Comparative Evaluation of Practical Functionality of Rapid Test Format Kits for Detection of Escherichia coli O157:H7 on Lettuce and Leafy Greens

被引:20
作者
D'Lima, C. B. [1 ]
Suslow, T. V. [1 ]
机构
[1] Univ Calif Davis, Dept Plant Sci, Davis, CA 95616 USA
关键词
GROUND-BEEF; IMMUNOMAGNETIC SEPARATION; LISTERIA-MONOCYTOGENES; O157-H7; PCR; SALMONELLA; PATHOGENS; PRODUCE; GROWTH; COMPONENTS;
D O I
10.4315/0362-028X-72.12.2461
中图分类号
Q81 [生物工程学(生物技术)]; Q93 [微生物学];
学科分类号
071005 ; 0836 ; 090102 ; 100705 ;
摘要
Multistate outbreaks of Escherichia coli O157:H7 infection in 2005 and 2006 associated with fresh and especially minimally processed produce greatly escalated the application of rapid pathogen detection systems to safety management in this food category. Pathogen testing was rapidly integrated into preharvest qualification for field lots, incoming raw produce, or final product. The raw produce and final product were incorporated into test-and-hold programs, typically within a 10-h time frame. To enhance consumer safety and provide guidance for the industry, an assessment of selected kits in comparison to a culture-based method was undertaken. Four primary kits were compared: the Neogen Reveal, SDI RapidChek, BioControl GDS O157, and Qualicon BAX O157 MP. Nine different leafy greens were freshly harvested and inoculated with a five-isolate mixture of E. coli O157:H7 at 10 CFU/25 g of sample, and cultures were enriched following the specified protocol. The PCR method was most consistent for identifying the presence of the inoculated pathogen in the shortest period of time. For the red-pigmented leafy vegetables red butter lettuce, curly endive, red lettuce, and lollo rosa, 13, 38, 88, and 100% false-negative results, respectively, were obtained with the immunoassays, but PCR detection was minimally affected. Immunoassays were negatively affected by delays in achieving critical threshold populations during the allowed enrichment period. Leafy green type, temperature abuse, and preharvest environment were unlikely to affect the results of PCR-based kits. Findings strongly suggest that product testing systems using 8-h detection cutoffs may give false-negative results. These issues become very important in high-throughput testing and retest protocols for presumptive pathogen-positive lots of produce.
引用
收藏
页码:2461 / 2470
页数:10
相关论文
共 42 条
[1]   Validation of Low-Volume Enrichment Protocols for Detection of Escherichia coli O157 in Raw Ground Beef Components, Using Commercial Kits [J].
Ahmed, Imtiaz ;
Hughes, Denise ;
Jenson, Ian ;
Karalisi, Tass .
JOURNAL OF FOOD PROTECTION, 2009, 72 (03) :669-673
[2]  
[Anonymous], 2006, Morb Mortal. Wkly. Rep, V55, P1045
[3]   Evaluation of culture- and PCR-based detection methods for Escherichia coli O157:H7 in inoculated ground beef [J].
Arthur, TM ;
Bosilevac, JM ;
Nou, XW ;
Koohmaraie, M .
JOURNAL OF FOOD PROTECTION, 2005, 68 (08) :1566-1574
[4]   Ecological factors influencing survival and growth of human pathogens on raw fruits and vegetables [J].
Beuchat, LR .
MICROBES AND INFECTION, 2002, 4 (04) :413-423
[5]   Simultaneous detection of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella strains by real-time PCR [J].
Bhagwat, AA .
INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY, 2003, 84 (02) :217-224
[6]   Effects of using reduced volumes of nonselective enrichment medium in methods for the detection of Escherichia coli O157:H7 from raw beef [J].
Bosilevac, Joseph M. ;
Koohmaraie, Mohammad .
JOURNAL OF FOOD PROTECTION, 2008, 71 (09) :1768-1773
[7]   Fitness of human enteric pathogens on plants and implications for food safety [J].
Brandl, Maria T. .
ANNUAL REVIEW OF PHYTOPATHOLOGY, 2006, 44 :367-392
[8]  
Calvin L., 2007, Amber Waves, V5, P24
[9]   Isolation and characterization of a wound inducible phenylalanine ammonia-lyase gene (LsPAL1) from Romaine lettuce leaves [J].
Campos, R ;
Nonogaki, H ;
Suslow, T ;
Saltveit, ME .
PHYSIOLOGIA PLANTARUM, 2004, 121 (03) :429-438
[10]   Effect of wounding on phenolic enzymes in six minimally processed lettuce cultivars upon storage [J].
Cantos, E ;
Espín, JC ;
Tomás-Barberán, FA .
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 2001, 49 (01) :322-330