ABTI's scientists extract and successfully test phages against Xanthamonas citri; the bacterial pathogen responsible for citrus canker

LEFT: ABTI's scientists extract and successfully test phages against Xanthamonas citri; the bacterial pathogen responsible for citrus canker.

MIDDLE: a microscopic image of the phage itself.

RIGHT: A phage "plaque" showing phage action against a culture of Xanthamonas citri bacteria. The clear spots show the progress of the phages as they utterly destroy the bacteria.

Successful Testing

Beginning in August 2010, ABTI sponsored a series of experiments in conjunction with the United States Department of Agriculture's Agricultural Research Service (USDA-ARS), which were designed to assess the efficacy of phage therapy in addressing the spread of citrus canker in Florida. An infection caused by the bacterial pathogen Xanthomonas citri, citrus canker causes blemishes on oranges, grapefruits and other citrus fruits which render them unmarketable and ultimately unsaleable. Since 1995, the U.S. federal government and the State of Florida have expended more than $US 1.4 billion addressing the spread of citrus canker; first, through an eradication program focused on the destruction of infected trees; then, through control efforts following the end of the eradication program in 2006.1

ABTI's team of Georgian scientists began by testing candidate phages provided by USDA-ARS. After these phages obtained less than satisfactory results when applied to a culture of Xanthomonas citri bacteria, USDA-ARS and ABTI obtained soil samples collected from the immediate vicinity of citrus trees in Florida. Within two days, ABTI's team extracted phages which scored a "direct hit" upon the Xanthomonas citri bacteria in laboratory results. Dr. John S. Hartung, Research Plant Pathologist for USDA-ARS, confirmed the success of this testing in the letter which is displayed to the right.

  • 1. Lowe, David. "Current Situation, Management, and Economic Impact of Citrus Canker in Florida." Uploaded to , 2009. Web.