Effect of carbohydrates on the adhesion of Bordetella bronchiseptica to the respiratory epithelium in rabbits.

This study proposes an ecological approach for preventing respiratory tract infections caused by Bordetella bronchiseptica in mammals using a mixture of carbohydrates. In an in vivo study, 51-day-old New Zealand rabbits were treated with a solution containing 1 × 107 CFUs of B. bronchiseptica and 250 µg of one of the following carbohydrates: N acetylglucosamine (GlcNAc), N acetylgalactosamine (GalNAc), alpha methyl mannose (AmeMan), alpha methyl glucose (AmeGlc) and sialic acid (Neu5AC). Positive (B. bronchiseptica) and negative (Physiological Saline Solution (PSS)) controls were included. Animals treated with GlcNAc or AmeGlc showed no clinical signs of infection and exhibited a significant reduction (p < 0.05) in the severity of microscopic lesions evaluated in the nasal cavity and lung compared with the positive controls. Additionally, the presence of bacteria was not detected through microbiological isolation or PCR in the lungs of animals treated with these sugars. Use of a mixture of GlcNAc and AmeGlc resulted in greater inhibition of microscopic lesions, with a significant reduction (p < 0.05) in the severity of these lesions compared to the results obtained using individual sugars. Furthermore, the bacterium was not detected through microbiological isolation, Polymerase Chain Reaction (PCR) or indirect immunoperoxidase (IIP) in this group.

Intranasal instillation of Pasteurella multocida lipopolysaccharide in rabbits causes interstitial lung damage.

In order to characterize the in vivo lesions in the nasal cavities and lungs, twenty-eight rabbits were intranasally instilled with lipopolysaccharide (LPS) from P. multocida and then divided into seven groups according to euthanasia time. The nasal cavities and the lungs were processed for light microscopy, lectin histochemistry and transmission electron microscopy. Increased goblet cell activation and neutrophil infiltration were relevant changes in the nasal cavity. A predominantly interstitial pattern of diffuse alveolar damage and bronchopneumonic foci were the main lesions found in the lungs. LPS was found in the cytoplasm of ciliated cells, goblet cells, glandular cells, venular endothelial cells and neutrophils in the nasal cavity and in club cells, capillary endothelial cells and neutrophil in the lung. This study demonstrates that the LPS is able to cause lesions in the upper and lower respiratory tract, it binds to and is internalized by respiratory epithelial cells. Furthermore, it also traverses the intercellular spaces to reach the blood vessels, where it binds to and is internalized by neutrophil and red blood cells. These cells may then travel to the lungs where the LPS induces typical diffuse alveolar damage. This route of lung interstitial damage, to our knowledge, has not been described for this molecule or any known pathogen.

The effect of carbohydrates on the adherence of Pasteurella multocida to the nasal respiratory epithelium.

Pasteurella multocida subsp. multocida is responsible for different diseases that generate great economic losses in farm animal. The effectiveness of immunization against those bacteria are variable and the use of antibiotics is questioned; for that reason, we investigated the potential inhibitory effect of different carbohydrates on the adherence in vivo of P. multocida to the rabbit respiratory epithelium as an alternative for the prevention of respiratory infections. Rabbits were intranasally and intratracheally inoculated with a solution containing 200 µl of 1x107 CFU of P. multocida that was previously mixed with 250 µg /200 µl of N-acetylglucosamine, alphamethylglucoside, alphamethylmannoside, N-acetylgalactosamine or sialic acid. The animals that received N-acetylglucosamine, alphamethylglucoside or alphamethylmannoside individually or a mixture of these three carbohydrates plus the bacterium, showed a significant decrease (P <0.05) of the clinical symptoms, microscopic and macroscopic lesions in the nasal septa and in the lungs; also, the number of adhered bacteria to the nasal epithelium were also significantly reduced. This research demonstrates for the first time that such an approach could convert into a method for prevention of P. multocida infection in rabbits that is ecologically and economically safe and effective.

Biological traits of the predatory mirid Macrolophus praeclarus, a candidate biocontrol agent for the Neotropical region.

