Evaluation of thiol broth for the culture of Salmonella typhi and other bacteria from blood.

Thiol broth is known to neutralize various antimicrobial agents. Positivity of growth of various species of bacteria from blood in thiol broth was reported as similar to that in tryptic soy broth (TSB). As blood cultures are often used for the diagnosis of typhoid fever, and as patients may receive antimicrobial therapy before blood culture, the positivity and rapidity of growth of Salmonella typhi in thiol broth were compared to those in TSB. Routine blood culture samples from Yonsei Medical Center patients were inoculated in 50-ml amounts of TSB and thiol broth. The media were prepared from dehydrated products and did not contain CO2, but TSB contained 0.025% sodium polyanethol sulfonate (SPS). Growth of S. paratyphi-A, Klebsiella pneumoniae, Enterobacter sp., Serratia marcescens and alpha-hemolytic Streptococcus were similar in both media. However, greater positivity and shorter incubation time for macroscopic detection were noted in TSB with S. typhi, Escherichia coli and Staphylococcus aureus. It is concluded that thiol broth is inferior to TSB plus SPS for the culture of S. typhi from blood.