A persistência intracelular de Escherichia coli enteroagregativa induz a secreção de citocinas pró-inflamatórias em células epiteliais intestinais T84 / Intracellular persistence of enteroaggregative escherichia coli induces a proinflammatory cytokines secretion in intestinal epithelial t84 cells

ABSTRACT BACKGROUND: The competence of enteroaggregative Escherichia coli (EAEC) to adhere to the intestinal epithelium of the host is a key role to the colonization and disease development. The virulence genes are crucial for EAEC pathogenicity during adherence, internalization and persistence in the host. The overwhelming majority of antigen encounters in a host occurs on the intestine surface, which is considered a part of innate mucosal immunity. Intestinal epithelial cells (IECs) can be activated by microorganisms and induce an immune response. OBJECTIVE: The present study investigated the interaction of invasive EAEC strains with T84 intestinal epithelial cell line in respect to bacterial invasiveness, persistence and cytokines production. METHODS: We evaluated intracellular persistence of invasive EAEC strains (H92/3, I49/3 and the prototype 042) and production of cytokines by sandwich ELISA in T84 cells upon 24 hours of infection. RESULTS: The survival rates of the prototype 042 was 0.5x103 CFU/mL while survival of I49/3 and H92/3 reached 3.2x103 CFU/mL and 1.4x103 CFU/mL, respectively. Infection with all EAEC strains tested induced significant amounts of IL-8, IL-6 and TNF-α compared to uninfected T84 cells. CONCLUSION: These data showed that infection by invasive EAEC induce a proinflammatory immune response in intestinal epithelial T84 cells.

RESUMO CONTEXTO: A competência de Escherichia coli enteroagregativa (EAEC) para aderir ao epitélio intestinal do hospedeiro é um papel fundamental para a colonização e o desenvolvimento da doença. Os genes de virulência são cruciais para a patogenicidade de EAEC durante a aderência, a internalização e a persistência no hospedeiro. A grande maioria dos encontros de antígenos em um hospedeiro ocorre na superfície do intestino, que é considerada parte da imunidade inata da mucosa. As células epiteliais intestinais (IECs) podem ser ativadas por micro-organismos e induzir uma resposta imune. OBJETIVO: O presente estudo investigou a interação de cepas invasoras de EAEC com a linhagem celular epitelial intestinal T84 em relação a invasão bacteriana, a persistência e a produção de citocinas. MÉTODOS: Avaliamos a persistência intracelular de cepas invasoras de EAEC (H92/3, I49/3 e o protótipo 042) e a produção de citocinas por ELISA "sanduíche" em células T84 após 24 horas de infecção. RESULTADOS: As taxas de sobrevivência da cepa protótipo 042 foi de 0,5x103 UFC/mL, enquanto a sobrevivência de I49/3 e H92/3 atingiu 3,2x103 UFC/mL e 1,4x103 UFC/mL, respectivamente. A infecção com todas as cepas EAEC testadas induziu quantidades significativas de IL-8, IL-6 e TNF-α em comparação com células T84 não infectadas. CONCLUSÃO: Estes dados mostraram que a infecção por EAEC invasoras induzem uma resposta imune pró-inflamatória em células epiteliais intestinais T84.

Escherichia coli enteroagregativa como agente provocador de diarreia persistente: modelo experimental utilizando microscopia óptica de luz / Enteroaggregative Escherichia coli as a cause of persistent diarrhea: an experimental model using light microscopy

OBJETIVO: Avaliar interações de amostras de Escherichia coli enteroagregativa com tecido intestinal humano, a fim de documentar potenciais alterações em diferentes regiões do trato digestivo. MÉTODOS: Amostras de Escherichia coli enteroagregativa isoladas das fezes de crianças com diarreia persistente e a amostra protótipo 042, isolada de uma criança com diarreia em Lima, no Peru (controle positivo), foram analisadas por microscopia óptica de luz após semeadura em cultura de orgão in vitro de fragmentos de mucosa ileal e colônica. Foram analisadas as interações entre as diferentes cepas de Escherichia coli enteroagregativa e as mucosas ileal e colônica. RESULTADOS: A análise por microscopia óptica de luz indicou associação destes micro-organismos com o epitélio, provocando alterações. As cepas estudadas aderiram a ambas as regiões avaliadas (intestino delgado distal e grosso) e causaram alterações, especialmente naquelas áreas onde interagiram diretamente com o epitélio. No íleo, algumas regiões mostraram internalização secundária. CONCLUSÕES: Esses agentes podem causar diarreia persistente por meio de alterações no intestino delgado, no qual ocorrem as funções digestivo-absortivas. As lesões inflamatórias descritas na mucosa colônica poderiam explicar a colite mostrada em algumas crianças infectadas por Escherichia coli enteroagregativa.

