Caracterización de agentes bacterianos aislados en brotes de enfermedades transmitidas por alimentos / Characterization of bacterial agents isolated in diseases outbreaks transmitted by foods

Introducción: Las enfermedades transmitidas por alimentos se producen por ingestión de un alimento, incluido el agua, que puede estar contaminado por diversos agentes. Objetivo: Caracterizar los agentes bacterianos aislados en brotes de enfermedades transmitidas por alimentos. Métodos: Se realizó un estudio observacional, descriptivo y transversal de 100,0 % de los brotes de enfermedades transmitidas por alimentos en la provincia de Santiago de Cuba, desde enero de 2018 hasta diciembre de 2019, para lo cual se seleccionaron muestras de alimentos y heces fecales. La caracterización de las bacterias aisladas se basó en los resultados del crecimiento y otras pruebas bioquímicas-metabólicas. Se utilizaron resultados del aislamiento y confirmación de los agentes identificados en cada uno de los brotes a partir de las muestras antes citadas. Entre las variables analizadas figuraron: número de brotes, muestras de alimentos, de heces fecales y resultados de pruebas bioquímicas y metabólicas. Resultados: Se obtuvo un aislamiento de agentes bacterianos en 100,0 % de las muestras de alimentos. Hubo una mayor frecuencia de bacterias Gram negativas (82,0 %) y la menor correspondió a microorganismos Gram positivos (18,0 %). La Salmonella D fue el microorganismo más frecuente. Conclusiones: Este resultado representa un instrumento para el diagnóstico etiológico de los brotes de enfermedades transmitidas por alimentos en Santiago de Cuba.

Introduction: Diseases transmitted by foods are produced due to ingestion of a food, including water that can be contaminated by diverse agents. Objective: To characterize the bacterial agents isolated in diseases outbreaks transmitted by foods. Methods: An observational, descriptive and cross-sectional study of 100.0 % of the diseases outbreaks transmitted by foods in Santiago de Cuba, from January, 2018 to December, 2019 was carried out, for which samples of foods and stools were selected. The characterization of the isolated bacterias was based on the results of growth and other biochemical-metabolic tests. Results of the isolation and confirmation of agents identified in each one of the outbreaks from the samples mentioned above were used. Among the analyzed variables we can mention: number of outbreaks, samples of foods, samples of stools and results of biochemical and metabolic tests. Results: An isolation of bacterial agents was obtained in 100.0 % of foods samples. There was a higher frequency of Gram negative bacterias (82.0 %) and the lower corresponded to Gram positive microorganisms (18.0 %). Salmonella D was the most frequent microorganism. Conclusions: This result represents an instrument for the etiological diagnosis of diseases outbreaks transmitted by foods in Santiago de Cuba.

Evaluation of the novel DiaSorin LIAISON®Campylobacter assay for the rapid detection of Campylobacter spp.

INTRODUCTION: Campylobacter spp. infection is one of the leading causes of foodborne diarrhoeal illness in humans worldwide. The purpose of this study was to evaluate the DiaSorin LIAISON®Campylobacter assay for human campylobacteriosis diagnosis. METHODOLOGY: A total of 645 stool samples from 640 patients suspected of having gastrointestinal infection were included. A stool culture was simultaneously performed with the DiaSorin LIAISON®Campylobacter assay to detect the presence of Campylobacter spp. RESULTS: Taking the conventional culture to be the perfect gold standard, sensitivity and specificity rates of the DiaSorin LIAISON®Campylobacter assay were 100% and 97.7%, respectively; and 99.1% and 98.6%, respectively, when taking the culture to be the imperfect gold standard (Bayesian Model). CONCLUSION: This new assay might be a useful tool especially for the screening of negative results.

Shigella sonnei: ¨Est ocurriendo un cambio en nuestro medio? / Shigella sonnei: is a change occurring in our middle?

Objetivos: Determinar los serogrupos de Shigella como agentes etiol¢gicos de diarrea. Dise¤o: Estudio descriptivo, retrospectivo, anal¡tico. Instituci¢n: Instituto de Medicina Tropical, Universidad Nacional Mayor de San Marcos, Lima, Per£, y Hospital Nacional Daniel A. Carri¢n, Callao, Per£. Material biol¢gico : Aislamientos de Shigella sp. en coprocultivos. Intervenciones: Se revis¢ los aislamientos de Shigella sp. en coprocultivos, durante los a¤os 2010 y 2011, en la base de datos WHONET 5.6 del hospital, tanto de pacientes adultos como pedi tricos, ambulatorios, hospitalizados y atendidos en emergencia. Se distribuy¢ la Shigella por serogrupos. Principales medidas de resultados : Frecuencia absoluta y frecuencia relativa de Shigella sp. Resultados: El a¤o 2010 se aisl¢ 64 Shigellas sp.; 41 correspondieron al serogrupo flexneri (64,1 por ciento) y 20 al serogrupo sonnei (31,3 por ciento). En el a¤o 2011 se aisl¢ 90 Shigellas sp.; 36 correspondieron a serogrupo flexneri (40 por ciento) y 50 al serogrupo sonnei (55,6 por ciento). Las diferencias encontradas son estad¡sticamente significativas. Conclusiones: Shigella sonnei fue el serogrupo predominante en nuestro hospital.

