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1.
Science ; 197(4300): 263-5, 1977 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-327545

RESUMEN

Streptococcus mutans and Vibrio cholerae, but not Escherichia coli, were killed by incubation with purified human apolactoferrin. Concentrations of lactoferrin below that necessary for total inhibition resulted in a marked reduction in viable colony-forming units. This bactericidal effect was contingent upon the metal-chelating properties of the lactoferrin molecule.


Asunto(s)
Escherichia coli/efectos de los fármacos , Lactoferrina/farmacología , Lactoglobulinas/farmacología , Streptococcus mutans/efectos de los fármacos , Streptococcus/efectos de los fármacos , Vibrio cholerae/efectos de los fármacos , Apoproteínas/farmacología , Quelantes/farmacología , Relación Dosis-Respuesta a Droga , Humanos , Hierro/metabolismo , Especificidad de la Especie
2.
J Immunol Methods ; 53(3): 335-43, 1982 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-6754816

RESUMEN

A rapid, quantitative solid-phase immunofluorescence assay has been developed to measure antibodies reactive with Streptococcus mutans in saliva and serum. Formalin killed bacteria were adsorbed to cellulose acetate discs and antibodies bound to the antigen-coated immunoabsorbent were detected by use of fluorescein-labeled antibody to human immunoglobulin isotypes. Quantitation was performed by placing the immunoabsorbent discs in a fluorometer. Low levels of naturally occurring antibodies reactive with S. mutans were easily detected in saliva and serum from normal human subjects.


Asunto(s)
Anticuerpos Antibacterianos/análisis , Fluoresceínas , Animales , Análisis Químico de la Sangre , Técnica del Anticuerpo Fluorescente , Técnicas de Inmunoadsorción , Conejos/inmunología , Saliva/análisis , Streptococcus mutans/inmunología
3.
Am J Infect Control ; 28(2): 123-9, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10760220

RESUMEN

BACKGROUND: Enterobacter cloacae has become a common cause of nosocomial infections. This study was designed to investigate the pattern of spread of E cloacae during an outbreak in a neonatal intensive care unit. METHODS: Enterobacterial repetitive intergenic consensus polymerase chain reaction was used to examine 111 E cloacae isolates from 17 patients, including 81 from surveillance cultures, 23 from endotracheal tubes, 3 from eyes, and 1 each from blood, urine, skin, and throat. Antibiotic susceptibility profiles were also obtained. RESULTS: Infection with E cloacae resulted from endogenous bacteria and from horizontal transmission. One group of 61 isolates, a third of which were obtained from clinical specimens, was uniformly susceptible to imipenem and ciprofloxacin only. A second group of 50 isolates, only 18% of which were obtained from clinical specimens, was susceptible to all antibiotics tested except for aminopenicillins and first-generation cephalosporins. CONCLUSION: These data indicate that (1) patient-to-patient spread is an important cause of E cloacae infection in the neonatal intensive care unit and (2) highly antibiotic-resistant E cloacae may emerge during an outbreak.


Asunto(s)
Infección Hospitalaria/microbiología , Infección Hospitalaria/transmisión , ADN Bacteriano/genética , Brotes de Enfermedades/estadística & datos numéricos , Transmisión de Enfermedad Infecciosa/estadística & datos numéricos , Enterobacter cloacae/clasificación , Enterobacter cloacae/genética , Infecciones por Enterobacteriaceae/microbiología , Infecciones por Enterobacteriaceae/transmisión , Control de Infecciones/métodos , Unidades de Cuidado Intensivo Neonatal , Reacción en Cadena de la Polimerasa/métodos , Centros Médicos Académicos , Análisis por Conglomerados , Secuencia de Consenso , Dermatoglifia del ADN , District of Columbia , Farmacorresistencia Microbiana , Variación Genética , Humanos , Recién Nacido , Pruebas de Sensibilidad Microbiana , Prevalencia , Serotipificación
4.
Am J Infect Control ; 26(6): 563-8, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9836839

