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Abstract Background Persons with disabilities experience higher risks of mortality as well as poorer health as compared to the general population. The aim of this study is to estimate the correlations between functional difficulties across several domains in six countries. Methods National census data with questions on disability from six countries (Mauritius, Morocco, Senegal, Myanmar, Vietnam, and Uruguay) was used in this study. We performed logistic regressions to assess the extent to which having a functional difficulty in one domain is correlated with having a functional difficulty in each of the other domains and report weighted odds ratios (ORs) overall and within age-groups (‘18–44’ years and ‘45+’ years). Models adjust for age, sex, and location (rural or urban). Sensitivity analyses around different choices of predictors and response variables were conducted. Findings For all countries, reporting a functional difficulty in one domain was consistently and significantly positively correlated with reporting a functional difficulty in other domains (overall) and for each of the two age-groups considered - ‘18–44’ years and ‘45+’ years. All ORs were greater than one. Cognition, mobility, and hearing were the domains that were the most correlated ones with other domains. The highest pairwise correlations were for i/ hearing and cognition; ii/ mobility and cognition. Results were robust to changing the severity thresholds for functional difficulties. Across countries, Uruguay, the only high-income country among the six countries under study, had the lowest correlations between functional domains. Conclusions There are consistent positive associations in the experience of functional difficulties in various domains in the six countries under study. Such correlations may reflect barriers to social services including healthcare services and resources (e.g. assistive devices) that may lead to an avoidable deterioration of functioning across domains. Further research is needed on the trajectories of functional difficulties and on structural barriers that people with functional difficulties may experience in their communities and in healthcare settings in particular. This is important as some functional difficulties may be preventable.

Introduction Psychiatric disorders are common in children, and academic attainment is lower in children with psychiatric disorders. There are few data about the occurrence of mental health problems and the academic attainment among children in Chile. Objectives To determine the occurrence of mental health problems and its association with academic attainment in first-year students of elementary schools in Chile Methods The study was conducted in 39 urban and rural public elementary schools in Chile in 2019. The academic performance was measured using the Woodcock Muñoz IV Battery and the Corsi Bock-Tapping test. Mental health was assessed using the self-report Dominique Interactive and Strengths in children and Difficulties Questionnaire (SDQ) instruments in their parents and teachers. A triangulation of information was conducted between different informants. Results Overall 610 children were included in the analysis (mean age 7.10 years (SD=0.58), 51% women, 36% from rural area). A higher score in mathematics and reading was negatively correlated to a higher score in emotional symptoms, hyperactivity and peer relationship difficulties, separately, based on both teacher- and parent-reported SDQ. The correlation coefficient between reading scores with Dominique Interactive and Strengths externalizing symptoms was -0.22 (p

This paper is a follow-up to previous researches already published regarding the minimization of optical-electrical noise in optical scanning systems OSS, by the implementation of computational techniques for pattern recognition generated by each reference source used to indicate a coordinate that the OSS will be monitoring. Techniques such as linear discriminant analysis LDA and linear regression LR were implemented in order to discriminate the signals caused by other sources different to the references. In order to enhance the efficiency of these models was implemented linear predictive coding LPC and quantiles as features extractors. The results were encouraging with rates of recognition greater than 91.2 %, reaching in some cases an accuracy of 100 %.

Multicenter collaborative networks are essential for advancing research and improving clinical care for a variety of conditions. Research networks are particularly important for central nervous system infections, which remain difficult to study due to their sporadic occurrence and requirement for collection and testing of cerebrospinal fluid. Establishment of long-term research networks in resource-limited areas also facilitates diagnostic capacity building, surveillance for emerging pathogens, and provision of appropriate treatment where needed. We review our experience developing a research network for encephalitis among twelve hospitals in five Peruvian cities since 2009. We provide practical suggestions to aid other groups interested in advancing research on central nervous system infections in resource-limited areas. Keywords: Central nervous system infections, Encephalitis, Epidemiology, Herpes simplex virus, Virology

