Phenotypic and genotypic study of biofilm formation in Enterococci isolated from urinary tract infections

BACKGROUND

Urinary tract infection (UTI) is one of the most frequent types of nosocomial and community acquired infections in humans. Management of multidrug-resistant Enterococci UTI due to the limited therapeutic options is a great challenge for physicians and clinical microbiologists. The role of bacterial biofilms in recurrent urinary tract infections and antimicrobial resistance has great importance for public health. The aim of this study was to investigate the antibiotic susceptibility pattern as well as the phenotypic and genotypic biofilm formation ability of Enterococci isolates from patients with UTI.

METHODS

A total of 57 isolates of Enterococci were collected from patients with UTI. Enterococcus species were identified using conventional microbiological methods. The antibiotic susceptibility patterns of the isolates were determined by the Kirby-Bauer disk-diffusion. The Modified Congo red agar (MCRA) and Microtiter plate methods used to assess the ability of biofilm formation. All enterococcal isolates were examined for determination of biofilm-related genes, esp, asa1 and ebpR using PCR method.

RESULTS

Of 57 enterococcal isolates, 85.9% were recognized as E. faecalis and 14.1% of them were E. faecium. According to our results, linezolid, chloramphenicol and nitrofurantoin were the most effective agents against Enterococcus species. Overall, 26.5% of E. faecalis and 75% of E. faecium isolates were biofilm producers, respectively. Resistance to some antibiotics including penicillin G, ampicillin, vancomycin, nitrofurantoin and chloramphenicol, and ciprofloxacin was significantly higher among biofilm producers than non-biofilm producers Enterococci. The esp, asa1 and ebpR genes were present in 84.2%, 91.2% and 100% isolates. In this study, there was not a significant relationship between presence of these genes and biofilm formation.

CONCLUSION

Our findings reinforce the role of biofilm formation in resistance to antimicrobial agents. Quinupristin/dalfopristin, tetracycline and rifampin may be used as an effective treatment for UTI caused by biofilm producers Enterococci. Our results suggest that biofilm formation is complex and depends on various factors but not just esp, asa1 and ebpR genes in Enterococcus strains.

Comparison of clinical features and pathologic findings in fatal cases of typhoid fever during the initial and later stages of the disease

This study was undertaken to correlate the clinical features and pathologic changes noted during the initial and later stages of fatal typhoid illness. Five cases who died during the initial stage of the illness (< 2 weeks from onset) had altered mental status, tachypnea, and tachycardia. Three had shock and elevation of serum creatinine values. Autopsies of all five revealed hyperplastic Peyer's patches, features of adult respiratory distress syndrome, and megakaryocytosis. Five other cases died during the later stage of the illness (> or = 2 weeks after onset). They had a left shift in peripheral blood leukocyte count. Autopsies revealed deep ileal ulcerations with or without perforation and peritonitis and intercurrent pneumonia. Three of them had disseminated intravascular coagulation. Further studies are warranted to understand the mediators of shock and tissue injuries during the initial period of the illness.

Erythromycin and trimethoprim-sulphamethoxazole in the treatment of cholera in children

To evaluate the efficacy of erythromycin and trimethoprim-sulphamethoxazole (TMP-SMX) in the treatment of cholera in children aged 1-8 years, a randomised clinical trial was conducted at a diarrhoea treatment centre in Bangladesh from December 1991 to June 1992. Fifteen children received erythromycin, 50 mg/kg per day, in four equally divided doses, 18 children received 10 mg/kg per day of trimethoprim and 50 mg/kg per day of sulphamethoxazole in two equally divided doses (12 hourly) for five days, and 15 children received no antibiotic; children in all three groups received intravenous cholera saline for severe dehydration and for mild to moderate dehydration, a rice-based oral rehydration solution. The mean stool volumes in mL/kg body weight in the two treatment groups were less than that of the control group, and there were no significant differences in stool volume among the two treatment groups. However, 67% of the children in the erythromycin group and 82% in the TMP-SMX group recovered within 72 hours compared to 33% in the control group (p < 0.01). Similarly, the bacteriological cures were 80% in the erythromycin group and 83% in the TMP-SMX group compared to only 27% in the control group (p < 0.001). These results confirm that both erythromycin and trimethoprim-sulphamethoxazole are effective antimicrobials in the treatment of cholera. These drugs are of value specially in younger children in whom tetracycline is contraindicated or when the infecting Vibrio cholerae are resistant to tetracycline.

Moraxella septicemia in children with diarrheal disease

We report 10 cases of Moraxella septicemia associated with diarrheal disease. Their clinical presentations and outcomes are discussed. Recognition of the pathogenicity of these microorganisms in appropriate clinical setting should result in prompt and specific therapy.

Development and evaluation of co-agglutination test to detect rotavirus antigens in stools of patients with diarrhoea

Rotavirus is the most common cause of acute diarrhoea in infants and children in both the developed and developing countries including Bangladesh. Information about rotavirus diarrhoea in Bangladesh is insufficient primarily due to the lack of diagnostic facilities due to the high cost of reagents and equipment and lack of skilled personnel. A simple, suitable and less costly technique of co-agglutination test using protein-A secreting staphylococci was developed and evaluated against a commercially available ELISA kit to detect rotavirus antigen in stools of patients with diarrhoea. Staphylococcus cowan strain 1 was grown and coated with rabbit antisera raised against RV5 and SA11 rotavirus strains. The antibody-coated staphylococci were agglutinated specifically by rotavirus present in faecal samples within one or two minutes. A total of 1332 stool specimens were tested by co-agglutination and ELISA, of which 210 (15.77%) were positive by ELISA and 276 (20.72%) by co-agglutination test. Compared to ELISA, sensitivity of co-agglutination test was 76.19%, specificity 89.66% and predictive values of a positive and a negative test were 57.97% and 95.26% respectively. The results indicate that the co-agglutination test is a simple and suitable technique for rapid screening of rotavirus infection which could be adopted in clinical practice.

