Occurrence of Enterococcus spp. isolated from the milk and milk products
DOI:
https://doi.org/10.5219/476Keywords:
enterococci, PCR, raw cow’s milk, colostrum, wheyAbstract
Enterococcus spp. is the most controversial group of lactic acid bacteria that have been for years ascribed with beneficial or detrimental role in food and feed. The aim of our study was to monitor the occurrence of Enterococcus spp. as the indicator of the contamination from collected samples of raw cow's milk, goat's colostrum and whey (n = 186). Cultures of enterococci were cultivated and purified and identified by the genus-specific and species-specific PCR method (n = 230). Among suspected isolates in total 222 isolates (96.5%) were identified as Enterococcus spp. The results were the same in all samples separately, more than 90% each of them were positive to Enterococcus spp. The results of counting the number of cultivated colonies showed that the largest number of enterococci is found in the samples of whey taken after the process of electrodialysis and the smallest in the native whey sample. From collected whey samples, 64 samples (90%) were PCR positive for enterococci species. Afterwards within the identification of several selected isolates that were identified, as Enterococcus spp. by the species-specific PCR method the most frequently presented in all of isolates was Enterococccus faecalis. Apparently the presence of enterococci was detected in all samples, but in amounts that aren't hazardous for human health. Although enterococci are oportunistic pathogens, it seems that they occur frequently in foods (especially fermented) in large numbers.
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Citak, S., Gundogan, N., Mend, A., Orhan, S. 2006. Occurence, isolation and antibiotic resistence of Enterococcus species isolated from raw milk samples in Turky. Milchwissenschaft-Milk science international, vol. 61, no. 2, p. 150-152.
FAO (Food and Agriculture Organization of the United Nations) [online] [cit. 2015-02-02] Available at: http://www.fao.org/home/en/
Foulquié, M. R., Sarantinopoulos, P., Tsakalidou, E., De Vuyst, L. 2006. The role and application of enterococci in food and health. Int. J. Food Microbiol., vol. 106, no. 1, p. 1-24. https://doi.org/10.1016/j.ijfoodmicro.2005.06.026 PMid:16216368 DOI: https://doi.org/10.1016/j.ijfoodmicro.2005.06.026
Franz, C.M.A.P., Huch, M., Abriouel, H., Holzapfel, W., Gálvez, A. 2011. Enterococci as probiotics and their implication in food safety. Int. J. Food Microbiol., vol. 151, no. 2, p. 125-140. https://doi.org/10.1016/j.ijfoodmicro.2011.08.014 PMid:21962867 DOI: https://doi.org/10.1016/j.ijfoodmicro.2011.08.014
Giraffa, G. 1999. Enterococcus. Encyclopedia of food microbiology. London, UK: Accademic Press, p. 617-624. ISBN 0-12-227070-3 https://doi.org/10.1006/rwfm.1999.0520 DOI: https://doi.org/10.1006/rwfm.1999.0520
Giraffa, G. 2003. Functionality of enterococci in dairy products. Int. J. Food Microbiol., vol. 88, no. 2-3, p. 215-222. https://doi.org/10.1016/S0168-1605(03)00183-1 DOI: https://doi.org/10.1016/S0168-1605(03)00183-1
Guo, M. 2003. Encyclopedia of Dairy Sciences. Goat / Milk. Fuquay, London, UK: Accademic Press p. 2944-2949. ISBN: 978-0-12-374402-9 https://doi.org/10.1016/B0-12-227055-X/00565-4 DOI: https://doi.org/10.1016/B0-12-227055-X/00565-4
Hernández-Castellano, L. E., Morales-delaNuez, A., Sánchez-Macías, D., Moreno-Indias, I., Torres, A., Capote, J., Argüello, A., Castro, N. 2015. The effect of colostrum source (goat vs. sheep) and timing of the first colostrum feeding (2 h vs. 14 h after birth) on body weight and immune status of artificially reared newborn lambs. J. Dairy Sci., vol. 98, no. 1, p. 204-210. https://doi.org/10.3168/jds.2014-8350 PMid:25468691 DOI: https://doi.org/10.3168/jds.2014-8350
ISO 6887-1:1999, Microbiology of food and animal feeding stuffs - Preparation of tests samples, initial suspension and decimal dilutions for microbiological examination - Part 1: General rules for the preparation of the initial suspension and decimal dilutions.
