Table 2.
Gram-negative CRB water isolates identified and characterized in this study.
| Isolate a | Closest Species Identified by BLAST of 16S rRNA Gene | CarbaNP c | CP d | Inhibition Zone (Diameter in mm) b | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| MEM | IMI | DOR | AMC | CFX | CIP | GTM | TET | ||||
| CP-M2-1 | Pseudomonas sp. 18 | − | N/D | 0 | 16.7 | 16.7 | 0 | 5 | 22.6 | 18.3 | 6 |
| CP-M2-3 | Pseudomonas plecoglossicida | − | N/D | 5.3 | 27 | 19 | 0 | 10 | 25.3 | 18.3 | 14 |
| CP-M2-4 | Pseudomonas putida | − | N/D | 0 | 26 | 14.5 | 0 | 4.3 | 22.7 | 21.3 | 12 |
| CP-M2-5 | Pseudomonas spp. GC04 | − | N/D | 0 | 28.3 | 20.8 | 0 | 3.7 | 26 | 26 | 12.3 |
| CP-M2-7 | Pseudomonas sp. CHZYR63 | − | N/D | 0 | 19 | 16.3 | 0 | 0 | 23.3 | 17 | 7 |
| SS-M2-1 | Pseudomonas sp. J4AJ | − | N/D | 18.7 | 24.7 | 20.6 | 10 | 25.3 | 38.8 | 24.7 | 25.3 |
| SS-M2-2 | Pseudomonas sp. P7 | − | N/D | 9.7 | 27.3 | 18.4 | 5.7 | 25.3 | 33 | 23.7 | 16 |
| SS-M2-3 | Aeromonas veronii | + | UNK | 7 | 8 | N/D | 8 | 35 | 39 | 25 | 25.3 |
| BBL-M2-1 | Aeromonas veronii | + | UNK | 24.7 | 20.7 | N/D | 15 | 36.7 | 36.7 | 20.3 | 27.3 |
| BBL-M2-2 | Stenotrophomonas maltophilia | + | bla L1 | 0 | 0 | N/D | 0 | 0 | 26.7 | 0 | 11.7 |
| BBL-M2-3 | Aeromonas veronii | + | UNK | 23.5 | 24.7 | N/D | 9 | 34 | 31.8 | 17.8 | 27 |
| MRP-M2-1 | Stenotrophomonas maltophilia | + | bla L1 | 0 | 0 | N/D | 0 | 0 | 26 | 7.3 | 10.7 |
| MRP-M2-2 | Pseudomonas sp. W15Feb40A | − | N/D | 19.8 | 30.7 | 28.5 | 3.3 | 15.3 | 24.7 | 22.8 | 16 |
| MRP-M2-3 | Pseudomonas putida | − | N/D | 17 | 29.7 | 27.3 | 0 | 15 | 31.3 | 23.3 | 19.3 |
| MRP-M2-4 | Pseudomonas fluorescens | − | N/D | 19.7 | 21 | 21 | 0 | 4.7 | 35.7 | 32 | 34 |
| MRP-M2-5 | Pseudomonas putida | − | N/D | 12 | 25.3 | 22 | 0 | 13 | 28.7 | 23.7 | 17.3 |
| RL-M2-1 | Pseudomonas rhodesiae | − | N/D | 0 | 13.5 | 13 | 0 | 3 | 36 | 30 | 21.7 |
| RL-M2-2 | Sphingobacterium siyangensis | − | N/D | 21.2 | 15.8 | N/D | 13.7 | 26 | 29.7 | 15 | 24.5 |
| WL-M2-1 | Enterobacter asburiae | + | bla IMI-2 | 2.2 | 0 | N/D | 0 | 32 | 35.7 | 21.3 | 23.3 |
| WL-M2-2 | Enterobacter asburiae | + | bla IMI-2 | 2.2 | 0 | N/D | 0 | 32.3 | 35.7 | 21.3 | 23.3 |
| WL-M2-3 | Enterobacter asburiae | + | bla IMI-2 | 2.2 | 0 | N/D | 0 | 31.7 | 36 | 21.7 | 24 |
| WL-M2-4 | Stenotrophomonas maltophilia | + | bla L1 | 0 | 0 | N/D | 0 | 0 | 26.7 | 13.3 | 10.8 |
a Isolate number: in regular font, isolates obtained directly using MacConkey-meropenem medium; in bold, isolates enriched in BLCVM9-meropenem medium before streaking in MacConkey-meropenem medium; in bold and italics, isolates enriched in BLCVM9-meropenem medium before streaking in Mueller–Hinton-meropenem medium. The initial(s) before the first dash in the isolate designation indicates the isolation location (Table 1). b Resistant (green), Intermediate (yellow), Susceptible (purple), based on the CLSI [48] or EUCAST [55] (for Pseudomonas spp.) breakpoint values of the diameters of the zone of inhibitions of each antibiotic. For genera that did not have diameter breakpoint values by CLSI or EUCAST, the Enterobacteriaceae cutoff values were used. N/D indicates that it was not tested. MEM (meropenem), IMI (imipenem), DOR (doripenem), AMC (amoxicillin plus clavulanic acid), CFX (cefotaxime), CIP (Ciprofloxacin), GTM (Gentamicin), TET (Tetracycline). c “−” and “+” indicate a negative or positive result, respectively, for the CarbaNP test. d Carbapenemase gene identified by PCR and sequencing. UNK (unknown) indicates lack of detection of a carbapenemase gene by PCR using blacphA, blaImiS, or blaVIM-2 primers.