Table 2 Colistin resistant isolates and mcr-3 and mcr-5.1 colistin resistance genes detected in river and storm water in the Western Cape of South Africa during 2019–2020
Sampling sites | Plankenburg river | Eerste river | Berg river | Muizenberg storm water | Fish Hoek storm water | |||||
|---|---|---|---|---|---|---|---|---|---|---|
P1 | P2a | P2b | E1 | E2 | B1 | B2 | B3 | M | FH | |
Sampling date | May 2019 | May 2019 | Jan 2020 | Jan 2020 | Jan 2020 | Jan 2020 | Jan 2020 | Jan 2020 | Nov 2019 | Nov 2019 |
Proportion of phenotypically colistin resistant colonies, n (%) | 496/620 (80%) | 5670/13000 (44%) | 7900/42000 (19%) | 400/1050 (38%) | 85,000/188000Â (45%) | 840/1350 (62%) | 14,700/186000Â (7.9%) | 540/1480 (36%) | 320/6400 (5%) | 170/940 (18%) |
Colistin resistant isolates (n, MIC) | Aeromonas jandei (3, MIC: 32), Aeromonas sobria (3, MIC: 32), Aeromonas hydrophila (2, MIC: 64), Pectobacterium carotovorum (1, MIC: 16) | Raoultella ornithinolytica (10, MIC: 64), Franconibacter helveticus (2, MIC: 64), Kluyvera ascorbata (2, MIC:16), Citrobacter freundi (1, MIC:16), Klebsiella oxytoca (1, MIC:16), Pantoea agglomerans (1, MIC:16), Pluralibacter gergoviae (1, MIC:16)) | Aeromonas hydrophila (11, MIC: 64), Salmonella enterica (1, MIC: 64) | Aeromonas hydrophila (2, MIC: 64) | Aeromonas hydrophila (11, MIC: 32 or 64), Klebsiella oxytoca (1, MIC:4) | Aeromonas jandei (5, MIC: 64), Raoultella ornithinolytica (4, MIC: 4 or 64), Aeromonas hydrophila (3, MIC: 32 or 64), Klebsiella oxytoca (1, MIC: 8), Pectobacterium carotovorum (1, MIC: 16) | Aeromonas hydrophila (3, MIC: 64) | Aeromonas hydrophila (5, MIC: 64), Aeromonas veronii (4, MIC: 4 or 8), Aeromonas sobria (3, MIC: 4), Aeromonas jandei (1, MIC: 4) | Aeromonas hydrophila (13, MIC: 32 or 64) | Aeromonas hydrophila (1, MIC: 64), Enterobacter kobei (1, MIC: 64) |
Number of isolates of each species in which mcr genes were detected (n) | None detected | None detected | None detected | None detected | None detected | A. jandei mcr-3.33 (1) mcr-3.34 (1) mcr-3.35 (1) mcr-3.36 (2) | None detected | A. veronii mcr-3.37 (1) | None detected | None detected |
mcr genes detected directly from the water sample (eDNA) | None detected | mcr-3 mcr-5.1 | mcr-3 mcr-5.1 | None detected | mcr-3 mcr-5.1 | mcr-3 | None detected | mcr-3 mcr-5.1 | mcr-3 mcr-5.1 | mcr-5.1 |