Quantification of Antibiotic Residues and Determination of Antimicrobial Resistance Profiles of Microorganisms Isolated from Bovine Milk in Lebanon


The rapid growth of dairy sectors in the Middle East, particularly in Lebanon, led to extensive use of antibiotics to enhance the health and productivity of animals. Prolonged usage may lead to antibiotic residues in foods of animal origin; hence, the emergence of antimicrobial resistant microorganisms. Accurate data on the antibiotic usage in livestock treatment, antibiotic residues and antimicrobial resistances in raw milk in Lebanon are lacking. This study aimed to investigate the types and usages of antibiotics in cattle, their residual levels and the potential microbial resistances in raw milk samples. A questionnaire-based survey identified Gentamicin and Streptomycin as the most frequently used antibiotics. Selected raw milk samples from main dairy farms were then analyzed in duplicate by quantitative ELISA for the antibiotics residual levels. The mean residual levels of Gentamicin and Streptomycin were 90 and 80 μg/L, respectively; which are below the allowable maximum residue limit of 200 μg/L as set by the FAO/WHO. Staphylococcus aureus, Listeria monocytogenes, E. coli and total aerobic microorganisms isolated from the milk samples were then tested for resistance against Gentamicin and Streptomycin by the disc agar diffusion method. All the S. aureus, E. coli, and L. monocytogenes isolates showed high resistance to Gentamicin. However, 95% of S. aureus, 60% of E. coli and 58% of L. monocytogenes isolates were resistant to Streptomycin. The obtained results provide evidence that antimicrobial resistant strains of the above pathogens have become remarkably widespread in raw milk. This requires better management for antibiotic usages among livestock farmers to control sources of food contamination and reduce the health risks associated with the development of resistant microbial strains.

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K. Zeina, A. Pamela and S. Fawwak, "Quantification of Antibiotic Residues and Determination of Antimicrobial Resistance Profiles of Microorganisms Isolated from Bovine Milk in Lebanon," Food and Nutrition Sciences, Vol. 4 No. 7A, 2013, pp. 1-9. doi: 10.4236/fns.2013.47A001.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] S. Joshi, “HPLC Separation of Antibiotics Present in Formulated and Unformulated Samples,” Journal of Pharmaceutical and Biomedical Analysis, Vol. 28, No. 5, 2002, pp. 795-809. doi:10.1016/S0731-7085(01)00706-3
[2] M. Choueiri, “Emerging Contaminants in Lebanon: Antibiotic Residues in Cow Manure and Soil,” MS Thesis, American University of Beirut, Beirut, 2008.
[3] W. C. John and E. H. Fred, “Antibiotics: III; Mechanism of Action of Antimicrobial and Antitumor Agents,” Springer-Verlag, New York, 1975.
[4] A. A. Bergwerff and J. Schloesser, “Antibiotics and Drugs Residue Determination,” Encyclopaedia of Food Science, Food Technology and Nutrition, 2003, p. 254.
[5] M. Dubois, D. Fluchard, E. Sior and P. H. Delahaut, “Identification and Quantification of Five Macrolide Antibiotics in Several Tissues, Eggs and Milk by Liquid Chromatography-Electrospray Tandem Mass Spectrometry,” Journal of Chromatography B: Biomedical Sciences and Applications, Vol. 753, No. 2, 2001, pp. 189-202. doi:10.1016/S0378-4347(00)00542-9
[6] The Council of the European Communities, “Council Regulation (EEC) No.2377/90,” Official Journal of the European Communities, No. L 224/P, 1990, pp. 1-8.
[7] Food and Drug Administration, “Tolerances for Residues of New Animal Drugs in Food,” 2008. http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=530.41
[8] K. N. Woodward, “Antibiotics and Drugs Uses in Food Production,” Encyclopedia of Food Science, Food Technology and Nutrition, 1993, p. 249.
[9] F. M. Aarestrup, “Antimicrobial Resistance in Bacteria of Animal Origin,” ASM Press, Washington DC, 2006.
