GALVESTON, Texas (AP) - Mona Hochman and her lab mates frequently ruin perfectly good oysters. But it’s all in an effort to weed out the bad ones from the market.
Hochman manages Texas A&M University at Galveston’s Seafood Safety Lab where thousands of Gulf oysters are sent each year for sample testing for bacteria that can make consumers sick, or worse.
Oyster processors regularly send samples, usually about 10 oysters, of their products for testing at the lab. The oysters have already gone through some sort of processing, either quick freezing, high pressure treatment or some sort of pasteurization, as they would if they were headed to a market or restaurant.
Oyster processors who use a post-harvest process to reduce bacteria and market product safety to the public are required to have the product tested by a federal Food and Drug Administration-certified lab, Hochman said.
The lab in Galveston is one of just two certified safety labs on the Gulf Coast, making it the prime spot for testing most post-harvest processed oysters in the country.
“We work with the processors basically from southern Texas all the way to Florida and we test almost everybody’s seafood that is doing these post-harvest processes,” Hochman told The Galveston County Daily News (https://bit.ly/2mb6IUA ). “We’re working to maintain the safety of seafood.”
The lab tests for two naturally occurring bacteria: Vibrio vulnificus and Vibrio paraphaemolytious. The former grabbed headlines last year when it was falsely labeled as a flesh-eating bacteria, scientists said.
Vibrio vulnificus can cause gastroenteritis in any healthy person, but it can kill someone who has health problems such as diabetes, cancer, HIV, heart ailments, hepatitis or other liver diseases, Hochman said.
“It’s not a flesh-eating bacteria, I can’t stress that enough … if it was, we’d all be in trouble because we have it in the lab right now,” Hochman said.
But the bacteria can be deadly for people with compromised immune systems and can make otherwise healthy people feel incredibly sick, she said.
Vibrio parahaemolyticus is not deadly, but can cause bad gastroenteritis if consumed through raw or undercooked seafood, she said.
“It won’t kill you, but it will make you wish you were dead,” Hochman said.
The Texas Department of State Health Services tests water quality and oysters in Galveston Bay and elsewhere, and issues advisories or closes parts of the bay if too much bacteria is found, Hochman said.
The university’s lab is the only one in the state testing premarket oysters.
Properly cooking seafood kills bacteria and bacteria is rare during winter months when water temperatures drop, she said.
“The problem comes when people either eat undercooked seafood or raw oysters - people love raw oysters, that’s why we typically just deal with testing oysters,” Hochman said.
With the exception of individual quick freezing, the post-harvest processes are supposed to instantly kill the bacteria, Hochman said, but the methods aren’t foolproof.
Once the shipped oysters arrive, researchers first take the temperature of the water they are sent in. The colder the temperature, the lower the bacteria level, she said. The oysters are then shucked and blended.
“It makes an oyster smoothie, which we then put into test tubes,” Hochman said.
Researchers grow both types of bacteria to be used as a control, she said. The oyster samples are smeared in a petri dish, which is cross-tested with the control sample.
“We can tell by the color and way the colonies look if we are looking at those types of bacteria,” Hochman said.
“If you’re just taking oysters out of the bay, you might come across the bacteria, but those that have been post-harvest processed, you should not have bacteria.”
The number of bacteria is reported for each sample, she said. The federal Food and Drug Administration allows marketable oysters to have up to 30 bacteria per gram, but many processors operate on stricter guidelines, accepting maybe three bacteria per gram instead, she said.
Hochman can’t remember the last time a sample had higher than the allowable number.
“It’s exceptionally rare,” she said. “If it were to happen we would immediately contact the processor, they would look into the process and we would do a retest.”
“It’s a heavily monitored chain of reactions … It’s a huge paper trail.”
At any given time, the lab has about six researchers testing the thousands of oysters that come through each year, two full-time in the lab and six to seven paid student workers.
The opportunity is rare and immeasurably beneficial because there are just two labs on the Gulf Coast, said Alejandra Jacquez, a senior at the university studying marine biology. Working in the lab provides more insight into how one of the Gulf’s most popular seafood items gets to market, she said.
“When you go to a restaurant and have seafood you don’t think about all the people behind the curtains,” Jacquez said. “We’re the people behind the curtains and it’s interesting to learn about that side of it.”
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Information from: The Galveston County Daily News, https://www.galvnews.com
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