Characterisation of STEC and other diarrheic E. coli isolated on CHROMagar™STEC at a tertiary referral hospital, Cape Town

BMC Microbiology

Karen H. Keddy¹  John Bosco Kalule²  Mark P. Nicol³ 

[1] Centre for Enteric Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa;Division of Medical Microbiology, Department of Pathology, Faculty of Health Sciences, University of Cape Town and National Health Laboratory Services, Cape Town, South Africa;Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

关键词: CHROMagar™STEC;    Tellurite resistant diarrhoeic E. coli;    STEC;    Shiga toxin;    Africa;   

DOI  :  10.1186/s12866-018-1195-7

学科分类：微生物学和免疫学

来源: BioMed Central

【 摘 要 】

Shiga toxin producing E. coli (STEC) is an emerging zoonotic pathogen that can cause acute renal failure, especially in children. Clinical microbiology laboratories may fail to detect STEC and other diarrhoeic E. coli unless purposive rigorous screening procedures are followed using appropriate diagnostic technology; CHROMagar™STEC has rarely been used for isolation of African diarrhoeic E. coli hence characteristics of isolates on this medium are not yet fully understood. This study aimed to determine the prevalence and characteristics of STEC and other diarrhoeic E. coli isolated on CHROMagar™STEC from stool samples submitted to the microbiology laboratory of a South African public sector tertiary care hospital. In total, 733 stool samples were tested. Of these, 4.5% (33/733) possessed diarrhoeic E. coli. Of the diarrheic E. coli, 5/33 (15.2%) were STEC, 15/33 (45.5%) EAggEC, 6/33 (18.2%) atypical EPEC, 5/33 (15.2%) typical EPEC, and 1/33 (3%) DAEC. None of the STEC isolates had been identified by routine testing (based on using sorbitol media to test for E. coli O157: H7 strains and not the other STEC) in the laboratory. Of the 33 strains, 55% (95% CI = 40.8–72.7) showed resistance to ampicillin. CHROMagar™STEC enabled detection of tellurite - resistant diarrhoeic E. coli that would be missed using routine methods. Further studies are needed to determine the proportion and characteristics of those which might have been missed using this approach.

【 授权许可】

CC BY