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salmonella.org FAQ


We are often asked questions about Salmonella infections. Please read our disclaimer before asking us a question. Specifically, we are not medical doctors we can not offer medical advice. However, we do try and help. Below are some of the FAQs that we have been asked, along with our answers.


Questions and answers

  • Question 1 I am in the process of gathering data regarding Salmonella and was wondering if you could give me some information or where to look at on the issues of Salmonella in relation to completeing a PEST analysis on the subject.
  • Question 2 I am wondering if it is possible for a chicken that is infected with Salmonella to lay eggs that are Salmonella-free? Or, If the Salmonella is on the outside of the egg, and not within the egg.
  • Question 3 My name is Ryan, and I am in 7th grade. For my biology class, I have to do a project on Salmonella. and one of the questions I have to answer about Salmonella growth. I have tried and tried to find out what kind of conditions encourage Salmonella growth, but cannot find any resources to answer this question specifically. It seems like certain temperatures, and perhaps a lack of oxygen stimulate growth, but I really haven_t found that directly_all I can find are articles explaining how to PREVENT growth. Can you tell me anything more about how these types of bacteria grow??
  • Question 4 The BBC news reported a Salmonella virus outbreak.
  • Question 5 I want to ask you a question if I may. How long can I hold water in a tank without getting risk of Salmonella. Considdering that the temperature lies between 20 and 30 degrees Celsius. Can you give me a safe and a risk rate? Like at least 10 days maximum 15 days.
  • Question 6 I have a 2yr old and recently purchased a pekin duck on wed from a farm that kept them separate from other livestock other than other baby duck breeds then I was warned about salmonilla and young children. how do the ducks get sal. is it likely to have it. can the duck be tested?
  • Question 7 I am doing a project on Salmonella and I was wondering if there are any positives with Salmonella like using the virus as a cure for another disease
  • Question 8 I know it is possible for a young child or an elderly person to die from getting samonella. Can an adult or teen die from it, too?
  • Question 9 Just out of curiousity, my wife and I were talking about this.  Chicken eggs, is there more likely hood that Salmonella will be in the yolk or the whites or both?  We got on the subject after she made a cake mix with eggs and our son wanted to lick the spoon, which by the way he didn't!  Thanks for the info.
  • Question 10 I'm researching a diet for dogs that feeds Raw Chicken backs and necks. My biggest concern was the Samonella, yet I'm being told that Salmonella doesn't affect dogs in a negative way. Is there any place that you know of where I could research this more in-depth. Also, I what is the most effective cleaning agent to kill the bacteria on my counters. I've been using hot soapy water with a splash of bleach. Will this be sufficient to keep the kitchen sterile?.....
  • Question 11 Can you get Salmonella from kosher chicken?
  • Question 12 Can Salmonella Tennessee contaminate coconuts?
  • Question 13 I have been adding egg whites to my protein shakes. I am concerned that since they are raw I may get ill. Are my shakes a danger to me?
  • Question 14 My otherwise healthy and active teenage niece had what we believed was a case of Salmonella over a year ago - but has never really felt like she was herself since the illness. This morning she was admitted to the hospital with vomiting and diarrhea and a very high white blood cell count. Should we be concentrating on the Salmonella - does it hang out that long - are there long term consequences
  • Question 15 I have an inquiry about eating blood from poultry, blood in gravy. Is it harmful?
  • Question 16 How do you kill Salmonella in solutions and decontaminate glassware?
  • Question 17 If you take out a chicken breast from the freezer and defrost it. Can you put it back in the refrigerator? Also, if you marinate the chicken and put it in the refridgerator will Salmonella grow?
  • Question 18 Leaving chicken soup out after cooking it.
  • Question 19 Salmonella and fish
  • Question 20 Salmonella and turtles
  • Question 21 Salmonella and ferrets
  • Question 22 Salmonella and eggs
  • Question 23 Survival of Salmonella at room temperature
  • Question 24 Sewer gas and Salmonella
  • Question 25 Identification of Salmonella
  • Question 26 Does freezing kill Salmonella? (1)
  • Question 27 Does freezing kill Salmonella? (2)
  • Question 28 Why do you defrost chickens?
  • Question 29 Detecting Salmonella in lakes.
  • Question 30Cleaning Chicken

Q: I am in the process of gathering data regarding Salmonella and was wondering if you could give me some information or where to look at on the issues of Salmonella in relation to completeing a PEST analysis on the subject.

