Screening, determination and confirmation of tetracycline residues in chicken tissues using four-plate test, ELISA and HPLC-UV methods: comparison between correlation results

In-tube solid phase extraction with graphitic-based polyurethane sponge as a superhydrophobic sorbent and determination of drug residues in foodstuffs using high-performance liquid chromatography

Veterinary drugs used in animal husbandry raise public health concerns due to their residues in the bodies of animals. This study employs a simple and quick sample preparation technique, in-tube solid phase extraction, to extract drug residues from foodstuffs, including eggs, honey, and water. This technique utilizes the synergy of graphitic-based materials and polyurethane sponges (PU) combined through dip coating method to make reusable sorbents for extracting drugs, including amoxicillin, paracetamol, ciprofloxacin, and cefixime. These prepared sorbents were characterized using FTIR, SEM, and XRD. HPLC analysis assessed the extraction efficiency, considering various parameters such as analyte concentration, sample solution pH, extraction time, type of eluting solvent, and graphitic-based polyurethane sponge reusability and stability. The proposed method exhibited a linear response for all three sorbents in the range of 0.03-1000 µg mL-1, with LOD 0.03-1.60 µg mL-1 and LOQ 0.18-4.84 µg mL-1. The % RSD ranged from 1.3 to 9.3 %, with recoveries of up to 98.42 %.

Detection of selected antimicrobial residues in red meat and kidney of beef cattle slaughtered at Nekemte municipal abattoir, Ethiopia

BACKGROUND

Antibiotics are commonly used drugs in farm animals for therapeutic, prophylactic and diagnosis purposes. As a result of the use of antibiotics in livestock, residues of antibiotics may be present in animal-derived foods, especially in meat. This study aimed at determining the antibiotic residues in cattle slaughtered at Nekemte municipal abattoir and assessing the knowledge, attitude and practice (KAP) level of the community about antibiotic residue in food of cattle origin.

MATERIALS AND METHODS

A cross-sectional study was conducted on randomly selected kidney and muscle samples slaughtered at Nekemte municipal abattoir. The samples were collected aseptically and analysed using liquid chromatography mass spectrometer. In addition the KAP of cattle handlers, butcher men and meat users were collected using structured questionnaire. The data was analysed by SPSS and intercooled Stata version 7.0, 2001.

RESULTS

Results are presented as percentages and frequency distributions in tabular and graphical form. From 120 individuals interviewed, only 25.83% knew about withdrawal time and had limited knowledge on effect of antibiotic residue on human health, whereas about 47.5% did not heard about antibiotic residue in meat. Tetracycline was detected in all the sampled meat 60 (100%), whereas oxytetracycline residues were detected in half 15 (50%) of the samples. In the current study doxycycline, sulphadiazine, penicillin G and enrofloxacin were not detected in all samples. Oxytetracycline residue levels ranged from 0.00 to 463.35 µg/kg for the kidney and 0.00 to 354.55 µg/kg for muscle samples. About 10% of kidney and 3.33% muscle samples collected had oxytetracycline residues above maximum residue limits.

CONCLUSION

In general, the study revealed that oxytetracycline residues were prevalent among antimicrobial residues analysed from the study area. The study indicated the presence of high antimicrobial residue and hence exposes for antimicrobial resistance of pathogens warranting coordinated effort to mitigate its health effect on the animal and hence human being.

Evolution of a natural TetR protein and development of a Fe3O4 assisted semi-homogeneous fluorescent method for determination of tetracyclines in milk