RESUMEN

BACKGROUND: Enterococci have become important nosocomial pathogens and now account for approximately 12% of nosocomial infections. Enterococci can be transferred from patient to patient and from health care personnel to patient. We investigated the clonal diversity of vancomycinresistant enterococci (VRE) causing an outbreak of infections and attempted to determine the patterns of spread of these bacteria in a university hospital. METHODS: Ribotyping was used to examine the clonal diversity of 50 VRE isolates, including 23 from wounds, 14 from urine, 8 from blood, 3 from the rectum, 1 from drainage, and 1 from the cornea. RESULTS: Nine patients were infected with Enterococcus faecalis, 10 with Enterococcus faecium, 3 with both E faecalis and E faecium, and 1 with Enterococcus avium. The results suggest that the sources of the VRE infections included endogenous strains and strains acquired by transmission from attending staff or from the environment. Three patients were infected by both nosocomial and endogenous strains. CONCLUSIONS: These data suggest that the collection and analysis of several isolates from repeated specimens is necessary to obtain a fuller understanding of the epidemiology and population structure of antibiotic-resistant enterococci.


Asunto(s)
Antibacterianos , Infección Hospitalaria/microbiología , ADN Bacteriano/análisis , Brotes de Enfermedades/estadística & datos numéricos , Enterococcus faecalis/clasificación , Enterococcus faecium/clasificación , Infecciones por Bacterias Grampositivas/microbiología , Vancomicina , Células Clonales , Análisis por Conglomerados , Infección Hospitalaria/transmisión , District of Columbia , Farmacorresistencia Microbiana , Enterococcus faecalis/genética , Enterococcus faecium/genética , Infecciones por Bacterias Grampositivas/transmisión , Hospitales Universitarios , Humanos , Control de Infecciones , Filogenia , Factores de Riesgo , Serotipificación
5.
Ann N Y Acad Sci ; 409: 1-21, 1983 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-6191608

RESUMEN

Mucosal defense is provided by a number of host factors countering the specific virulence factors of the many microorganisms infecting the mucous membranes. Secretory IgA antibodies presumably play an important role. Increase of the sIgA antibodies may most advantageously be attained by parenteral immunization, following mucosal priming. This was demonstrated in a rat model, where it was also noted that antigen injection into PP induced high milk IgA antibody levels. In man, parenteral vaccination against polio increased the sIgA antibody levels in the milk of mothers previously exposed naturally to the poliovirus. The response was relatively short-lived. In the previously unexposed, there was little or no response. By contrast peroral immunization with live poliovirus vaccine did not increase, or even decrease, the milk sIgA poliovirus antibody levels. Although salivary sIgA antibodies against antigens of colonizing E. coli appear during the first days of life, they are slow to increase. This deficiency is richly compensated for by all the sIgA antibodies that are provided the baby through the milk. No transfer of dimeric IgA into the milk could be shown in lactating rats, in contrast to what has been reported in mice. There is no evidence for a contribution to milk sIgA from serum in man. Close to parturition, human milk often contains some 7S IgA and various sizes of free SC, in addition to the dominating 11S sIgA. A few days later there is almost exclusively monomeric SC and 11S sIgA. IgG antibodies also play a role at the mucosal level. IgG2 antibodies against the bacterial polysaccharide capsule are as slow to appear as sIgA in ontogeny, possibly explaining the prevalence of infections with encapsulated bacteria and the poor response to polysaccharide vaccines in early childhood. Other defense factors preventing infections by way of mucous membranes may be important. Thus, oligosaccharides present in human milk seem to specifically prevent pneumococcal attachment to retropharyngeal cells. This anti-attachment capacity, in addition to that provided by milk and salivary IgA antibodies, may explain why breast-fed babies have less otitis media than formula-fed ones.


Asunto(s)
Antígenos de Superficie , Inmunoglobulina A/biosíntesis , Mucosa Intestinal/inmunología , Secreciones Intestinales/inmunología , Adulto , Animales , Anticuerpos Antibacterianos/biosíntesis , Células Productoras de Anticuerpos/inmunología , Antígenos/inmunología , Antígenos Bacterianos/inmunología , Niño , Femenino , Humanos , Inmunización , Inmunoglobulina A Secretora/análisis , Inmunoglobulina A Secretora/biosíntesis , Inmunoglobulina G/biosíntesis , Inmunoglobulina M/biosíntesis , Recién Nacido , Ratones , Leche Humana/inmunología , Antígenos O , Embarazo , Ratas
6.
FEMS Microbiol Lett ; 126(2): 177-80, 1995 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-7705609

RESUMEN

The virulence of Candida albicans strain SC5413 and two isogenic derivatives have been investigated in a rat model of oropharyngeal candidiasis. The results demonstrate that both mutant strains are avirulent in this animal model while the parental strain readily initiates infection. Avirulence is not related to altered growth characteristics or the inability of the strains to undergo yeast-to-hyphal morphogenesis. The potential importance of nutritional sufficiency as a virulence factor as well as the possibility of utilizing such strains in the development of an in vitro expression technology system for Candida albicans is discussed.


