Shucking for safety: Galveston team helps keep processed oysters off the danger list

Call off the search for that “lost shaker of salt.” Not even a Jimmy Buffett song could sweeten what Texas A&M University at Galveston scientist Mona Hochman calls “oyster margaritas,” a revolting concoction mixed by the Seafood Safety Lab to test whether eating processed oysters could make consumers seriously ill or even die.

“Eating oysters can be dangerous,” she said. “Our lab aims to keep certain seafoods safe for the consuming public.”

Hochman, a senior lecturer in marine biology and honors program chair, is the senior research associate for the lab, which fills a unique role in monitoring the efficacy of oyster processing nationwide.

Her team has tested shrimp, crab, and catfish spines, but primarily works with oysters.

Post-harvest processing of oysters can reduce bacterial numbers through a variety of methods, including individually quick freezing, high hydrostatic pressure, pasteurization, and gamma irradiation. Regardless of the options used to prepare oysters for sale to restaurants and grocers, the Food and Drug Administration requires regular testing of these processes by an approved lab.

“Our lab is the only lab in the country that currently does that kind of work,” Hochman said.

Other labs across the nation respond to seafood safety concerns in their states by testing water and organisms for bacteria and viruses, Hochman explained. “But they don’t monitor what’s going through the oyster processing businesses.”

At the lab, two full-time staff members work with three to four credit-earning undergraduates a semester.

They test for two types of naturally occurring Vibrio bacteria, Hochman said. “They’ve been around here longer than we have, so they’re not the result of any sort of pollution.”

“The big baddie is Vibrio vulnificus,” she said. The rare systemic infection it causes spreads throughout the body, can feel like the flu and could prove deadly within 48 to 72 hours if not treated. Those with pre-existing conditions such as diabetes or immune deficiencies face the greatest risk.

The more common Vibrio parahaemolyticus can cause what Hochman describes as “the worst stomach flu you’ve ever had, but it goes on for days and days.” It’s not deadly unless the patient gets severely dehydrated and doesn’t seek treatment.

That less dangerous Vibrio played a pivotal role in putting Hochman in the roles she holds today.

She hadn’t intended to focus on microbiology when she arrived from Iowa at Texas A&M University at Galveston in 1989. Nor had she planned to wander back home to campus after graduating in 1994.

But as a sophomore, she was recruited to work in Dr. John Schwarz’s microbiology lab. Then, while finishing her master’s degree at the University of Maryland a few years later, she got a call from her former lab boss: “He’s like, ‘Hey, we just had this huge outbreak of Vibrio parahaemolyticus all over the country from Galveston Bay oysters. I need somebody to run my lab. Do you want to do it?’”

Hochman agreed to give it five years in 1998, but 28 trips around the sun later she is still shucking oysters, tossing them in a blender and pushing start.

“That’s how you get the bacteria out of them,” she said, explaining there’s no point in testing the shellfish individually.

“You could take 10 oysters next to each other off the reef and eight of them could have no detectable Vibrio while one has a couple thousand and another has over a million,” she said.

A dozen oysters make a sample, and companies must provide at least three samples. A few provide five. All the lab’s clients are on a quarterly testing cycle, but if one were to introduce a new processing method, the new approach would require a year of monthly testing with 100% clean results.

Hochman estimated the lab tests about 5,000 oysters a year and rarely finds anything concerning.

“So, we shuck a lot of oysters, but the good thing is we recycle all our shells with the Galveston Bay Foundation,” she said. The foundation, which also works with restaurants, cleans the shells and puts them back in the water to restore reefs.

The Seafood Safety Lab’s work only covers processed products, leaving fresh oyster aficionados to rely on cold water harvesting or cooking to make the shellfish safe to eat.

Note: The familiar adage about eating raw oysters in months with an ‘R’ doesn’t fully apply to those harvested along the Gulf Coast, where waters can remain warm and ripe with Vibrio bacteria well into October.

“From Nov. 1 until maybe March 30, that’s usually the ‘safe period’ in Galveston if they’re not processed,” Hochman said.

Ironically, she has never liked the taste of oysters, but she loves how working with them gives undergraduate students valuable lab experience in microbiological processes.

“I’m a teacher at heart, so I want to see these students take what we can teach them, build those skills and succeed,” Hochman said. “I love my job. I always have.”