Table 3.
Comparison of antimicrobial resistance by toxin variant types of C. difficile strains.
| Resistance phenotype | Toxigenic strains | Nontoxigenic strains | p-value# | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| A+B+ CDT+(n = 4) | A+B+ CDT−(n = 15) | A+B+ CDTA+B−(n = 5) | A+B− CDT+(n = 1) | A−*B+CDT+(n = 16) | A−*B+ CDT−(n = 19) | A−*B+ CDTA+B−(n = 8) | A−*B−CDT+(n = 1) | A−*B−CDT−(n = 1) | A−B−CDT−(n = 1) | ||
| Metronidazole (n = 3) | – | 1 (6.7) | – | – | 2 (12.5) | – | – | – | – | – | 1.000 |
| Clindamycin (n = 58) | 4 (100) | 12 (80.0) | 3 (60.0) | 1 (100) | 16 (100) | 14 (73.7) | 7 (87.5) | – | – | 1 (100) | 1.000 |
| Ceftriaxone (n = 49) | 2 (50.0) | 9 (60.0) | 2 (40.0) | 1 (100) | 13 (81.3) | 13 (68.4) | 7 (87.5) | 1 (100) | – | 1 (100) | 0.724 |
| Erythromycin (n = 63) | 3 (75.0) | 14 (93.3) | 4 (80.0) | 1 (100) | 16 (100) | 16 (84.2) | 7 (87.5) | – | 1 (100) | 1 (100) | 0.613 |
| Rifampicin (n = 65) | 3 (75.0) | 15 (100) | 3 (60.0) | 1 (100) | 16 (100) | 17 (89.5) | 8 (100) | – | 1 (100) | 1 (100) | 0.492 |
| Ciprofloxacin (n = 61) | 4 (100) | 13 (86.7) | 4 (80.0) | 1 (100) | 15 (93.8) | 13 (68.4) | 8 (100) | 1 (100) | 1 (100) | 1 (100) | 0.257 |
| Tetracycline (n = 36) | 2 (50.0) | 9 (60.0) | 3 (60.0) | 1 (100) | 11 (73.3) | 5 (26.3) | 4 (50.0) | – | – | 1 (100) | 0.080 |
| MDR (n = 61) | 3 (75.0) | 14 (93.3) | 3 (60.0) | 1 (100) | 16 (100) | 14 (73.7) | 8 (100) | – | 1 (100) | 1 (100) | 0.196 |
| MDR patterns | |||||||||||
| Three classes (n = 6) | – | 4 (26.7) | – | – | – | – | 1 (12.5) | – | 1 (100) | – | 0.030 |
| Four classes (n = 6) | – | 2 (13.3) | 1 (20.0) | – | 1 (6.3) | 2 (10.5) | – | – | – | – | 1.000 |
| Five classes (n = 26) | 1 (25.0) | 5 (33.3) | 2 (40.0) | – | 6 (37.5) | 8 (42.1) | 4 (50.0) | – | – | – | 0.728 |
| ≥Six classes (n = 23) | 1 (25.0) | 4 (26.7) | – | 1 (100) | 9 (56.3) | 4 (21.1) | 3 (37.5) | – | – | 1 (100) | 0.709 |
A− *: isolates in which the tcdA gene had a 110 bp deletion compared to the wildtype tcdA gene. CDT+: isolates harboured both cdtA and cdtB genes of the binary toxin. CDTA+B−: isolates only harboured the A component of the binary toxin. #P-value the result of a two-tailed Fishers exact test comparing A+B+CDT− isolates to A−*B+CDT− isolates. MDR, Multidrug-resistant.