Asunto(s)
Candida albicans/genética , Candidiasis Bucal/microbiología , Animales , Candida albicans/patogenicidad , Modelos Animales de Enfermedad , Mutación , Ratas , Ratas Sprague-Dawley , Virulencia
7.
J Med Microbiol ; 42(1): 67-72, 1995 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7739028

RESUMEN

Three hundred and sixty-seven strains of pioneer streptococci isolated from the mouths of 40 healthy, full-term infants during the first month of life were examined by two taxonomic schemes that incorporated biochemical and physiological characteristics, IgA1 protease production and glycosidase activities. Streptococcus mitis biovar 1 and S. oralis comprised 55.0% of the pioneer streptococci isolated from neonates. S. salivarius constituted 25.3% of the isolates, while S. anginosus, S. mitis biovar 2, S. sanguis and S. gordonii accounted collectively for 11.4%. Difficulties in identifying streptococci were encountered and 8.4% of the 367 isolates could not be assigned to a recognised species.


Asunto(s)
Boca/microbiología , Streptococcus/aislamiento & purificación , Proteínas Bacterianas/análisis , Técnicas de Tipificación Bacteriana , Análisis por Conglomerados , Humanos , Recién Nacido , Estudios Longitudinales , Streptococcus/clasificación , Streptococcus sanguis/clasificación , Streptococcus sanguis/aislamiento & purificación
8.
J Dent Res ; 54(3): 449-57, 1975.
Artículo en Inglés | MEDLINE | ID: mdl-806617

RESUMEN

The incorporation of 1 or 3% sodium phytate in confectioners sugar produced minimal changes in the physical,chemical, and microbial composition of dental plaque in tube-fed monkeys during a two-week period. Only a reduction in yeasts and lactobacilli could be ascribed to the presence of phytate. Other changes were attributable to the transition from conventional feeding to tube-feeding, irrespective of the presence of absence of phytate.


Asunto(s)
Placa Dental/metabolismo , Inositol/análogos & derivados , Ácido Fítico , Animales , Calcio/sangre , Calcio/metabolismo , Metabolismo de los Hidratos de Carbono , Carbohidratos/administración & dosificación , Placa Dental/microbiología , Dieta Cariógena , Femenino , Lactobacillus/efectos de los fármacos , Macaca fascicularis , Magnesio/sangre , Magnesio/metabolismo , Masculino , Neisseria/efectos de los fármacos , Nitrógeno/metabolismo , Nutrición Parenteral Total , Fósforo/metabolismo , Ácido Fítico/farmacología , Streptococcus/efectos de los fármacos , Levaduras/efectos de los fármacos , Zinc/sangre
9.
J Dent Res ; 56(3): 198-204, 1977 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-265950

RESUMEN

This study was undertaken in order to correlate the immune status of persons with various types of immune dysfunctions with the incidence of dental caries. Preliminary data on caries experience and the microbial composition of plaque in these individuals are presented. The findings suggest that persons with immunoglobulin dysfunctions have a greater susceptibility to dental caries and have a greater frequency of harboring S mutans than do normal persons.


Asunto(s)
Caries Dental/complicaciones , Síndromes de Inmunodeficiencia/complicaciones , Adolescente , Adulto , Agammaglobulinemia/complicaciones , Bacterias/citología , Niño , Preescolar , Susceptibilidad a Caries Dentarias , Placa Dental/microbiología , Disgammaglobulinemia/complicaciones , Humanos , Inmunoglobulina A , Saliva/inmunología
10.
Arch Oral Biol ; 44(10): 871-83, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10530920

