ABSTRACT Properly executed hand washing by food service employees can greatly minimize the risk of transmitting foodborne pathogens to food and food contact surfaces in restaurants. However, food service employee hand washing is often not done correctly or does not occur as often as it should. The purpose of this study was to assess the relative impact of (i) the convenience and accessibility of hand washing facilities; (ii) the maintenance of hand washing supplies, (iii) multiunit status, (iv) having a certified food protection manager, and (v) having a food safety management system for compliance with proper hand washing. Results revealed marked differences in hand washing behaviors between fast-food and full-service restaurants; 45% of 425 fast-food restaurants and 57% of 396 full-service restaurants were out of compliance for washing hands correctly, and 57% of fast-food restaurants and 78% of full-service restaurants were out of compliance for employee hands being washed when required. Logistic regression results indicated the benefits of accessibility and maintenance of the hand washing sink and of a food safety management system for increasing the likelihood of employees washing hands when they are supposed to and washing them correctly when they do. HIGHLIGHTS Most restaurant employees do not wash their hands correctly or when they should. Large differences in hand washing were found between fast-food and full-service restaurants. Food safety management systems are recommended for hand washing compliance.

This study was intended to characterize the perceived risks of urban agriculture by residents of four low-income neighborhoods in which the potential exists for further urban agriculture development and to provide data to support whether any chemical hazards and foodborne pathogens as potential food safety hazards were present. Sixty-seven residents participated in focus groups related to environmental health, food security, and urban gardening. In addition, soils from six locations were tested. Residents expressed interest in the development of urban gardens to improve access to healthy, fresh produce, but they had concerns about soil quality. Soils were contaminated with lead (Pb), zinc, cadmium (Cd), and copper, but not arsenic or chromium. Results from our study suggest paint was the main source of soil contamination. Detectable polyaromatic hydrocarbon (PAH) levels in urban soils were well below levels of concern. These urban soils will require further management to reduce Pb and possibly Cd bioavailability to decrease the potential for uptake into food crops. Although the number of locations in this study is limited, results suggest lower levels of soil contaminants at well-established gardens. Soil tillage associated with long-term gardening could have diluted the soil metal contaminants by mixing the contaminants with clean soil. Also, lower PAH levels in long-term gardening could be due to enhanced microbial activity and PAH degradation, dilution, or both due to mixing, similar to metals. No foodborne pathogen targets were detected by PCR from any of the soils. Residents expressed the need for clearness regarding soil quality and gardening practices in their neighborhoods to consume food grown in these urban areas. Results from this study suggest long-term gardening has the potential to reduce soil contaminants and their potential threat to food quality and human health and to improve access to fresh produce in low-income urban communities.

Manure from draft animals deposited in fields during vegetable and fruit production may serve as a potential source of preharvest pathogen contamination of foods. To better quantify this risk, we determined the prevalence of Escherichia coli O157:H7 in horses. Between June and September 2009, freshly voided fecal samples were collected from horses stabled on 242 separate premises in Ohio, USA. Overall, the prevalence of E. coli O157:H7 was 1 of 242 (0.4% prevalence, 95% confidence interval [CI] = 0.01 to 2.28). E. coli O157:H7 was recovered from none of the 107 equine fecal samples (0% prevalence, 95% CI = 0.00 to 3.39) that originated from locations without ruminant presence, and only 1 of the 135 horse fecal samples (0.7% prevalence, 95% CI = 0.02 to 4.06) from sites where ruminants were also present. The lone positive sample was collected from a horse that was costabled with a goat. Subsequent sampling at that location identified indistinguishable subtypes of E. coli O157:H7 present in the cohoused goat, in the environment, insects, sheep, and other goats housed in an adjacent field. E. coli O157:H7 was not isolated from the five subsequent samples from this horse. These data indicate that E. coli O157:H7 carriage by horses is an uncommon event.

