Impact of Chronic Tetracycline Exposure on Human Intestinal Microbiota in a Continuous Flow Bioreactor Model.

Studying potential dietary exposure to antimicrobial drug residues via meat and dairy products is essential to ensure human health and consumer safety. When studying how antimicrobial residues in food impact the development of antimicrobial drug resistance and disrupt normal bacteria community structure in the intestine, there are diverse methodological challenges to overcome. In this study, traditional cultures and molecular analysis techniques were used to determine the effects of tetracycline at chronic subinhibitory exposure levels on human intestinal microbiota using an in vitro continuous flow bioreactor.

Determination of Chloramphenicol and Nitrofuran Metabolites in Cobia, Croaker, and Shrimp Using Microwave-Assisted Derivatization, Automated SPE, and LC-MS/MS-Results from a U.S. Food and Drug Administration Level Three Inter-Laboratory Study.

Background: An interlaboratory study was conducted to test a published, peer-reviewed manuscript in the Journal of AOAC INTERNATIONAL Vol 98, No. 3, 2015, "Quantitation of Chloramphenicol and Nitrofuran Metabolites in Aquaculture Products Using Microwave-Assisted Derivatization, Automated Solid-Phase Extraction, and LC-MS/MS."

Objective: The purpose of this study was to demonstrate the performance of the method in shrimp, cobia, and croaker matrices.

In vitro test systems to determine tetracycline residue binding to human feces.

The use of antimicrobials, such as tetracycline, in food-producing animals may result in antimicrobial drug residues (ADR) in edible tissues from treated animals and contribute to the emergence of antibiotic resistant bacteria. The Veterinary International Conference on Harmonization (VICH) document (VICH GL36(R)/FDA-CVM Guidance for Industry#159) provides guidance on evaluating the safety of veterinary ADR in the human foods as related to effects on the human intestinal microbiome. One recognized research gap is a need for additional data and testing requirements to determine the fraction of an oral dose of ADR available to intestinal microorganisms.

Quantitative Screening Method for Erythromycin and Tylosin in Honey Using RapidFire Mass Spectrometry.

: Antibiotic resistance and other adverse health issues related to the presence of drug residues in honey are of great concern to the United States, United Kingdom, and many other countries. The majority of quantitative testing methods using mass spectrometry are not capable of performing high-throughput analysis. Furthermore, the methods that are available are labor intensive and time consuming.

Quantitation and Confirmation of Chloramphenicol, Florfenicol, and Nitrofuran Metabolites in Honey Using LC-MS/MS.

This paper describes a rapid and robust method utilizing a single liquid-liquid extraction for the quantitation and confirmation of chloramphenicol, florfenicol, and nitrofuran metabolites in honey. This methodology combines two previous extraction methods into a single extraction procedure and utilizes matrix-matched calibration standards and stable isotopically labeled standards to improve quantitation. The combined extraction procedure reduces the average extraction time by >50% when compared with previously used procedures.

RapidFire Mass Spectrometry with Enhanced Throughput as an Alternative to Liquid-Liquid Salt Assisted Extraction and LC/MS Analysis for Sulfonamides in Honey.

The use of veterinary drugs in honey bees for the prevention of infectious disease is ever increasing due to the spread of colony collapse disorder around the world. The United States Food and Drug Administration is concerned about the presence of these drugs residues in honey as they often lead to health concerns or potential antibiotic resistance. Currently there is a need for a rapid screening method for the detection of veterinary drugs in honey.

Quantitation of Chloramphenicol and Nitrofuran Metabolites in Aquaculture Products Using Microwave-Assisted Derivatization, Automated SPE, and LC-MS/MS.

This paper describes a rapid and robust method utilizing microwave-assisted derivatization, automated SPE, and LC-MS/MS for the quantitation and confirmation of chloramphenicol (CAP) and nitrofuran metabolites in various aquaculture matrixes. The use of equipment presented in this work allowed extractions to be completed on average within 6 h, with quantitation accuracy ranging from 89 to 107% and RSD≤8.3%.

In vitro enrofloxacin binding in human fecal slurries.

Most antibiotic inactivation studies have been conducted through in vitro incubations of human use aminoglycosides, beta-lactams, and fluoroquinolones, usually at fecal concentrations expected with therapeutic dose regimens in humans and animals. Less is known about the inactivation of these molecules when ingested at concentrations consistent with residue levels present in animal-derived foods from antibiotic treated animals. In this investigation, we used the fluoroquinolone, enrofloxacin which is specifically marketed for veterinary medicine as test compound.