Revista clínica de periodoncia, implantología y rehabilitación oral, Dec 1, 2017
Trabajo de invesTigación distribución gen fimA de Porphyromonas gingivalis en pacientes chilenos ... more Trabajo de invesTigación distribución gen fimA de Porphyromonas gingivalis en pacientes chilenos con periodontitis crónica
A strain of Shigella flexneri producing bacteriocin was isolated from a patient with diarrhea. Th... more A strain of Shigella flexneri producing bacteriocin was isolated from a patient with diarrhea. The main objective of this study was to isolate and partially characterize the bacteriocin. The producing microorganism was identified using biochemical, serological, and molecular methods. The lethal activity of the S. flexneri strain was studied using the drop method. This bacterial strain showed activity against different strains of E. coli and B. fragilis. Using immunological techniques, it was determined that S. flexneri belongs to serotype 2a, and by PCR, the presence of the ipaH plasmid was determined. By chromatographic techniques, it was determined that the bacteriocin is a peptide of high purity with a molecular weight of 66294.094 Da. The amino acid composition and sequence were determined by the Edman reaction, and a sequence of 619 amino acid residues was obtained. Only in five positions of this sequence, the amino acid glutamine changed to glutamic acid with respect to colici...
Currently, implant rehabilitation requires more than successful osseointegration, studies have de... more Currently, implant rehabilitation requires more than successful osseointegration, studies have described the need for a harmonious relationship between the levels of periimplant tissue and the already existing dentition to achieve an aesthetic and functional restoration. This can be accomplished with a careful balance of parameters such as the morphology and surface of the implant, the conditions of the receiving tissue, the surgical technique, the prosthesis design and the way in which the load is applied.1
Clinical implant dentistry and related research, Jan 15, 2018
In implant rehabilitation, a microspace is created at the abutment-implant interface (AII). Previ... more In implant rehabilitation, a microspace is created at the abutment-implant interface (AII). Previous research has shown that oral microbiome can proliferate in this microspace and affect periimplant tissues, causing inflammation in peri-implant tissues. Preventing microbial leakages through the AII is therefore an important goal in implantology. To determine the presence of marginal bacterial microleakage at the AII according to the torque applied to the prosthetic implant in vitro. Twenty-five Ticare Inhex internal conical implants (MG Mozo-Grau, Valladolid, España) were connected to a prosthetic abutment using torques of <10, 10, 20, 30, and 30 N and then sealed. The samples were submitted to cycles of occlusal loads and thermocycling, then one sample of each group was observed by micro TC, while the rest were mounted on devices according to the bacterial leakage model with Porphyromonas gingivalis. Bacterial leakage was observed only in the <10 and 10 N torque samples, and ...
The objective was to analyse the antibacterial ability of members of the intestinal microbiota of... more The objective was to analyse the antibacterial ability of members of the intestinal microbiota of Oncorhynchus mykiss specimens on several bacterial target strains that contaminate food and cause disease in humans. Bacterial colonies from an intestinal portion of the 20 specimens of O. mykiss were obtained in different culture media. Several of the colonies showed antibacterial action on different target strains. The bacterial species with the highest antagonistic capacity were Hafnia alvei and Lactococcus lactis and the more susceptible target strains were Aeromonas hydrophila, Listeria monocytogenes and Escherichia coli. Moreover, it was shown that all the antibacterial substances were susceptible to the action of various proteolytic enzymes. The detection of substances of a proteinaceous nature, possibly bacteriocins produced by bacteria of the intestinal microbiota of O. mykiss, allows further study of these products to establish biotechnological developments in the area of heal...
To detect S. mutans producers of mutacins and bacteriocins like substances (BLIS) from saliva of ... more To detect S. mutans producers of mutacins and bacteriocins like substances (BLIS) from saliva of participants with low, moderate, and high salivary counts. 123 strains of S. mutans were obtained from participants with low, moderate, and high salivary counts (age 18 and 20 years old) and their antibacterial capacity analyzed. By using PCR amplification, the expression levels of mutacins and BLIS genes were studied (expressed in arbitrary units/ml) in all three levels. S. mutans strains from participants with low salivary counts show high production of mutacins (63%). In contrast, participants with moderate and high salivary counts depict relatively low levels of mutacins (22 and 15%, respectively). Moreover, participants with low salivary counts showed high expression levels of genes encoding mutacins, a result that correlates with the strong antimicrobial activity of the group. Participants with moderate and high salivary counts however depict low expression levels of mutacin related genes, and little antimicrobial activity. No BLIS were detected in any of the groups studied. S. mutans isolated from the saliva of participants with low bacterial counts have significant antibacterial capacity compared to that of participants with moderate and high salivary counts. The superior lethality of S. mutans in participants with low salivary counts is likely due to the augmented expression of mutacin- related genes.