OBJECTIVE: To examine the interactions of Enteroaggregative Escherichia coli strains with small and large intestinal mucosa, in order to detect potential alterations in both regions of the digestive tract. METHODS: Enteroaggregative Escherichia coli strains, isolated from stools of infants with persistent diarrhea and the prototype strain 042 (O44:H18), isolated from a child with diarrhea in Lima, Peru (positive control), were analised by light microscopy after in vitro organ culture assay of ileal and colonic mucosa. The interactions between the different enteroaggregative Escherichia coli strains and the ileal and colonic mucosa were analysed. RESULTS: Light microscopy analysis suggested an association of enteroaggregative Escherichia coli strains with the epithelium, inducing alterations. These bacteria adhered to both small and large bowel mucosa. The enteroaggregative Escherichia coli strains induced alterations in those areas where they were directly interacting with the epithelium. In the ileum, some areas showed a secondary internalization. CONCLUSIONS: The enteroaggregative Escherichia coli strains could cause persistent diarrhea inducing alterations in the small intestinal structures, where the digestive-absorptive functions take place. Inflammatory lesions observed in colons could justify the colitis described in some children infected by enteroaggregative Escherichia coli.

OBJETIVO: Evaluar interacciones de muestras de Escherichia coli enteroagregativa (EAEC) con tejido intestinal humano, a fin de documentar potenciales alteraciones en distintas regiones del tracto digestivo (intestino delgado distal e intestino grueso) y definir, con eso, su rol en la persistencia del proceso diarreico. MÉTODOS: Muestras de EAEC aislada de las heces de niños con diarrea persistente y la muestra prototipo 042, aislada de un niño con diarrea en Lima, Perú (control positivo) fueron analizadas por microscopía óptica de luz (ML) después de siembra en cultura de órgano in vitro de fragmentos de mucosa ileal y del colon. Fueron analizadas las interacciones entra las distintas cepas de EAEC y las mucosas ileal y del colon. RESULTADOS: El análisis por ML indicó asociación de estos microorganismos con el epitelio, provocando alteraciones. Las cepas estudiadas adhirieron a ambas regiones evaluadas: intestino delgado distal y grueso y causaron alteraciones, especialmente en aquellas áreas donde interactuaron directamente con el epitelio. En el íleo, algunas regiones mostraron internalización secundaria. CONCLUSIÓN: Estos agentes pueden causar diarrea persistente mediante alteraciones en el intestino delgado, donde ocurren las funciones digestivo-absortibas. Las lesiones inflamatorias descritas en la mucosa del colon podrían explicar la colitis descrita en algunos niños infectados por EAEC.

[Prevalence and multi-drug resistance of enteropathogenic Escherichia coli [EPEC] isolated from children under 5 years of age with diarrhea in Kashan Shahid Beheshti hospital during 2009-10]

Enteropathogenic Escherichia coli [EPEC] is the most important diarrheagenic agent among children in developing countries. However, recent studies have shown its prevalence in developed countries. The purpose of this study was to evaluate the prevalence and multi-drug resistant [MDR] of EPEC isolated from children under 5 years of age with diarrhea hospitalized in Kashan Shahid Beheshti hospital during 2009-10. In this descriptive study 313 fecal specimens were collected using rectal swab method from all children under 5 years of age with diarrhea hospitalized in Kashan Shahid Beheshti Hospital during 2009-10. Specimens were examined by PCR test to determine the eae Gene for detection of EPEC pathotype. The isolated multi-drug resistance pattern of EPEC was evaluated by disk diffusion agar. The antimicrobial disks used were ampicillin, nalidixic acid, ceftriaxone, ciprofloxacin, cefalexin, ceftazidime, streptomycin and imipenem. Of all 178 E. coli cases 51 [28.6%] EPEC pathotypes were isolated. The prevalence of EPEC was higher in children under 1 year of age. MDR rate in EPEC was 70.6%. The exact application of antibiogram test is necessary before antibiotic prescription for complete treatment and prevention of diarrhea caused by multi-drug resistance agents