Effect of antimicrobial (nalidixic acid) therapy in shigellosis and predictive values of outcome variables in patients susceptible or resistant to it

We observed the clinical features and results of simple laboratory tests on stools of 33 children with bacteriologically proven shigellosis to identify features that could be used to assess the effectiveness of antimicrobial therapy. Persistence of fever (rectal temperature > 37.8 degrees C), abdominal pain/tenderness and anorexia on days 3 and 5 were significantly more common (P < 0.001) among children who received an antimicrobial to which the infecting Shigella was resistant. Similarly, a significantly higher number of children treated with an ineffective antimicrobial had faecal leucocytes of > 50/high power microscopic field (HPF), erythrocytes of > 50/HPF and macrophages of > 5/HPF on study day 5. The best predictors of ineffective antimicrobial therapy on days 3 and 5 of treatment were fever, presence of blood by naked eye examination of stool, and minimum change in stool frequencies. These observations suggest that by careful follow-up of clinical features and simple laboratory tests, such as stool microscopic examinations, it is possible to identify patients unlikely to respond to initial therapy by 72 hours permitting the start of alternative antimicrobial treatment. This may be of great help where stool culture and sensitivity facilities for Shigella spp. are not available.

Double-blind comparison of oral gentamicin and nalidixic acid in the treatment of acute shigellosis in children

To compare the efficacy of oral gentamicin with nalidixic acid in the treatment of acute shigellosis, we studied, in a double blind-trial, 79 comparable children with bloody diarrhoea of less than 72 h duration. Of them Shigella spp. were isolated in 71 patients. Patients were randomly assigned to receive either gentamicin 30 mg/kg/day or nalidixic acid 60 mg/kg/day, both given orally in four equal doses for 5 days. Stool frequency differed significantly between the groups from day two until completion of the study. Treatment failure was observed in 14 (42 per cent) patients receiving oral gentamicin compared to none of those with nalidixic acid-sensitive strains of Shigella spp. (P = 0.0002). Although all the shigella isolates were sensitive to gentamicin in vitro, 19 (58 per cent) patients on gentamicin therapy failed to eliminate shigella organisms from stool, compared to none in the nalidixic acid treated group infected with nalidixic acid-sensitive Shigella spp. (P < 0.001). One patient in each group had a bacteriological relapse. We conclude that gentamicin given orally was therapeutically ineffective in the treatment of acute shigellosis.

Enteric protein loss and intestinal permeability changes in children during acute shigellosis and after recovery: effect of zinc supplementation

The effect of zinc supplementation on intestinal permeability changes and protein loss was studied in 32 children aged between 1 and 12 years during bouts of acute shigellosis and after recovery. An intestinal permeability test and then a 48 hour balance study were performed on all patients. They were then blindly assigned to receive vitamin B syrup either with or without zinc acetate (15 mg/kg per day) for a month. All patients received a five day course of nalidixic acid. The balance study was repeated during convalescence and follow up, but a permeability test was done only at follow up after one month. Intestinal permeability, expressed as a urinary lactulose:mannitol excretion ratio, improved significantly (p = 0.001) along with a significant increase (p = 0.005) in mannitol excretion in the zinc supplemented children, suggesting a resolution of small bowel mucosal damage. The latter was associated with a higher coefficient of nitrogen absorption (p = 0.03), suggesting a possible role of zinc in the treatment of shigellosis. Enteric protein loss, as assessed by faecal alpha 1 antitrypsin clearance, was not influenced by zinc supplementation.

Comparison of pivmecillinam and nalidixic acid in the treatment of acute shigellosis in children

The efficacy of oral pivmecillinam was compared with nalidixic acid in the treatment of acute shigellosis in children 1-8 years of age. In a double-blind trial we studied 80 comparable children with bloody diarrhoea of less than 3 days' duration. Shigella spp. was isolated in 71 children. Patients were randomly assigned to receive either pivmecillinam, 50 mg/kg.day, or nalidixic acid, 60 mg/kg.day, both given orally for 5 days. The stool frequency decreased progressively in both treatment groups. Nalidixic acid failed to eradicate Shigella species in 10 patients, compared with three in the pivmecillinam group (p = 0.04). Similarly, clinical failure was observed in 11 of 37 patients receiving nalidixic acid and in 2 of 26 patients infected with nalidixic acid-susceptible strains as against none in the group receiving pivmecillinam. The results suggest that pivmecillinam given orally was, in fact, more effective than nalidixic acid in the treatment of acute shigellosis in children, particularly when the resistant strains are taken into account.

Management of acute diarrhoea in diabetic patients using oral rehydration solutions containing glucose, rice, or glycine

OBJECTIVE

To assess the risk of hyperglycaemia with two standard oral rehydration solutions that contain carbohydrate compared with a carbohydrate free solution during rehydration of diabetic patients with acute diarrhoea.

DESIGN

Prospective randomised allocation to one of three oral rehydration solutions (World Health Organisation (glucose), rice, or glycine) groups after admission to hospital with acute diarrhoea.

SETTING

Dhaka hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh.

SUBJECTS

45 diabetic patients aged between 15 and 60 who had had diarrhoea for fewer than three days on admission.

MAIN OUTCOME MEASURES

Fluctuation of blood glucose concentrations measured three times a day, daily stool output, and time taken for recovery from diarrhoea.

RESULTS

There were no significant differences in blood glucose concentrations, stool output, and duration of recovery from diarrhoea among the three groups.

CONCLUSIONS

Oral rehydration solutions containing glucose, rice powder, or glycine can be safely administered to diabetic patients with acute diarrhoea and some dehydration.