The principal aim of this work was to detect the bacteriocinogenic capacity of S. flexneri strain... more The principal aim of this work was to detect the bacteriocinogenic capacity of S. flexneri strains on members of the human intestinal flora. A total of 49 bacteriocinogenic S. flexneri strains were isolated from individuals of both sexes and different ages. The bacteriocins were detected by means of the drop method using E. coli and B. fragilis as target strains. The serotypes of the S. flexneri were determined. The producer capacity of bacteriocins was analysed in 10 different colonies of the same cellular clone and also the arbitrary units were determined. The highest number of bacteriocinogenic S. flexneri strains were obtained from diarrhoeal individuals from 0-10 years old and the S. flexneri serotype 2a was the most abundant. It was demonstrated that E. coli and B. fragilis isolated from the normal intestinal flora of healthy individuals were susceptible to the bacteriocinogenic S. flexneri strains. By means of the determination of arbitrary units per ml of the bacteriocin, it was demonstrated that colonies from a single colony isolate of a same clone of bacteriocinogenic S. flexneri produce different quantities of bacteriocin.
Uropathogenic E. coli 36692 cells synthesize fimbriae during the first half of the exponential gr... more Uropathogenic E. coli 36692 cells synthesize fimbriae during the first half of the exponential growth curve. The presence of the appendices was detected by electron microscopy and it was correlated with a high haemagglutination activity. Norfloxacin, amoxicillin and gentamicin supply 1/4 of their respective MICs, inhibiting the cell growth. Also all these drugs with the same sub MICs alter the haemagglutination titre and inhibit the fimbriation process of the uropathogenic E. coli. Gentamicin showed the highest inhibition of the haemagglutinating activity and fimbriae synthesis.
We isolated 2 Serratia marcescens strains, fim (0) and fim (-), from patients with urinary tract ... more We isolated 2 Serratia marcescens strains, fim (0) and fim (-), from patients with urinary tract infection. Adhesion properties were studied by hemagglutination, response of uroepithelial cells and electron microscopy techniques. S marcescens fim (+) showed high adherence to uroepithelial cells, hemagglutination capacity and peculiar electron microscopy characteristics. All of these are absent in the fim (-) variety. The fim (+) strain was resistant to nitrofurantoin, nalidixic acid, tetracyclin, ampicillin, gentamycin, cefradine, cephotaxime and cotrimoxazole, whereas the fim (-) strain was sensitive to all. An absence of extrachromosomal DNA was demonstrated in S marcescens fim (+) suggesting that its characteristics are not coded in plasmids.
Revista clínica de periodoncia, implantología y rehabilitación oral, Dec 1, 2017
Trabajo de invesTigación distribución gen fimA de Porphyromonas gingivalis en pacientes chilenos ... more Trabajo de invesTigación distribución gen fimA de Porphyromonas gingivalis en pacientes chilenos con periodontitis crónica
A strain of Shigella flexneri producing bacteriocin was isolated from a patient with diarrhea. Th... more A strain of Shigella flexneri producing bacteriocin was isolated from a patient with diarrhea. The main objective of this study was to isolate and partially characterize the bacteriocin. The producing microorganism was identified using biochemical, serological, and molecular methods. The lethal activity of the S. flexneri strain was studied using the drop method. This bacterial strain showed activity against different strains of E. coli and B. fragilis. Using immunological techniques, it was determined that S. flexneri belongs to serotype 2a, and by PCR, the presence of the ipaH plasmid was determined. By chromatographic techniques, it was determined that the bacteriocin is a peptide of high purity with a molecular weight of 66294.094 Da. The amino acid composition and sequence were determined by the Edman reaction, and a sequence of 619 amino acid residues was obtained. Only in five positions of this sequence, the amino acid glutamine changed to glutamic acid with respect to colici...
Currently, implant rehabilitation requires more than successful osseointegration, studies have de... more Currently, implant rehabilitation requires more than successful osseointegration, studies have described the need for a harmonious relationship between the levels of periimplant tissue and the already existing dentition to achieve an aesthetic and functional restoration. This can be accomplished with a careful balance of parameters such as the morphology and surface of the implant, the conditions of the receiving tissue, the surgical technique, the prosthesis design and the way in which the load is applied.1
Clinical implant dentistry and related research, Jan 15, 2018
In implant rehabilitation, a microspace is created at the abutment-implant interface (AII). Previ... more In implant rehabilitation, a microspace is created at the abutment-implant interface (AII). Previous research has shown that oral microbiome can proliferate in this microspace and affect periimplant tissues, causing inflammation in peri-implant tissues. Preventing microbial leakages through the AII is therefore an important goal in implantology. To determine the presence of marginal bacterial microleakage at the AII according to the torque applied to the prosthetic implant in vitro. Twenty-five Ticare Inhex internal conical implants (MG Mozo-Grau, Valladolid, España) were connected to a prosthetic abutment using torques of <10, 10, 20, 30, and 30 N and then sealed. The samples were submitted to cycles of occlusal loads and thermocycling, then one sample of each group was observed by micro TC, while the rest were mounted on devices according to the bacterial leakage model with Porphyromonas gingivalis. Bacterial leakage was observed only in the <10 and 10 N torque samples, and ...
