Progress 05/01/15 to 04/30/19
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Undergraduate students were recruited from Nutrition and Food Science, Environmental Science, Urban planning, Psychology, and Biology. Together with graduate students at Nutrition and Food Science, they were trained in soil and vegetable sampling, laboratory analysis, technical presentation, and data analysis. How have the results been disseminated to communities of interest?In addition to publications and conferencepresentations, aField Day was held in October, 2017 at the Campus Student Organic Farm at Oakland University to share research findings with community gardeners. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Soil samples were collected at a depth of 0-7.5 cm. Each soil sample was pooled by five subsamples collected approximately 10 cm from each other at the center and four corners around the same sampling point. Vegetables were consisted of leafy greens and root vegetables based on the availability of different categories in the gardens. The overall prevalence ofE. coliwas lower than that ofEnterococcusspp. in both soil and vegetables (p<0.05). Out of 19 soil samples analyzed, 11 (57.9%) were contaminated withE. coliand 17 (89.5%) were contaminated withEnterococcusspp. The prevalence ofE. coliin vegetables was 47.9% whereasEnterococcusspp. was recovered in 79.2% of vegetable samples.Enterococcusspecies identification revealedE. mundtii,E. casseliflavus,E. durans,E. faecalis,E. faecium, and unidentified species in soil. In contrast, the vast majority ofEnterococcusspp.from vegetables wasE. faecalis, followed byE. faeciumandE. mundtii.Six antibiotics that have been studied in the environment were analyzed on five soil samples collected from four corners and the center of the plot. The antibiotics included azithromycin, ciprofloxacin, erythromycin, oxytetracycline, sulfamethoxazole, and thrimethoprim. The QuEChERS extraction method was used for antibiotic extraction according to the official method of AOAC. Erythromycin, oxytetracycline, sulfamethoxazole were detected in soil samples. The low antibiotic concentrations detected in this study were an indication of little or no influence of external antibiotics on the soils. However, the role of antibiotic residues as regulatory substances and signaling moleculesshould be explored because sub-inhibitory antibiotics may be able to mediate the dissemination of antibiotic resistance, especially as high prevalence of antibiotic resistance is common in the environment.This study collected important baseline data on heavy metals, antibiotics, and microorganisms in urban food production with limited human and animal waste exposure.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
Mafiz, A.I., L.N. Perera, Y. He, W. Zhang, S. Xiao, W. Hao, S. Sun, K. Zhou, and Y. Zhang. Case study on the soil antibiotic resistome in an urban community garden. International Journal of Antimicrobial Agents. 2018, 52: 241-250.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2019
Citation:
Perera, L.P., A.I. Mafiz, N.R. Amarasekara, E. Chang, V.B. K.Rao, and Y. Zhang. Antimicrobial-resistant E. coli and Enterococcus spp. Recovered from Urban Food Production. Submitted.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2017
Citation:
Perera, L.N., A. Mafiz, and Y. Zhang. Prevalence and Antibiotic Resistance of E. coli and Enterococcus in Urban Agriculture. International Association of Food Protection (IAFP) Annual Conference. Tampa, FL, July 2017
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Progress 05/01/16 to 04/30/17
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest? Zhang, Y. Food safety in urban agriculture. Michigan Environmental Health Association (MEHA) Annual Education Conference, Big Rapids, MI, March 2017 Zhang, Y. Food and soil contamination in Southeastern Michigan urban community gardens. IFT annual conference, Chicago, IL, July 2016 What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Urban agriculture concepts and food analysis techniques on bacteria and chemical detection were introduced and integrated into the existing food science courses at WSU and OU, including NFS4150 Advanced Food Science, NFS5140 Laboratory Techniques, NFS6030 Microbial Food Safety at WSU, BIO322 Organic Farming and BIO491 Biology of Food at OU. Two MS students from NFS6030 Microbial Food Safety joined PI Zhang's lab at the end of Fall 2016 for their thesis research on urban agriculture. A current MS student has defended her thesis on microbial contamination in urban agriculture and will join food industry in the summer of 2017. Co-PI Hansen from OU gave a guest lecture at WSU on organic food production and urban farming in NFS4150 Advanced Food Science in March, 2017. Students have gained increased knowledge of physical, chemical, and biological contamination in urban agriculture and risk factors impacting food safety and sustainability associated with urban agriculture. They were also able to integrate their knowledge in data analysis and scientific writing.
