Memorandum
| Date | May 10, 2000 |
| From | Consumer Safety Officer, Thru Chief, Domestic Branch (HFS-636) |
| Subject | Domestic Produce Sampling Assignment - FY 00/01 DOEP # 00 - 16 FOI VERSION |
| To | [Addressees Redacted] |
OBJECTIVE
BACKGROUND
American consumers enjoy one of the safest supplies of food in the world. However, over the last several years the proportion of foodborne illnesses associated with domestic and imported fresh fruits and vegetables has increased. In January of 1997, President Clinton announced a Food Safety Initiative to improve the safety of the nation's food supply. The Department of Health and Human Services, the Department of Agriculture, and the Environmental Protection Agency sent a report to the President, in May of 1997 that identified fresh produce as an area of concern. In October 1997, President Clinton announced an Initiative to Ensure the Safety of Imported and Domestic Fruits and Vegetables” (Produce Safety Initiative) to provide further assurance that fruits and vegetables consumed by the American public meet the highest health and safety standards.
Most fresh fruits and vegetables are grown in fields and orchards that are non-sterile environments. Growers have less control over conditions in the field compared to an enclosed processing facility. The surfaces of produce contain microorganisms. Usually, of microbiologically lethal processing. Due to complex supply and distribution patterns, outbreaks that occur may be widespread. Complex distribution patterns and a relatively short shelf life make trace back of fresh produce particularly difficult. In FY 97 and 98, the FDA has conducted several surveys of domestically produced fresh fruits and vegetables including:
The Center for Food Safety and Applied Nutrition (CFSAN) needs more data on the incidence and extent of pathogen contamination for selected fresh domestic and imported produce to assist in the development of additional policy for the Produce Safety Initiative. Our purpose is not to attempt to detect every incidence of low level sporadic contamination. Our purpose is to detect those levels of contamination that might result from a failure to follow adequate GAPs and GMPs. In March of 1999, CFSAN initiated the "Imported Produce Sampling Assignment". This assignment will be the domestic complement to that assignment.
INVESTIGATIONAL APPROACH
This assignment is to be implemented upon receipt. All collections are to be completed by April 30, 2001. All sample analyses are to be completed by May 15, 2001.
Do not schedule sample collection of fresh produce without first coordinating the collection/shipment with the analyzing laboratory.
Only produce grown in the United States is to be collected.
Additionally, produce is only to be collected when the grower can be positively identified at the time of collection - this information MUST be on the collection report.
It is imperative that the District coordinate sample collection and shipment with their servicing laboratories in order to ensure that the sample will be analyzed expeditiously.
[Chart of Collecting Districts and Analyzing Districts Redacted]
See Attachment A for the complete collection schedule. Please note that when a state's initials appear before a commodity on attachment, that item is to
be collected from a grower in that state.
Where indicated, simultaneously collect the samples listed on Attachment D: Additional Sampling Schedule. These samples are to be sent to CFSAN for further analysis. These samples should be collected from the same lot as a sample collected to fulfill the District Sampling Obligation. In instances where samples are requested for both field lab analysis and CFSAN analysis, collect a split sample.
Collect surveillance samples. Samples must be officially sealed to ensure integrity. It is not necessary to document interstate commerce at the time of collection. In the event that a sample is violative, it will then be necessary to go back and determine if the sample was from an inter- or intra- state lot.
CFSAN recommends that all collections be made at packers; however, if a district can collect samples at re-packers or wholesalers and be able to positively identify the grower, they may do so. A collected sample will not meet the criteria of this assignment unless under associated firms, the grower is listed in addition to the listing for where the sample is collected.
If readily available, obtain either an actual label or a photograph of a label along with the codes on each container sampled.
If a dealer informs the FDA investigator that a sampled lot will be held pending receipt of FDA analytical results or specifically requests that FDA inform him or her of the results, the investigator will coordinate notification to the dealer of the results once the analysis by the servicing lab is complete. The initial notification may be done by district or lab personnel and made by telephone.
The intent of this assignment is to collect 125 samples of each of eight products from as large a number of growers as possible. Districts should not collect repeat samples of the same product/grower combination under this assignment without prior CFSAN concurrence.
Collect all samples ASEPTICALLY - see IOM, Chapter 4, Section 426.
| Note: | Instead of using the sterile disposable gloves specified in the IOM, it is acceptable to simply turn a garbage bag inside out over the hand so that the inside of the bag becomes the sterile outside of the temporary glove in order to pick up subsamples. As with the disposable gloves, a fresh temporary glove should be used for each subsample. |
| Note: | It is important that each subsample be in a separate bag and that closed sampling controls, i.e., samples of unused collection bags, disposable gloves and temporary gloves, be sent with the shipment to the laboratory. All controls must be identified and placed in the container with the officially sealed sample. |
Ship samples refrigerated by the fastest means possible to the Laboratory specified in Attachment A.