Escherichia coli diarreogénica asociada a casos de diarrea aguda en niños de Cumaná, Venezuela / Diarrheagenic Escherichia coli associated with acute diarrhea in children of Cumana, Venezuela

Para establecer la prevalencia de cepas de E. coli diarreogénicas (ECD) asociadas a casos de diarrea aguda infantil en Cumaná, Venezuela; se tomaron muestras de heces de 200 niños con enfermedad diarreica aguda, menores de 5 años, y de 30 niños sanos incluidos como control. El aislamiento e identificación bacteriana se realizó por coprocultivos y pruebas bioquímicas convencionales. Para determinar la presencia de los genes de patogenicidad de cada tipo de ECD se usó la técnica de reacción en cadena de la polimerasa (PCR), determinando los genes eae y bfp (ECEP), st y lt (ECET), ipaH y virF (ECEI), Stx1/Stx2 (ECST), aafII (ECEA) y daaE (ECAD). Se realizaron 169 aislamientos de E. coli, de las cuales se determinó por PCR que el 10,65% fueron positivas para ECEP (1,18% “típicas”; 9,47% “atípicas”); ECET (5,91%); ECEA (1,78%); ECEI (0,59%). No se observaron diferencias estadísticas significativas en cuanto a la frecuencia de cada “patotipo” en relación a la edad, pero si en relación con el sexo (p< 0,05). Las características clínicas más relevantes fueron: fiebre, vómito y dolor abdominal y el mayor porcentaje de los niños afectados estuvo en las clases obrera y marginal. Estos resultados muestran que las cepas de ECD, son agentes etiológicos importantes en la enfermedad diarreica aguda infecciosa en la población infantil de Cumaná.

To establish the prevalence of strains of diarrheagenic Escherichia coli (DEC) associated to acute diarrhea in childrem of Cumaná, Venezuela, stool samples were taken from 200 children aged < 5 years with acute diarrheal disease, and from 30 healthy children used as control. Isolation and bacterial identification was performed by conventional biochemical tests and stool cultures. The presence of pathogenic genes of each type of DEC was investigated by the technique of polymerase chain reaction (PCR), determining the genes eae and bfp (EPEC), st and lt (ETEC), ipaH and virF (EIEC) Stx1/Stx2 (STEC), aafII (EAEC) and daaE (ADEC). From 169 E. coli, isolates we determined by PCR 10.65% positive for EPEC (1.18% “typical”, 9.47% “atypical”); ETEC (5.91%); EAEC (1.78 %), EIEC (0.59%). There were no statistically significant differences regarding the frequency of each “pathotype” in relation to age, but it did occur when related to the sex (p<0.05). The most relevant clinical features were: fever, vomiting and abdominal pain and the greatest percentage of children affected were of the working and marginal classes. These results shown that the strains of DEC are important etiological agents in acute infectious diarrhea in children of Cumaná.

Caracterización de aislamientos de Vibrio cholerae no-O1, no-O139 asociados a cuadros de diarrea / Characterization of Vibrio cholerae non-O1 and non-O139 isolates associated with diarrhea

La infección por Vibrio cholerae, el agente causal del cólera, se trasmite al hombre por ingestión de agua y alimentos contaminados. Aunque son los serogrupos O1 y O139 los que habitualmente se asocian al cólera epidémico, los aislamientos de otros serogrupos también son causales de gastroenteritis e infecciones extra-intestinales. Durante el período 2003-2005, se investigó la presencia de V. cholerae en la materia fecal de niños con diarrea atendidos en el Hospital del Niño Jesús, Tucumán. Se recuperaron 34 aislamientos de V. cholerae no-O1, no-O139. Se determinaron sus perfiles de virulencia por PCR, la sensibilidad a los antimicrobianos y la diversidad genética por electroforesis en campo pulsado. Se obtuvieron ocho perfiles de virulencia, aunque ningún aislamiento fue positivo para la toxina colérica ni para la toxina termoestable. Cuatro aislamientos fueron positivos para el sistema de secreción de tipo tres. El 17,6% de los aislamientos fueron resistentes o de sensibilidad intermedia a ampicilina y el 5,9% fueron resistentes a trimetoprima-sulfametoxazol. Los aislamientos resultaron muy diversos: se hallaron 27 patrones distintos en 29 aislamientos tipificables por electroforesis en campo pulsado. A pesar de su baja incidencia, V. cholerae continúa siendo un agente causal de diarrea en niños, los que se ven afectados por una amplia variedad de cepas circulantes.