Objectives: To determine Shigella serogroups as diarrhea etiological agents. Design: Descriptive, retrospective, analytical study. Setting: Instituto de Medicina Tropical, Universidad Nacional Mayor de San Marcos, Lima, Peru, and Hospital Nacional Daniel A. Carrion, Callao, Peru. Biologic material: Shigella sp. isolates in coprocultures. Interventions: Shigella sp. isolates in coprocultures of outpatient, hospitalized and emergency adult and pediatric patients attended during years 2010 and 2011were reviewed at the hospital WHONET 5.6 database. Shigella were distributed by serogroups. Main outcome measures : Absolute and relative frequency of Shigella sp. Results: Sisty-four Shigellas sp were isolated in 2010; 41 corresponded to flexneri serogroup (64.1 per cent) and 20 to sonnei serogroup (31.3 per cent). Ninety Shigellas sp. were isolated in 2011; 36 corresponded to flexneri serogroup (40 per cent) and 50 to sonnei serogroup (55,6 per cent). Differences were statistically significant. Conclusions: Shigella sonnei was the predominant serogroup at our hospital.

Novo meio seletivo-indicador para detecção de Aeromonas e Plesiomonas: ágar UNISC / New selective indicator medium for detection of Aeromonas and Plesiomonas: UNISC agar

Avaliou-se um novo meio seletivo-indicador (ágar UNISC) para o isolamento de enteropatógenos clássicos e Aeromonas e Plesiomonas shigelloides. A capacidade de fermentação da xilose é indicada pela coloração amarela (fermentadores) ou azul (não fermentadores) que, aliada à prova da oxidase, constitui-se em indicador para a detecção de Aeromonas spp e Plesiomonas shigelloides. A produtividade e seletividade, avaliadas pelos índice de contagem absoluta e índice de contagem relativa indicam-no como uma alternativa aos coprocultivos clássicos porque permite, num só meio, o isolamento de Escherichia coli, Shigella spp, Salmonella spp, bem como, Aeromonas spp e Plesiomonas shigelloides, favorecendo o diagnóstico laboratorial das gastroenterites.

We evaluated a new selective indicator medium (UNISC Agar) for isolation of classical enteropathogens, Aeromonas spp and Plesiomonas shigelloides. The xylose fermentation capacity is indicated by a yellow color (fermenting agents) or blue (no fermenting agent). This, together with the oxidase test, establishes it as an indicator for detecting Aeromonas and Plesiomonas shigelloides. Its productivity and selectivity, as assessed using the absolute count index and relative count index, indicate it as an alternative to the classical feces culturing media. This is because, in a single medium, it enables isolation of Escherichia coli, Shigella spp and Salmonella spp, in addition to Aeromonas and Plesiomonas shigelloides, thereby favoring the laboratory diagnosis of gastroenteritis.

Hemocultivo, Coprocultivo y Reacción de Widal en la detección de Salmonella Entérica en pacientes con Salmonelosis / The use of blood culture, stool culture and Widal test in the detection of Enteric Salmonella in patients with Salmonellosis

Tipo de estudio: Transversal descriptivo.Objetivos: Identificar el agente etiológico por cultivo en sangre y heces a los pacientes con cuadro clínico sospechoso de salmonelosis, y analizar el verdadero valor de la prueba reacción de Widal de la que se ha hecho un uso indiscriminado.Materiales y Métodos: Se estudiaron 59 pacientes que acudieron a Emergencia del hospital de Infectología “Dr. José Daniel Rodríguez Maridueña”, de ambos sexos, mayores de doce años, entre noviembre 2002 y mayo 2003. Se les realizó hemograma, reacción de Widal, hemocultivo y coprocultivo en el Instituto Nacional de Higiene y Medicina Tropical “Leopoldo Izquieta Pérez”.Resultados: Se aisló salmonela Typhi en el 3,8% de hemocultivos realizados a pacientes con RW positiva y sospecha de fiebre tifoidea; en el 21,7% de los pacientes que presentaban clínica más leucopenia y en el 25%, con clínica, leucopenia y RW positiva. Se aisló enterobacterias en el 12% de los pacientes con gastroenteritis; 5% salmonela no tifoideas grupo C, 5% E. Coli y, 2% shiguela.Conclusiones: Se confirmó que la RW no es concluyente en el diagnóstico de Fiebre Tifoidea, y que el cuadro clínico de gastroenteritis por salmonela es indiferenciable del ocasionado por otros agentes bacterianos o no.

Type of study: Transversal descriptive.Objectives: Identify the etiologic agent by blood and stool culture and analize the real value of Widal test.Materials and Methods: 59 patients with clinical features of salmonellosis that went to the emergency room of the Infectology Hospital José Daniel Rodriguez Maridueña of both sexs, older than twelve years old were studied between November 2002 and May 2003. Hemogram, Widal test, blood culture and stool culture were done to each one.Results: Typhoid salmonella was isolated in 3,8% of blood cultures of positive Widal test and suspected of having typhoid fever, in the 21.7% of patients with clinical symptoms and leukopenia and in the 25% of patients with clinical symptoms, leukopenia and positive Widal test. Enterobacterias were isolated in 12% of gastroenteritis patients; 5% group C no Typhi Salmonella, 5% E coli, and 2% shiguella.Conclusions: We confirmed that Widal Test is not conclusive in the typhoid fever diagnosis and that the clinical features of salmonella gastroenteritis is indistinguishable from those caused by other bacterial or not bacterial agents.