La presencia de Staphylococcus aureus en los alimentos representa un riesgo potencial para la salud pública; sus enterotoxinas son el principal factor de virulencia. La detección de las enterotoxinas de S. aureus puede realizarse por ELISA, aunque sólo es posible detectar el pool de enterotoxinas SEA, SEB, SEC, SED y SEE. Los objetivos del presente trabajo fueron optimizar dos técnicas de PCR múltiple para la detección de los genes sea, seb, sec, sed y see de S. aureus y caracterizar un conjunto de 115 aislamientos de Staphylococcus spp. asociados a intoxicaciones alimentarias provenientes de diferentes provincias de Argentina. La caracterización se realizó por pruebas bioquímicas, ELISA y PCR. Sesenta y ocho aislamientos (59,1%) fueron positivos por ELISA, mientras que 61 (53%) fueron positivos por PCR. De los aislamientos positivos por PCR, 34 (55,7%) portaron el gen sea, 9 (14,8%) el gen seb, 5 (8,1%) el gen see, 4 (6,5%) el gen sec, 6 (9,9%) los genes sea y seb, 2 (3,3%) los genes sea y sec, y 1 (1,7%) los genes sea y sed. Este es el primer estudio de caracterización genotípica de aislamientos de S. aureus asociados con brotes de intoxicación alimentaria registrados en distintas provincias argentinas.The presence of Staphylococcus aureus in food represents a potential risk to public health, being its enterotoxins the major virulence factor. Enterotoxin detection can be determined by ELISA, but only for the pool of enterotoxins SEA, SEB, SEC, SED and SEE. The main aims of this study were to optimize two PCR techniques for detection of S. aureus sea, seb, sec, sed and see, and to characterize Staphylococcus spp. isolates associated with food intoxication. Two PCR techniques were optimized and 115 Staphylococcus spp. isolates from Ciudad Autónoma de Buenos Aires, and Buenos Aires, Córdoba, and Neuquén provinces were characterized. The characterization was performed by biochemical tests, ELISA and PCR. Sixty-eight isolates (59.1%) were positive by ELISA, while 61 (53%) were positive by PCR. Out of the positive PCR isolates, 34 (55.7%) carried the sea gene, 9 (14.8%) the seb gene, 5 (8.1%) the see gene, 4 (6.5%) the sec gene, 6 (9.9%) were positive for sea and seb genes, 2 (3.3%) for sea and sec genes, and 1 (1.7%) for sea and sed genes. This is the first study of genotypic characterization of S. aureus isolates associated with food intoxication from different provinces of Argentina.

Diarrheal disease continues to be a serious health problem, especially in developing countries. Bloody diarrhea represents approximately 20-30% of all cases and has higher morbidity and mortality. Treatment with antibiotics is beneficial in cases of Shigella, Campylobacter, Yersinia and Salmonella infection, principally in those children with a higher risk of invasive disease. The aims of this study were to detect the bacterial agents associated with bloody diarrhea in children and to determine their antimicrobial susceptibility patterns. Between June 2001 and January 2008, 249 children with bloody diarrhea were studied. Shigella and Shiga toxin-producing Escherichia coli (STEC) were recovered from 48 (19.3%) and 3 (1.2%) of the total of cases, respectively. In 49 out of 249 children, in whom other enteropathogens were investigated, we recovered Campylobacter jejuni from 7 children (14.3%), Salmonella spp. from 2 (4.1%) and Aeromonas spp. from 1 (2%) in addition to Shigella from 7 children (14.3%). Thirty-four (70%) Shigella isolates showed resistance to ampicillin and 13 (27%) to trimethoprim-sulfamethoxazole. All Shigella isolates were susceptible to nalidixic acid, ciprofloxacin and ceftriaxone. Salmonella and STEC isolates were susceptible to all antibiotics assayed. Thus, the use of trimethoprim-sulfamethoxazole or ampicillin would not be appropriate for the empirical treatment of Shigella - associated diarrhea.La enfermedad diarreica es un problema de salud importante, especialmente en los países en desarrollo. La diarrea sanguinolenta representa el 20-30% del total de casos y determina una mayor morbimortalidad. La antibioticoterapia es beneficiosa en casos de infección por Shigella, Campylobacter, Yersinia y Salmonella, principalmente en niños con riesgo elevado de enfermedad invasora. Los objetivos del presente trabajo fueron conocer las bacterias asociadas a diarrea sanguinolenta y determinar su patrón de sensibilidad a los antimicrobianos. Entre junio de 2001 y enero de 2008 se estudiaron 249 niños con diarrea sanguinolenta. Shigella y Escherichia coli productor de toxina Shiga (STEC) se recuperaron de 48 (19,3%) y 3 (1,2%) casos, respectivamente. En la subpoblación de 49 niños cuyo estudio coprobacteriológico fue más completo se aisló, además de Shigella (14,3%), Campylobacter jejuni (14,3%), Salmonella spp. (4,1%) y Aeromonas spp. (2%). Treinta y cuatro (71%) aislamientos de Shigella mostraron resistencia a ampicilina y 13 (27%) a trimetoprima-sulfametoxazol. Todos los aislamientos de Shigella fueron sensibles a ácido nalidíxico, ciprofloxacina y ceftriaxona. Los aislamientos de Salmonella y STEC fueron sensibles a todos los antibióticos ensayados. En función de estos resultados, se concluye que el uso de trimetoprima-sulfametoxazol y de ampicilina no sería apropiado para el tratamiento empírico de la diarrea asociada a Shigella.