[10] L. Guardabassi, S. Schwarz and D. H. Lloyd, “Pet Animals as Reservoirs of Antimicrobial-Resistant Bacteria,” Journal of Antimicrobial Chemotherapy, Vol. 54, No. 2, 2004, pp. 321-332. doi:10.1093/jac/dkh332
[11] I. Phillips, M. Casewell, T. Cox, B. De Groot, C. Friis, R. Jones, C. Nightingale, R. Preston and J. Waddell, “Does the Use of Antibiotics in Food Animals Pose a Risk to Human Health? A Critical Review of Published Data,” Journal of Antimicrobial Chemotherapy, Vol. 53, No. 1, 2004, pp. 28-52. doi:10.1093/jac/dkg483
[12] D. L. Smith, J. Dushoff and J. G. Morris, “Agricultural Antibiotics and Human Health,” PLoS Medicine, Vol. 2, No. 8, 2005, p. 232. doi:10.1371/journal.pmed.0020232
[13] E. J. Threlfall, “Antimicrobial Drug Resistance in Salmonella: Problems and Perspectives in Foodand WaterBorne Infections,” FEMS Microbiology Reviews, Vol. 26, No. 2, 2002, pp. 141-148.
[14] A. Casadevall, “Crisis in Infectious Diseases: Time for a New Paradigm?” Clinical Infectious Diseases, Vol. 23, No. 4, 1996, pp. 790-794. doi:10.1093/clinids/23.4.790
[15] T. C. Eickhoff, “Antibiotics and Nosocomial Infections,” In: J. V. Bennett and P. S. Brachman, Eds., Hospital Infections, 3rd Edition, Little, Brown and Company, Boston, 1992, pp. 245-264.
[16] J. F. Prescott and J. D. Baggot, “Antimicrobial Therapy in Veterinary Medicine,” Iowa State University Press, Ames, 1993.
[17] F. Peles, M. Wagner, L. Varga, I. Hein, P. Rieck, K. Gutser, P. Keresztúri, G. Kardos, I. Turcsányi, B. Béri and A. Szabó, “Characterization of Staphylococcus aureus Strains Isolated from Bovine Milk in Hungary,” International Journal of Food Microbiology, Vol. 118, No. 2, 2007, pp. 186-193. doi:10.1016/j.ijfoodmicro.2007.07.010
[18] P. M. Griffin and A. V. Tauxe, “The Epidemiology of Infections Caused by Escherichia coli O157:H7, Other Enterohemorrhagic E. coli and the Associated Hemolytic Uremic Syndrome,” Epidemiologic Reviews, Vol. 13, 1991, pp. 60-98.
[19] H. P. R. Seeliger and D. Jones, “Genus Listeria,” In: J. G. Holt, Ed., Bergey’s Manual of Systematic Bacteriology, Vol. 2, 8th Edition, Williams and Wilkins, Baltimore, 1986, pp. 1235-1245.
[20] B.-C. Ye, S. Y. Li, P. Zuo and X.-H. Li, “Simultaneous Detection of Sulfamethazine, Streptomycin, and Tylosin in Milk by Microplate-Array Based SMM-FIA,” Food Chemistry, Vol. 106, No. 2, 2007, pp. 797-803. doi:10.1016/j.foodchem.2007.06.006
[21] H. A. Wallace, G. A. June, P. S. Sherrod, T. S. Hammack and R. M. Amaguana, “Salmonella,” In FDA Bacteriological Analytical Manual, 8th Edition, Washington DC, 1995.
[22] Clinical and Laboratory Standards Institute, “Performance Standards for Antimicrobial Susceptibility Tests,” National Committee for Clinical Laboratory Standards, Wayne, 2009.
[23] C. Chauvin, S. Le Bouquin-Leneveu, A. Hardy, D. Haguet, J. P. Orand and P. Sanders, “An Original System for the Continuous Monitoring of Antimicrobial Use in Poultry Production in France,” Journal of Veterinary Pharmacology and Therapeutics, Vol. 28, No. 6, 2005, pp. 515-523. doi:10.1111/j.1365-2885.2005.00697.x
[24] A. L. Aronson, “Potential Impact of the Use of Antimicrobial Drugs in Farm Animals on Public Health,” Presented at the Meeting on Pharmacology in the Animal Health Sector, Colorado State University, 1975.
