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

Abstract

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.

Biodegradation of gentamicin by bacterial consortia AMQD4 in synthetic medium and raw gentamicin sewage

“…Gentamicin is a broad spectrum aminoglycoside antibiotic and China is a country with the largest gentamicin output in the world 1 . By the very nature of the case, a large amount of wastes containing gentamicin produced during gentamicin production and course of practical application in hospital and livestock farm were poured into the environment, which can induce development of gentamicin resistance genes 2 – 4 . The problem of drug resistance could reduce the function of antibiotics.…”

Assessment of microbiological and residual antibiotics status in milk sold in Abeokuta, Ogun State. Nigeria

“…This result is consistent with previous studies in Nigeria by Tona and Olusola, (2014) and Adetunji (2008) in which the highest residue concentration recorded was 0.0080 and 0.0062 mg/Kg respectively. In Lebanon, Kassaify et al (2013) reported the mean residual levels of gentamicin and streptomycin in milk samples to be 90 and 80 µg/Kg respectively. The low concentrations of the tetracycline antibiotics residues observed in this study might be as a result of instability of tetracycline when exposed to heat as recorded by Loksuwan (2002).…”

“…These kinds of foods contaminated with antibiotics residues have significant effects including: allergies and hypersensitivity reactions (Kassaify et al 2013), antibiotic resistance (Chauvin et al, 2005), alteration in intestinal microbiota (Bester and Essack, 2010) and carcinogenicity, (Moreno-bondi et al, 2009). The major worldwide public concern and health hazard associated with antibiotic residues in animal products is the development of resistant bacterial strains of animal origin and its consequent effect on human health (Aarestrup, 2005).…”

Fluorescence polarization assay to detect the presence of traces of ciprofloxacin

“…It is to be noted that the maximum residual limit (MRL) for ciprofloxacin in milk has been fixed at 100 ppb (Council Regulation EEC/2377/90). In Lebanon, few studies have investigated the presence of antibiotic residues in milk [8][9][10] . A recent study showed that ciprofloxacin and oxytetracycline are mostly found antibiotics in milk in Lebanon (personal communication).Currently, laboratory-based methods, such as liquid chromatography-mass spectrometry (LC-MS), high performance liquid chromatography (HPLC) [11][12][13] and microbiological assays 14 are the common used approaches for ciprofloxacin detection.…”

“…It is to be noted that the maximum residual limit (MRL) for ciprofloxacin in milk has been fixed at 100 ppb (Council Regulation EEC/2377/90). In Lebanon, few studies have investigated the presence of antibiotic residues in milk [8][9][10] . A recent study showed that ciprofloxacin and oxytetracycline are mostly found antibiotics in milk in Lebanon (personal communication).…”