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Antibiotic residue surveillance at the Veterinary Services Laboratory

H. C. Hall, V. S. St. John, R. S. Watson, L. J. Padmore, and S. M. Parris,

Ministry of Agriculture & Rural Development, Veterinary Services Laboratory, The Pine, St. Michael, Barbados

Abstract Surveillance for antibiotic residues in foods of animal origin has been ongoing at the Veterinary Services Laboratory since 1996 with approximately 4,200 tests performed on meat, milk and eggs between January 1996 and April 15th 2003. Approximately 3% of these tests yielded positive results. When milk testing commenced, 6% of the samples tested positive, however, by the year 2002 this figure had fallen to 1%. The tests are performed with a Charm II 7600 analyser and samples of meat, milk and eggs are checked for the residues of four antibiotic classes: beta-lactams, aminoglycosides, sulphonamides and tetracyclines. Chloramphenicol was recently included for meat only. The majority of meat tested has been chicken and tetracyclines have been the most common residues detected. Only one of the 730 tests which were run on chicken in 2002 recorded a positive result.

___________________________________

Key words: antibiotic residues, beta-lactams, aminoglycosides, sulphonamides, tetracyclines, chloramphenicol, Charm II 7600 analyser

origin are one of the sources of concern among the public and medical health professionals (WHO/73, Bren). Many of the antibiotics used to treat bacterial infections in humans also have veterinary applications; they are used to treat infections in sick and injured animals and as prophylactics and growth promoters. In the latter two cases, the antibiotics are used at concentrations lower than those used for treatment; a potentially dangerous practice since it can encourage the production of antibiotic resistant strains of bacteria (Khachatourians, 1998 and Simonsen et al 1998). One example is the emergence of fluoroquinolone-resistant Campylobacter, one of several bacterial species that cause food poisoning in humans (Khachatourians, 1998 and Enberg et al.).

Background

The wide variety of medical and health programs on television as well as medical features in newspapers and magazines have made the general public more aware of food safety issues. Bacterial and chemical contamination of foods may happen at any stage of food production and may have lethal consequences for consumers caught unawares. The advent of globalisation has introduced major changes in business. An exporter will be more likely to trade if he can prove that his product is wholesome. On the other had, a trader can suffer great financial losses or may be put out of business if his products are found to be contaminated.

Antibiotic residues in foods of animal

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Antibiotic residues may produce allergic or anaphylactic reactions in susceptible individuals (with the sulphonamides and penicillins being of particular local importance). Some antibiotics are directly toxic, e.g. chloramphenicol which destroys blood-forming tissue. Allergic reactions and toxic side effects may have fatal consequences.

Most countries have established tolerance or safe levels (T/SL) or maximum residue levels (MRL) of drugs, below which it is considered that the drug may be safely used without harming the consumer. The Codex Alimentarius Commission is the accepted international agency responsible for food safety issues and has established T/SL and MRL listings for many antibiotics (MacNeil, 1998). A country may set its own levels or may accept those set by Codex Alimentarius.

Introduction

A residue testing system was purchased from Charm Sciences Incorporated (Malden, Massachusetts USA) by the Barbados Egg and Poultry Producers Association for the Veterinary Services Laboratory (VSL) in 1996.

The system purchased by the VSL is the same standard type used at six U. S. Food and Drug Administration (FDA) laboratories, 55 state laboratories and seven US Army facilities, as well as by industry and regulatory agencies for international trade (Charm Sciences). The detection capabilities can be adjusted to meet specific regulations of importing/exporting countries (e.g. Australia, New Zealand). Many of the Charm II tests for milk have been approved as adequate screening tests by the FDA and NCIMS (National Conference of Interstate Shipments) (Charm Sciences).

Antibiotics are placed into categories or families based on the compound from which they are derived. Charm II test kits are designed to detect all antibiotics of a specific family. For example, the beta-

lactam kit will detect all penicillins, whether man-made (synthetic, such as Amoxycillin) or from natural sources (e.g. Penicillin G). Ceftiofur as well as all other cephalosporins are also detected since their structure is very similar to that of penicillins. In some cases a kit exists for a specific drug, e.g. Cloxacillin. Although the tests may also be performed on liver, kidney, urine or serum (Charm Sciences Protocols), lean muscle tissue is the preferred specimen type.

