17-Sanitation Chemical Products and their Effectiveness on Biofilms – a Review

https://www.agriculturejournals.cz/publicFiles/02507.pdf 

Biofilms and Hygiene on Dairy Farms and in the Dairy Industry: 

Sanitation Chemical Products and their Effectiveness on Biofilms – a Review 

Hana VLKOVÁ1 , Vladimír BABÁK1 , Růžena SEYDLOVÁ2 , Ivo PAVLÍK1 and Jarmila SCHLEGELOVÁ1 1 Department of Food and Feed Safety, Veterinary Research Institute, Brno, Czech Republic; 2 Dairy Research Institute, Prague, Czech Republic

Abstract 

Vlková H., Babák V., Seydlová R., Pavlík I., Schlegelová J. (2008): Biofilms and hygiene on dairy farms and in the dairy industry: sanitation chemical products and their effectiveness on biofilms – a review. Czech J. Food Sci., 26: 309–323. 

Microbial biofilms which form on all types of surfaces of technological systems in the dairy industry and on dairy farms adversely affect the quality and safety of final products, i.e. both foodstuffs and raw materials used for their production. The fact that a number of microorganisms are alimentary pathogens, e.g. Staphylococcus aureus or Listeria monocytogenes, makes a serious problem directly affecting human health. Biofilms are usually formed by various species of microorganism, which protect each other against the effects of biocidal (antibacterial) agents and are resistant to these agents. The colonisation of surfaces of the open and closed piping systems, floors, waste, walls and ceilings of the production halls becomes a major problem in the selection of effective sanitation agents for their control. Based on the existing model studies, practical methods for testing the effectiveness of sanitation procedures should be evaluated, including the selection of biocides and comparison of the physical parameters of the sanitation procedures. Testing the effectiveness of the sanitation agents should be performed with the use of standardised tests, which consider microbial, structural, and chemical characteristics of the living microbial communities on specific contact surfaces in the food-processing industry. 

Keywords: microbial communities; food process surfaces; mechanisms of resistance; food safety

(1)Basic suspension test EN 1040 works with microorganisms Pseudomonas aeruginosa ATCC 15442 and S. aureus ATCC 6538 for bactericidal test Candida albicans ATCC 10231 and Aspergillus niger ATCC 16404 for fungicidal tests. 

(2)Quantitative suspension tests for the agents used in the food industry EN 1276 and for the biocides used in the sphere of veterinary care EN 1656 work with S. aureus ATCC 6538, P. aeruginosa ATCC 15442, E. coli ATCC 10536, Enterococcus hirae ATCC 10541 for germicidal tests, C. albicans ATCC 10231 and A. niger ATCC 16404 for fungicidal tests; the above mentioned tests for the evaluation of bactericidal activity work with two methods: dilution neutralisation method and method of membrane filtration. 

(3)Quantitative surface test on non-porous surface EN 13697 works with the same microorganisms as the basic suspension test; however, the contact time of the agents with the surface located culture is 5 min for bacteria and 15 min for fungi. 

(4)Test for the evaluation of sporocidal activities EN 13704 employs Bacillus subtilis ATCC 6633 as the test strain. (

5)The conditions for storage of the control microorganism strains have been set by EN 12353 test......

Conclusions 

The current knowledge can be summarised as follows: 

(1)Microbial biofilms that can be formed on all types of surfaces of technological systems on farms and in the dairy industry adversely affect the quality and safety of the final products (many microorganisms are alimentary pathogens), both processed raw materials and food products. 

(2)The biofilms are mostly formed by different species of microorganisms, which mutually protect one another against the effects of biocidal products and are concurrently resistant to these products. The colonisation of surfaces in the closed piping systems, open systems, floors, waste, walls and ceilings in the production halls by microorganisms represents a problem in the selection of sanitation agents effective for their devitalisation.

 (3)Based on the existing and new model studies, practical methods for measuring the effectiveness of the sanitation procedures, including the selection of biocides and comparison of the physical parameters of the sanitation procedures, should be evaluated. The testing the sanitation agents should be performed by standardised tests, which will consider microbial, structural and chemical properties of the viable surface communities of microorganisms on specific contact surfaces in the food processing industry.

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Corresponding author:

 RNDr. Jarmila Schlegelová, Výzkumný ústav veterinárního lékařství, v.v.i., Hudcova 70, 621 00 Brno, Česká republika tel.: + 420 533 331 619, fax: + 420 541 211 229, e-mail: schlegelova@vri.cz