Assay of Antibacterial Activity in Serum

Abstract

Is the patient receiving the proper drugs? Is he being given sufficient amounts to eradicate the infection? Every physician asks himself these questions when faced with the antimicrobial treatment of a serious infection.In many well-defined bacterial infections, clinical experience alone can supply an adequate answer. However, with the changing behavior of microbes and the changing natural history of infectious processes, additional guidance is often welcome and sometimes essential for optimal therapy. It is the purpose of this communication to draw attention to a helpful laboratory test, the assay of antibacterial activity in serum of patients receiving antimicrobial drugs. The test is simple, inexpensive, can be learned by any laboratory in a short time and\p=m-\ifproperly interpreted\p=m-\can aid the physician in the management of severe infections.

Rapid radiometric serum test for antibiotic activity

“…Figures 2 through 4 show the radiometric dose-response curves for the various organisms encountered in the clinical samples. As expected, an inverse relationship between antibiotic Gentamicin-penicillin (1)…”

Variation in Performance of the Serum Bactericidal Test

“…Significant variation occurred in preparation of the dilutions of the test serum. Only two laboratories used 2.5 ml as their total final volume, as suggested by Jawetz (9). Fifteen employed a final volume of 1 ml; however, in one-fourth of these, this included a rather large bacterial inoculum of 0.4 to 0.5 ml.…”

Septic arthritis in sickle‐cell thalassemia

“…Base excess is important because the pH coefficient used is based on data from carbon dioxide-induced acidosis, whereas the acidosis of inflammatory synovial tissue results primarily from production of lactic acid (15,16). The details of the method will be presented elsewhere (28). Briefly, the position (P5,,) of the OHEC for the observed hemoglobin level in sickle-cell anemia is corrected for the effects of pH and base excess.…”