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.

Antisuero AA479: nuevo reactivo para la serotipificación de variantes atípicas se Shigella flexneri / AA479 antiserum: new reagent for the serotype characterization of atypical variants of Shigella flexneri

Shigella flexneri is divided into 13 serotypes based on the combination of antigenic determinants present in the O-antigen. A new O-antigen modification with phosphoethanolamine has been identified. The presence of this antigenic determinant (called E1037) is recognized by monoclonal antibody MASF IV-1. Given the increasing incidence of these new variants and the difficulty in supplying the monoclonal antibody to our country, we produced a polyclonal antiserum (AA479) through immunization with a S. flexneri Xv strain. The antiserum specificity was assessed by slide agglutination against isolates from clinical cases and a culture collection representing all Shigella serotypes. The results obtained demonstrated a 100% correlation between AA479 absorbed antiserum and monoclonal antibody MASF IV-1. The availability of AA479 antiserum in every public hospital in Argentina will allow us to identify atypical S. flexneri isolates in order to strengthen Shigella surveillance in our country and to compare with global epidemiological dat

Shigella flexneri se divide en al menos 13 serotipos sobre la base de la combinación de determinantes antigénicos presentes en el antígeno O. Se identificó una nueva modificación del antígeno O con fosfoetanolamina. La presencia de este determinante antigénico (denominado E1037) es reconocida por el anticuerpo monoclonal MASF IV-1. Teniendo en cuenta la incidencia creciente de estas nuevas variantes y la dificultad en la provisión del anticuerpo monoclonal para nuestro país, se elaboró un antisuero de tipo policlonal (AA479) mediante la inmunización con un cultivo de S. flexneri Xv. La especificidad del antisuero se evaluó por aglutinación en lámina con aislamientos clínicos y cultivos de colección, con lo que quedaron representados todos los serotipos de Shigella. Los resultados obtenidos demostraron una correlación del 100% entre el antisuero AA479 absorbido y el anticuerpo monoclonal MASF IV-1. La disponibilidad del antisuero AA479 en todos los hospitales públicos de Argentina permitirá identificar los aislamientos atípicos de S. flexneri; de esta forma se podrá fortalecer la vigilancia de Shigella en nuestro país y comparar con los datos epidemiológicos a nivel global

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.

Frequency of Shigella flexneri serotypes isolated in the state of Pará, Brazil (1979-2009) / Frequência de sorotipos de Shigella flexneri isoladas no estado do Pará, Brasil (1979-2009)

O gênero Shigella tem sido uma das causas mais comuns de diarréia em países pouco desenvolvidos, sendo responsável pela mortalidade e / ou morbidade em população de alto risco, como crianças menores de cinco anos e idosos. Este estudo, realizado no Instituto Evandro Chagas (IEC) , Estadodo Pará, Brasil, no período de 1979 a 2009, teve como objetivo avaliar a frequência de espécies e sorotipos de 122 isolados de Shigella spp. provenientes de pacientes com diarréia aguda. Os isolados bacterianos foram identificados por meios de culturas seletivos e indicadores e testes bioquímicos. Todos os isolados foram identificados quanto ao sorogrupo e sorotipo por meio da soroaglutinaçãoem lâmina. Os sorogrupos mais frequentemente encontrados foram S. flexneri (66,4por cento) e S. sonnei(32,8por cento). O sorotipo de S. flexneri mais frequente foi o 2a (54,3por cento) seguido de 1b (17,2por cento). A maioria dos pacientes tinham idade entre 0 a 5 anos (44,6por cento), dos quais 38,2por cento apresentaram S. flexneri e 47,5por cento S. sonnei. Pacientes com idade superior a 18 anos representaram 39,2por cento das infecções, sendo 37,0por cento casos de S. flexneri, 32,5por cento de S. sonnei e um isolado de S. boydii. Esses resultados reforçam a necessidade de uma vigilância epidemiológica contínua no Estado do Pará.

Surveillance of antibiotic susceptibility pattern among shigella flexneri strain isolated in Nagpur district during three years period, January 2009-January 2012.