En febrero de 2006 ocurrió un brote epidémico de gastroenteritis aguda de origen alimentario, en ocasión de un festejo popular en una pequeña localidad de la provincia de Neuquén, Argentina. Aproximadamente 800 personas participaron de un almuerzo en las instalaciones del Gimnasio Municipal, y unas tres horas después de finalizado, cerca de 150 asistentes consultaron al hospital local, afectados por síndrome gastroentérico agudo. Se realizó una investigación epidemiológica caso-control a través de un muestreo representativo no probabilístico. Los resultados epidemiológicos establecieron un brote de ETA a fuente común, con una relación caso-control de 1:1,8. Los principales síntomas fueron cólicos abdominales (88%), vómitos (73,5%) y diarrea (60%). La torta que se sirvió en ese evento fue identificada como el alimento causal (OR 9,79; IC 95%; 2,66-36,00; valor p = 0,0001), sujeto a condiciones higiénico-sanitarias insatisfactorias en los diferentes procesos de elaboración, conservación y manipulación. De una porción de la torta se aisló una cepa de Staphylococcus aureus subespecie aureus, coagulasa positiva, enterotoxigénica, con un recuento de 2,4x10(6) UFC/g, y también se aisló este microorganismo de tres muestras de manos y narinas de personas involucradas en la preparación y el servicio. Las cepas aisladas de un operador y de la torta portaron el gen sea y presentaron el mismo patrón de SmaI-PFGE. Se atribuyó el brote de ETA a la contaminación durante el proceso de preparación de la torta consumida durante ese almuerzo popular, lo que podría estar relacionado con deficiencias en aspectos higiénicos y con la falta de refrigeración y de mantenimiento de la cadena de frío.In the summer of 2006, an epidemic outbreak of acute gastrointestinal illness related to food consumption occurred in a small town in the province of Neuquén, Argentina. During a popular feast, approximately 800 local residents attended lunch held in the facilities of the Municipal Gymnasium. About three hours later, nearly 150 attendees sought medical assistance at the local hospital due to acute gastroenteritis. A case-control epidemiological investigation was conducted using representative non-probability sampling. The epidemiological investigation showed a common-source foodborne disease outbreak with a case-control ratio of 1:1.8. The main symptoms were abdominal cramps (88%), vomiting (73.5%) and diarrhea (60%). The cake was identified as the source of infection (OR 9.79; IC 95%, 2.66-36.00; p = 0.0001), and unsatisfactory hygienic conditions in food production, conservation and handling steps were identified. Coagulase positive, enterotoxigenic Staphylococcus aureus, subspecies aureus was detected in a piece of cake, with a count of 2.4x10(6) CFU/g, and in samples from the hands and nostrils of three people involved in food preparation and service. The strains isolated from both the cake and one of the food handlers carried the sea gene, and presented the same SmaI-PFGE pattern. The foodborne disease outbreak was considered to be due to contamination in the preparation process of the cake consumed at the feast, which was related to inadequate hygienic conditions, lack of refrigeration and cold chain disruption.