ISO 7218:2007, Microbiology of food and animal feeding stuffs - General requirements and guidance for microbiological examinations.
Jackson, C. H., Fedorka-Cray, P. J., Barrett, J. B. 2004. Use of a genus- and species-specific multiplex PCR for identification of enterococci. Journal of Clinical Microbiology, vol. 42, no. 8, p. 3558-3565. https://doi.org/10.1128/JCM.42.8.3558-3565.2004 PMid:15297497 DOI: https://doi.org/10.1128/JCM.42.8.3558-3565.2004
Jelen, P. Whey processing-Utilization and Products. Fuquay, J. W. Encyclopedia of Dairy Science. London, UK: Academic Press, 2002, p. 2739-2745. ISBN: 978-0-12-374402-9 DOI: https://doi.org/10.1016/B0-12-227235-8/00511-3
Kagkli, D. M., Vancanneyt, M., Hill, C., Vandamme, P., Cogan, T. M. 2007. Enterococcus and Lactobacillus contamination of raw milk in a farm dairy environment. Int. J. Food Microbiol., vol. 114, no. 2, p. 243-251. https://doi.org/10.1016/j.ijfoodmicro.2006.09.016 PMid:17189657 DOI: https://doi.org/10.1016/j.ijfoodmicro.2006.09.016
Khan, H., Flint, S., Yu, P. L. 2010. Enterocins in food preservation. Int. J. Food Microbiol., vol. 141, no. 1-2., p. 1-10. https://doi.org/10.1016/j.ijfoodmicro.2010.03.005 PMid:20399522 DOI: https://doi.org/10.1016/j.ijfoodmicro.2010.03.005
Pescuma, M., Hébert, E. M., Mozzi, F., Font de Valdez, G. 2008. Whey fermentation by thermophilic lactic acid bacteria: Evaluation of carbohydrates and protein content. Food Microbiology, vol. 25, no. 3, p. 442-451. https://doi.org/10.1016/j.fm.2008.01.007 PMid:18355669 DOI: https://doi.org/10.1016/j.fm.2008.01.007
Pieniz, S., Andreazza, R., Anghinoni, T., Camargo, F., Brandello, A. 2014. Probiotic potential, antimicrobial and antioxidant activities of Enterococcus durans strain LAB18s. Food Control, vol. 37, p. 251-256. https://doi.org/10.1016/j.foodcont.2013.09.055 DOI: https://doi.org/10.1016/j.foodcont.2013.09.055
Salminen, S., Von Wright, A., Ouwehand, A. 2005. Lactic acid bacteria: microbiological and functional aspects, 3rd revised and expanded edition. Clinical Infectious Diseases [online], vol. 40, p. 911-912 [cit. 2015-02-02]. ISSN: 1537-659. Retrieved from the web: http://cid.oxfordjournals.org/content/40/6/911.full.pdf+html DOI: https://doi.org/10.1086/428129
Tratnik, L. J., Božanić, R. 2012. Milk and milk products. Zagreb, Croatia: Croatian Milk Associations. ISBN 978-953-7472-06-1
Uruakpa, F. O., Ismond, M. A. H., Akobundu, E. N. T. 2002. Colostrum and its benefits: a review. Nutrition Research, vol. 22, no. 6, p. 755-767. https://doi.org/10.1016/S0271-5317(02)00373-1 DOI: https://doi.org/10.1016/S0271-5317(02)00373-1
Zulueta, A., Maurizi, A., Frígola, A., Esteve, M. J., Coli, R., Burini, G. 2009. Antioxidant capacity of cow milk, whey and deproteinized milk. International Dairy Journal, vol. 19, no. 6-7, p. 380-385. https://doi.org/10.1016/j.idairyj.2009.02.003 DOI: https://doi.org/10.1016/j.idairyj.2009.02.003
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