Multistate Outbreak of Escherichia coli O157:H7 Infections Associated with In-Store Sampling of an Aged Raw-Milk Gouda Cheese, 2010†

2012 ◽  
Vol 75 (10) ◽  
pp. 1759-1765 ◽  
Author(s):  
J. T. McCOLLUM ◽  
N. J. WILLIAMS ◽  
S. W. BEAM ◽  
S. COSGROVE ◽  
P. J. ETTESTAD ◽  
...  

In 2010, 41 patients ill with Escherichia coli O157:H7 isolates determined to be indistinguishable by pulsed-field gel electrophoresis were identified among residents of five Southwestern U.S. states. A majority of patients reported consuming complimentary samples of aged raw-milk Gouda cheese at national warehouse chain store locations; sampling Gouda cheese was significantly associated with illness (odds ratio, 9.0; 95% confidence interval, 1.7 to 47). Several Gouda samples yielded the O157:H7 outbreak strain, confirming the food vehicle and source of infections. Implicated retail food-sampling operations were inconsistently regulated among affected states, and sanitation deficiencies were common among sampling venues. Inspection of the cheese manufacturer indicated deficient sanitation practices and insufficient cheese curing times. Policymakers should continue to reexamine the adequacy and enforcement of existing rules intended to ensure the safety of raw-milk cheeses and retail food sampling. Additional research is necessary to clarify the food safety hazards posed to patrons who consume free food samples while shopping.

1998 ◽  
Vol 61 (7) ◽  
pp. 917-920 ◽  
Author(s):  
C. VERNOZY-ROZAND ◽  
C. MAZUY ◽  
S. RAY-GUENIOT ◽  
S. BOUTRAND-LOEÏ ◽  
A. MEYRAND ◽  
...  

An automated enzyme-linked fluorescence immunoassay (ELFA), the VIDAS E. coli O157 method, was compared with immunomagnetic separation (IMS) followed by culture on cefixime tellurite sorbitol MacConkey agar (CT-SMAC) for detecting Escherichia coli O157 in artificially and naturally contaminated food samples including raw milk cheeses, poultry, raw sausages, and ground beef retail samples. Confirmation of the samples positive according to the ELFA was performed by use of an automated immunoconcentration system, VIDAS ICE, which allows selective capture and release of target organisms. A total of 496 retail food samples were examined. Seventeen food samples gave positive values with the ELFA method, and among them 9 food samples were confirmed by the ICE method. Eight were shown to contain sorbitol-positive, O157-positive, H7-negative, motile, non-verotoxin-producing E. coli. The ninth positive sample contained an O157-positive, H7-negative, sorbitol-negative, non-verotoxin-producing E. coli. The IMS technique only allowed confirmation of this sorbitol-negative, non-verotoxin-producing E. coli O157.


2015 ◽  
Vol 78 (9) ◽  
pp. 1733-1737 ◽  
Author(s):  
ALEXANDER GILL ◽  
DENISE OUDIT

In this article, we discuss the enumerative analysis for Escherichia coli O157 in two raw milk Gouda cheese products (A and B), implicated in an outbreak of 29 cases of E. coli O157:H7 illness that occurred across Canada in 2013. Samples were enumerated for E. coli O157 by most probable number (MPN) over a period of 30 to 60 days after the end of the outbreak. Samples (55.55 g) of product A (n = 14) were analyzed at 146 to 180 days postproduction. E. coli O157 was isolated from six samples at 19.9 to 44.6 MPN/kg. The E. coli O157 concentration of product A estimated from the results of all 14 samples was 9.5 MPN/kg. Samples (55.55 g) of product B (n = 20) were analyzed at 133 to 149 days postproduction. E. coli O157 was isolated from four samples at 19.9 MPN/kg. The E. coli O157 concentration of product B estimated from the results of all 20 samples was 3.7 MPN/kg. Analysis of a 305-g sample of product A (n = 1) stored at 4°C until 306 days postproduction revealed that the E. coli O157 concentration had declined to 3.6 MPN/kg. E. coli O157 could not be isolated from 555-g samples of product B (n = 5) after 280 days postproduction. The physicochemical parameters (pH, water activity, percent moisture, and percent salt) of both cheese products were found to be in the normal range for this type of product. The results of this study demonstrate that E. coli O157 could not replicate during storage at 4°C in the products tested but was capable of survival following aging and prolonged storage. This indicates that, if contaminated, the minimum 60-day aging period, which is required for raw milk Gouda cheeses, is not sufficient in all cases to ensure that the product does not contain viable cells of E. coli O157. The results also indicate that samples sizes greater than 100 g may be required to reliably detect E. coli O157 in cheese products associated with outbreaks.


