P-Fimbriated Clones Among Uropathogenic Escherichia Coli Strains (original) (raw)
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Isolation and characterisation of dog uropathogenic Escherichia coli strains and their fimbriae
Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology, 1988
A number of Escherichia coli strains have been isolated from dogs with urinary tract infections. These strains have been characterised with respect to their O, K, H, and fimbrial antigens, colicin production, antibiotic resistance, plasmid content and their ability to haemagglutinate erythrocytes from various species. Crossed immunoelectrophoresis of fimbrial extracts, as well as the reaction of partly purified fimbriae of a number of these strains with monoclonal antibodies revealed homology or a strong crossereaction with an F12 fimbrial subunit protein of human uropathogenic E. coli strains. Unlike human F12 fimbriae producing strains, the dog isolates did agglutinate dog erythrocytes in the presence of D-mannose but not human erythrocytes, indicating that the adhesin carried by these strains is different from the adhesin on fimbriae of human uropathogenic E. coli. Similar indications were obtained from experiments with latex beads coated with the receptor for P-fimbriae. These beads were agglutinated by Escherichia coli strains from human urinary tract infections, but not by the dog isolates described here. Preliminary adhesion experiments of human and dog Escherichia coli to human bladder epithelial and canine kidney epithelial cells also showed differences in adhesion depending on the origin of the strain tested.
Biological and genetic characteristics of uropathogenic Escherichia coli strains
Revista Do Instituto De Medicina Tropical De Sao Paulo, 2001
The aim of the present study was to determine biological characteristics such as expression of fimbriae, Congo red binding, production of hemolysin and aerobactin, adhesion to HeLa and uroepithelial cells and invasion of HeLa cells by Escherichia coli isolates obtained from patients showing clinical signs of urinary tract infection (UTI). Also, the presence of genes (apa, afa, spa) for fimbria expression and cytotoxic necrotizing factors (CNF1, CNF2) was assayed using specific primers in PCR. The data obtained were compared with the clonal relationships obtained by analysis of multilocus enzyme electrophoresis (MLEE), restriction fragment length polymorphism (RFLP) of the rDNA (ribotyping) and enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR). All isolates but one presented a combination of at least two of the characteristics studied, a fact suggesting the presence of pathogenicity islands (PAIs). Diffuse adherence type to HeLa cells was observed to occur in most of the strains, but adhesion to uroepithelial cells seems to be a more reliable test to verify pathogenicity. Although four strains seemed to be able to invade HeLa cells when assayed by light microscopy, electron microscopy studies demonstrated that these strains were not invasive. MLEE, RFLP and ERIC-PCR were able to group the isolates differently into main clusters that were not correlated with the presence of pathogenic traits.
Virulence factors of uropathogenic Escherichia coli
International Journal of Antimicrobial Agents, 2003
The aim of the study was to determine the occurrence of virulence genes expressing fimbriae, production of hemolysin, colicin and aerobactin among a hundred Escherichia coli isolates obtained from in-and outpatients of a tertiary-care teaching hospital, between July and August 2000, showing clinical and laboratory signs of urinary tract infection (UTI). The presence of genes (pap, afa, sfa) for fimbriae expression was assayed using specific primers in a polymerase chain reaction. Among the isolates studied, the prevalence of the virulence factors was 96.0%, 76.0%, 24.0%, for hemolysin, aerobactin and colicin, respectively; the prevalence of genes coding for fimbrial adhesive systems was 32.0%, 19.0% and 11.0% for pap, sfa and afa respectively. The strains isolated from the outpatients displayed a greater number of virulence factors compared to those from hospitalized subjects, emphasizing the difference between these two kinds of patients.
Virulence Characteristics of Escherichia coli in Nosocomial Urinary Tract Infection
Clinical Infectious Diseases, 1993
We examined 148 strains of Escherichia coli isolated from the urine from patients with nosocomial urinary tract infection (UTI). The prevalence of P fimbriation was only 11.5%. Of the strains, 17.6% expressed non-P M(R) adhesins (defined as strains expressing mannose-resistant but not P-specific hemagglutination); 33.1% produced hemolysin, and 15.2% expressed type 1C fimbriae. O6 was the most common group of O antigens (12.2%), closely followed by O75 (9.5%); both of these groups are relatively uncommon (4.5% and 1%, respectively) in fecal strains isolated from healthy adults. Of the strains with O6 and O75 antigens, 78.8% and 79% produced hemolysin, but of all other strains causing UTI, only 21% produced hemolysin. Of the strains with O6 antigens, 61% expressed non-P M(R) adhesins, but only 12% of all other strains causing UTI expressed non-P M(R) adhesins. There were no significant differences in the prevalence of virulence properties between strains isolated from patients with or without an underlying medical illness or between strains causing different clinical categories of UTI. We conclude that the prevalence of bacterial virulence factors is low among patients with nosocomial UTI.