Objective : In the few cases of childhood dirrhea that require the antimicrobial therapy, the correct choice of the drug depends on detailed previous knowledge of local strains and pattern of antimicrobial resistance. Shigellosis is one of the most improtant examples of this group of intestinal infections. In order to establish such parameters in Nagpur city, this study was carried out to determine the antimcrobial resistance profile of Shigella flexneri isolated from patients suffering from diahhrea admitted to Various hoapitals in Nagpur district, India. Materials and Methods: The study included 110 stool samples collected from patients during the 3 year period. All the isolates were characterized and confirmed by VITEK® 2 GN ID cards and antimicrobial susceptibility was tested by VITEK® 2 AST test cards. Results: We received 73 positive cultures of S. flexneri out of 110 stool samples during three year periods of January 2009 to January 2012. S. flexneri strains presented a high resistance rate to Ampicillin (100%), Chloramphenicol (76.71%), Trimethoprime-sulfamethaxazole (TMP-SMZ) (68.49%) and low resistance to third- and fourth-generation Cephalosporin. None of the isolates was found to be resistant to Ciprofloxacin (MIC ≥ 4), Norfloxacin (MIC ≥12), and Nalidixic acid (MIC ≥30). Conclusion: Our results provide data on antimicrobial resistance to choose a proper antibiotic for the treatment of Shigellosis in our country. According to current findings, Quinolones and Cephalosporins are the drug of choice for the diarrheic patients. In conclusion, systematic monitoring is needed to identify changes in the antimicrobial resistance.

Epidemiological characterization of resistance and PCR typing of Shigella flexneri and Shigella sonnei strains isolated from bacillary dysentery cases in Southeast Brazil

Shigella spp are Gram-negative, anaerobic facultative, non-motile, and non-sporulated bacilli of the Enterobacteriaceae family responsible for "Shigellosis" or bacillary dysentery, an important cause of worldwide morbidity and mortality. However, despite this, there are very few epidemiological studies about this bacterium in Brazil. We studied the antibiotic resistance profiles and the clonal structure of 60 Shigella strains (30 S. flexneri and 30 S. sonnei) isolated from shigellosis cases in different cities within the metropolitan area of Campinas, State of São Paulo, Brazil. We used the following well-characterized molecular techniques: enterobacterial repetitive intergenic consensus, repetitive extragenic palindromic, and double-repetitive element-polymerase chain reaction to characterize the bacteria. Also, the antibiotic resistance of the strains was determined by the diffusion disk method. Many strains of S. flexneri and S. sonnei were found to be multi-resistant. S. flexneri strains were resistant to ampicillin in 83.3 percent of cases, chloramphenicol in 70.0 percent, streptomycin in 86.7 percent, sulfamethoxazole in 80.0 percent, and tetracycline in 80.0 percent, while a smaller number of strains were resistant to cephalothin (3.3 percent) and sulfazotrim (10.0 percent). S. sonnei strains were mainly resistant to sulfamethoxazole (100.0 percent) and tetracycline (96.7 percent) and, to a lesser extent, to ampicillin (6.7 percent) and streptomycin (26.7 percent). Polymerase chain reaction-based typing supported the existence of specific clones responsible for the shigellosis cases in the different cities and there was evidence of transmission between cities. This clonal structure would probably be the result of selection for virulence and resistance phenotypes. These data indicate that the human sanitary conditions of the cities investigated should be improved.

Risk factors for mortality due to shigellosis: a case-control study among severely-malnourished children in Bangladesh.

