Acute diarrhea with blood: diagnosis and drug treatment / Diarreia aguda com sangue: diagnóstico e tratamento medicamentoso

Abstract Objective To restate the epidemiological importance of Shigella in acute diarrhea with blood, providing an overview of the treatment and stressing the need for the correct indication of antibiotic therapy. Sources of Data A search was carried out in the Medline and Scopus databases, in addition to the World Health Organization scientific documents and guidelines, identifying review articles and original articles considered relevant to substantiate the narrative review. Synthesis of Data Different pathogens have been associated with acute diarrhea with blood; Shigella was the most frequently identified. The manifestations of shigellosis in healthy individuals are usually of moderate intensity and disappear within a few days. There may be progression to overt dysentery with blood and mucus, lower abdominal pain, and tenesmus. Conventional bacterial stool culture is the gold standard for the etiological diagnosis; however, new molecular tests have been developed to allow the physician to initiate targeted antibacterial treatment, addressing a major current concern caused by the increasing resistance of Shigella. Prevention strategies include breastfeeding, hygiene measures, health education, water treatment, and the potential use of vaccines. Conclusions Acute diarrhea is an important cause of mortality in children under 5 years and shigellosis is the leading cause of acute diarrhea with blood worldwide. The current concern is the increase in microbial resistance to the recommended antibiotics, which brings an additional difficulty to therapeutic management. Although no vaccine is yet available against Shigella, several candidates are undergoing clinical trials, and this may be the most cost-effective preventative measure in future.

Resumo Objetivo Reiterar a importância epidemiológica da Shigella na diarreia aguda com sangue, fornecer uma visão geral do tratamento e ressaltar a necessidade da correta indicação da antibioticoterapia. Fontes dos dados Realizada pesquisa nos bancos de dados Medline e Scopus, além de documentos científicos e diretrizes da Organização Mundial da Saúde, com a identificação de artigos de revisão e artigos originais considerados relevantes para fundamentar a revisão do tipo narrativa. Síntese dos dados Diferentes patógenos têm sido associados à diarreia aguda com sangue, a Shigella é o mais frequente. As manifestações da shigelose em indivíduos saudáveis são geralmente de intensidade moderada e desaparecem em poucos dias. Pode haver progressão para disenteria franca com sangue e muco, dor em abdome inferior e tenesmo. A coprocultura bacteriana convencional é o padrão-ouro para o diagnóstico etiológico, porém novos testes moleculares foram desenvolvidos, os quais permitem ao médico iniciar tratamento antibacteriano direcionado, sanar uma grande preocupação atual, devido à crescente resistência da Shigella. Estratégias de prevenção incluem aleitamento, medidas de higiene, educação em saúde, tratamento da água e o potencial uso de vacinas. Conclusões A diarreia aguda é uma importante causa de mortalidade em crianças com menos de cinco anos e a shigelose é a principal causa de diarreia aguda com sangue em todo o mundo. A preocupação atual é o aumento da resistência microbiana aos antibióticos preconizados, o que traz uma dificuldade adicional ao manejo terapêutico. Embora ainda não exista vacina disponível para Shigella, várias candidatas estão em fase de testes clínicos, podem futuramente ser a medida preventiva mais custo-efetiva.

Bacteriemia por Shigella flexneri en dos lactantes / Shigella flexneri bacteremia in children: two case report and review of literature

Resumen Shigella spp. es el aislamiento microbiológico más frecuente en las diarreas bacterianas en Argentina. Clínicamente puede causar desde una diarrea acuosa hasta disentería. En forma infrecuente causa complicaciones extraintestinales, con una incidencia de bacteriemia desde 0,4 a 7,3%; asociado a factores de riesgo como niños menores de un año de edad e inmunodeficiencias, entre otros. Presentamos los casos clínicos de dos lactantes con bacteriemia por Shigella flexneri, que consultaron por fiebre y diarrea, uno de ellos con diagnóstico de inmunodeficiencia primaria.

Shigella spp. is the most frequent micro-biological isolation in bacterial diarrhea in Argentina. It causes a watery diarrhea or dysenteric disease. It rarely causes extraintestinal problems. It has an incidence of bacteremia of 0,4-7,3%, and its appearance compels us to look for associated risk factors, as children under one year of age and immunodeficiency, among others. We describe two children with Shigella flexneri bacteremia. They presented with fever and diarrhea. One of them had primary immune deficiency.