Antecedentes y objetivos: El prejuicio sesga los procesos de categorización, lo que implica asignar ciertas características más allá de los datos objetivamente disponibles. El estereotipo llena el contenido categorial poniendo lo que falta a lo que escasamente conocemos. De un mero dato físico ("estar gordo o gorda") pasamos a categorizar a la persona obesa sobre la base de nuestras creencias, en una íntima fusión entre estereotipo y categorización. Ámbito, población e intervenciones: Tomamos 138 estudiantes y 47 pacientes, con anorexia o bulimia, que asignaron calificativos sobre la personalidad de las personas obesas utilizando un listado de adjetivos. El mismo listado fue entregado a 49 pacientes obesos, para que los usaran con el fin de definir su personalidad. Resultados: Se analizaron los adjetivos más utilizados y las escalas de personalidad correspondientes, aplicando la prueba de X² para determinar las diferencias entre adjetivos y escalas en las muestras. Se consideró significación estadística un valor de p < 0,05 usando la aplicación SPSS v.13. A la hora de definir su personalidad las personas obesas lo hacen de forma muy diferente al grupo control y al de pacientes. Mientras las personas obesas utilizan con mucha más frecuencia adjetivos "positivos", los otros grupos tienden a utilizar adjetivos de connotaciones más "negativas". Parece que los estereotipos introducen un sesgo perceptivo en cuanto a las características de personalidad. El miedo al sobrepeso-obesidad o al hecho de "ganar peso" de los pacientes, explicaría algunos hallazgos del trabajo. Los pacientes atribuyen a las personas obesas algunas características de personalidad, en conjunto, más negativas que las que atribuyen los miembros del grupo control. Conclusiones: Conocer la influencia de los estereotipos en la percepción de la obesidad es fundamental para el acercamiento, sin prejuicios, al paciente de cara a su tratamiento. Los rasgos de personalidad atribuidos a las personas obesas distan mucho de cómo realmente se perciben dichas personas.Background and objectives: The prejudice biases the categorization processes, which implies assigning particular characteristics beyond the objective data available. The stereotype occupies the categorical content by adding what is lacking to what we little know. From a mere physical datum ("he/she is fat") we categorize the obese individual on the basis of our own believes, intimately fusing the stereotype and categorization. Setting, population, and interventions: We included 138 students and 47 patients with anorexia or bulimia that assigned qualifying adjectives of the personality of obese people by using a list of epithets. This same list was provided to 49 obese patients in order to be used to define their own personality. Results: We analyzed the most frequently used epithets and the corresponding scales of personality by applying the X² test to determine the differences between the adjectives and the scales in the samples. We considered a p value < 0.05 as being statistically significant, by using the SPSS v.13 software. Obese people define their personality very differently than the control group and the group of patients does. While obese people more frequently use "positive" adjectives, the other groups tend to use adjectives with more "negative" connotations. It seems that the stereotypes introduce a perception bias regarding the personality characteristics. The fear to overweight-obesity or the fact of "weight gaining" of patients would explain some of the findings of this work. Patients attribute obese people some personality characteristics altogether more negative than those attributed by the people in the control group. Conclusions: Knowing the influence of the stereotypes on obesity perception is essential to approach the patient with no prejudice regarding his/her treatment. The personality characteristics attributed to obese people are far from how these people really perceive themselves.