Low Virulence of Escherichia coli Strains Causing Urinary Tract Infection in Renal Disease Patients
European Journal of Clinical Microbiology & Infectious Diseases, 2000
∑ Escherichia (E.) coli, which causes over 80% of uncomplicated urinary tract infections, may simultaneously express a number of virulence factors of relevance for urinary tract infections. Some of the recognized E. coli virulence factors are adherence to uroepithelial cells, certain O and K serotypes, hemolysin production, and aerobactin production. One of E. coli adhesins, P-fimbriae, are known as a major virulence factor in the development of acute uncomplicated pyelonephritis. The aim of this study was to determine the virulence properties of E. coli strains isolated from the urine of patients with chronic pyelonephritis, and to compare them to the properties of strains isolated from patients with acute pyelonephritis, acute cystitis, and asymptomatic bacteriuria. For each strain, O-serogroup, adhesin type, motility, production of hemolysin, and the amount of capsular polysaccharide were examined. The strains isolated from patients with acute pyelonephritis were found to mostly express all five or four virulence markers tested, while the less virulent strains were detected in the group of patients with chronic pyelonephritis, where most strains expressed up to three virulence markers. The lowest virulence was observed among the strains isolated in the group of patients with asymptomatic bacteriuria. Expression of P-fimbriae and production of hemolysin were found to be the most important virulence factors with the highest power for discrimination between chronic and acute upper urinary tract infection (p<0.01).
A Study of Escherichia Coli Isolated from Chronic Urinary Infection
Journal of Medical Microbiology, 1969
ESCHERICHIA C O L I is a comrnon cause of both acute and chronic urinary infection. Most studies of serological types of E. coli responsible for urinary tract infection have been concerned with the acute disease and particularly with urinary tract infection in pregnancy (Kunin, 1963; Vosti et al., 1964); much less information is available about serotypes found in chronic disease.
International Journal of Advances in Medicine, 2014
The Urinary Tract Infections (UTIs) are one of the most prevalent bacterial infections. 1 E. coli accounts for 50%-90% of all the uncomplicated urinary tract infections. 2 These E. coli are primarily derived from the faecal flora, which can colonize the periurethral area, overcome the local host defences and enter and multiply within the urinary tract. These E. coli strains are designed as Uropathogenic E. Coli (UPEC) which possess distinctive traits that confer an enhanced extraintestinal virulence potential. 4-6 UTI is predominantly a disease of the females, because of the anatomy of the female urethra. The incidence of bacteriuria increases during pregnancy, due to the anatomical and the hormonal changes. In most of the hospitalized patients, nearly all the UTIs are preceded by the instrumentation of the urinary tract, mainly urinary catheterization and it is a frequent cause of significant morbidity, sepsis and death. 4 Most of the strains of E. coli which cause UTIs belong to a restricted range of serotypes which are different from the distribution in the faecal isolates. However, the serotypes alone cannot explain the uropathogenicity of E.
