Distribution of genes encoding iron uptake systems among enteroaggregative Escherichia coli strains isolated from adults with irritable bowel syndrome.

The distribution of genes encoding different iron acquisition systems in enteroaggregative Escherichia coli (EAEC) from adults with irritable bowel syndrome and from healthy controls was examined using a PCR assay. As many as 95.5% of EAEC carried the chuA gene coding for a haem receptor, and the majority of these strains also had yersiniobactin-encoding genes. Apart from yersiniobactin, enterobactin was the siderophore most frequently associated with EAEC among those strains examined. Genes encoding aerobactin and salmochelin siderophores were less frequent in the group of EAEC.

Association of enteroaggregative Escherichia coli with irritable bowel syndrome.

Increased numbers of faecal Enterobacteriaceae are observed among patients with irritable bowel syndrome. Escherichia coli strains are present in the lower intestine of humans, and may include several potentially pathogenic adhesive pathotypes. The aim of this study was to determine whether there were differences between the adhesive pathotypes of E. coli strains recovered from stool specimens of patients with irritable bowel syndrome and those recovered from healthy controls. The ability of E. coli isolates to adhere to cultured epithelial cells was assessed in an in-vitro adherence assay with HEp-2 cells. Enteroaggregative E. coli (EAEC) strains were isolated significantly more frequently (p <0.00001) from patients with irritable bowel syndrome (81.8%) than from healthy controls (32.3%). However, despite this association, the precise role of the EAEC pathotype in irritable bowel syndrome remains to be determined.

Enteroaggregative and cell-detaching Escherichia coli strains among Polish children with and without diarrhea.

To determine the association of enteroaggregative (EAEC) and cell-detaching (CDEC) Escherichia coli with diarrhea of unknown origin among children from Wroclaw (Poland), E. coli strains isolated from stool specimens of children with diarrhea were examined for mannose-resistant adherence to HEp-2 cells. EAEC were isolated from 10 of 39 (26%) children examined with diarrhea and 4 of 20 (20%) age-matched controls. CDEC were present in 14 (36%) cases of diarrhea and 7 (35%) healthy subjects. Cell-detaching activity was distinctly associated with hemolysin production. Among hemolytic CDEC strains cytotoxic necrotizing factor 1 (CNF1) synthesis prevailed among isolates obtained from cases of diarrhea (57%) in comparison with isolates obtained from healthy controls (14.3%). Although neither EAEC nor CDEC E. coli strains were associated with diarrhea of children in this setting, there were differences among EAEC and CDEC strains isolated from children with and without diarrhea.

[Adherence patterns of Escherichia coli strains isolated from children with diarrhea]. / Typy adhezji szczepów Escherichia coli izolowanych z przypadków biegunek.

Among enteropathogenic E. coli strains (EPEC) there are different patterns of adherence to the culture cells in vitro assay: localized, localized-like and diffuse. The adherence pattern is dependent on the ability of E. coli strains to cause of diarrhea. The strains locally adhering possess a 60 MDa plasmid--E. coli adherence factor (EAF), and produce characteristic histopathologic intestinal lesions linked with the presence of chromosomal eae gene. The pathogenicity of diffusely adherent as well as cells detaching E. coli (CDEC) remains controversial. The aim of the study was to identify the adherence patterns of E. coli strains isolated from children with diarrhea and to compare that patterns with the serotypes and the presence of EAF and/or pO157 plasmids, fimbriae and eae, stx1, and stx2 specific sequences. Nine out of examined E. coli strains showed the localized pattern of adherence. About half (46.8%) of strains were diffusely adherent and six isolates were cells detaching E. coli (CDEC). A total of 22 (23%) examined strains showed the presence of specific for verocytotoxins sequences. The results showed that many strains recognized on the ground of agglutination with specific EPEC antisera as unpathogenic could be an etiologic agents of diarrhea which are able to produce histopathologic lesions in the intestinal epithelium. In turn, many strains classified as EPEC could be unpathogenic on the basis of diffuse pattern of adherence.

[Characteristic of verotoxigenic strains of Escherichia coli]. / Charakterystyka verotoksycznych szczepów Escherichia coli.

The aim of the study was the isolation from faecal samples of patients with diarrhoea of verotoxigenic strains of E. coli (VTEC) on the basis of characteristic biochemical properties and production of enterohaemolysin and comparison of isolated verotoxigenic strains with reference strains of VTEC. For isolation of VTEC from 257 stool samples derived from patients with diarrhoea were used selective medium sorbiol--Mac Conkey agar (SMAC) and media supplemented with unwashed and washed in PBS sheep erythrocytes for detection of haemolysins of E. coli. In all haemolytic and sorbitolo-positive or -negative strains isolated from 93 stool samples were examined the activity of beta-glucuronidase using MUG (4-methylumbelliferyl-beta-D-glukuronid) as a substrate for that enzyme. All isolated haemolytic strains as well as reference VTEC were examined on Vero cell line. Verotoxigenic strains from examined samples were investigated by agglutination assay with antiserum to E. coli O157 and then with antisera to eneropathogenic E. coli (EPEC). After that they were examined with ID GN and ATB GN tests. In 93 (36.2%) examined samples there were haemolytic strains of E. coli which fermented or not sorbitol and were MUG-positive or negative. Only in 2 (0.2%) stool samples there were verotoxigenic strains of E. coli which were sorbiol-positive and MG-positive. Both strains belonged to O26 serotype and were derived from samples of two children with diarrhoea. Isolated verotoxigenic strains of E. coli O26 were susceptible on all tested antibiotics.

[The presence of antibodies to Borrelia burgdorferi associated with immunologic complexes in sera of foresters]. / Obecnosc przeciwcial dla Borrelia burgdorferi zwiazanych w kompleksy immunologiczne w surowicach lesników.

Binding of antibodies specific to Borrelia burgdorferi in circulating immune complexes can lead to false negative results in serological tests. The aim of our study was to determine the presence of IgM antibodies to Borrelia burgdorferi bound in immune complexes in 52 sera of foresters the National Park in Karkonosze. Free and bound in immune complexes IgM antibodies present in 6 (11.5%) examined sera. In 24 (46.2%) seronegative sera after dissociation of immune complexes IgM antibodies to spirochaeta were found. The rest of the examined seronegative sera we failed to find IgM antibodies to Borrelia burgdorferi. The diagnostic assay, such as antibody analysis of immune components is useful in establishing of the diagnosis of borreliosis in seronegative cases and monitoring of disease activity. That method should be introduced for routine diagnosis of Lyme disease.

[Serologic diagnosis of infections caused by Borrelia burgdorferi]. / Serologiczna diagnostyka zakazen wywolanych przez Borrelia burgdorferi.

This investigation was aimed at selection of optimal serological test for diagnosis of borreliosis occurring at our territory. In our investigations, and indirect immunofluorescence test (IF) was used in which antigen consisted of an American strain of Borrelia burgdorferi B31 and immunoenzymatic test (IE) with an antigen prepared from an European strain. Hundred sixty eight sera were tested, including 138 sera received from patients with suspection of borreliosis or directed for testing because of suspected tick bite. Thirty sera from healthy blood donors served as a control. In 30 out of 138 patients with suspected borreliosis presence of specific antibodies in IF or IE test was detected. In control group positive results were obtained in 4 persons. From our study comparing two tests occurs that more suitable for serodiagnosis of borreliosis on our territory is determination employing as an antigen the European strain of Borrelia burgdorferi.