Table 1: Results of transfer experiments and minimum inhibitory concentrations (MICs) of antibiotics for donors
and transconjugants
|
Set No. |
Donor strain |
Recipient strain |
T ransconj ugant |
Conjugation |
MICs (m g/ml) of T ransconj ugant |
|
I |
S. typhi BS13 |
E. coli C600 (Nx) |
E. coli C600 [pBS13] |
0.83 × 10-5 |
A (5000) |
|
E. coli C600 |
S. typhi B72 |
S. typhi B72 [pBS13] |
0.68 × 10-7 |
A (5000) | |
|
II |
S. typhi AS12 |
E. coli C600 |
E. coli C600 [pAS12] |
0.73 × 10-5 |
A (5000) |
|
E. coli C600 |
S. typhi B72 |
S. typhi B72 [pAS12] |
0.12 × 10-6 |
A (5000) | |
|
III |
S. typhi M54 |
E. coli C600 |
E. coli C600 [pM54] |
0.78 × 10-5 |
A (2000) |
|
E. coli C600 |
S. typhi B72 |
S. typhi B72 [pM54] |
0.38 × 10-7 |
A (2000) | |
|
IV |
S. typhi B2/92 |
E. coli C600 |
E. coli C600 [pB2/92] |
0.89 × 10-5 |
A (2000) Co (500) |
|
E. coli C600 |
S. typhi B72 |
S. typhi B72 [pB2/92] |
0.62 × 10-7 |
A (2000) Co (500) | |
|
V |
S. typhi D1/01 |
E. coli C600 |
E. coli C600 [pD1/01] (ACCoTNx) |
0.39 × 10-5 |
A (1800) C (1500) Co (25θ) T (250) |
|
E. coli C600 [pD1/01] |
S. typhi B72 |
S. typhi B72 |
0.48 × 10-7 |
A (1800) C (1500) Co (25θ) T (250) |
A=ampicillin, C=chloramphenicol, Co=Cotrimoxazole, T=tetracycline, Nx=nalidixic acid,p=plasmid
In another experiment, the S. typhi strain D1/01, having the resistance pattern of ACCoTNx, transferred the ACCoT-
resistance to the antibiotic sensitive S. typhi strain through E. coli C600, indicating the non-transferability of Nx-
resistance from D1/01 strain (Table 1).
Transfer of Resistance from E. coli, K. pneumoniae and P. vulgaris to S. typhi
In this study, the MDR E. coli, K. pneumoniae and P. vulgaris strains transferred ACCoT-resistance to the recipient
strains (Table 2).