Characterisation of Plesiomonas shigelloides strains that share type-specific antigen with Shigella flexneri 6 and common group 1 antigen with Shigella flexneri spp. and Shigella dysenteriae 1

Three strains of Plesiomonas shigelloides isolated from patients with diarrhoea were agglutinated with Shigella flexneri 6 antiserum in slide and tube tests. All the strains were also agglutinated with a monoclonal antibody to the common group 1 antigen shared between S. flexneri serotypes and S. dysenteriae type 1. Further studies with one strain also showed sharing of antigenicity in an enzyme-linked immunosorbent assay. The results suggest that the strains share type-specific antigen with S. flexneri 6 and the common group 1 antigen with S. flexneri serotypes and S. dysenteriae 1. The sharing of antigens may have implications for cross-protection. One strain adhered to HEp-2 cell monolayers. None of the strains contained high mol. wt plasmids and there was no sequence homology with the invasiveness plasmid of Shigella spp. in DNA probe hybridisation. They were susceptible to the commonly used antibiotics. However, they possessed four other virulence-associated properties of Shigella spp. that included Congo-red binding, hydrophobicity, toxicity to HeLa cells and HEp-2 cell invasiveness (although they gave negative results in the Sereny test for invasiveness). These data suggest that the three unique strains might be considered pathogenic. Studies in animal models and human volunteers would be necessary to establish their pathogenic potential.

Bacteraemia and meningitis among hospital patients with diarrhoea

To characterize bacteraemia and meningitis in diarrhoeal patients, the records of 3395 blood cultures and 120 cerebrospinal fluid (CSF) cultures from 6132 patients admitted with diarrhoea to the Clinical Research Centre of the International Centre for Diarrhoeal Disease Research, Bangladesh during 1989 were analysed. Microorganisms were isolated from 12% (417 of 3395) of blood cultures and 9% (11 of 120) of CSF cultures. Children below 5 years of age represented 80% of all patients who had blood cultures and 82% of those who had CSF cultures made. The nutritional status was significantly lower in patients who had positive blood cultures than in those who had negative cultures. 23% (97 of 417) of patients with positive blood cultures and 45% (5 of 11) with positive CSF cultures died. Deaths occurred twice as often among patients who had organisms isolated than among those who had no organisms isolated from blood cultures. The organisms isolated from blood cultures which predicted most deaths were Pseudomonas aeruginosa, Neisseria meningitidis, Escherichia coli and Klebsiella sp., and they were multiresistant. We conclude that bacteraemia and meningitis remain serious complications associated with diarrhoea, especially in malnourished children; the therapeutic problem is further complicated by multiple drug resistance of the isolates.

Maternal nutritional status as a determinant of child health

To determine the relationship between the nutritional status of the mother and that of the child, 339 children aged 3-36 months and their mothers in two urban hospitals and a community out-patient clinic, were studied. The weight and height of both children and their mothers were measured, and body mass indices (BMI) of the mothers were calculated. Socio-economic status, maternal educational level, and dietary information were recorded in a predesigned questionnaire. The child's nutritional status, as indicated by weight for age (as a percentage of NCHS median), was associated with the body mass index of the mother (P < 0.001), socio-economic status of the family (P < 0.001), and breastfeeding status of the child (P < 0.005) in a multivariate analysis after adjusting for several prognostic factors. The results indicate that maternal nutritional status is a proximate determinant of a child's nutritional status and should be considered in programmes aiming at improving child health.

Persistent diarrhoea: factors affecting absorption and clinical prognosis during management with a rice-based diet

Twenty-six persistent diarrhoea patients aged 4 to 18 months were treated with a diet prepared with rice powder, soya oil, glucose, egg white and water. Absorption of macronutrients was estimated in a 72 h balance study and clinical response was examined during one week of dietary treatment. Nutrient absorption was compared with that of 25 healthy age-matched controls treated with the same diet. Twenty-one patients (81%) recovered from diarrhoea within seven days. Absorption of nutrients was significantly reduced among the persistent diarrhoea patients. More malnourished patients had a significantly reduced absorption of nutrients except carbohydrate and an increased severity and longer duration of diarrhoea. Total gut transit time had significant association with nutrient absorption in the persistent diarrhoea patients. The period of recovery negatively correlated with coefficient of absorption and positively with initial stool weight. Failure to recover was associated with severity of diarrhoea and systemic infection. The study indicates that nutrient absorption is significantly reduced in patients with persistent diarrhoea and nutritional status, and that initial purging rate and intestinal hurry are significantly related to the prognosis and nutrient absorption.

Lack of therapeutic efficacy of vitamin A for non-cholera, watery diarrhoea in Bangladeshi children

Vitamin A deficiency has been postulated to increase childhood mortality, possibly through increasing the severity and case-fatality of infectious diseases like diarrhoea. A clinical trial was conducted to measure the effect of vitamin A therapy on the severity and duration of acute episodes of non-cholera, watery diarrhoea; 83 children with less than 48 h of illness were randomized to receive vitamin A (200,000 IU of retinyl palmitate) orally or placebo during hospitalization at the International Centre for Diarrhoeal Disease Research in Bangladesh. The patients were similar initially with regard to age, nutritional status and severity of diarrhoea prior to admission. No adverse effects of vitamin A were detected. During hospitalization there were no differences between groups in duration of illness or stool output. Thus, vitamin A can be given safely during diarrhoeal illness to augment hepatic reserves and possibly provide a beneficial effect in regard to subsequent episodes of diarrhoea and other infections, but this supplementation should not be expected to have a therapeutic effect on a current episode.