Sampling containers for large whole produce and head/bunches samples, only:
NOTE: These are only to be used for the collection of "whole" raw produce samples such as cantaloupes or heads of celery where normal size sterile bags (whirl-packs) cannot accommodate the size of the raw produce.
Ensure that the coolant used does not come in direct contact with the commodity.
Take sub samples at random to ensure that the sample is representative of the lot.
NOTE:
For cantaloupe and celery: a sub sample will consist of one cantaloupe or bunch of celery. However, two units will need to be collected if necessary to reach the minimum subsample weight of 454-grams (1 pound).
For strawberries and tomatoes: if bulk shipments are encountered, a sub sample will consist of 454 grams (1 pound) of product. If product is shipped in retail size containers, then collect enough retail containers to equal 454 grams per subsample.
See Attachment D for the additional sampling collection schedule. The samples for shipment to CFSAN should be collected from the same lot as the sample collected to fulfill the District sampling obligation for that month's assignment.
It is imperative that the districts coordinate the additional sample collection and shipment with CFSAN in order to ensure that the samples will be analyzed expeditiously. Attempt to ensure a weekly sample shipment flow to CFSAN. Contact Tony Tran (Office of Special Research Skills, Microbiology Methods Development Branch, HFS-516) as necessary at (202) 205-5253.
Additional sampling will be used by CFSAN for a research project. CFSAN results will not be forwarded back to the collecting districts. Therefore, it is not necessary to use official seals on these samples.
Sampling containers for whole produce head/bunches samples only: see A/#3 above.
FDA/CFSAN/Sample Custodian, HFS-516
Attention: James Bland
200 C street, SW
Washington, D.C. 20204
(202) 205-5284
| Note: | The perishable nature of these products is critical. Therefore, the analyses should start as soon as the samples arrive in the laboratories. Samples should not be frozen at any time prior to analysis. |
Refer to Attachment B for the number of samples projected for each analyzing laboratory.
All commodities will be analyzed for the following:
E. coli, EHEC (E. coli O157:H7), Salmonella. Enumeration of Salmonella will be conducted when this pathogen is detected.
Cantaloupe, celery, parsley, scallions, and tomatoes will also be analyzed for Shigella.
| Note: | Laboratories are to perform the E. coli O157:H7, Salmonella, and Shigella analysis first if at all possible. |
Presumptive positive findings at 72 hours may be used to initiate regulatory action. Call assignment regulatory contact, William Correll at 202-205-5410 and also the compliance contact in the collecting district.
In order to conduct meaningful bacterial analyses, the samples must be prepared for analysis in a manner that closely simulates the actions typically taken by consumers who provide minimal preparation (e.g., washing and/or trimming) prior to consumption.
Cantaloupe, strawberries, tomatoes: none required.
Scallions, cilantro, parsley: if root is still attached, aseptically remove the root prior to "sub sample rinse".
Loose-leaf lettuce: aseptically remove damaged outer leaves and those with visible dirt prior to preparation of "sub sample rinse".
Celery: aseptically remove 3-4 outer "stalk leaves" (ribs). (Perform a light rinse to remove visible dirt. "Light rinse" means to place produce commodity under running tap water.). Next use these "stalk leaves" (ribs) to prepare the "sub sample rinse".
Weigh each individual subsample and add an equal amount of Butterfield's phosphate buffer solution to obtain a 1:1 dilution. Gently shake the bag with contents for 5 minutes using a shaker (e.g., orbital) at 100 rpm. This is considered to be the "sub sample rinse".
From each sub sample rinse (10 analyses/sample):
Prepare decimal dilutions by removing 50 ml (of sub sample rinse) into 450 ml of Butterfield's phosphate buffer solution (1:10). Then follow methodology as outlined in the BAM, 8th Ed., Revision A, 1998, for E. coli.
E. coli analysis: inoculation of the LST tubes for a 3-tube MPN will be conducted from 10-1 to 10-5 dilutions, only. It will not be necessary to prepare/use tubes for dilutions greater than 10-5 for an end-point. Therefore, the maximum result that can be encountered would be >110,000 organisms/g.
EHEC (E. coli O157:H7): From each sub sample rinse (10 analysis/sample) remove 125 ml (of sub sample rinse) and place in a sterile beaker/flask with 125 ml 2X EEB to perform the E. coli O157:H7 analysis. Then follow methodology as outlined in BAM, 8th Ed., 1998, Revision A, Chapter 4, page 4.22, step 2. “Enrichment, b. incubate”. This method is to be used for detection and confirmation.
6-HOUR ENRICHMENT STEP FOR EHEC SHOULD BE OMITTED FOR THIS ASSIGNMENT ONLY.
