Environmental fate of ceftiofur sodium, a cephalosporin antibiotic. Role of animal excreta in its decomposition

Heterogeneous photocatalytic degradation of pharmaceuticals in water by using polycrystalline TiO2 and a nanofiltration membrane reactor

“…Zuccato et al [8] carried out an extensive investigation on the presence of drugs in drinking and surface waters also in the Lombardy region of Italy. Transformation of antibiotics [7,[9][10][11] has been widely studied. At present only for few pharmaceutical substances (aspirin, caffeine, clofibrate, ciclofosphamide, oestrogens, ibuprofen, naproxen) literature information on the biodegradability are available [7,[12][13][14][15].…”

Bovine Intestinal Bacteria Inactivate and Degrade Ceftiofur and Ceftriaxone with Multiple β-Lactamases

“…After injection, ceftiofur is rapidly metabolized by kidney and liver esterases to desfuroylceftiofur, which allows it to be conjugated to cysteine and glutathione (33). Some observations suggest that primary metabolites of these polar conjugates may be rapidly degraded further by viable intestinal microbes to inactive metabolites, since fecal slurries from cattle rapidly degrade ceftiofur, but steam-sterilized fecal slurries do not (17). Metabolites of ceftiofur are predominantly eliminated in the urine (26).…”

“…In one study, the chemically unrelated antimicrobial drug tylosin was shown to be degraded by bovine fecal microbes with a half-life of 6.2 days (44). The half-life of ceftiofur in feces of cattle was too rapid to measure, and addition of feces to urine containing ceftiofur decreased the half-life from 23 to 17 h, indicating that a fecal component catalyzed degradation of the drug (17).…”

“…Ceftiofur does not persist in animal tissues, having a zero-day slaughter withholding interval (20). Ceftiofur breaks down in acidic and alkaline environments (25) and in soils (17). Additionally, the drug may be metabolized by microorganisms, which would also reduce its half-life in the environment.…”

“…The principle mechanism of microbial degradation of ceftiofur may be initiated by ␤-lactamases, which are heat-labile proteins, based on evidence that fresh feces from cattle but not autoclaved feces rapidly degrades ceftiofur (17). Hydrolysis of ceftiofur by ␤-lactamases is supported by several studies showing that these enzymes confer resistance to the drug (1,10,21).…”