Multilocus-based phylogenetic analysis of extended-spectrum beta-lactamase Escherichia coli O157:H7 uncovers related strains between agriculture and nearby water sources

• Main Authors: Cecilia Mahlatse Raseala, Mutshiene Deogratias Ekwanzala, Maggy Ndombo Benteke Momba
• Format: Article
• Language: English
• Published: Elsevier 2020-12-01
• Series: Journal of Infection and Public Health
• Subjects: Extended-spectrum beta-lactamases; Escherichia coli O157:H7; Agricultural environment; Water
• Online Access: http://www.sciencedirect.com/science/article/pii/S1876034120307139

This study aimed to uncover related strains of extended-spectrum beta-lactamase Escherichia coli O157:H7 between agricultural matrices (soil, manure and irrigation water) and nearby water sources using multilocus-based phylogenetic analysis. Resistant and nonresistant E. coli O157:H7 were isolated, identified and characterised using standard microbiological methods. The results showed that soil samples had a high prevalence of E. coli O157:H7 (31.73%) and ESBL-producing E. coli O157:H7 (22.11%). Multilocus sequencing typing (MLST) analysis revealed that all ESBL-producing E. coli O157:H7 were identified as ST11. Phylogenetic analysis of E. coli O157:H7 indicated that irrigation water might be a reservoir for E. coli O157:H7. For antibiotic-resistant genes (ARG), the most common was blaTEM in 85% (n = 34), followed by blaOXA in 70% (n = 28), blaNDM and sul1 30% (n = 12) and lastly mcr-1, which was only found in one soil isolate. The results showed that ESBL-producing E. coli O157:H7 isolates were intermixed in three clades, indicating close relatedness between isolated strains from different matrices.