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)

Brote de shigelosis en la ciudad de Luján, Argentina / Shigelosis outbreak in the city of Lujan, Argentina

El objetivo del estudio fue describir un brote por Shigella sonnei ocurrido en julio de 2012 en Luján, Buenos Aires, Argentina. Estuvieron afectadas 5 personas que asistieron a una reunión familiar, donde consumieron una rosca vienesa de elaboración artesanal adquirida en un comercio. Todos presentaron fiebre, dolores articulares, escalofríos y diarrea no sanguinolenta con mucus. Se realizaron coprocultivos en los afectados y análisis microbiológicos de los ingredientes. Se aisló y caracterizó S.sonnei de todos los pacientes y de la crema de almendras empleada en la preparación de la rosca vienesa. A los aislamientos se les determinó el perfil de sensibilidad a los antimicrobianos y el genético por electroforesis en campo pulsado. Los resultados demostraron la relación genética de los aislamientos, y esto confirmó la ocurrencia de los casos por exposición a una misma fuente de infección, la crema de almendras. Al ser un ingrediente industrial, de improbable contaminación inicial, la crema de almendras podría haber sufrido una contaminación durante la manipulación en la panadería

The aim of this study was to describe an outbreak of Shigella sonnei that occurred in the city of Lujan, Buenos Aires, Argentina, in July 2012. Five individuals were affected after eating a handmade Viennese-style pastry at a family gathering. All of them presented with fever, joint pain, chills and non-bloody diarrhea containing mucus. Stool cultures were performed in all cases and the samples taken from the pastry ingredients were analyzed microbiologically. S.sonnei was isolated and identified in all the patients involved as well as in the almond cream filling. The isolates were analyzed for determining the antimicrobial susceptibility and genetic profiles by pulsed field gel electrophoresis (PFGE). The results showed the genetic relationship among the isolates, confirming that the cases occurred due to the patients' exposure to the same source of infection, i.e., the almond cream. Being the almond cream an industrially-manufactured ingredient, an initial contamination could have been unlikely; however contamination might have occurred as a result of manipulation in the bakery

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.

Bacteriemia por Shigellaflexneri serotipo 6 en pacientes con SIDA: Presentación de dos casos clínicos / Bacteraemia due to Shigella flexneri serotype 6 in two patients with AIDS

Infections due to Shigella usually remain localized to the digestive tract and are self-limited. Bacteremia is a potentially lethal complication that can occur in immunocompromised patients. We describe two episodes of bacteremia caused by Shigella in two adults with AIDS. In both patients, S. flexneri was recovered from stool and blood samples. The isolates belonged to serotype 6, were resistant only to trimethoprim-sulfamethoxazole and showed a similar band profile by pulsed-field gel electrophoresis. Patients received prolonged antimicrobial treatment with a favorable outcome. There were no cases of diarrhea in other individuals admitted to the emergency room. We hypothesized that patient No. 2 was infected at the hospital from patient No. 1. However, we could not establish the way of transmission. Although rare, it is important to take into account the possible occurrence of bacteremia due to Shigella or other bacterial enteropathogens in immunocompromised patients with diarrhea.

Las infecciones por Shigella spp., en general, permanecen localizadas en el tracto digestivo y tienen una evolución autolimitada. La bacteriemia es una complicación potencialmente letal que ocurre en pacientes con algún tipo de inmunocompromiso. Presentamos dos casos de bacteriemia causadas por Shigella en dos adultos con SIDA. En ambos pacientes, se recuperó Shigella flex-neri en muestras de deposiciones y sangre. Los aislados correspondieron al serotipo 6, fueron resistentes sólo a cotrimoxazol y mostraron un perfil de bandas similar por PFGE. Los pacientes recibieron tratamiento antimicrobiano prolongado y la evolución fue favorable. No se registraron otros casos de diarrea en individuos admitidos en el servicio de emergencia. La hipótesis fue que el paciente 2 adquirió la infección en el hospital a partir del paciente 1. Sin embargo, no pudimos establecer el modo de transmisión. Aunque poco frecuente, es importante tener presente la ocurrencia de bacteriemia por Shigella spp. o por otros enteropatógenos bacterianos en pacientes inmunocomprometidos con diarrea.

