O objetivo deste estudo foi avaliar a suplementação de um probiótico composto por cepas de Bacillus subtilis e Bacillus licheniformis, fornecidos via sucedâneo lácteo, no que se refere ao escore e pH fecal, contagem de microrganismos intestinais, parâmetros sanguíneos e desempenho geral dos animais. Foram utilizados 24 animais da raça Holandês que receberam 4L/dia de sucedâneo comercial (15PB:15EE), além de livre acesso a água e concentrado inicial. O desaleitamento ocorreu na 8ª semana de vida. Os animais foram distribuídos em delineamento de blocos casualizados, em dois tratamentos: 1) Controle - sem a suplementação de probiótico; 2) Suplementação de 2g/d (1,6 x 109 UFC) de Bacillus subtilis e Bacillus licheniformis via sucedâneo lácteo. Semanalmente foram realizadas pesagens e aferições de medidas corporais (altura de cernelha, perímetro torácico e largura de garupa); e colheitas de sangue para determinação de glicose, proteína total, ureia e albumina, além de determinação de hematócrito. Foram colhidas amostras semanalmente para contagem de bactérias ácido láticas e enterobactérias e determinação de pH fecal. O monitoramento do consumo de concentrado e do escore fecal foi realizado diariamente. O peso corporal, o ganho de peso médio diário e as medidas corporais não foram alteradas (P>0,05) pela suplementação do probiótico contendo Bacillus subtilis e Bacillus licheniformis; muito embora tenham apresentado efeito significativo de idade dos animais (P<0,001). O escore fecal, pH fecal e consumo de concentrado diário também não foram afetados pela suplementação com probiótico. No entanto, o consumo de concentrado e o pH fecal sofreram influência da idade em resposta ao crescimento natural dos bezerros. A contagem de bactérias ácido láticas foi maior que número de enterobactérias durante todo o período (P<0,05). Apenas as enterobactérias sofreram efeito da idade (P<0,05), enquanto as bactérias ácido láticas permaneceram variando, porém dentro de um padrão constante. Os parâmetros sanguíneos também não foram afetados pela suplementação com probiótico (P>0,05) mas todos, com a exceção da albumina, tiveram influência da idade (P<0,001). A suplementação com o probiótico contendo Bacillus subtilis e Bacillus licheniformis via sucedâneo não apresentou benefícios no desempenho ou no metabolismo de bezerros leiteiros, bem como não reduziu a ocorrência de casos de diarreia. / The objective of this study was to evaluate the supplementation of a probiotic containing strains of Bacillus subtilis and Bacillus licheniformis, supplied via milk replacer, with regard to fecal score and pH, intestinal microorganisms count, blood parameters and overall performance of the animals. Twenty-four Holstein calves were utilized and received 4L/d of liquid diet consisting of commercial milk replacer (20CP:15EE), and had free access to water and starter concentrate. Weaning occurred at the 8th week of age. Animals were distributed in a randomized block design, in the following treatments: 1) Control - without supplementation with probiotic, 2) Supplementation: 2g/d of Bacillus subtilis and Bacillus licheniformis (1.6 x 109 CFU), via milk replacer. Every week calves were weighted and body measurements were taken (hip width, withers height and heart girth). Blood samples were drawn weekly for determination of hematocrit, glucose, total protein, urea and albumin. Fecal samples were weekly collected for lactic acid bacteria and enterobacteria couting and fecal pH determination. Concentrate starter intake and fecal scores were monitored daily. Body weight, average daily gain, and corporal measurements were not affected (P>0,05) by the supplementation of probiotic; however, presented a significant age effect (P<0,001). The fecal score, fecal pH and starter intake were not affected by probiotic supplementation (P>0.05). However, starter intake and fecal pH were affected by age due to calves\' natural growth. The acid lactic bacteria count was higher than the count of enterobacteria during the whole evaluation period. Only enterobacteria were affected by the age of animals, while acid lactic bacteria remained constant despite little variations. Blood parameters were also not affect by supplementation of probiotic (P>0.05), but all of them, except albumin concentrations, were influenced by age (P<0,001). The supplementation with probiotic containing Bacillus subtilis and Bacillus licheniformis via milk replacer presented no benefits in dairy calves performance or metabolism and did not reduced the occurrence of diarrhea.

