A comparative study of the mannose-resistant and mannose-sensitive haemagglutinins of Escherichia coli isolated from urinary tract infections

Abstract

The distribution of mannose-resistant (MRHA) and mannose-sensitive (MSHA) fimbrial haemagglutinins was examined in 482 strains of Escherichia coli isolated from 390 adult women and 45 pregnant mothers with a variety of urinary tract infections (UTI), and from 47 healthy controls. The proportion of MRHA strains was significantly higher in patients with symptomatic UTI (75%) than in women with non-significant bacteriuria (30%, p less than 0.001), pregnant women with asymptomatic UTI (34%, p less than 0.0001) and healthy controls (0%). The proportion of MSHA strains was significantly lower in patients with symptomatic UTI (22%) than in women with non-significant bacteriuria (46%, p less than 0.001) and pregnant women with asymptomatic UTI (52%, p less than 0.01). Only 17% of the strains from healthy controls had MSHA activity. In pregnant women with UTI, whether this was symptomatic or asymptomatic, there was a significant association between infection with MRHA strains of E. coli and a past history of UTI. Thus, in a pregnant woman with an infection and a past history of UTI there is a seven-fold greater chance that this infection is due to an MRHA-bearing organism than in pregnant women without such a history. There was also a significant association between MRHA organisms and symptomatic infection. The risk of symptomatic patients having an infection with an MRHA strain is six times greater than that for a patient with a covert infection.

Virulence factors in Escherichia coli urinary tract infection

“…However, using more-sensitive methods and morecareful patient selection, others have found evidence of fimbriation and adherence in bacteria in a substantial proportion of urine specimens from infected patients (313,390,427) (181,198,338,469,470,472,509,512,518,527). Hemagglutination testing yields similar results, with the highest proportion of MRHA strains among pyelonephritis patient isolates (50 to 81%) and progressively lower proportions among cystitis patient isolates (17 to 52%), ABU patient isolates (11 to 19%), and fecal isolates (2 to 29%) (48, 49,102,139,162,181,315,316,354,399,423,509,566). This evidence indicates that mannose-resistant uroepithelial-cell adherence and MRHA are characteristic of strains with an increased ability to cause UTI (especially the more clinically severe forms) and suggests that these properties may contribute directly to urovirulence.…”

Pathogenic factors in recurrent urinary tract infections and renal scar formation in children

“…Both kinds of pili have been demonstrated on UTI-causing E. coli strains [34,52,54]. Pili I-expressing bacteria attach to mannose-containing uromucoid, mainly Tamm-Horsefall protein [33].…”

“…Furthermore, MS pill cause agglutination of guinea-pig erythrocytes whereas MR pili agglutinate human red blood cells [34]. It has been shown that MR pili recognize P blood group antigens within the human erythrocyte membrane [52].…”

“…Further investigations showed that two kinds of bacterial pili were mainly responsible for adherence to preformed receptors on the host cell surface [25,34,52,54]. The fimbriae were defined by their specific receptor structures (Table 3): pill I that bind to mannose residues within an as yet unidentified receptor on the cell surface [1], and pili II that specifically recognize galactose-al-4[3-galactosedisaccharides in globoseries glycolipids (triosylceramide and tetraosylceramide) on the epithelial cell membrane [25,34,52].…”

“…The probable role of MR pili as virulence factors in UTI has often been assessed: A significant number of urinary isolates obtained from patients with pyelonephritis belong to pili II expressing E. coli strains (Table 4), whereas isolates obtained from patients with acute cystitis and with ABU or those from the faeces of healthy children are mostly pili II negative [12,34,56]. Recently, experimental support for pili II-mediated attachment to uroepithelial cells came from a mouse model: Hagberg et al demonstrated with E. coli strains which were genetically manipulated to express defined adhesins, that MR pili-bearing bacteria efficiently infected the mouse kidney whereas strains expressing only MS pili did not colonize the urinary tract except the bladder [13,14].…”