Note: Since the normal flora levels are not anticipated to be high in these products, the level of antibiotic cefixime to be used in the EEB enrichment is recommended to be reduced to one-fourth of that stated in the BAM, to avoid the inhibition of any E. coli O157: H7 that may be present. Modification to the preparation of EEB (EHEC enrichment broth): See BAM, Ch. 4, page 4.22. Media Preparation in lieu of using 0.05 mg/L cefixime; use 0.0125 mg/L.
DO NOT USE THE DYNA BEADS METHOD.
Positive E. coli O157:H7: Conduct Pulsed-Field Gel Electrophoresis (PFGE) analysis on all positive E. coli O157:H7. Outbreak-associated strains must be analyzed by PFGE within 4 days of isolation while isolates from these routine surveillance samples should be PFGEd within two weeks of isolation. The TIFF images of the PFGE gels then must be submitted to Dr. Farukh Khambaty (HFS-517) at CFSAN for QC/QA confirmation and submission to the PulseNet database.
PFGE analysis will be as follows: [Lab listing chart redacted]
Since CFSAN has a significant research and methods development program underway on this pathogen, we request that the field labs save two representative E. coli isolates from each positive sample and periodically mail the collected strains to Dr. Peter Feng (HFS-515) at CFSAN.
The correct shipping address for Drs. Feng and Khambaty is:
FDA/CFSAN/OSRS/DMS/MEB
ATTN:
200 C Street, SW
Washington, DC 20204
Note: It is recommended that only those microbiologists previously trained in PCR be utilized to perform the Shigella analysis.
PCR primers and the positive control were supplied to each District as part of the Import assignment. If the District has not received their primers and the positive control or needs additional materials, please notify Keith Lampel, the CFSAN scientific contact for Shigella,.
Shigella will be done on a composite basis (i.e., 2 composites per sample). Each composite for Shigella analysis will consist of 250 ml.
Prepare each composite by removing 50 ml from each of five (5) sub sample rinses into a sterile beaker/flask and mix thoroughly.
Remove 100 ml (of each composite) and place into centrifuge tubes and spin at 2000 rpm for 3 min to pellet plant material. Then follow methodology as outlined in Attachment C entitled, "Detection of Shigella by the Polymerase Chain Reaction".
This method is to be used for detection. For confirmation, send the remaining PCR product to Keith Lampel, the CFSAN Scientific contact for Shigella for DNA sequencing.
Salmonella will be done on a composite basis (i.e., 2 composites per sample). Each composite for Salmonella analysis will consist of 375 ml.
Prepare each composite by removing 75 ml from each of five (5) sub sample rinses into a sterile flask. Add 3375 ml of lactose broth. Mix well by swirling and determine pH with test paper. Adjust pH, if necessary, to 6.8 ± 0.2. Mix well and loosen cap (if using foil cap; otherwise, use cotton plug.)
Incubate 24±2 h at 35° C. Then follow the methodology as outlined in BAM, 8th Ed., Revision A, 1998, for Salmonella, Chapter 5.
Screen all samples for Salmonella using rapid methods listed in the memo entitled, "Guidance for the Use of Rapid Methods for Food Microbiology" dated April 24, 1998 If the laboratory does not have a copy of the memo, they should request a copy from the Division of Field Science, HFC-140. If there is a presumptive positive based on the test kit, then perform [1] confirmation analyses as outline in the BAM and [2] Most Probable Number Test (MPN) as per Attachment E: Determination of Most Probable Number of Salmonella in Rinse Water from Selected Produce. The original rinse composite should be used for all tests. While waiting for the test results needed to determine if subsequent tests are required, refrigerate the rinse. The MPN procedure needs to be done within 3 days of obtaining the presumptive positive results.
Salmonella Isolates: Copies of Salmonella isolates should be shipped simultaneously to DEN microbiology laboratory for antibiotic sensitivity assay and to ARL for speciation. PFGE analysis will be done at the same laboratories indicated under E. coli O157:H7. TIFF images are to be sent to CFSAN (Farukh M. Khambaty, Ph.D.) for QC/QA confirmation and submission to the CDC-PulseNet database.
Submit cultures on BHI agar slants in screw-cap tubes (13x100mm or 13x125mm) with caps secure tightly. Label each tube with sample number and sub sample number. Submit copies of the collection report and analytical worksheets. Place cultures in culture container with official FDA seal. Place accompanying records inside shipping carton but not within officially sealed culture container. Prepare cultures for shipment according to requirements for shipment of etiological agents. Label secondary shipping container with the address below. Send container by most rapid mail service available. Maintain duplicate cultures of those submitted for all cases, which are under consideration for legal action.