Com o objetivo de validar um protocolo de indução de diarréia osmótica e avaliar comparativamente a eficácia de três diferentes tratamentos, foram utilizados 18 bezerros holandeses hígidos, com idade entre oito e 30 dias, e peso variando entre 37 e 50 Kg. A diarréia e a desidratação foram induzidas por via oral, através da administração de leite integral (16,5 ml/Kg), de quatro gramas de sacarose por quilo e de dois tipos de diuréticos (espirolactona e hidroclorotiazida, em dose de 2mg/Kg), a cada oito horas, por um período de 48 horas. Os bezerros foram distribuídos aleatoriamente por três grupos experimentais, cada um com seis animais, que receberam as seguintes soluções: solução salina hipertônica à 7,5% (SSH-4ml/kg IV), solução eletrolítica oral (SEI-60ml/kg) e a associação dessas duas soluções (SSH+SEI), sendo a SEI administrada por mais duas vezes com um intervalo de oito horas. O exame físico e as colheitas de sangue para determinações do hemograma, de dosagens hemogasométricas e de componentes bioquímicos séricos e plasmáticos foram realizadas nos seguintes momentos: 0h (antes da indução), 24 e 48 horas pós-indução(PI) de diarréia, e com 1, 3, 6, 12, 24, 48 e 72 horas pós-tratamento (PT).As amostras de fezes e urina foram colhidas às 0h, 24 e 48 horas PI, e 24, 48 e 72 horas PT. O protocolo de indução da diarréia obteve 100% de resposta produzindo diarréia aquosa e desidratação severa (equivalente a 13% do peso corpóreo) acompanhada de azotemia pré-renal, aumentos no volume globular, no teor de hemoglobina e na proteína total; hipercalemia; hiperlactemia; hiperfosfatemia; acidose metabólica; elevado déficit de volume plasmático; aumentos da densidade urinária, da concentração de uréia e creatinina urinárias e do lactato urinário e fecal; diminuições da pressão venosa central, do pH urinário e fecal. Os animais tratados com SSH+SEI diminuíram de forma rápida e substancial os valores do volume globular e do déficit de volume plasmático; aumentaram o pH sangüíneo e a pressão venosa central entre 1hPT e 3hPT, além de manterem as concentrações de glicose próximas aos valores basais durante todo o período de tratamento. A SEI também promoveu o restabelecimento das variáveis anteriormente citadas, porém de forma mais lenta quando comparada com o uso da SSH+SEI. Os animais tratados apenas com SSH exibiram, no monitoramento através de exames físico e laboratoriais, sinais de desidratação, de depressão clínica e de acidose metabólica ainda às 24hPT, indicando que o uso isolado dessa solução não é eficaz no tratamento da diarréia em bezerros neonatos. / With the purpose of validating a protocol for osmotic diarrhea induction and to comparatively evaluate the efficacy of three different treatments, 18 healthy Holstein calves, with eight to 30 days old, and 37 to 50 Kg of body weight were used. The diarrhea and dehydration were orally induced, through the administration of whole milk (16.5 ml/Kg bwt), sucrose 4g/Kg bwt and two types of diuretics (spironolactone and hydrochlorothiazide, in a dosage of 2mg/Kg bwt), every eight hours, for a total period of 48 hours. The calves were randomly distributed into three experimental groups, each one with six animals, which received the following solutions: 7.5% hypertonic saline solution (HSS - 4ml/Kg bwt, IV), oral electrolytic solution (OES - 60ml/Kg bwt) and the association of both solutions (HSS+OES), being the OES administered two more times with an interval of eight hours. The physical examination and blood sampling for hemogram determinations, hemogasometric dosages and serum and plasmatic biochemical components were done in the following moments: 0h (before the induction), 24 and 48h post-induction (PI) of diarrhea, and within 1, 3, 6, 12, 24, 48 and 72 hours post-treatment (PT). The protocol for osmotic diarrhea induction had a 100% response with aqueous diarrhea and severe dehydration (corresponding to 13% of body weight), followed by pre-renal azotemia, increases in the globular volume, and hemoglobin and total protein levels; hyperkalemia; hyperlactemia; hyperphosphatemia; metabolic acidosis; high plasmatic volume deficit; increases of urinary density, urinary urea and creatinine concentrations and urinary and fecal lactate; diminished central venous pressure and urinary and fecal pH. The animals treated with HSS+OES rapidly and substantially diminished the values of globular volume and plasmatic volume deficit; had the blood pH and central venous pressure increased between 1hPT and 3hPT, besides they maintained glucose concentrations near basal values along the period of treatment. The OES also promoted the reestablishment of the cited variables, although in a slower manner when compared with the use of HSS+OES. The animals treated only with HSS showed, through the physical and laboratory exams, signs of dehydration, clinical depression and metabolic acidosis still at 24hPT, indicating that the isolated use of this solution is not efficient in the treatment of neonatal diarrhea in calves.