Vibrio cholerae, etiologic agent of cholera, is transmitted to humans by ingestion of contaminated food or water. Even though serogroups O1 and O139 are the ones usually associated to epidemic cholera, isolates from other serogroups also cause gastroenteritis and extraintestinal infections. During the period 2003-2005, presence of V. cholerae in stools was investigated in children with diarrhea that seaked assistance at the Niño Jesús Hospital in Tucumán. Thirty four isolates of V. cholerae non-O1, non-O139 were recovered. We characterized the isolates studying its virulence factors by PCR, antimicrobial susceptibility patterns and genetic diversity by pulsed-field gel electrophoresis. Eight virulence patterns were obtained although no isolate was positive for the cholera toxin or the thermostable toxin. Four isolates were positive for the type three secretion system. The 17.6% of the isolates were resistant or intermediate to ampicillin and 5.9% were resistant to trimethoprim-sulfamethoxazole. By SfiI-PFGE, all isolates were genetically very diverse, as 27 different patterns were identified in 29 typeable isolates by pulsed-field gel electrophoresis. Although it has a low incidence, V. cholerae continues to be a causative agent of diarrhea in children, who are affected by a variety of circulating strains of V. cholerae non-O1, non-O139.

Patogénesis molecular, epidemiología y diagnóstico de Escherichia coli enteropatógena / Molecular pathogenesis, epidemiology and diagnosis of enteropathogenic Escherichia coli

Escherichia coli enteropatógena (EPEC) es una de las principales causas de diarrea en niños menores de dos años en países en vías de desarrollo. La principal característica histopatológica de la infección es una lesión que induce la EPEC en el intestino conocida como la lesión A/E (adherencia y eliminación). Las bacterias se adhieren a los enterocitos y permiten la acumulación de la actina del citoesqueleto en la región apical de la célula, hasta formar una estructura de tipo "pedestal" y causar la eliminación de las microvellosidades intestinales. A pesar de que se conoce de modo detallado el proceso de formación de los pedestales de actina, aún no se ha esclarecido el mecanismo global de la diarrea que induce EPEC. La diarrea se ha vinculado con: a) la destrucción de las microvellosidades del enterocito, b) la salida masiva de iones hacia la luz intestinal y c) la secreción de alguna enterotoxina. En estudios realizados en países en vías de desarrollo se ha demostrado que EPEC es uno de los principales agentes participantes en la diarrea infantil, con elevadas tasas de morbilidad y mortalidad. El diagnóstico microbiológico de la infección se realiza con metodologías adicionales a las utilizadas con regularidad en el laboratorio de microbiología clínica, entre ellas las siguientes: a) serotipificación, b) ensayo de adherencia, c) prueba de FAS (tinción fluorescente para actina) y d) detección específica de genes que codifican a proteínas incluidas en la patogénesis, como el bfpA y eae. Un objetivo de esta revisión es actualizar los avances observados en la patogénesis molecular de la infección por EPEC, las metodologías para el diagnóstico microbiológico y la epidemiología en México y otros países en vías de desarrollo.

Enteropathogenic Escherichia coli (EPEC) is a leading cause of diarrhea in infants less than two years of age in developing countries. To induce diarrhea EPEC uses several virulence factors acting on a still unknown and mysterious mechanism. The hallmark of EPEC infection is a histological intestinal alteration known as the attaching and effacing (A/E) lesion. The bacterium attaches intimately to the enterocyte and induces assembly of cytoskeleton intracellular actin on the cellular surface. Rearrangements of the actin cytoskeleton form a pedestal-like structure where bacterium tightly cups the cells, leading to degeneration of brush border microvilli. Although the mechanism of EPEC-induced pedestal formation has been dissected in detail, the overall mechanism of diarrhea is still obscure. It is believed that EPEC-mediated secretory diarrhea is related to a) intestinal microvilli effacement, b) massive loss of intracellular ions into the intestinal milieu and c) secretion of an EPEC enterotoxin. Epidemiological studies conducted in developing countries have shown that EPEC is one of the main bacteria frequently isolated from children with diarrhea, causing high morbidity and mortality rates. The microbiological diagnosis of EPEC-induced disease is performed with analytic methodologies different from those used by the standard microbiology laboratory, the most relevant being: a) serotypification, b) the adherence assay, c) FAS test, and d) the specific detection of virulence-involved genes (bfpA and eae genes) using molecular biology techniques. The purpose of this review is to update the most recent findings regarding the molecular pathogenesis of EPEC, its epidemiology in Mexico as well as other developing countries, and also the developed methodology for the diagnosis of EPEC infection.

