Table 1.
Antibiotic sensitivity pattern of Clostridium tetani
| Isolates† | Zones of inhibition* | ||||||
|---|---|---|---|---|---|---|---|
| E | MZ | CFP | T | P | OFX | C | |
| C. tetani A | ≤ 0.1 (R) | 1.2 (S) | 1.0 (S) | 0.9 (S) | 1.0 (S) | ≤ 0.1 (R) | 0.7 (S) |
| C. tetani B | ≤ 0.1 (R) | 1.1 (S) | 1.0 (S) | 1.0 (S) | 1.3 (S) | ≤ 0.1 (R) | 0.7 (S) |
| C. tetani D | ≤ 0.1 (R) | 1.5 (S) | 1.5 (S) | 1.0 (S) | 1.2 (S) | ≤ 0.1 (R) | 1.5 (S) |
| C. tetani G | ≤ 0.1 (R) | 1.2 (S) | 1.5 (S) | 1.3 (S) | 0.9 (S) | ≤ 0.1 (R) | 1.4 (S) |
| C. tetani H | ≤ 0.1 (R) | 1.0 (S) | 0.7 (S) | 1.2 (S) | 1.0 (S) | ≤ 0.1 (R) | 0.8 (S) |
CFP = cefoperazone; C = chloramphenicol; E = erythromycin; MZ = metranidazole; OFX = ofloxacin; P = penicillin G; R = resistance; S = sensitivity; T = tetracycline.
Cutoff values for E and C are: ≥ 0.7 = susceptible and ≤ 0.3 = resistance, while the cutoff values for metronidazole, CFP, T, P, OFX include ≥ 1 = susceptible and < 0.5 = resistance, ≥ 0.5 = susceptible and ≤ 0.1 = resistance, ≥ 0.8 = susceptible and ≤ 0.2 = resistance, ≥ 0.8 = susceptible and ≤ 0.3 = resistance, and ≥ 0.7 = susceptible and ≤ 0.2 = resistance, respectively.
*
Zone of inhibition (measured in cm) to E, MZ, CFP, T, P, OFX, and C.
†
Five C. tetani strains isolated from the clinical samples of tetanus diagnosed patients.