    A: I am sorry, but I don't know what a PEST analysis is. [Ed note: This page describes PEST analysis]

    I presume that you want information about the infectivity of Salmonella. and I would suggest that you try the CDC website (http://www.cdc.gov/). This is, of course, very American-centric, but I expect the NIH, BBSRC, MRC, or one of those councils in England has a similar site where you can get information related to Salmonella infections. [Ed note: the question was from England]

    The virulence of Salmonella in humans depends on the isolate that you are using - some Salmonella only infect cattle or swine, while others infect only humans. Salmonella Typhi, which causes typhoid fever, is very nasty for humans.


Q: I am wondering if it is possible for a chicken that is infected with Salmonella to lay eggs that are Salmonella-free? Or, If the Salmonella is on the outside of the egg, and not within the egg.

    A: Yes this is possible. In fact, most eggs will be Salmonella free. Some people have estimated that only 1 in 1000 eggs (or less) will be contaminated with Salmonella. however it varies by chicken, Salmonella type, and lots of other factors that we don't understand.

    In general, most of the Salmonella are on the outside of the egg, but one type of Salmonella (Salmonella enterica servoar Enteritidis, aka Salmonella enteritidis) is especially good at getting inside the egg and waiting there. This is why eggs should be stored in the refigerator, it slows down the degredation of the egg and growth of the bacteria


Q: My name is Ryan, and I am in 7th grade. For my biology class, I have to do a project on Salmonella. and one of the questions I have to answer about Salmonella growth. I have tried and tried to find out what kind of conditions encourage Salmonella growth, but cannot find any resources to answer this question specifically. It seems like certain temperatures, and perhaps a lack of oxygen stimulate growth, but I really haven_t found that directly_all I can find are articles explaining how to PREVENT growth. Can you tell me anything more about how these types of bacteria grow??

    A: Most of the work figuring out how Salmonella and similar bacteria (like E. coli) grow is very old. People tried to guess what it would be like in the intestines, where they knew that Salmonella grew, and copied that. They tested different temperatures and found that 37 celsius (98 F) works the best. This is also the temperature of our bodies! Also, they tried lots of combinations of nutrients, and found that Salmonella like to grow with a carbon (sugar) source. Glucose is the best source, just as it is for us. It is high in energy, and so the bacteria can grow quickly. Amino acids, the building blocks that make up proteins, also help the bacteria to grow, but if they are not present, they can make their own amino acids. Finally, most bacteria like a few minerals and ions to be in the media. They need these to help the proteins work and grow, and to make more DNA (the genetic material that is copied each time the cell divides). So most people add some magnesium, phosphorus and few other things.

    In fact, in the laboratory, we usually use a very complex mixture that contains three things:

    1. yeast extract: this is like the yeast that is used to make bread and beer, but we kill the yeast, and then the bacteria can grow on them. The yeast extract contains lots of nutrients and goodies for the bacteria to eat.
    2. tryptone: this is a broken down form of casein, proteins that are found in milk. This supplies the bacteria with some amino acids that are not present in the yeast extract.
    3. NaCl: this is table salt. We use this because the Salmonella like a salt rich environment (like the intestine is) but other bacteria don't like it and won't grow so well.

      If we put Salmonella in this mixture, and warm them at 98F, they divide about once every 20 minutes!

      We can also grow Salmonella in a defined media that contains magnesium, iron, and phosphorus, along with some nitrogen (we usually use ammonia because they like this) and glucose. In this case they grow a bit slower because they have to make all their own amino acids.