Publications
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Progress 05/01/15 to 04/30/16
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?An undergraduate cohort including students from WSU and OU was developed to receive intensive instruction on the scientific principles, technology, operational procedures of the soil and vegetable sampling and laboratory equipment associated with the project, and the downstream analysis of metals, chemicals, and bacteria. Training also included effective interaction with community members and appropriate health and safety measures. Working in interdisciplinary teams of three (with one team assigned to each garden plot), the undergraduate researchers were able to collect soil and vegetable samples and conduct analyses of their samples under the direction of PI and co-PIs. How have the results been disseminated to communities of interest?Lemke, Lawrence D. and Yifan Zhang. Metal and bacteria occurrence in Detroit urban agriculture. Michigan Department of Environmental Quality (MDEQ) biannual In-Service. May 25-26, 2016 Liyanage Nirasha Perera, Abdullah Ibn Mafiz, and Yifan Zhang. E. coli and Enterococcus contamination in soil and vegetables in Detroit Urban Gardens. International Association of Food Protection (IAFP) Annual Conference. Accepted, 2016 Ravansari, R., L.D. Lemke, and S.P. McElmurry, 2015, Spatial Variability and associations among trance metals in urban agricultural garden soils; Geological Society of America Abstracts with Programs, 47(7), p. 42. 2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015) What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Three metropolitan Detroit gardens with various levels of soil amendment practices were chosen for the study. In the summer of 2015, soil and vegetable samples were gathered from these gardens for bacteria and metal analysis. The soil amendment in the gardens ranged from yard waste compost, plant meal, to organic fertilizers and rich soil re-mineralizer. A total of 15 soil samples (five per garden) and 48 vegetable samples were collected for bacteria analysis. Both leafy greens and root vegetables were included. Target bacteria were E. coli and Enterococcus. E. coli was isolated by enriching samples in Lauryl Tryptose Broth, followed by spreading on McConkey Agar and biochemical testing. Enterococcus isolation was carried out by a selective enrichment in enterococcosel broth followed by growing bacteria on enterococcosel agar. Bacteria identity was confirmed by PCR. Both bacteria were prevalent in urban agricultural production and they may serve as an important source of food contamination. Forty percent of soil samples were positive for E. coli and 93% for Enterococcus. Twenty-three vegetable samples (48%) were contaminated by E. coli and 39 (81%) by Enterococcus. Garden variation was observed in the bacteria prevalence indicating possible impact of soil amendment on the microbial composition. A detailed characterization of bacterial isolates is ongoing and will provide insights into the potential transfer of bacteria from soil to vegetables grown in urban gardens. Urban gardening also poses risks associated with exposure to metals of anthropogenic origin primarily through inhalation of garden dust or ingestion of soils adhering to vegetable roots and leaves. For metal analysis, 65 soil samples were collected from each plot on a nested grid telescoping from a 10 m to 1 m spacing designed to capture small-scale spatial variability and facilitate geostatistical analysis. Soil samples were analyzed for the presence of trace metals, including As, Cu, Pb, and Zn. Samples were air dried, sieved, and analyzed using x-ray fluorescence (XRF) capable of measuring elemental metal concentrations with detection limits of 3 to 35 ppm. Measurements were calibrated using inductively coupled plasma-mass spectrometry (ICP-MS) analysis of standard reference soil materials prepared using U.S.EPA method 3051a and standard methods. The sensitivity of the XRF measurement method is currently being evaluated for metals at low concentrations near reported detection limits. Observed metal concentrations were generally higher in the two gardens located in Detroit. Most samples had Zn levels between 178 ppm and 212 ppm (Range: 100 ppm-296 ppm), Pb between 124 ppm to 158 ppm (Range: 66 ppm-204 ppm), and As between 9 ppm and 13 ppm (Range: 7 ppm-16 ppm). We also observed hotspots with very high levels of metals surrounded by "cold" areas, suggesting spatial variation in metal distributions in the gardens. Plans are now underway for sampling of an additional garden in Pontiac, Michigan during the summer 2016 growing season.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2016
Citation:
Liyanage Nirasha Perera, Abdullah Ibn Mafiz, and Yifan Zhang. E. coli and Enterococcus contamination in soil and vegetables in Detroit Urban Gardens. International Association of Food Protection (IAFP) Annual Conference. Accepted, 2016
Ravansari, R., L.D. Lemke, and S.P. McElmurry, 2015, Spatial Variability and associations among trance metals in urban agricultural garden soils; Geological Society of America Abstracts with Programs, 47(7), p. 42. 2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015)
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