Submit Salmonella isolates for serotyping to:
Submit Salmonella isolates for antibiotic sensitivity assay to:
HARD COPY REPORTING/ RESOURCES
CFSAN has entered the majority of this assignment into FACTS; however, because of limitations in the FACTS system, it is important that the Attachments A & D Collection Schedules are followed. FACTS will not accommodate the twelve monthly collection dates listed in those schedules nor will it allow the CFSAN samples to be entered since there is no laboratory designation for CFSAN. When a split sample is collected for a field lab and for CFSAN, it is important that collection of the CFSAN sample be noted in the remarks section of the collection report of the field lab sample. The FACTS Assignment number is 113427, the PAC is 03F100, and the PAF is MIC.
Partial resources for this assignment were planned in the FY 00 ORA Workplan under Import and Domestic Micro Assignments. Additional resources will be planned for in the FY 01 ORA Workplan. For FY 00, utilize the resources for this assignment as follows:
Regardless of where the resources come from, Sample Collection and Analysis should be reported only under PAC 03F100.
No import operations are to be performed or reported against this assignment even when resources from the Import Produce Assignment are used.
The following Product Codes should be used:
| Loose-leaf Lettuce | 24T( )B32 | 24T( )C32 |
| Mesculin (& other loose-leaf varieties) | 24T( )B47 | 24T( )C47 |
| Escarole, Endive | 24T( )B30 | 24T( )C30 |
| Witloof, Chicory Leaf | 24T( )B34 | 24T( )C34 |
| Lamb's Lettuce, Mache | 24T( )B35 | 24T( )C35 |
| Romaine | 24T( )B32 | 24T( )C32 |
| Salad mixes | 24T( )B99 | 24T( )C99 |
| Strawberries | 20A( )B14 | 20A( )C14 |
| Cantaloupe | 22A( )B01 | 22A( )C01 |
| Parsley | 24T( )B21 | 24T( )C21 |
| Celery | 24T( )B11 | 24T( )C11 |
| Scallions/Green Onions | 25J( )B04 | 25J( )C04 |
| Cilantro | 24T( )B46 | 24T( )C46 |
| Tomatoes | 24F( )B50 | 24F( )C50 |
PRIORITY
This assignment has high priority. This assignment is to be implemented upon receipt. All collections are to be completed by April 30, 2001. All analyses are to be completed by May 15, 2001.
REGULATORY/ADMINISTRATIVE FOLLOW-UP
Regulatory follow up will be the same for this assignment as for any microbiological program/assignment. If any of the following microorganisms are detected and confirmed:
The collecting district and the CFSAN Case Processing Contact, William Correll, should be notified immediately. If the firm has held product pending the results of the tests, the district should encourage the firm to either recondition the product to destroy the pathogen or to destroy the product if reconditioning is not possible. If the firm has distributed the product, the collecting district should encourage the firm to conduct a voluntary recall. If the lot is still available, the district should pursue seizure as appropriate provided that interstate commerce can be documented. If no interstate commerce can be documented, notify state officials.
SUMMARY/EVALUATION:
The Office of Plant and Dairy Foods and Beverages will prepare a summary and evaluation of the findings within 120 days of the completion of the assignment.
CONTACTS
CFSAN Assignment Contact: Andrea Lee Wade, Office of Field Programs, Division of Enforcement and Programs, Domestic Programs Branch, HFS-636 at (202) 205-8164
CFSAN Case Processing Contact: William Correll, Office of Field Programs, Division of Enforcement and Programs, Case Processing Branch, HFS-607 at (202) 205-5410
CFSAN Scientific Contacts:
E. coli and EHEC O157:H7: Peter Feng, CFSAN, Office of Special Research Skills, Division of Microbiological Studies, Microbiological Methods Development Branch, HFS-516 at (202) 205-4518.
Salmonella: Wallace H. Andrews, CFSAN, Office of Special Research Skills, Division of Microbiological Studies, Microbiological Methods Development Branch, HFS-516 at (202) 205-4462.
Shigella: Keith Lampel, CFSAN, Office of Plant, Diary Foods, and Beverages, Division of Virulence Assessment, Virulence Mechanisms Branch, HFS-327 at (202) 205-4515.
ORA Analytical Inquiries: Atin Datta, Division of Field Sciences, HFC-141 at (301) 827-7605.
ORA Investigational Contact: Jody Robinson, Division of Emergency and Investigational Operations, HFC-130 at (301) 827-6691.
| Andrea L. Wade |
Attachment A Sampling Schedule
Attachment B Samples Projected for Each Analyzing Laboratory
Attachment C Detection of Shigella by the Polymerase Chain Reaction
Attachment D Additional Sample Collections for CFSAN Analysis
Attachment E Determination of Most Probable Number of Salmonella in Rinse Water from Selected Produce
cc: [cc List Redacted]
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