Beta lactam antibiotics residues in cow's milk: comparison of efficacy of three screening tests used in Bosnia and Herzegovina

Abstract

Beta lactam antibiotics are widely used in therapy of cattle, particularly for the treatment of mastitis. Over 95% of residue testing in dairies in Bosnia and Herzegovina is for Beta lactams. The aim of this paper is to compare the efficacy of three most common screening tests for Beta lactam residues in cow's milk in our country. The tests used in the study are SNAP β Lactam test (Idexx), Rosa Charm β Lactam test and Inhibition MRL test. Study samples included: standardized concentrations of penicillin solution (0, 2, 3, 4, 5 and 6 ppb). In addition we tested milk samples from three equal size study groups (not receiving any antibiotic therapy, treated with Beta lactams for mastitis and treated with Beta lactams for diseases other than mastitis). Sensitivity and specificity were determined for each test, using standard penicillin concentrations with threshold value set at concentration of 4 ppb (Maximum residue level - MLR). Additionally we determined proportions of presumably false negative and false positive results for each test using results of filed samples testing. Agreement of test results for each test pair was assessed through Kappa coefficients interpreted by Landis-Koch scale. Detection level of all tests was shown to be well below MRL. This alongside with effects of natural inhibitors in milk contributed to finding of positive results in untreated and treated animals after the withholding period. Screening tests for beta lactam residues are important tools for ensuring that milk for human consumption is free from antibiotics residues.

Identification and dietary exposure assessment of tetracycline and penicillin residues in fluid milk, yogurt, and labneh: A cross-sectional study in Lebanon

“…Tetracyclines are broad spectrum and the most commonly used antibiotics for prophylactic and growth promotion purposes in many countries around the world, with oxytetracycline (OTC) being one example [8]. In addition to tetracyclines, β-lactam group of antibiotics is widely used in therapy for bacterial infections in cattle, particularly for the treatment of mastitis, the most common disease in adult dairy cows [9,10]. Among antibiotics in this group is penicillin, which is one of the oldest and most widely used antibiotics in the treatment of Gram-positive and Gram-negative bacterial infection in humans and animals [11].…”

Commonly screened antibiotics in raw milk from dairy plants under State Inspection in Rio Grande do Sul, Brazil

“…For example, in the USA, the Pasteurized Milk Ordinance (PMO) emphasizes the test for the presence of antibiotic residues from the betalactam group, and requires sample collection directly in farms or in industrial facilities for the presence of at least six antimicrobials belonging to this group (specifically penicillins, ampicillin, amoxicillin, cloxacillin, cephapirin, and ceftiofur) (FDA, 2015). In Bosnia, 95% of the detection tests used in dairy plants are for screening beta-lactams, considering the broad use of this group of antibiotics to treat mastitis in the herds (FEJZIC et al, 2014). On the other hand, tetracyclines comprise the most used antimicrobials in Africa and, consequently, those antibiotics were the most commonly found in foods of animal origin (DARWISH et al, 2013).…”

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

“…The variations observed could also result from the method of analysis employed by each researcher as each method has its own limitations, also the type of milk examined could also be a contributing factor (Adetunji, 2008). Numerous factors influence the concentration of residues in milk including individual characteristics, health of the animal, amount and type of applied antibiotics, quantity of milk production, method of antibiotic application (Fejzić et al, 2014). The degree of contamination of milk and dairy products with antibiotic residues differs depending on the level of legislation and effectiveness of the methods in different countries (Aalipour et al, 2013).…”