Prevalence and Phylogenetic Characterization of Escherichia coli and Hygiene Indicator Bacteria Isolated from Leafy Green Produce, Beef, and Pork Obtained from Farmers' Markets in Pennsylvania

2017 ◽  
Vol 80 (2) ◽  
pp. 237-244 ◽  
Author(s):  
Joshua A. Scheinberg ◽  
Edward G. Dudley ◽  
Jonathan Campbell ◽  
Beth Roberts ◽  
Michael DiMarzio ◽  
...  

ABSTRACT The popularity of farmers' markets in the United States has led to over 8,400 farmers' markets being in operation in 2015. As farmers' markets have increased in size and complexity in the kinds of foods sold at these venues, so have the potential food safety risks. Since 2008, seven major foodborne illness outbreaks and two recalls associated with food products from farmers' markets have occurred, causing 80 known reported illnesses and one death. Various researchers also have observed vendors performing high-risk food safety retail behaviors, and others have identified microbiological hazards in foods sold at farmers' markets. In this study, the presence of hygiene indicators (coliforms, fecal coliforms, Listeria spp., and Escherichia coli) was assessed in select samples of leafy green produce and meat obtained from farmers' markets in Pennsylvania. E. coli isolates were further characterized by phylogenetic profile and virulence potential. E. coli was present in 40% (20 of 50) and 18% (9 of 50) of beef and pork samples, respectively, and in 28% (15 of 54), 29% (15 of 52), and 17% (8 of 46) of kale, lettuce, and spinach samples, respectively. Listeria spp. was found in 8% (4 of 50) of beef samples, 2% (1 of 54) of kale samples, 4% (2 of 52) of lettuce samples, and 7% (3 of 46) of spinach samples. Among the 10 Listeria spp. isolates, 3 were identified as L. monocytogenes. E. coli isolated from meat samples mainly clustered into phylogroup B1 (66%; 19 of 29), whereas produce isolates clustered into phylogroups B2 (36%; 14 of 39) and B1 (33%; 13 of 39). These E. coli isolates possessed the fimH, iroN, hlyD, and eae genes associated with extraintestinal pathogenic E. coli and Shiga toxin–producing E. coli. The high prevalence but low levels of E. coli and Listeria spp. found on both produce and meat products obtained from farmers' markets in this study strongly indicate that farmers' market vendors would benefit greatly from food safety training and increased public health oversight.

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1543 ◽  
Author(s):  
Issmat I. Kassem ◽  
Nivin A Nasser ◽  
Joanna Salibi

Meat is an important source of high biological value proteins as well as many vitamins and minerals. In Lebanon, beef meats, including raw minced beef, are among the most consumed of the meat products. However, minced beef meat can also be an important source of foodborne illnesses. This is of a major concern, because food safety in Lebanon suffers from well-documented challenges. Consequently, the prevalence and loads of fecal coliforms and Escherichia coli were quantified to assess the microbiological acceptability of minced beef meat in Lebanon. Additionally, antibiotic resistance phenotypes of the E. coli were determined in response to concerns about the emergence of resistance in food matrices in Lebanon. A total of 50 meat samples and 120 E. coli isolates were analyzed. Results showed that 98% and 76% of meat samples harbored fecal coliforms and E. coli above the microbial acceptance level, respectively. All E. coli were resistant to at least one antibiotic, while 35% of the isolates were multidrug-resistant (MDR). The results suggest that Lebanon needs to (1) update food safety systems to track and reduce the levels of potential contamination in important foods and (2) implement programs to control the proliferation of antimicrobial resistance in food systems.


2003 ◽  
Vol 228 (4) ◽  
pp. 331-332 ◽  
Author(s):  
Hussein S. Hussein ◽  
Stanley T. Omaye

Verotoxin-producing Escherichia coli (VTEC) have emerged in the past two decades as food-borne pathogens that can cause major outbreaks of human illnesses worldwide. The number of outbreaks has increased in recent years due to changes in food production and processing systems, eating habits, microbial adaptation, and methods of VTEC transmission. The human illnesses range from mild diarrhea to hemolytic uremic syndrome (HUS) that can lead to death. The VTEC outbreaks have been attributed to O157:H7 and non-O157:H7 serotypes of E. coli. These E. coli serotypes include motile (e.g., O26:H11 and O104:H21) and nonmotile (e.g., O111:H–,0145:H–, and O157:H–) strains. In the United States, E. coli O157:H7 has been the major cause of VTEC outbreaks. Worldwide, however, non-O157:H7 VTEC (e.g., members of the 026, O103, O111, O118, O145, and O166 serogroups) have caused approximately 30% of the HUS cases in the past decade. Because large numbers of the VTEC outbreaks have been attributed to consumption of ruminant products (e.g., ground beef), cattle and sheep are considered reservoirs of these food-borne pathogens. Because of the food safety concern of VTEC, a global perspective on this problem is addressed (Exp Biol Med Vol. 228, No. 4). The first objective was to evaluate the known non-O157:H7 VTEC strains and the limitations associated with their detection and characterization. The second objective was to identify the VTEC serotypes associated with outbreaks of human illnesses and to provide critical evaluation of their virulence. The third objective was to determine the rumen effect on survival of E. coli O157:H7 as a VTEC model. The fourth objective was to explore the role of intimins in promoting attaching and effacing lesions in humans. Finally, the ability of VTEC to cause persistent infections in cattle was evaluated.