To determine the risk factors for death of severely-malnourished Bangladeshi children with shigellosis, a case-control study was conducted at the Clinical Research and Service Centre of ICDDR,B: Centre for Health and Population Research in Dhaka, Bangladesh. One hundred severely-malnourished children (weight-for-age <60% of median of the National Center for Health Statistics), with a positive stool culture for Shigella dysenteriae type 1 or S. flexneri, who died during hospitalization, were compared with another 100 similar children (weight-for-age <60% and with S. dysenteriae type 1 or S. flexneri-associated infection) discharged alive. Children aged less than four years were admitted during December 1993-January 1999. The median age of the cases who died or recovered was 9 months and 12 months respectively. Bronchopneumonia, abdominal distension, absent or sluggish bowel sound, clinical anaemia, altered consciousness, hypothermia, clinical sepsis, low or imperceptible pulse, dehydration, hypoglycaemia, high creatinine, and hyperkalaemia were all significantly more frequent in cases than in controls. In multivariate regression analysis, altered consciousness (odds ratio [OR]=2.6, 95% confidence interval [CI] 1.0-6.8), hypoglycaemia (blood glucose <3 mmol/L (OR=7.8, 95% CI 2.9-19.6), hypothermia (temperature <36 degrees C) (OR=5.7, 95% CI 1.5-22.1), and bronchopneumonia (OR=2.5, 95% CI 1.1-5.5) were identified as significant risk factors for mortality. Severely-malnourished children with shigellosis having hypoglycaemia, hypothermia, altered consciousness and/or bronchopneumonia were at high risk of death. Based on the findings, the study recommends that early diagnosis of shigellosis in severely-malnourished children and assertive therapy for proper management to prevent development of hypothermia, hypoglycaemia, bronchopneumonia, or altered consciousness and its immediate treatment are likely to reduce Shigella-related mortality in severely-malnourished children.

Experimental study on the antibacterial effect of origanum volatile oil on dysentery bacilli in vivo and in vitro / 华中科技大学学报（医学）（英德文版）

To observe the germistatic and germicidal effects of origanum volatile oil (OVI) on the dysentery bacteria, the abdominal cavity of mice was infected with Shigella sonne (Sh. sonnei) and Shigella flexneri (Sh. flexneri) F2a. After OVI was given to the mice via gastric lavage, the effects of OVI on the infected mice were observed. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) for dysentery bacteria were determined in vitro. The results showed that origanum volatile oil showed obvious protective effect on mice infected with Sh. sonnei and Sh. flexneri F2a and it had germistatic and germicidal effects on dysentry bacteria. We are led to conclude that origanum volatile oil is an effective medicine against the infection of dysentery bacteria.

Validation of salmonellosis and shigellosis diagnostic test kits at a provincial hospital in Thailand.

Rapid Diagnosis of salmonellosis and shigellosis was performed using six different diagnostic test kits which recently have been made available commercially. They were Salmo-Dot, Typhi-Dot, Shigel Dot A, B, C, and D test kits for detection of Salmonella spp., group D salmonellae, and groups A, B, C, and D Shigella spp., respectively. The principle of all test kits is a membrane (dot) ELISA using specific monoclonal antibodies to the respective pathogens as the detection reagents. The present study was designed to validate the accuracy of the test kits, at a laboratory in a provincial hospital in Thailand, in comparison with the conventional bacterial culture method alone or with the combined results of the culture and the Western blot analysis (WB) for detecting the respective bacterial lipopolysacchharides (LPS) in specimens. Five hundred rectal swab samples of patients with diarrhea who seeked treatment at the hospital, were evaluated. The diagnostic accuracy of the Salmo-Dot was 91.0% when compared with the conventional bacterial culture method alone but was 100.0% in comparison with the combined results of the culture and the WB. The Typhi-Dot and the Shigel-Dot A, B, C, and D showed 100%, 99.2%, 95.0%, 94.0% and 96.4%, respectively when compared with the culture alone and all were 100% in comparison with the combination of the results of the bacterial culture and the WB. The Shigel-Dot A revealed antigen of type 1 Shigella dysenteriae in several specimens in which the bacteria could not be recovered by the culture method. This difference is important as type 1 Shigella dysenteriae have high epidemic potential and often cause severe morbidity. Unawareness of their presence by the conventional culture may have great impact on disease surveillance for public health. The pathogen detection using the six diagnostic test kits is sensitive, specific, rapid, and relatively simple and less expensive. Several specimens can be tested at the same time without much increase in turn around time. Moreover, these kits produce no contaminated waste as compared with the bacterial culture method. The test kits should be used for rapid screening of specimens of patients with diarrhea especially in areas where culture facilities are inadequate.

