Antigenic stimulation during pregnancy modifies specific iga1 and iga2 subclasses in human colostrum according to the chemical composition of the antigen

ABSTRACT Background: Several studies have evaluated the effect of infectious diseases and vaccine protocols during pregnancy on maternal milk immunoglobulin (Ig) levels, to understand the protection conferred by lactation on newborns. Colostrum is the primary source of maternal IgA for the newborn. IgA participates in protection mechanisms in the neonate's mucosa. In humans, IgA has two subclasses with differential anatomical distribution among mucosal compartments. Total IgA levels in maternal milk vary after antigen stimulation and have differential affinities in function of the chemical composition of the antigens. We studied the effect of antigenic stimulation during pregnancy on the concentrations of specific IgA1 and IgA2 subclasses in human colostrum. Methods: We analyzed data from 113 women in Mexico City and compared the amount of IgA subclasses in colostrum against three antigens: two from vaccine protocols (tetanus toxoid and pneumococcal polysaccharides) and lipopolysaccharide, a ubiquitous antigen in the gastrointestinal tract. Results: In agreement with the previous reports, we showed that IgA1 from colostrum mainly recognized protein antigens; in sharp contrast, IgA2 was mostly directed against polysaccharide antigens. These levels increased in women who had previous contacts through vaccination or infections during pregnancy. Conclusions: Antigen interaction during pregnancy increased the amount of specific IgA subclasses, depending on the chemical composition of the antigen.

Presencia de los genes de toxigenicidad nheA, nheBy nheC en cepas de Bacillus cereus aisladas de leches deshidratadas en Costa Rica / Detection of toxigenic genes nheA, nheB and nheC in Bacillus cereus strains isolated from powdered milk samples in Costa Rica

La leche en polvo es un producto de alto consumo humano que no precisa de ser conservado en frío, no obstante, diversos microorganismos pueden deteriorarlo. En la población costarricense, también se observa este alto consumo, por la facilidad del alimento para transporte, preparación y su costo competitivo. Bacillus cereus es una bacteria potencialmente patógena asociada a este tipo de producto, capaz de desarrollar toxinas dependiendo de la presencia o ausencia de los respectivos genes codificantes. En este estudio se determinó la presencia de los genes toxigénicos nheA, nheB y nheC en cepas de B. cereus aisladas de leche deshidratada vendida en el mercado nacional costarricense.Se examinaron cinco lotes diferentes, de diez marcas comerciales de leche en polvo distribuidos en el área metropolitana de San José Costa Rica. Se procedió a cuantificar B. cereus en las muestras de leche en polvo mediante la técnica de Número Más Probable (NMP) e identificar los aislamientos utilizando el equipo automatizado Vitek®. Adicionalmente, se determinó la presencia de los genes nheA, nheB y nheC mediante la técnica de PCR. La frecuencia de aislamiento de Bacillus cereus en las muestras de leche en polvo analizadas alcanzó un 50%, con cantidades que oscilaron entre 3 y >100 NMP/g. Se recuperaron 19 cepas de B. cereus aisladas, cinco fueron positivas para los tres genes toxigénicos, lo cual revela la presencia de B. cereus potencialmente toxigénico en leches deshidratadas del mercado nacional, lo que representa un riesgo para la salud pública.

Powdered milk is a frequently consumed product that does not need to be kept under cold conditions. Nevertheless, different microorganisms may contaminate it. Powdered milk is a highly consumed product by Costa Rican population, and Bacillus cereus is a potentially pathogenic bacteria associated to it, with the ability to develop toxins depending on the presence of the respective codifying genes. The aim of this study was to determine the presence of the toxigenic genes nheA, nheB and nheC from B. cereus strains, found in powdered milk sold at the Costa Rican national market. Five different lots of ten brands of powdered milk, distributed in the metropolitan area of San José, Costa Rica were analyzed. B cereus load was quantified using the Most Probable Number technique and identified using the Vitek® system. The presence of the toxigenic genes was determined using the PCR technique. The isolation frequency of this bacteria in the powdered milk samples analyzed reached 50%, with populations ranging from 3 to >100 MPN/g. Five out from nineteen strains were found positive for the three toxigenic genes, indicating contamination with potentially toxigenic B. cereus in powdered milk distributed in the national market, and an important risk for public health.

Evaluation of growth in diesel fuel and surfactants production ability by bacteria isolated from fuels in Costa Rica / Evaluación de crecimiento en combustible diesel y capacidad de producción de surfactantes en bacterias aisladas de combustibles en Costa Rica

A total of 149 bacterial strains previously isolated from fuels stored in Costa Rica were selected in terms of their ability to grow aerobically in diesel and produce bioemulsifier active compounds. The diesel growth was evaluated by a redox-indicator based test, and surfactant production was estimated indirectly by both the emulsification index determination (E24) and hemolytic activity. Twenty-six strains (16.8%) were considered as capable of growing in diesel, while surfactant production was detected in 22 (14.8%), estimated according to E24. Seven strains showed high production of biosurfactants (E24 ≥ 50%), headed by Pseudomonas aeruginosa 148D-O, P. aeruginosa 87R-B and Bacillus pumilus 133S-B. No significant correlation was observed between hemolytic patterns and growth outcomes in diesel or E24. Surfactant producing strains should be studied further to assess its potential applications.