Campylobacter jejuni bacteraemia in children with diarrhoea in Bangladesh: report of six cases

Campylobacter jejuni was isolated from blood cultures from 6 of 6,275 diarrhoeal children seeking treatment at the Clinical Research Centre of the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) between April 1989 and December 1990. The clinical records of these 6 children were reviewed. All children were male; 5 were less than 1-year old and were severely malnourished. Five patients presented with watery diarrhoea and one with bloody diarrhoea. Two children died in the hospital. All strains of Campylobacter isolated from the 6 children were negative for cell invasive properties as tested by the Sereny test. Of the two strains tested for serum bactericidal activity, one strain was serum sensitive (growth inhibition), and the other resistant. The ability of C. jejuni to cause bacteraemia suggests that the organisms may be responsible for diarrhoeal diseases especially in young and malnourished children. An early attempt to detect Campylobacter and start effective antimicrobial therapy is indicated.

Characterization of Aeromonas caviae antigens which cross-react with Shigella boydii 5

Live and boiled cells of 16 strains of Aeromonas caviae, isolated from patients with diarrhea, agglutinated with Shigella boydii 5 antiserum in a slide test. Further studies with seven selected strains showed agglutination with boiled cells in a tube test. Lipopolysaccharide antigen extracted from one of these strains cross-reacted with S. boydii 5 in enzyme-linked immunosorbent assay and immunoblot studies. Either all or the majority of the seven strains possessed properties deemed to be diarrheagenic.

DNA probe analysis of diarrhoeagenic Escherichia coli: detection of EAF-positive isolates of traditional enteropathogenic E. coli serotypes among Bangladeshi paediatric diarrhoea patients

Escherichia coli isolates from all surveillance patients less than or equal to 20 months of age seen for diarrhoea at the Dhaka Clinical Treatment Facility of the International Centre for Diarrhoeal Disease Research, Bangladesh between March 1 and August 31, 1988, were collected and hybridized with DNA probes to assess the potential importance of diarrhoeagenic E. coli among paediatric patients in Bangladesh. Of 396 patients evaluated, 18% were infected with enteropathogenic E. coli (EPEC) adherence factor (EAF)-positive E. coli, 23% were infected with enterotoxigenic E. coli (ETEC), 9% were infected with Shiga-like toxin-positive E. coli, and 13% were infected with diffuse adhesiveness-positive E. coli. None were infected with enteroinvasive E. coli. Ten percent of patients were colonized with more than one type of potential diarrhoeagenic E. coli. The majority of EAF-positive isolates were of traditional EPEC O:H serotypes. Although this was not a case-control study, the large number of EPEC and ETEC, which are recognized enteric pathogens, suggests these organisms are important causes of diarrhoeal diseases in this pediatric population.

A comparative study of specific gene probes and standard bioassays to identify diarrhoeagenic Escherichia coli in paediatric patients with diarrhoea in Bangladesh

We compared the usefulness of gene probes with standard bioassays to identify diarrhoeagenic Escherichia coli amongst isolates from Bangladeshi children under 1 year of age with diarrhoea. E. coli isolates were analysed with specific gene probes for localised adhesiveness (LA), diffuse adhesiveness (DA), heat-labile toxin (LT), heat-stable toxin (ST), Shiga-like toxins (SLT I and SLT II), and enteroinvasiveness, and in bioassays for production of enterotoxins and cytotoxins, and for cell adherence. With 1136 isolates from 387 patients, there was general agreement between the two assay methods. When there was disparity, gene-probe-positive isolates gave negative results in the corresponding bioassay. In the HeLa cell adherence assay, 94% of the LA probe-positive isolates and 91.6% of the DA probe-positive isolates gave positive bioassay results for LA and DA respectively. Thirty-six of 39 LT probe-positive isolates and 73 of 86 ST probe-positive isolates gave positive results in the bioassays. Of 28 isolates that gave negative results in the suckling mouse assay but were initially positive with the probe for ST, 15 were later found to hybridize with the cloning vector for the ST probe. Addition of denatured vector DNA at a concentration of 10 micrograms/ml in the hybridisation solution eliminated these false positive results. None of the other probe-positive isolates hybridised with any of the cloning vectors used. The DNA hybridisation assay appeared to be a convenient alternative to bioassays for screening large numbers of isolates in epidemiological investigation.

Enteroaggregative Escherichia coli infections in Bangladeshi children: clinical and microbiological features

Escherichia coli isolated from 389 children, less than 1-year of age with diarrhoea, were analyzed for the presence of Enteroaggregative E. coli (EAggEC) by their pattern of adherence to HeLa cells. EAggEC were isolated from 58 (14.8%) children either as a sole pathogen or in combination with other enteric pathogens. In 60% of these children EAggEC infection occurred in the second half of infancy (7-12 m). Thirty-eight of 47 children having EAggEC as a sole pathogen had watery diarrhoea along with vomiting (87%) and dehydration (74%). In contrast, 9 of the 47 cases had mucoid diarrhoea with infrequent vomiting and dehydration and frequent abdominal pain. Children infected with EAggEC were successfully rehydrated with oral rehydration solution (ORS) alone. Seventy-one percent of the EAggEC strains were resistant to more than three antibiotics. It was evident by phage pattern that various EAggEC strains were present in the population. The results indicated that infections with EAggEC may have a role in the development of diarrhoea among children less than 1-year of age in Bangladesh.