General Test Principle

The tests utilize microbial or antibody receptor assay technology. The sample is incubated with a binding agent (microbial cells with specific receptor sites or with specific antibodies attached) and a tracer (the radio-labelled version of the antibiotic to be detected). The amount of tracer on the binding agent is measured using a scintillation counter and is compared to a pre-determined cut-off or control point. If contaminating antibiotic is present, it will prevent the binding of the tracer by occupying the receptors on the binding agent (Figure 1). The less labelled tracer detected, the more contaminating antibiotic there is present in the sample.

Charm II tests are very sensitive and have been compared favourably to high performance liquid chromatography (HPLC) (Anderson et al.) The tests are capable of detecting antibiotic residues at or below the MRLs and tolerance levels established by some countries (Table 1).

VSL currently conducts surveillance for residues of four (4) antibiotic classes: beta-lactams, aminoglycosides (gentamycin/neomycin type and streptomycins), sulphonamides and tetracyclines. Testing for chloramphenicol was recently included as part of an International Atomic Energy Agency (IAEA) project: ‘The Development of Strategies for the Effective Monitoring of Veterinary Drug Residues in Livestock and Livestock Products in Developing Countries’.

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Table 1. Antibiotic detection limits and drugs used

DETECTION LIMIT in parts per billion (ppb)

ANTIBIOTIC MEAT MILK EGGS

Beta-lactams 20 Penicillin G 4.5 Penicillin G -

Cloxacillin - 10 Cloxacillin -

Gentamycin/Neomycin 250 Gentamycin 24 Gentamycin -

Streptomycin 500 Streptomycin

25Gentamycin 500 Streptomycin

Sulphonamides 10 Sulfamethazine

10 Sulfamethazine

50 Sulphamethazine

Tetracyclines 100 Chlortetracycline

28 Chlortetracycline

200 Chlortetracycline

Chloramphenicol 0.15 Chloramphenicol

- -

Reproduced from Charm Sciences Literature

Tracer

Sample – containing antibiotic Antibiotic

Negative Positive

Binding Agent

Most sites filled by tracer CPM high

Many sites filled by unlabelled antibiotic PM low

Figure 1. Charm test principle

VSL currently conducts surveillance for residues of four antibiotic classes: beta-lactams, aminoglycosides (gentamycin/neomycin type and streptomycins), sulphonamides and tetracyclines. Testing for chloramphenicol was recently included as part of an

International Atomic Energy Agency (IAEA) project: ‘The Development of Strategies for the Effective Monitoring of Veterinary Drug Residues in Livestock and Livestock Products in Developing Countries’.

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Materials and Methods

Sample Collection

Meat, milk and egg samples were submitted by Animal Health Assistants (AHAs) of the Ministry of Agriculture and Rural Development, Environmental Health Officers (EHOs) of the Ministry of Health, private farmers, companies and veterinarians. Samples were collected at meat processing plants, farms, shipping containers inspected by AHAs and occasionally at post mortem by the Veterinary Pathologist. Lean muscle tissue of table quality was submitted fresh, cool (at 2 - 6°C) or frozen. At least 60g of chicken, pork, beef and lamb are required for a test profile. Milk was submitted cool (at 2 - 6°C) or frozen in plastic disposable 50ml centrifuge tubes or in 100ml Whirl-Pak bags. Fresh table eggs were submitted in egg crates at room temperature.

Reagents, Supplies and Equipment

Test kits comprise of tablet reagents for an antibiotic family, positive control standards, zero or negative control standards and buffer solutions in the case of meat and eggs. Also needed are scintillation fluid, distilled and deionised water and sodium hydroxide.

