Why endospores are important

In the spring, when more food is available, they wake up and continue life as usual. Spore-forming bacteria are very similar! The spore in the coloring page below is represented by the thick, frilly oval with rings inside of it. Each ring represents a protective layer, and the squiggle in the center is the protected package of DNA.

Clostridium and Bacillus are two spore-forming genera 1 , which also contain several foodborne pathogens that can cause foodborne illness in humans. As a general rule, only a few disinfectants are strong enough to kill bacterial endospores within a short period of time. Usually they are strong oxidants like diluted bleach. Among antimicrobial devices, strong ultraviolet light-based systems are the best bet for endospore killing.

Breadcrumb Home Information. A vaccine is available for prevention, but it is ineffective for treatment of an acute infection. Antiserum is the only antidote for tetanospasmin toxin. Clostridium botulinum is a spore forming anaerobic bacterium that causes food poisoning. Food borne botulism occurs when the food is contaminated with either spores or toxin. Improperly preserved food and contaminated honey are associated with this disease. Botulism toxin is a neurotoxin which blocks the transmission of nerve impulses to muscle causing a flaccid paralysis.

Clostridium difficile is an opportunistic, spore-forming, gram-positive, anaerobic bacillus. It is transmitted from one patient to another through direct or indirect contact, through the oral ingestion of its vegetative cells or endospores i.

In fact, the primary reservoirs of C. The setting of a contaminated environment coupled with the use of broad spectrum antibiotics can produce a situation that upsets the balance of normal colon bacteria. In the case of C. The treatment is long and difficult, using potent antibiotics and requiring lengthy hospital stays. This infection can leave the patient weak and debilitated for a long period, lengthening recovery from surgery or other medical conditions.

For botulinum toxin-producing clostridia, prevalence ranges from 5. In that study, a higher prevalence was observed in nonvirgin soil i. Also in soil collected in honey-producing apiaries in Finland, a high prevalence of C. This indicates that soil-derived spores of C. Honey is one of the most important sources of and the only proven food item associated with C. Besides neurotoxigenic species, several Clostridium species occurring in soil are important as spoilers of processed foods such as the REPFED foods with modified atmosphere packaging vacuum or anaerobic atmosphere and semihard cheeses.

This explains the fact that in modern food processing with mild processing e. Under these conditions, the growth of aerobic bacteria is restricted and thus shelf life extended, but it can also provide an environment conducive to the growth of anaerobic bacteria such as clostridia.

The use of HACCP for the production of chilled foods is specified in European hygiene laws, and a number of guidelines, advice, and recommendations exist emphasizing the importance of HACCP and chill storage. The number of botulism cases caused by ready-to-eat food consumption has increased and has been reported worldwide during the last 25 years [ 57 ].

Although most botulism cases and C. A literature examination has indicated that, given the fact that nonproteolytic C. Nevertheless, precise safety margins with respect to food-borne botulism seem not to be well defined for these food products, and changes in industrial practice e.

Several psychrophilic and psychrotolerant species including C. Of these species, C. These two spoilage clostridial species have been found frequently in beef slaughterhouses and their environments, especially at areas prior to hide removal [ 14 ]. It is therefore assumed that hides and feces are the main reservoirs for these organisms in the slaughterhouse.

There is no evidence that these clostridia are present in the gut of farm animals. Both C. Spores of butyric acid bacteria can cause spoilage of semihard cheeses with long ripening times such as Gouda and Emmenthaler. Mostly Clostridium tyrobutyricum is implicated in the so-called late blowing defect of this kind of cheeses.

This organism is able to convert lactic acid into butyric acid with the concomitant production of CO 2 and H 2 gas at relatively low pH. As an anaerobic spore former, it survives pasteurization and will grow in semihard cheese resulting in off-flavors and excessive gas formation.

The Dutch dairy industry wants to ensure a contamination level of butyric acid spores below a maximum spore limit MSL of spores per liter raw milk [ 62 ]. In a modeling study as well as a year-long survey on 24 Dutch dairy farms, it was found that the contamination level of silage is the most important factor for the contamination level of farm tank milk: feeding silage containing not more than 3 log butyric acid spores per gram, combined with a basic pretreatment of the teats before milking, is sufficient to assure the MSL [ 62 , 63 ].

Hygiene measures aiming at improving the barn hygiene and decreasing the transmission of spores, originating directly from soil during milking, and reducing the contamination level of other feed seemed to contribute only marginally to an improvement of the control of the contamination of farm tank milk with butyric acid spores.

However, undoubtedly the primary source of these spores in silage is soil which contains high levels of butyric acid spores mean of 4. One of the risk factors associated with high levels of spores in silage is the initial contamination of silage with soil via enclosure of soil during harvesting. In many types of food and feed, soil can be considered as the initial contamination source for spore formers. Usually, when direct transfer from soil is involved, levels of these spore formers in foods, ingredients, or feeds are too low to cause problems.

However, because of the complexity of the food chain, particular spore-forming species or types may encounter niches where proliferation occurs. This can happen on the primary production level e. These proliferation steps enable the endospore former such as B. For the food industry, it is a challenge to gain insight into the whole contamination flow of endospore formers originating from soil as well as in the conditions permitting their proliferation.

This is an open access article distributed under the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Article of the Year Award: Outstanding research contributions of , as selected by our Chief Editors.

Read the winning articles. Journal overview. Special Issues. Academic Editor: Ismail Saadoun. Received 28 Feb Accepted 05 Jul Published 21 Sep Abstract Specific endospore formers have become important contaminants in industrial food processing.

Introduction There is a clear association between soil-borne endospore forming bacteria and food contamination. Figure 1. Electron micrograph of a B. Adapted from Scheldeman et al. Table 1. Phylogenetic structure of the B. Table 2. Recent data on presence of B. Figure 2. Contamination routes of spores of B. The importance of contamination sources and routes is indicated by the size of arrow.

References A. Andersson, U. Ronner, and P. View at: Google Scholar P. Scheldeman, L. Herman, S. Foster, and M. Thompson, A. Sorokin et al. Vilain, Y. Luo, M. Hildreth, and V. Jensen, B. Hansen, J. Eilenberg, and J. Carlin, J. Brillard, V. Broussolle et al. Vissers, M. Driehuis, P. De Jong, and J.