      Salmonella like to have oxygen, but they don't need very much of it. In fact, if there is none around, they can still grow but they do it much slower.

      Also, Salmonella don't grow very well in colder places. That is why it is important to keep things that Salmonella like to grow on (like raw chickens and eggs) in the fridge. This slows them down so that you are much more likely to kill them all when you cook the chicken.

      Good luck with your assignment.


Q: The BBC news reported a Salmonella virus outbreak.

    Your press on the "virus hit hospital" in Scotland may be confusing to many people because "Salmonella" and "virus" are used without distinction. My interpretation of your reports is that there must be a concurrent outbreak of Salmonella and some type of virus.

    As I am sure your reporters know, Salmonella is type of bacteria, not a virus. This is not a trivial difference, because bacteria like Salmonella can be treated with antibiotics while viruses cannot. Furthermore, Salmonella is not airborne while a concurrent viral outbreak might well involve a virus transmitted via aerosols.

    It is essential to describe these infectious diseases properly to avoid causing undue public fear or to encourage improper self-treatment which may facilitate the spread of antibiotic resistance.


Q: I want to ask you a question if I may. How long can I hold water in a tank without getting risk of Salmonella. Considdering that the temperature lies between 20 and 30 degrees Celsius. Can you give me a safe and a risk rate? Like at least 10 days maximum 15 days.

    A: The risk strictly depends upon contamination. Salmonella contamination is acquired from animal/bird/reptile/human feces, so if the tanks are not exposed to such sources of contamination, it should be OK from a Salmonella perspective. If it is exposed to such contamination, it is unsafe no matter how long is has been stored. Note that Salmonella is not the only potential bio-contaminant in water.


Q: I have a 2yr old and recently purchased a pekin duck on wed from a farm that kept them separate from other livestock other than other baby duck breeds then I was warned about salmonilla and young children. how do the ducks get sal. is it likely to have it. can the duck be tested?

    A: Fowl can be carriers of Salmonella. although the probability is relatively low (in fact, probably lower than the likelihood of contacting Salmonella from common food sources). Because shedding of the bacteria from an asymptomatic carrier can be sporadic, it may be difficult to detect Salmonella in the pet duck. Although this is somewhat difficult to control with a two-year old, avoiding oral ingestion of the water or feces possibly contaminated by the duck, and careful handwashing after contacting the duck will effectively decrease the potential for contacting a Salmonella infection. Nevertheless, there is no absolute guarantee.


Q: I am doing a project on Salmonella and I was wondering if there are any positives with Salmonella like using the virus as a cure for another disease

    A: First, Salmonella are a bacteria and not a virus. This is a very important distinction, because bacteria can be treated with antibiotics, but they do not work with viruses. That is why when you get a cold (usually a virus) the doctor may not give you antibiotics.

    There is not a lot of work on using Salmonella to cure other diseases, although there is a report that Salmonella can be used to treat cancer. This is very preliminary work, and scientists are still studying it to find out how to make the system better and develop a potential cure. It is a long way off though.


Q: I know it is possible for a young child or an elderly person to die from getting samonella. Can an adult or teen die from it, too?

    A: First let me begin by saying that I am not a physician. If you know of someone who is ill, you should promptly see a physician.

    Adults or teens can die from a Salmonella infection. Although this is rare in otherwise healthy individuals, Salmonella can be lethal for people who are immunocompromised (have a weakened immunity) due to another illness or medical treatment (e.g. due to cancer chemotherapy or due to treatments following organ transplantation). It is also possible that if a person is treated with an inappropriate antibiotic (an antibiotic that the Salmonella is resistant to but which kills other bacteria that normally live in the intestines of healthy people), the illness will be much more severe and possibly lethal.

    Most healthy adults and teens infected with types of Salmonella that are common in the US will be quite sick for several days, then recover without antibiotic treatment. Many physicians and scientists believe that unless there are other factors (e.g. immunocompromised or an exceptionally long illness) that it is best to avoid antibiotic treatment.