RESUMEN

The characteristics of the mucosal immune response to Streptococcus mutans cells, antigen A, antigen B, glucosyltransferases and glucan-binding proteins were examined in four pregnant chimpanzees that had been immunized perorally with Strep. mutans. Six pregnant chimpanzees served as non-immunized controls. None of the chimpanzees harbored S. mutans. Samples of milk were collected from all animals throughout the experiment. Peroral immunization resulted in an overall 17-fold median increase in SIgA in milk. Although SIgA1 comprised almost two-thirds of milk SIgA, Strep. mutans whole-cell antibody activity was contained predominantly in the SIgA2 subclass. The difference between the specific activities of anti-Strep. mutans SIgA1 and SIgA2 antibodies compared over time reached the borderline of statistical significance (p = 0.08). The avidity of anti-Strep. mutans antibodies was low in three of four chimpanzees and there was no evidence of affinity maturation. SIgA antibodies from the milk of all four immunized chimpanzees recognized antigen A. In three animals these antibodies were restricted to the SIgA1 subclass and, in one animal, anti-A antibodies were confined to SIgA2. Antibodies from all of the immunized chimpanzees recognized degradation products of antigen B in both the SIgA1 and the SIgA2 subclasses. Only two of four immunized chimpanzees responded to glucosyltransferases and these antibodies were restricted to the SIgA1 subclass. None of the chimpanzees responded to the 74-kDa glucan-binding protein. However, three animals produced SIgA1 antibodies against the 59-kDa glucan-binding protein and two of these also produced SIgA2 antibodies against this protein.


Asunto(s)
Antígenos Bacterianos/inmunología , Inmunización/métodos , Leche/inmunología , Pan troglodytes/inmunología , Streptococcus mutans/inmunología , Análisis de Varianza , Animales , Afinidad de Anticuerpos , Antígenos Bacterianos/aislamiento & purificación , Western Blotting/estadística & datos numéricos , Electroforesis en Gel Bidimensional/estadística & datos numéricos , Femenino , Inmunidad Mucosa , Inmunización/estadística & datos numéricos , Inmunoglobulina A Secretora/análisis , Embarazo
11.
Adv Exp Med Biol ; 107: 281-92, 1978.
Artículo en Inglés | MEDLINE | ID: mdl-105569

RESUMEN

The present studies assayed antibody activities in serum and saliva of animals immunized by different routes, with cells of S. mutans or cell-free preparations containing GTF, FTF, LTA and/or dextranase synthesized by S. mutans. The results show that the type of immunogenic preparation and the route of its administration can elicit different antibody response and may in part explain the disparity of results achieved by different investigators. The results further emphasize the need to use standardized preparations and carefully described protocols for vaccination.


Asunto(s)
Anticuerpos Antibacterianos/biosíntesis , Antígenos Bacterianos , Hexosiltransferasas/inmunología , Streptococcus mutans/inmunología , Animales , Reacciones Antígeno-Anticuerpo , Caries Dental/inmunología , Dextranasa/antagonistas & inhibidores , Glucosiltransferasas/antagonistas & inhibidores , Glucosiltransferasas/inmunología , Haplorrinos , Hexosiltransferasas/antagonistas & inhibidores , Conejos , Saliva/inmunología , Streptococcus mutans/enzimología , Streptococcus mutans/patogenicidad
12.
J Am Dent Assoc ; 100(5): 677-81, 1980 May.
Artículo en Inglés | MEDLINE | ID: mdl-6767768

RESUMEN

By feeding rats their essential nutrition through gastric intubation and test foods on a programmed feeder it is possible to determine the cariogenicity of many foods in animals. Because the test food is the only substance that contacts teeth, all carious lesions that develop can be ascribed solely to the ingestion of the test food. Caries scores can be expressed as ratios of those occurring when animals are fed pure sucrose, thereby comparisons can be made from one experiment to another. The number of carious lesions that develop is directly related to the frequency of ingestion of sucrose. In addition, frequency of ingestion of sucrose has a significant effect on the establishment of S mutans in the mouths of animals. We believe that the approach used here can establish differences in the cariogenic potential of foods in a simple, unequivocal, and reproducible manner.


