Development of a visual Adhesion/Invasion Inhibition Assay to assess the functionality of Shigella-specific antibodies.

Introduction: Shigella is the etiologic agent of a bacillary dysentery known as shigellosis, which causes millions of infections and thousands of deaths worldwide each year due to Shigella's unique lifestyle within intestinal epithelial cells. Cell adhesion/invasion assays have been extensively used not only to identify targets mediating host-pathogen interaction, but also to evaluate the ability of Shigella-specific antibodies to reduce virulence. However, these assays are time-consuming and labor-intensive and fail to assess differences at the single-cell level. Objectives and methods: Here, we developed a simple, fast and high-content method named visual Adhesion/Invasion Inhibition Assay (vAIA) to measure the ability of anti-Shigellaantibodies to inhibit bacterial adhesion to and invasion of epithelial cells by using the confocal microscope Opera Phenix. Results: We showed that vAIA performed well with a pooled human serum from subjects challenged with S. sonnei and that a specific anti-IpaD monoclonal antibody effectively reduced bacterial virulence in a dose-dependent manner. Discussion: vAIA can therefore inform on the functionality of polyclonal and monoclonal responses thereby supporting the discovery of pathogenicity mechanisms and the development of candidate vaccines and immunotherapies. Lastly, this assay is very versatile and may be easily applied to other Shigella species or serotypes and to different pathogens.

Shigella Vaccines: The Continuing Unmet Challenge.

Shigellosis is a severe gastrointestinal disease that annually affects approximately 270 million individuals globally. It has particularly high morbidity and mortality in low-income regions; however, it is not confined to these regions and occurs in high-income nations when conditions allow. The ill effects of shigellosis are at their highest in children ages 2 to 5, with survivors often exhibiting impaired growth due to infection-induced malnutrition. The escalating threat of antibiotic resistance further amplifies shigellosis as a serious public health concern. This review explores Shigella pathology, with a primary focus on the status of Shigella vaccine candidates. These candidates include killed whole-cells, live attenuated organisms, LPS-based, and subunit vaccines. The strengths and weaknesses of each vaccination strategy are considered. The discussion includes potential Shigella immunogens, such as LPS, conserved T3SS proteins, outer membrane proteins, diverse animal models used in Shigella vaccine research, and innovative vaccine development approaches. Additionally, this review addresses ongoing challenges that necessitate action toward advancing effective Shigella prevention and control measures.

Etiology of bacterial diarrhea in large cities, mid-sized/small cities and rural areas of China / 中华流行病学杂志

Objective: To understand the etiological characteristics of bacterial diarrhea in different areas, including large cities, mid-sized/small cities and rural area, in China. Methods: A cross-sectional surveillance was conducted in 17 provinces of China from 2010 to 2014. The acute diarrhea outpatients were selected from clinics or hospitals in large cities, mid-sized/small cities, including rural-urban fringe zones, and rural areas. The demographical and clinical characteristics of the patients were collected by using questionnaire, and stool samples were taken from them for laboratory detection of 17 kinds of bacteria. The differences in pathogen positive rates (PPR) and pathogen spectrum across the cases from three-type areas were compared. The different infection risk in different cases were analyzed with unconditional logistic regression model. Results: In our study, we enrolled 9 253 cases from large cities, 5 138 cases from rural areas and 13 683 cases from midsized/small cites. The pathogen with largest differences in infection rate across the three-type areas was Shigella (S.) flexneri (rural area: 5.81%, mid-sized/small city: 2.78%, large city: 0.46%), followed by Aeromonas (A.) hydrophila (rural area: 2.14%, mid-sized/small city: 0.96%, large city: 0.48%). Compared with cases in large cities, the cases in mid-sized/small cities and rural areas had higher infection risks for S. flexneri (mid-sized/small city: OR=6.481, 95%CI: 4.666-9.002, rural area: OR=11.304, 95%CI: 8.018-15.938) and A. hydrophila (mid-sized/small city: OR=1.992, 95%CI:1.401-2.832, rural area: OR=4.083, 95%CI: 2.833-5.884). The constituent ratio of diarrheagenic Escherichia coli and Salmonella increased with the urbanization development, while the ratios of Shigella and A. hydrophila had an opposite trend. S. sonnei (60.00%) was the predominant serogroup of Shigella in urban infections, while S. flexneri (77.37%) was the predominant serogroup in rural infections. Conclusion: The differences in pathogen spectrum of bacterial diarrhea were obvious across large cities, mid-sized/small cities and rural areas in China, especially the differences in the infection rates of S. flexneri and A. hydrophila.

