New Tests Make Antibiotic Monitoring Easier
By Jan Suszkiw
April 25, 2008
Detecting antibiotics in the
environment could become easier to do, thanks to portable field kits developed
and validated by a team of scientists from the
Agricultural Research Service (ARS),
Abraxis, LLC and the Czech Republic.
The team conducted studies showing that the kits, called enzyme-linked
immunosorbent assays (ELISA), accurately detected trace amounts of
sulfonamides, also known as "sulfa drugs," in wastewater samples.
When these drugs are excreted in urine, for example, they can persist in the
environment unchanged or as metabolites.
Shelver and ARS physiologist
Shappellboth with the agency's
Research Laboratory in Fargo, N.D.conducted the validation studies in
collaboration with kit developers Milan Franek, with the
Research Institute in Brno, Czech Republic; and Fernando Rubio, with
Abraxis, LLC in Warminster, Pa.
Using antibodies developed by Franek, Rubio prepared the kits so that
farmers, wastewater plant operators, researchers and others could readily
perform onsite monitoring of sulfa drugs. Sewage plant operators, for example,
could use the kits to determine whether modifications to their treatment
regimens effectively prevent the drugs' discharge into waterways. Scientists
can use the kits to monitor the sulfonamides' fate and transport in soils.
Instrumentation now exists to detect and measure sulfa drug levels in
samples. However, dedicated space, high operating costs and specialized
training make such methods impractical for field use. The kits, in contrast,
are easy to use, require minimal training, and produce results quickly,
according to Shelver.
In tests using samples from two wastewater treatment plants, as well as
samples obtained by Shappell from swine-rearing facilities, Shelver used liquid
chromatography-mass spectrometry (LC-MS) instrumentation to verify the kits'
accuracy in detecting two widely used sulfa drugssulfamethoxazole and
sulfamethazine. Shelver believes the kits are a more flexible complement to
LC-MS-based detection methods and particularly useful for situations requiring
routine environmental monitoring.
ARS is the U.S. Department
of Agriculture's chief scientific research agency.