Prognostic indicators and risk factors for increased duration of acute diarrhoea and for persistent diarrhoea in children

To identify the prognostic indicators and risk factors for increased duration of acute diarrhoea and for occurrence of persistent diarrhoea (i.e. acute episodes lasting longer than 14 days) in children under three years, a systematic sample (3690) of patients attending a large treatment centre in Bangladesh was analysed using multiple regression, logistic regression and stratified (Mantel-Haenszel) analysis. Significant prognostic indicators or risk factors for increase in duration of acute diarrhoea, after adjusting for confounders, include bloody or mucoid diarrhoea, concomitant signs of chest infection, presence of vitamin A deficiency signs, decreased weight for age, routine use of contaminated surface water, lack of breastfeeding and increasing age; presence of rotavirus or enterotoxigenic Escherichia coli or Vibrio cholerae 01 in stool had negative association. In logistic regression and stratified analysis these factors, except for lack of breastfeeding and age, were also found to be risk factors or prognostic indicators of persistent diarrhoea. Policy implications of these findings for programmes to reduce morbidity and mortality from persistent diarrhoea include development of effective vaccines against dysentery-causing Shigella, programmes to prevent vitamin A deficiency, protein energy malnutrition and acute respiratory infections in children, and long-term programmes to provide clean water for all day-to-day needs.

Prostacyclin concentrations in haemolytic uraemic syndrome after acute shigellosis in children

The role of prostacyclin in the pathogenesis of haemolytic uraemic syndrome was evaluated in 11 children with acute shigellosis. Plasma concentrations of 6-keto prostaglandin, F1 alpha, a stable metabolite of prostacyclin, were measured by radioimmunoassay during acute illness, early convalescence, and after clinical recovery. Its concentration was low during acute illness in each patient, returning to normal concentrations or above at the time of the last sample. These results suggest that plasma prostacyclin may be involved in the development of the syndrome.

Complications and outcome of disease in patients admitted to the intensive care unit of a diarrhoeal diseases hospital in Bangladesh

A retrospective analysis of the medical records of 1970 patients admitted to the intensive care unit of the Clinical Research Centre in Dhaka, Bangladesh was made, to identify various complications and outcome. All patients were admitted with a history of diarrhoea. Children under 5 years old comprised 90% of these patients. 75% of these seriously ill patients recovered; 21% died; the remaining 4% were referred to other facilities for specialized treatment or left the hospital against advice. The principal causes of death were recorded as septicaemia (79%) and pneumonia (28%); multiple conditions contributing to the death were present in 90% of patients. None of the 405 deaths could be attributed to dehydration. Severe malnutrition was noted as an associated underlying disorder contributing to the death of 74% of the children. Recognition of these complications or illnesses in seriously ill diarrhoeal patients, and their timely and energetic management, are vital in achieving a low hospital mortality.

Serum ferritin and cholera. A prospective study

An association has been shown between iron deficiency and a low gastric acidity while the latter is known to increase susceptibility to cholera. This study was undertaken to ascertain whether iron deficiency is a risk factor for contracting cholera. The subjects were 60 adult males-30 with cholera admitted to ICDDR,B and 30 controls matched for age, sex and socio-economic status from the same household or immediate neighbourhood of the index case. Fingerstick blood was taken from all subjects to estimate the haematocrit, and serum ferritin concentration by an ELISA. The mean ferritin level of the study group was 38.7 ng/100 ml, in the controls. There was a significant difference in the serum ferritin level between the groups (P less than 0.005), Wilcoxon Sign Rank test for matched pairs suggesting that cholera patients tend to have lower serum ferritin concentration. Further prospective studies are required to define the possible association between iron deficiency and cholera more accurately.

Randomised double blind trial of single dose doxycycline for treating cholera in adults

OBJECTIVE

To compare the efficacy of a single dose of doxycycline (200 or 300 mg) with the standard multiple doses of tetracycline in patients with cholera.

DESIGN

Randomised double blind controlled trial. Patients were given a single 200 mg dose of doxycycline, a single 300 mg dose of doxycycline, or multiple doses of tetracycline (500 mg, six hourly intervals).

SETTING

Hospital in Bangladesh treating diarrhoea.

PATIENTS

261 Patients aged over 15 admitted to the hospital with severe dehydration due to acute watery diarrhoea associated with Vibrio cholerae. All vibrios isolated from the stools and rectal swabs of patients, including those patients with prolonged excretion of vibrios, were sensitive to tetracycline. The stools of all patients at admission were negative for shigella and salmonella.

INTERVENTIONS

All patients received rapid intravenous acetate solution for the first four hours after admission to hospital. They were then entered in the study and randomised. Oral rehydration was started immediately after the intravenous treatment. If signs of severe dehydration reappeared during oral treatment patients were given rapid intravenous acetate solution until dehydration was fully corrected.

MAIN OUTCOME MEASURES

Stool output in first 24 hours and till diarrhoea stopped, total intake of oral rehydration fluid, duration of diarrhoea, and excretion of vibrio after receiving antibiotic treatment.

RESULTS

The median stool outputs during the first 24 hours (275 ml/kg body weight) and till diarrhoea stopped (296 ml/kg body weight) were significantly higher in patients receiving 200 mg doxycycline as a single dose than in patients receiving either standard tetracycline (242 ml/kg body weight and 254 ml/kg body weight) or 300 mg doxycycline (226 ml/kg body weight and 255 ml/kg body weight). Similarly, median consumption of oral rehydration solution (18.45 l) was significantly higher in patients receiving 200 mg doxycycline than in patients receiving either 300 mg doxycycline (16.10 l) or standard tetracycline (14.80 l). Almost equal numbers of patients in each group required unscheduled intravenous acetate solution to correct dehydration during antibiotic treatment. Patients treated with doxycycline (low or high dose), however, had more prolonged excretion of bacteria.

CONCLUSIONS

A single 300 mg dose of doxycycline is as effective as the standard multiple dose tetracycline treatment for cholera in terms of stool output, duration of diarrhoea, vomiting, and requirement for oral rehydration solution.