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.

The prevalence of swine enteropathogens in Brazilian grower and finish herds

Diarrhoea among growing and finishing pigs is an important problem in many herds. The prevalence of L. intracellularis, B. pilosicoli, B. hyodysenteriae, Salmonella spp., enterotoxigenic E. coli, Trichuris suis and the occurrence of mixed infection were investigated. Fecal samples for forty-six herds with diarrhea or a history of diarrhea were randomly collected in Minas Gerais state, Brazil. The enteric pathogens were detected by culture (E. coli and Salmonella sp.), PCR (L. intracellularis and Brachyspira spp.) and eggs counts (T. suis). The overall herd prevalence of L. intracellularis, Salmonella enterica serotype Typhimurium and enterotoxigenic E. coli were 19.56%, 6.52%, 10.86% respectively. Mixed infection was diagnosed in 30.43% of herds, and L. intracellularis and Salmonella enterica serotype Typhimurium are main pathogens association (10.87%). B. pilosicoli was diagnosed only in two herds, always associated with mixed infections. B. hyodysenteriae and T. suis were not demonstrated in any sample. These pathogens have been reported world-wide but studies regarding epidemiology in Brazil are few. This study contributes to establish of prevention programs for the control enteropathogens in grower finish herds in Brazil.

Surveillance of Antimicrobial Susceptibility Patterns among Shigella Species Isolated in China during the 7-Year Period of 2005-2011

BACKGROUND: Shigella is a frequent cause of bacterial dysentery in the developing world. Treatment with antibiotics is recommended for shigellosis, but the options are limited due to globally emerging resistance. This study was conducted to determine the frequency and pattern of antimicrobial susceptibility of Shigella in China. METHODS: We studied the antimicrobial resistance profiles of 308 Shigella spp. strains (260 S. flexneri, 40 S. sonnei, 5 S. boydii, and 3 S. dysenteriae) isolated from fecal samples of patients (age, from 3 months to 92 yr) presenting with diarrhea in different districts of Anhui, China. The antimicrobial resistance of strains was determined by the agar dilution method according to the CSLI guidelines. RESULTS: The most common serogroup in the Shigella isolates was S. flexneri (n=260, 84.4%), followed by S. sonnei (n=40, 13.0%). The highest resistance rate was found for nalidixic acid (96.4%), followed by ampicillin (93.2%), tetracycline (90.9%), and trimethoprim/sulfamethoxazole (80.8%). Among the isolates tested, 280 (91.0%) were multidrug resistant (resistant to > or =2 agents). The most common resistance pattern was the combination of ampicillin, tetracycline, and trimethoprim/sulfamethoxazole (70.8%). Resistance to ampicillin and tetracycline were more common among S. flexneri than among S. sonnei isolates. CONCLUSIONS: S. flexneri is predominant in Anhui, China, and its higher antimicrobial resistance rate compared with that of S. sonnei is a cause for concern. Continuous monitoring of resistance patterns is necessary to control the spread of resistance in Shigella. The recommendations for antimicrobial treatment must be updated regularly based on surveillance results.

CTX-M-55-Type Extended-Spectrum beta-lactamase-Producing Shigella sonnei Isolated from a Korean Patient Who Had Travelled to China

We report a case of CTX-M-55-type extended-spectrum beta-lactamase (ESBL)-producing Shigella sonnei infection in a 27-year-old Korean woman who had traveled to China. The patient was admitted to the hospital due to abdominal pain, watery diarrhea, and fever (39.3degrees C). S. sonnei was isolated from her stool specimens, and the pathogen was found to be resistant to cefotaxime due to CTX-M-55-type ESBL. Insertion sequence (IS)Ecp1 was found upstream of the blaCTX-M-55 gene. The blaCTX-M-55 gene was transferred from the S. sonnei isolate to an Escherichia coli J53 recipient by conjugation. Pulsed-field gel electrophoresis and Southern blotting revealed that the blaCTX-M-55 gene was located on a plasmid of approximately 130 kb.

