A clinical and bacteriological study of children suffering from haemolytic uraemic syndrome in Tucuman, Argentina.
Haemolytic uraemic syndrome (HUS) is a disease with serious consequences for children, such as terminal chronic renal failure. During the last few years there have been numerous studies undertaken to determine whether there is a relationship between this disease and the presence of Shiga toxin-producing bacteria. Escherichia coli (E. coli) O157:H7 is one of the most frequent etiologic agents of HUS. It acts through cytotoxins called Shiga toxin 1 (Stx1) and/or Shiga toxin 2 (Stx2) and carries a 90-Kb plasmid codified for an adhesion fimbria which is part of its pathogenicity. The objectives of this study were to: 1). confirm whether there exists a relationship between severity and clinical presentation of HUS; 2). prove the existence of Stx1 and/or Stx2 in the faeces of HUS patients; and 3). detect the presence of Stx1- and/or Stx2-producing E. coli. Our results did not show any difference in the average age, sex or clinical behavior between children with diarrhea positive (D+) HUS and diarrhea negative (D-) HUS. Male patients were predominant, as was incidence during summer, considering all cases. Nor could we find any relationship between severity and HUS type. E. coli O157:H7 was isolated in 40% of the patients with (D+) HUS and in 50% of patients with (D-) HUS. Another serotype, O55:K59, was also isolated (7%). Stx1 and/or Stx2 were found in all HUS cases. The following virulence factors of E. coli strains isolated from 12 patients were found: Adhesion fimbria (100%), Stx1 (16%), Stx2 (32%), and Stx1 + Stx2 (50%). None of these factors was found in control patients. Sixty-three percent of the HUS cases showed seroconversion for lipopolysaccharides of E. coli O157. We drew the following conclusions: 1). there is no significant relationship between seriousness of HUS and type of disease; 2). an association exists between HUS and the production of Stx1 and Stx2; 3). the incidence of E. coli O157:H7 was high in Tucuman, Argentina; and 4). Stx2 alone or in association with Stx1 was the predominant toxin.
Miceli
S
S
Servico de Nefrología, Hospital del Niño Jesús (Nephrology Department, Children's Hospital),Tucuman, Argentina.
Jure
M A
MA
de Saab
O A
OA
de Castillo
M C
MC
Rojas
S
S
de Holgado
A P
AP
de Nader
O M
OM
D001002:Anuria / Q000378:metabolism; D001118:Argentina / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004926:Escherichia coli / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000175:diagnosis* / Q000382:microbiology; D019453:Escherichia coli O157 / Q000302:isolation & purification; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D005260:Female; D006463:Hemolytic-Uremic Syndrome / Q000175:diagnosis* / Q000382:microbiology*; D006801:Humans; D006824:Hybridization, Genetic; D007223:Infant; D007668:Kidney / Q000473:pathology; D008070:Lipopolysaccharides / Q000378:metabolism; D008297:Male; D009846:Oliguria / Q000378:metabolism; D011446:Prospective Studies; D006435:Renal Dialysis / Q000379:methods; D012477:Salmonella enteritidis / Q000302:isolation & purification; D012486:Salmonella typhimurium / Q000302:isolation & purification; D022622:Shiga Toxin 1 / Q000032:analysis; D022641:Shiga Toxin 2 / Q000032:analysis
D008070:Lipopolysaccharides; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2