The Federal Select Agent Program dictates that all research entities in the United States must rigorously assess laboratory protocols to sterilize samples being removed from containment areas.
In this paper, researchers from the University of Florida in Orlando describe their experience conducting studies in which serum, plasma, bronchoalveolar lavage (BAL) fluid, or spent media must be transferred from the BSL-3 to the BSL-2 laboratory to conduct specific assays. These samples must be sufficiently intact so that they can evaluate drug, cytokine, chemokine, or enzyme levels and other host or bacterial components of interest. In most instances, chemical inactivation of the samples is not advisable.
The researchers validated procedures using sterile filtration and methanol to remove the following select agents: Francisella tularensis, Burkholderia pseudomallei, B. mallei, Yersinia pestis, and Bacillus anthracis. They also validated methanol treatment for B. pseudomallei.
Measuring the intracellular levels of antimicrobial drugs in the bronchoalveolar lavage (BAL) fluid is sometimes necessary to determine the amount of compound penetrating the site of infection within the cell. When it is necessary to measure the intracellular concentration, they treat the BAL cell pellet and the BAL fluid as 2 independent samples. Because the cell pellet sample cannot be filtered, they describe an additional procedure for removing BAL cell pellets from the containment laboratory.
These validations reaffirm safety protocols that enable researchers to keep samples sufficiently intact when samples are transferred between laboratories.
Validated Methods for Removing Select Agent Samples from Biosafety Level 3 Laboratories. Emerging Infectious Diseases, October 5, 2020.