Monitoring of biosafety of agricultural products from urban community gardens and roof gardens in Korea

Urban farming supplies emotional stability and fresh vegetables to participating persons, however, no information regarding the biosafety of agricultural products from urban farming is available. Here, we collected 260 samples of Chinese cabbages and lettuce from 4 urban community gardens and 6 roof gardens in Seoul from September through October 2012, and monitored the microbiological and parasitological contamination quantitatively and/or qualitatively. The mean counts of total aerobic bacteria and coliforms were 6.1 ± 0.8 log CFU·g⁻¹ (range, 5.4 ± 0.6~7.1 ± 0.8 log CFU·g⁻¹) and 4.0 ± 0.7 log CFU·g⁻¹ (range, 2.3 ± 0.6~6.1 ± 0.9 log CFU-g_-1), respectively. Coliforms were detected on 59.6% among 260 vegetable samples. There were no significant differences in the contamination levels of total aerobic bacteria and coliforms between the Chinese cabbages and lettuce, whereas both levels of vegetables from urban community gardens were higher than those of roof gardens (p > 0.05). Escherichia coli was isolated at 3.1% among whole vegetables, and contamination level was 1.5 ± 0.2 log CFU·g⁻¹. Among foodborne pathogens, Staphylococcus aureus was detected in 1.5%, however, Salmonella spp., Listeria monocytogenes and E. coli O157:H7 were not detected on any of the vegetable samples. We also found undefined parasite eggs from two samples of Chinese cabbages (0.8% of total vegetables we tested). From these study, we found the presence of microbial contamination of agricultural products from urban farming, thus we need further concern to improve the biosafety during production of agricultural products.