[25] H. D. Mercer, “Antimicrobial Drugs in Food Producing Animals,” Veterinary Clinics of North America, Vol. 5, 1977, pp. 3-5.
[26] S. D. Holmberg, M. T. Osterholm, K. A. Senger and M. L. Cohen, “Drug-Resistant Salmonella from Animals Fed Antimicrobials,” New England Journal of Medicine, Vol. 311, No. 10, 1984, pp. 617-622. doi:10.1056/NEJM198409063111001
[27] P. H. Archimbault, “Persistence in Milk of Active Antimicrobial Intramammary Substances. Veterinary Pharmacology and Toxicology,” MTP Press Ltd., Lancaster, 2005.
[28] M. C. Enright, “The Evolution of Resistant Pathogen— The Case of MRSA,” Current Opinion in Pharmacology, Vol. 3, No. 5, 2003, pp. 474-479. doi:10.1016/S1471-4892(03)00109-7
[29] N. H. Kwon, K. T. Park, J. S. Moon, W. K. Jung, S. H. Kim and J. M. Kim, “Staphylococcal Cassette Chromosome Mec (SCCmec) Characterization and Molecular Analysis for Methicillin-Resistant Staphylococcus aureus and Novel SCCmec Subtype IVg Isolated from Bovine Milk in Korea,” Journal of Antimicrobial Chemotherapy, Vol. 56, No. 4, 2005, pp. 624-632. doi:10.1093/jac/dki306
[30] R. O’Mahony, Y. Abbott, F. C. Leonard, B. K. Markey, P. J. Quinn and P. J. Pollock, “Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated from Animals and Veterinary Personnel in Ireland,” Veterinary Microbiology, Vol. 109, No. 3-4, 2005, pp. 285-296. doi:10.1016/j.vetmic.2005.06.003
[31] J. L. Wylie and D. L. Nowicki, “Molecular Epidemiology of Communityand Health Care-Associated MethicillinResistant Staphylococcus aureus in Manitoba, Canada,” Journal of Clinical Microbiology, Vol. 43, No. 6, 2005, pp. 2830-2836. doi:10.1128/JCM.43.6.2830-2836.2005
[32] WHO, “Surveillance for the Prevention and Control of Health Hazards Due to Antibiotic Resistant Enterobacteria,” Technical Report Series 624, 1978.
[33] D. A. Barber, G. Y. Miller and P. E. McNamara, “Models of Antimicrobial Resistance and Food-Borne Illness: Examining Assumptions and Practical Application,” Journal of Food Protection, Vol. 66, No. 4, 2003, pp. 700-709.
[34] The Council of the European Communities, “Council Regulation (EEC) No. 2073/2005,” Official Journal of the European Communities, No. L 338, 2005, pp. 1-26.
[35] G. Normanno, G. La Salandra, A. Dambrosio, N. C. Quaglia, M. Corrente, A. Parisi, G. Santagada, A. Firinu, E. Crisetti and G. V. Celano, “Occurrence, Characterization and Antimicrobial Resistance of Enterotoxigenic Staphylococcus aureus Isolated from Meat and Dairy Products,” International Journal of Food Microbiology, Vol. 115, No. 3, 2007, pp. 290-296. doi:10.1016/j.ijfoodmicro.2006.10.049
[36] M. L. Marco and M. H. J. Wells-Bennik, “Impact of Bacterial Genomics on Determining Quality and Safety in the Dairy Production Chain,” International Dairy Journal, Vol. 18, No. 5, 2008, pp. 486-495.
[37] O. Akineden, C. Annemüller, A. Hassan, C. Lammler, W. Wolter and M. Schock, “Toxin Genes and Other Characteristics of Staphylococcus aureus Isolates from Milk of Cows with Mastitis,” Clinical and Diagnostic Laboratory Immunology, Vol. 8, No. 5, 2001, pp. 959-964.