Sample Processing

Meat Sample Processing using Charm Sciences Protocols 3-8

Frozen meat was thawed completely. The tissue (fresh or thawed) was trimmed of excess fat and approximately 10g (20g for new chloramphenicol method) added to 30ml (20ml for chloramphenicol) MSU buffer in a plastic disposable centrifuge tube. The meat was homogenised in the buffer using a mini food processor and returned to the tube. This homogenate was placed in an 80°C dry bath for 30 or 45 minutes, depending on which test was being conducted. After incubation, the

tube of homogenate was cooled in an ice water bath for 10 minutes then centrifuged at high speed for 10 minutes. The resulting supernatant was decanted into another centrifuge tube for use in testing and the meat pellet was discarded.

Milk Sample Processing using Charm Sciences Protocols 9-14

Frozen milk was thawed completely and thoroughly mixed. Both fresh and thawed milk were centrifuged at high speed for 5 minutes to bring the butterfat to the surface. The samples were cooled in a freezer for 45 minutes before the fat layer was removed. The defatted milk was kept at 2 - 6°C until ready for testing.

Egg Sample Processing using Charm Sciences Protocols1-2

Eggs were broken into individual plastic disposable 150ml cups. Yolk and white of each egg were blended together using a spatula. 10ml of the mixture were poured into individually labelled plastic disposable centrifuge tubes, which were placed in a boiling water bath for 6 minutes. The heated egg was allowed to cool slightly then transferred to a mini food processor. 30ml of MSU buffer solution were added and the whole blended for 30 seconds. The suspension was returned to the centrifuge tube and then centrifuged at high speed for 10 minutes. The resulting supernatant was decanted into another centrifuge tube for use in testing and the egg solids were discarded.

Test Procedure

The basic test procedure is similar for all the drugs and for meat, milk and eggs. Procedures are either sequential or competitive. In sequential procedures, the sample is first incubated with the binding agent then re-incubated when the tracer has been added. In competitive procedures sample and tracer are added together and there is one incubation period. Other differences between tests are the volume of extract used, length of

5

4264

151

010002000300040005000

TESTS POSITIVES

Figure 2. Total tests and positives, November 1996 to April 2003

2335

1571

50 87 14 12195

0

500

1000

1500

2000

2500

Milk Chicken Turkey Pork Beef Mutton Eggs

Figure 3. Tests done by sample type. January 1996 – April 15th 2003

The number of tests performed for each antibiotic type and for each type of sample are shown in Table 2.

The details of the positive tests – number of positives for antibiotic type and sample type – are given in Table 3.

time extracts are incubated as well as incubation temperatures. Tests were performed following the protocols given in the Charm Operator Manuals received with each test kit. 1-14

Results

From the beginning of the antibiotic

residue surveillance program until April 2003, a total of 4,264 tests were performed, 151 of which yielded a positive result (Figure 2).

1722 of these were done on meat, 2335 on milk and 195 on eggs. Figure 3 also shows the type of meat being tested

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Table 2. The number of tests performed for each antibiotic type and for each type of sample.

TESTS

Antibiotic Milk Chicken Pork Beef Mutton Turkey Eggs TOTAL

Beta-lactams 405 313 15 4 2 10 749

Cloxacillin 377 377

Chloramphenicol 86 2 88

Enrofloxacin 50 4 54

Gentamycin / Neomycin 367 224 11 2 6 610

Gentamycin / Streptomycin 396 313 15 4 2 10 50 790

Macrolides 4 2 2 0 50 54

Novobiocin 4 0 4

Sulphonamides 405 267 21 3 3 10 41 750

Tetracyclines 377 316 21 3 3 10 54 784

TOTAL 2335 1571 87 14 12 50 195 4264

Table 3. Number of positives recorded according to antibiotic and sample type

Antibiotic Milk Chicken Pork Beef Turkey Eggs TOTAL

Beta-lactams 26 1 0 2 0 - 29

Cloxacillin 30 - - - - - 30

Gentamycin / Neomycin 30 7 3 0 0 - 40

Gentamycin / Streptomycin 2 0 0 0 0 0 2

Sulphonamides 4 1 2 0 2 0 9

Tetracyclines 17 12 4 1 1 6 41

TOTAL 109 21 9 3 3 6 151

Meat

Initially, the only residues being monitored were sulphonamides and tetracyclines. A wider range of tests was introduced in 1997. Macrolide testing was done briefly but was stopped after a list was compiled of the antibiotics most often used by veterinarians in Barbados (Table 4).