Impact of acute diarrhoea on parasite loads

Parasites and diarrhoea are more frequent in poor populations. Parasite prevalence rates in post-diarrhoeal patients of the International Centre for Diarrhoeal Disease Research (ICDDRB) and in non-diarrhoeal populations of two Dhaka poor socioeconomic communities have been compared to explore if there is any effect of acute diarrhoea on parasite prevalence rates. Stool of a 4% systemic randomly selected sample of diarrhoeal patients and the whole population of two local poor communities have been examined. The results showed that the prevalence of parasites in a post-diarrhoeal population is significantly lower than in a non-diarrhoeal population. These reductions (E. hist. 10.2% vs. 2.03%, G. lamb. 9.7% vs. 3.5%, hookworm 37.4% vs. 4.7% and Ascaris lumbricoides 81% vs. 20.6%) may be attributed mainly to the flushing effect of diarrhoea.

Persistent diarrhoea: clinical efficacy and nutrient absorption with a rice based diet

Twenty six infant boys, aged 4 to 18 months, suffering from persistent diarrhoea and 25 age matched healthy controls without diarrhoea were given a diet based on rice powder, egg white, glucose, and soya oil. The clinical efficacy of the diet was studied and a 72 hour metabolic balance study was done. Twenty one patients recovered from diarrhoea within seven days. Median coefficients of absorption of nutrients in persistent diarrhoea patients were 68.0% (range 28.0 to 92.0) for total energy, 60.0% (range 21.0 to 97.0) for fat, 53.0% (range -122.0 to 82.0) for nitrogen, and 81.0% (range 23.0 to 97.0) for carbohydrates. The corresponding values among the control subjects were 90.0% (range 76.0 to 99.0), 95.0% (range 71.0 to 99.0), 70.0% (range 10.0 to 95.0), and 93.0% (range 85.0 to 98.0) respectively. Absorption of all macronutrients in the control subjects was on average significantly higher than in the patients. Nutrient absorption is substantially reduced in persistent diarrhoea and a rice based diet is clinically effective in most patients.

Oral rehydration formula containing alanine and glucose for treatment of diarrhoea: a controlled trial

OBJECTIVE

To determine whether adding L-alanine to the glucose based oral rehydration solution recommended by the World Health Organisation would improve its efficacy in treating acute diarrhoea.

DESIGN

Randomised double blind controlled trial of oral rehydration solution containing L-alanine and glucose.

SETTING

Inpatient service of a hospital treating diarrhoea.

PATIENTS

97 Male patients aged 6-59 years admitted to the hospital with acute and severe dehydration due to diarrhoea associated with Vibrio cholerae or enterotoxigenic Escherichia coli. Forty nine received the standard glucose based oral rehydration solution (control group) and 48 this solution with alanine added (study group).

INTERVENTIONS

All of the patients received rapid intravenous acetate solution for the initial four hours after admission, which fully corrected the signs of dehydration. They were then admitted to the study and randomised. Immediately after the intravenous treatment oral rehydration treatment was started. All of the patients received oral tetracycline for 48 hours, starting 24 hours after start of the study. If signs of dehydration reappeared during oral treatment patients were given rapid intravenous acetate solution until they were fully corrected and then continued to take the assigned oral rehydration solution.

END POINT

Passage of the last watery stool.

MEASUREMENTS AND MAIN RESULTS

The median stool output/kg body weight during the initial 24 hours of oral rehydration treatment and until diarrhoea stopped was reduced in the study group compared with the control group from 309 ml to 196 ml and from 393 ml to 236 ml respectively. Intake of oral rehydration solution and intravenous acetate solution was reduced from 455 ml to 308 ml and from 616 ml to 425 ml respectively. Two patients in the study group compared with 18 patients in the control group required unscheduled rapid intravenous acetate solution to correct signs of dehydration during oral rehydration treatment.

CONCLUSION

Oral rehydration solution containing L-alanine was considerably better than standard oral rehydration solution at reducing the severity of symptoms and the need for fluid of male patients with diarrhoea associated with V cholerae and enterotoxigenic E coli.

Persistent diarrhoea: a preliminary report on clinical features and dietary therapy in Bangladeshi children

Twenty-six infants and children aged 2-24 months suffering from diarrhoea for more than 2 weeks were studied in the ICDDRB's Dhaka Treatment Centre. They presented with watery diarrhoea and the majority had moderate dehydration. A stool pathogen was isolated in only one infant. Systemic infections co-existed in half of the subjects. Subjects between 4 and 12 months of age were moderately malnourished. The remainder were severely malnourished. A range of therapeutic diets were given according to the clinical progress of the subjects. Three children improved with a milk-based diet, two with a soya-based proprietary diet, eight with a rice-based diet, 12 with comminuted chicken, and one with yoghurt. Response to various diets appeared to be age related. Body weight of 21 subjects deteriorated before cessation of diarrhoea. Case fatality rate was 11 per cent due to septicaemia and bronchopneumonia. Most persistent diarrhoea patients without severe concurrent systemic infections were effectively treated using various locally prepared diets.

Risk factors for persistent diarrhoea

With a systematically sampled population of children aged under 5 attending this centre for diarrhoeal disease research during 1983-5 a retrospective analysis of persistent diarrhoea (defined as greater than 14 days' duration) was performed to identify the possible risk factors for this syndrome. Of the 4155 children included in the analysis, 410 (10%) gave a history of persistent diarrhoea. A comparison with children with acute diarrhoea matched for age showed that 11 factors were correlated with persistent diarrhoea, and strongly associated factors were stools with blood or mucus, or both, lower respiratory tract infection, malnutrition, vitamin A deficiency, and antibiotic use before presentation. The peak age was 2 years, and there was no sex difference. Deaths occurred more often in the group with persistent diarrhoea. Although Shigella spp, Campylobacter jejuni, and Giardia lamblia were frequently identified, their rates of isolation were not significantly higher among patients with persistent diarrhoea. No seasonal variation was observed in the rates of persistent diarrhoea. Although the introduction of family food to the diet was associated with higher rates, this factor was difficult to separate from the age dependent risks.