The predatory mirid Macrolophus praeclarus is widely distributed throughout the Americas, and is reported to prey upon several horticultural pest species. However, little is known about its biology, thermal requirements, crop odour preferences, phytophagy, and capability to induce defensive responses in plants. When five temperatures studied (20, 25, 30, 33 and 35°C) were tested and Ephestia kuehniella was used as prey, the developmental time from egg to adult on tomato, was longest at 20°C (56.3 d) and shortest at 33°C (22.7 d). The ability of nymphs to develop to adults decreased as the temperature increased, with the highest number of nymphs reaching the adult stage at 20°C (78.0%) and lowest at 35°C (0%). The lower and upper developmental thresholds were estimated at 11.2° and 35.3°C, respectively. The maximum developmental rate occurred at 31.7°C and the thermal constant was 454.0 ± 8.1 degree days. The highest predation rate of E. kuehniella eggs was obtained at 30°C. In Y-tube olfactory choice tests, M. praeclarus selected tomato, sweet pepper and eggplant odours more frequently than no plant control treatment. Macrolophus praeclarus feeding did not damage tomato plants compared to another zoophytophagous mirid, Nesidiocoris tenuis, which caused necrotic rings. The phytophagy of M. praeclarus induced defensive responses in tomato plants through the upregulation of the jasmonic acid metabolic pathway. The implications of the findings for using M. praeclarus in tomato biological control programmes in the Americas are discussed.

Assessment of Pasteurella multocida A Lipopolysaccharide, as an Adhesin in an In Vitro Model of Rabbit Respiratory Epithelium.

The role of the P. multocida lipopolysaccharide (LPS) as a putative adhesin during the early stages of infection with this bacterium in the respiratory epithelium of rabbits was investigated. By light microscopy and double enzyme labeling of nasal septa tissues, the amount of bacteria attached to the respiratory epithelium and the amount of LPS present in goblet cells at different experimental times were estimated. Transmission electron microscopy (TEM) and LPS labeling with colloidal gold particles were also used to determine the exact location of LPS in the cells. Septa that were challenged with LPS of P. multocida and 30 minutes later with P. multocida showed more adherent bacteria and more severe lesions than the other treatments. Free LPS was observed in the lumen of the nasal septum, forming bilamellar structures and adhering to the cilia, microvilli, cytoplasmic membrane, and cytoplasm of epithelial ciliated and goblet cells. The above findings suggest that P. multocida LPS plays an important role in the process of bacterial adhesion and that it has the ability of being internalized into host cells.

Un acercamiento al "Pénfigo"desde la odontología / An approach to "Pemphigus" from dentistry

La aproximación a las lesiones de tipo pénfigo que se presentan en cavidad oral parte de su apariencia clínica, manifestación sistémica, criterio diagnóstico y fisiopatología. Éste se describe, como una ampolla producida por la separación entre las uniones desmosomales debido a la presencia de autoanticuerpos en contra de las proteínas de adhesión, las desmogleinas. Su diagnóstico diferencial es el penfigoide y la etiología es de carácter hereditario o por causa externas como: radiación ultravioleta, dieta, pesticidas, medicamentos, entre otros. Su presentación característica es una ampolla con líquido seroso la cual se manifiesta en sitios como mucosas y piel. Se clasifica en 3 variedades principales, el vulgar, el foliáceo y el paraneoplásico. Su diagnóstico se da por apariencia clínica y con análisis de laboratorio (biopsia, entre otros). Para su tratamiento el uso de corticosteroides tópicos y sistémicos es el usual, iniciando con altas dosis y posteriormente con bajas en etapas de mantenimiento. Muchos de ellos ceden al tratamiento pero otros pueden generar complicaciones graves lo que depende de la respuesta inmune del paciente.

