RESUMEN
The presence of free-ranging urban birds is a risk factor for transmitting pathogens to captive animals and humans alike, including Salmonella spp. and diarrheagenic Escherichia coli. Cloacal swabs from 156 synanthropic Great egrets (Ardea alba) and feral pigeons (Columba livia domestica) that inhabit the surroundings of an urban zoo were processed for the identification of Salmonella spp. and diarrheagenic E. coli pathotypes. Bacterial species identification and genotypic characterization employed the matrix-assisted laser desorption ionization-time of flight mass spectrometry and PCR techniques, respectively, comparing their phylogenetic profiles through amplified fragment length polymorphism (AFLP) analysis. A total of 11 birds were positive for Salmonella Typhimurium (7%) and 9 individuals (5.8%) for diarrheagenic E. coli (enteropathogenic E. coli/Shiga-toxin producing E. coli [EPEC/STEC]) strains. S. Typhimurium strains presented highly similar AFLP profiles (85-100%), whereas EPEC/STEC strains showed more polymorphism. The results show free-ranging birds as carriers for both microorganisms in a zoo environment in Brazil for the first time and suggest these species as possible sources of infection to other animals as well as exposing personnel and visitors to potential zoonotic microorganisms. The presence of carriers highlights the importance of a surveillance system and the need for preventive measures to avoid attracting growing number of synanthropic avian species.
Asunto(s)
Aves/microbiología , Infecciones por Escherichia coli/veterinaria , Escherichia coli/aislamiento & purificación , Salmonelosis Animal/microbiología , Animales , Aves/clasificación , Brasil , Ciudades , Reservorios de Enfermedades , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Heces/microbiología , Humanos , Salmonelosis Animal/epidemiología , ZoonosisRESUMEN
Mycobacterium bovis Bacillus Calmette-Guerin (BCG) has been shown to down-regulate experimental allergic asthma, a finding that reinforced the hygiene hypothesis. We have previously found that recombinant BCG (rBCG) strain that express the genetically detoxified S1 subunit of pertussis toxin (rBCG-S1PT) exerts an adjuvant effect that enhances Th1 responses against BCG proteins. Here we investigated the effect of this rBCG-S1PT on the classical ovalbumin-induced mouse model of allergic lung disease. We found that rBCG-S1PT was more effective than wild-type BCG in preventing Th2-mediated allergic immune responses. The inhibition of allergic lung disease was not associated with increased concentration of suppressive cytokines or with an increased number of pulmonary regulatory T cells but was positively correlated with the increase in IFN-gamma-producing T cells and T-bet expression in the lung. In addition, an IL-12-dependent mechanism appeared to be important to the inhibition of lung allergic disease. The inhibition of allergic inflammation was found to be restricted to the lung because when allergen challenge was given by the intraperitoneal route, rBCG-S1PT administration failed to inhibit peritoneal allergic inflammation and type 2 cytokine production. Our work offers a nonclassical interpretation for the hygiene hypothesis indicating that attenuation of lung allergy by rBCG could be due to the enhancement of local lung Th1 immunity induced by rBCG-S1PT. Moreover, it highlights the possible use of rBCG strains as multipurpose immunomodulators by inducing specific immunity against microbial products while protecting against allergic asthma.
Asunto(s)
Hipersensibilidad/microbiología , Mycobacterium bovis/inmunología , Mycobacterium bovis/metabolismo , Células TH1/microbiología , Animales , Citocinas/metabolismo , Eosinófilos/microbiología , Femenino , Interferón gamma/metabolismo , Interleucina-12/genética , Interleucina-12/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Ovalbúmina/metabolismo , Proteínas Recombinantes/metabolismo , Células Th2/microbiologíaRESUMEN
The currently used pertussis vaccines are highly efficacious; however, neonates are susceptible to whooping cough up to the sixth month. In agreement, DTP-immunized neonate mice were not protected against intracerebral challenge with Bordetella pertussis. Neonate mice immunized with either DTP or a recombinant-BCG strain expressing the genetically detoxified S1 subunit of pertussis toxin do not show a humoral immune response against PT. On the other hand, rBCG-Pertussis induces higher PT-specific IFN-gamma production and an increase in both IFN-gamma(+) and TNF-alpha(+)-CD4(+)-T cells than the whole cell pertussis vaccine and confers protection against a lethal intracerebral challenge with B. pertussis.
Asunto(s)
Bordetella pertussis/inmunología , Mycobacterium bovis/genética , Toxina del Pertussis/inmunología , Vacuna contra la Tos Ferina/inmunología , Tos Ferina/prevención & control , Animales , Anticuerpos Antibacterianos/sangre , Bordetella pertussis/genética , Linfocitos T CD4-Positivos/inmunología , Vacuna contra Difteria, Tétanos y Tos Ferina/inmunología , Humanos , Recién Nacido , Interferón gamma/biosíntesis , Ratones , Toxina del Pertussis/genética , Vacuna contra la Tos Ferina/genética , Análisis de Supervivencia , Factor de Necrosis Tumoral alfa/biosíntesis , Tos Ferina/inmunologíaRESUMEN
The currently used pertussis vaccines are highly efficacious; however, neonates are susceptible to whooping cough up to the sixth month. In agreement, DTP-immunized neonate mice were not protected against intracerebral challenge with Bordetella pertussis. Neonate mice immunized with either DTP or a recombinant-BCG strain expressing the genetically detoxified S1 subunit of pertussis toxin do not show a humoral immune response against PT. On the other hand, rBCG-Pertussis induces higher PT-specific IFN-ã production and an increase in both IFN-ã+ and TNF-á+-CD4+-T cells than the whole cell pertussis vaccine and confers protection against a lethal intracerebral challenge with B. pertussis