As diarréias neonatais constituem-se em um dos mais importantes fatores econômico e sanitário nas granjas suínas, quer pela mortalidade, quer pelas perdas agregadas ao atraso no desenvolvimento dos leitões, à profilaxia e ao manejo. Os rotavírus ocupam lugar de destaque pela rápida disseminação dentro do plantel, bem como pelo potencial zoonótico, dada a probabilidade de rearranjo ou recombinação genética entre amostras humanas e animais O objetivo deste trabalho foi detectar a presença de rotavírus a partir de 277 amostras fecais de leitões com quadro clínico de diarréia, provenientes dos Estados do Rio Grande do Sul (RS), Santa Catarina (SC), Paraná (PR), Mato Grosso do Sul (MS), Mato Grosso (MT), São Paulo (SP), Rio de Janeiro (RJ) e Minas Gerais (MG) entre os anos de 2009 e 2011 e analisar o perfil eletroforético de migração dos segmentos genômicos bem como diferenças de eletroferótipos nas amostras positivas, pela técnica de eletroforese em gel de poliacrilamida (PAGE). Das 277 amostras fecais diarréicas de leitões analisadas, 25 foram positivas (25/277= 9%). De conformidade com os Estados de origem, foram verificadas as frequências de 20% (1/5) no RS, 11,1% (1/9) em SC, 12,5% (1/8) no PR, 15,3% (6/39) em MS, 14,2% (3/21) em MT, 6,7% (5/74) em SP, 0% (0/7) no RJ e 7% (8/114) em MG. Pela análise da migração eletroforética dos segmentos genômicos, todas as 25 amostras positivas apresentaram perfil eletroforético compatível com o RV-A, tal como a amostra padrão NCDV com migração característica em quatro classes ou agregados [4-2-3- 2]. Foram observadas pequenas diferenças na velocidade de migração de um ou mais segmentos dentro da mesma classe. Estes resultados evidenciam a importância da PAGE como metodologia de diagnóstico e de investigações epidemiológicas nas rotaviroses suínas. / The neonatal diarrhea constitute one of the most important economic and health factors in pig farms either by death or by the aggregate losses to the delay in the development of piglets, prophylaxis and management. Rotaviruses have a prominent role by the rapid spread within the herd, as well as the zoonotic potential, given the likelihood of genetic reassortment or recombination between human and animal samples. The objective of this study was to detect the presence of rotavirus from fecal samples from 277 piglets with clinical cases of diarrhea, from the states of Rio Grande do Sul (RS), Santa Catarina (SC), Paraná (PR), Mato Grosso do Sul (MS), Mato Grosso (MT), São Paulo (SP), Rio de Janeiro (RJ) e Minas Gerais (MG) between the years 2009 and 2011 and to analyze the electrophoretic migration of genomic segments and electropherotype differences in positive samples, by polyacrylamide gel electrophoresis (PAGE) technique. From 277 piglets diarrheal stool samples analyzed, 25 were positive (25/277 = 9%). In accordance with the States of origin, were observed frequencies of 20% (1/5) in the RS, 11.1% (1/9) in SC, 12.5% (1/8) in PR, 15.3 % (6/39) in MS, 14.2% (3/21) in MT, 6.7% (5/74) in SP, 0% (0/7) in Rio de Janeiro and 7% (8/114) in MG. For the analysis of the electrophoretic migration of genome segments, all 25 positive samples showed electrophoretic profile compatible with the RV-A as a standard sample NCDV, showing characteristic fourth class or aggregates [4-2-3-2]. We observed small differences in the migration speed of one or more segments within the same class. These results highlight the importance of PAGE as a method of diagnosis and epidemiological investigations in the porcine rotavirus.