Agentes causantes de diarrea en niños menores de 5 años en Tunja, Colombia / Diarrhoea-causing agents in children aged less than five in Tunja, Colombia

Objetivos: Determinar la prevalencia y tipo de agentes infecciosos causantes de EDA en una muestra de niños menores de 5 años que consultaron a IPS de Tunja durante el año 2004. Materiales y Métodos Estudio de corte transversal, la información se recogió mediante aplicación de una encuesta a 129 niños menores de 5 años afectados de EDA. Adicionalmente se recogió una muestra de heces, en las consultas externas del Hospital San Rafael y Clínica Saludcoop de Tunja. Resultados Se encontró Rotavirus en 48,1 por ciento, Shigella 0,8 por ciento, E. coli 13,9 por ciento; Campylobacter 2,3 por ciento; Giardia lamblia 12,4 por ciento; E. histolytica 7 por ciento; en 15,5 por ciento de casos no se identificó agente causal. La asociación es creciente con la edad para Rotavirus (p<0,01), E.Coli (p<0,05) y Campylobacter (p<0,001). Conclusión Rotavirus es el mayor agente causal de EDA en menores de 1 año, y en general, en menores de 5 años. Las prevalencias encontradas coinciden con lo reportado en estudios realizados en Facatativá, Bogotá, Santander, Manizales y Chocó; también con estudios adelantados en Venezuela, Perú y México.

Objectives: Determining the prevalence and type of infectious ADD-causing agents in a sample of children aged less than five who consulted the IPS in Tunja during 2004. Material and Methods A cross-sectional study was designed. Data was obtained by surveying 129 children younger than 5 suffering from ADD. Samples of faeces were obtained following outpatient consultation at San Rafael Hospital and SaludCoopÆs clinic in Tunja. Results Rotavirus was found in 48,1 percent of cases, Shigella in 0,8 percent, E. coli in 13,9 percent, Campylobacter in 2,3 percent, Giardia lamblia in 12,4 percent and E. hitolytica in 7 percent. The causative agent could not be identified in 15,5 percent of cases. The statistical association grew with age for Rotavirus (p<0.01), E. coli (p<0.05) and campylobacter (p<0.001). Conclusion Rotavirus is the major causative agent of ADD in children younger than one year and, generally, in children aged less than five. The prevalence found was similar to data reported in studies carried out in Facatatativá, Bogotá, Santander, Manizales and the Chocó in Colombia and studies carried out in Venezuela, Peru and Mexico.

Complementary foods associated diarrhea.

The World Health Organization regards illness due to contaminated food as one of the most widespread health problems in the contemporary world. Food safety especially in the weaning groups is one of the major concerns that have posed a threat to health of the children. Millions of children in the world die each year from diarrheal diseases; hundreds of millions suffer from frequent episodes of diarrhea and consequent impairment of nutritional status. Contaminated foods play a major role in the occurrence of diarrheal diseases. Apart from food contamination, transmission of infection occurs by direct contact, highly favored by the habits and customs of the people. Improper storage and handling of cooked food is equally responsible for food-borne illnesses, as during storage especially at ambient temperature (28-38 degrees C) there is the risks of multiplication of pathogenic organisms increase. Food safety education is a critical prerequisite and is an essential element in control and prevention of diarrheal diseases. However, no preventive measures can ever be successful without the acute involvement of the caretakers, other family members and the community. To sensitize the community in a catalytic manner, health workers, community leaders and community volunteers can act as effective change agent, to bring about a behavior that can lead to improvement in their real life practices, thereby reducing the prevalence of diarrheal episodes in young children. Food Safety Education Programs that involve volunteers are cost effective as they can be reached to a maximum number of people through limited health personnels, and by this, the community can be made responsible for its own health problems.

