Role and clinical course of verotoxigenic Escherichia coli infections in childhood acute diarrhoea in Argentina

Abstract

The aim of this study was to investigate the role and clinical course of verotoxigenic Escherichia coli (VTEC) infections in children with acute diarrhoea from Argentina, the country with the highest worldwide incidence of haemolytic uraemic syndrome (HUS). To accomplish this objective, 437 samples from children up to 6 years old with acute diarrhoea were collected and processed. More than 60 % of the children studied presented watery or mucous diarrhoea without blood, and in 25.2 % of the cases the samples contained blood. In a first screening, a multiplex PCR was performed to detect the presence of the vt 1 , vt 2 , eae, ehxA and saa virulence genes. The strains were then isolated and analysed to characterize their serotypes, virulence genes, antibiotic susceptibility profiles and verotoxin (VT) production. Forty-four of the 437 samples (10.1 %) were positive for VTEC virulence genes. VTEC-infected patients presented different types of diarrhoea (27.3 % belonged to the non-bloody type). Several serotypes and virulence genotypes were found. Isolates belonged to the serotypes O157 : H7, O145 : H " , O26 : H11, O121 : H19, O111 : H2 and O118 : H2. HUS developed in 16 (36.4 %) patients positive for VTEC virulence genes. All of the VTEC isolates produced a cytopathic effect on Vero cell monolayers, confirming the ability to express VT. Despite most strains being sensitive to all of the antimicrobials studied, a positive association between clinical progression to HUS and antibiotic therapy was observed for the total number of patients studied, as well as for the VTEC + group. In conclusion, the data obtained in this study increase our knowledge of the role and clinical course of VTEC infection in childhood acute diarrhoea beyond bloody diarrhoea, and might be considered for the prevention, diagnosis and management of this disease. It is possible that the optimal approach for VTEC diagnosis could be using multiplex PCR to search for the presence of the vt 1 , vt 2 , eae and ehxA genes.

Incidence and Virulence Determinants of Verocytotoxin-Producing Escherichia coli Infections in the Brussels-Capital Region, Belgium, in 2008–2010

“…This observation is in line with findings in neighboring countries, such as The Netherlands (60), Germany (2), France (51), Spain (5), and Switzerland (26,27). In contrast to the situation in these continental European countries, the proportions of O157 and non-O157 infections are thought to be quite different in North America, Argentina, and the United Kingdom (53,55). Yet a recent study by Hedican et al showed that non-O157 infections may account for as many as 53% of human VTEC isolates in the United States (19).…”

Antibiogram of E. coli serotypes isolated from children aged under five with acute diarrhea in Bahir Dar town

“…In the present study the isolation rate of E. coli serotype O157:H7 was 28.9 %, which is lower than the isolation rate documented by Rivas et al 28 and Rivero et al 29 . These differences could be due to sampling of children with different types of acute diarrhea, rather than the study being oriented towards bloody diarrhea or to children in contact with hemolytic uremic syndrome (HUS) patients.…”

Recent Advances in Understanding Enteric Pathogenic Escherichia coli

“…It should be noted that the ECDC/EFSA recommends not comparing incidences between countries due to differences in detection. STEC is also prevalent in developing countries such as Argentina, which has been described in the literature to have the highest worldwide incidence of HUS in children under the age of 5 (197). This may be due to excessive exposure to known risk factors associated with STEC infections, including meat consumption, playing in recreational water, and poor personal hygiene (198).…”