Shigella sp: um problema de saúde pública / Shigella sp: a public health problem

O aumento do consumo de refeições fora de casa está associado ao aumento das Doenças Veiculadas por Alimentos (DVA), que são provenientes do consumo de alimentos e água contaminados, principalmente, devido à falta de higiene no preparo dos alimentos e à ausência, em muitos casos, do tratamento da água usada no preparo destes alimentos. A shigelose é uma DVA que se caracteriza como uma doença inflamatória do trato gastrointestinal causada pela Shigella cujos sintomas e características se assemelham à salmonelose. O gênero Shigella possui quatro espécies: S. dysenteriae, S. flexneri, S. boydii e S. sonnei. Para a realização deste trabalho foi realizado levantamento de artigos publicados em revistas científicas sobre o tema, com o objetivo de verificar a incidência de Shigella em alimentos abordando suas características e danos provocados à saúde.(AU)

Relationship among Shigella spp. and enteroinvasive Escherichia coli (EIEC) and their differentiation

Shigellosis produces inflammatory reactions and ulceration on the intestinal epithelium followed by bloody or mucoid diarrhea. It is caused by enteroinvasive E. coli (EIEC) as well as any species of the genus Shigella, namely, S. dysenteriae, S. flexneri, S. boydii, and S. sonnei. This current species designation of Shigella does not specify genetic similarity. Shigella spp. could be easily differentiated from E. coli, but difficulties observed for the EIEC-Shigella differentiation as both show similar biochemical traits and can cause dysentery using the same mode of invasion. Sequencing of multiple housekeeping genes indicates that Shigella has derived on several different occasions via acquisition of the transferable forms of ancestral virulence plasmids within commensal E. coli and form a Shigella-EIEC pathovar. EIEC showed lower expression of virulence genes compared to Shigella, hence EIEC produce less severe disease than Shigella spp. Conventional microbiological techniques often lead to confusing results concerning the discrimination between EIEC and Shigella spp. The lactose permease gene (lacY) is present in all E. coli strains but absent in Shigella spp., whereas β-glucuronidase gene (uidA) is present in both E. coli and Shigella spp. Thus uidA gene and lacY gene based duplex real-time PCR assay could be used for easy identification and differentiation of Shigella spp. from E. coli and in particular EIEC.

Sensibilidad a azitromicina y otros antibióticos en aislados recientes deSalmonella, Shigella y Yersinia / Susceptibility to azithromycin and other antibiotics in recent isolates of Salmonella, Shigella andYersinia

INTRODUCCIÓN: La azitromicina constituye una alternativa antibiótica en la diarrea bacteriana. Existen pocos datos en España de sensibilidad a azitromicina de enteropatógenos. Métodos Se determinaron las CMI de azitromicina por E-test en aislados de Salmonella no typhi (SNT), Shigella y Yersinia de los últimos 3 años (2010-2012). También se estudió la sensibilidad a los antibióticos habitualmente utilizados en la clínica diarreica mediante un método de microdilución. Resultados De las 139 cepas de SNT, Shigella y Yersinia, 138 tuvieron una CMI ≤ 16 mg/l de azitromicina. En adultos, el 14,7 y el 40,6% de las cepas de SNT y Shigella, respectivamente, mostraron resistencia al menos a 2 de los siguientes antibióticos: amoxicilina, cotrimoxazol y ciprofloxacino. En población pediátrica, el 10% de los aislados de SNT y el 28,6% (2/7) de Shigella presentaron resistencia combinada a amoxicilina y cotrimoxazol. Conclusiones La azitromicina sería una elección antibiótica útil en el tratamiento de diarrea bacteriana en nuestro medio

