Uncle Sam says it safe to eat burritos again.

The Centers for Disease Control and Prevention on Monday ended its three-month probe into the E. coli outbreaks at Chipotle Mexican Grill — but it did so without identifying the source of the illness.

While investors greeted the news by driving Chipotle’s shares up 4.3 percent, to close at $472.37, the CDC seemed more sober and appeared to take a swipe at Chipotle’s record keeping.

The outbreaks “appear to be over” the CDC said on its Web site, but added, “keeping detailed records” is an important key to preventing such outbreaks in the future.

The Food and Drug Administration, which assisted in the probe, “and the CDC must have been bothered by the fact that there wasn’t good record keeping” at the chain, said Bill Marler, a food safety lawyer who is representing a number of Chipotle customers who became ill.

The government agencies and Chipotle declined to elaborate on the company’s record keeping.

The Denver-based restaurant’s shares are down about 30 percent since October but it has been able to keep its core 13- to 24-year-old customers coming in, according NPD Group market research.