Escherichia coli enterohemorrágica en el síndrome hemolítico urémico, en niños chilenos: evaluación de diferentes técnicas de diagnóstico de infección / Enterohemorrhagic escherichia coli in hemolytic uremic syndrome, in chilean children: evaluation of different technics of infection diagnosis

Enterohemorrhagic escherichia coli (EHEC), have been associated with pathogenesis of hemolytic uremic syndrome (HUS) worldwide. Our aim was to determine the association of EHEC ing¿fection and HUS in chilean children. During may 1991 and october 1993, 34 children HUS and 33 age matched controls (children with diarrhea that did not develop HUS) were enrolled in a case/control study. For each child a stool and serum sample were obtained at admission. Stools were processed for common enteropathogen and for EHEC identification. EHEC were identified in stools by gene probes for different virulence factors (EHEC plasmid-associated fimbria, Shiga-like toxin I, Shiga-like toxin II and eae adherence factor) and by detection of free fecal toxin by neutralization assay in Vero cells. Sera were processed for anti-cytotoxin antibodies also by an assay in Vero cells. Enteropathogens were isolated in 20.6 percent and 15.5 percent of HUS and control children respectively (p=NS). 91 percent of the HUS children and 73 percent of the control children were EHEC positive by one or more of the techniques used (p=0.05). Of the 3 detection methods used for EHEC, only free fecal cytotoxin was significantly more common in HUS children than controls (45.5 percent vs 9 percent p=0.007). Genotype patterns of HUS and controls strains were similar except for a trend towards a higher frequency of non-toxigenic strains in the control group. Serogroup 0157 was more common in HUS children than in controls (9 percent vs 0 percent p=0.036). In Chile as in other countries, EHEC infection is common and significantly associated with occurrence of HUS. Infection with EHEC strains 0157 seems to be important risk factor for HUS

Grupo sanguíneo P1 y su relación con cicatriz renal en pacientes con infección urinaria / Blood group P1 and its relation to renal cicatrix in patients with urinary infection

En los últimos años se ha insistido en la relación que existiría entre la infección urinaria, la cicatriz renal y el subgrupo sanguíneo P. La infección urinaria, producida la mayoría de las veces por determinados tipos de E. coli tendría importancia en el daño renal dado que la E. coli tiene capacidad de adherirse al epitelio urinario por medio de fimbrias, reconociendo un receptor de estructura química relacionada, a su vez con el subgrupo P. Determinamos el subgrupo P1 en 30 niños con infección urinaria, reflujo vesicoureteral y sin cicatriz renal, comparándolo con otro grupo de igual cantidad de pacientes portadores de infección urinaria y reflujo, pero con cicatriz renal. El grupo P1 se encontró presente en 66,7%de los pacientes sin daño renal y en 56,7%de los que tenían cicatriz renal. Así, pues, no logramos demostrar que el subgrupo P1 sirva como marcador indirecto de riesgo de formación de cicatriz renal, ya que no hubo diferencias entre los dos grupos de pacientes estudiados