INTRODUCTION: Azithromycin represents an alternative option to treat bacterial diarrhea when the antibiotic therapy is indicated. Little is known regarding the susceptibility to azithromycin in enteropathogensin Spain. METHODS: TheMICs of azithromycin were determined by E-test against Salmonella non-typhi(SNT), Shigella and Yersinia isolates collected over the last three years (2010-2012). In addition, the susceptibility to other antibiotics usually used to treat gastrointestinal diseases was determined in these isolates by using a microdilution method. RESULTS: A total of 139 strains of SNT, Shigella and Yersinia were studied. All of them, except one strain, had a MIC ≤ 16 mg/L of azithromycin. In the adult population, 14.7% and 40.6% of SNT and Shigella isolates, respectively, were resistant to at least 2 of following antibiotics: amoxicillin, trimethoprim-sulfamethoxazole and ciprofloxacin. In the pediatric population, 10% of SNT clinical isolates and 28.6% (2/7) of Shigella isolates were resistant to amoxicillin and trimethoprim-sulfamethoxazole. CONCLUSIONS: In our experience, azithromycin would be a useful antibiotic alternative to treat bacterial diarrea

Patrones de sensibilidad y comportamiento clínico de la infección por Shiguella en pacientes pediátricos / Patterns of sensitivity and clinical behavior of Shigella infection in pediatric patients

Objetivos: Identificar los patrones de sensibilidad y el comportamiento clínico de la infección por Shigella en los pacientes pediátricos atendidos en el Hospital Nacional Docente Madre Niño San Bartolomé en el periodo comprendido entre Junio del 2010 a Mayo del 2013. Material y métodos: Se realizó un estudio observacional, descriptivo, retrospectivo y transversal. Se revisaron 82 historias clínicas de los pacientes con diagnóstico de infección por Shigella; en el periodo que corresponde al estudio. Resultados: La media de la edad global fue de 7.5+/-2.7 años. La media de la edad de los varones fue de 7.4+/-2.3 años y de las mujeres fue de 7.6+/-3.1 años. El 57.3 por ciento de los casos fueron de sexo masculino. El 32.9 por ciento de los niños consumían alimentos de riesgo. El 13.4 por ciento de los pacientes habían tenido contacto con diarrea. El 41.5 por ciento de los pacientes habían tenido varias patologías previas. El 32.9 por ciento de los pacientes habían tenido diarreas anteriores. El síntoma inicial fue la diarrea en el 64.6 por ciento de los casos. El 56.1 por ciento de los pacientes tuvo vómitos. El 45.1 por ciento de los pacientes cursó con fiebre (38-39 grados centígrados). El 52.4 por ciento de los pacientes tuvo dolor abdominal. La diarrea con moco se presentó en un 37.8 por ciento de los casos. El 79.3 por ciento de los paciente recibieron el plan A de rehidratación. La comorbilidad más frecuente fue la rinofaringitis en un 18.3 por ciento de los casos. El 50 por ciento de los pacientes tuvieron una reacción inflamatoria con más de 100 leucocitos por campo. Conclusiones: Hubo una mayor frecuencia de sensibilidad a la ciprofloxacina y azitromicina y hubo una mayor frecuencia de resistencia al cloranfenicol. La mayoría provenía del cercado de Lima, contaban con saneamiento en sus domicilios, contaban con sus vacunas y acudían a control CRED. Una minoría consumía alimentos de riesgo, habían tenido contacto con diarrea. El síntoma inicial fue la...

Goals: To identify the patterns of sensibility and clinical behavior of Shigella infection among pediatric patients attended at San Bartolome Hospital, between June 2010 and May 2013. Methods and materials: An observational, descriptive, retrospective and cross-sectional study was designed. Medical records of 82 patients with diagnosis of Shigella infection were checked; in the period of time corresponding to the study. Results: The mean global age was 7.5 +/- 2.7 years old. The boys mean age was 7.4 +/- 2.3 years old and girl’s was 7.6 +/- 3.1 years old. 57.3 por ciento of all cases were male, and 32.9 per cent consumed risky food. 13.4 per cent of patients have had contact with diarrhea. 41.5 per cent have had many other previous diseases. 32.9 per cent have had previous diarrheas. The main symptom was diarrhea in 64.6 per cent of all cases. 56.1 per cent of patients had vomits. 45.1 per cent had fever (38-39 grades centigrade). 52.4 per cent had abdominal pain. Diarrhea with mucus was present in 37.8 per cent of cases. 79.3 per cent of patients received A plan for rehydration. The most common comorbidity was rhinopharyngitis with 18.3 per cent of all cases. 50 per cent of patients had a positive inflammatory cells in stools, with more than one hundred of leukocytes. Conclusions: There was a predominant sensibility of Shigella to Ciprofloxacin and Azithromycin, and there was an important resistance to Chloramphenicol. Most of the patients were from Cercado de Lima, had sanitation at their homes, had their vaccines on time and came to CRED control. A minority consumed risk food and had contact with diarrhea. Initial symptom was diarrhea, most patients had vomiting, fever, abdominal pain, diarrhea with mucus. The most commonly used therapies were ciprofloxacin and azithromycin. Most patients had inflammatory reaction with more than 100 leukocytes per field.