Aislamiento de Escherichia coli productor de toxina Shiga durante un brote de gastroenteritis en un Jardín Maternal de la Ciudad de Mar del Plata / Isolation of Shiga toxin-producing Escherichia coli strains during a gastrointestinal outbreak at a day care center in Mar del Plata City

Entre el 15 de octubre y el 8 de noviembre de 2003 ocurrió un brote de gastroenteritis en un Jardín Maternal de un Hospital de la ciudad de Mar del Plata. Catorce de un total de 80 niños (17,5%), edad promedio 23,6 ± 13,9 meses, presentaron diarrea, y un caso evolucionó a síndrome urémico hemolítico. La madre de uno de los afectados presentó diarrea simultáneamente. No se pudo establecer el origen del brote, pero probablemente la transmisión haya sido fundamentalmente persona a persona. Las prácticas habituales en el lactario del jardín maternal, y las condiciones inadecuadas de infraestructura y hábitos de higiene de la cocina del Hospital fueron señalados como factores de riesgo. En un caso se detectó Escherichia coli productor de toxina Shiga (STEC) O103:H2, y STEC O26:H11 en otro. En el niño infectado por STEC O26:H11, la excreción se extendió por un período de 37 días. La no detección de STEC en aquellos casos en los cuales el intervalo entre el inicio de los síntomas y la toma de muestra fue mayor a 6 días, enfatiza la necesidad de la recolección temprana de especímenes. Las principales conclusiones de este estudio fueron la necesidad de establecer normas óptimas de higiene, informar rápidamente la ocurrencia de casos de gastroenteritis y confirmar la negativización de la excreción del patógeno.

From October 15 to November 8, 2003, a gastrointestinal outbreak occurred at a day care center in a Hospital in Mar del Plata City. Fourteen out of 80 (17.5%) children, mean age 23.6 ± 13.9 months, and the mother of one of them had diarrhea. One case developed hemolytic uremic syndrome. No conclusive evidence of the origin of the outbreak was found, but the epidemic curve suggested person-to-person spread. The usual practices at the place where infant milk formula was prepared at the day care center, together with the inadequate infrastructure conditions and hygiene practices at the kitchen of the hospital, were considered risk factors. One case had Shiga toxin-producing Escherichia coli (STEC) O103:H2 infection and other STEC O26:H11.The duration of shedding for the child with O26:H11 infection was 37 days. In the other symptomatic children, the pathogen was not recovered from fecal samples collected 6 or more days after the onset of the illness. This emphasizes that the collection of early samples is necessary to recover STEC strains. In order to prevent and control enteric diseases in day care facilities the following measures are necessary: optimal hygiene standards, early case reporting, and exclusion of those who remain culture-positive.

IgA secretora total e específica no colostro e leite de mães da cidade do Natal-Rio Grande do Norte, Brasil / Total and specific IgA in colostrum and milk of mothers of Natal-Rio Grande do Norte, Brasil

PURPOSE: To determine the concentration of total secretory IgA and evaluate the repertoire of IgA antibodies to enteropathogenic Escherichia coli and Shigella flexneri antigens in colostrums and milk from mothers in Natal, RN. METHODS: The sample was constituted by 22 healthy clinically women whose babies were born at public hospital in Natal, RN. To determine total secretory IgA a radial immunedifusion tecnique (Mancini et al, 1965), was employed and to detect specific antibodies, immuneenzimatic assays, ELISA was used. RESULTS: The median values of total secretory IgA concentration presented individual variations with high levels in colostrums samples, decreasing during lactation, it was observed a p < 0.001 among the samples from the first day of lactation, to the thirtieth for total IgA concentration. All the donators present in colostrum and milk specific antibodies to Escherichia coli enteropathogenic (EPEC) and Shigella flexneri with titles higer in colostrum. There was parallel and directional pattern between total IgA and IgA anti-EPEC and Shegella flexneri, during period. CONCLUSION: The concentrations of total SIgA and specific antibodies to enteropathogenic Escherichia coli and Shigella flexneri in colostrums and milk in our study do not differ from others accomplished among populations with the same social and econimic features, stressing the importance of human milk as a protector agent against pathogens.

Effect of bifidobacterium Bb12 with or without Streptococcus thermophilus supplemented formula on nutritional status.