Q: Just out of curiousity, my wife and I were talking about this.  Chicken eggs, is there more likely hood that Salmonella will be in the yolk or the whites or both?  We got on the subject after she made a cake mix with eggs and our son wanted to lick the spoon, which by the way he didn't!  Thanks for the info.

    A: When present, Salmonella is initially in the "whites" of fresh eggs. However, this environment is restricted for some nutrients that Salmonella needs so the bacteria are usually present in low numbers. As eggs age the membrane around the yolk sac begins to break down and releases nutrients that Salmonella needs to grow, so the bacteria can move toward the yolk (by a process called chemotaxis) and reproduce.


Q: I'm researching a diet for dogs that feeds Raw Chicken backs and necks. My biggest concern was the Samonella, yet I'm being told that Salmonella doesn't affect dogs in a negative way. Is there any place that you know of where I could research this more in-depth. Also, I what is the most effective cleaning agent to kill the bacteria on my counters. I've been using hot soapy water with a splash of bleach. Will this be sufficient to keep the kitchen sterile?.....

Thank you so much for your time.

    A: It is not clear that Salmonella does not affect dogs in a negative way. Most dogs do not get serious Salmonella infections, but that is probably because they do not usually get large doses of infected food/water as might occur if fed raw chicken. Furthermore, dogs can be carriers of Salmonella. so infected dogs can be a serious risk for human health. (Also note that raw chicken may lead to Campylobacter infections as well as Salmonella infections.)

    There is ample epidemological evidence that dog feces may be an important source of environmental contamination, and spread of Salmonella to humans (try a search of PubMed for the keywords Salmonella AND dog). One reference directly related to inclusion of raw chicken in dogfood is:

    Can Vet J 2002 Jun;43(6):441-2 Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets. Joffe DJ, Schlesinger DP.

    Also note the following reference that mentions the incidence of disease in dogs:

    Vaccine 2002 Feb 22;20(11-12):1618-23 Immunogenicity of chi4127 phoP- Salmonella enterica serovar Typhimurium in dogs. McVey DS, Chengappa MM, Mosier DE, Stone GG, Oberst RD, Sylte MJ, Gabbert NM, Kelly-Aehle SM, Curtiss R. "Salmonellae are commonly isolated from dogs. The number of dogs infected with Salmonella spp. is surprisingly high and greater than the incidence of clinical disease would suggest. Salmonellosis is common in greyhound kennels. Morbidity can approach 100% in puppies and the mortality ranges to nearly 40%."

    Bleach is an effective disinfectant of the countertop, but it is essential that the area is thoroughly cleaned because the bleach may not effectively penetrate any dried residue.


Q: Can you get Salmonella from kosher chicken?


Q: I happened to see your website talking about Salmonella and I wonder if you could tell me something about Salmonella Tennessee. I would like to know about its origin and its characteristic. Is it possible this bacteria can be found from the coconut products. I have a buyer is suspecting that my product is contaminated with Salmonella Tennessee but as far as I know the Salmonella bacteria can be detected from the coconut product is called Salmonella Seftenberg but not the Tennessee! Hope you could provide me the detailed information about the Salmonella Tennessee especially about its origin and characteristic! Your assistance will be of great help to me!

    A: I do not specifically know about Salmonella serotype Tennessee, however it is possible that if one serotype (Seftenberg) can be isolated from coconut products another could also.

    There have been a few confirmed illnesses with Salmonella serotype Tennessee, for example (http://vm.cfsan.fda.gov/~mow/saltenn.html), therefore I suggest that you employ the services of a diagnostic laboratory that will be able to test whether your product is contaminated with Salmonella.


Q: Hope you can answer my question, I have been adding egg whites to my protein shakes. I am concerned that since they are raw I may get ill. Are my shakes a danger to me? Thanks for your time!

    A: Raw eggs can contain Salmonella. The probability depends on where your eggs come from, how fresh your eggs are, and other factors. You can get lucky for quite awhile, but you are taking a chance with raw eggs. It is possible to buy pasteurized or irradiated eggs that are "Salmonella-free".


