Occurrence of Staphylococcus and enteropathogens in soft cheese commercialized in the city of Rio de Janeiro, Brazil (original) (raw)
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The consumption of raw milk cheese has been growing worldwide with S. aureus and E. coli been the leading agents in food poisoning. The present work aims to evaluate the microbiological quality of raw milk cheeses commercialized in Brazil, regarding microbiology safety and enterotoxin gene presence. Forty-three raw milk cheeses samples from five different suppliers were analyzed. Counting and identification of S. aureus, E. coli and Salmonella spp were performed according to BAM from the FDA. Further S. aureus identification was performed by the cydB and Salmonella spp by the invA gene. S. aureus toxin genes (sea, seb, sec, see, ses, seh and sei) and E. coli gene LT, STa, Stb, stx1, stx2, eae, rmpA, wabG, mrkD, kfu, mcgA, fimH and uge were analysed. From the 43 samples analyzed, 18 presented S. aureus with two isolates positive for the tst gene, two for the sec gene, two for the seh gene and four for the sei gene. Thirty-five E. coli and seven. Salmonella spp isolates were obtained. E. coli isolates harbored sta and stx2 genes. The results revealed that raw milk cheeses sold can cause harm consumer's health and highlights the importance of adoption good hygienic-sanitary practices and consumers awareness.
A Review for Cheese Microbial Risk Assessments
Asian-Australasian Journal of Animal Sciences, 2015
European Union (Kousta et al., 2010). Many of these foodborne outbreaks were a result of contamination with Staphylococcus aureus, and this was not surprising as S. aureus often causes mastitis in cows, leading to milk contamination (Rabello et al., 2007). Additionally, in the USA, S. aureus and Listeria monocytogenes were isolated from unpasteurized soft cheese on sale in California, which was smuggled into the USA from Mexico in 2010 (MDA, 2010). This implication may have resulted from the properties of soft cheese like the high water activity and low acidity as well as improper sanitation that is common route for pathogenic bacteria to contaminate the cheese during cheese-making process (Gould et al., 2014). Further, L. monocytogenes was often found in soft cheese, which has high moisture content: 67% of moisture on a fat-free basis or ≥50% of moisture content (Codex, 2000; FDA, 2012a). This data suggest that cheese may pose a significant risk to consumers (Janštovă et al., 2014). Given this picture, strict guidelines have been established to control foodborne pathogens in cheese, especially for L. monocytogenes (FDA, 2003; EFSA/ECDC, 2011). For instance, for cheese with an Open Access Asian Australas. J. Anim. Sci.
Journal of food protection, 2007
Seventy raw milk cheeses made in different regions of Portugal, both hard and soft varieties, made with cow's, ewe's, or goat's milk or combinations of these, were sampled within their quoted shelf lives for microbiological safety. On the basis of the presence or numbers of Escherichia coli, E. coli O157, Staphylococcus aureus, Salmonella, and Listeria monocytogenes, cheeses were categorized as satisfactory, acceptable, unsatisfactory, or unacceptable and potentially hazardous. Twenty-two of the 70 cheeses were classified as satisfactory or acceptable. Thirty-seven of the cheeses were considered unsatisfactory because of the presence of E. coli, S. aureus, or both, while 11 of the cheeses were graded as unacceptable and potentially hazardous because of the presence of excessive numbers of S. aureus, E. coli, or L. monocytogenes and the presence of Salmonella in three of these. All cheeses graded as unacceptable and potentially hazardous were soft or semisoft cheeses made...
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Food Control, 2010
Cheeses, even though characterized as safe for consumption, have been implicated in foodborne outbreaks associated with severe symptoms and high fatality rate. The foodborne pathogens in raw milk originate from the farm environment and direct excretion from animals infected udder, whereas in dairy plants the pathogens may enter via contaminated raw milk, colonize the dairy plant environment and consequently contaminate dairy products. Important source of contamination during the handling and processing might be the workers as well. The objective of this study was to review literature on the prevalence of pathogens in various types of cheese, raw milk and dairy environment, identify sources of contamination and present concisely prevention measures for farm and dairy plant.