Acute diarrhea is a common cause of infant morbidity and mortality. Probiotic supplemented infant formula is one of the effective methods for prevention of rotavirus diarrhea. Other benefits of the probiotics supplemented formula were evaluated by monitoring the growth of the children. A double-blind, placebo-controlled trial was done in 148 children aged 6-36 months. They were divided into 3 groups: the Bb12 group, 51 children received infant formula with Bifidobacteria Bb12 supplement; the Bb12+ST group, 54 children received infant formula with Bb12 and Streptococcus thermophilus supplement; and the control group, 43 children received infant formula without supplement. The mean weight Z-score according to WHO reference standard of the Bbl2 group was -1.8 +/- 0.12, the Bb12+ST group was -1.4 +/- 0.11 and the control group was -1.8 +/- 0.13 at entry. The mean weight Z-score of children after 6 month showed that the children in the Bbl2+ST group had the highest increase in weight which was increased from -1.4 +/- 0.11 to -0.9 +/- 0.12 compared to the Z-score of the Bb12 group which had increased from -1.8 +/- 0.12 to -1.2 +/- 0.13 and in the control group from -1.8 +/- 0.13 to -1.7 +/- 0.25. In terms of the mean height Z-score, the Bb12 group was -2.7 +/- 0.14 to -1.7 +/- 0.16 which was higher than the Bb12+ST group (- 2.2 +/- 0.13 to -1.7 +/- 0.13) but was not different from the control group. However, the mean weight/height Z-score of the Bbl2+ST group had approached the reference standard (Bb12 group -0.1 +/- 0.11 to -0.1 +/- 0.13, Bb12+ST group -0.1 +/- 0.10 to 0.3 +/- 0.17, control group -0.4 +/- 0.12 to -0.1 +/- 0.16). Data showed that children who received the probiotics supplement formula had better growth during the 6 month period.

Vibrio cholerae diarrhoea in a three-day-old breastfed neonate.

A confirmed case of cholera in a 3-day-old neonate is being reported. Possible source of infection could be by holy water (Chamamrit) given to the baby, which is common ritual in India. Mother's milk has never been reported to transmit cholera, even though mother herself may be suffering from cholera. Contaminated water can transmit the disease as there is no maternally transmitted immunity.

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

Identificaçäo de rotavirus associado ao sorotipo G2 Yucatan, México / Identificacion of rotavirus associated to setory G2 in Yucatan, Mexico

Neste estudo reporta-se a identificaçäo de rotavirus sorotipo G2 proveniente de amostras fecais de crianças com gastroenterite, da Cidade de Mérida, Yucatan, México. O diagnóstico virológico foi feito através da eletroforese em gel de poliacrilamidia e ensaio imunoenrimático. Das 149 amostras estudadas, 25 (16,7 por cento) foram positivas para rotavirus do grupo A; dessas 23 (92 por cento) foram sorotipo G2, subgrupo I e padräo eletroforético curto e 2 (8 por cento) subgrupo II e padräo eletroforético longo, porém, näo foi possível determinar o sorotipo G. Desde 1985, até hoje, foi a única vez que o sorotipo G2 foi identificado, em mais de 90 por cento das amostras analisadas. Acredita-se que, provavelmente, nos últimos anos tem acumulado na populaçäo, um grupo de pessoas suscetíveis ao sorotipo de RV; e num futuro poderia ter um surto importante de gastroenterite, associado ao sorotipo G2 de rotavirus

Asymptomatic infections by diarrheagenic Escherichia coli in children from Misiones, Argentina, during the first twenty months of their lives

Diarrheagenics Escherichia coli are the major agents involved in diarrheal disease in developing countries. The aim of this study was to evaluate the time of appearance of the first asymptomatic infection by the different categories of diarrheagenic E. coli in 44 children since their birth and during the first 20 months of their lives. In all of the children studied, we detected at least one category of diarrheagenic E. coli through the 20 months of the study. 510 diarrheagenic E. coli (33.5 percent) were obtained from the 1,524 samples collected from the 44 children during the time of the study (31.4 percent EAggEC, 28.8 percent EPEC, 27.1 percent DAEC, and 12.7 percent ETEC). Neither EHEC nor EIEC were identified. The median age for diarrheagenic E. coli colonization was 7.5 months. The mean weaning period was 12.8 months and the mean age for introduction of mixed feeding (breast fed supplemented) was 3.8 months. A significantly lower incidence of diarrheal disease and asymptomatic infections was recorded among the exclusively breast-fed rather than in the supplemented and non breast-fed infants. For ETEC, EPEC and EAggEC the introduction of weaning foods and complete termination of breast-feeding were associated with an increase of asymptomatic infections

The gut at war: the consequences of enteropathogenic Escherichia coli infection as a factor of diarrhea and malnutrition