Un total de 149 cepas bacterianas previamente aisladas de combustibles almacenados en Costa Rica fueron seleccionadas en términos de sus habilidades para crecer aeróbicamente en diesel y producir compuestos con actividad bioemulsificante. El crecimiento en diesel fue evaluado por medio de un test basado en un indicador redox, y la producción de surfactantes fue estimada indirectamente con las determinaciones del índice de emulsificación (E24) y la actividad hemolítica. Veintiseis cepas (16,8%) fueron consideradas como capaces de crecer en diesel, mientras que la producción de surfactantes fue detectada en 22 (14,8%), estimado de acuerdo con el E24. Siete cepas mostraron alta producción de biosurfactantes (E24 ≥ 50%), encabezadas por Pseudomonas aeruginosa 148D-O, P. aeruginosa 87R-B y Bacillus pumilus 133S-B. No se observó correlación significativa entre los patrones de hemólisis y los resultados de crecimiento en diesel o E24. Las cepas productoras de surfactantes deben ser estudiadas más a fondo para evaluar sus potenciales aplicaciones.

Bacterial contamination of automotive fuels in a tropical region: the case of Costa Rica

Microbial contamination of fuel has been the cause of several problems in transportation and storage of these products. Due to the lack of previous studies related to these problems in Costa Rica, bacterial quality was evaluated biannually in automotive fuels stored in the four oil distribution facilities of the Costa Rican Petroleum Refinery (RECOPE). In 12 oil storage tanks, for a total of 96 samples, mesophilic, heterotrophic aerobic/facultative counts (ASTM D6974-04) and identification of bacteria presented in regular gas, premium gas and diesel from the bottom and superior part of the tanks were done; in the samples containing an aqueous phase, sulfate reducing bacteria (SRB) were also quantified by the most probable number technique (MPN), according to the ASTM D4412-84 standard. The higher contamination was shown at the bottom of the tanks (populations up to 10(4) UFC/l), especially if there was accumulated water, in which case populations reached 10(8) UFC/l. The most contaminated fuel was diesel (counts up to 10(4) UFC/l), whereas the less contaminated was premium gas. The less contaminated fuels were from the facilities of La Garita and Barranca, whereas the most contaminated were from Ochomogo. Nevertheless, the quantified populations did not cause significant alteration in quality physicochemical parameters in the samples analyzed. A total of 149 bacterial strains were isolated, 136 (91.3%) Gram positive and 13 (8.7%) Gram negative. The most frequent genera were Staphylococcus (24.0%), Micrococcus (21.9%), Bacillus (18.8%) and Kocuria (11.5%) among Gram positive bacteria and Pseudomonas (7.3%) among Gram negative bacteria. The majority of these genera have been found as fuel contaminants or even as degraders of this kind of products; nevertheless, some species for which their appearance or growth in hydrocarbons have not been described were found with low frequencies. SRB were present in counts up to 10(5) MPN/l in 42.9% of water containing samples (including all from diesel tanks), indicating biocorrosion processes risk in fuel transport and storage systems. From the findings in this study it is recommended to give a frequent maintenance to fuel containers, based on continuous drainage and removal of accumulated water, antimicrobial agent addition and microbial quality monitoring in country’s fuels. Rev. Biol. Trop. 57 (3): 489-504. Epub 2009 September 30.

Se evaluó semestralmente durante dos años la calidad bacteriana de los combustibles almacenados en los cuatro planteles de la Refinadora Costarricense de Petróleo (Costa Rica). Para un total de 96 muestras se realizaron recuentos (norma ASTM D6974-04) e identificación de las bacterias presentes en gasolina regular, gasolina súper y diesel en los niveles superior e inferior de los tanques contenedores; en las muestras con fase acuosa se cuantificaron las bacterias reductoras de sulfato (SRB, norma ASTM D4412-84). La mayor contaminación se observó en el fondo de los tanques, sobretodo si se presentó una capa de agua almacenada. El diesel fue el combustible más contaminado, sin embargo, no se observó alteración importante en los parámetros fisicoquímicos de las muestras evaluadas. Se aislaron 149 cepas, 136 (91.3%) Gram positivas y 13 (8.7%) Gram negativas; los géneros más frecuentes fueron Staphylococcus (24.0%), Micrococcus (21.9%), Bacillus (18.8%), Kocuria (11.5%) y Pseudomonas (7.3%). Con bajas frecuencias se encontraron algunas especies para las que no se ha descrito su aparición o crecimiento en hidrocarburos. Las SRB se presentaron con recuentos de hasta 105 MPN/l en un 42.9% de las muestras con agua residual, principalmente en diesel, lo cual es indicativo de alerta por biocorrosión. A partir de los resultados se recomienda dar un mantenimiento frecuente a los contenedores, la adición de compuestos antimicrobianos y el monitoreo de la calidad microbiana de los combustibles del país.

