Detection of PCR products of the ipaH gene from Shigella and enteroinvasive Escherichia coli by enzyme linked immunosorbent assay.

PCR techniques applied to diarrheal stools reliably diagnose Shigella and enteroinvasive Escherichia coli (EIEC) infections. Identification of PCR products using agarose gel electrophoresis (AGE) and hybridization with DNA probes has several shortcomings. Automated methods of identifying PCR products that process larger numbers of specimens can facilitate epidemiologic studies and standardize results. In this study, we used ELISA following PCR to detect ipaH gene sequences of Shigella and EIEC from 89 diarrheal stools. Results of ELISA were compared with AGE with and without DNA probe, and with culture. Two specimen preparation methods were compared as well: boiling/centrifugation, and purification with silicon dioxide (SiO(2)). Both PCR product-detection methods identified significantly more infections than did culture. PCR-ELISA detected significantly more infections than PCR-AGE when processed using SiO2 (P = 0.014). PCR-ELISA allows screening of larger numbers of specimens, automates test results, and avoids use of mutagenic reagents. PCR-ELISA is faster than PCR-AGE when testing large numbers of specimens, although not when testing small numbers of specimens.

Multidrug-resistant enteroaggregative Escherichia coli associated with persistent diarrhea in Kenyan children.

To study the association of multidrug-resistant enteroaggregative Escherichia coli with persistent diarrhea in Kenyan children, stool specimens were obtained from 862 outpatients under 5 years of age from July 1991 to June 1993. E. coli O44 was identified as the sole bacterial pathogen in four patients experiencing at least 14 days of fever, vomiting, and diarrhea. Disk diffusion testing showed E. coli O44 resistance to tetracycline, ampicillin, erythromycin, trimethoprim-sulphamethoxazole, and amoxicillin/clavulanate and sensitivity to chloramphenicol, nalidixic acid, azithromycin, and cefuroxime. Further studies are needed to clarify the epidemiology, clinical spectrum, and pathogenesis of enteroaggregative E. coli infection.

Epidemiological study on infectious diarrheal diseases in children in a coastal rural area of Kenya.

Diarrheal diseases are major causes of morbidity and mortality among children in developing countries. We have analyzed the causative agents of diarrhea in children under five years of age who resided in rural environments but attended a hospital in Malindi, a coastal town in Kenya. Bacterial diarrhea was found in 239 (27.7%) of 862 patients with diarrhea. Diarrheagenic Escherichia coli, including enteropathogenic, enterotoxigenic, and enterohaemorrhagic strains, was isolated from 119 (13.8%) patients, followed by Salmonella spp. (63 cases, 7.3%) and Shigella spp. (56 cases, 6.5%). Intestinal parasites were found in 109 (12.6%) of the patients. Entamoeba histolytica and Giardia lamblia were found in 67 (7.8%) and 42 (4.9%) of the cases, respectively. Rotavirus was found in 69 (16.1%) of 428 cases, a part of the 862 cases. Significant differences in age distribution were seen in diarrheal cases due to Campylobacter spp., G. lamblia, and rotavirus. No significant seasonal incidence of specific pathogens was found, but the number of diarrheal patients was significantly correlated to rainfall. Drinking water was contaminated with bacteria at concentrations ranging from 10(3) to 10(6) CFU/ml in 98% of the households and by coliform bacteria at concentrations of 10(2) to 10(5) CFU/ml in 72% of the households. These results suggest that the main routes of infection may be contaminated drinking water and fecal-oral transmission of enteric pathogens. Consequently, we propose that the enhancement of hygienic practice through health education is a feasible control measure of diarrhea in the study area.

Plasmid profiles of E. coli, Salmonella and shigella organisms isolated in Kenya.