Shigella in Brazilian children with acute diarrhoea: prevalence, antimicrobial resistance and virulence genes

Diarrhoeal disease is still considered a major cause of morbidity and mortality among children. Among diarrhoeagenic agents, Shigella should be highlighted due to its prevalence and the severity of the associated disease. Here, we assessed Shigella prevalence, drug susceptibility and virulence factors. Faeces from 157 children with diarrhoea who sought treatment at the Children's Hospital João Paulo II, a reference children´s hospital in Belo Horizonte, state of Minas Gerais, Brazil, were cultured and drug susceptibility of the Shigella isolates was determined by the disk diffusion technique. Shigella virulence markers were identified by polymerase chain reaction. The bacterium was recovered from 10.8% of the children (88.2% Shigella sonnei). The ipaH, iuc, sen and ial genes were detected in strains isolated from all shigellosis patients; set1A was only detected in Shigella flexneri. Additionally, patients were infected by Shigella strains of different ial, sat, sen and set1A genotypes. Compared to previous studies, we observed a marked shift in the distribution of species from S. flexneri to S. sonnei and high rates of trimethoprim/sulfamethoxazole resistance.

Characterization of Shigella spp. by antimicrobial resistance and PCR detection of ipa genes in an infantile population from Porto Velho (Western Amazon region), Brazil

The incidence of Shigella spp. was assessed in 877 infants from the public hospital in Rondônia (Western Amazon region, Brazil) where Shigella represents the fourth cause of diarrhea. Twenty-five isolates were identified: 18 were Shigella flexneri, three Shigella sonnei, three Shigella boydii and one Shigella dysenteriae. With the exception of S. dysenteriae, all Shigella spp. isolated from children with diarrhea acquired multiple antibiotic resistances. PCR detection of ipa virulence genes and invasion assays of bloody diarrhea and fever (colitis) were compared among 25 patients testing positive for Shigella. The ipaH and ipaBCD genes were detected in almost all isolates and, unsurprisingly, all Shigella isolates associated with colitis were able to invade HeLa cells. This work alerts for multiple antibiotic resistant Shigella in the region and characterizes presence of ipa virulence genes and invasion phenotypesin dysenteric shigellosis.

Diferença de patogenicidade entre Escherichia coli enteroinvasora e Shigella flexneri em modelo experimental de infecção intestinal / Diference in pathogenicity between enteroinvasive Escherichia coli and Shigella flexneri in an experimental model of intestinal infection

Neste trabalho, esclarecemos tópicos da patogenicidade de EIEC que sustentam a sua menor virulência quando comparada à S. flexneri, e mostramos a importância das células dendríticas (CD) nesse processo. Estudou-se o comportamento de EIEC e S. flexneri quando em contato com células Caco-2, avaliando-se uma cinética de expressão dos genes envolvidos na invasão e disseminação bacteriana. Em geral, todos os genes foram menos expressos em EIEC, fato corroborado pelo fenótipo de disseminação bacteriana, onde EIEC foi menos eficiente do que Shigella. Também foi avaliada a modulação da resposta inflamatória de células dendríticas intestinais murinas pela produção de citocinas, expressão de moléculas co-estimulatórias e apresentação de antígenos, após desafio das células com as bactérias. Os resultados sugerem que EIEC induz a uma resposta protetora ao hospedeiro, enquanto que Shigella estaria "driblando" o sistema imune, além de provavelmente super-estimular o sistema imune adaptativo, fato que poderia levar a um agravamento da doença. As ações integradas das células Caco-2, células dendríticas e estímulos bacterianos foram estudadas em cocultura celular. Observou-se que EIEC e suas proteínas secretadas induzem a migração das CDs ao compartimento apical da co-cultura; nada foi observado quando o desafio se deu com Shigella...