Establecimos la frecuencia de aislamiento de Escherichia coli productor de toxina Shiga (STEC) a partir de muestras clínicas y de alimentos, así como las características fenotípicas y genotípicas de las cepas recuperadas. Se analizaron 198 muestras fecales de niños con diarrea sanguinolenta (DS), 14 muestras fecales de niños con síndrome urémico hemolítico (SUH) y 220 muestras de carne picada. También se estudiaron 4 cepas STEC aisladas de alimentos embutidos. Se recuperó STEC de 3 (1,5%) de los niños con DS, de 1 (7%) niño con SUH y de 4 (1,8%) de las muestras de carne picada. Todas las cepas fueron eae y ehxA positivas. Los serotipos detectados fueron: O157:H7 (9 cepas), O26:H11 (2 cepas), O111:NM (1 cepa) y O145:HNT (1 cepa). Todas las cepas O157:H7 portaron el subtipo eae-g1; las cepas O26:H11 y O145:HNT portaron el subtipo eae-b1 y la cepa O111:NM portó el subtipo eae-g2/q. Las cepas STEC del mismo serogrupo mostraron alta diversidad genética. En Uruguay STEC no sería agente frecuente de diarrea con sangre en niños. Sin embargo, las cepas recuperadas presentaron los genes asociados con enfermedad severa y 2 de los 3 niños infectados con STEC evolucionaron a SUH. La carne picada y otros alimentos serían vehículos importantes de O157:H7.We have assessed the frequency of Shiga toxin-producing Escherichia coli (STEC) in clinical and food samples as well as studied the genotypic and phenotypic characteristics of the recovered strains. One hundred ninety eight fecal samples from children with bloody diarrhea (BD), 14 from children with hemolytic uremic syndrome (HUS), 220 ground beef samples and 4 STEC isolates from other beef-derived products were analyzed. The STEC strains were isolated from 3 (1.5%) children with bloody diarrhea, 1 (7%) from a child with HUS and 4 (1.8%) from ground beef samples. All strains were eae and ehxA positive. The serotypes found were: O157:H7 (9 strains), O26:H11 (2), O111: NM (1) and O145:HNT (1). All O157:H7 STEC strains harbored the eae subtype g1, O26:H11 and O145:HNT strains, subtype b1 and O111:NM strain, subtype g2/q. The STEC strains of the same serogroup showed high genetic diversity. In Uruguay, STEC is not frequently isolated from cases of bloody diarrhea in children. However, all the recovered STEC strains carried the genes associated with severe disease and 2 out of 3 children infected with STEC developed HUS. Ground beef and other food products might be important vehicles for O157:H7 strains.

Escherichia coli productor de toxina Shiga es un patógeno emergente cuyo principal factor de virulencia son las toxinas Shiga (Stx), codificadas por los genes stx. Estas toxinas se clasifican en 6 tipos (1, 2, 2c, 2d, 2e y 2f) que agrupan a 22 variantes. En Argentina se validaron dos técnicas de PCR para la detección de los genes stx, PCR-MK y PCR múltiple. Los objetivos del trabajo fueron analizar mediante el uso de herramientas bioinformáticas la capacidad de dichas técnicas para detectar las variantes del gen stx y demostrar experimentalmente la amplificación de 8 variantes stx. Se recopilaron 25 secuencias nucleotídicas de la base de datos GenBank correspondientes a 21 variantes de stx. Se utilizó el programa BLAST 2 sequences para analizar la complementariedad de las bases nucleotídicas entre las secuencias de las variantes y las secuencias de los cebadores utilizados en las PCR estudiadas. La técnica de PCR-MK permite detectar los tipos stx1, stx2, stx2c, stx2d y stx2f, aunque no permite detectar el tipo stx2e y tres variantes del tipo stx2c. La PCR múltiple permite detectar los tipos stx1, stx2, stx2c, stx2d, pero no los tipos stx2e y stx2f. Se demostró experimentalmente que ambas técnicas de PCR son apropiadas para la detección de las variantes que están asociadas a enfermedad grave en el hombre.Shiga toxin-producing Escherichia coli is an emergent pathogen, being the Shiga toxin (Stx) the main virulence factor. These toxins are classified into 6 types (1, 2, 2c, 2d, 2e and 2f) and 22 variants. In Argentina, two PCR for stx gene detection, PCR-MK and multiplex-PCR, were validated. The aim of this work was to analyze, by using bioinformatic tools, the stx variants that could be amplified by these PCRs, and to experimentally show the amplification of 8 stx variants. Twentyfive nucleotide sequences were collected from GenBank corresponding to 21 stx variants. The BLAST 2 sequences program was used to analyze the complementarities between the nucleotide sequence of the variants and the primers corresponding to the PCR studied. PCR-MK could detect types stx1, stx2, stx2c, stx2d and stx2f, but not type stx2e and three type stx2c variants. On the other hand, the multiplex-PCR could detect types stx1, stx2, stx2c, stx2d, but not stx2e and stx2f types. It was experimentally determined that both PCRs can detect those variants that cause severe disease in humans.