The objective was to analyse the antibacterial ability of members of the intestinal microbiota of... more The objective was to analyse the antibacterial ability of members of the intestinal microbiota of Oncorhynchus mykiss specimens on several bacterial target strains that contaminate food and cause disease in humans. Bacterial colonies from an intestinal portion of the 20 specimens of O. mykiss were obtained in different culture media. Several of the colonies showed antibacterial action on different target strains. The bacterial species with the highest antagonistic capacity were Hafnia alvei and Lactococcus lactis and the more susceptible target strains were Aeromonas hydrophila, Listeria monocytogenes and Escherichia coli. Moreover, it was shown that all the antibacterial substances were susceptible to the action of various proteolytic enzymes. The detection of substances of a proteinaceous nature, possibly bacteriocins produced by bacteria of the intestinal microbiota of O. mykiss, allows further study of these products to establish biotechnological developments in the area of heal...
To detect S. mutans producers of mutacins and bacteriocins like substances (BLIS) from saliva of ... more To detect S. mutans producers of mutacins and bacteriocins like substances (BLIS) from saliva of participants with low, moderate, and high salivary counts. 123 strains of S. mutans were obtained from participants with low, moderate, and high salivary counts (age 18 and 20 years old) and their antibacterial capacity analyzed. By using PCR amplification, the expression levels of mutacins and BLIS genes were studied (expressed in arbitrary units/ml) in all three levels. S. mutans strains from participants with low salivary counts show high production of mutacins (63%). In contrast, participants with moderate and high salivary counts depict relatively low levels of mutacins (22 and 15%, respectively). Moreover, participants with low salivary counts showed high expression levels of genes encoding mutacins, a result that correlates with the strong antimicrobial activity of the group. Participants with moderate and high salivary counts however depict low expression levels of mutacin related genes, and little antimicrobial activity. No BLIS were detected in any of the groups studied. S. mutans isolated from the saliva of participants with low bacterial counts have significant antibacterial capacity compared to that of participants with moderate and high salivary counts. The superior lethality of S. mutans in participants with low salivary counts is likely due to the augmented expression of mutacin- related genes.
The principal aim of this work was to detect the bacteriocinogenic capacity of S. flexneri strain... more The principal aim of this work was to detect the bacteriocinogenic capacity of S. flexneri strains on members of the human intestinal flora. A total of 49 bacteriocinogenic S. flexneri strains were isolated from individuals of both sexes and different ages. The bacteriocins were detected by means of the drop method using E. coli and B. fragilis as target strains. The serotypes of the S. flexneri were determined. The producer capacity of bacteriocins was analysed in 10 different colonies of the same cellular clone and also the arbitrary units were determined. The highest number of bacteriocinogenic S. flexneri strains were obtained from diarrhoeal individuals from 0-10 years old and the S. flexneri serotype 2a was the most abundant. It was demonstrated that E. coli and B. fragilis isolated from the normal intestinal flora of healthy individuals were susceptible to the bacteriocinogenic S. flexneri strains. By means of the determination of arbitrary units per ml of the bacteriocin, it was demonstrated that colonies from a single colony isolate of a same clone of bacteriocinogenic S. flexneri produce different quantities of bacteriocin.
Uropathogenic E. coli 36692 cells synthesize fimbriae during the first half of the exponential gr... more Uropathogenic E. coli 36692 cells synthesize fimbriae during the first half of the exponential growth curve. The presence of the appendices was detected by electron microscopy and it was correlated with a high haemagglutination activity. Norfloxacin, amoxicillin and gentamicin supply 1/4 of their respective MICs, inhibiting the cell growth. Also all these drugs with the same sub MICs alter the haemagglutination titre and inhibit the fimbriation process of the uropathogenic E. coli. Gentamicin showed the highest inhibition of the haemagglutinating activity and fimbriae synthesis.
We isolated 2 Serratia marcescens strains, fim (0) and fim (-), from patients with urinary tract ... more We isolated 2 Serratia marcescens strains, fim (0) and fim (-), from patients with urinary tract infection. Adhesion properties were studied by hemagglutination, response of uroepithelial cells and electron microscopy techniques. S marcescens fim (+) showed high adherence to uroepithelial cells, hemagglutination capacity and peculiar electron microscopy characteristics. All of these are absent in the fim (-) variety. The fim (+) strain was resistant to nitrofurantoin, nalidixic acid, tetracyclin, ampicillin, gentamycin, cefradine, cephotaxime and cotrimoxazole, whereas the fim (-) strain was sensitive to all. An absence of extrachromosomal DNA was demonstrated in S marcescens fim (+) suggesting that its characteristics are not coded in plasmids.
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