article · Toxins
A study of 38 Shiga toxin-producing Escherichia coli (STEC) isolates implicated in human illness between 2006 and 2013 in South Africa evaluated their serotypes, virulence genes, drug resistance, and genetic relatedness. The isolates comprised 11 distinct O:H serotypes, dominated by non-O157 strains including O26:H11 (24 percent), O111:H8 (16 percent), and O117:H7 (13 percent), alongside O157:H7 (13 percent). Most strains carried critical virulence genes such as stx1, eaeA, and ehxA, with fewer harbouring stx2. Furthermore, 89 percent of the isolates showed multidrug resistance. Genetic profiling using pulsed-field gel electrophoresis identified 34 profiles grouping into eight clusters with at least 80 percent similarity within serotypes, regardless of collection year. Overall, the findings demonstrate that South African human infections predominantly involved multidrug-resistant, non-O157 strains carrying typical virulence factors, pointing to a need for stronger national monitoring and surveillance programmes.
Shiga toxin-producing Escherichia coli can trigger mild to severe illness in humans. By revealing that most local cases involved non-O157 strains rather than classic O157 strains, and that nearly nine in ten were multidrug-resistant, this work highlights the need for public health systems to track a wider range of bacterial strains and maintain alert surveillance frameworks to effectively identify and manage outbreaks.
The abstract points to a public health need for improved monitoring and surveillance programmes rather than a commercial product. The data could inform diagnostic developers seeking targets for multi-strain STEC assays or surveillance tools capable of identifying non-O157 serotypes and resistance profiles. However, as descriptive epidemiological research analysing historical bacterial isolates, this work remains at an early diagnostic research stage, and the abstract indicates no direct commercialisation pathway.
AI-generated from the published abstract. Always read the original work before citing.
Shiga toxin-producing <i>Escherichia coli</i> (STEC) isolates (N = 38) that were incriminated in human disease from 2006 to 2013 in South Africa were characterized by serotype, virulence-associated genes, antimicrobial resistance and pulsed-field gel electrophoresis (PFGE). The isolates belonged to 11 O:H serotypes. STEC O26:H11 (24%) was the most frequent serotype associated with human disease, followed by O111:H8 (16%), O157:H7 (13%) and O117:H7 (13%). The majority of isolates were positive for key virulence-associated genes including <i>stx1</i> (84%), <i>eaeA</i> (61%), <i>ehxA</i> (68.4%) and <i>espP</i> (55%), but lacked <i>stx2</i> (29%), <i>katP</i> (42%), <i>etpD</i> (16%), <i>saa</i> (16%) and <i>subA</i> (3%). <i>stx2</i> positive isolates carried <i>stx2c</i> (26%) and/or <i>stx2d</i> (26%) subtypes<b>.</b> All pathogenicity island encoded virulence marker genes were detected in all (100%) isolates except <i>nleA</i> (47%), <i>nleC</i> (84%) and <i>nleD</i> (76%). Multidrug resistance was observed in 89% of isolates. PFGE revealed 34 profiles with eight distinct clusters that shared ≥80% intra-serotype similarity, regardless of the year of isolation. In conclusion, STEC isolates that were implicated in human disease between 2006 and 2013 in South Africa were mainly non-O157 strains which possessed virulence genes and markers commonly associated with STEC strains that have been incriminated in mild to severe human disease worldwide. Improved STEC monitoring and surveillance programs are needed in South Africa to control and prevent STEC disease in humans.
This page summarises published work. The authoritative version sits with the publisher.
DOI: 10.3390/toxins11070424
Is something wrong with this record? Report it or request removal.
Discussion
Have you built on this work, tried to replicate it, or seen it applied in practice? Share what you know. Verified researchers and MARATTO™ domain experts can open a discussion, and any member can reply. Contributions are reviewed before they appear.
No discussion yet. Open the first thread.
New to MARATTO™? Create a free account.