2006 ◽  
Vol 69 (2) ◽  
pp. 441-443 ◽  
Author(s):  
M. SAMADPOUR ◽  
M. W. BARBOUR ◽  
T. NGUYEN ◽  
T.-M. CAO ◽  
F. BUCK ◽  
...  

The objective of this study was to determine the prevalence of enterohemorrhagic Escherichia coli (EHEC), E. coli O157, Salmonella, and Listeria monocytogenes in retail food samples from Seattle, Wash. A total of 2,050 samples of ground beef (1,750 samples), mushrooms (100 samples), and sprouts (200 samples) were collected over a 12-month period and analyzed for the presence of these pathogens. PCR assays, followed by culture confirmation were used to determine the presence or absence of each organism. Of the 1,750 ground beef samples analyzed, 61 (3.5%) were positive for EHEC, and 20 (1.1%) of these were positive for E. coli O157. Salmonella was present in 67 (3.8%) of the 1,750 ground beef samples. Of 512 ground beef samples analyzed, 18 (3.5%) were positive for L. monocytogenes. EHEC was found in 12 (6.0%) of the 200 sprout samples, and 3 (1.5%) of these yielded E. coli O157. Of the 200 total sprout samples, 14 (7.0%) were positive for Salmonella and none were positive for L. monocytogenes. Among the 100 mushroom samples, 4 (4.0%) were positive for EHEC but none of these 4 samples were positive for E. coli O157. Salmonella was detected in 5 (5.0%) of the mushroom samples, and L. monocytogenes was found in 1 (1.0%) of the samples.


2017 ◽  
Vol 81 (2) ◽  
pp. 325-331 ◽  
Author(s):  
Andrea Currie ◽  
Eleni Galanis ◽  
Pedro A. Chacon ◽  
Regan Murray ◽  
Lynn Wilcott ◽  
...  

ABSTRACT Between 12 July and 29 September 2013, 29 individuals in five Canadian provinces became ill following infection with the same strain of Escherichia coli O157:H7 as defined by molecular typing results. Five case patients were hospitalized, and one died. Twenty-six case patients (90%) reported eating Gouda cheese originating from a dairy plant in British Columbia. All of the 22 case patients with sufficient product details available reported consuming Gouda cheese made with raw milk; this cheese had been produced between March and July 2013 and was aged for a minimum of 60 days. The outbreak strain was isolated from the implicated Gouda cheese, including one core sample obtained from an intact cheese wheel 83 days after production. The findings indicate that raw milk was the primary source of the E. coli O157:H7, which persisted through production and the minimum 60-day aging period. This outbreak is the third caused by E. coli O157:H7 traced to Gouda cheese made with raw milk in North America. These findings provide further evidence that a 60-day ripening period cannot ensure die-off of pathogens that might be present in raw milk Gouda cheese after production and have triggered an evaluation of processing conditions, physicochemical parameters, and options to mitigate the risk of E. coli O157:H7 infection associated with raw milk Gouda cheese produced in Canada.


1994 ◽  
Vol 57 (10) ◽  
pp. 859-864 ◽  
Author(s):  
MELISSA L. CALICCHIA ◽  
JANICE D. REGER ◽  
CONNIE I. N. WANG ◽  
DARYL W. OSATO

Enumeration of Escherichia coli O157:H7 from Petrifilm™ E. coli (PEC) Count plates was studied incorporating the Petrifilm™ -HEC kit without sample pre-enrichment. Samples containing various E. coli O157:H7 inoculum levels were plated according to PEC package insert instructions. Plates were incubated at 32°C for dairy products and at 35°C for other samples. Total coliform, E. coli and E. coli O157:H7 levels were quantified in both control and inoculated samples. The average recovery from various food matrices was 74.8%. Food samples included retail soft cheese, clams, ground beef, chicken, salad mix, apple juice, cantaloupe and raw milk. The overall recovery was also determined on surface samples including cutting boards and preparation tables, at 116.3%. Results suggest that enumeration of E. coli O157:H7 from PEC Count plates is possible for products containing background coliforms as high as 40,000 colony forming units (CFU)/g, and with minimal background coliforms at <10 CFU/g. This method is a fast and efficient means of quantifying levels of presumptive positive E. coli O157:H7 from PEC Count plates.


