The Estimation of Penicillin in Blood Serum and Milk of Bovines after Intramuscular Injection

The persistence of penicillin G in the mammary gland when infused immediately after the last milking of lactation

“…It is not possible from this experiment to estimate the quantity of the antibiotic diffusing from the udder for it is known that the breakdown of free penicillin in the blood is rapid. Watts & McLeod (1946), Kelly & Bell (1947) and Morse (1948) have shown that a single intravenous infection of penicillin G will persist for only about 1 h. Since in the experiment described a blood level greater than 0-5 /tg/ml was maintained for at least 5 h it would appear that a substantial quantity of the antibiotic diffused into the blood within a few hours of the infusion. In humans a constant infusion of about 60 mg/h is required to maintain a blood level of about 0-1 /ig/ml (Goerner & Geiger, 1945;Smith & Harford, 1945).…”

Antibiotic Residue Detection in Milk - A Review

“…The ability of bacteria to produce acid, reduce dyes or produce a lawn of growth on agar media, has served as the basis for most tests used in the detection of antibiotics in milk. One of the earliest methods for detection of antibiotics (penicillin) in milk, based on acid production using sterile litmus, employed a culture of Streptococcus agalactiae (56). Samples were incubated at 37°C for 3 d and checked for color development.…”