Analysis of antibiotic residues in raw and commercial milk in Punjab, India vis‐à‐vis human health risk assessment

Antibiotic residues in milk and dairy products in China: occurrence and human health concerns

Although veterinary antibiotics are essential in preventing and treating clinical diseases in cattle, the frequent use of antibiotics leads to antibiotic residues in milk and dairy products, consequently threatening human health. The massive milk consumption makes it necessary to assess antibiotic pollution and health impact comprehensively. Hence, we conducted a systematic review to evaluate antibiotics in milk and dairy products and their potential health risk. We searched four databases using multiple keyword combinations to retrieve 1582 pieces of literature and finally included eighteen articles to analyze antibiotic residues in milk and dairy products. These studies detected seven antibiotics in different regions of China. Quinolones and β-lactam antibiotics exceeded the MRL for raw and commercial milk. The maximum levels of sulfonamides and tetracyclines were detected in the same raw milk sample, exceeding the MRL. The estimated THQ and HI values in milk and dairy products are less than 1 for adults, indicating negligible noncarcinogenic health risk of antibiotics through consuming milk and dairy products. Children face higher health risks than adults, with the HI and THQ of quinolones exceeding 1. It is worth noting that quinolones accounted for nearly 89% of health risks associated with all antibiotics. Finally, we put forward possible research directions in the future, such as specific health effects of total dietary exposure to low levels of antibiotics. In addition, policymakers should effectively improve this problem from the perspectives of antibiotic use supervision, antibiotic residue analysis in food, and continuous environmental monitoring and control.

Tetracycline residues in fresh dairy milk from three districts in Indonesia: Occurrence and dietary exposure assessment

Background and Aim

Milk can introduce antibiotics into the human diet which poses a public health risk. Therefore, a study to determine the tetracycline residue in dairy milk and its health risk assessment is needed. A cross-sectional study was performed to detect tetracycline residues in fresh dairy milk samples collected from the districts of Malang, Boyolali, and Padang Panjang, Indonesia, and to evaluate dietary exposure to tetracycline residues through milk consumption in 10-12-year-old children and adults.

Materials and Methods

A total of 203 fresh dairy milk samples were collected from local and smallholder dairy cows in Malang, Boyolali, and Padang Panjang in April and August 2018. High-performance liquid chromatography equipped with a photodiode array at 355 and 368 nm was used to detect tetracycline residues. Data were evaluated for dietary exposure assessment.

Results

The results showed that the most common residue found was chlortetracycline (8.37%), followed by tetracycline (7.88%) and oxytetracycline (5.91%) in the concentration range of 14.8-498.4, 11.7-49.4, and 11.6-85.6 ng/g, respectively. Seven (3.45%) samples exceeded the maximum residue limit (MRL) for chlortetracycline. However, neither oxytetracycline nor tetracycline residues exceeded the MRL. The mean concentration of the tetracycline residues was 21.76-137.05 ng/g, resulting in an estimated daily intake of 16.46-172.83 ng/kg body weight/day.

Conclusion

Tetracycline residues were found in almost all milk sampling locations. The highest prevalence and residue concentration were obtained from chlortetracycline. Estimated daily intake of tetracycline through milk by 10-12-year-old children and adult consumers was low and the risk to consumers was negligible.

Inspection of antimicrobial remains in bovine milk in Egypt and Saudi Arabia employing a bacteriological test kit and HPLC-MS/MS with estimation of risk to human health

Veterinary medicine uses antibiotics randomly for treatment and growth promotion. Milk of dairy animals contains substantial quantities of antibiotics that have harmful effects on health. It is therefore necessary to test commercially available milk using immunological, chromatographic, or microbiological methods to confirm the absence of antibiotic residues. This study aims to perform a microbiological test, followed by a quantitative confirmation analysis, on raw milk to assess the presence of antibiotic residues. Tests were conducted on 200 milk samples collected from markets and farms in Saudi Arabia and Egypt. The microbial inhibitor test (Delvotest SP-NT) revealed that 40 samples were positive for antibiotic residues. The positive samples were further tested using liquid chromatography-tandem mass spectrometry (LC-MS/MS) as a confirmatory quantitative test for 29 antibiotics that belong to five groups: tetracyclines, sulfonamides, fluoroquinolones, macrolides, and lactamases. Only four samples tested positive for oxytetracycline residues above the maximum residue limit. Based on these results, researchers suggest a monitoring system that considers both microbial and HPLC-MS/MS methods when detecting antibiotic residues in bovine milk. The analysis of risk to human health revealed that antibiotic residues at the detected levels do not pose any health risks to consumers.