Ceftriaxone resistant Shigella Flexneri, an emerging problem.

Shigellosis is a disease of public health importance in developing countries. It may cause self-limited diarrhea to severe dysentery. Emergence of multi drug resistant (MDR) strains is a growing concern globally. Ceftriaxone and ciprofloxacin are the drugs of choice for MDR cases. Here, we report a case of MDR Shigella flexneri from an immunocompromised patient. The strain was resistant to ceftriaxone [minimum inhibitory concentration (MIC) ≥ 64 μg/ml], limiting the treatment option. Simultaneously, the strain was also found to be resistant to ciprofloxacin (MIC ≥ 4 μg/ml). However, it was susceptible to ceftazidime (MIC 4 μg/ml). This is the first case of ceftriaxone resistant Shigella spp. reported from our hospital.

Etiology and the role of proctosigmoidoscopy in patients with acute bloody diarrheas

To find out the etiology of acute bloody diarrheas in patients admitted to a tertiary care hospital. This descriptive study was conducted in the department of medicine, Lady Reading hospital from 2005 to 2008. A total of 50 patients were studied, comprising of 35 males and 15 females. Mean age of the sample was 32.66 +/- 15.4 years]. Patients who presented with acute bloody diarrhea of between 3-30 days duration were studied. Patients who had history of recurrent bloody diarrhea were also included. Patients below 12 years, severely dehydrated and seriously ill were excluded. All patients underwent fibreoptic proctosigmoidoscopy and rectal biopsy. Amebic colitis was confirmed on stool examination for Trophozoites of Entameoba histolytica, typical proctosigmoidoscopic findings and response to anti-amebic drugs. Thirty-two patients [64%] were having new onset bloody diarrhea, while 18 patients [36%] were giving history of recurrent bloody diarrhea. All patients had evidence of Procto-colitis on fibreoptic sigmoidoscopy. The most common conditions were ulcerative colitis in 25 [50%], bacterial dysentery in 15 [30%] and Amebic proctocolitis in 7 [14%]. Findings on proctosigmoidoscopy were mucosal hyperemia [50%], bleeding points [38%], ulcers [44%], pus [20%], pseudo polyps [4%] and mass [4%]. Fibreoptic Proctosigmoidoscopy is a simple and easier procedure to diagnose different causes of acute bloody diarrhea and should be considered in all cases except in seriously ill and dehydrated patients. The common causes of acute bloody diarrhea in our community are bacterial proctocolitis, amebiasis and ulcerative colitis

Evaluación del nuevo medio CromoCen ECCS para la detección e identificación de bacterias enteropatógenas / Evaluation of the new CromoCen ECCS medium for detection and identification of enteropathogenic bacteria

Introducción: últimamente se ha desarrollado una variedad de medios de cultivo cromogénicos que constituyen herramientas útiles para el diagnóstico microbiológico. Objetivo: evaluar la eficacia de un nuevo medio cromogénico/fluorogénico, CromoCen ECCS, para la detección e identificación presuntiva de bacterias gramnegativas en el análisis de muestras fecales. Métodos: en el estudio de inclusividad se utilizaron 10 cultivos bacterianos de colecciones de referencia y 33 de origen clínico. Para el análisis de funcionalidad se emplearon 68 muestras fecales de un hospital pediátrico. Como referencia se emplearon los medios de cultivo agar SS y agar MacConkey. La identificación se realizó mediante pruebas bioquímicas y serológicas. Resultados: se evidenció que 92,8 de las cepas de Salmonella enterica, incluidos los serotipos Typhi y Paratyphi, desarrollaron colonias con características típicas en el medio de cultivo cromogénico. La sensibilidad, especificidad y exactitud diagnósticas estuvieron entre 97 y 100 para todos los grupos de interés, superando a los valores de los medios empleados en el diagnóstico de manera tradicional. En 14 muestras para coprocultivo se detectó el crecimiento de colonias de Salmonella enterica; de ellas 13 se confirmaron como positivas en la siembra directa en CromoCen ECCS, en un período de solo 24 h. No se observaron diferencias estadísticamente significativas para la proporción de muestras positivas detectadas en los medios CromoCen ECCS y agar SS. La única muestra positiva para Escherichia coli O157 a partir de las muestras fecales originales se detectó en el medio CromoCen ECCS y la infección causada por esta bacteria fue asociada con la de Salmonella. Conclusión: este medio resultó útil para la identificación presuntiva de bacterias gramnegativas, como Escherichia coli O157:H7, Salmonella y Shigella, porque se lograron obtener colonias con características culturales fácilmente diferenciadas.