Caenorhabditis elegans , a free-living nematode found in soil, has been shown to ingest human enteric pathogens, thereby potentially serving as a vector for preharvest contamination of fruits and vegetables. A study was undertaken to evaluate the efficacy of cleaners and sanitizers in killing Salmonella enterica serotype Newport in the gut of C. elegans . Adult worms were fed nalidixic acid–adapted cells of Escherichia coli OP50 (control) or Salmonella Newport for 24 h, washed, placed on paper discs, and incubated at temperatures of 4 or 20°C and relative humidities of 33 or 98% for 24 h. Two commercial cleaners (Enforce and K Foam Lo) and four sanitizers (2% acetic acid, 2% lactic acid, Sanova, and chlorine [50 and 200 μg/ml]) were applied to worms for 0, 2, or 10 min. Populations of E. coli and Salmonella Newport (CFU per worm) in untreated and treated worms were determined by sonicating worms in 0.1% peptone and surface plating suspensions of released cells on tryptic soy agar containing nalidixic acid. Populations of Salmonella Newport in worms exposed to 33 or 98% relative humidity at 4°C or 33% relative humidity at 20°C were significantly ( P ≤ 0.05) lower than the number surviving exposure to 98% relative humidity at 20°C. In general, treatment of desiccated worms with cleaners and sanitizers was effective in significantly ( P ≤ 0.05) reducing the number of ingested Salmonella Newport. Results indicate that temperature and relative humidity influence the survival of Salmonella Newport in the gut of C. elegans , and cleaners and sanitizers may not eliminate the pathogen.

Local health departments that investigate foodborne disease outbreaks do not have adequate guidelines for collecting data that could be used to estimate dose-response relationships, a key component of hazard characterization in quantitative microbial risk assessment. To meet this need, criteria and a questionnaire template for the collection of appropriate dose-response data in the context of outbreaks were developed and applied in the investigation of a point-source outbreak linked to Salmonella serotype Enteritidis in a salmon entrée in February 2000. In this outbreak, the attack rate and risk of hospitalization increased with the amount of salmon entrée consumed, and detailed data were obtained on illness severity measures and host susceptibility factors. Local health departments might consider broadening investigations to include the collection of additional data when investigating outbreaks that have met a specific set of conditions. These data could provide information needed by federal regulatory agencies and other organizations for quantitative microbial risk assessment. Intensive investigations of outbreaks could prevent future illnesses by providing information needed to develop approaches to minimizing risk.

Caenorhabditis elegans was studied to determine the potential role of free-living microbivorous nematodes as vectors for preharvest contamination of fruits and vegetables with foodborne pathogens. The propensity of C. elegans to be attracted to seven strains of Escherichia coli O157:H7, eight serotypes of Salmonella , six strains of Listeria monocytogenes , and cantaloupe juice was investigated. Twenty to 30 adult worms were placed on the surface of K agar midway between a 24-h bacterial colony and 10 μl of uninoculated tryptic soy broth (TSB) or cantaloupe juice positioned 1.5 cm apart. The numbers of nematodes that migrated to the colony, to the TSB, and to the cantaloupe juice within 5, 10, 15, and 20 min at 21°C were determined, and then the plates were incubated at 37°C for up to 7 days to determine the ability of C. elegans to survive and reproduce in bacterial colonies. The nematode was attracted to colonies of all test pathogens and survived and reproduced within colonies for up to 7 days. C. elegans was not attracted to cantaloupe juice. The potential of C. elegans to serve as a vector for the transport of Salmonella Poona to cantaloupe rinds was investigated. Adult worms that had been immersed in a suspension of Salmonella Poona were deposited 1 or 3 cm below the surface of soil on which a piece of cantaloupe rind was placed. The rind was analyzed for the presence of Salmonella Poona after 1, 3, 7, and 10 days at 21°C. The presence of Salmonella Poona was evident more quickly on rinds positioned on soil beneath which C. elegans inoculated with Salmonella Poona was initially deposited than on rinds positioned on soil beneath which Salmonella Poona alone was deposited. The time required to detect Salmonella Poona on rinds was longer when the rind was placed 3 cm above the inoculum than when the rind was placed 1 cm above the inoculum. Free-living nematodes may play a role in the preharvest dispersal of incidental human pathogens in soil to the surfaces of raw fruits and vegetables in contact with soil during development and maturation, as evidenced by the behavior of C. elegans as a test model.