Compared with antibody, the recognition spectrum of a receptor is broader, and its recognition ability can be improved using simple mutagenesis technique. Compared with conventional immunoassay, the magnetic bead based immunoassay is simpler and can be recycled. Compared with colorimetric and luminescent immunoassays, fluoroimmunoassay is simpler because it does not require a substrate. So a method combines these merits is desirable. In this study, two amino acids in the binding pocket of a natural Escherichia coli TetR protein were mutated to produce a mutant, and the molecular docking showed the binding energies and the numbers of contact acid for 10 tetracyclines all increased. The mutant was coupled with Fe3O4 to synthesize a magnetic complex, and a fluorescent tracer was synthesized by coupling quantum dot and minocycline with bovine serum albumin. Under the assistance of 96-well bottom magnet, a semi-homogeneous method based on the two materials was developed on conventional microplate for determination of the 10 tetracyclines in milk. Results showed once assay was finished within 20 min, the limits of detection (drug concentration showing 10% inhibition) for the 10 drugs were in the range of 0.32-0.94 ng/mL, and the magnetic complex could be regenerated for 6 times. Furthermore, the sensitivities were improved for 4-6 folds in comparison with the use of natural TetR. Therefore, this method is simple, sensitive, time-saving and recyclable, and it can be used for routine screening of the 10 tetracyclines in milk.

Antimicrobial usage and associated residues and resistance emergence in smallholder beef cattle production systems in Nigeria: A One Health challenge

Livestock intensification has facilitated antimicrobial use (AMU) with consequent antimicrobial resistance (AMR) development. We assessed AMU in beef farms, pathways for residues and resistance dissemination to humans, risk status, residues identification, and drivers for antimicrobial residues and resistance emergence in beef cattle production systems. A cross-sectional survey was conducted in randomly selected beef farms of Northern Nigeria, between 2018 and 2019. Traffic Light model and Disc Diffusion Test were used to assess risk status and determined residues, respectively. Data was analyzed using descriptive statistics and logistic regression models at 95% confidence level. About 92% (n = 608) farmers participated. The majority of farmers managing intensive (78.9%) and semi-intensive (76.6%) farms did not follow antimicrobial dosage instructions. Also, 72.4% and 83.9% of the farmers on intensive and semi-intensive systems, respectively, did not observed withdrawal periods after AMU. Furthermore, 71.5% farmers in intensive and 53.2% in semi-intensive farms used antimicrobials as growth promoters. Antimicrobials frequently used include tetracyclines, sulfonamides and penicillin. Antimicrobial residues and resistance dissemination pathways from beef herds were: consumption of contaminated meat with residues (p = 0.007); contacts with contaminated cattle and fomites (p < 0.001); and contaminated manure and aerosols in farm environment (p = 0.003). Significant drivers of residues and resistance emergence were antimicrobial misuse and overuse (OR = 2.72; 95% CI:1.93-3.83), non-enforcement of laws (OR = 2.98; 95% CI:2.11-4.21), poor education and expertise (OR = 1.52; 95% CI:1.09-2.12), and husbandry management system (OR = 10.24; 95% CI:6.75-15.54). The majority of intensive (63.6%) and semi-intensive (57.63%) farm systems belonged to Class 3 (Red risk) status. Antimicrobial residues were detected in 48.4% intensively and 34.4% semi-intensively managed farms. The study revealed poor practices of AMU in beef cattle production. Many factors were found to influenced antimicrobial residues and resistance occurrence and dissemination. A 'One Health' approach mitigation with adequate sanitation, hygiene, and good biosecurity measures will assure food safety, public and environmental health.

Depletion of Amoxicillin Residue in Edible Tissue of Broiler Chicken by Different Cooking Methods

A new simple isocratic, RP-HPLC method, was developed and validated to estimate amoxicillin (Amox) residue depletion caused by different cooking methods in broiler chicken tissue. The limit of detection (LOD) and the limit of quantitation (LOQ) were 1.32 and 4.00 µg mL⁻¹, respectively. The calibration plot was linear over the concentration range of 0.05–250 µg mL⁻¹, and the relative standard deviation (RSD) values were less than 8%. The effects of various cooking methods (boiling, pan-frying, and microwaving) on residues of Amox were conducted under different combinations of temperature and time. Moreover, the heat stability of Amox standard solutions under boiling water and cooking oil at 100°C was investigated. Amox remained stable for 5–15 min in boiling water, the concentration was significantly reduced in the range of 70–87%, and additional new peaks of the degraded compounds appeared at 30–45 min. In pan-frying, the residue remained stable for 15 min at 100°C and then depleted to 81–92% after 30–45 min. Due to dehydration, the residue concentration showed an increment from 101 to 112% at 150°C. The total decomposition of Amox was observed at 200°C, 30–45 min due to high temperature and long-time effects. In microwave cooking using 500 W, 0.5–2 min, the depletion was insignificant. This study shows that sufficient cooking temperature and time can have a significant effect on the depletion of Amox residues.