[38] A. Pengov, C. V. Flajs, T. Zadnik, J. Marinsek and M. Pogacnik, “Distribution of Chloramphenicol Residues in Lactating Cows Following an External Application,” Analytica Chimica Acta, Vol. 529, No. 1-2, 2005, pp. 347-351. doi:10.1016/j.aca.2004.07.035
[39] D. W. Flemming, S. L. Cochi, K. L. Mackonald, J. Brondum, P. S. Hayes and B. D. Plikaytis, “Pasteurised Milk as a Vehicle of Infection in an Outbreak of Listeriosis,” New England Journal of Medicine, Vol. 312, 1985, pp. 404-407. doi:10.1056/NEJM198502143120704
[40] M. J. Linnan, L. Mascola, X. D. Lou, V. Goulet, S. May, C. Salminen, D. W. Hird, M. L. Yonekura, P. Hayes, R. Weaver, A. Audurier, B. D. Plikaytis, S. L. Fannin, A. Kleks and C. V. Broome, “Epidemic Listeriosis Associated with Mexican Style Cheese,” New England Journal of Medicine, Vol. 319, 1988, pp. 823-828. doi:10.1056/NEJM198809293191303
[41] O. Lyytikainen, T. Autio, R. Maijala, P. Ruutu, T. Honkanen-Buzalski and M. Miettinen, “An Outbreak of Listeria Monocytogenes Serotype 3a Infections from Butter in Finland,” Journal of Infectious Diseases, Vol. 181, No. 5, 2000, pp. 1838-1841. doi:10.1086/315453
[42] N. Bemrah, M. Sanaa, M. H. Cassin, M. W. Griffiths and O. Cerf, “Quantitative Risk Assessment of Human Listeriosis from Consumption of Soft Cheese Made from Raw Milk,” Preventive Veterinary Medicine, Vol. 37, No. 1-4, 1998, pp. 129-145. doi:10.1016/S0167-5877(98)00112-3
[43] V. Babak, J. Schlegelova and H. Vlkova, “Interpretation of the Results of Antimicrobial Susceptibility Analysis of Escherichia coli Isolates from Bovine Milk, Meat and Associated Foodstuffs,” Food Microbiology, Vol. 22, No. 4, 2004, pp. 353-358. doi:10.1016/j.fm.2004.08.010
[44] H. Sorum and M. Sunde, “Resistance to Antibiotics in the Normal Flora of Animals,” Veterinary Research, Vol. 32, No. 3-4, 2001, pp. 227-241. doi:10.1051/vetres:2001121
[45] B. Catry, H. Laevens, L. A. Devriese, G. Opsomer and A. de Kruif, “Antimicrobial Resistance in Livestock,” Journal of Veterinary Pharmacology and Therapeutics, Vol. 26, No. 2, 2003, pp. 81-93. doi:10.1046/j.1365-2885.2003.00463.x
[46] H. Oppegaard, T. M. Steinum and Y. Wasteson, “Horizontal Transfer of a Multi-Drug Resistance Plasmid between Coliform Bacteria of Human and Bovine Origin in a Farm Environment,” Applied and Environmental Microbiology, Vol. 67, No. 8, 2001, pp. 3732-3734. doi:10.1128/AEM.67.8.3732-3734.2001
[47] B. R. Berends, A. E. Van den Bogaard, F. Van Knapen and J. M. Snijders, “Human Health Hazards Associated with the Administration of Antimicrobials to Slaughter Animals. Part II. An Assessment of the Risks of Resistant Bacteria in Pigs and Pork,” Veterinary Quarterly, Vol. 23, No. 1, 2001, pp. 10-21. doi:10.1080/01652176.2001.9695069
[48] J. W. Chow, V. Kak, I. You, S. J. Kao, J. Petrin, D. B. Clewell, S. A. Lerner, G. H. Miller and K. J. Shaw, “Aminoglycoside Resistance Genes aph(200)-Ib and aac(60)Im Detected Together in Strains of Both Escherichia coli and Enterococcus faecium,” Antimicrobial Agents and Chemotherapy, Vol. 45, No. 10, 2001, pp. 2691-2694. doi:10.1128/AAC.45.10.2691-2694.2001
[49] S. Magnet and J. S. Blanchard, “Molecular Insights into Aminoglycoside Action and Resistance,” Chemical Reviews, Vol. 105, No. 2, 2005, pp. 477-498. doi:10.1021/cr0301088

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