2017 ◽  
Vol 83 (6) ◽  
Author(s):  
James R. Johnson ◽  
Stephen B. Porter ◽  
Brian Johnston ◽  
Paul Thuras ◽  
Sarah Clock ◽  
...  

ABSTRACT Chicken meat products are hypothesized to be vehicles for transmitting antimicrobial-resistant and extraintestinal pathogenic Escherichia coli (ExPEC) to consumers. To reassess this hypothesis in the current era of heightened concerns about antimicrobial use in food animals, we analyzed 175 chicken-source E. coli isolates from a 2013 Consumer Reports national survey. Isolates were screened by PCR for ExPEC-defining virulence genes. The 25 ExPEC isolates (12% of 175) and a 2:1 randomly selected set of 50 non-ExPEC isolates were assessed for their phylogenetic/clonal backgrounds and virulence genotypes for comparison with their resistance profiles and the claims on the retail packaging label (“organic,” “no antibiotics,” and “natural”). Compared with the findings for non-ExPEC isolates, the group of ExPEC isolates had a higher prevalence of phylogroup B2 isolates (44% versus 4%; P < 0.001) and a lower prevalence of phylogroup A isolates (4% versus 30%; P = 0.001), a higher prevalence of multiple individual virulence genes, higher virulence scores (median, 11 [range, 4 to 16] versus 8 [range, 1 to 14]; P = 0.001), and higher resistance scores (median, 4 [range, 0 to 8] versus 3 [range, 0 to 10]; P < 0.001). All five isolates of sequence type 131 (ST131) were ExPEC (P = 0.003), were as extensively resistant as the other isolates tested, and had higher virulence scores than the other isolates tested (median, 12 [range, 11 to 13] versus 8 [range, 1 to 16]; P = 0.005). Organic labeling predicted lower resistance scores (median, 2 [range, 0 to 3] versus 4 [range, 0 to 10]; P = 0.008) but no difference in ExPEC status or virulence scores. These findings document a persisting reservoir of extensively antimicrobial-resistant ExPEC isolates, including isolates from ST131, in retail chicken products in the United States, suggesting a potential public health threat. IMPORTANCE We found that among Escherichia coli isolates from retail chicken meat products purchased across the United States in 2013 (many of these isolates being extensively antibiotic resistant), a minority had genetic profiles suggesting an ability to cause extraintestinal infections in humans, such as urinary tract infection, implying a risk of foodborne disease. Although isolates from products labeled “organic” were less extensively antibiotic resistant than other isolates, they did not appear to be less virulent. These findings suggest that retail chicken products in the United States, even if they are labeled “organic,” pose a potential health threat to consumers because they are contaminated with extensively antibiotic-resistant and, presumably, virulent E. coli isolates.


2008 ◽  
Vol 71 (10) ◽  
pp. 2082-2086 ◽  
Author(s):  
LUCIANO BENEDUCE ◽  
GIUSEPPE SPANO ◽  
ARI Q. NABI ◽  
FRANCESCO LAMACCHIA ◽  
SALVATORE MASSA ◽  
...  

In this study, 100 raw meat samples were collected from 15 local Moroccan butcheries in five different areas of the city of Rabat during a period of 4 months. Overall, 7 of 15 butcheries from three areas of the city yielded strains of Escherichia coli O157. Single isolates from 9 (9%) of 100 raw meat samples were biochemically and serologically confirmed as E. coli O157. Using molecular techniques, two strains were positive for the Shiga toxin, with two additional strains containing an attaching-effacing gene. All potentially virulent serotypes isolated from these meat samples showed distinct pulsed-field gel electrophoresis profiles. Based on antibiotic susceptibility testing, more than 70% of the isolates were resistant to ampicillin and clavulanic acid–amoxicillin. Moreover, one strain was resistant to more than three antibiotics. Our study represents the first survey of E. coli O157 and related serotypes in raw meat products in Morocco.