Colgajo anal cutáneo por deslizamiento: su utilización en patología ano orificial benigna / Anal cutaneous hanging tatter for slide: his utilization in pathology anus orificial benign

Desde Julio del año 2004 a Septiembre del año 2008, se trataron 34 pacientes que presentaban patología ano-orificial beningna, mediante la realización del colgajo anal cutáneo por deslizamiento. La edad promedio fue de 59 años y el sexo predominante el masculino. Las patologías que presentaban fueron, enfermedad hemorroidal el 64%; estenosis anal 18% y fisura anal 18% del total de enfermos operados el 22% tenían como antecedente cirugía previa y de ellos el 50% fue por hemorroidectomía. La constipación crónica se asocia en un 98% a fisura anal; 65% a enfermedad hemorroidal y un 47% a estenosis del ano. El dolor anal presente en el 100% de los enfermos con estenosis anal y en un 92% en fisura anal. La proctorragia se presentó en el 85% de los pacientes con enfermedad hemorroidal; 73% en isura anal en un 40% en la estenosis anal.

Since July 2004 until September 2008, 34 patients with benign anal pathologywere treated by means of sliding skin anal grafts. The average was 59 years old and there were mostly male.The pathology that they presented was 64% hemorrhoids, 18% anal stenosisand 18% anal fissure; 22% of the patients had a previous surgery and 50% of them have had hemorroidectomy. Chronic head colding is associated with anal fissure in 98%, hemorrhoids in 65% and anal stenosis in 47% of the patients. Anal pain was present in 100% of the patients with anal stenosis and in 92% of the patients with anal fissure. Anal bleeding had been present in 85% of patients with hemorrhoids, 73% in anal fissure and 40% in anal stenosis. Before surgery 6 patients have had different incontinence degree, 3 referred to soild their underwear, 2 of them referred gases incontinence and 1 liquid soiling. Patients under sliding skin anal grafts surgery had a significant improvement; 28 days after surgery all of them had normal continence. Before surgery 7 patients had diminution of the anal diameter verified by the interrogatory and rectal tact. After 21 days from surgery, such diameter was considered as normal. Colonical cleanness is been made with monosodic/ bisodic phosphate with excellent results in all the patients. All patients received monodosis of antibiotic prophylactic with ciprofloxacin and metronidazol. Two patients (5.88%) had infection, because of that they received 7 days of antibiotics, resolving the infection completely. In 94% of the patients the anesthesia used was riding saddle subarachnoid blockade with hyperbaric bupivacaine, in all the cases the results were excellent. After surgery, 70% of the patients referred the pain as light, 20% as moderate and less than 10% as severe. Skin graft vitality was satifactory in100% of patients, 76% very go...

Nickel biosorption by Acinetobacter baumannii and Pseudomonas aeruginosa isolated from industrial wastewater

Nickel biosorption ability was evaluated in two bacterial strains: Acinetobacter baumannii UCR-2971 and Pseudomonas aeruginosa UCR-2957, resulting in greatest adsorption at pH 4.5 and a residence time of 100 minutes. Biosorption isotherms showed that the process follows the Langmuir model. The maximum adsorption rates (Nmax) were 8.8 and 5.7 mg·g-1 for A. baumannii and P. aeruginosa, respectively; however, affinity constants suggest that P. aeruginosa (K=1.28) has higher affinity for nickel than A. baumannii (K=0.68). It is suggested that both strains could be used for wastewater treatment, as long as the concentration of Ni2+ is within the range of mg·L-1.

Foi avaliada a capacidade de adsorção do Ni2+ por duas bactérias, Acinetobacter baumannii e Pseudomonas aeruginosa, em pH 4.5 com tempo de contato de 100 minutos. Isotermas de adsorção foram calculadas com as duas linhagens. Observou-se que, para ambas, o processo de adsorção está de acordo com o modelo fisicoquímico de Langmuir. A captação máxima do Ni2+ (Nmax) foi 5.7 e 8.8 mg Ni2+ g-1 para P. aeruginosa e A. baumannii, respectivamente. Não obstante, P. aeruginosa apresenta uma constante de afinidade (K=1.28) maior que A. baumannii (K=0.68). Estes resultados indicam que ambas as linhagens são adequadas para o tratamento de águas contaminadas, desde que a concentração de níquel seja da ordem de mg·L-1.

Indigencia y ancianidad / Indigence and the aged

Se hace una descripción tipológica del anciano indigente en la ciudad de Bogotá através de la revisión de las historias clínicas del total de ancianos atendidos entre 1980 - 1984 en una Institución pública de la ciudad. Se describen las diferentes causas concurrentes en el proceso de la indigencia del anciano y su evolución histórica, con miras a dar piso a la planeación de futuras intervenciones y soluciones. Se plantea la necesidad de un nuevo estilo de trabajo para el futuro