Background: In last few years, a wide range of chromogenic cultural media has been developed to provide useful tools for microbiological diagnostic. Objective: To evaluate the efficacy of a new chromogenic/fluorogenic medium _ known as CromoCen ECCS_ for the detection and presumptive identification of Gram-negative bacteria by examining stool specimens. Methods: Ten bacterial cultures from the reference collections and thirty three other isolated clinical strains were used in the inclusivity study. For the performance analysis, 68 stool specimens from one pediatric hospital were used. As a reference, SS agar and MacConkey agar were used as cultural media, with further identification by biochemical and serological tests. Results: It was evidenced that 92.8 percent of Salmonella enterica strains, including Typhi and Paratyphi serotypes, developed typical colonies in the chromogenic cultural medium. Diagnostic sensitivity, specificity and efficiency ranged from 97 to 100 for all target groups, and were better than the values of traditional cultural media. Growth of Salmonella enterica colonies was detected in 14 samples for coproculture and 13 of them were confirmed to be positive in direct culture in CromoCen ECCS for 24 hours. There were not statistically significant differences between the ratio of Salmonella-positive samples detected on CromoCen ECCS and on SS agar. The only sample positive to Escherichia coli O157 was isolated on the CromoCen ECCS. The infection caused by this bacterium was associated with that of Salmonella. Conclusion: This cultural medium was useful for presumptive identification of Gram-negative bacteria such as Escherichia coli O157:H7, Salmonella and Shigella, because the developed colonies had easily distinguished cultural characteristics.

Epidemiología clínica y molecular de las infecciones por Shigella spp en niños de la Región Metropolitana durante el verano 2004-2005 / Shigella spp Infections In children living In the Metropolitan RegionChile, during summer of 2004-2005

Background: Shigella spp is a frequent cause of diarrhea in children. Antimicrobials decrease the duration of diarrhea and pathogen excretion. However, the increasing resistance limits their therapeutic value. Aim: To study Shigella serotype distribution in the Metropolitan Region in Chile, and its relationship with severity of disease, antimicrobial resistance pattern and clonality. Material and methods: During summer 2004-2005, stool samples from children with diarrhea were collected in Cary Blair transpon medium and cultured. Shigella isolates were serotyped using monoclonal and polyclonal commercial antibodies. In vitro activity of ampicillin, amoxicillin/clavulanic acid, chloramphenicol, cotrimoxazol, nalidixic acid, ciprofloxacin, ceftriaxone and azythromycin was determined by minimal inhibitory concentration (MIC). Clonality was studied by pulsed-field gel electrophoresis (PFGE) using Xbal as restriction enzyme. Results: One hundred thirty nine Shigella strains were isolated (77 S sonnei and 62 S flexneri). S sonnei and S flexneri 2a serotypes were responsible for 95 percent of episodes. Children aged 2-4 years, showed a greater incidence of Shigella infections and 77 percent of episodes were treated on an ambulatory basis. High resistance levels were observed for ampicillin, cotrimoxazole, amoxicillin-clavulanic acid and chloramphenicol (67 percent, 60 percent, 56 percent and 45 percent, respectively). We found 11 resistance patterns and 61,2 percent of strains were multiresistant. There were multiple clones without a strict relationship with resistance patterns. Conclusions: Shigella infections in Metropolitan Region in Chile are associated to a restricted number of serotypes, representing a clonal expansion associated to different antimicrobial resistant patterns.