Infección por Shigella spp. en el Hospital de Getafe entre 2001 y 2006 / Shigella spp. infections in Getafe Hospital between 2001 and 2006

Introducción: Shigella spp. es un patógeno que produce gastroenteritis aguda de forma frecuente en países en desarrollo, pero no tan habitual en España, donde se ha publicado que está disminuyendo su incidencia en los últimos años Objetivo: El objetivo de este estudio fue determinar cambios en la epidemiología de Shigella spp. en los últimos 5 años en la población infantil de Getafe, así como el tipo de Shigella spp. que produce enfermedad en el área 10 de Madrid (área que depende de nuestro hospital), la necesidad de ingreso, sus complicaciones y tratamiento. Método: Se llevó a cabo un estudio descriptivo, retrospectivo, basado en revisión de historias clínicas de los pacientes, menores de 15 años, afectados por shigellosis entre los años 2001 y 2006, que fueron identificados a partir del Servicio de Microbiología del Hospital Universitario de Getafe. Resultados: Se identificaron 19 pacientes, de los cuales sólo 4 precisaron ingreso. Las subespecies de Shigella spp. identificadas fueron S. sonnei y S. flexneri. La clínica más frecuente fue diarrea, que se acompañaba de vómitos, dolor abdominal tipo cólico y fiebre elevada. Sólo uno de los pacientes presentó deshidratación hiponatrémica como complicación. El tratamiento fue sintomático, salvo en los pacientes ingresados en los que se pautó fluidoterapia intravenosa y antibioterapia, con resolución de la enfermedad. Conclusión: En el estudio realizado parece existir un aumento de la incidencia de Shigella spp. en los últimos años en el área 10 de Madrid. Al no ser un patógeno frecuente en España, no existen muchos estudios, con lo que sería interesante realizar estudios prospectivos para confirmar este aumento de incidencia (AU)

Introduction: Shigella spp. is a bacterium that frequently causes diarrhoea in underdeveloped countries, but not so much in Spain, where it has been published that its incidence has decreased in the last few years. Objective: The aim of this study has been to asses changes in the epidemiology of Shigella spp. infection over the last 5 years in children of Getafe, as well as the subspecies of Shigella spp. that cause illness in this area (area 10, Madrid), the need for hospitalisation, the complications and the treatment. Method: A retrospective study was carried out, based on a review of the medical charts of children less than fifteen years old and had a diagnosis of Shigella spp. infection during 2000-2006. They were identified through the Getafe Hospital Microbiology Service. Results: Nineteen patients were identified, of which only four needed to be hospitalised. There were no differences between males and females. The Shigella spp. subspecies identified were S. sonnei and S. flexneri. The most frequent symptoms were vomiting, abdominal pain, diarrhoea, and fever. Only one had dehydration as a complication. The treatment was symptomatic, except in the four hospitalised patients, who required fluid therapy and antibiotics. The outcome was good in all patients. Conclusion: In this study, there appears to be an increase in the Shigella spp. incidence over the last few years in Area 10 of Madrid. Due to the fact that Shigella spp. is not a frequent bacterium in Spain, there are not enough studies on it, therefore it would be of interest to carry out prospective studies, in order to confirm this increase in incidence (AU)

Opciones de tratamiento en shigelosis / Treatment of shigellosis

La Shigella es una bacteria aeróbica Gram negativa que no fermenta la lactosa. Se considera la primera causa de disentería en nuestro país al igual que en todos los países subdesarrollados. Existen 4 especies que causan enfermedad gastrointestinal: S. dysenteriae (serogrupo A), S. fl exneri (serogrupo B), S. boydii (serogrupo C) y S. sonnei (serogrupo D). La S. fl exneri es la principal causa de shigellosis endémica en los países subdesarrollados. La S. dysenteriae es la que produce una potente citotoxina (toxina shiga), causa una enfermedad más severa, prolongada y fatal. Al mismo tiempo la resistencia antimicrobiana es más frecuente con esta especie.

