TABLE 1.
Antimicrobial susceptibility, cholera toxin production, PFGE patterns, and enterotoxigenicity in ctx+ V. mimicus strains
| Strain IDa |
Date of isolation |
Antimicrobial resistance (μg)b |
PFGE pattern |
CT productiond (ng ml−1) |
Suckling mouse assaye (n = 5) |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PB (50) |
CF (30) |
EM (15) |
ABPC (10) |
GM (10) |
Othersc | SfiI | NotI | LB | AKI | FA ratio | Diarrhea | ||
| V. mimicus DCT1 | 17 July 2000 | R | R | I | R | S | S | I | a | 0.3 | 0.1 | nd | nd |
| V. mimicus DCT2 | 05 August 2000 | R | R | I | R | S | S | II | a | 0.4 | 0.2 | 0.068 | 0/5 |
| V. mimicus DCT3 | 22 August 2000 | R | R | I | R | S | S | I | b | 0.2 | 0.1 | nd | nd |
| V. mimicus DCT4 | 11 September 2000 | S | R | I | R | I | S | III | b | 0.2 | 0.1 | nd | nd |
| V. mimicus DCT5 | 03 October 2000 | S | R | I | R | I | S | II | b | 110 | 30 | 0.087 | 5/5 |
| V. mimicus DCT6 | 27 October 2000 | S | R | I | R | I | S | II | a | 0.5 | 0.4 | nd | nd |
| V. cholerae 0395 | 1948 | S | I | S | R | S | 270 | 150 | 0.098 | 5/5 | |||
| V. cholerae N16961 | 1975 | R | S | S | I | S | 1.6 | 2.5 | nd | nd | |||
“DCT1” to “DCT6” represent V. mimicus strains examined in this study; “O395” and “N16961” represent V. cholerae reference strains of classical and El Tor biotypes, respectively. ID, identifier. Boldface highlighting indicates data from low-CT-producing V. mimicus strain DCT2 and from high-CT-producing V. mimicus strain DCT5.
“PB,” “CF,” “EM,” “ABPC,” and “GM” indicate polymyxin B, cephalothin, erythromycin, ampicillin, and gentamicin, respectively. S, R, and I designate susceptible, resistant, and intermediate patterns, respectively.
Others, other antibiotics (e.g., furazolidone, trimethoprim-sulfamethoxazole, nalidixic acid, ciprofloxacin, and tetracycline) were also used at standard doses (i.e., 100, 1.25/23.75, 10, 5, and 30 μg, respectively).
CT production was measured by bead-ELISA after cells were cultured (4 h static plus 4 h shaking, 120 revolutions min−1) in Luria-Bertani broth and AKI medium, representing inducible conditions for the classical and El Tor strain types, respectively. Mean values given are based on three experiments performed for each strain.
A fluid accumulation (FA) ratio of >0.08 in the suckling mouse assay indicates enterotoxigenicity. Mean values (n = 5) are given. nd, not done.