Tetracyclines were the most commonly detected residues in meat - 18 positives total, 12 in chicken, 4 in pork and 1 each in beef and turkey (Figure 4).

Chicken was the meat sample type most frequently tested. A total of 1,571 tests were performed on chicken over the period of discussion. The per capita

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consumption of chicken in Barbados is the second highest in the world after India (White, A Traveller’s Tale – Barbados), and most of the monitoring was

performed on this tissue (Figure 5). Othertypes of meat were also tested – pork, turkey, beef and mutton, in descending order of quantity

Table 4. Tests performed by antibiotic and tissue type

Chicken Pork Mutton Beef Turkey

Beta-lactams 313 15 2 4 10

Chloramphenicol 86 2

Enrofloxacin 50 4

Gentamycin / Neomycin 224 11 2 6

Gentamycin / Streptomycin 313 15 2 4 10

Macrolides 2 2

Sulphonamides 267 21 3 3 10

Tetracyclines 316 21 3 3 10

TOTAL 1571 87 12 14 50

1

7

1

12

21

32

4

9

21

32 1

3

0

5

10

15

20

25

Chicken Pork Beef Turkey

Beta-lactams

Gentamycin /Neomycin

Sulphonamides

Tetracyclines

TOTAL

Figure 4. Residues detected in meat according to sample type

The number of chicken meat samples received for residue testing increased in 1999 with the start of the VSL’s food safety project: “A Monitoring Programme for Veterinary Drug Residues and

Pathogenic Bacteria in Foods of Animal Origin”. The number of positives detected in chicken has declined from approximately 3% at the beginning of the monitoring project to less than 1% in 2003

8

9 4 12 1

283

9

202

3

331

7

730

1

1571

210

200

400

600

800

1000

1200

1400

1600

1996 -1997

1997-1998

1998-1999

1999-2000

2000-2001

2001-2002

2002-2003

TOTAL

Figure 5. Number of tests and positives for chicken, November 1996 to April15th 2003

Milk

A total of 2,335 tests were conducted on bulk tank and individual cow samples between 1997 and 2003 (Figure 6).

At the start of the residue surveillance program, approximately 6% of samples tested positive for various residues. By

the end of 2002, the figure had declined to approximately 1%.

Figure 7 shows tests performed for the various antibiotic classes. Four tests each were performed for Novbiocin and Macrolides. Tests for these two antibiotics ceased after the compilation of a list of drugs most often used to treat dairy cattle

Figure 6. Antibiotic residue tests in milk, 1997 – April 2003

Positive

23515

616

38

524

30

444

17

492

5 24 4

2335

109

0

500

1000

1500

2000

2500

1997-1998 1998-1999 1999-2000 2000-2001 2001-2002 2002-2003 TOTAL

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405 377367 396

4 4

405 377

2335

0

500

1000

1500

2000

2500

1

Beta-lactams

Cloxacillin

Gentamycin/Neomycin

Gentamycin/Streptomycin

Macrolides

Novobiocin

Sulphonamides

Tetracyclines

Figure 7. Antibiotic tests by drug class, 1997 – 2003

Most of the positive results recorded were for beta-lactams (combined total beta-lactams and cloxacillin, 70), followed by tetracyclines (40) and gentamycin/neomycin-type aminoglycosides (40) (Figure 8).

Eggs

A total of 195 tests were performed on eggs. Of these, six yielded a positive result (Figure 9).

However, these results are biased since most of the tests were not done on random samples, but rather on eggs from layers after treatment during the moult. Samples are submitted to certify that all antibiotics (namely tetracyclines) have left the birds’ systems and are no longer contaminating the eggs

When the screening of eggs began, it was decided that four categories of antibiotics would be monitored. These were macrolides, streptomycin, sulphonamides and tetracyclines (Figure 10).