The approximation to Pemphigus-like lesions that occur in the oral cavity are based on clinical appearance, systemic manifestations, diagnostic criteria, and pathophysiology. This is described as a blister caused by the separation between the desmosomal junctions due to the presence of autoantibodies against adhesion proteins, the desmogleins. Differential diagnosis is pemphigoid and etiology of hereditary or external causes such as ultraviolet radiation, diet, pesticides, drugs, among others. The characteristic presentation feature is a blister with serous fluid which manifests as mucosal sites and skin. It is classified into three main varieties, the vulgar, the foliaceus and paraneoplastic. Its diagnosis is given by clinical appearance and laboratory tests (biopsy, etc.). Treatment includes the use of topical and systemic corticosteroids, starting with high doses and subsequently with low maintenance stages. Many improve with treatment, but some may lead to serious complications, which depending on the patient's immune response.

Ultrastructural Comparison of the Nasal Epithelia of Healthy and Naturally Affected Rabbits with Pasteurella multocida A.

An ultrastructural comparison between the nasal cavities of healthy rabbits and those suffering from two forms of spontaneous infection with Pasteurella multocida was undertaken. Twelve commercially produced rabbits of different ages and respiratory health status were divided into four groups: healthy from 0 to 21 days (G1, n = 2); healthy from 23 to 49 days (G2, n = 2); healthy from 51 to 69 days (G3, n = 2); diseased rabbits with septicemia and the rhinitic form of P. multocida infection (G4, n = 3). The main ultrastructural changes observed were a widening of the interepithelial spaces, increased activity and number of goblet cells, the formation of two types of vacuoles in epithelial cells, the degranulation and migration of heterophils between the epithelial cells, and the association of this migration with some of the other changes. No bacteria were observed adhering to the epithelium, and very few were observed free in the mucus. Scant inter-epithelial spaces were found in healthy rabbits, but they were not as large and numerous as those found in diseased animals. We discuss the origin and meaning of these changes but, we focus on the significance of the inter-epithelial spaces and goblet cells for the defense of the upper respiratory airways against the bacterium and its lipopolysaccharide.

Interaction of Bordetella bronchiseptica and Its Lipopolysaccharide with In Vitro Culture of Respiratory Nasal Epithelium.

The nasal septa of fetal rabbits at 26 days of gestation were harvested by cesarean section of the does while under anesthesia and then exposed to Bordetella bronchiseptica or its lipopolysaccharide (LPS) for periods of 2 and 4 hours. A total of 240 explants were used. The tissues were examined using the Hematoxylin & Eosin technique. Then, semithin sections (0.5 µm) were stained with toluidine blue and examined with indirect immunoperoxidase (IPI) and lectin histochemistry. The most frequent and statistically significant findings were as follows: (1) cell death and increased goblet cell activity when exposed to bacteria and (2) cell death, cytoplasmic vacuolation and infiltration of polymorphonuclear leukocytes when exposed to LPS. The lesions induced by the bacterium were more severe than with LPS alone, except for the cytoplasmic vacuolation in epithelial cells. IPI stained the ciliated border of the epithelium with the bacterium more intensely, while LPS lectin histochemistry preferentially labeled the cytoplasm of goblet cell. These data indicate that B. bronchiseptica and its LPS may have an affinity for specific glycoproteins that would act as adhesion receptors in both locations.

Toll-like receptors participate in macrophage activation and intracellular control of Leishmania (Viannia) panamensis.

Toll-like receptors (TLRs) play a central role in macrophage activation and control of parasitic infections. Their contribution to the outcome of Leishmania infection is just beginning to be deciphered. We examined the interaction of Leishmania panamensis with TLRs in the activation of host macrophages. L. panamensis infection resulted in upregulation of TLR1, TLR2, TLR3, and TLR4 expression and induced tumor necrosis factor alpha (TNF-α) secretion by human primary macrophages at comparable levels and kinetics to those of specific TLR ligands. The TLR dependence of the host cell response was substantiated by the absence of TNF-α production in MyD88/TRIF(-/-) murine bone marrow-derived macrophages and mouse macrophage cell lines in response to promastigotes and amastigotes. Systematic screening of TLR-deficient macrophages revealed that TNF-α production was completely abrogated in TLR4(-/-) macrophages, consistent with the increased intracellular parasite survival at early time points of infection. TNF-α secretion was significantly reduced in macrophages lacking endosomal TLRs but was unaltered by a lack of TLR2 or MD-2. Together, these findings support the participation of TLR4 and endosomal TLRs in the activation of host macrophages by L. panamensis and in the early control of infection.