No description available.

Diarrhoeal disease is a major cause of mortality in children in developing countries. It also remains a serious problem among all age groups throughout the world. Whereas studies to determine the epidemiological and aetiological factors of diarrhoeal disease have been reported for other parts of South Africa and the world, as yet no information is available for the Eastern Cape. Therefore this study was undertaken to determine the factors for this area. Enteropathogens were compared for the different ages in the various population groups and, where possible, seasonal and geographical differences were emphasised. A total of 7 278 faecal samples were examined by six laboratories in the Eastern Cape during the period November 1988 to October 1990. Data was recorded noting the age, sex and population group of the patients. The towns selected were Port Elizabeth, Uitenhage, Cradock, Grahamstown and their surrounding areas. The isolation rates for the pathogens studied in the various population groups were compared to those reported in similar studies in other countries. The seasonal incidences of the various selected pathogens were compared with those reported from elsewhere in South Africa. It was thought that the higher temperature of summer may influence the finding in the White population group, while rainfall would play a greater role for the Coloured and Black populations. The geographical distribution of the pathogens emphasised the difference in living conditions between the different population groups. For example a generally higher infestation rate of Helminths occurred in rural areas and in the groups living under poorer conditions. The low isolation rates for certain bacteria and the large percentage of samples from which no pathogens were isolated indicate the need for further research. However, the finding should be valuable for determining Public Health priorities and in the management of outbreaks of diarrhoeal disease.

Hermannia incana Cav. (Sterculiaceae), known as sweet yellow bells, is a medicinal plant used by the people of the Eastern Cape for the treatment of stomach-ache and diarrhoea. It has purgative and diaphoretic effects. It is a prostrate herb with yellow flowers and sparsely hairy and slightly glandular leaves, occurring in grassland and marshes in the Eastern Cape Province of South Africa. Based on the ethnomedical uses of this plant, the research project was designed to evaluate its antidiarrhoeal and toxicological properties. An ethnobotanical study of plants used for the treatment of diarrhoea in the Eastern Cape Province was carried out, using a questionnaire which was administered to herbalists, traditional healers and rural dwellers. This survey indicated a total of 17 plant species from 14 families. Elephantorrhiza elephantine (Burch.) Skeels, Hermannia incana Cav., Pelargonium reniforme Curt., Alepidea amatymbica Eckl. & Zeyh. and Bulbine latifolia (L.f.) Roem. et Schult. were the most frequently mentioned and highly recommended plants for the treatment of diarrhoea by both the traditional healers and rural dwellers. The root, bark and leaves are the common parts of plants used, while decoctions and infusions are the main methods of preparation. The agar dilution method was used to study the antimicrobial activity. The methanol extracts of the plant showed appreciable activity against Gram-positive and Gram-negative bacteria at concentrations ranging from 0.5 to 7.0 mg/ml. The acetone and water extracts of both the leaves and the roots showed moderate activity against Gram positive bacteria and less activity against Gram negative bacteria. All the extracts inhibited the growth of the fungi Aspergillus flavus, Aspergillus niger, and Mucor hiemalis with growth inhibition ranging from 54.31 percent to 96.67 percent at 0.1-10 mg/ml. None of the extracts suppressed the growth of Candida albicans at the maximum concentration (10 mg/ml) tested. iii In the in vivo antidiarrhoeal evaluation using Wistar rats, the aqueous extract at all the doses tested, significantly prolonged the time of induction of diarrhoea and also reduced the frequency of diarrhoeal episodes and fecal parameters (total number, number of wet, fresh and dry weight