Biodiagnóstico de las diarreas agudas bacterianas y virales / Biodiagnóstico of acute bacterial and viral diarrhea

El diagnóstico de las diarreas agudas bacterianas se realiza mediante la prescripción de coprocultivos típicos u orientados, realizados después del interrogatorio. Después del examen macroscópico y microscópico de las heces (diagnóstico de orientación), el cultivo puede poner en evidencia Salmonella, Shigella, Campylobacter o Yersinia, que serán siempre considerados como patógenos, mientras que, salvo excepción notable, la presencia de E. coli forma parte de la flora cólica comensal. En el niño, los agentes responsables de las gastroenteritis virales son, por orden devreciente de frecuencia, los rotavirus (sobre todo los del grupo A), calicivirus, astrovirus y adenovirus. En el diagnóstico virológico de rutina sólo se detectan rotavirus y adenovirus 40-41. Algunos coprocultivos se realizan en el curso de un cotexto epdemiológico-clínico particular en búsqueda de bacterias enteropatógenas como Vibrio cholerae, Clostridium difficile o E. Coli enterohemorrágico. Este patotipo de E. Coli puede ser responsable del síndrome hemolítico y urémico ligado a la producción de toxinas. Su responsabilidad a menudo se establece por cultivo después de serotipado, por detección de las toxinas producidas o más raramente por métodos serológicos. La diarrea aguda es un fenómeno patológico definido según la OMS por la emisión de al menos tres heces líquidas o blandas al fía con menos de 14 días de antelación. Puede tener diferentes orígene, infecciosos o no. Cuando el origen de la diarrea aguda es infeccioso puede ser bacteriana, viral o parasitaria. Es frecuente en el niño,en el que representa una causa mayor de morbilidad y mortalidad en el mundo. En Frencia, cerca de tres millones de pacientes consultan por una diarrea aguda y sólo del 3 al 4% de estas consultas originan la prescripción de un coprocultivo (1). Es importante para el microbiólogo conseguir informació de los signos clínicos (dolores abdominales, fiebre, aspecto de las heces) y del contexto epidemiológico...

The 23S rRNA gene PCR-RFLP used for characterization of porcine intestinal spirochete isolates

Using three reference strains of Brachyspira hyodysenteriae (B204, B234, B169), one B. pilosicoli (P43/6/78), one B. murdochii (56-150), one B. intermedia (PWS/A), one B. innocens (B256) and ten Korean isolates, PCR-RFLP analysis of DNA encoding 23S rRNA was performed to establish a rapid and accurate method for characterizing porcine intestinal spirochetes. Consequently, B. hyodysenteriae and B. pilosicoli revealed different restriction patterns; however, the other three species shared the same pattern. These findings are not consistent with a prior report. Differences in 23S rRNA gene sequences, between two B. murdochii strains, 56-150 and 155-20, were observed. These results indicate that 23S rRNA PCR-RFLP could be used as an identification method for pathogenic Brachyspira spp. (B. hyodysenteriae and B. pilosicoli) as well as an epidemiological tool for characterizing spirochetes isolated from swine.

Análisis de un brote de diarrea aguda / Analysis of an outbreak of an acute diarrhoea

Durante los meses de mayo a julio de 1998, se presentaron en la localidad de Río Pico, de la Provincia del Chubut, un número significativamente elevado de pacientes con enfermedad diarreica y síntomas sistémicos. Se realizó un trabajo con los profesionales del Hospital Rural de Río Pico, del Hospital Zonal de Esquel, del Area Prográmatica Zona Noroeste del Chubut y del Departamento Zonal de Medio Ambiente del Chubut ante la sospecha de la existencia de un brote de disentería. Se elaboró una ficha donde se registraron datos de 82 de los 120 casos notificados que permitiera establecer el patrón epidemiológico del brote. Se practicaron coprocultivos de casos índices, se hizo búsqueda de portación de manipuladores de alimentos y se tomaron muestras de agua de la localidad. Se identificó como agente etiólogico Shigella Sonnei. El análisis de estas variables condujo a tomar medidas que incluyeron la suspensión de las actividades escolares, tratamiento precoz con antimicrobianos y difusión por los medios de prensa locales de medidas higiénico-dietéticas. Estas medidas fueron dirigidas a controlar la transmisión persona a persona principal mecanismo involucrado en la diseminación de las disentería bacilares. Con su implementación disminuyó significativamnente la frecuencia de los casos. El presente trabajo tiene como objetivo alertar sobre la necesidad de implementar correctamente los mecanismos de vigilancia y mostrar una forma de analizar un brote adaptando el estudio al terreno