Ulcerativas Necrotizantes / Necrotizing Ulceratives

Las lesiones ulcerativas necrotizantes han sido documentadas a través de la historia. Su denominación, diagnóstico y tratamiento ha evolucionado con el paso de los años, hasta el presente, partiendo en Gingivitis Ulcerativa Necrotizante (GUN) caracterizada como una lesión de rápida evolución, de dolor paroxístico, confinada al margen gingival y papilar. La Periodontitis Ulcerativa Necrotizante (PUN), es ampliamente considerada como una evolución de GUN, involucrando al tejido óseo y a las estructuras de inserción, la falta de medidas terapéuticas ante estas entidades, generará la evolución a Estomatitis Ulcerativa Necrotizante (EUN), la cual involucra estructuras diferentes a los tejidos dentales y de soporte, como las mucosas circundantes. Dichas entidades exhiben signos patognomónicos comunes como sangrado, ulceración, necrosis papilar, supuración, dolor y mal olor, con predominio de microflora específica: fusobacterias y espiroquetas asociadasa factores predisponentes como stress, cigarrillo, desnutrición y alcohol. En la actualidad, la más fuerte asociación epidemiológica es con el Virus de inmunodeficiencia humana (VIH), en pacientes que presentan estados de inmunosupresión menores a 200.000 linfocitos T CD4, por tal motivolos portadores de cualquiera de estos tipos de lesión deben orientar al clínico la necesidad de confirmar el diagnóstico presuntivo de seropositividad. Los parámetros de tratamiento están encausados a la erradicación del agente etiológico, empleando medios mecánicos, como detartraje y alisado radicular apoyado en empleo de antimicrobianos locales y sistémicos, y el control de los factores de riesgo.

Necrotizing ulcerative lesions have been documented throughout history. Your name, diagnosis and treatment has evolved over the years, to date, starting in Necrotizing Ulcerative Gingivitis (NUG) characterized as a rapidly developing lesion, paroxysmal pain, confined to the gingival margin and papillary. Necrotizing Ulcerative Periodontitis (NUP) is widely regarded as an evolution of NUG, involving the bone and the insertion structures, lack of therapeutic measures against these entities generate evolution, Necrotizing Ulcerative Stomatitis (EUN), which involves different structures to the dental tissues and support, as the surrounding mucosa. Such entities exhibit common pathognomonic signs such as bleeding, ulceration, papillary necrosis, suppuration, pain and bad smell, with a predominance of specific microflora: Fusobacteria and spirochetes associated with predisposing factors such as stress, smoking, malnutrition and alcohol. Currently, the strongest epidemiological association is with the human immunodeficiency virus (HIV) in patients with immunosuppressive states below 200.000 CD4 T cells, as such carriers of either type of injury should guide the clinician to confirm the presumptive diagnosis of HIV infection. The treatment parameters are prosecuted to the eradication of the causative agent using mechanical means such as scaling and root planning supported employment for local and systemic antimicrobials, and control of risk factors.

Risk factors for pulmonary Aspergillus terreus infection in patients with positive culture for filamentous fungi.

BACKGROUND: Invasive aspergillosis (IA) is a common fungal infection in immunocompromised patients and has a high mortality rate. Among patients with IA, Aspergillus terreus infections have become a growing concern in the past few years. OBJECTIVE: To determine the clinical risk factors for isolation of and respiratory infection by A terreus in patients with culture findings positive for filamentous fungi. METHODS: Cohort study of 505 consecutive isolates of filamentous fungi in 332 patients from one center. A terreus was present in 46 isolates from 40 patients (9.1%). Clinical histories were reviewed to identify the risk factors related to isolation of and infection by A terreus, which were grouped into three categories (ie, host factors, factors related to immunosuppression, and factors related to hospitalization), and were analyzed using a multiple logistic regression model. RESULTS: A total of 192 of 505 isolates studied (38%) were due to invasive respiratory infection. A total of 27 of 46 cultures (58.7%) that were positive for A terreus were due to invasive infection (odds ratio [OR], 2.53; 95% confidence interval [CI], 1.37 to 4.69; p = 0.034). The factors associated with invasive A terreus infection were prophylactic use of amphotericin B aerosols (OR, 27.8; 95% CI, 6.7 to 109.7; p = 0.001) and mechanical ventilation (OR, 3.3; 95% CI, 1.02 to 10.9; p = 0.04). Transplantation was associated with a lower risk of A terreus infection (OR, 0.2; 95% CI, 0.046 to 0.789; p = 0.02). CONCLUSIONS: In patients with culture findings positive for filamentous fungi, the prophylactic use of amphotericin B aerosols and mechanical ventilation are associated with a higher risk of A terreus infections. In these patients, transplantation is associated with a lower risk of isolation and respiratory infection by A terreus.