Q: My otherwise healthy and active teenage niece had what we believed was a case of Salmonella over a year ago - but has never really felt like she was herself since the illness. This morning she was admitted to the hospital with vomiting and diarrhea and a very high white blood cell count.

Should we be concentrating on the Salmonella - does it hang out that long - are there long term consequences

    A: I am not a physician, so I am not competent to give medical advice. However, I'd make sure she is seen by a good infectious disease specialist. I know how worrisome this must be ... sorry I couldn't help.


Q: I have an inquiry about eating blood from poultry, blood in gravy. Is it harmful?

    A: If the gravy is boiled the Salmonella and other bacteria that may be in the blood will be killed. If the juices from the cooked poultry are +used, as long as the poultry is thoroughly cooked the bacteria will also be killed.


Q: I just move to a new lab in Hospital For Sick Children, the PI is studying about Salmonella. I wonder how to treat Salmonella waste which growed in flask after I am done my experiment. The PI suggest I do autoclave first, then throw away the liquid , at last , washing and autoclaving the flask. but the cleaning lady said she never did that.she said we shoud treat pathogen by ourself. Except the PI's way, do you think I can use some other ways to treat pathogens, eg, use 10% bleach to treat the pathogen solution or if there is any special solution I can use, and which company I can get it.Thank you very much.

    A: Bleach will effectively kill Salmonella. but it demands prolonged exposure (also true for other decontamination solutions available). Bleach is a good way to decontaminate solid surfaces, for example if some solution is spilled.

    The best way to treat solutions (or contaminated petrie dishes, paper bench covers, set) is by autoclaving. After autoclaving the solutions can be poured down the sink and flasks, etc can be simply washed in an automatic dishwasher or by hand. The only caveat is that the autoclaving must be sufficiently long to fully sterilize the solutions (which depends upon the volume of the solutions).


Q: I am a year 16 old student and while cooking the other night, got into a debate about the growth of Salmonella with another family member. I was wondering if you could help us. If you take out a chicken breast from the freezer and defrost it. Can you put it back in the refridgerator? I said no. Also, if you marinate the chicken and put it in the refridgerator will Salmonella grow? If you could take the time to answer my question i'd appreciate it very much. Thankyou.

    A:You are correct. Once defrosted Salmonella can grow on the chicken and continue to grow until it is completely frozen again -- upon re-defrosting that Salmonella will begin with a larger starting population and resulting in a larger final population.

    There usually isn't a problem if the chicken is marinated for a limited time in the refrigerator (kept at 4 C, not at room temperature), then cooked immediately. However, this could depend upon the marinade, the time in the refrigerator, and the number of bacteria associated with the chicken prior to use.


Q: I have a question for you, if you have the time. My family had been sick so I made a huge pot of homemade chicken noodle soup for us to eat. My husband came home from work late and took it off the burner and put it on another ate his dinner and forgot to put it in the fridge it sat out for nearly 10 hours at room temp. I had contacted the me local Health Dept. and they said throw it out there is too big of a risk that it could have grown Salmonella or another form of bacteria, so we did. But I am just curious to know what time frame can food like that sit at room temp. I usually let it cool down for about an hour before putting in the fridge, should I not do that and immediately put it in there from the stove. If you could give me an idea I would appreciate this. Thank you!

    A: There is not a simple answer to this question because it depends upon the inoculum of microbes (they have to be present in the food or from human contamination), the composition of the food, etc. It takes time for the bacteria to reproduce in the food. The longer the food sits at room temperature the more likely there is to be a problem (overnight is way too long). In particular, when warm food slowly cools to room temperature, the bacteria can grow quite quickly at the intermediate temperatures. It is unlikely that if the food is allowed to cool sufficiently to be placed in the refrigerator (that is, it is no longer hot, but still warm) that there will be a problem. Sorry there is not a straightforward, simple answer, but I hope this helps.