S. M. Montenegro MC, Rodríguez-Díaz JM. Contaminants in the cow's milk we consume? Pasteurization and other technologies in the elimination of contaminants

Cow's milk is currently the most consumed product worldwide. However, due to various direct and indirect contamination sources, different chemical and microbiological contaminants have been found in cow's milk. This review details the main contaminants found in cow's milk, referring to the sources of contamination and their impact on human health. A comparative approach highlights the poor efficacy and effects of the pasteurization process with other methods used in the treatment of cow's milk. Despite pasteurization and related techniques being the most widely applied to date, they have not demonstrated efficacy in eliminating contaminants. New technologies have appeared as alternative treatments to pasteurization. However, in addition to causing physicochemical changes in the raw material, their efficacy is not total in eliminating chemical contaminants, suggesting the need for new research to find a solution that contributes to improving food safety.

Determination of antibiotic residues in bovine milk by HPLC-DAD and assessment of human health risks in Northwestern Himalayan region, India

Antibiotic residues in milk affects economics of dairy industry and poses health risks to consumers. This study aimed to assess health risks associated with presence of antibiotics in 173 raw and pasteurized milk sampled from northwestern Himalayan state of India. The oxytetracycline and amoxicillin were quantitatively analyzed using validated HPLC-DAD. Methods were selective and linear (R² > 0.99) with decision limit and detection capability of 1.4 and 0.9 µg/kg and 2.5 and 1.5 µg/kg for oxytetracycline and amoxicillin, respectively. Recoveries ranged from 88-98% with relative standard deviation < 10%. Oxytetracycline and amoxicillin were detected in 8.1% and 1.2% samples, with 1.7% and 1.2% samples exceeding the tolerance limits, respectively. Health risk assessment revealed that estimated daily intakes of antibiotics through milk were lower than acceptable daily intakes (ADI). However, children might receive 9-21% of determined ADI through milk consumption only. Therefore, continuous, sub-therapeutic and long term exposures of antibiotics can pose health risk to consumers. Hence, current findings elucidate the need for vigilant monitoring of antibiotics accompanied by educational programs to farmers for adopting good husbandry practices and adherence to withdrawal periods to meet the expectations of food safety and safeguarding human health.

SUPPLEMENTARY INFORMATION

The online version of this article contains supplementary material available at (10.1007/s13197-021-04988-8).

Understanding Antibiotic Usage on Small-Scale Dairy Farms in the Indian States of Assam and Haryana Using a Mixed-Methods Approach-Outcomes and Challenges

The use and misuse of antibiotics in both humans and animals contributes to the global emergence of antimicrobial resistant (AMR) bacteria, a threat to public health and infection control. Currently, India is the world’s leading milk producer but antibiotic usage within the dairy sector is poorly regulated. Little data exists reflecting how antibiotics are used on dairy farms, especially on small-scale dairy farms in India. To address this lack of data, a study was carried out on 491 small-scale dairy farms in two Indian states, Assam and Haryana, using a mixed method approach where farmers were interviewed, farms inspected for the presence of antibiotics and milk samples taken to determine antibiotic usage. Usage of antibiotics on farms appeared low only 10% (95% CI 8–13%) of farmers surveyed confirmed using antibiotics in their dairy herds during the last 12 months. Of the farms surveyed, only 8% (6–11%) had milk samples positive for antibiotic residues, namely from the novobiocin, macrolides, and sulphonamide classes of antibiotics. Of the farmers surveyed, only 2% (0.8–3%) had heard of the term “withdrawal period” and 53% (40–65%) failed to describe the term “antibiotic”. While this study clearly highlights a lack of understanding of antibiotics among small-scale dairy farmers, a potential factor in the emergence of AMR bacteria, it also shows that antibiotic usage on these farms is low and that the possible role these farmers play in AMR emergence may be overestimated.

Risk Assessment of Veterinary Drug Residues in Meat Products

With the improvement of the global food safety regulatory system, there is an increasing importance for food safety risk assessment. Veterinary drugs are widely used in poultry and livestock products. The abuse of veterinary drugs seriously threatens human health. This article explains the necessity of risk assessment for veterinary drug residues in meat products, describes the principles and functions of risk assessment, then summarizes the risk assessment process of veterinary drug residues, and then outlines the qualitative and quantitative risk assessment methods used in this field. We propose the establishment of a new meat product safety supervision model with a view to improve the current meat product safety supervision system.