Authors

  1. Kloth, Luther C. MS, PT, FAPTA, CWS, FACCWS
  2. Berman, Joseph E. MHS, PT
  3. Laatsch, Linda J. PhD, MT (ASCP) SM
  4. Kirchner, Phyllis A. BS, MT (ASCP) SH

ABSTRACT

OBJECTIVES: To evaluate cytotoxicity and bactericidal effects of chloramine-T.

 

METHODS: In vitro study of various concentrations and exposure times to preparations containing human fibroblasts or 1.5 x 108 colony forming units per milliliter (CFU/mL) of 3 gram-positive bacteria-Staphylococcus aureus, methicillin-resistant S aureus, and vancomycin-resistant Enterococcus faecalis-and 2 gram-negative bacteria-Escherichia coli and Pseudomonas aeruginosa-with and without fetal bovine serum present.

 

MAIN OUTCOME MEASURES: Percentage reduction of bacterial growth and percentage of viable fibroblasts 48 hours after exposure.

 

RESULTS: All gram-positive growth was reduced by 95% to 100%, regardless of dose, with or without serum. E coli (gram-negative; with/without serum) was reduced 94% to 100% at antiseptic concentrations of 300 and 400 ppm. At 200 ppm, E coli growth was fully inhibited without serum present and by 50% with serum. P aeruginosa (gram-negative) was not significantly affected under any conditions. At 100 and 200 ppm, cell viability remained greater than 90% under all experimental conditions. A 300-ppm, 3-minute exposure to chloramine-T resulted in cell viability of up to 70%, with longer exposures producing lower viabilities. Serum did not affect cell viability in any condition.

 

CONCLUSIONS: In vitro, chloramine-T at 200 ppm for 5 to 20 minutes was effective against 3 virulent gram-positive bacteria without fibroblast damage. At 300 ppm and 3 and 5 minutes, 30% of fibroblasts were damaged and 95% to 100 % of E coli were inhibited, respectively.