Munching on fresh cantaloupe this morning made me check in on the status of the Salmonella Litchfield outbreak that has sickened 50 across the United States over the last months.  Unfortunately, outbreaks tied to cantaloupe have been a far to frequent occurrence. There have been several articles on what consumers can and can not do to protect themselves. I wondered what growers and shippers might be doing. I found this interesting article and great pictures – from 2005. Guess we need to do a bit more?

Scientists Aim for Cleaner Cantaloupe

Simply washing fresh fruits and vegetables may only be marginally effective at removing microbial contaminants, so scientists are investigating new techniques for better processing produce.

Bacteria quickly attach to the surface of fruits and vegetables and form biofilms, a mass of microbes that attach to a surface and to each other by complex sugars. Scientists believe that biofilm coatings may protect bacterial cells from exposure to antimicrobial compounds used to sanitize produce.

Salmonella bacteria are often responsible for produce-related outbreaks of foodborne illness. They’re especially tricky to remove from cantaloupe because they attach to inaccessible sites and form biolfim on cantaloupe rind surface, allowing the bacteria to avoid contact with sanitizing solutions. Surviving Salmonella cells can be transferred from the surface of the melon to the internal tissues during cutting prior to consumption.

Now, researchers at the USDA’s Agricultural Research Service have gained new insight into Salmonella biofilm formation on various surfaces. They have discovered that to form on plastic or stainless steel, the bacteria must produce hair-like structures–called fimbriae–and cellulose to help the cells to attach and colonize the surface.

In cantaloupe, Salmonella cells attach to the rind and rapidly begin developing biofilm by growing and excreting sugars. This discovery helps explain how Salmonella survives harsh sanitizing environments and could help lead to better sanitization techniques.

  • I live in California and I’ve been trying to stay away from Cantaloupe since I heard about the outbreak. One of my coworkers thinks he got sick from a contaminated cantaloupe about a week ago. Its just frightening to think that washing our fruits and veggies like my parents used to do (and I do for my kids) isn’t cutting it anymore.

  • A. Franklin

    While researching cantaloupe-associated foodborne illness outbreaks, I came across this site. As a former registered environmental health specialist, I often performed foodborne illness investigations and remember the initial E. coli O157:H7 oubreaks very well. Thank you for educating the public and representing plaintiffs affected by foodborne illnesses. Your work raises awareness of the dangers inherent in our food supply and has saved more than a few lives.
    As a personal note, I have family and friends who almost died or suffered miscarriages from E. coli O157:H7 and antibiotic-resistant salmonella infections. Years ago, I prevented an abusive emergency room physician from forcibly arranging an appendectomy on me by insisting that the hospital perform a stool sample culture for B. cereus prior to the surgery. He refused and even assaulted me during the physical examination. Thankfully, I was able to convince other staff and administration to intervene and the physician lost his ER privileges. The culture was positive for B. cereus and I avoided an unnecessary surgery. This experience was rather atypical but too many physicians fail to respond to foodborne illnesses in a timely or appropriate manner.
    However, I must disagree with your post on “INS Raids, Bad for Consumers?”. When I first inspected migrant housing as part of my environmental health training, I was amazed at the minimal level of sanitation standards required by my state for housing agricultural workers. While waiting in a long line for a prophylactic gamma globulin injection during a Hepatitis A outbreak, I pondered the connection between contaminated strawberries and the lack of field worker access to potable water, soap, or clean toilet facilities. Due to a number of factors, disease surveillance is very difficult to perform in populations that are often very transient and reluctant to be identified due to their immigration status. Illegal immigration profoundly compromises the ability of our current federal and state systems to protect the public health. When I was still a sanitarian, I predicted a rapid increase in the incidence of preventable communicable diseases based on patterns that I observed while conducting “shoe leather epidemiology”. A few years later during my second week in law school, I woke up paralyzed following an undiagnosed bout of atypical measles encephalitis.
    For two years I underwent several tests to pinpoint the nature of my severe and persistent symptoms. While reviewing my medical records I noted that my first physician performed an IgG titer for rubeola but not a second IgM titer to confirm the extremely high first titer result. When asked, she stated she ran the titer because there was an ongoing measles outbreak in our county when I first presented with symptoms. After contacting the state public health lab, I learned that she never reported the outbreak as required by state and federal law. Her reason for not performing the blood work for my second titer? She would have been required to report the other measles cases and chose not to identify the other patients due to the risk that they would be deported based on their undocumented status. After almost ten years, I am finally reapplying to law school to complete my JD. How many other physicians intentially under-report deadly disease outbreaks?
    Immigration reform must address the public health consequences of illegal immigration while also recognizing the need for social justice. Americans ARE willing to perform the often dangerous and low-paid tasks associated with food production and processing. My family members who worked at the former Imperial Foods plant in Hamlet, North Carolina can attest to this premise. My friends who toil in Iowa packing houses would also agree with my assessment. The public health component to immigration policy existed long before Ellis Island was ever built. Unfortunately, like the quarantine buildings at a certain national monument, the surveillance and reporting systems in this county are crumbling. Until all interested parties address the implications of immigration and other aspects of globalization on food safety, foodborne illnesses and intoxications will continue to escalate.

  • jknowles

    If surveillance of procedures, sanitation and access to proper cleansing, namely soap and water, is so difficult for migrant/immigrant workers to come by; why isn’t it required that they use latex gloves to prevent foodborne illness infection?
    Perhaps there is something about harvesting and the use of there kind of gloves that I do not understand.
    Someone, please advise. Thank you.