19%

20%

26%

6%

28%

1%

Beta-lactams

Cloxacillin

Gentamycin/Neomycin

Gentamycin/Streptomycin

Sulphonamides

Tetracyclines

Figure 8. Antibiotic residues detected in milk 1997 – 2003 by percentage

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Tetracyclines27%

Gentamycin / Streptomycin

26%

Macrolides26%

Sulphonamides21%

Figure 9. Residue tests in eggs, 1999 - 2003

54

27

104

6 10

195

6

0

50

100

150

200

1999-2000 2000-2001 2001-2002 2002-2003 TOTAL

Figure 10. Antibiotic classes tested in eggs, 1999 – 2003

Positive Test

about these animal derived foods. Very few samples from imported meats have been tested and therefore their residue status remains unknown.

Smaller poultry producers whose samples were submitted by the EHOs from the Ministry of Health were investigated and counselled when positives were reported from their farms (personal communication). It

Discussion

The incidence of contamination in both chicken and milk has declined since the monitoring system came into effect. More comprehensive testing of other meat types and eggs will be needed before any conclusions can be drawn

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should be noted that most of these samples were collected from small poultry farmers in the St. Thomas area.

Antibiotics are only routinely added to animal starter feeds manufactured in Barbados because young animals are susceptible to diseases which can result in serious intestinal problems such as scouring (diarrhoea) (Pinnacle Feeds, 2002).

The Pine Hill Dairy (PHD) routinely screens bulk tank milk for beta-lactams and tetracycline residues using different screening tests from those employed at VSL (Idexx SNAPTests, Idexx Laboratories Inc., Maine USA). Two or three dairy farms are screened at random on a daily basis. If the milk tests positive, it is rejected on the spot. Bulk tank milk is tested daily as it is brought into the PHD. If a tank tests positive, two more tests are conducted. Should the milk still register as positive, milk from the individual farms is tested to identify the violator. Once the positive farm is known, milk from this source is rejected and screening is conducted daily until residue test results are negative for three consecutive days (Alkins, personal communication). If there is some question as to the veracity of a result, a farmer will on occasion submit a sample for independent testing at the VSL.

The status of antibiotic residues in eggs is unclear except from those farms tested by the VSL. Antibiotics are administered prophylactically when the layers are forced to moult to prevent ovarian infections to which the birds are more susceptible to at this time. The submission of samples from other sources would give a clearer picture of the use of antibiotics on other farms.

Antibiotic residues can be prevented from entering the food chain at the producer level if farmers and processors are educated about the potential hazards associated with antibiotic residues in foods

of animal origin. Producers and processors should also be made aware of the financial losses they may incur as a direct result of having product dumped, or not being able to trade as a result of contamination, which has happened to farmers in Europe and the USA (FDA 2002).

There are now several programs in the USA and Europe which make use of HACCP principles in quality management systems for farms, e.g. Milk & Dairy Beef Quality Assurance Program Milk and Dairy Beef Residue Prevention Protocol. In this program, the farmer works closely with a veterinarian and follows a 10-step process to minimise the risk of antibiotic residues entering the food chain. The Pine Hill Dairy recently held a series of seminars the theme of which was the above quality assurance program.

At present, Barbados has no legislation governing the sale or use of veterinary drugs (Gary, 2001), and there are no set safe/tolerance levels or maximum residue limits for veterinary drugs in foods of animal origin; such legislation needs to be enacted. Medication for use in animals may be purchased over the counter. Restriction of drug sales to a licensed veterinarian could greatly reduce the indiscriminate and sometimes incorrect use of antibiotics.

Conclusion

Antibiotic residue testing should be increased for eggs and meat samples other than chicken. Imported meat and meat products also need to be tested.

Acknowledgements

The authors would like to thank the following for their assistance and communications:

Mr. Bryan Alkins, Farm Liason Manager,

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Pine Hill Dairy, Mr. Geoffrey Goddard, Chickmont Foods, Mr. Steven Holmes, Technical Assistance Director, Charm Sciences, Mr. Brad Johnson, Technical Assistant, Charm Sciences, Ms. Jennifer Melanson, Technical Assistant, Charm Sciences, Ms. Andrea Osbourne, Environmental Health Officer, Ministry of Health, Mr. Bryan Sanford, Senior Animal Health Assistant, Ministry of Agriculture, Mr. Adrian Yarde – Extension Officer, Roberts Manufacturing Company, Farmers, veterinarians and others who made contributions in any way.

