Vibrio cholerae and vibrio parahaemolyticus growth in ready to eat frozen product
Hi Everyone
I am dealing with vibrio growing in our "ready to eat" frozen product, these are south Asian style curries, main ingredient is boneless fish. we cook these curries in open cooking pans at direct stove flame (a conventional style cooking at +80C) and then these curries are filled in plastic air tight boxes, freeze in blast freezer, final product core temperature is -18C.
our microbiological testing results showing growth of two types of vibrio, cholerae and parahaemolyticus, which means the microbe is resistant to cooking and freezing.
if anyone can help me out that what could be the possible reasons for contamination with this organism and what ways can be use to kill this organism.
Looking forward to your responses
80 C+ degrees should kill vibrio. Is there are a chance that it is contaminated after the heat treatment?
There are some fish experts on here, hopefully they will chime in.
Hi Everyone
I am dealing with vibrio growing in our "ready to eat" frozen product, these are south Asian style curries, main ingredient is boneless fish. we cook these curries in open cooking pans at direct stove flame (a conventional style cooking at +80C) and then these curries are filled in plastic air tight boxes, freeze in blast freezer, final product core temperature is -18C.
our microbiological testing results showing growth of two types of vibrio, cholerae and parahaemolyticus, which means the microbe is resistant to cooking and freezing.
if anyone can help me out that what could be the possible reasons for contamination with this organism and what ways can be use to kill this organism.
Looking forward to your responses
Hi Nazia,
IIRC these 2 species are not particularly heat resistant. Problem may be recontamination due hygiene deficiencies.
Do you confirm results for both species via antisera since IMEX identification can be difficult due many competing Vibrio species with similar biochemical profiles ?.
Vibrio species in general are naturally associated with marine fish but the pathogenic varieties more typically via water contamination or local coastal water pollution.
PS - overlapped Post 2. :smile:
Hi Nazia,
Some recent research showing resistance of Vibrio:
Have you been checking levels in your raw fish? and other ingredients? and water supply?
Kind regards,
Tony
Hi Nazia,
The FDA Food Code requires that food be cooled from 57.2°C to 21.1°C (135°F to 70°F) within two hours and from 57.2°C to 5°C (135°F to 41°F) within a total of six hours and defines it a critical control point essential to preventing foodborne illness outbreaks. I am curious if your cooked curries in plastic air tight boxes meet that cooling requirement?
Thanks
Thanks for your reply, the other specie with green color colony is "vulnificus", so can you that what process we can adapt to kill this organism
Hi Nazia,
IIRC these 2 species are not particularly heat resistant. Problem may be recontamination due hygiene deficiencies.
Do you confirm results for both species via antisera since IMEX identification can be difficult due many competing Vibrio species with similar biochemical profiles ?.
Vibrio species in general are naturally associated with marine fish but the pathogenic varieties more typically via water contamination or local coastal water pollution.
PS - overlapped Post 2. :smile:
Hi Nazia,
Some recent research showing resistance of Vibrio:
Have you been checking levels in your raw fish? and other ingredients? and water supply?
Kind regards,
Tony
thanks for your reply. yes we checked other ingredients as well, it is also found in raw fish with green color colonies, which may be "parahaemolyticus" or "vulnificus". I have no idea for control of "vulnificus", so if you can give any suggestion for this. thanks
Hi Nazia,
The FDA Food Code requires that food be cooled from 57.2°C to 21.1°C (135°F to 70°F) within two hours and from 57.2°C to 5°C (135°F to 41°F) within a total of six hours and defines it a critical control point essential to preventing foodborne illness outbreaks. I am curious if your cooked curries in plastic air tight boxes meet that cooling requirement?
Thanks
Thanks for your reply. our cooked curries have temperature of 80C just after cooking, then it cools down to around 50C during filling in air tight plastic boxes and with half an hour the boxes loads into to blast freezer where its temperature cools down to less than 5C with one hour.
Thank you all for your responses, I have replied to your individual messages, plz do reply me. thanks again
Thanks for your reply, the other specie with green color colony is "vulnificus", so can you that what process we can adapt to kill this organism
Hi Nazia,
I note yr "may be" comment in Post 7.
Please be informed that (a) various non-pathogenic vibrio species may and often do naturally occur in marine fish, (b) there are many, many, non-pathogenic species of Vibrio family (and some other micro. families) that may give green or yelllow colonies on TCBS agar et al. Basically the observation of only such a colour is insufficient evidence to conclude any pathogenic Vibrio species is present.