Rapid intravenous rehydration by means of a single polyelectrolyte solution with or without dextrose

We compared the efficacy and safety of a single polyelectrolyte solution, Dhaka solution (DS), containing 133 mmol/L sodium, 13 mmol/L potassium, 98 mmol/L chloride, and 48 mmol/L acetate with and without 139 mmol/L (25 gm/L) dextrose in the rapid (4 hours) rehydration of 67 patients with diarrhea and moderate or severe dehydration requiring parenteral fluid therapy. Of the 67 patient, 31 were randomly assigned to receive the dextrose-containing solution (DS + D) and 36 DS without dextrose. On admission to the hospital, the two groups of patients were similar with respect to enteric pathogens detected, proportion with hyponatremia, magnitude of dehydration as assessed by clinical criteria, serum protein or creatinine concentration, and plasma glucose levels. At the end of the 4-hour infusion, both groups of patients had similar decreases in serum creatinine and protein levels and similar volume of urine output, but patients receiving DS + D had a significantly higher plasma glucose level than patients receiving DS (7.8 mmol/L (140 mg/dl) vs 5.39 mmol/L (97 mg/dl), P less than 0.01). One patient in the DS group had hypoglycemia (plasma glucose 2.0 mmol/L (36 mg/dl) at 4 hours. No other complications were noted. Serum protein values 24 hours after admission were little changed from 4-hour values, suggesting that rehydration was complete at the end of 4 hours. We conclude that, in our patients, rehydration can be carried out safely and rapidly with the use of a single solution and that adding 139 mmol/L (25 gm/L) of dextrose to the solution can prevent hypoglycemia without producing an osmotic diuresis.

Effect of zinc supplementation on the dietary intake and weight gain of Bangladeshi children recovering from protein-energy malnutrition

Sixty severely malnourished children aged between 5 and 60 months were studied during nutritional rehabilitation. They all received a rice-based diet ad libitum plus vitamins and iron supplementation. Thirty children received zinc supplements (10 mg/kg/d for those weighing less than 6 kg and 50 mg daily for those over 6 kg) on a random basis. Zinc was started from the 15th hospital day when they were free of infection and continued for a period of 3 weeks. Both groups had a mean energy intake of 200 kcal/kg/d, but the majority of the supplemented children had a better rate of weight gain: 66 per cent of the supplemented compared with 33 per cent of the controls gained more than 10 g/kg body weight/d. Moreover, 76 per cent of the supplemented children compared with 23 per cent of the controls were over 90 per cent of Harvard median weight for height on discharge. It appears from this study that zinc supplementation promotes growth and enhances the rate of clinical recovery from severe PEM.

Interethnic variation in the metabolic inactivation of digoxin by the gut flora

Digoxin is metabolized to cardioinactive reduced metabolites (digoxin reduction products) in some patients by anaerobic bacteria present in the gut flora. We compared the tendencies of Americans and Bangladeshis to reduce digoxin by this pathway. Of 97 normal Americans in New York City, 34 (35.1%) were metabolizers in contrast to 14 of 100 Bangladeshis in Dhaka (p less than 0.002). Forty-three (35.8%) of 120 American patients in New York City receiving digoxin reduced the drug compared with 4 (13.8%) of 29 Bangladeshi patients in Dhaka (p less than 0.05). In Americans who emigrated to Dhaka or Bengali immigrants to New York City, the frequency of digoxin reduction product excretion was that of their country of origin. Fourteen Bengali immigrants who were nonmetabolizers when first studied in New York did not metabolize digoxin when restudied 4 yr later. In the Bangladeshis studied in Dhaka, income, education, and most strongly, urban residence during childhood correlated positively with digoxin inactivation. The findings are consistent with the hypothesis that the metabolic functions of the anaerobic gut flora may be determined by environmental factors operative early in life and tend to remain stable in adulthood. Interethnic variations in drug metabolism may be the consequence of differences in the intestinal microflora.

Cholera, rotavirus and ETEC diarrhoea: some clinico-epidemiological features

This paper analyses a few selected features from the history and clinical examination of 1258 patients with acute diarrhoea and a single laboratory diagnosis of either cholera, rotavirus, or enterotoxigenic (ETEC) Escherichia coli infection. Age distribution and seasonality in Bangladesh were also studied. The duration of illness before admission was not significantly different in the 3 groups. Cholera occurred especially in the spring and early winter. Most cholera patients were between 3 and 10 years of age. Over 37% of the patients developed severe dehydration. In about 90% of cholera cases, the stools were alkaline (pH greater than 7). ETEC infections were seen mostly in April-May and September-October. Infants were frequently affected but from age 25 onwards the age distribution closely followed that of cholera. Severe dehydration occurred in 8.3% of patients and was more frequent than in rotavirus cases. Stool pH was as frequently acidic as basic. Rotavirus cases were concentrated during the winter in patients under 2 years of age. They had marked vomiting, yet severe dehydration was almost absent. Cough was present in half of them. The stools were usually acidic. In spite of considerable overlap of signs and symptoms between the 3 aetiological groups, a presumptive diagnosis of cholera could be made in patients past infancy and early childhood who showed very severe dehydration. However, age-specific prevalence was strikingly different and seasonal variations considerable.