A number of serotypable E. coli, Salmonella and Shigella strains isolated from three districts in Kenya were investigated for carriage of plasmids. This was done through extraction of plasmids and separating them by electrophoresis on agarose. Most of the strains investigated showed presence of plasmids. The E. coli isolates had plasmids ranging in number from 1 to 5, the most common number was 2. The plasmid sizes ranged from 80 to 30 megadalton, the commonest of the heavy plasmids were 70 megadalton. The Shigella isolates had plasmids ranging in number from 1 to 3, the most common number was 1. The plasmid sizes ranged from 80 to 3.5 megadalton, the commonest of the heavy plasmids were 70 megadalton. Various plasmid-sizes have been published as being responsible for pathogenicity.

Aetiogical agents of diarrhea in children living in a malaria epidemic area of Kenya

One hundred and four fecal specimen of children under five years reporting to Malindi Hospital were analysed for diarrhoegenic agents. These included bacterial; viral and parasitic agents which may cause diarrhoea. Conventional methods were employed in this study. The children were also examined for malaria parasites. consistency of the stool samples was loose 49; watery 26; formed 16; mucoid 9 and 3 of the specimen had traces of blood. 29 of the children were positive for malaria. Detection of diarrhoegenic agents was as follows;- 1. Bacteria 34; the highest of these being pathogenic Escherichia coli 39; Salmonella 28; Shigella 28 and Vibrio parahaemolyticus 3; 2. Rotaviruses 28; 3. Parasites 10 which included Ascaris lumbricoides 44; Trichuris trichura 33; Giardia lamblia 22 and Entamoeba coli 11. Mixed infections were observed in 7 of the subjects. Aetiological agents of diarrhoea could not be detected in 30 of the specimen

Minimum inhibitory concentration of antibiotics against bacteria associated with childhood diarrhoea in children attending a district hospital in Kenya

A study to determine the in vitro activity of antibiotics to bacterial pathogens isolated from diarrhoea stools of 125 patients reporting to the Paediatric Filter Clinic at Malindi District Hospital with acute diarrhoea was done. The ages of the patients ranged from one to five years. Samples of diarrhoea stools were collected before drug administration. 33 strains of Enterobacteriacea comprising 12 strains of pathogenic Escherichia coli; 13 strains of Salmonella SPP and 8 strains of Shigella SPP were isolated and minimum inhibitory concentration of five antibiotics determined. 5 pure antibiotic powders; namely; ampicillin; tetracycline; kanamycin; trimethoprim-sulfamethoxazole and nalidixic acid were tested using the agar dilution method (Muellerinton agar). The minimum inhibitory concentration (MIC) of the 5 antibiotics used ranged between 8#gml-1 and 128#gml-1 excep for t trimethoprin-sulfamethoxazole which had a MIC range of 0.25#gml-1 to 16#gml-1. Hyper resistance of the isolates was observed for ampicillin; tetracycline; kanamycin and nalidixic acid. The results of this work suggest that there is circulation of resistant strains of bacteria causing diarrhoea within the community around Malindi

Physicochemical characteristics and flora of diarrhoeal and recovery faeces in children with acute gastro-enteritis in Kenya.

Physiochemical characteristics and flora of diarrhoeal and recovery faeces were investigated in 14 Kenyan children with acute gastro-enteritis. Causative micro-organisms were Shigella, Campylobacter, enterotoxigenic Escherichia coli, rotavirus and unknown in 6, 2, 1, 2 and 3 patients, respectively. The mean values of the pH of the diarrhoeal specimens were significantly higher than those of the recovery specimens. Large amounts of acetic acid and many other kinds of fatty acids were detected in the recovery specimens, but small amounts and few kinds of fatty acids were detected in the diarrhoeal specimens. Bacterial counts of anaerobic organisms, such as Bacteroides, Bifidobacterium, Lactobacillus and Eubacterium, were lower in the diarrhoeal specimens than in the recovery ones. The normal anaerobic intestinal flora is remarkably disturbed in patients with acute gastro-enteritis. This may result in changes in fatty acid contents and in the pH of diarrhoeal faeces.