It was the kind of response you might expect from Donald Trump, not the president of the San Francisco Board of Supervisors.

David Cochrane of Dallas, visiting San Francisco with his wife, sent an email to Supervisor London Breed on July 25 complaining that there was way too much trash on city streets. “I was embarrassed to be an American because of the way San Francisco is presented to the world,” he wrote.

Four days later, Cochrane received a reply.

“If you are embarrassed to be an American, then you are barking up the wrong tree here, buddy,” the unsigned email from Breed’s office said. “Why don’t you write a letter to the editor of whatever town you’re from if your panties are in a bunch?”

Cochrane took the advice, but instead of contacting his local news outlet, he forwarded the response to The Chronicle.

Breed said Monday that the email had been written by an intern who has since been dismissed.

“The volunteer clearly showed extremely poor judgment and will not be continuing in my office,” Breed said in a statement.

“As with most legislative offices, we rely on volunteers. This is explicitly not how we train them to conduct themselves.”

Breed added, “I take full responsibility for the volunteer’s words and have personally apologized to Mr. Cochrane.”

She said the reply should have included an apology for the trash and a promise to notify the appropriate city officials.

In his email, Cochrane singled out Fisherman’s Wharf as “nasty” and added, “I will never return to your city and am telling everyone I know not to come to such a ‘dump.’”

Breed said Cochrane was right, too — the trash on the streets is unacceptable.

“It is embarrassing,” Breed said. “I called 311 four times this weekend because there was trash just sitting there. All over the city.”

After receiving Breed’s apology, Cochrane said in an email, “I am satisfied with her actions.”

— Emily Green

Emily Green is a San Francisco Chronicle. Email: cityinsider@sfchronicle.com, egreen@sfchronicle.com Twitter: @sfcityinsider, @emilytgreen