Direct genotyping of animal and human isolates of Toxoplasma gondii from Colombia (South America).

Genetic analysis of the SAG2 locus was performed to determine the prevalence of the main genotypes of Toxoplasma gondii (SAG2 types I, II, and III) associated with humans, cats, birds and guinea pig toxoplasmosis in Colombia. This typing was directly performed on clinical samples and autopsy material from human or animals. A total of 50 from 146 samples were positive by specific B1 Toxoplasma PCR assay and then were analyzed by restriction fragment length polymorphism in PCR-amplified SAG2 products. Characterization of the SAG2 gene was successful in 33 (66%) of the samples. Genotyping indicated that 31 (93.9%) were SAG2 type I, 1 was SAG2 type III and 1 was atypical. In birds and cats all samples were SAG2 type I. Results support a predominance of the Toxoplasma SAG2 type I circulating in human and animals in South America.

[Molecular and biological characterization of the CIBMUQ/HDC strain, a reference strain for Colombian Toxoplasma gondii]. / Caracterización biológica y molecular del aislamiento CIBMUQ/HDC, una cepa colombiana de referencia para Toxoplasma gondii.

There are few reports about characterization strains of Toxoplasma gondii that analyze the differences between isolates from Europe or United States with those obtained in South America. The current study analyzes virulence data from the mouse model, the gene SAG2 polymorphism by PCR-RFLP and microsatellite analysis in a single Colombian isolate. The strain was isolated from blood of a child with congenital toxoplasmosis, living in Armenia, Colombia. Analysis of virulence in the mouse showed that this strain has an LD100 of 10 tachyzoites. Both methods of genetic characterization demonstrated that this strain belonged to the clonal type 1 and was called HOM/CTCO/2002/CIBMUQ/BL/HDC (brief name: CIBMUQ/HDC). The CIBMUQ/HDC strain is the first Colombian strain available as a reference strain for national and international researchers.

Caracterización biológica y molecular del aislamiento CIBMUQ/HDC, una cepa colombiana de referencia para Toxoplasma gondii / Molecular and biological characterization of the CIBMUQ/HDC strain, a reference strain for Colombian Toxoplasma gondii

Existen pocos datos sobre la caracterización de cepas de Toxoplasma gondii que analicen las diferencias entre las cepas aisladas de casos humanos en Europa y Estados Unidos con cepas aisladas en Suramérica. Este trabajo presenta los resultados de la caracterización biológica basada en cultivo in vitro y análisis de virulencia en ratón, y la caracterización molecular obtenida por la amplificación del gen multicopia específico de T. gondii (B1), la genotipificación por PCR-RFLP del gen que codifica para el antígeno de membrana SAG2 y el análisis por microsatélites de un aislamiento clínico de toxoplasmosis congénita ocurrido en Armenia (Colombia). El análisis de virulencia en ratón demostró que esta cepa tenía una DL 100 de 10 taquizoítos. La genotipificación y el análisis por microsatélites demostraron que esta cepa pertenecía al tipo clonal 1 y se denominó HOM/CTCO/2002/CIBMUQ/BL/HDC (nombre abreviado: CIBMUQ/HDC). CIBMUQ/HDC se encuentra disponible como cepa de referencia del país para estudios tanto a nivel nacional como internacional

Fiebre nosocomial de origen incierto en una paciente politraumatizada / Nosocomial fever of unknown origin in a patient with polytrauma

No disponible