Chloramphenicol conjugates are comprised of small molecule chloramphenicol that is covalently bound to the protein bovine serum albumin (BSA). Typically, chloramphenicol conjugates are synthesized for competitive or direct enzyme-linked immunosorbent assay (ELISA) analysis, where the conjugation is coated on a microtiter and exposed to a biological analyte of interest. This enables chemists to detect the presence and concentration of the parent drug or its metabolites in a sample using a colorimetric recognition system, which assesses the level of material bound to the chloramphenicol conjugate on the surface of the well plate.
The exact methods of both competitive and direct ELISAs are explored in more detail here: EIA Method for Detecting Drugs of Abuse and Therapeutic Drugs. In this blog post, Pyxis explores the nature and importance of chloramphenicol conjugates in more detail.
The Development of Chloramphenicol Conjugates
Chloramphenicol is a broad-spectrum antibiotic that is readily used to treat bacterial infections of varying severity. The small-molecule drug was initially introduced as a treatment for typhoid fever, successfully reducing the fatality rate of the condition by inhibiting the growth of Salmonella Typhi in the intestinal tracts and bloodstreams of infected individuals. Unfortunately, the bacterium has grown resistant to numerous antibiotics including chloramphenicol. It is subsequently no longer utilized as the first-line of treatment for typhoid.
Oily chloramphenicol is a product comprising the drug in an oil-based suspension which was proposed as a suitable treatment for meningitis in 1975. A single intramuscular injection of the drug demonstrated long-lasting efficacy compared to standard therapy, which was gradually being rendered obsolete by bacterial resistivity. It also offered appreciable cost benefits compared to alternative antibiotics. However, the World Health Organisation (WHO) no longer recommends single-dose treatment with oily chloramphenicol to manage meningitis epidemics in low-income countries.
The withdrawal from chloramphenicol use is owed to the growing resistance of wider strains of bacteria and adverse side effects of the drug, such as aplastic anemia, bone marrow suppression, and grey baby syndrome. It is still perceived as an effective antibiotic by medical, veterinary, and animal husbandry professionals worldwide, but it is prescribed with caution. Use of chloramphenicol as a veterinary drug has been increasingly prohibited to minimize the risk represented to public health by excessive residue levels of toxic chloramphenicol metabolites propagating through the food chain.
Chloramphenicol conjugates were subsequently developed to determine the presence and concentration of the drug through immune detection via ELISA analysis. This may support the ongoing regulation of the drug as cumulative studies continue to highlight its potential carcinogenic effects.
Chloramphenicol Conjugates from Pyxis Labs
Pyxis Labs is one of the leading suppliers of analytical conjugations in the US. We synthesize reagents of extremely high purity and outstanding batch-to-batch reproducibility. Explore our full list of drug protein conjugations, including 01-CHLORB; our chloramphenicol conjugate which is formatted as a protein in water with a 0.01% sodium azide preservative.