2014
The gut constitutes an important reservoir of bacteria causing extra intestinal infections such as urinary tract infection (UTI). According to the fecal-vaginal-urethral hypothesis, E. coli strains causing UTI usually derive immediately from the host's own fecal and perineal flora. We assessed multiplex PCR assays to detect type 1 fimbriae among E.coli subtypes in children with symptom of urinary tract or gastrointestinal infection. Material and Methods: We used multiplex PCR assays that detect enteropathogenic E. coli (EPEC) isolates, enteroaggregative E. coli (EAEC) isolates, enterotoxigenic E. coli (ETEC) isolates, enteroinvasive E. coli (EIEC) isolates, and enterohemorrhagic E. coli (EHEC) isolates. Also the isolates were examined for type 1 fimbriae. The targets selected for each group were eae for EPEC isolates, aggR for EAEC isolates, and the genes encoding heatlabile and heat-stable toxins for ETEC isolates, stx1 and stx2 for EHEC isolates, invE for EIEC isolates and fimH for detection of type 1 fimbriae. Results: In this study more than 80% of E. coli isolates from the Urine and rectal swab samples of childrens have the genes for type 1 fimbriae. Among 101 rectal swab specimens tested, 48.5% had fimH gene, 2% were EHEC, 3% ETEC and 4% EAEC; we also detected mixed infections, 1% with ETEC and EHEC, 4% EHEC with fimH gene, 11.9% ETEC with fimH gene, 5.9% EAEC with fimH gene, 6.9% EHEC with ETEC with fimH gene, 1% EHEC and EAEC with fimH gene, 2% ETEC and EAEC with fimH gene. EIEC and EPEC were not found among the isolates tested. From 101 urine specimens tested 56.4% had fimH gene, 2% were EHEC, 2% ETEC, 3% EAEC; we also detected mixed infections, 1% with EAEC and EHEC, 7.9% EHEC with fimH gene, 9.9% ETEC with fimH gene and 3% EAEC with fimH gene. EIEC and EPEC were not found among the isolates tested. Discussion: As our understanding of the molecular aspects and detection of more than 80% fimH gene in E. coli strains it has been possible to design vaccines that target adaptive responses against specific bacterial proteins such as FimH tip adhesin of type 1 fimbriae. The antibodies produced can interfere with the function of essential bacterial virulence factors and can prevent the bacteria from adhering to and invading the host. [Hosein Heydari, Mohmmad Reza Shokrollahi, Zahra Movahedi. Frequency of type 1 fimbriae among E.coli subtypes isolated from patients with urinary and gastrointestinal tract infection.
The Use of Biochemical Markers, Serotype and Fimbriation in the Detection of Escherichia coli Clones
Microbiology, 1987
Biochemical reactions, 0 and K serotypes and presence of P-fimbriae were analysed in 116 Escherichia coli strains isolated in blood cultures from patients with bacteraemia and in 99 faecal strains isolated from healthy individuals. By using biochemical typing, the strains could be grouped into six main clusters with similarity index <0.8 (Gower, 1971) and altogether 16 subclusters with similarity index 0.82-0-89. The most discriminating tests between the clusters were fermentation of D-tagatose, saccharose, salicin and sorbose. No single biochemical property could differentiate bacteraemic isolates from faecal strains, although strains isolated from blood were significantly more often found in certain subclusters, whereas other subclusters contained mainly control strains. Bacteraemic strains possessed P-fimbriae more often, especially strains isolated from patients with E. coli in the urine concomitantly with bacteraemia. Equally, no single reaction could separate P-fimbriated from non-P-fimbriated strains. D-Tagatose was fermented more often by the P-fimbriated strains; on the other hand, melibiose and lactose fermentation tests were less often positive. Certain 0 serotypes (01, 0 4 , 06, 0 7 , 018 and 025) were more common among bacteraemic isolates than controls. K serotypes such as K 1, K5 and K52 were also more frequent among blood isolates. We conclude that a combination of biochemical tests, fimbriation and serotyping might be used to identify potentially pathogenic clusters of E. coli.
Journal of Medical Microbiology, 1994
, One hundred and sixty-eight strains of Escherichia coli were isolated from cases of pyelonephritis (24) and lower urinary tract infections (UTI) (144) from hospitalised and outpatient children up to 2 years old. These strains were investigated for the expression of P fimbriae (PF), mannose-resistant and mannose-sensitive haemagglutination, cell-surface hydrophobicity, serum resistance and the production of a-haemolysin (AH), colicins and aerobactin. PF, AH, aerobactin production and serum resistance were significantly more frequent amongst strains expressing mannose-resistant haemagglutination. PF and AH production was significantly more frequent in pyelonephritogenic strains than in lower UTI strains. Serotypes 0 6 and 0 1 12 were isolated most frequently and plasmids were found in the majority of strains tested. Materials and methods Bacterial strains One hundred and sixty-eight strains of E. coli were isolated from the urine of patients with either pyelonephritis (24) or lower UTI (144). Most were isolated from hospitalised infants < 2 years old. From each primary isolation plate of MacConkey agar, only one colony was picked for further investigation. Identifi-~~~