Spices - Implication in cases or outbreaks of diseases caused by microbial contamination of food origin: culture and phenotypic and molecular identification.
Spices are important food commodities and are among the ingredients in many foods, being used throughout the world in the preparation of meals, generally in small quantities in order to aromatizarlas. They are obtained from fruits or seeds of plants such as paprika (paprika), barks of plants such as cinnamon (cinnamon), roots or rhizomes like turmeric (turmeric) and ginger (ginger), or leaves as oregano (oregano) or bay (bay leaf), among others. Are considered low moisture foods (Low-Moisture Foods -LMFs-), stable environmental (Ambient-stable AS) and low risk (Low-Risk Foods -LRFs-). The LMFs are defined as foods having a water activity (a w) less than 0.85. In general, a low water activity which facilitates the growth of bacteria is 0.87, although in some optimal conditions bacteria such as Staphylococcus aureus can grow with an activity of 0.83. As spices are considered LMFs, AS and LRFS is admitted that is unlikely to lead to foodborne illness. However, in recent years there has been an increasing number of implications of spices as a source of pathogens, causing isolated cases or outbreaks of foodborne illness due to contamination with pathogenic bacteria.
The use of spices in food preparation precisely, it is considered that could be motivated to protect them from degradation by bacteria or fungi. Favorable to this hypothesis argue that in countries with higher temperatures spices are used more often and quantity than in countries with colder temperatures. Therefore, in countries with warmer climates, where the proliferation of microorganisms in food, almost all recipes meats have at least one spice, or sometimes many, it would be more feasible while in countries with cold climates there are a large number of dishes without spices or with only a few. Countries like Thailand, the Philippines, India and Malaysia are at the forefront of high temperatures and consume spicy foods, while countries such as Sweden, Finland and Norway have low temperatures and consume few spices. Other justify the use of spices in countries with hot climates and high humidity with the hypothesis eat to sweat (eat-to-sweat), because when ingesting sweating would increase, although for others this hypothesis valueless because no all spices make you sweat.
Antimicrobial effect of spices
Garlic, onions, allspice, oregano, microbial inhibitors are considered, but also other also have antimicrobial activity. In order of importance for antimicrobial activity we can mention the following 30: garlic (garlic), onion (onion), allspice (allspice), oregano (Oregano), thyme (thyme), cinnamon (cinnamon), tarragon ( tarragon), cumin (cumin), cloves (clove), lemon grass (lemon grass), bay leaves (bay leaf), capsicum chili or spicy (capsicum, chilies, hot peppers), rosemary (rosemary), marjoram (marjoram), mustard (mustard), caraway (caraway), peppermint (mint), salvia (sage), fennel (fennel), cilantro (coriander), dill (dill), nutmeg (nut meg), basil (basil) parsley (parsley), cardamom (cardamom), black pepper and white (white and black pepper), ginger (ginger), anise seeds (anise seed), seed of celery (celery seed) and lemon juice or lime ( lemon or lime).
The first 8 above would kill 80% of bacteria; chili peppers and chillies would kill 75% of bacteria; the white or black pepper, ginger, anise seed, or lemon juice or lime would kill 25% of bacteria.
Factors involved in microbial contamination of spices
Some imported spices are contaminated with potentially pathogenic microbes such as bacteria or fungi. Contamination can occur when the fruits, leaves or bark of plants of the obtained, dried in the sun for after spices. While drying are accessible to insects, reptiles and other animals. Once dried, these plant parts are milled to give spices as known for consumption. When the plants are grown, sometimes they are grown in places where they meet polluted water or land, which easily contaminated with pathogenic microorganisms.
Hot humid climates of places where the plants are grown for spices, low health conditions of cultivation, collection of processing, or storage, contributing to easy contamination. In many cases, harvesting conditions are inadequate, polluted water are used, the drying time is prolonged, all of which contribute to possible contamination. Once they prepared usually stored in large quantities without packaging, which may be contaminated with dust, sewage, animal excrement or human.
Survival of microorganisms in foods with low humidity (LMF: Low Moisture Foods)
The low water activity (a w) in food low humidity (LMFs), as with spices, would suggest that it would be unlikely that spices encontrasen bacteria. However, it has shown that some microorganisms can survive in LMFs for extended periods of time. For example Chronobacter spp. you can do it in milk powder; Salmonella spp. in chocolate, dried animal feed, spices, butter or nuts, among others; Salmonella enteritidis, Escherichia coli and Klebsiella pneumoniae can survive in milk powder up to 15 months; Chronobater (Enterobacter sakazakii), E. vulneris and Klebsiella oxytoca can be recovered at 2 years; Salmonella spp. LMFs can survive for weeks, months or years.
The mechanism by which bacteria can survive in LMFs is not completely understood. Admittedly it depends on the ability of bacteria to adapt to high osmotic potentials or dry conditions. In LMFs, microorganisms adapt osmolarity balancing cell inside with the medium where they are to prevent water loss. This can achieve by mechanisms such as the uptake of K + ions, the uptake of solutes electrochemically neutral low molecular weight (proline, glycine, ...), the development of protective biofilms composed of cellulose as performed Chronobacter spp., Which also allow the adhesion to hydrophilic and hydrophobic surfaces.
Salmonella spp, in environments with low humidity (LME: Low Moisture Environment). Low water activity (a w) form filaments and elongated cells, thanks to generate inhibitors of cell division. In the filamentous increase their desiccation tolerance. Furthermore, in the LMEs environments can be composed of fimbriae and cellulose biofilms.