Detection of some microorganisms of public health hazards in cheese
مجلة سوهاج لشباب الباحثين
In this study, the microbial quality of Domiati, Kareish, and Ras cheeses was studied. A total of 150 cheese samples were collected, and samples were analyzed for total coliforms, fecal coliforms, Escherichia coli, Staphylococcus aureus, yeast, and mold counts. The highest distribution of coliforms was lied in 10-< 10 2 (26 %), 10 3-< 10 4 (60 %) and 10 3-< 10 4 (32 %) in Domiati, Kareish and Ras cheese respectively, 30, 18 and 16% of fecal coliforms samples had counts of 10-< 10 2 , while 2, 4 and 16 % had counts of 10 2-< 10 3 , and 2, 30 and 34 % had counts of 10 3-< 10 4. E. coli existed in 28, 28 and 37% of samples, respectively. Staph. aureus was detected in 26, 10 and 22 % of samples respectively, with average count of 1.27 x 10 3 , 7.5 x 10 4 and 2.15 x 10 3 respectively. Yeasts were detected in 98, 96 and 52 % of samples respectively, with average count of 3.88 x 10 5 , 3.26 x 10 5 and 1.04 x 10 4 respectively. Molds were detected in 46, 32 and 35 % of samples with average values of 3.9 x 10 4 , 1.2 x 10 4 and 2.61 x 10 4 , respectively. The presence of these organisms reflects unhygienic measures, inadequate heat treatment, using bad quality ingredients and improper sanitation during handling and storage.
Detection of enterotoxigenic and antimicrobial resistant S. aureus in Turkish cheeses
Food Control, 2012
Staphylococcus aureus is a very common microorganism present on the skin and mucosae of humans and animals, and in the environment. Contamination of milk and dairy products may occur directly from infected food producing animals or may result from poor hygiene during production processes or at the retail and storage stage. This study reports the results of an investigation on the presence of enterotoxigenic and antimicrobial resistant S. aureus in Turkish cheeses. A total of 200 unpackaged cheese samples were examined and 19 of them (9.5%) were found to contain coagulase positive Staphylococci (CPS). In 12 samples (6%) S. aureus the mean was 4.31 log cfu/g. Three out of 12 S. aureus strains were found to be enterotoxigenic and two of the three produced only SEC type, one of them produced SEC and SED together. Two of the 12 S. aureus strains were mecA positive. Methicillin-resistant Staphylococcus aureus (MRSA) strains were found to be enterotoxigenic; one strain synthesisedsynthesised SEC and one SEC þ SED. In this study, 10 out of 12 strains were found to be resistant to one or more antibiotics tested by the disk diffusion method. All strains were susceptible to vancomycin, gentamicin and imipenem. The results indicate that the presence of enterotoxigenic and antimicrobial resistant strains of S. aureus in cheese constitute a potential risk for public health. This calls for better control of cheese contamination sources and taking hygienic measures is necessary for food safety.
Food Science and Technology, 2019
Microbial quality and the prevalence of foodborne pathogens (E. coli 0157:H7, Salmonella spp., Listeria monocytogenes and Campylobacter jejuni) of cheeses sold at three retail points (supermarkets [SM], street markets [ST], and convenience grocery stores [CGS]) in Chihuahua, Mexico, were evaluated (n=90). The most commonly found cheeses in the retail points were Chihuahua (60%) and Ranchero (28.8%). According to Mexican standards, three SM, two CGS, and none of the ST cheeses complied with the regulations. Two cheeses (cheddar and Ranchero) from SM (2.22%) were positive for L. monocytogenes. Eight cheeses (8.88%) were positive for Salmonella spp. (5 from ST and 3 from CGS). E.coli 0157:H7 and Campylobacter jejuni were negative in all samples. On the Ranchero cheese, total coliforms (TC), faecal coliforms (FC), and yeast and moulds (Y&M) showed no significant differences (P > 0.05) among retail points. Nevertheless, in Chihuahua cheese, the numbers of total coliforms, faecal coliforms, and yeast and moulds were statistically different (P < 0.05) among retail points. PSM Chihuahua cheese had the lowest numbers of total (0.99 ± 1.0 Log 10 CFU/g) and faecal coliforms (166 ± 154 Log 10 CFU/g). CGS cheeses had the lowest counts in terms of yeast and moulds (3.1 ± 2.2 Log 10 CFU/g). The results revealed that most cheeses, regardless of the retail point, did not conform to Mexican standards. The number of total and faecal coliforms indicates either flaws during the production and commercialization processes or the ill-handling of raw materials.