Diarrea aguda: tratamiento nutricional / Acute diarrhea: nutrtional treatment

El tratamiento de la diarrea aguda consistirá básicamente en rehidratación oral si existiera deshidratación, realimentación precoz y excepcionalmente farmacológico. La rehidratación debe durar 4-6 horas, que se prolonga a 8-12 horas si la deshidratación es hipernatrémica, pasando posteriormente a la fase de mantenimiento. Las soluciones de rehidratación oral son las recomendadas, usándose en países en vías de desarrollo la solución de la OMS por las pérdidas importantes de sodio en las heces y soluciones con menor contenido de sodio en los países industrializados al ser las pérdidas de sodio menores. La realimentación debe ser lo mas precoz y equilibrada posible, recoméndandose la lactancia materna si es la forma de alimentación o la fórmula sin diluir si realiza lactancia artificial. No es aconsejable sistemáticamente las fórmulas sin lactosa. El uso de probióticos mejora el cuadro. No se precisa tratamiento farmacológico y los antibióticos sólo están indicados en pacientes inmunodeprimidos, cólera, lactantes menores de 3 meses con coprocultivos bacterianos positivos, enfermedad sistémica, infección por amebas, giardias, clostridium difficile y shigella que permanece sintomática (AU)

Brote de shigellosis en una escuela de educación básica / Shigella outbreak in an elementary school

Se analiza un brote de gastroenteritis por shigella sonnei, ocurrido en una escuela básica de una comuna de Santiago, en marzo de 1997. En esta escuela, con una matricula de 1470 niños entre 5 y 14 años de edad, 350 se beneficiaban con el programa de alimentación escolar (pae) y almorzaban en el establecimiento. Treinta y cinco de los 350 niños del pae presentaron simultáneamente gastroenteritis que motivó consulta en un servicio de emergencia, 2 de los cuales presentaron diarrea con sangre requiriendo hospitalización. Durante los cinco días posteriores se registraron 189 nuevos casos en la escuela. Frente a la notificación, se efectuó visita epidemiológica a la escuela, obteniéndose muestras de deposición para estudio de bacterias y virus enteropatógenos en 65 niños sintomáticos y en los tres manipuladores de alimentos. Se identificó s. sonnei en 20,5 porciento de los coprocultivos y todas las cepas tenían el mismo antibiotipo. La búsqueda de virus entéricos (rotavirus, calcivirus) dio resultados negativos. En los manipuladores de alimentos no se detectó enteropatógenos bacterianos ni virales. La presentación del brote plantea una toxiinfección por s. sonnei, iniciada probablemente por ingestión de alimentos (tasa de ataque primario 10 porciento) y luego transmisión persona a persona (tasa de ataque secundario 16,9 porciento) Para controlar el brote se reforzaron medidas de higiene personal y de saneamiento ambiental a través de educación a toda la comunidad escolar y el control sanitario del establecimiento. A partir del quinto día de iniciado el primer caso, se administró cotrimoxazol, durante cinco días, sólo a los casos sintomáticos. El brote se controló al noveno día

Papel de Shigella spp en un estudio controlado de enfermedad diarréica aguda

Para determinar el papel de shigella spp en un sector de la población infantil, se realizó un estudio descriptivo entre 250 pacientes pediátricos con síntomasn característicos de Enfermedad diarréica aguda (EDA) que consultaron al servicio de urgencias de la clínica del niño en la ciudad de Santafé de Bogotá en los meses de enero a abril de 1999. La información clínica, epidemiológica y de laboratorio, incluida en el estudio fue: edad, sexo, tiempo de evolución, sangre en la deposición, fiebre, vómito, grado de deshidratación, dolor abdominal, leucocitos en heces, parásitos y azúcares reductores. Las muestras de heces se incubaron durante 4-6 horas a 37 grados centigrados en un caldo de enriquecimiento para gram negativos (GN). A partir del caldo GN se realizaron subcultivos en los agares convencionales para bacterias entéricas; las colonias sospechosas se identificaron por pruebas bioquímicas y serológicas convencionales. A las cepas identificadas como Shigella se les realizaron pruebas de susceptibilidad antimicrobiana por el método de Bauer & Kirby. El procentaje de Shigella spp encontrado en el estudio fue del 4 por ciento. Un 50 pro ciento correspondió a S. sonnei, un 30 por ciento perteneció a S. dysenteriae y un 20 por ciento a S. flexneri. La suceptibilidad antimicrobiana de Shigella sppp demostró una alta resistencia a trimetoprin sulfametoxazole (90 por ciento),y una alta sensibilidad frente a ciprofloxacina (100 por ciento), imipemem (100 por ciento), ceftriaxona (90 por ciento) y cloramfenicol (70 por ciento). El estudio permite concluir que la incidencia de shigella entre los pacientes de la población pediátrica del centro estuadiado fue del 4 por ciento, con un predominio de shigella sonnei.