Microorganisms involved in isolated cases or outbreaks by ingestion of spices
Scientific evidence suggests that spices available in the outlets may be contaminated with pathogenic microorganisms, so some studies conclude that may be high risk products be contaminated and can be a problem for consumers.
Salmonella spp. has been and is the main pathogen related to spices in the US Between 1970 and 2003 , 21 incidents with 12 kinds of spices, and found them Salmonella spp. It was involved in 95% of documented cases (20/21).
Between 2008 and 2011, the "Rapid Alert System for Food and Feed" the European Commission reported 22 alerts spices, of which 21 were due to Salmonella spp. and Escherichia coli. In Canada, the Canadian Food Inspection Agency (CFIA), collected a large number of spices in 2014 (paprika powder, white pepper, ground black pepper, flax seeds, ground carob, rosemary leaves, oregano dried leaves, and in all cases in which contamination was involved Salmonella spp was detected.
The main bacteria found in various food incidents have been (in alphabetical order) the following:
- Bacillus cereus (spores).
- Cronobacter spp. (previous Enterobacter sakazakii), considered an opportunistic pathogen.
- Clostridium botulinum.
- Clostridium perfringens (spores).
- Escherichia coli.
- Verotoxigenic Escherichia coli (VTEC; EHEC) O: 157; H: 7.
- Listeria monocytogenes.
- Salmonella spp.
- Staphylococcus aureus.
Other bacteria have occasionally been found:
- Acinetobacter spp.
- Aeromonas salmonicida.
- Chromobacterium violaceum.
- Enterobacter agglomerans.
- Enterobacter cloacae.
- Flavobacterium spp.
- Pseudomonas aeruginosa.
- Pseudomonas cepacia.
- Pseudomonas putida.
- Serratia plymuthica.
All of them are considered more important for its impact Salmonella spp., Bacillus cereus and Clostridium perfringens.
Some known outbreaks of disease from spices
In a 2006 publication (Vij V, Ailes E, Wolyniak C, Angulo FJ, Klontz KC Recalls of spices due to bacterial contamination monitored by the US Food and Drug Administration.. The predominance of Salmonellae J Food Protect, 2006, 69: 233-237), the increase in related incidents indicated spices, so they analyzed what happened between 1970 and 2003. in those years 21 incidents involving 12 spices contaminated with bacteria, responsible were monitored in all of them except one , Salmonella spp. and most involved paprika and spice from several countries.
Publication 2013 (Van Doren JM, Neil KP, Parish M, Gieraltowski L, Gould LH, Gombas KL Outbreaks Foodborne illness from microbial contaminants in spices, 1973-2010 Food Microbiol 2013, 36:... 456-464), discloses 14 outbreaks due to contamination of spices that occurred between 1973 and 2010 in countries such as Canada, Denmark, England and Wales, France, Germany, New Zealand, Norway, Serbia and USA.,. These outbreaks affected 1,946 people, of whom 128 were hospitalized and two of them died. In 70% of cases were caused by foods to which spices had been added at the end of cooking. Salmonella enterica was found in 71% of outbreaks (10/14) producing 87% of cases of disease found and Bacillus spp. in 29% (4/10) to yield 13% of cases of disease. In 71% of cases the outbreaks were caused by spices from seeds or fruits of plants.
In a study by the US FDA wherein shipments spices from 79 countries to see if contained Salmonella were investigated. The found in 37 of the 79 deliveries which represented a prevalence of Salmonella spp. 6.6% of shipments between 2007 and 2009, twice that found in other food imports. They also found that 12% of the shipments contained insects or other vermin as animal hair.
Some outbreaks of foodborne illness due to published spices:
- 1974 - Canada: salmonellosis due to black pepper (17 cases).
- 1993 - Germany: salmonellosis due to crisps (chips) seasoned with black pepper (1,000 cases).
- 2007 - US .: salmonellosis in many states by broccoli powder blend of spices used in a children herbal preparation (69 cases, mostly -93% of cases in children under 3 years).
- 2009 - US .: salmonellosis due to added black pepper and ready to eat a salami (272 cases from 44 states) red pepper.
- 2005-2015 - Several countries: about 9,000 outbreaks caused by Salmonella spp, Bacillus cereus and Clostridium perfringens.. These three bacteria are the pathogens involved and the only related outbreaks.
Usually, the spices are added to foods during cooking, so should be contaminated with pathogenic bacteria, they would be destroyed unless they are added shortly before the end of cooking, usual practice to avoid loss of aromas, in which case some bacteria and especially as the sporulated Bacillus cereus and Clostridium perfringens, are not destroyed. However, when added to cold or precooked dishes, not eliminated and if present in the added spice arrive viable consumer.
Treatment of spices before commercial distribution to eliminate pathogenic bacteria poses some problems to avoid losing their organoleptic characteristics. For this reason, the heat treatment can not be applied. As an alternative to heat sterilization sterilization with ethylene oxide is proposed. This method is not available to retailers and distributors only be considered for large distributors. Moreover, this method lacks action against bacterial spores of Bacillus spp. or Clostridium spp. Another very effective, not accessible to most distributors alternative is irradiation with a maximum dose of 30 Kilogray (3 Mrad).
Tests in IVAMI:
- Qualitative or quantitative culture.
- Molecular identification of bacteria or fungi.
Recommended types of samples:
- Spices (amount 100 g).
Shipping and storage conditions:
- Refrigerated for less than 2 days and shipping within cork white box pack (frigolín) frozen.
Delivery time :
- Cultivation: 3 to 5 working days depending on the speed of growth.
- Molecular identification: 3 to 5 working days.
Cost of testing:
- Consult firstname.lastname@example.org .