Asunto(s)
Cariogénicos , Alimentos , Animales , Cacao , Dulces , Caries Dental/microbiología , Grano Comestible , Nutrición Enteral , Intubación Gastrointestinal , Ratas , Almidón/farmacología , Streptococcus mutans/fisiología , Sacarosa/farmacología
18.
Artículo en Inglés | MEDLINE | ID: mdl-19022761

RESUMEN

The process by which a single fertilized egg develops into a human being with more than 200 cell types--each with a distinct gene expression pattern controlling its cellular state--is poorly understood. Knowledge of the transcriptional regulatory circuitry that establishes and maintains gene expression programs in mammalian cells is fundamental to understanding development and should provide the foundation for improved diagnosis and treatment of disease. Although it is not yet feasible to map the entirety of this circuitry in vertebrate cells, recent work in embryonic stem (ES) cells has demonstrated that core features of the circuitry can be discovered through studies involving selected regulators. Here, we highlight the fundamental insights that have emerged from studies that examined the role of transcription factors, chromatin regulators, signaling pathways, and noncoding RNAs in the regulatory circuitry of ES cells. Maps of regulatory circuitry and the insights that have emerged from these studies have improved our understanding of global gene expression and are facilitating efforts to reprogram cells for disease therapeutics and regenerative medicine.


Asunto(s)
Células Madre Embrionarias/fisiología , Transcripción Genética , Animales , Diferenciación Celular/genética , Diferenciación Celular/fisiología , Regulación del Desarrollo de la Expresión Génica , Redes Reguladoras de Genes , Humanos , Modelos Genéticos , Proteínas del Grupo Polycomb , ARN no Traducido/genética , Proteínas Represoras/genética , Proteínas Represoras/fisiología , Transducción de Señal , Factores de Transcripción/genética , Factores de Transcripción/fisiología
19.
Microb Pathog ; 11(1): 39-46, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1795627

RESUMEN

Immunoglobulin (Ig)A proteases synthesized by human mucosal pathogens have a unique specificity for human IgA and will not cleave IgA from other species. In contrast, animal pathogens have not reliably been shown to cleave IgA of the animals they infect. This lack of an animal model has prevented an understanding of the importance of IgA1 proteases as virulence factors. One strategy to develop an animal model would be to identify a species capable of infection by a human IgA-producing pathogen whose IgA was susceptible to cleavage by IgA1 protease of that bacterium. The chimpanzee can be infected with Haemophilus influenzae and is closely related immunologically to man. For these reasons it was sought to determine whether chimpanzee secretory IgA (SIgA) is susceptible to cleavage by IgA1 protease of H. influenzae. This report shows that chimpanzee SIgA can indeed be cleaved at the hinge region by H. influenzae IgA1 protease into Fab alpha and (Fc alpha)2.SC fragments. The susceptibility of chimpanzee SIgA to IgA1 protease of a human pathogen could serve as the basis of an animal model to determine the importance of IgA1 protease in pathogenesis.


Asunto(s)
Haemophilus influenzae/enzimología , Inmunoglobulina A Secretora/metabolismo , Péptido Hidrolasas/metabolismo , Serina Endopeptidasas , Animales , Western Blotting , Cromatografía de Afinidad , Electroforesis en Gel de Poliacrilamida , Femenino , Haemophilus influenzae/patogenicidad , Fragmentos Fab de Inmunoglobulinas/metabolismo , Fragmentos Fc de Inmunoglobulinas/metabolismo , Pan troglodytes , Virulencia
20.
Infect Immun ; 50(2): 398-402, 1985 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-4055024

RESUMEN

The structural integrity of immunoglobulin A (IgA), IgG, and IgM and lactoferrin in dental plaque fluid samples from two populations of Colombian children with contrasting levels of dental caries was examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by electrophoretic transfer to nitrocellulose. The immune factors or their fragments or both were detected with monospecific antibody conjugated with horseradish peroxidase. All the immune factors examined were extensively degraded, although there appeared to be small amounts of intact IgA and IgG in some samples. Analysis of the samples with antibody to secretory component showed that secretory IgA as well as serum IgA was degraded. IgG appeared to be cleaved into two major fragments, one fragment having a relative mobility similar to the F(ab')2 fragment of IgG and the other a relative mobility slightly greater than Fc. IgM and lactoferrin were virtually completely degraded. There was no apparent relationship between the fragmentation patterns of IgA and IgG in the plaque fluid samples from the two communities and their susceptibility to dental caries.


Asunto(s)
Placa Dental/inmunología , Inmunoglobulinas/análisis , Lactoferrina/análisis , Lactoglobulinas/análisis , Electroforesis en Gel de Poliacrilamida , Humanos , Inmunoglobulina A/análisis , Fragmentos Fc de Inmunoglobulinas/análisis , Inmunoglobulina G/análisis , Inmunoglobulina M/análisis , Peso Molecular
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