Escherichia coli productor de toxina Shiga (Stx) (STEC) O157:H7 es un patógeno asociado a enfermedades transmitidas por alimentos, fundamentalmente de origen animal. Se investigó la presencia de E. coli O157 en 250 muestras de carne picada y hamburguesas obtenidas de comercios de las ciudades de Santa Fe y Santo Tomé (Pcia. de Santa Fe) y en 150 muestras de leche provenientes de tanques de enfriado de tambos de la región, utilizando enriquecimiento selectivo y separación inmunomagnética. A partir de 3 muestras de carne (1,2%) se aislaron cepas E. coli O157:H7 stx2, eae, y ehxA positivas, que pudieron ser diferenciadas mediante electroforesis de campo pulsado, fagotipificación y genotipificación de stx. No se aislaron cepas STEC O157:H7 a partir de las muestras de leche. Estos hallazgos confirman la participación de los alimentos de origen animal en la epidemiología de las enfermedades producidas por E. coli O157:H7.Shiga toxin (Stx)-producing Escherichia coli (STEC) is an emergent pathogen associated with foodborne diseases, especially foodstuffs of animal origin. A total of 250 beef samples (ground beef and hamburgers) obtained from retail outlets in Santa Fe and Santo Tomé cities, and 150 milk samples from bulk tank milk from dairy barns of the region were analyzed by selective enrichment and immunomagnetic separation. Escherichia coli O157:H7 stx2, eae and ehxA positive strains were isolated from three (1.2%) beef samples. The strains could be differentiated by pulsed-field gel electrophoresis, phagetyping and genotyping of stx. The milk samples were negative for STEC O157. These findings confirm the role of food of animal origin in the epidemiology of E. coli O157:H7 - associated diseases.

Se determinó la tipibilidad, la reproducibilidad y el poder discriminatorio de ERIC-PCR y ApaI-PFGE para establecer la relación genética de cepas de Pasteurella multocida. Se estudiaron 49 cepas de diferente origen, subespecie, biotipo, grupo capsular, serotipo somático y perfil de resistencia antimicrobiana. Por ERIC-PCR se establecieron 31 patrones, los que presentaron entre 10 y 14 bandas en un rango comprendido entre 0,2 y 1,2 kb. Por ApaI-PFGE se detectaron 37 patrones de restricción, los cuales presentaron entre 7 y 15 bandas bien definidas de 34 a 450 kb. La tipibilidad de ERIC-PCR fue del 100% (T=1) y la de ApaI-PFGE del 94% (T=0,94). La reproducibilidad de ambas técnicas fue del 100% (R=1); sin embargo, el poder discriminatorio de ERIC-PCR fue 93% (D=0,93) y el de ApaI-PFGE 98% (D=0,98). Mediante ambas técnicas fue posible agrupar las cepas con relación epidemiológica y diferenciar claramente las cepas no relacionadas. Se demostró el valor de ERIC-PCR y ApaI-PFGE para complementar estudios epidemiológicos, principalmente si las cepas en estudio son analizadas por ambas técnicas.Typeability, reproducibility, and discriminatory power of ERIC-PCR and ApaI-PFGE to establish the genetic relation of P. multocida strains were determined. Forty-nine strains of different source, biotype, capsular group, somatic serotype, and resistance to antimicrobials were studied. By ERIC-PCR, 31 patterns were defined with 10 to 14 bands in a rank of 0.2 and 1.2 kb. By ApaI-PFGE, 37 restriction patterns were established with 7 to 15 bands of 34 to 450 kb. Typeability was 100% (T=1) for ERIC-PCR, and 94% (T=0.94) for ApaI-PFGE. Reproducibility of both techniques was 100% (R=1). Discriminatory power was 93% (D=0.93) for ERIC-PCR, and 98% (D=0.98) for ApaI-PFGE. By using both techniques, epidemiologically related strains were grouped, and unrelated strains were clearly differentiated. The value of ERIC-PCR and ApaI-PFGE as complements to epidemiologic studies was demonstrated, especially when both techniques were used to analyze the strains.

