[Correlations between lactose-fermenting capacity, sensitivity to antibiotics and bacteriophage types of Salmonella...

Correlation between the ability to ferment lactose, sensitivity to chemotherapeutic agents and phage type of lactose fermenting and nonfermenting S. agona strains was shown in this study. The difference in sensitivity of two S. agona variants toward gentamicin, tobramycin and chloramphenicol was shown. Lactose fermenting S. agona strains were resistant to the above listed antibiotics. The percentage of the resistant strains was 95.3%, 96.9% and 95.3%, respectively. S. agona strains typable by biochemical tests were more often sensitive to those antibiotics. The percentage of the resistant strains of S. agona with typical biochemical properties was for gentamicin 19.4%, tobramycin 3.7% and chloramphenicol 6.7%. Moreover, the percentage of lactose fermenting S. agona strains resistant to seven other out of seventeen tested antibiotics was 83.8% on average and it was 20% higher than percentage of biochemically typical S. agona strains resistant to the same antibiotics. Lactose fermenting S. agona strains belonged almost four times more frequently to subtype VB and also more often to phage type XI; on the other hand six times rare to phage type I in comparison to biochemically typical S. agona strains.