Survey of microbial contamination and characterization of Escherichia coli in kiwifruit orchards in Shaanxi, China, 2013.
The aim of the study was to survey three foodborne pathogens in kiwifruit orchards as a continuous monitoring program. A total of 193 samples were collected from 11 kiwifruit orchards in Shaanxi province in October 2013. Among the 193 samples, 68 Escherichia coli isolates were recovered, while no Staphylococcus aureus and Salmonella was recovered. All E. coli isolates were characterized by antimicrobial susceptibility testing, detection of virulence genes, and the ability to produce biofilm formation. The isolates were further examined by random amplified polymorphic DNA (RAPD) analysis. E. coli isolates displayed resistance most frequently to tetracycline (48.5%). Two E. coli isolates (2.9%) were positive for the eae gene (the intimin gene). All E. coli isolates lacked the ability to make biofilm formation. Multilocus sequence typing analysis demonstrated that one isolate in kiwifruit orchards shared the same sequence type with a human clinical isolate. RAPD results showed a close relationship among E. coli isolates from fresh fruit, fallen fruit, soil, air, and irrigation water. This study could provide a further understanding of microbial contamination in kiwifruit orchards based on our previous study and help growers take appropriate measures for prevention.
College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
Yuqing
Y
Feng
College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
Qinnan
Q
Yang
College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
Lingfang
L
Wang
College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
Guanghui
G
Li
College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
Xiaoying
X
Lv
College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
Qi'an
Q
Han
College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
Xiaobo
X
Liu
College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
Xiaodong
X
Xia
D029042:Actinidia / Q000382:microbiology*; D018829:Adhesins, Bacterial / Q000302:isolation & purification; D002681:China; D004926:Escherichia coli / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D029968:Escherichia coli Proteins / Q000302:isolation & purification; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D005638:Fruit / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D019105:Random Amplified Polymorphic DNA Technique; D013753:Tetracycline Resistance
D018829:Adhesins, Bacterial; D029968:Escherichia coli Proteins; C073819:eaeA protein, E coli