Treinta cepas de Pasteurella multocida aisladas en la Argentina a partir de muestras de origen humano y animal fueron identificadas, biotipificadas y caracterizadas. Veintidós de ellas (73%) correspondieron a P. multocida subsp. multocida; cinco (17%) a P. multocida subsp. gallicida y tres (10%) a P. multocida subsp. septica. Todas las cepas fueron agrupadas en 8 biotipos; el 70% presentó el tipo capsular A. Los serotipos somáticos más frecuentes fueron el 1 (n:11) y el 3 (n:9). Las cepas de origen porcino fueron resistentes a tiamulina, estreptomicina y tetraciclina. La caracterización de las cepas de P. multocida aisladas en la Argentina es el primer paso para concretar futuros estudios destinados a la prevención y al tratamiento de la pasteurelosis en medicina humana y veterinaria.Thirty Pasteurella multocida strains isolated in Argentina from human and animal samples were identified, biotypified and characterized. Twenty-two (73%) strains were identified as P. multocida subsp. multocida, 5 (17%) as P. multocida subsp. gallicida, and 3 (10%) as P. multocida subsp. septica. All strains were grouped in 8 biotypes, and 70% of the strains presented capsular type A. The most frequent somatic serotypes were 1 (n:11) and 3 (n:9). P. multocida strains from swine source were resistant to tiamulin, streptomycin and tetracycline. Characterization of P. multocida strains isolated in Argentina is the first step to conduct future studies intended for the prevention and treatment of pasteurellosis in human and veterinary medicine.

Entre el 15 de octubre y el 8 de noviembre de 2003 ocurrió un brote de gastroenteritis en un Jardín Maternal de un Hospital de la ciudad de Mar del Plata. Catorce de un total de 80 niños (17,5%), edad promedio 23,6 ± 13,9 meses, presentaron diarrea, y un caso evolucionó a síndrome urémico hemolítico. La madre de uno de los afectados presentó diarrea simultáneamente. No se pudo establecer el origen del brote, pero probablemente la transmisión haya sido fundamentalmente persona a persona. Las prácticas habituales en el lactario del jardín maternal, y las condiciones inadecuadas de infraestructura y hábitos de higiene de la cocina del Hospital fueron señalados como factores de riesgo. En un caso se detectó Escherichia coli productor de toxina Shiga (STEC) O103:H2, y STEC O26:H11 en otro. En el niño infectado por STEC O26:H11, la excreción se extendió por un período de 37 días. La no detección de STEC en aquellos casos en los cuales el intervalo entre el inicio de los síntomas y la toma de muestra fue mayor a 6 días, enfatiza la necesidad de la recolección temprana de especímenes. Las principales conclusiones de este estudio fueron la necesidad de establecer normas óptimas de higiene, informar rápidamente la ocurrencia de casos de gastroenteritis y confirmar la negativización de la excreción del patógeno.From October 15 to November 8, 2003, a gastrointestinal outbreak occurred at a day care center in a Hospital in Mar del Plata City. Fourteen out of 80 (17.5%) children, mean age 23.6 ± 13.9 months, and the mother of one of them had diarrhea. One case developed hemolytic uremic syndrome. No conclusive evidence of the origin of the outbreak was found, but the epidemic curve suggested person-to-person spread. The usual practices at the place where infant milk formula was prepared at the day care center, together with the inadequate infrastructure conditions and hygiene practices at the kitchen of the hospital, were considered risk factors. One case had Shiga toxin-producing Escherichia coli (STEC) O103:H2 infection and other STEC O26:H11.The duration of shedding for the child with O26:H11 infection was 37 days. In the other symptomatic children, the pathogen was not recovered from fecal samples collected 6 or more days after the onset of the illness. This emphasizes that the collection of early samples is necessary to recover STEC strains. In order to prevent and control enteric diseases in day care facilities the following measures are necessary: optimal hygiene standards, early case reporting, and exclusion of those who remain culture-positive.