Q: Sorry to interupt your day with the question, but does Salmonella exist in fish? I can understand through cross contamination when prepairing fish, but does it exist in the way that it might cause an infection in a human by eating fish?

    A: Salmonella has been isolated from fish. It is not clear to me whether the source is via the human handlers or via the fish per se. Human outbreaks from fish seem to be rare, but I recall that several years ago there was an outbreak due to smoked eel consumption in Germany.


Q: I have 2 turtles. I don't know if they are male or female. They have said to have very bad Salmonella. They are about 6 yrs old now. When ever I clean their tank, sometimes, there is a lot of dirt and grime built up. Isometimesuse bleach to clean their rocks. I make sure that I wash it out very good before putting them back in their. Am I doing anything wrong in that matter? I would also like to know how I can get sick from Salmonella from these turtles. I always thought that the only way I could get sick was from touching their water or them with a cut on my finger or by not washing my hands and then touching my food. Is this true? There is one more thing. If I spill some of their dirty water on the carpet, and it dries can I still get sick? And one more thing. Thank you for your time and have a nice day.


Q: I wanted to know if ferrets carry Salmonella. The reason I ask is because my sister's husband have one and my 5 year old had Salmonella when she was 2-3 months old and I don't know that if I take her over there that I'm taking a risk of my daughter getting it again or my other 2 kids. Thank you for your time.

    A: There are reports that ferrets can be infected with Salmonella. but I know of no documented cases where they have been shown to act as carriers. From reports I am aware of, ferrets seem quite sensitive to Salmonella showing gastrointestinal symptoms like those of humans. Nevertheless, it is probable that a low percentage of any susceptible animals will become carriers following an overt infection.


Q: It seems that, based on other FAQs, there is a chance of getting Salmonella from raw eggs, so how concerned should I be about licking the spoon after mixing chocolate chip cookies? Also, should I be concerned about Salmonella in Chocolate Chip Cookie Dough Ice Cream, or does the fact that this dough is frozen perhaps alleviate the concern for contracting Salmonella in this case?

    A: The eggs are now pasteurized before use in commercial ice cream (including componants of ice cream like cookie dough). Freezing can decrease the number of viable Salmonella. but other components like milk protein, etc can protect the Salmonella. so this is not an effective way of decontamination. The risk from raw eggs varies greatly depending upon the number of eggs used, the part of the country you are from, and other factors. There have been cases of Salmonellosis attributed to foods made with raw eggs, including key lime pie, mayonnaise, caesar salad, andlicking utensils from uncooked foods. The risk of acquiring Salmonellosis from licking a spoon may be small, but there is indeed some risk if raw (unpasteurized or unirradiated) eggs are used.


Q: If I have a raw egg that is known to be contaminated with the Salmonella bacteria and I crack it onto my kitchen counter (for example) and leave it there to dry (at room temperature), how many hours/days will it take until the bacteria is no longer harmful to humans if it was touched by a hand or by another piece of food and then consumed by the person?

    A: Although it seems trivial, that is not a easy question to answer because survival depends upon conditions like humidity, etc, and infection depends upon susceptibility and dose of the bacteria consumed. However, when surrounded by proteins from the egg, it is clear that Salmonella can survive for weeks or months. Therefore, it is a good idea to clean your counters thoroughly. Salmonella is quite sensitive to mild disinfectants, including simple things like a dilute bleach solution.

    One more point ... although some eggs may contain Salmonella so this is a real food safety issue, the presence of Salmonella in eggs remains quite low in most parts of the country at most times because of careful surveillance. The biggest problem is when lots of eggs are combined, like when making an omelette for a very large group of people.


Q: Given that Salmonella lives in feces, can proximity to sewage produce infection? Can Salmonella be aerosolized by sewer gas? Would pouring Clorox down the drain once a week and covering it with a flat, plastic stopper prevent infection if the pipe was a source?

