It’s not just Vibrio that have displayed this ability to hide from testers – Dr Wagley told New Food that this behaviour was observed in almost 80 other species of bacteria, including Salmonella and E.coli. But if you’re only picking up what can grow, and you’re not picking up things that are in a state of dormancy, you may be missing the whole picture of what and how much is in that sample’s microbial content.” “If you’ve got a food sample, normally what you’ll do is look for the microbial contamination by plating out the contents onto an agar plate. When they’re in the state of dormancy, we can’t get them to grow on these agar plates. She continued: “When Vibrio bacteria are healthy, they grow on agar plates and that’s how microbiologists can detect they are present in a sample. They lose a lot of their identifiable features such as their flagella, so when we look under the microscope, they look very different to what we would normally expect them to look like.” Normally, Vibrio bacteria are rod shaped and small in size, but when they hibernate, they change to a rounder form and they enlarge. “They’re harder to detect because they’ve changed shape from what we have come to believe they look like. Vibrio bacteria are being found more often in UK waters as sea temperatures rise This dormancy can present a problem to the seafood industry, as it makes Vibrio bacteria harder to spot during routine testing. “They hibernate, or go dormant, to protect themselves from those harsh winter conditions,” she clarified. However, Dr Wagley has been examining the bacteria more closely and has found that Vibrios can enter a ‘sleep state’.

“The nutrient levels that they need for their support and growth also reduce, and so we’ve always assumed that during the winter these bacteria die.”

Many of those Vibrio bacteria die because it’s too cold for them to survive,” explained Dr Wagley. “Come winter, you can’t find them in the environment. But what happens to Vibrio bacteria in the winter and how do they keep reappearing each summer in our waters? Vibrio bacteria thrive in warmer climates and continue to be a seasonal problem. “If we find a hot spot, we reach out to the sector and explain issues they may face in the coming years if temperatures continue to rise and recommend ways to keep seafood safe from Vibrios.” Lying in wait “It’s a matter of talking to the shellfish industry and continuing to look at our samples to make sure we’re always on top of Vibrios that are growing in our waters,” she confirmed. But in the past 10-15 years, we have started seeing human pathogenic Vibrios in oysters in areas that are seeing rises in temperature.”ĭr Wagley explained that the summer months in particular invited welcoming conditions for Vibrios and with some coastal areas experiencing more drastic heatwaves, collaboration between scientists and the seafood industry was crucial to these investigations.ĭr Wagley’s team is working closely with the Met Office to identify ‘Vibrio hot spots’ in areas experiencing sea surface temperature rises. “We definitely weren’t finding any of these human pathogenic Vibrios. “Maybe 20-25 years ago, if we looked in our UK shellfish, we probably wouldn’t have found that many Vibrios,” said Dr Wagley. However, due to global warming, the bacterial landscape in the UK is changing, turning it into an ideal Vibrio breeding ground. Vibrio bacteria grow in warm seawater, which means they’re commonplace in areas like New Zealand and Southeast Asia. What are Vibrio and why are they a problem?

Vibrio bacteria shape