What Types Of Bacteria Live On Your Fruits And Vegies?

New research has confirmed fresh fruit and vegetables carry an abundance of non-pathogenic bacteria on their surfaces; and certain organic fruits are among the worst offenders. The family of microbes also varies wildly, depending on the type of produce and the cultivation methods used.

Fruit picture from Shutterstock

Researchers at the University of Colorado tested the surface of eleven produce types with a focus on fruits and vegetables that are often consumed raw. The researchers found that distinct bacterial communities and substantial variation in bacterial richness were present across all produce analysed.

We found the surface bacterial communities of spinach, lettuce, and tomatoes to be numerically dominated by Gammaproteobacteria. Similarly, we found the family Sphingomonadaceae within the class Alphaproteobacteria was the most abundant family present on apples.

The report also found differences in surface bacteria between produce grown using different farming practices, with farm locations, storage temperature and transport conditions all playing their part.

"Our results suggest that differences in farming practices could be influencing the relative abundance of specific taxa on the surfaces of fresh produce available at grocery stores," the report states.

Interestingly, the study also found bacteria levels varied greatly between conventional and organic-labeled produce. However, the scales were sometimes tipped in the conventional produce's favour, particularly when it came to grapes and peaches. The researchers put this down to a variety of factors, including growing location, fertilizer use, pesticide use and shipping/handling procedures.

Below is a full table detailing the research team's bacterial findings:

Produce Type OTU classification Relative Abundance (%)
Sprouts (bean) Pantoea sp.

 

Klebsiella/Raoultella sp.

57.5

 

14.4

Spinach Pantoea sp.

 

Klebsiella/Raoultella sp.

32.4

 

9.0

Lettuce Xanthomonas sp.

 

Pantoea sp.

 

Pectobacterium sp.

 

Leuconostoc sp.

 

Janthinobacterium sp.

10.0

 

8.9

 

8.0

 

6.9

 

5.7

Tomato Klebsiella/Raoultella

 

Pectobacterium sp.

26.9

 

9.8

Sprouts (alfalfa) Acinetobacter sp. 9.3
Strawberries Buchnera aphidicola

 

Bacillus sp. 1

 

Pantoea sp.

23.6

 

17.1

 

10.4

 

Apple Photobacterium sp. 5.6
Peach Microbacterium sp.

 

Undetermined microbacteriaceae

6.2

 

6.1

 

Grapes Bacillus sp. 1

 

Gluconacetobacter sp

 

Bacillus sp. 2

18.2

 

6.0

 

5.0

 

Pepper Pantoea sp. 11.1
Mushrooms Pseudomonas sp.

 

Pedobacter sp.

11.3

 

5.5

 

Although none of the above microbes cause disease directly, they can impact the rate at which food spoils and may also play a role in the spread of harmful microbes in the kitchen.

In other words, it's probably a good idea to thoroughly wash your fruit rather than giving it a trusty shirt rub.

Bacterial Communities Associated with the Surfaces of Fresh Fruits and Vegetables [PLOS ONE]


Comments

    Actually, the amount of Bacteria or Pathogens on my fruit and veg doesn't bother me so much as wondering if someone just picked their nose, scratched their itchy chocolate star fish or sneezed all over the place! I always wash my produce first.

    Vectors like people and flies concern me as well, but potential pesticides more so.

    What a breakthrough! Less bugs on food sprayed with pesticides? Who would have thought... And less bugs on food that isn't sprayed with poison?

    Definitely new research.

    "Although none of the above microbes cause disease directly, they can impact the rate at which food spoils and may also play a role in the spread of harmful microbes in the kitchen.

    In other words, it’s probably a good idea to thoroughly wash your fruit rather than giving it a trusty shirt rub."

    So you're worried the food will spoil in your stomach whilst you're digesting it?

    Chris, will you be doing a follow-up article on what type of bacteria lives in various human body parts you plan to eat, too?

      Why do you eat human body parts?

        Chris does, if his recent article on placenta pizza is anything to go by.

    Stupid question, is water enough to wash the fruit and remove the nasties?

      Nope. And you probably don't want to..given that this may be novel data, its not a novel occurrence....yet somehow we've evolved to survive the "nasties". Some of these are probably good for us when residing in our guts (if they make it that far).

    There are a lot of very cool gizmos, and people who use them, working to understand the bugs (bacteria) that normally colonize our guts....differences between different groups have been looked at and its pretty obvious that our gut microbiome (all the bugs that live in your gut; there is also a term for the viruses, the gut virome) change with age, over time, in response to antibiotics, across space, during disease (say an acute raging gut virus) and with diet. Those changes can be for better health....or worse. Google gets you to some of this info - a lot is in publicly available research articles too. http://en.wikipedia.org/wiki/Gut_flora is a starting point as is http://www.nature.com/nature/focus/humanmicrobiota/.

    Some of the bacterial species that we normally harbour in our guts include....
    Prevotella, Lactobaccillus, Propionibacterium, Streptococcus,
    Soemof the domiant genera (a genus has lot sof species in it) include those harbouring the species above plus..
    Bacteroides, Veillonella, Haemophilus, Moraxella and Staphylococcus.

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