Asymptomatic bacteriuria Escherichia coli strains: adhesins, growth and competition.

Urinary tract infections (UTIs) affect millions of people each year. Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU) in humans. Persons affected by ABU may carry a particular E. coli strain for extended periods of time without any symptoms. In contrast to uropathogenic E. coli (UPEC) that cause symptomatic UTI, very little is known about the mechanisms by which these strains colonize the urinary tract. Here, we have investigated the growth characteristics in human urine as well as adhesin repertoire of nine ABU strains; the ability of ABU strains to compete against the UPEC strain CFT073 was also studied. The different ABU strains displayed a wide variety of the measured characteristics. Half of the ABU strains displayed functional type 1 fimbriae while only one expressed functional P fimbriae. A good correlation between the growth rate of a particular strain and the survival of the strain in competition against CFT073 was observed. Our results support the notion that for strains with reduced capacity to express fimbriae, the ability to grow fast in human urine becomes crucial for colonization of the urinary tract.

Roos V ，Nielsen EM ，Klemm P 《FEMS MICROBIOLOGY LETTERS》

Biofilm formation by asymptomatic and virulent urinary tract infectious Escherichia coli strains.

Hancock V ，Ferrières L ，Klemm P 《FEMS MICROBIOLOGY LETTERS》

Virulence properties of asymptomatic bacteriuria Escherichia coli.

Mabbett AN ，Ulett GC ，Watts RE ，Tree JJ ，Totsika M ，Ong CL ，Wood JM ，Monaghan W ，Looke DF ，Nimmo GR ，Svanborg C ，Schembri MA ... -  《-》

[Occurrence of p-fimbriae in enteropathogenic E coli (EPEC) and in E. coli strains isolated from patients with urinary tract infections].

The aim of this study was to gain knowledge of prevalence of P+ clones among EPEC strains isolated from children with diarrhoea and E. coli strains isolated from urine. Three hundred eighty four E. coli strains isolated from children with diarrhoea were tested. They belonged to 11 serotypes (018, 025, 026, 044, 055, 0111, 0114, 0119, 0124, 0125, and 0128). Nine hundred thirty colonies of E. coli from Mac Conkey's agar plated quantitatively with urine samples of 178 individuals suffering from urinary tract infections were also tested. All strains were assayed by mannose-resistant active haemagglutination test (MRHA) and by slide agglutination using self prepared latex reagent for detection of P fimbriae. Out of 384 E. coli strains tested 122 (31.8%) showed presence of adhesins detected by mannose-resistant active haemagglutination test (MRHA) and in 90 (23.3%) out of all tested strains the presence of P fimbriae was found. The highest percentage of P fimbriae prevalence was found in E. coli belonging to the following serotypes: 018 (in 68.9% strains), 025 (in 29.2% strains), and 0125 (in 25.0% strains). This type of fimbriae was also detected in serotypes 026 (9.1%), 044 (8.7%), 055 (5.6%), and 0119 (in 2 strains out of 5 isolated). Out of 933 colonies of E. coli, isolated from 178 urine samples, 434 (46.5%) colonies gave positive results in MRHA test, including 133 positive in latex test for P fimbriae. These studies showed that for MRHA adhesins, including P fimbriae, a parallel examination of higher number of E. coli was necessary.(ABSTRACT TRUNCATED AT 250 WORDS)

Kałuzewski S ，Jagielski M ，Szych J ，Andziak J ... -  《-》

[Relation between P-fimbriae and resistance to amoxicillin, carbenicillin and tetracycline in uropathogenic strains of Escherichia coli].

Vranes J ，Schönwald S ，Zagar Z 《-》