.

Animals↗
PubMed2002

Microbiological comparative study of isolates of Edwardsiella tarda isolated in different countries from fish and humans.

It is difficult to use tissue culture assays to investigate adherence and other properties of Edwardsiella tarda because the organism is invasive and produces a potent hemolysin. We therefore relied on polymerase chain reaction (PCR) to determine the occurrence of genes for enterotoxins (LT-I, EAST-1), Shiga toxin (Stx-1, Stx-2), cytotoxic necrotizing factors (CNF-1, CNF-2), aerobactin, invasion plasmid of enteroinvasive Escherichia coli, EPEC adherence factor (EAF), intimin (Eae), enterohemolysin (EntHly) and hemolysin (Hly) in 53 isolates of E. tarda from humans and fish from several countries. All isolates were negative for all genes investigated by PCR. Adhesion to and invasion of HeLa cells were determined by using the unusually short incubation time of 1h or 30 min. All isolates adhered and invaded in these tests. Finally, a random amplified polymorphic DNA (RAPD) test distinguished, with a few exceptions, isolates of human and fish origin.

Animals↗
PubMed1990

[Studies on plaque formed on implants].

In vivo plaque formation on implant materials was studied. When different implant materials were set on the gingiva, the number of adhering viable bacteria depended on material surface properties 4 hours after setting, but not 48 hours after setting. The formation of pellicle-like thin layers and subsequent covering by lamellarly formed plaque were observed on the surfaces of all materials. Streptococcus species were predominant at the 4-hour setting time but anaerobes increased at the 48-hour setting time; this was common to all materials. The results indicate that surface properties of the implants influence early bacterial adherence, but do not influence bacterial flora or plaque maturation. The subgingival microflora at the neck of implants with clinically normal peri-implant tissues was compared with that at the neck of natural teeth. The bacterial isolates were classified based on their biochemical characteristics. For the spirochaetes, the number was counted directly under light microscopic observation. The most predominant bacterial species was Streptococcus, followed by Actinomyces, Neisseria and then Capnocytophaga at both sites. The ratio of spirochaetes in the microflora was extremely low for both the implant and natural tooth. Such a bacterial distribution pattern closely resembled the hitherto-reported distribution of bacteria existing in a healthy gingival crevicular. This suggested that the microflora in plaque at the neck of a normal implant is basically similar to that at the neck of a natural tooth. In conclusion, plaque formation on implant materials was not influenced by their surface properties in actual oral cavity.

Actinomyces↗
PubMed1989

Effects of Tween 80 and sodium fluoride on extracellular glucosyltransferase production and membrane lipids of Streptococcus mutans.

1. Both Tween 80 and sodium fluoride significantly enhanced total extracellular glucosyltransferase activities of Streptococcus mutans. 2. Water-insoluble and water-soluble glucan formation were uniformly increased by Tween 80, whereas fluoride stimulated only water-soluble glucan formation. 3. Elevated glucan formation was due to an increase in enzymes secreted from bacterial cells. 4. Fatty acid composition and phospholipid content in bacterial membrane were changed by Tween 80, although sodium fluoride scarcely showed these changes. 5. Comparative results suggest that modulation of membrane lipids participates in mutansucrase production but not in dextransucrase production of S. mutans.

Glucosyltransferases↗
PubMed1989

[Study on air-powder abrasive system for prosthetic clinical application. 3. Bacterial adherence to the air-powder abraded metal surface].

The purpose of this study is to investigate the relation between the metal surface texture and bacterial adherence. The surface of Au-Ag-Pd alloy was treated with or without air-powder abrasion. Seven standard strains and two clinical isolates were used. The alloys were mixed with [6-3H]-thimidine labelled bacteria. The radioactivity was measured with a scintilation counter. Streptococcus sanguis and clinical isolated Bacteroides gingivalis were adhered in a larger amount to the air-powder abraded alloy surface than to nonabraded alloy surface. These results indicated that careful consideration is needed for application of air-powder abrasive system on metal crown with secondary caries and periodontal disease.

Bacterial Adhesion↗
PubMed1989

[Antibacterial actions of denture base resin on oral bacteria].

Antibacterial action of various denture base resins on thirteen species of bacteria were studied in vitro. Antibacterial effect of 5% tannin-fluoride preparation, 5% tannic acid and 5% chlorhexidine added to resins on these thirteen bacterial species were also investigated using heat-curing denture base resins. Fresh microwave-curing resin and pour-type resin each showed an antibacterial action on one bacterial strain. Fresh self-curing resins had antibacterial actions on several bacterial strains. However, after storage in water at 37 degrees C for one week, antibacterial action of microwave-curing and pour-type resin were diminished and self-curing resins partially lost their antibacterial actions. Denture base resin containing tannin-fluoride preparation or tannic acid showed an antibacterial effect on one bacterial strain. On the other hand, denture base resin containing chlorhexidine had an antibacterial action on eleven bacterial strains. However, color and mechanical properties of the drug-containing resins were not satisfactory.

Bacteria↗
PubMed1989

In vivo plaque formation on implant materials.

Plaque formation was studied in vivo by setting different implant materials on gingiva. The number of adhering viable bacteria depended on material surface properties 4 hours after setting, but not 48 hours after setting. The formation of pellicle-like thin layers and subsequent covering by lamellarly formed plaque were observed on the surfaces of all materials. Streptococcus species were predominant at the 4-hour setting time and anaerobes increased at the 48-hour setting time; this was common to all materials. The results indicate that surface properties of the implants influence early bacterial adherence, but do not influence bacterial flora or plaque maturation.

Adult↗