and water content of the faeces). The percentage inhibition of defecation and intestinal content (enteropooling) were increased in dose dependent manner. The doses also reduced the intestinal transit time of charcoal, masses and volumes of intestinal fluid (gastrointestinal motility). These results are indications of antidiarrhoeal property of H. incana leaf extract with the 600 mg/kg body weight of the extract being the most effective. In the toxicological evaluation using Wistar rats, the oral administration of the extract did not produce any significant effect on the liver and kidney body weight ratios, RBC, HB, PCV, MCV MCH, MCHC, RCDW, WBC, neutrophils, monocytes and basophils cholesterol, triacylglycerol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and atherogenic index. The extract also did not affect the levels of sodium, potassium, chloride, inorganic phosphorus, urea, creatinine, total protein, globulin, albumin, total and conjugated bilirubin. The activities of alkaline phosphatase, gamma glutamyl transferase and alanine aminotransaminase in the serum were increased by the extract whereas aspartate aminotransaminase was decreased. The levels of LUC, platelets, lymphocytes and eosinophils were significantly affected at 600 mg/kg body weight. The available evidence in this study suggests that the extract of H. incana leaf is mild, parameter and dose specific. The structure and distribution of foliar appendages on the leaves of this plant were investigated with the JEOL (JSM-6390LV) scanning electron microscope (SEM). Both glandular and non-glandular trichomes were observed. Long stalked glandular trichomes were present on both the abaxial and adaxial surfaces while short stalked glandular trichomes were present only on the adaxial surface. Glandular trichomes were capitate while nonglandular trichomes were stellate with many arms. Energy dispersive X-ray spectroscopyiv SEM showed that Al, Ca, K, Na, Ti and Si were the major constituents of the crystals analyzed from the leaf surfaces. The phytochemical screening of H. incana revealed the presence of bioactive antidiarrhoeal agents such as alkaloids, tannins, saponins, phenolics, triterpenes, cardiac glycosides, flavonoids, cardenolides and dienolides. Two flavonoids, epicatechin and 3, 5, 7, 2’ tetra-hydroxy flavone-3- O--D-glucopyranoside were isolated from the leaves of the plant through bio-active guided fractionation. Both these compounds were screened against diarrhoea causative organisms (Echerichia coli, Shigella flexneri, Bacillus cereus and Staphylococcus aureus) and exhibiting minimum inhibitory concentrations ranging from 12.5 to 100 μg/ml. The findings from this research have generally justified the traditional use of this plant for the treatment of diarrhoea in this province.

Introduction: Diarrhea remains one of the main causes of morbidity and mortality in children under five years of age especially in low-income countries. In Peru, epidemiological reports about enteropathogens related to acute diarrhea are scarce in rural areas. The aim of this study was to describe the etiology, epidemiology, and clinical characteristics of the principal causes of acute infectious diarrhea in in a northern rural region of Peru. Methodology: A prospective study was conducted from January 2011 to December 2012 to describe the main pathogens causing acute diarrhea using PCR assay. Results: A total of 117 children diagnosed with acute diarrhea were included in the study. A single etiological agent was identified in 41.03% of samples, being rotavirus followed by norovirus and Shigella. Co-infections containing virus and bacteria were found in 22.22% of samples. Vomiting was most commonly found symptoms in 58.97% cases followed by fever (54.70%). Malnutrition was detected in 14.53% of the children. Conclusions: High prevalence of rotavirus, as well as adenovirus and norovirus, was observed in the present study. Shigella was the most common bacteria found in acute diarrhea in the area. The implementation of a better surveillance system is mandatory in order to identify the principal etiologies of gastroenteritis in the rural areas of Peru and to develop of better prevention strategies and reduce diarrhea-associated mortalities.

