Prevalence and antimicrobial susceptibility of enterotoxigenic Bacteroidesfragilis in children with diarrhoea in Nicaragua

Enterotoxigenic Bacteroides fragilis (ETBF) strains have been reported as a cause of diarrhoeal diseases. Diarrhoea is an important cause of morbidity and mortality in children from developing countries. This study was conduc ted to determine the prevalence and antimicrobial susceptibility of ETBF in children from Leon, Nicaragua. Faecal specimens from 106 children under te n years of age with diarrhoea and 60 asymptomatic, age-matched controls wer e examined for presence of ETBF using an assay based on immunomagnetic sepa ration (IMS) in combination with PCR (IMS-PCR) and HT29/C1 cell assay. ETBF was present in nine children with diarrhoea (8.4%) and was more often iden tified in children less than or equal to 1 year (7/63, 11.1%) but all ETBF positive children were under 2 years of age. ETBF was isolated as the only pathogen in five of nine positive children (55.5%). The agar dilution metho d was used to determine the antimicrobial susceptibility pattern of the ETB F strains. All strains were resistant to ampicillin (range 8-1024 mg/L) and one strain was also resistant to clindamycin MIC 256 mg/L. All the other a ntimicrobial agents were active against the strains (MIC50 and MIC90): 8 an d 16 mg/L for cefoxitin, 0.004 and 0.008 mg/L for imipenem, 0.5 and 0.5 mg/ L for clindamycin and for metronidazole, 2 and 4 mg/L for chloramphenicol. A majority (77%) of the ETBF strains were beta-lactamase producers. (C) 200 0 Academic Press.