Free-living nematodes may harbor, protect, and disperse bacteria, including those ingested and passed in viable form in feces. These nematodes are potential vectors for human pathogens and may play a role in foodborne diseases associated with fruits and vegetables eaten raw. In this study, we evaluated the associations between a free-living soil nematode, Caenorhabditis elegans , and Escherichia coli , an avirulent strain of Salmonella Typhimurium, Listeria welshimeri , and Bacillus cereus . On an agar medium, young adult worms quickly moved toward colonies of all four bacteria; over 90% of 3-day-old adult worms entered colonies within 16 min after inoculation. After 48 h, worms moved in and out of colonies of L. welshimeri and B. cereus but remained associated with E. coli and Salmonella Typhimurium colonies for at least 96 h. Young adult worms fed on cells of the four bacteria suspended in K medium. Worms survived and reproduced with the use of nutrients derived from all test bacteria, as determined for eggs laid by second-generation worms after culturing for 96 h. Development was slightly slower for worms fed gram-positive bacteria than for worms fed gram-negative bacteria. Worms that fed for 24 h on bacterial lawns formed on tryptic soy agar dispersed bacteria over a 3-h period when they were transferred to a bacteria-free agar surface. The results of this study suggest that C. elegans and perhaps other free-living nematodes are potential vectors for both gram-positive and gram-negative bacteria, including foodborne pathogens in soil.

Ten essential elements were determined in dry and canned butter beans ( Phaseolus limensis L .) by atomic absorption spectrophotometry. Samples were taken at different stages during the canning process to determine where changes in element content occurred. The content of each sample was compared statistically to other samples taken within the process. Element retention, excluding chloride and sodium, ranged from 51 to 84% on a dry weight basis, and 14 to 24% on wet weight basis.

Ten essential elements were determined in dry and canned chick peas ( Cicer arietinum L .) by atomic absorption spectrophotometry. Samples were taken at different stages during the canning process to determine where changes in element content occurred. The content of each sample was compared statistically to other samples taken within the process. Element retention, excluding chloride and sodium, ranged from 12 to 127% on a dry weight basis and 4 to 45% on wet weight basis.

Ten essential mineral elements were determined in dry and in canned kidney beans ( Phaseolus vulgaris L.). Samples were taken at different stages during the canning process to determine where changes in element content occurred. Canned kidney beans contained significantly lower concentrations of iron, magnesium, manganese, potassium, and zinc than dry kidney beans, on a dry weight basis. These decreases were probably caused by the elements being extracted out during soaking and blanching of the kidney beans and/or during the actual thermal processing where elements were extracted into the can liquid. There was a significant increase in calcium in the canned product and no significant difference in copper and phosphorus contents between the dry and canned products. Chloride and sodium content in canned kidney beans increased due to the sodium chloride content of the filling medium, and their concentrations varied depending on the concentration of the medium used. Retention of all elements, except chloride and sodium, ranged from 61 to 117% on a dry weight basis and from 19 to 36% on wet weight basis, retention being defined as the ratio of content in the canned to that in the dry product as received at the plant.

Vibrio cholerae non-O1 was found throughout the Apalachicola, FL, estuary. V. cholerae O1 was isolated primarily at the City of Apalachicola sewage treatment plant, Scipio Creek and the north shore of St. George Island. Highest concentrations of both serogroups occurred in August and November. Concentrations were lowest in February and increased substantially in May. A cholera toxin-like toxin was not detected in any of the V. cholerae cultures by the Y-1 mouse adrenal cell assay or the enzyme-linked immunosorbent assay (ELISA). However, 35% of the V. cholerae O1 and 22% of the V. cholerae non-O1 cultures selected for testing caused diarrhea in infant rabbits. The proportion of V. cholerae O1 and non-O1 isolates pathogenic to infant rabbits increased as water temperature decreased. Fecal coliforms appeared to be more useful than total coliforms as indicators of the numbers of V. cholerae in water, but neither of those National Shellfish Sanitation Program indicator groups ensured against the presence of pathogenic V. cholerae in shellfish-growing areas.

Content of 16 essential elements was determined in three kinds of frankfurters by atomic absorption spectrophotometry. The element content of frankfurter batter was compared with processed frankfurters. There were larger (P<0.05) amounts of sodium in beef; colbalt, manganese and sodium in chicken; and manganese, potassium and sodium in meat frankfurters (beef and pork) after processing. Chicken samples contained less (P<0.05) chloride and potassium after processing. All frankfurters studied were superior sources of iron and zinc and fair sources of potassium when compared to other foodstuffs. Element retention ranged from 80.9% to over 100%. Data suggest that processing had minimal effects on element loss.