aEPEC é capaz de causar lesão A/E, provocada por proteínas codificadas na região LEE. Foi realizada a análise estrutural e funcional da região LEE de amostras de aEPEC que expressam os padrões ALL, AA e AD, e amostra não aderente (NA). O padrão de adesão característico e capacidade de causar a lesão A/E foram investigados em células epiteliais. As amostras mantiveram o padrão de adesão independentemente da origem da linhagem celular. A lesão A/E foi detectada em algumas linhagens celulares após o contato com as amostras ALL e AD. A presença da região LEE foi detectada intacta e ensaios de PCR em tempo real, microarray e imunodetecção, mostrando a funcionalidade da mesma em todas as amostras. Um plasmídio que expressa a proteína EspFu foi introduzido em todas as 4 amostras, demonstrando não influenciar nos padrões de adesão e nem na capacidade de causar a lesão A/E nas amostras ALL, AA e AD. Mas, a amostra NA expressou o padrão ALL e foi capaz de causar a lesão A/E. Assim, EspFu desempenhou papel na adesão celular além do estabelecimento da lesão A/E in vitro. / aEPEC is capable to cause A/E lesion, triggered by proteins encoded by LEE region. We analyzed structurally and functionally the LEE region of aEPEC strains displaying LAL, AA, DA, and one nonadherent (NA) strain. The adherence characteristics and ability to cause A/E were investigated in epithelial cells. The displayed adherence patterns were independent of the cell line origin. A/E lesion was detected in some cellular lines after contact only with ALL- and AD-strains. LEE region presence was detected intact and real time PCR, microarray and immunodetection, in all samples tested. An EspFu-expressing plasmid was introduced in all strains, demonstrating no influence of this protein neither in the adherence patterns nor in the capacity to cause A/E of the LAL-, AA- and DA-strains. But, NA-strain expressed the LAL pattern and was able to cause A/E. Therefore, EspFu was shown to play a role in cell adhesion in addition to the establishment of the A/E lesion in vitro.

Hajj, the annual Muslim pilgrimage to Mecca, Saudi Arabia is a unique mass gathering event that attracts approximately 3 million pilgrims from around the globe. This diverse pilgrim population coupled with the nature of the performed activities raise major public health concerns in the host country with potential global implications. Although gastroenteritis and diarrhea are common among the pilgrims performing Hajj, the microbial etiologies of these infections are still unknown. We used molecular and antigenic approaches to identify the main pathogens associated with Hajj diarrhea. 544 fecal samples from pilgrims suffering from diarrhea whilst performing Hajj during three consecutive seasons (2011-2013) and 99 control samples from 2011 were screened for 16 pathogens that include bacterial, parasitic and viral etiologies that are commonly associated with diarrheal infections. At least one of the screened pathogens could be detected in 42% (n=228) of the samples from the diarrheal cases. Bacteria were the main agents detected in 83% (n=189) of the positive samples, followed by viral and parasitic agents detected in 6% (n=14) and 5% (n=12) respectively. We have also standardized a 16S-based metagenomic approach to identify the gut microbiome in diarrheal cases and non-diarrheal controls in 76 samples. Also, we have standardized a shotgun metagenomics protocol for the direct characterization (diagnosis) of enteric pathogens without cultivation. This approach was used successfully to identify viral (adenovirus) and bacterial causes of Enterotoxigenic E. coli diarrhea from Hajj samples. The findings in this study fill in clear gaps in our knowledge of the etiologies associated with diarrheal infections during Hajj. Foodborne bacteria were the major contributors to Hajj-diarrheal infections. This was coupled with the increased incidences of antimicrobial resistance loci associated with the identified bacteria. These findings would help the public health policy makers to develop and introduce appropriate public health measures to improve the food safety during Hajj.