Author(s):  
Özgür Çadırcı ◽  
Ali Gücükoğlu ◽  
Göknur Terzi Güzel ◽  
Tolga Uyanık ◽  
Abdulaziz Abdulahi ◽  
...  

Shiga-like toxin producing Escherichia coli is still an important public issue which causes extremely dangerous health problems. This study was planned in order to examine the inhibitory effect of Modified Atmosphere Packaging application on E. coli O157 and O157: H7. The purposes of the present study were to detect E. coli O157 and O157: H7 strains from ground and cubed beef. A total of 100 MAP cattle meat products (50 minced meat, 50 meat cubes) were collected from the markets and butchers in Samsun province between May and October 2013. According to results, 1(1/50-2%) E. coli O157 and 1(1/50-2%) E. coli O157: H7 strains isolated from 50 ground beef samples, while 1 (1/50-2%) E. coli O157 strain was identified from 50 cubed beef samples. It was determined that E. coli O157 isolate obtained from the MAP ground beef carried stx1, stx2 genes; E. coli O157: H7 isolate carried stx1, stx2, eaeA and hylA genes while E. coli O157 isolate obtained from the MAP cubed meat only carried the stx2 gene. In antibiogram test, both E. coli O157 isolates were resistant to streptomycin and one E. coli O157: H7 isolate was resistant to streptomycin, cephalothin and tetracycline. As a consequence; in order to protect public health, products should be kept in proper hygienic and technical conditions during sale and storage and use of uncontrolled antibiotics should be avoided.


2020 ◽  
Vol 86 (20) ◽  
Author(s):  
Sultana Solaiman ◽  
Sarah M. Allard ◽  
Mary Theresa Callahan ◽  
Chengsheng Jiang ◽  
Eric Handy ◽  
...  

ABSTRACT As climate change continues to stress freshwater resources, we have a pressing need to identify alternative (nontraditional) sources of microbially safe water for irrigation of fresh produce. This study is part of the center CONSERVE, which aims to facilitate the adoption of adequate agricultural water sources. A 26-month longitudinal study was conducted at 11 sites to assess the prevalence of bacteria indicating water quality, fecal contamination, and crop contamination risk (Escherichia coli, total coliforms [TC], Enterococcus, and Aeromonas). Sites included nontidal freshwater rivers/creeks (NF), a tidal brackish river (TB), irrigation ponds (PW), and reclaimed water sites (RW). Water samples were filtered for bacterial quantification. E. coli, TC, enterococci (∼86%, 98%, and 90% positive, respectively; n = 333), and Aeromonas (∼98% positive; n = 133) were widespread in water samples tested. Highest E. coli counts were in rivers, TC counts in TB, and enterococci in rivers and ponds (P < 0.001 in all cases) compared to other water types. Aeromonas counts were consistent across sites. Seasonal dynamics were detected in NF and PW samples only. E. coli counts were higher in the vegetable crop-growing (May-October) than nongrowing (November-April) season in all water types (P < 0.05). Only one RW and both PW sites met the U.S. Food Safety Modernization Act water standards. However, implementation of recommended mitigation measures of allowing time for microbial die-off between irrigation and harvest would bring all other sites into compliance within 2 days. This study provides comprehensive microbial data on alternative irrigation water and serves as an important resource for food safety planning and policy setting. IMPORTANCE Increasing demands for fresh fruit and vegetables, a variable climate affecting agricultural water availability, and microbial food safety goals are pressing the need to identify new, safe, alternative sources of irrigation water. Our study generated microbial data collected over a 2-year period from potential sources of irrigation (rivers, ponds, and reclaimed water sites). Pond water was found to comply with Food Safety Modernization Act (FSMA) microbial standards for irrigation of fruit and vegetables. Bacterial counts in reclaimed water, a resource that is not universally allowed on fresh produce in the United States, generally met microbial standards or needed minimal mitigation. We detected the most seasonality and the highest microbial loads in river water, which emerged as the water type that would require the most mitigation to be compliant with established FSMA standards. This data set represents one of the most comprehensive, longitudinal analyses of alternative irrigation water sources in the United States.


Author(s):  
Than Ton That Nhuan ◽  
Tuyet Mai Ngo Thi ◽  
Ngoc Lan Pham Thi ◽  
◽  
◽  
...  