References

Charm II Test. Operator’s Manuals

1. Charm II Test for Antimicrobial Drugs in Eggs. EGGS14.DOC (JULY 2002)

2. Charm II Test for Macrolides in Eggs

3. Charm II Test for Beta-lactams in Tissue, Serum and Urine. Operator’s Manual PMSU03.DOC (MAR 2002)

4. Charm II Test for Chloramphenicol in Tissue, Serum and Urine. Operator’s Manual ATBL002.DOC (AUG 2002)

5. Charm II Test for Gentamicin and Neomycin-type Aminoglycosides in Tissue, Serum and Urine. Operator’s Manual gent amino in tissue06.DOC (OCT 2002)

6. Charm II Test for Streptomycins in Tissue, Serum and Urine. Operator’s Manual STMSU07.DOC (JULY 2002)

7. Charm II Test for Sulfonamides in Tissue, Serum and Urine. Operator’s Manual SULF012.DOC (AUG 2002)

8. Charm II Test for Tetracyclines in Tissue, Serum and Urine. Operator’s Manual TETRA10.DOC (JAN 2003)

9. Charm II Beta-lactam Test for Amoxycillin, Ampicillin, Ceftiofur, Cephairin and Penicillin G (Competitive Assay). Operator’s Manual Validated for Raw, Commingled Bovine Milk. Potocol ID – BLCOM01 (JULY 2001)

10. Charm II Test for Cloxacillin (Competitive Assay). Operator’s Manual Validated for Raw, Commingled Bovine Milk. Protocol ID – CLXCOM6 (DEC 2000)

11. Charm II Aminoglycoside Test for Gentamicin and Neomycin at U.S. Tolerance/Safe Levels (T/SL) or Maximum Residue Limits (MRL) (Competitive Assay) Operator’s Manual for Milk. Protocol ID – Gent comp 06.doc (May 2001)

12. Charm II Aminoglycoside Test for Gentamicin, Streptomycin and Dihydrostreptomycin (Competitive Assay). Operator’s Manual for Raw, Commingled Bovine Milk. Protocol ID – STCOM06 (10/31/00)

13. Charm II Sulfa Drug Test for Sulfadiazine, Sulfadimethoxine, Sulfamethazine and Sulfathiazole (Competitive Assay) Operator’s Manual Validated for Raw, Commingled Bovine Milk . Protocol ID – fdasulf2 (DEC 2000)

14. Charm II Tetracycline Test for Chlortetracycline, Oxytetracycline and Tetracycline (Competitive Assay). Operator’s Manual for Raw, Commingled Bovine Milk. Protocol ID – TETCOMDIL02 (JULY 2001)

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Texts

Pelczar Jr., M.J., Chan, E.C.S. and Krieg N. R. 1986. Microbiology 5th ed. McGraw-Hill

USDA, 1999. United States Department of Agriculture, Food Safety and Inspection Service. National Residue Data

Papers

FAO/IAEA 1997 . Final Report of the FAO/IAEA Consultants Meeting on “Monitoring of Veterinary Drug Residues in Developing Countries” December 1-4 1997

GARY, S., 2001. Draft proposal for implementing a national residue control program for animal derived human food products in Barbados.

KHACHATOURIANS G. G. 1998. Agricultural use of antibiotics and the evolution and transfer of antibiotic-resistant bacteria. CMAJ Nov 3 1998;159(9)1129 – 1136

MACNEIL J. D. (1998) International Approaches to the Regulation of Veterinary Drug and Related residues in Foods for Human Consumption. Journal of Food Hygenic Society of Japan July; 39(3):284 – 298

MACNEIL J. D. (1998) Residue Testing and Control Strategies. Journal of Food Safety 18:341 – 354

SIMONSEN G. S., HAAHEIM H, DAHL K. H., KRUSE H., LOVSETH A., OLSVIK O., AND

SUNDSFJORD A. 1998. Transmission of Van A-type vancomycin resistant enterococci and Van A resistance elements between chicken and humans at avoparcin-exposed farms. Microb Drug Resist Winter; 4 (4):313 -318

WALLNER-PENDELTON E, SCHNEIDER N. R., AND

SUMER S. 1993. Preventing Bacterial Contamination, Medication and Other Chemical Residues in Poultry Meat and

Eggs.

