Table 5. Comparison of antibiotic resistance among Salmonella spp., Shigella spp., and all bacterial isolates.
| Antibiotic | Feb 2003-Feb 2004 Resistant Isolates# | Jul 2006-Jul 2008 Resistant Isolates# | p-value* |
| Salmonella spp. | |||
| Ampicillin | 19/46 (41) | 43/87 (49) | 0.465 |
| Trimethoprim-Sulfamethoxazole | 16/46 (35) | 19/86 (22) | 0.148 |
| Chloramphenicol | 14/25 (56) | 5/82 (6) | <.001 |
| Nalidixic Acid | 4/25 (16) | 22/87 (25) | 0.426 |
| Shigella spp. | |||
| Ampicillin | 32/74 (43) | 66/80 (83) | <.001 |
| Trimethoprim-Sulfamethoxazole | 60/74 (81) | 62/80 (78) | 0.692 |
| Chloramphenicol | 6/16 (38) | 21/79 (27) | 0.378 |
| Nalidixic Acid | 0/16 (0) | 8/80 (10) | 0.345 |
| All Bacterial Isolates ( Salmonella, Shigella , Campylobacter , E. coli ) † | |||
| Ampicillin | 56/127 (44) | 125/189 (66) | <.001 |
| Trimethoprim-Sulfamethoxazole | 82/127 (65) | 97/187 (52) | 0.028 |
| Chloramphenicol | 21/51 (41) | 31/182 (17) | 0.001 |
| Nalidixic Acid | 6/43 (14) | 37/189 (20) | 0.515 |
# Number (and %) of organisms resistant.
*p-values calculated using two-tailed Fisher Exact Test.
†This section includes all bacterial isolates (Salmonella spp.and Shigella spp.as well as the few isolates of Campylobacter spp. and E.coli). This summary section may be a useful guide to empiric therapy of dysentery in Southern Botswana.