    A: It is extremely unlikely that you acquired Salmonella from an aerosol from the drain. Although there are reports of Salmonella infection via aerosol, these cases all involve very high concentrations of Salmonella in a laboratory setting known to produce aerosols. (The drain pipe situation is common in many buildings with open overflow drains, often resulting from evaporation of fluid from the sewage trap. Simply pouring water down the drain is usually enough to prevent the odor, but bleach would work also.) It is more likely that you acquired the Salmonella from water or food. In particular, lettuce is often a culprit because it is easily contaminated and each leaf must be individually scrubbed to remove surface bacteria. I have spent a lot of time in in parts of the world where Salmonella is an endemic problem, and I know that it is sometimes difficult to provide completely avoid Salmonella even in the very best and cleanest establishments. I hope this helps.


Q: I am wondering if you can help me to identify what diseases would produce a positive blood culture for Salmonella O Type Vi. I think it may be typhoid fever, but I went through your website and wasn't able to confirm with certainty. Also what is Salmonella H Type B? Thank you.

    A: For advice on diagnosis, we recommend that you contact your local county/state/regional public health laboratory or the CDC. You might begin by an online search for Salmonella and Pulsenet


Q: Sorry to bother you, but I have read and read and still don't know if freezing will kill Salmonella. Lots of advice about defrosting etc., but is this to prevent contamination from other sources, or is the Salmonella present when thawed?

    A: Salmonella is notcompletely killed by freezing, especially when present in food. Freezing is NOT an effective way of decontamination. The Salmonella that survive freezing can grow during defrosting at elevated temperatures (above refrigerator temperature).


Q: I need to determine whether freezing raw eggs whites and/ or yolks in homemade ice cream will kill any Salmonella present - is it time dependent at O degrees F? I'd like to reaasure parents vs. rejecting most recipes when kids will be present. Thanks.

    A: Freezing is NOT an effective way of killing Salmonella. Although Salmonella is sensitive to freezing in water, the protein in the ice cream protects the Salmonella. There have been documented cases of Salmonella infections from raw eggs in frozen ice cream. If you are dealing with the public, particularly sensitive populations like children, you should avoid uncooked eggs unless they are irradiated or "Pasteurized".


Q: Can you tell me why we shouldn't cook chicken taken directly from the freezer, without defrosting it first. What are the dangers, if there are any? Would they be the same for beef? I know some fast food restaurants cook their burgers directly [from] frozen.

    A: There is no a health reason for not defrosting. Rather, it is difficult to cook the meet thoroughly when it begins frozen. Fast food restaurants uses very thin patties to avoid this problem.


Q: This summer i'm going on a camp with some little children and there is a lake in that area but the chance on Salmonella in that lake is quite big. Can I detect Salmonella in that water by some kit? It may be a smal test with chemicals to because I've studied chemistry.

    A: There is not a simple, over the counter test for Salmonella that would be useful. Most places have requirements for "coliform counts" (indicating all types of bacteria that indicate sewage/fecal contamination) to be below a certain level considered safe by public health standards for use of public lakes, etc, however this criteria will not apply to farm ponds, etc.

    In fact, a microscope is not an appropriate test for Salmonella. Every environment has many bacteria that are not harmful, and many have the same size and shape as Salmonella under the microscope. Identifying Salmonella would require culturing the bacteria on special media, tests with specific antibodies, or assaying for Salmonella specific DNA -- i.e. reasonably complex unless you are trained in microbiology and have the appropriate equipment. Moreover, it is even more difficult with a lake because the bacteria may be quite dilute.


Q: How should chicken from the supermarket (e.g. Perdue) be cleaned prior to cooking? My wife learned from her mother to clean it with salt to help remove Salmonella. Does this work?

Also, after cleaning the chicken over the sink, how should the sink where the chicken is rinsed be cleaned of any possible Salmonella? Will Ajax powder work?

    A: See this USDA website for proper handling of chicken.

    The best way to clean up after use is with a cleaner that contains an antibacterial agent, like bleach or lysol, but simple soap and water (or Ajax) seems quite effective.


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