WEGNER H. C., AARESTRUP F. M., JENSEN L.B., HAMMERUM A. M., AND BAGER F. 1999. Use of antimicrobial growth promoters in food animals and Enterococcus faecium resistance to therapeutic antimicrobial drugs in Europe. Emerg Infect Dis May-Jun; 5(3):329-335

Articles

Pinnacle Feeds, 2002. “Feed Additives, Why we use them and How they Benefit You” The Feed Solution, Issue3; Pinnacle Feeds Ltd.

BEST, R., 2002. “Food can be a Killer”. Best on Tuesday, Daily Nation, February 12th 2002 p 8

Internet documents

About Charm – A Brief Profile http://www.charm.com/about.htm

‘Antibiotic Use in Food-producing Animals must be Curtailed to Prevent Increased Resistance in Humans’ (1997) October Press Release WHO/73 http://www.who.int/archives/inf-pr-1997/en/pr97-73.html

BILLY TJ. “Food Safety Issues Affecting International Trade” (2000/09/7 Speech before the National Conference on Animal Production Food Safety, St. Louis, MO) FSIS/USDA

http://www.fsis.usda.gov/oa/speeches/2000/tb_apfs.htm

BREN L. The Battle of the Bugs: Fighting Antibiotic Resistance. USDA Consumer Magazine 2002 Jul – Aug http://www.fda.gov.fdac/features/2002/402_bugs.html

Charm II 7600/6600 System http://www.charm.com/6600.htm

ENGBERG J, AARESTRUP FM, TAYLOR DE,

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GERNER-SMIDT, AND NACHAMKIN I. Quinolone and Macrolode Resistance in Campylobacter jejuni and C. coli: Resistance Mechanisms and Trends in Human Isolates. Emerg Infect Dis 2001 Jan - Feb; 7(1) http://www.cdc.gov/ncidod/eid/vol7no1/engberg.htm

‘Sozinho Dairies Pay $140,000 to Settle Contempt Complaint’ (2002) Feb FDA Talk Paper

http://www.fda.gov.bbs/topics/ANSWERS/2002/ANS01137.html

“The Medical Impact of the Use of Antimicrobials in Food Animals – Report of a WHO Meeting. Berlin, Germany 13 – 17 October 1997

http://www.who.ch/emc/diseases/zoo/zoo97_4.html

United States Regulatory Approved Charm Tests http://www.charm.com/approv2.htm

WHITE N. “Travellers tale – Barbados”

ttp://www3.open.ac.uk/events/200265_54438_o1.pdf

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Appendix A Table 1. Charm Food Safety Tests: Charm II Testing Range*

Analyte Muscle Urine Serum Egg Feed

Product Contact Surface

Honey Milk Farmed

Fish Fruits &

Vegetables

Clear Juice, Water, Beer &

Wine

Ground Nuts

Cooked Meat& Seafood

Sulphonamides X X X X X X X X Beta-lactams X X X X X X X X X Tetracyclines X X X X X X X X Macrolides X X X X X X X X Amphenicols X X X X X X X X Aminoglycosides:

X X X X X X X X Streptomycin type

Gentamycin type X X

Spectinomycin X Novobiocin X Aflatoxins X X X X Pasteurisation Efficiency1 X

Pesticides X X X X X X ATP/Hygiene X Microbial Quality X Charm Heat Efficiency Test 2 X X

1Measures alkaline phosphatase activity of raw milk in pasteurised milk (PasLite)

2Measures phosphatase activity of raw meat on surfaces and in cooked samples (CHEF Test)

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