Brazilian Journal of Microbiology, 2013
The ripening process of Serro Minas cheese, one of the most popular cheeses produced with raw milk in Brazil, was studied over the course of 60 days of ripening during dry and rainy seasons. Brazilian legislation prohibits the production of cheese from raw milk unless it was submitted to a maturation period greater than 60 days. However Minas Serro cheese is sold within a few days of ripening. A total of 100 samples of Serro cheese were obtained from five farms; 50 samples were collected during the dry season (winter in Brazil) and 50 samples were collected during the rainy season (summer in Brazil). From each farm, ten cheeses were collected during each season after two days of ripening. Our results showed high levels of total and fecal coliforms at the beginning of the ripening period (approximately 4 Log MPN/g with 3 days of ripening) that decreased with 60 days of ripening reaching almost 1.5 Log MPN/g. Contamination by coagulase-positive staphylococci was reduced by the end of the ripening period. Salmonella spp. was not detected. The staphylococcal enterotoxins B and C were detected in 1% and 4% of the cheeses, respectively, after 30 days of ripening. These results suggest that the ripening process was not effective in eliminating staphylococcal enterotoxins from the cheese. However, none of the investigated strains of Staphylococcus spp. isolated from Serro cheese produced enterotoxins A, B, C or D. The high pathogen and coliform levels at the beginning of the ripening process for the cheese produced during both seasons indicate the need for improvement of the sanitation of the manufacturing conditions.
Czech Journal of Food Sciences, 2009
The aim of this study was to monitor S. aureus growth and toxin production in soft cheese during the technological processing. In model experiments, raw milk was inoculated separately with five S. aureus strains isolated from milk and milk products. All the strains were producers of staphylococcal enterotoxins (SEs) of types A, B, or C. SEs were detected by the enzyme-linked fluorescence assay (ELFA) performed in the MiniVIDAS device. This study has shown that the amount of SEs varied with the tested strains and stages of the technological process. SEs were detected in soft cheese made from pasteurised milk inoculated with 2.9 × 10 5 CFU/g of S. aureus. The prevention of S. aureus contamination and multiplication during the cheese making process is a prerequisite for the production of safe soft cheese. The most important enterotoxin dose build-up factor can be overcome by strict compliance with the cooling requirements during the manufacture, distribution and storage of the product.
Journal of Food Safety, 2018
The aim of this study was to assess the microbiological quality and safety of some cheeses produced in Apulia region, Southern Italy, and classified as "traditional agri-food products." A total of 120 samples were collected and analyzed. From results, 82.5% of cheeses analyzed, had a satisfactory microbiological quality according to the European legislation. The coagulase positive Staphylococci (CPS) count was above the limits set by the European legislation in 17.5% of the samples analyzed. Within the 20 strains of Staphylococcus aureus (S. aureus) isolated, 12 were positive for the detection of the enterotoxin genes. Furthermore, nine strains of S. aureus were positive to reverse passive latex agglutination (SET-RPLA) assay. One of the two samples of Cacioricotta di Vacca Fresco, with a CPS load of 3.02 × 10 5 cfu/g, showed unsatisfactory microbiological safety because was positive to SET-RPLA. Based on the findings, it is essential to apply and maintain good hygiene practices throughout the food chain, especially for traditional agri-food products, which are often produced in small family processing plants using production protocols based on the experience handed down from father to son. Practical applications The traditional agri-food products are foodstuffs much appreciated by consumers because of their organoleptic qualities and taste that brings back to the genuine flavors of the past. However, the hygienic quality and safety of these products is linked to the personal experience of food business operator and not to the regular checking of microbiological parameters that validate the acceptability of foodstuffs and their manufacturing, handling and distribution processes. The results of this study can contribute to the risk analysis for these particular products, and underline the need to apply and maintain good hygiene practices throughout the production chain.