Patrones de sensibilidad in vitro y comportamiento clínico de shigella / Susceptibility patterns and clinical presentation of shigella

Shigella mantiene un importante lugar como causa de diarrea en niños con aumento de su resistencia antimicrobiana en los últimos años, lo que dificulta la elección de terapia empírica en cuadros disentéricos. Se estudió la susceptibilidad antimicrobiana in vitro a 163 cepas aisladas entre 1997 y 1999. S. sonnei representó el 63 por ciento de las cepas aisladas. Se observó aumento en los patrones de resistencia de Shigella a los antimicrobianos tradicionales. La resistencia global de las cepas alcanzó a 95 por ciento para ampicilina, 84 por ciento para cloranfenicol, 43,6 por ciento para cotrimoxazol y 3,7 por ciento para furazolidona; no hubo resistencia a ciprofloxacina. De 57 niños hospitalizados por shigelosis, 82,5 por ciento tenían sobre 2 años de edad. Todos presentaron fiebre, 56 por ciento disentería y 8,8 por ciento convulsiones. Seis pacientes con evolución tórpida recibieron ciprofloxacina con éxito clínico. Ciprofloxacina representa una alternativa a evaluar como terapia empírica en niños con disentería de causa bacteriana. Es necesario mantener vigilancia local en la susceptibilidad antimicrobiana de Shigella a fin de guiar su terapia específica

Vigilancia de la resistencia a los antibacterianos en Argentina: programa WHONET, 1995-1996 / Monitoring antimicrobial resistance in Argentina: The WHONET program, 1995­1996

La Organización Mundial de la Salud ha puesto en marcha un programa para la vigilancia de la resistencia a los antibacterianos, denominado WHONET, que se desarrolló en Argentina mediante una red de 23 laboratorios de instituciones hospitalarias públicas y privadas sometidos a programas nacionales e internacionales de control de calidad. Entre enero de 1995 y diciembre de 1996 se determinó por el método de difusión en agar la sensibilidad a los antibacterianos de 16.073 aislados clínicos consecutivos, siguiendo las recomendaciones del Comité Nacional de Estándares para Laboratorios Clínicos (National Committee for Clinical Laboratory Standards: NCCLS) de los Estados Unidos de América. Más de la mitad de los aislados urinarios de Escherichia coli fueron resistentes a la ampicilina, y más de 30 por ciento a la trimetoprima-sulfametoxazol. Cuando se comparó la sensibilidad de los aislados urinarios de pacientes ambulatorios y hospitalizados, se observó una marcada diferencia en los perfiles de actividad (porcentaje de microorganismos resistentes aislados en pacientes hospitalizados frente a pacientes ambulatorios) de la gentamicina (8 por ciento frente a 2 por ciento), la norfloxacina (6 por ciento frente a 2 por ciento) y las cefalosporinas de tercera generación (18 por ciento frente a 10 por ciento). Los aislados de Klebsiella pneumoniae recuperados de hemocultivos presentaron resistencia a las cefalosporinas de tercera generación y a la gentamicina en 71 y 60 por ciento de los casos, respectivamente. La proporción de Staphylococcus aureus resistentes a la oxacilina fue de 39 por ciento. Cerca de la mitad de los aislados de Enterococcus spp. presentaron resistencia de alto nivel a los aminoglucósidos, pero no se detectó resistencia los glicopéptidos. En nuestro medio, la ampicilina y la trimetoprima-sulfametoxazol no fueron apropiadas para el tratamiento de las diarreas; Shigella flexneri presentó mayor porcentaje de aislados resitentes a ambos fármacos (87 y 74 por ciento, respectivamente) que Shigella sonnei (47 y 71 por ciento, respectivamente). Se detectó resistencia a las cefalosporinas de tercera generación en 40 por ciento de los aislados de Salmonella spp. recuperados en hospitales pediátricos. En casos de meningitis bacteriana, las tasas de resistencia de Streptococcus pneumoniae a la penicilina (18 por ciento) y de Haemophilus influenzae a la ampicilina (19 por ciento) se situaron en el rango intermedio de las descritas en países

