DiarrhoeagenicEscherichia coliandEscherichia albertiiin Brazil: pathotypes and serotypes over a 6-year period of surveillance

Abstract

AbstractDiarrhoeagenicEscherichia coli(DEC) is a leading cause of infectious diarrhoea worldwide. In recent years,Escherichia albertiihas also been implicated as a cause of human enteric diseases. This study describes the occurrence ofE. colipathotypes and serotypes associated with enteric illness and haemolytic uremic syndrome (HUS) isolated in Brazil from 2011 to 2016. Pathotypes isolated included enteropathogenicE. coli(EPEC), enteroaggregativeE. coli(EAEC), enterotoxigenicE. coli(ETEC), enteroinvasiveE. coli(EIEC) and Shiga toxin-producingE. coli(STEC). PCR of stool enrichments for DEC pathotypes was employed, andE. albertiiwas also sought. O:H serotyping was performed on all DEC isolates. A total of 683 DEC and 10E. albertiistrains were isolated from 5047 clinical samples. The frequencies of DEC pathotypes were 52.6% (359/683) for EPEC, 32.5% for EAEC, 6.3% for ETEC, 4.4% for EIEC and 4.2% for STEC. DEC strains occurred in patients from 3 months to 96 years old, but EPEC, EAEC and STEC were most prevalent among children. Both typical and atypical isolates of EPEC and EAEC were recovered and presented great serotype heterogeneity. HUS cases were only associated with STEC serotype O157:H7. TwoE. albertiiisolates belonged to serogroup O113 and one had thestx2f gene. The higher prevalence of atypical EPEC in relation to EAEC in community-acquired diarrhoea in Brazil suggests a shift in the trend of DEC pathotypes circulation as previously EAEC predominated. This is the first report ofE. albertiiisolation from active surveillance. These results highlight the need of continuing DEC andE. albertiisurveillance, as a mean to detect changes in the pattern of pathotypes and serotypes circulation and provide useful information for intervention and control strategies.