Incidence Levels of Enteric Pathogens and Microbial Quality of Raw Vegetables in Mashhad, Iran

مجله پژوهشهای علوم و صنایع غذایی ایران

Article 4, Volume 9, Issue 1 - Serial Number 23, April 2013   

Document Type: Research Article

DOI: 10.22067/ifstrj.v9i1.22970

Authors

Masoumeh Bahreini^{* 1}; Mohammad Bagher Habibi Najafi²; Mohammad Reza Bassami²; Morteza Abbaszadegan³

¹Ferdowsi University of Mashhad

²Department of Food Science and Technology, Ferdowsi University of Mashhad, Mashhad, Iran.

³Department of FoodMicrobiology, Arizona State University

Abstract

We investigated the microbiological quality of raw vegetables in Mashhad, Iran. In order to document the incidence of indicator and pathogenic microorganisms in this area. ninety eghit raw vegetable samples collected during 7 months were analyzed. All samples were examined for the presence of aerobic mesophilic bacteria, coliforms, Enterobacteriaceae, Escherichia coli, Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus, yeast and mould. Our data showed that the incidence levels of aerobic mesophilic bacteria was less than 107 cfu/g on 83% raw vegetables and 100% of raw vegetables were contained Entrobacteriace and total coliforms, and their range varied from 1 log to 6 log cfu/g. The mean counts of Lactic acid bacteria and yeasts and moulds were 4.1 log cfu/g and 4.5 log cfu/g, respectively, and the incidence levels of yeasts and moulds in 83% of raw vegetables was less than 5 log cfu/g. Our results were similar with other studies that determined microbial levels on raw vegetables. 12.7% of samples raw vegetables contained E.coli, but only 4.1% were higher than ≥ 2 log cfu/g. The incidence levels for E.coli O157:H7 and Salmonella on raw vegetables were 6% and 12.7% respectively. 94.9% of raw vegetables were contaminated with S. aureus and 7.8% of them were coagulase positive.

Keywords

Raw vegetables; Enteric pathogenic bacteria; Microbial quality; Incidence level

References

Abadias, M., Usall, J., Anguera, M., Solsona, C., and Vinas, I., 2008, Microbiological quality of fresh, minimally-processed fruit and vegetables, and sprouts from retail establishments. International Journal of Food Microbiology. 123: 121-129.

Beuchat, L. R., 1998, Surface decontamination of fruits and vegetables eaten raw: a review. WHO/FSF/FOS/98.2. Food Safety Unit. World Health Organization. URL: http://www.who.int/foodsafety/publications/fs_management/en/surface_decon.pdf.

Beuchat, L. R., 1996, Pathogenic microorganism associated with fresh product. Journal of Food Protection. 59: 204-216.

Carlin, F., Nguyen-the, C., Cudennec, P., and Reich, M., 1989, Microbiological spoilage of fresh, ready-to-use grated carrots. Science Aliments. 9: 371–386.

EU Scientific Committee on Food., 2002, Risk profile on the microbiological contamination of fruits and vegetables eaten raw. URL: http://europa.eu.int/comm/food/fs/sc/scf/out125_en.pdfs.visited 11 sep. 2010.

Food and Drug Administration, USA., 2006, Spinach and E. coli outbreaks. URL: http://www.fda.gov/oc/opacom/hottopics/spinach.html.

Heard, G., 1999, Microbial safety of ready-to-eat salads and minimally processed vegetables and fruits. Food Australia. 51: 414–420.

Health Protection Agency (HPA)., 2005a, Standard Methods for Food Products. Detection of Salmonella Spp. F13, Issue 3.1. HPA, London. Available from:

Health Protection Agency (HPA)., 2005b, Standard Methods for Food Products. Enumeration of Bacillus cereus and Other Bacillus species F15, Issue 1. HPA, London. Available from:

Health Protection Agency (HPA)., 2004a, Direct Enumeration of Escherichia coli.National Standard Method Standard F20, Issue 1 Available from:

Health Protection Agency (HPA)., 2004b, Enumeration of Staphylococcus aureus. National Standard Method: F12, Issue 1 Available from: < http://www.hpa-standardmethods.org.uk/documents/food/pdf/F12.pdf.06.02. 2009.

Johnston, L. M., Jaykus, L., Moll, D., Martinez, M. C., Anciso, J., Mora, B., and Moe, C. L., 2005, A field study on the microbiological quality of fresh produce. Journal of Food Protection. 68: 1840–1847.

Koopmans, M., and Duizer, E., 2004, Food-borne viruses: an emerging problem. International Journal of Food Microbiology. 90: 23-41.

Le Guyader, F. S., Mittelholzer, C., Haugarreau, L., Hedlund, K., Alsterlund, R., Pommepuy, M., and Svensson, L., 2004, Detection of noroviruses in raspberries associated with a gastroenteritis outbreak. International Journal of Food Microbiology. 97: 179-186.

Little, C. L., Roberts, D., Youngs, E., and De Louvouis, J., 1999, Microbiological quality of retail imported unprepared whole lettuce. A PHLS food working group study. Journal of Food Protection. 62: 325–328.

McMahon, M. A. S., and Wilson, I. G., 2001, The occurrence of enteric pathogens and Aeromonas species in organic vegetables. International Journal of Food Microbiology. 70: 155–162.

Mukherjee A., Spec D., Dyck E., and Diez-Gonzalez, F., 2004, Preharvest evaluation of coliforms, Escherichia coli, Salmonella, and Escherichia coli O157:H7 in organic and conventional produce grown by Minnesota farmers in the upper Midwest. Journal of Food Protection. 67: 894-900.

Nguyen-the, C., and Carlin, F., 1994, The microbiology of minimally processed fresh fruits and vegetables. Critical reviews in food science and nutrition. 34: 371-401.

Nguz, K., Shindano, J., Samapundo, S., and Huyghebaert, A., 2005, Microbiological evaluation of fresh-cut vegetables produced in Zambia. Food Control. 16: 623-628.

Olsen, S. J., MacKinon, L. C., Goulding, J. S., and Slutsker, L., 2000, Surveillance for foodborne disease outbreaks-United States. Morbidity Mortality Weekly Reported (MMWR). 49:1-51.

Ragaert, P., Devlieghere, F., and Debevere, J., 2007, Role of microbiological and physiological spoilage mechanisms during storage of minimally processed vegetables. Postharvest Biology and Technology. 44: 185–194.

Ruiz, B. G. V. et al., 1987, Contamination of fresh vegetables during cultivation and marketing. International Journal of Food Microbiology. 4:285-291.

Sagoo, S. K., Little, C. L., Ward, L., and Mitchell, R. T., 2003, Microbiological study of ready-to-eat salad vegetables from retail establishments uncovers a national outbreak of salmonellosis. Journal of Food Protection. 66: 403-409.

Salleh, N. A., Rusul, G., Hassan, Z., Reezal, A., Isa, S. H., Nishibuchi, M., and Radu, S., 2003, Incidence of Salmonella spp. in raw vegetables in Selangor, Malaysia. Food Control. 14: 475–479.

Schlech, W. F., Levigne, P. M., Bortolussi, R. A., Allen, A. C., Haldane, E. V., Wort, A. J., and Hightower, A. W., 1983, Epidemic Listeriosis-evidence for transmission by food. New England Journal of Medicine. 308: 203-206.