Abstract

Thiol broth and sodium polyanethol sulfonate (SPS) are reported to neutralize antimicrobial agents to support better growth of bacteria in blood exposed to antimicrobial agents. The effect has not been studied with S. typhi which is frequently the object of blood culture in Korea. In this study the effect was determined in vitro with artificial exposure of S. typhi to chloramhenicol, ampicillin, and cotrimoxazole. The following results were obtained. When chloramphenicol is present the growth of S. typhi in Thiol broth was somewhat worse than in Tryptic soy broth (TSB). In the presence of ampicillin or cotrimoxazole, the growth was better in Thiol broth and Thiol broth + SPS, and TSB and TSB + SPS, when chloramphenicol is present. The growth was slightly worse in the Thiol broth + SPS than in Thiol broth when 32㎍/㎖ of ampicillin is present; in Thiol broth + SPS than in Thiol broth when 32㎍/㎖ of cotrimoxasole is present; and in TSB + SPS than in TSB when 1㎍/㎖ of cotrimoxazole is present. It is concluded that Thiol broth neutralizes ampicillin and cotrimoxazole but not chloramphenicol and the use of Thiol broth may be beneficial if used in actual blood culture. SPS did not neutralize those antimicrobials.