Processed meat products are commonplace foods that are becoming increasingly popular in consumers' daily diets. Therefore, it is highly essential to assess the extent of microbiological contamination in the samples of processed meat products from markets in a bid to provide updated data of microbiological contamination to relevant agencies and local consumers as part of the current state of food safety and hygiene in the locality. A survey on microbiological contamination of processed meat products was conducted on samples collected from some markets in Southern Hue city. The 90 samples of three groups of fermented meat, packaged and non-packaged meat were analyzed. The results showed that, 100% of the samples were contaminated with aerobic microorganisms, Coliforms and Escherichia coli, in which 100% of the samples of Coliforms and E. coli did not meet the quality norms set by the Ministry of Health. The total aerobic microorganisms, Coliforms and E. coli ranged from 2.7 &times; 103 to 2.8 &times; 109 CFU/g, 1.1 &times; 104 to 1.5 &times; 108 MPN/g and 1.1 &times; 102 to 9.2 &times; 105 MPN/g, respectively. No presence of Clostridium perfringens or Staphylococcus aureus was detected in the examined samples.


2004 ◽  
Vol 67 (6) ◽  
pp. 1234-1237 ◽  
Author(s):  
N. BENKERROUM ◽  
Y. BOUHLAL ◽  
A. EL ATTAR ◽  
A. MARHABEN

Samples of meat and dairy products taken from the city of Rabat, Morocco, were examined for the presence of Escherichia coli O157 by the selective enrichment procedure followed by plating on cefixime–tellurite–sorbitol MacConkey agar and a latex agglutination test. The ability of isolates to produce Shiga toxins (ST1 or ST2) was also tested by an agglutination test using sensitized latex. Dairy samples (n = 44) included different products commonly consumed in the country. Meat samples (n = 36) were taken from traditional butchers because these products are generally marketed in this way. Random samples were taken from each product during the period of January through May. Of the 80 samples tested, 8 (10%) harbored E. coli O157. Four dairy and four meat samples were contaminated (9.1 and 11.1%, respectively). Of 10 E. coli O157 isolates from contaminated samples demonstrating true antigen-antibody agglutination, 5 (50%) produced either ST2 alone or ST2 plus ST1. Four of the five strains (80%) were meat isolates and produced ST2 with or without ST1, and the fifth was a dairy isolate producing ST2.


Author(s):  
Joshua Nazareth ◽  
Angela Shaw ◽  
Kathleen Delate ◽  
Robert Turnbull

Abstract Availability of organic foods has been increasing in the United States due to consumer demand for food produced with a lower environmental footprint. Surveys show that organic consumers view organic food as safer and of higher quality, but a number of food-borne outbreaks have been linked to organic produce in recent years. This outcome suggests that improved food safety protocols are needed to ensure food safety along organic food chains. In this study, model integrated crop–livestock organic systems were established in three states (Iowa, Minnesota and Pennsylvania) to evaluate biological performance and food safety aspects. Organically raised cattle and their feed/forage, feces, hide and meat were examined for the presence of two pathogens, Escherichia coli O157:H7 and Salmonella spp. Results confirmed that E. coli O157:H7 was not isolated on any hide or meat samples. Across all sites, the prevalence rate for E. coli O157:H7 on feed/forage and fecal matter was 9.43 and 7.26%, respectively. Salmonella spp. was isolated from 1.89, 3.33 and 18.6% of feed, fecal and hide samples, respectively. Salmonella spp. was not detected on any meat samples. While Salmonella spp. rates on hides were greater than those in feed and fecal samples, the prevalence rate of both pathogens on cattle hides was lower than in previous studies. The use of an organic fly repellent containing essential oils in this study would need to be investigated further to determine any correlation between its use and lower pathogen rates on hides. Feed/forage was more likely to test positive for E. coli O157:H7 from June through August, indicating the importance of strict sanitary measures to prevent feed contamination during summer months. These results suggest that careful adherence to food safety management strategies can help reduce the risk of bacterial contamination in integrated crop–livestock systems.


1994 ◽  
Vol 57 (8) ◽  
pp. 734-736 ◽  
Author(s):  
ALOYSIO M. F. CERQUEIRA ◽  
ANITA TIBANA ◽  
TANIA A. T. GOMES ◽  
BEATRIZ E. C. GUTH

A total of 1,066 Escherichia coli colonies isolated from 105 raw bovine meat samples purchased at supermarkets in Rio de Janeiro were submitted to hybridization assays with gene probes for LT-II and STb enterotoxins. Five colonies comprising four different E. coli strains isolated from four pieces of beef, two samples of ground beef (5.7%) and two hamburger patties (5.7%) hybridized with the LT-II probe, while no hybridization occurred with the STb probe. Expression of LT-II enterotoxin using the Y1 adrenal cell assay was verified in two of four E. coli strains. A serotype diversity existed among LT-II E. coli strains.


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