The World Health Organization has implemented a surveillance program for antimicrobial resistance that is known as WHONET. In Argentina the program was developed through a network of 23 public and private hospitals that participate in national and international quality-control programs. Between January 1995 and December 1996, the antimicrobial susceptibility of 16 073 consecutive clinical isolates was determined, using the recommended standards of the National Committee for Clinical Laboratory Standards of the United States of America. More than half of the Escherichia coli urinary isolates were resistant to ampicillin and more than 30% to trimethoprim/ sulfamethoxazole (SXT). When the percentage of resistant isolates from outpatients (OPs) was compared to that observed in hospitalized patients (HPs), a marked difference in antimicrobial activity was noted in the case of gentamicin (2% from OPs resistant vs. 8% from HPs resistant), norfloxacin (2% vs. 6%), and third-generation cephalosporins (7% vs. 15%). Of the Klebsiella pneumoniae isolates recovered from blood cultures, 71% and 60% showed resistance to third-generation cephalosporins and to gentamicin, respectively. The overall rate of oxacillin resistance in Staphylococcus aureus was 39%. Around half of the Enterococcus spp. isolates showed high resistance to aminoglycosides, but resistance to glycopeptides was not found. In Argentina, ampicillin and SXT were not suitable for treating diarrhea. Shigella flexneri had a higher number of isolates resistant to both of those drugs (87% and 74%, respectively) than Sh. sonnei did (47% and 71%, respectively). About 40% of the Salmonella spp. isolated in pediatric hospitals were resistant to third-generation cephalosporins. When microorganisms causing bacterial meningitis were examined, Streptococcus pneumoniae showed a resistance rate of 18% to penicillin and Haemophilus influenzae a resistance rate of 19% to ampicillin. These rates are within the intermediate range reported for other countries of the Americas and for Europe

Frecuencia y biodiversidad de algunas bacterias enteropatógenas aisladas en niños con síndrome diarreico agudo / Frequency and biodiversity of some enteropathogenic bacteria recovered from children with acute diarrheic syndrome

El estudio etiológico de la diarrea aguda en el niño se ve limitado por las técnicas actualmente disponibles con fines clínicos. La aplicación de técnicas de biología molecular en el análisis de deposiciones permite incrementar la detección de enteropatógenos y una caracterización fenotípica más acabada de las cepas aisladas permite describir mejor su diversidad y caracterizar epidemiológicamente los episodios observados en cada temporada estival. En un estudio piloto efectuado en la ciudad de Concepción, se aplicaron en el estudio etiológico de la diarrea en niños entre 0 y 4 años de edad consultantes en un servicio de urgencia, las técnicas convencionales de cultivo e identificación por pruebas bioquímicas según Edwards y Ewing, la búsqueda de genes de virulencia de Escherichia coli enterohemorrágica más el análisis de serotipo, biotipo, antibiotipo y perfil plasmidial de las cepas enteropatógenas aisladas. En 32 (25,3 por ciento) de 127 niños con diarrea de edad entre 5 meses y 4 años de detectó la frecuencia de los siguientes enteropatógenos: Shigella sonnei 13,4 por ciento Shigella flexneri 6,3 por ciento, Yersinia enterocolitica 2,4 por ciento, Shigella boydii 0,8 por ciento, Salmonella typhimurium 1,6 por ciento y Salmonella hadar 0,8 por ciento. La frecuencia de aislamiento aumentó en relación al aumento de la edad desde 0 por ciento en el grupo etario de 4 a 5 meses, 6,3 por ciento en el de 6 a 11 meses, 33,1 por ciento en el de 12 a 23 meses, hasta 68,7 por ciento en el grupo de 24 a 47 meses. Shigella spp. fueron las de mayor frecuencia relativa de aislamiento con 81,1 por ciento. El rendimiento de las determinaciones feno y genotípicas para estudio de biodiversidad fue variable en las especies. Las 8 cepas de S. flexneri se diferenciaron en 6 grupos en base a 3 serotipos, 5 antibiotipos y 5 perfiles plasmidiales. Las 17 cepas de S. sonnei se discriminaron en 11 grupos determinados preferentemente por los patrones plasmidiales. La amplificación aleatoria mediante RAPD en S. flexneri y S. sonnei no aportó mayor grado de biodiversidad que la establecida por las otras determinaciones. El antibiotipo y perfil plasmidial fueron útiles en discriminar en 2 grupos las 3 cepas de Y. enterocolitica, marcadores que además permitieron sugerir que las S. typhimurium aisladas serían una misma cepa

Septicemia por Shigella flexneri / Septicaemia by Shigella flexneri

Se reporta el primer caso de aislamiento de Shigella flexneri en sangre, en Costa Rica; se hace referencia de lo poco usual de este hallazgo y énfasis en la resistencia de esta bacteria a los antibióticos orales convencionales, y la necesidad de tratar este caso con una cefalosporina de tercera generación.