How are you confirming presence of V.para/V.cholerae ? (V.vulnificus is also detailed in BAM*)
IMEX, the biochemical analysis for these specific species (esp last 2) can be lengthy and difficult (eg see BAM). Some labs may not have access to antisera, particularly for last 2 species.
However It is also feasible that yr raw material could be sufficiently contaminated with V.para etc that insufficient cooking does not achieve complete removal. Or associated utensils, etc may cause recontamination. You need some reliable micro. analyses to make further decisions.
Is yr "fish" derived from deep-sea origins or local/coastal/farmed sources ?
* BAM = USFDA Bacteriological Analytical Manual
Hi Nazia,
I note yr "may be" comment in Post 7.
Please be informed that (a) various non-pathogenic vibrio species may and often do naturally occur in marine fish, (b) there are many, many, non-pathogenic species of Vibrio family (and some other micro. families) that may give green or yelllow colonies on TCBS agar et al. Basically the observation of only such a colour is insufficient evidence to conclude any pathogenic Vibrio species is present.
How are you confirming presence of V.para/V.cholerae ? (V.vulnificus is also detailed in BAM*)
IMEX, the biochemical analysis for these specific species (esp last 2) can be lengthy and difficult (eg see BAM). Some labs may not have access to antisera, particularly for last 2 species.
However It is also feasible that yr raw material could be sufficiently contaminated with V.para etc that insufficient cooking does not achieve complete removal. Or associated utensils, etc may cause recontamination. You need some reliable micro. analyses to make further decisions.
Is yr "fish" derived from deep-sea origins or local/coastal/farmed sources ?
* BAM = USFDA Bacteriological Analytical Manual
we test the product in our in-house microbiological lab. we use TCBS agar for vibrio cholerae, which normally gives yellow colonies with this agar, but we also saw some green colonies, so we thought that this must be para or vulnificus. As we don't have the arrangements for specie identification, we have talked to some external labs to do this for us, lets c, I hope we will figure this out.
we check other things for possible contamination of vibrio like our utensils, cooking vessels, working tables, boxes in which we pack our curry, but also give negative results. this only found positive in our fish meat raw and in our final cooked curry. so now actually we are looking for possible methods to kill this organism, as we see that it resists the 80C and freezing temperature of -35 to -40 C (of blast freezer)
yes we catch the fish from deep-sea and its wild catch, we don't purchase from farms
we test the product in our in-house microbiological lab. we use TCBS agar for vibrio cholerae, which normally gives yellow colonies with this agar, but we also saw some green colonies, so we thought that this must be para or vulnificus. As we don't have the arrangements for specie identification, we have talked to some external labs to do this for us, lets c, I hope we will figure this out.
we check other things for possible contamination of vibrio like our utensils, cooking vessels, working tables, boxes in which we pack our curry, but also give negative results. this only found positive in our fish meat raw and in our final cooked curry. so now actually we are looking for possible methods to kill this organism, as we see that it resists the 80C and freezing temperature of -35 to -40 C (of blast freezer)
yes we catch the fish from deep-sea and its wild catch, we don't purchase from farms
Hi Nazia,
Thks comments.
I'm not familiar with Pakistan Micro Standards but various Countries have a RTE tolerance level for V.parahaemolyticus although afaik V.cholerae/V.vulnificus are usually zero-tolerant Globally. I enclose UK guidelines below -
UK, RTE Micro Pathogen Guidelines,.pdf 712.44KB 8 downloads
If there is a local tolerance, will be necessary to do a quantitative analysis. IMEX V.para is typically undetectable after cooking (MPN < 3cfu/g).
PS - Just to illustrate the biochemical complexities of Vibrio Family -
Vibrio biochemical properties.png 419.77KB 0 downloads
Hi Nazia,
Thks comments.
I'm not familiar with Pakistan Micro Standards but various Countries have a RTE tolerance level for V.parahaemolyticus although afaik V.cholerae/V.vulnificus are usually zero-tolerant Globally. I enclose UK guidelines below -
UK, RTE Micro Pathogen Guidelines,.pdf
If there is a local tolerance, will be necessary to do a quantitative analysis. IMEX V.para is typically undetectable after cooking (MPN < 3cfu/g).
PS - Just to illustrate the biochemical complexities of Vibrio Family -
thanks for your reply and help. this would be very helpful for my further work.