La infección por Escherichia coli productor de toxina Shiga (STEC) es causa de diarrea con o sin sangre, colitis hemorrágica y síndrome urémico hemolítico (SUH) en humanos. El objetivo de este trabajo fue validar una técnica de PCR múltiple para el diagnóstico de STEC basado en la detección de los genes stx1, stx2 y rfbO157. La validación de la técnica se realizó en dos laboratorios independientes, en forma paralela. Se determinó rango de trabajo, selectividad y robustez. Se evaluó el desempeño de la técnica al combinar distintas concentraciones de dos cepas con diferentes factores de virulencia. El rango de trabajo dependió de la cepa analizada, los valores máximos y mínimos fueron 6,6 x 107 y 1,0 x 104 UFC/50 µl. El límite de detección fue de 1,0 x 104 UFC/50 µl y el límite de corte de 1,0 x 105 UFC/50 µl. La robustez fue óptima al modificar diferentes variables. Se obtuvo 100% de inclusividad, exclusividad, precisión analítica, valor predictivo positivo y valor predictivo negativo. No se observó interferencia al combinar distintas concentraciones de los factores de virulencia blanco de la reacción. La técnica validada es una alternativa apropiada para la detección y confirmación de STEC O157 y no-O157 a partir de cultivos bacterianos.Shiga toxin-producing Escherichia coli (STEC) cause non-bloody or bloody diarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS) in humans. The aim of the present study was to validate a multiplex PCR for the STEC diagnosis based on the detection of stx1, stx2 and rfbO157 genes. The multiplex PCR validation was carried out in two independent laboratories in a parallel way. Work range, selectivity and robustness were established. The PCR performance was evaluated using different concentrations of two STEC strains harboring different target genes. The work range depended on the strain analyzed, the maximum and the minimum values were 6.6 x 107 and 1.0 x 104 CFU/50 µl. The detection limit was 1.0 x 104 CFU/50 µl and the cut limit 1.0 x 105 CFU/50 ml. A good robustness was observed when different variables were introduced. Inclusivity, exclusivity, positive predictivity, negative predictivity and analytical accuracy were of 100%. Interference was not shown when different concentrations of STEC strains, carrying different genes, were used. The validated technique is an appropriate alternative for detection and confirmation of STEC O157 and non-O157 strains from bacterial cultures.

Se aplica el método de optimización de mínimos costos al mecanizado de rolletes de cadena SS-1796, elaborados en untorno automático CNC 42/700 de la Empresa TASIA. Se logra una disminución en 50,4 % del tiempo de producción y semuestra una valoración sobre el uso de refrigerante a velocidades de corte superiores a los 250 m/min.Palabras claves: Optimización ,transmisiones por cadena, refrigerante, velocidad de corte, mecanizado.________________________________________________________________________________AbstractThe minimum cost optimization method is applied to the elaboration of SS-1796 chain rollers which were manufactured in CNC-42/700 automatic lathe in TASIA enterprise. Time production is decreased in 50,4 % and an evaluation of the use of cutting fluidis shown at cutting speeds higher than 250 m/minKey words: Optimization, chain roller transmision, cutting fluid, cutting speed.

In this report we describe the detection and duration of fecal shedding of Shiga toxin-producing Escherichia coli (STEC) O157 and non-O157 in symptomatic and asymptomatic cases during four events occurred among children in day-care centers in Argentina. In each event, the cases were identified among children, family contacts and staff members of the Institution. The isolates were characterized by pheno-genotyping and subtyping methods. The STEC fecal shedding was prolonged and intermittent. Strains O157:H7 (1st event); O26:H11 (2nd event); O26:H11 (3rd event) and O145:NM (4th event) were shed during 23-30, 37, 31 and 19 days, respectively. Considering the possibility of STEC intermittent long-term shedding, symptomatic and asymptomatic individuals should be excluded from the Institution until two consecutive stool cultures obtained at least 48 h apart, test negative.En el presente trabajo se describe la detección y el tiempo de excreción de Escherichia coli productor de toxina Shiga (STEC) O157 y no-O157 en casos sintomáticos y asintomáticos durante cuatro eventos ocurridos en jardines maternales de Argentina. En cada evento se identificaron los casos entre los niños, sus familiares y el personal del jardín. Los aislamientos fueron caracterizados por técnicas feno-genotípicas y de subtipificación. La excreción de STEC fue, en general, prolongada e intermitente. Cepas STEC O157:H7 (1er evento); O26:H11 (2do evento); O26:H11 (3er evento) y O145:NM (4to evento) fueron excretadas durante 23-30, 37, 31 y 19 días, respectivamente. Dadas las características de la excreción, no debe permitirse el reingreso a la institución de todo niño o adulto con infección por STEC, sintomático o asintomático, hasta no tener dos coprocultivos negativos sucesivos, con intervalos de 48 horas entre ellos.

En este trabajo se realiza un análisis cualitativo (y en algunos casos cuantitativos) de las tensiones residuales, de primero ysegundo género, que surgen durante el proceso de soldadura y afilado de las cuchillas de metal duro.______________________________________________________________________AbstractIn this work is accomplished a qualitative analysis (in some instances quantitative) of the residual tensions, of first and secondgender, that emerge during the welding process and sharpened of the hard metal cutters.