Aislamientos de Shigella y Salmonella durante el período 1990-1994 / Isolation of Shigella and Salmonella during the period 1990-1994

En el siguiente trabajo se comunican los aislamientos de Shigella y Salmonela en pacientes con diarreas agudas que fueron atendidos en el Hospital de Niños Ricardo Gutierrez de la ciudad de Santa Fe en el período 1990-1994. Shigella prevaleció en cada uno de los años estudiados con respecto a Salmonella, y el serogrupo predominante fue flexneri. La recuperación de Salmonella fue similar en cada año, debiéndose destacar un brote intrahospitalario a Salmonella typhimurium. Es importante conocer los agentes más frecuentes para que las medidas de control sean dirigidas y permitan orientar investigaciones futuras relacionadas con las enfermedades diarreicas

Diarreia causada por Shigella: aspectos clinicos e terapeuticos / Diarrhea caused by Shigella: clinical and therapeutical aspects

Os autores estudaram diarreias graves causadas por Shigella sp que foram atendidas no Servico de Emergencias do Hospital Universtario da USP durante tres anos. Esse agente foi isolado de 65 casos de diarreia aguda que corresponderam a 3,1 por cento dos casos graves e 22,3 por cento dos quadros clinicos de disenteria. A S.flexneri foi a mais isolada, seguida pela S.sonnei, na proporcao de 3:1...

Shigella isolates in stool.

A total of 447 Shigella strains were isolated from stool samples during 1989-1991. Of these 270 (60%) were from children. Among the different species and serotypes Sh. flexneri 60 (13.4%) and Sh. sonnei Phage 139 (65%) were the most frequently isolated strains. 154 (34.4%) strains were resistant to three and 179 (40%) to more than three antibiotics. Some strains of Shigella were found to be resistant to furazolidine and neomycin.

Diarréia crônica e infecçöes repetidas em adulto / Chronic diarrhea and repeated infections in an adult

Um caso de infecçäo por Shigella flexneri em uma mulher de 34 anos de idade com hipogamaglobulinemia e diarréia é apresentado; o problema diagnóstico representado por diarréia no paciente com hipogamaglobulinemia é discutido. A revisäo de 7 outros pacientes com hipogamaglobulinemia tratados no HCRP é apresentado e é enfatizado que vários agentes patogênicos podem causar diarréia nesses pacientes

Shigellosis in children: a prospective hospital based study.

From 1985 to 1988, fecal samples of 950 hospitalized children suffering from diarrhea or dysentery were screened for Shigella species using standard methods. Shigella species were isolated as sole pathogen from 192 (20.2%) cases and S. flexneri type 2 was the predominant serotype. Shigella infection was prevalent throughout the year with high isolation rate during the summer and early monsoon months. Shigella strains isolated during the period were resistant to most of the commonly used drugs for the treatment of shigellosis. Nearly 16% of the Shigella strains were also resistant to nalidixic acid. Presence of blood and mucus in stools (dysentery) was the common clinical presentation of shigellosis cases. Malnutrition was associated with longer duration of illness. High cases fatality rate (16.7%) was observed among hospitalized children infected with Shigella.

Comparación de tres métodos empleados para el control de calidad de medios de cultivo sólido / Comparison of three methods employed in tue quality control of solid culture media

El objetivo de este estudio fue comparar tres métodos utilizados en el control de calidad de medios de cultivo: a)el método original de Miles-Mirsa; b)el ecométrico y c)el método de estrías. Para comparar estos métodos, se evaluaron la productividad (crecimiento de un microorganismo que habitualmente se desarrolla en un medio de cultivo) y la selectividad (supresión del crecimiento de un microorganismo, que se espera sea inhibido en un medio de cultivo) de seis medios sólidos de cultivo usados para el aislamiento de Salmonella spp. y Shigella spp. Los resultados que se obtuvieron al comparar los 3 métodos, mediante la prueba de Chi2, reflejan que existe diferencia significativa (p<0.05) entre el método de estrías y los otros 2 en lo referente a la productividad, no existiendo diferencia significativa entre los 3 métodos, en cuanto a selectividad. De los 3 métodos ensayados, el ecométrico resultó el de más fácil y rápida ejecución