RT Journal Article SR Electronic(1) A1 Brown, D. F. J. A1 Warner, M. A1 Taylor, C. E. D. A1 Warren, R. E.YR 1988 T1 Prospective addition of β-lactamase to blood culture medium JF Journal of Medical Microbiology, VO 26 IS 2 SP 147 OP 152 DO https://doi.org/10.1099/00222615-26-2-147 PB Microbiology Society, SN 1473-5644, AB SUMMARY The value of adding β-lactamase to bottles of blood-culture medium before their distribution to wards was investigated. Significantly more bottles containing β-lactamase were culture-positive than those without (p< 0.002). In another series, when the enzyme was added to both bottles in each set there was no significant difference in isolation rates between the two bottles. The groups of organisms which were isolated more readily when β-lactamase was present were staphylococci and streptococci. Storage of β-lactamase (Genzyme broad-spectrum mixture) in blood-culture medium at room temperature resulted in rapid loss of cephalosporinase activity, whereas little decline in penicillinase activity was noted over a period of 118 days., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/00222615-26-2-147