The Food and Drug Administration has okayed Hillandale Farms, one of two Midwest egg producers at the center of this summer's massive egg recall, to sell shell eggs again. But Wright County Egg was sternly warned to take corrective action to its facilities or be seized.

The Food and Drug Administration is allowing Hillandale Farms, based in Gettysburg, Pa., to again sell shell eggs. But the other producer, Wright County Egg, was issued a scathing warning letter, threatening that if corrective action isn’t taken, the FDA could seize company assets.

In the letter, Quality Egg, the parent company of Wright County Egg, was told that FDA inspectors found “serious deviations” from salmonella regulations at the company’s plants in Clarion, Dows and its Galt, Iowa, headquarters. Potential salmonella contamination led to the recall of more than half a billion eggs and illnesses for more than 1,600 people.

Among others, the observations that particularly concern the FDA include Wright’s failure to get rid of rodent nesting sites, failure to properly seal its henhouses, failure to eliminate sources of water in the manure pits below the henhouses, failure to require employees to “change protective clothing when moving from house to house,” failure to keep un-caged chickens out of the egg-laying operation and the discovery of live mice, live and dead flies and live and dead maggots “too numerous to count” in the henhouses.

FDA inspectors continue to monitor activities at Wright County Egg, says FDA spokeswoman Patricia El-Hinnawy.

After being tested extensively, three Hillandale Farms of Iowa’s egg-producing houses have been found to have no evidence of salmonella, according to the FDA.