Identification of diarrheagenic Escherichia coli isolated from infants and children in Dar es Salaam, Tanzania

<p>Abstract</p> <p>Background</p> <p>Relatively few studies have been done in Tanzania to detect and classify diarrheagenic <it>Escherichia coli </it>(DEC) strains among children with diarrhea. This study aimed at investigating DEC among children in Dar es Salaam aged less than five years hospitalized due to acute/persistent diarrhea.</p> <p>Methods</p> <p>DEC were isolated from stool samples collected from two hundred and eighty children with acute/persistent diarrhea at Muhimbili National Hospital and Ilala and Mwananyamala Municipal Hospitals in Dar es Salaam. A multiplex PCR system method was used to detect a species specific gene for <it>E.coli </it>and ten different virulence genes for detection of five pathogroups of DEC namely enteroaggregative- (EAEC), enteropathogenic- (EPEC), enterotoxigenic- (ETEC), enteroinvasive- (EIEC) and enterohemorghagic- <it>Escherichia coli </it>(EHEC).</p> <p>Results</p> <p>Sixty-four patients (22.9%) harbored DEC. Forty-one of them (14.6%) were categorized as EAEC. Most of the EAEC (82.9%) were classified as typical EAEC possessing the <it>aggR </it>gene, and 92.6% carried the <it>aat </it>gene. Isolates from thirteen patients were EPEC (4.6%) and most of these (92.3%) were typical EPEC with both <it>eae </it>and <it>bfpA </it>genes. Ten isolates were identified as ETEC (3.6%) with only the heat stable toxin; either <it>st1a </it>or <it>st1b </it>but not both. Age wise, EAEC and EPEC were significantly more prevalent among the age group 0–6 months (p < 0.05). Genes for EHEC (<it>stx</it>₁and <it>stx</it>₂) and EIEC <it>(ial</it>) were not detected in this study group.</p> <p>Conclusion</p> <p>The results show a high proportion of DEC among Tanzanian children with diarrhea, with typical EAEC and typical EPEC predominating. The use of primers for both variants of ST1 (st1a and st1b) increased the sensitivity for detection of ETEC strains.</p

Escherichia coli infections and malnutrition

Universidade Federal de São Paulo, Escola Paulista Med, Div Paediat Gastroenterol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Div Paediat Gastroenterol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol, São Paulo, BrazilWeb of Scienc

Methylation Pattern of THBS1, GATA-4, and HIC1 in Pediatric and Adult Patients Infected with Helicobacter pylori

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Background Helicobacter pylori infection is usually acquired in childhood and persists into adulthood if untreated. The bacterium induces a chronic inflammatory response, which is associated with epigenetic alterations in oncogenes, tumor-suppressor genes, cell-cycle regulators, and cell-adhesion molecules. Aim The aim of this study was to analyze the effect of H. pylori infection on the methylation status of Thrombospondin-1 (THBS1), Hypermethylated in cancer 1 (HIC1) and Gata binding protein-4 (GATA-4) in gastric biopsy samples from children and adults infected or uninfected with the bacterium and in samples obtained from gastric cancer patients. Methods The methylation pattern was analyzed with methylation-specific PCR. Results Our results showed that H. pylori infection was associated with methylation of the promoter regions of the THBS1 and GATA-4 genes in pediatric and adult samples (p < 0.01). HIC1 showed the lowest level of methylation, which was not an early event during gastric carcinogenesis. Conclusions The results from this study indicate that methylation of THBS1 and GATA-4 occurs in the early stages of chronic gastritis and gastric cancer in association with H. pylori infection; however, in gastric cancer samples, other mechanisms cooperate with the down-regulation of these genes. Methylation of HIC1 may not be the principal mechanism implicated in its down-regulation in gastric cancer samples.581028502857Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2008/02678-6

DETECTION of IMMUNOGLOBULIN (IGG and IGA) ANTI-OUTER-MEMBRANE PROTEINS of ENTEROPATHOGENIC ESCHERICHIA-COLI (EPEC) in SALIVA, COLOSTRUM, BREAST-MILK, SERUM, CORD-BLOOD and AMNIOTIC-FLUID - STUDY of INHIBITION of LOCALIZED ADHERENCE of EPEC TO HELA-CELLS

ESCOLA PAULISTA MED,DEPT PEDIAT,DIV RHEUMATOL ALLERGY & CLIN IMMUNOL,BR-04025002 São Paulo,BRAZILESCOLA PAULISTA MED,DEPT MICROBIOL IMMUNOL & PARASITOL,São Paulo,BRAZILESCOLA PAULISTA MED,DEPT PEDIAT,DIV RHEUMATOL ALLERGY & CLIN IMMUNOL,BR-04025002 São Paulo,BRAZILESCOLA PAULISTA MED,DEPT MICROBIOL IMMUNOL & PARASITOL,São Paulo,BRAZILWeb of Scienc

PLASMID CODING FOR DRUG-RESISTANCE AND INVASION OF EPITHELIAL-CELLS IN ENTEROPATHOGENIC ESCHERICHIA-COLI-0111-H-

Enteropathogenic Escherichia coli (EPEC) can adhere to, invade and multiply in human epithelial cells. To define the elements required for bacterial invasion, we isolated from an 0111:H- EPEC a 6.6 kb plasmid that is capable of conferring to an avirulent, non-adherent E. coli K12 strain (DK1) the capacity to invade epithelial cells. With this system a dissociation was possible between bacterial invasion and adherence to epithelial cells. Bacteria containing this plasmid synthesise a protein of 32 kDa (pi 4.93) which seemed to be required for cell invasion. The results provide a new basis for strategies to prevent EPEC infections.18638739