Diarrheal disease is still the most prevalent and important public health problem in developing countries, despite advances in knowledge, understanding, and management that have occurred over recent years. Diarrhea is the leading cause of death in children under 5 years of age. The impact of diarrheal diseases is more severe in the earliest periods of life, when taking into account both the numbers of episodes per year and hospital admission rates. This narrative review focuses on one of the major driving forces that attack the host, namely the enteropathogenic Escherichia coli (EPEC) and the consequences that generate malnutrition in an early phase of life. EPEC serotypes form dense microcolonies on the surface of tissue-culture cells in a pattern known as localized adherence (LA). When EPEC strains adhere to epithelial cells in vitro or in vivo they cause characteristic changes known as Attaching and Effacement (A/E) lesions. Surface abnormalities of the small intestinal mucosa shown by scanning electron microscopy in infants with persistent diarrhea, although non-specific, are intense enough to justify the severity of the clinical aspects displayed in a very young phase in life. Decrease in number and height of microvilli, blunting of borders of enterocytes, loss of the glycocalyx, shortening of villi and presence of a mucus pseudomembrane coating the mucosal surface were the abnormalities observed in the majority of patients. These ultrastructural derangements may be due to an association of the enteric enteropathogenic agent that triggers the diarrheic process and the onset of food intolerance responsible for perpetuation of diarrhea. An aggressive therapeutic approach based on appropriate nutritional support, especially the utilization of human milk and/or lactose-free protein hydrolyzate-based formulas and the adequate correction of the fecal losses, is required to allow complete recovery from the damage caused by this devastating enteropathogenic agent

Diversidades fenotípica e genotípica em amostras de Escherichia coli enteroagregativa com variaçörs no padräo de aderência e/ou na reatividade com a sonda EAEC / Phenotypic and genotypic diversities in enteroaggregative Escherichia coli strains with variations in the adherence pattern and/ or reactivity with the EAEC probe

Amostras de Escberichia coli enteroagregativa (EAEC) tem sido epidemiologicamente associada com diarréia persistente em diversos países em desenvolvimento e são identificadas por sua habilidade de produzir um padrão de aderência agregativo (AA) na superfície de células HEp-2 e HeLa e na região intercelular de suporte. A maioria dos estudos até o momento enfocaram na virulência da categoria EAEC tem analisado amostras que produziam padrão AA típico e reagiam com a sonda EAEC (pCVD 432). Desta forma, poucas informações relativo à presença de potenciais fatores de virulência em amostras de E. coli apresentando variações no padrão de aderência AA e/ou defectivo para a seqüência EAEC tem sido reportado. Neste estudo, nós analisamos 26 amostras de E. coli classificadas em 6 grupos distintos, de acordo com variações no padrão de aderência AA e/ou na reatividade com a sonda EAEC. Estes grupos foram classificados como: AA/+ (AA típico/sonda positiva), AA/- (AA típico/sonda negativa), D/+ (destacantes/sonda positiva), AAcs/+ (AA preferencialmente na lamínula/sonda positiva), AAcs/- (AA preferencialmente na lamínula/sonda negativa) e NA/+ (não aderentes/sonda positiva). Diversas propriedades fenotípicas e genotípicas foram pesquisadas com o propósito de caraterizar e comparar as amostras dentro e entre estes grupos. A habilidade de produzir uma agregado bacteriano (película) na superfície de meio de cultura líquido foi investigado. Esta propriedade foi observada na maioria das amostras EAEC e variantes, entretanto parece que esta característica fenotípica está principalmente relacionada com amostras que abergam a seqüência EAEC (88,8 por cento versus 55,5 por cento, respectivamente). A reatividade com a sonda pVAP foi avaliada como um método alternativo para identificação de amostras de E. coli pertencentes a categoria EAEC, mas a sensibilidade desta sonda genética foi similar a da sonda EAEC (l7 por cento). A habilidade de aglutinar diferentes tipos de eritrócitos (humano do grupo sangüíneo A, bovino, carneiro, galinha e cobaia) na presença ou ausência de D-manose foi também investigada. Metade das amostras EAEC deste estudo apresentou atividade hemaglutinante manose-resistente ) pelo menos a um dos 5 tipos de eritrócitos. É interessante destacar que a atividade foi mais freqüentemente encontrada entre as amostras que reagiram com a sonda EAEC (64,7 por cento vs. 22,2 por cento nas amostras sonda EAEC negativas), um achado...(au)