Food Control ◽  
2004 ◽  
Vol 15 (6) ◽  
pp. 453-456 ◽  
Author(s):  
Ö Öksüz ◽  
M Arici ◽  
S Kurultay ◽  
T Gümüs

1999 ◽  
Vol 122 (2) ◽  
pp. 337-341 ◽  
Author(s):  
M. AKIBA ◽  
T. MASUDA ◽  
T. SAMESHIMA ◽  
K. KATSUDA ◽  
M. NAKAZAWA

A total of 77 Escherichia coli O157[ratio ]H7 (H−) isolates from cattle in Japan were investigated by molecular biological methods. Most of these isolates (43 isolates) possessed the stx2 gene, but not stx1. Fifteen bacteriophage types and 50 pulsed-field gel electrophoresis (PFGE) profiles were observed. One isolate was indistinguishable from the human outbreak strain by these methods. This indicates that cattle must be considered as a possible source of human E. coli O157[ratio ]H7 infection in Japan.


2009 ◽  
Vol 72 (10) ◽  
pp. 2065-2070 ◽  
Author(s):  
MASASHI KANKI ◽  
KAZUKO SETO ◽  
JUNKO SAKATA ◽  
TETSUYA HARADA ◽  
YUKO KUMEDA

Universal preenrichment broth (UPB) was compared with modified Escherichia coli broth with novobiocin (mEC+n) for enrichment of Shiga toxin–producing E. coli O157 and O26, and with buffered peptone water (BPW) for preenrichment of Salmonella enterica. Ten strains each of the three pathogens were inoculated into beef and radish sprouts following thermal, freezing, or no treatment. With regard to O157 and O26, UPB incubated at 42°C recovered significantly more cells from inoculated beef than UPB at 35°C and from radish sprout samples than UPB at 35°C and mEC+n. With regard to Salmonella, UPB incubated at 42°C was as effective as UPB at 35°C and BPW at recovering cells from beef and radish sprout samples. No significant difference was noted between the effectiveness of UPB at 42°C and UPB at 35°C or BPW in the recovery of Salmonella from 205 naturally contaminated poultry samples. By using UPB at 42°C, one O157:H7 strain was isolated from the mixed offal of 53 beef samples, 6 cattle offal samples, and 50 pork samples all contaminated naturally, with no pathogen inoculation. The present study found that UPB incubated at 42°C was as effective as, or better than, mEC+n for enrichment of O157 and O26 and comparable to BPW for preenrichment of Salmonella. These findings suggest that a great deal of labor, time, samples, and space may be saved if O157, O26, and Salmonella are enriched simultaneously with UPB at 42°C.


2010 ◽  
Vol 73 (12) ◽  
pp. 2217-2224 ◽  
Author(s):  
DENNIS J. D'AMICO ◽  
MARC J. DRUART ◽  
CATHERINE W. DONNELLY

This study was conducted to examine the fate of Escherichia coli O157:H7 during the manufacture and aging of Gouda and stirred-curd Cheddar cheeses made from raw milk. Cheeses were manufactured from unpasteurized milk experimentally contaminated with one of three strains of E. coli O157:H7 at an approximate population level of 20 CFU/ml. Samples of milk, whey, curd, and cheese were collected for enumeration of bacteria throughout the manufacturing and aging process. Overall, bacterial counts in both cheese types increased almost 10-fold from initial inoculation levels in milk to approximately 145 CFU/g found in cheeses on day 1. From this point, counts dropped significantly over 60 days to mean levels of 25 and 5 CFU/g in Cheddar and Gouda, respectively. Levels of E. coli O157:H7 fell and stayed below 5 CFU/g after an average of 94 and 108 days in Gouda and Cheddar, respectively, yet remained detectable after selective enrichment for more than 270 days in both cheese types. Changes in pathogen levels observed throughout manufacture and aging did not significantly differ by cheese type. In agreement with results of previous studies, our results suggest that the 60-day aging requirement alone is insufficient to completely eliminate levels of viable E. coli O157:H7 in Gouda or stirred-curd Cheddar cheese manufactured from raw milk contaminated with low levels of this pathogen.


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