Multirresistencia antimicrobiana en cepas de shigella sp en una comuna semi rural del área norte de Santiago / Antimicrobial multiresistance of shigella sp strains in a semi rural community of north Santiago

Appropriate antimicrobial therapy shortens the duration of Shigellosis and significantly reduces the risk of transmission. Shigella strains resistant to common antimicrobials have increased during the past years, determining the need for a periodic surveillance, to guide effective therapy. Aim: To report the results of a surveillance program in a rural community near Santiago (Colina), for Shigella infections. Material and methods: Between 1995 and 1997, stool samples from 3,534 episodes of diarrhoea, that occurred in Colina, were obtained. Two hundred twenty six Shigella strains were isolated and studied for susceptibility to ampicilin (AM), amoxicillin/clavulanic acid (AMC), cotrimoxazole (STX), chloramphenicol (CAF), tetracycline (TET), furazolidine (FU), ciprofloxacine (CIPR), nalidixic acid (AC NAL), gentamycin (GENT) and cefotaxime (CFTX). Results: Shigella flexnerii represented 134 of 226 Shigella strains isolated. All strains were susceptible to CIPR, AC NAL, GENT and CFTX. Yearly variation of resistance patterns to other antimicrobials were observed for these strains. Resistance to AM varied from 56 to 76 percent, to AMC from 25 to 56 percent, to STX from 21 to 47 percent, to CAF from 36 to 39 percent, to TET from 44 to 78 percent and to FU from 9 to 18 percent. Overall resistance was higher during 1997. All 85 strains of S sonnei were susceptible to CIPR, AC NAL and CFTX. Resistance throughout the years varied from 56 to 88 percent for AM, from 0 to 28 percent for AMC, from 44 to 53 percent for STX, from 11 to 40 percent for CAF, from 11 to 42 percent for TET and from 5 to 11 percent for FU. Overall resistance was also higher during 1997, except for AM and STX. Seven S boydii strains were isolated, only during 1995. All seven were resistant to AM and TET and none were resistant to FU, CIPR, AC NAL and CFTX. One strain was resistant to AMC, STX and CAF. Conclusions: Antimicrobial resistance patterns of Shigella sp isolated in Colina have increased from 1995 to 1997, specially for commonly used antimicrobials. Resistance remains low for furazolidine and all strains remain susceptible to quinolones

Shiguelose: diagnóstico e tratamento / Shiguellosis: diagnosis and therapy

É uma doença diarréica aguda infecciosa mundialmente distribuída, causada por um bacilo gram-negativo da família das enterobactérias, transmitido por contato inter-humano, por água e alimentos contaminados, causando diarréia mucopiossanguinolenta, associada à febre, cólicas abdominais, urgência e tenesmo retal. O diagnóstico é baseado na história clínica e exame físico, sendo confirmado principalmente pela coprocultura e, mais raramente, pela hemocultura. Outros exames inespecíficos podem ser usados, como o hemograma e a análise do mucofecal. A sorologia e o PCR podem ser úteis, porém nem sempre facilmente disponíveis. O tratamento visa a correçÝo dos distúrbios hidroeletrolíticos já que a shiguelose costuma ser autolimitada, sendo porém, eventualmente necessário o uso de antimicrobianos. Quando a shiguela isolada se mostra sensível à ampicilina, esta droga tem sido utilizada como primeira escolha; entretanto, nÝo se isolando o agente causal, o sulfametoxazoltrimethopim pode ser indicado. atualmente, os melhores resultados (e com baixos ídices de resistência) têm sido obtidos com o uso das quinolonas, devendo, porém, ser usadas com critério devido ao aparecimento de cepas multirresistentes.

Características gerais de enteropatógenos bacterianos / Bacterial enteropathogens: general characteristics

Este trabalho realiza uma revisäo sobre os principais enteropatógenos bacterianos, enfocando principalmente aspectos de sistemática, fatores de virulência e algumas características fisiológicas