Hydrolysed wheat based oral rehydration solution for acute diarrhoea

A randomised three cell study was carried out in 78 children with acute diarrhoea to evaluate the relative efficacy of oral rehydration solution (ORS) made from partially hydrolysed wheat grain, cooked rice powder, or glucose. Twenty six patients with comparable age, body weight, duration of diarrhoea, and degree of dehydration were studied in each of the three groups. Initial rehydration was carried out by using intravenous Dhaka solution within one to two hours followed by administration of oral rehydration solution. The mean ORS intake during the first and second 24 hours of treatment in patients with cholera receiving wheat-ORS and rice-ORS was significantly less compared with those receiving glucose-ORS. The stool output during the same period in patients receiving wheat-ORS and rice-ORS was significantly less compared with those receiving glucose-ORS. Similar trends in both ORS intake and stool output were observed during the next 24 hours.

Persistent protein losing enteropathy in post measles diarrhoea

Faecal alpha 1 antitrypsin was measured in two groups of children with diarrhoea aged 6 months to 6 years during the acute and recovery stages of the illness. Group 1 comprised 19 children with a history of measles in the two weeks preceding admission to hospital. In this group there were six cases of Shigella species, six enterotoxigenic Escherichia coli, and five rotavirus, and two did not yield an aetiologic agent. Group 2 comprised 15 children with diarrhoea only. In this group there were five cases of Shigella species, five enterotoxigenic Escherichia coli, and five rotavirus. Children with rotavirus diarrhoea belonging to both groups showed a transient high faecal clearance of alpha 1 antitrypsin during the acute stage. Post measles cases of diarrhoea showed significantly higher faecal clearance of alpha 1 antitrypsin than group 2 subjects in both the acute and recovery stages. The faecal clearance of alpha 1 antitrypsin in both groups was significantly higher during the acute stage compared with the recovery stage. Highest faecal clearances of alpha 1 antitrypsin were observed in children with post measles shigellosis in the acute stage and they also had persistently raised concentrations, thus suggesting prolonged protein losing enteropathy.

Prolonged depression of serum zinc concentrations in children following post-measles diarrhoea

Serum zinc levels were measured in three groups of children aged 6 months to 6 years. In group I, there were 25 children with diarrhoea, who had a history of measles within the 2 weeks preceding the zinc level tests (post-measles diarrhoea); in group II there were 17 children who had diarrhoea only; and in group III there were 20 children who were apparently healthy and had neither diarrhoea nor measles (controls). Serum zinc concentrations of less than 5 mumol/l were observed in 5 out of 16 children in group I, but none of the children in group II had such low levels. The serum zinc level in group II rose significantly during the recovery stage compared to the acute stage (P less than 0.01). Children with post-measles diarrhoea showed a continued and prolonged depression of serum zinc levels.

Rapid technique for detection of pneumococcal pneumonia

Tracheal aspirates from patients with diarrhoea and pneumonia were tested for the presence of pneumococci by both quantitative culture and counter immunoelectrophoresis (CIE). Antigen was demonstrated by CIE in 33/48 of these confirmed cases of pneumonia. The technique is easy to use and gives rapid results.

A study in vitro of the sodium pump in fulminant hepatic failure

1. The mechanism underlying the raised leucocyte sodium content in fulminant hepatic failure was studied by measurement of sodium fluxes, (Na+ + K+)-dependent adenosine triphosphatase activity, and leucocyte ATP content. 2. The rate constant for sodium efflux in the leucocytes was significantly reduced, and attributable to reduced activity of the enzyme (Na+ + K+)-ATPase. Leucocyte ATP content was not significantly different from that of control cells. 3. Incubation of cells from patients in the sera of normal subjects resulted in a reversal of these changes. Inhibition of the leucocyte sodium efflux rate constants and (Na+ +K+)-ATPase of normal cells was achieved by incubation in sera from patients. 4. We suggest that the raised sodium content of leucocytes in fulminant hepatic failure is attributable to a defective sodium pumping mechanism, possibly due to a circulating toxin.

Changes in the electrolyte content of leucocytes at different clinical stages of cirrhosis

The intracellular sodium, potassium, and water content of isolated leucocytes was estimated in 47 patients with cirrhosis. The values for sodium showed a wide scatter. In patients without ascites the mean value was significantly increased but in those accumulating ascites it was normal, although often reduced in individual subjects. Reduced values were found in patients with hyponatraemia associated with end-stage cirrhosis and diuretic treatment. Changes in leucocyte water content closely followed those in sodium content. Leucocyte potassium content was normal except in patients accumulating ascites in whom it was significantly reduced, indicating whole body depletion, and this could be corrected by administration of spironolactone.

Potassium and magnesium depletion in patients with cirrhosis on maintenance diuretic regimens

Total body potassium (40K) and leucocyte potassium measurements were carried out on 19 patients with stable but decompensated cirrhosis maintained on diuretics for previous ascites. Of 13 patients receiving spironolactone alone none had a total body potassium below the expected lower limit of normal, whereas, of six receiving additional frusemide, two had low values. The results for leucocyte potassium were in agreement and simultaneous measurements of leucocyte magnesium showed a close correlation, those with intracellular potassium depletion also having magnesium depletion. One such patient was treated with magnesium supplements without effect on the potassium, although intracellular magnesium was improved. It is concluded that spironolactone alone is the treatment of choice in the maintenance management of such patients; that additional potassium would be unnecessary; and that additional frusemide should be avoided if possible.

Intracellular electrolyte abnormalities in fulminant hepatic failure

The sodium, potassium, and water content of peripheral blood leukocytes was determined in 30 patients with fulminant hepatic failure. Although values for potassium were reduced, statistically significant increases were found in sodium and water content. Serial studies showed that, with recovery of liver function, the leukocyte sodium content fell initially to below normal, with values subsequently returning to the normal range some weeks later. Leukocyte sodium content was inversely correlated to the plasma sodium concentration, suggesting that a shift of sodium into the intracellular compartment might contribute toward the hyponatremia that was found in many patients.