INTRODUCTION: Small intestinal bacterial overgrowth refers to the proliferation of abnormal numbers and types of microorganisms in the lumen of the proximal bowel. Bacterial overgrowth has been implicated as a possible factor in prolonging some episodes of infantile gastroenteritis. This thesis examines 2 different aspects of the duodenal flora of infants with gastroenteritis, and has therefore been divided into 2 separate studies. CARBOHYDRATE STUDY: Objective: To test the hypothesis that during a diarrhoeal episode the presence of malabsorbed carbohydrate in the duodenal lumen acts as a factor promoting bacterial proliferation. Patients and methods: Infants admitted to the rehydration ward with acute gastroenteritis were selected for study if they fulfilled various criteria in terms of age, nutritional status, previous diarrhoeal episodes and antibiotic administration. They were admitted to the research ward. Weights were measured and if they had severe diarrhoea (≥ 30g/kg) were included in the study. Twenty patients were entered into the study. On admission into the trial the first duodenal intubation was done to measure the duodenal flora quantitatively and qualitatively. Thereafter the patients were assigned on an alternate basis to one of 2 groups. One group (carbohydrate-containing group) received a soy-based infant formula containing carbohydrates (Isomil, Ross). The other group (carbohydrate-free group) received an identical milk but from which all carbohydrate had been omitted (Ross CHO-free). To these infants carbohydrate was given intravenously. Stool output was measured daily. After 3 days of the respective diets the duodenal flora was re-examined. Results: Longitudinal analysis of the duodenal flora of the carbohydrate-containing group showed a small decrease in the number of bacterial isolates and in their magnitude. The duodenal flora of the carbohydrate-free group was virtually unchanged. Comparing the duodenal bacteriology of the groups the only significant difference was that the number of isolates and the magnitude of Haemophilus was greater in the carbohydrate-free group- (p < 0.05). The diarrhoea resolved in 5 patients: 2 in the carbohydrate-containing and 3 in the carbohydrate-free group. Conclusions: The lack of difference in the response of the duodenal flora between the two groups studied suggests that the presence of carbohydrates in the lumen is not important in encouraging the growth of bacteria in that site. The possible causes for an increase in Haemophilus numbers in the carbohydrate-free group are discussed. BOWEL COCKTAIL STUDY: Objective: Small intestinal bacterial overgrowth has been proposed as a cause of progression of acute diarrhoeal episodes to persistence. The "bowel cocktail", a combination of oral gentamicin and cholestyramine, has been shown to be effective in terminating episodes of persistent diarrhoea. It has been postulated to work by eradicating small intestinal bacterial overgrowth, but its mode of action is not known. The objective of this study was to examine the changes in the duodenal flora associated with administration of the bowel cocktail in order to elucidate its possible mechanism or mechanisms of action. Patients and methods: The study group comprised 15 patients. Fourteen were infants from the carbohydrate study who had ongoing diarrhoea. The remaining infant (the "late entry") was selected from the rehydration ward. Severe diarrhoea, as defined by a stool output equal to or greater than 30g/kg/day, was a pre-requisite for entry into the study. The investigation involved 2 duodenal intubations for microbiological analysis of the duodenal fluid. After the first intubation (which was the second intubation for the 14 infants who had been in the carbohydrate study) the bowel cocktail was administered. This comprised a 3-day course of oral gentamicin and 5 days of oral cholestyramine. Forty-eight hours after the start of therapy the duodenal bacteriology was repeated. The patient management was the same as during the carbohydrate study and the feeding regimen of the infants was not altered. The study ended immediately after completion of the bowel cocktail course. Results: Administration of the bowel cocktail was associated with a decreased stool output in all patients. Bacteriological analysis of the duodenal flora after this treatment showed a statistically significant decrease in the total microbial count, the aerobic microbial fraction and the Enterobacteriaceal fraction. On analysis of the bacterial genera a significant decrease was noted in Neisseria, Haemophilus, and aerobic lactobacilli. Analysis of individual patients' duodenal fluid bacteriology in conjunction with the stool bacteriology results before administration of the bowel cocktail often provided an explanation as to the possible aetiology of the diarrhoea and its resolution by therapy. Conclusions: Small intestinal bacterial overgrowth, in the accepted sense of a luxuriant flora teeming with faecal organisms, did not appear to be a feature of the patients in this study. The total bacterial count was only slightly above the accepted upper limit of normal. Although the decrease in the number of Enterobacteriaceae could possibly be interpreted in the context of bacterial overgrowth, a study of the individual patients' duodenal flora shows that these microorganisms were more likely to be acting as specific enteric pathogens. It is concluded that small intestinal bacterial overgrowth, as currently defined, is not an important cause of persistent diarrhoea. The efficacy of the bowel cocktail is more likely to reside in its ability to eradicate specific enteric pathogens. The author ends by questioning the validity of the whole concept of small intestinal bacterial overgrowth.