Determination of Tetracycline Residues in Kidney and Muscle of Beef Cattle Slaughtered in Dire Dawa and Harar Municipal Abattoirs, Eastern Ethiopia

Background

Antibiotics are among the most widely used drugs in farm animals for therapeutic and prophylactic purposes. However, the antibiotic residues in meat are a serious public health concern due to their harmful effects on consumer health. Besides this problem, there is limited information on the level of the antibiotic residues, including tetracycline residues. Therefore, this study was aimed to determine the tetracycline residues in the kidney and muscle samples of beef cattle in Harar town and Dire Dawa city.

Methods

A study was conducted on 500 randomly selected carcass (250 kidney and 250 muscle samples) slaughtered at Dire Dawa and Harar municipal slaughterhouses between December 2018 and December 2019. The samples were collected aseptically and screened for tetracycline residues by thin layer chromatography. Then, presumptive positive samples were analyzed using high-performance liquid chromatography to get a quantitative outcome. Descriptive statistics were used to determine the frequency, mean, or standard deviation to determine the summary values and distribution of the outcomes. Finally, the data was analyzed using SPSS version 21 software.

Results

Out of 500 samples, oxytetracycline residues were detected in 84% of the samples. However, tetracycline and doxycycline were not detected in all samples. Among the kidney and muscle samples collected from Dire Dawa and Harar abattoirs, 109 (87.2%) and 101 (80.8%) were positive for oxytetracycline, respectively. Oxytetracycline residue levels in Dire Dawa ranged from 57 to 607 µg/kg for the kidney and 10.14 to 435 µg/kg for muscle samples. Among the samples collected from Harar, the concentration of oxytetracycline residues ranged from 16 to 433 µg/kg and 6 to 435 µg/kg for kidney and muscle samples, respectively, at Harar slaughterhouses. About 22.0% of muscle samples collected from Dire Dawa and 17.8% from Harar town had oxytetracycline residues above maximum residue limits.

Conclusions

In general, the study revealed that oxytetracycline residues were prevalent among tetracycline residues analyzed from kidney and muscle samples in the study areas. Thus, there is a risk of consumer exposure to these antibiotic residues that may have human health effects. Therefore, awareness creation and strict regulation is needed by the regulatory authorities for the use of antimicrobial drugs in the livestock industry.

Antibiotic residues in poultry tissues in Iran: A systematic review and meta-analysis

To control the drug residues in foods, the national Maximum Residue Limits (MRLs) have been determined by the international organizations; however, no regulation has been complied for MRL in food animals in Iran. This study was a systematic review and meta-analysis about studies of antibiotic residues in slaughtered poultry carcasses, in Iran. The information was first collected and analyzed throughout six international databases, and four Iranian national databases. According to the data, the total prevalence of antibiotic residues was obtained as 39.41%, 5.40%, and 0.30% using four-plate test (FPT), High-Performance Liquid Chromatography (HPLC), and Enzyme-linked immuno_sorbent assay (ELISA) methods, respectively. The highest prevalence of the residues was shown in the liver by both methods of HPLC (47.75%) and ELISA (14.35%). Moreover, the total mean of antibiotics was recorded as 71.03 ppb and 65.86 ppb in different tissues using the HPLC and ELISA method, respectively. Based on this study, we can conclude that the prevalence of antibiotic residue in poultry meat in Iran is high and that this level does not cause health problems for consumers. It is highly recommended to execute tight surveillance strategies from the government in antibiotic monitoring.

Occurrence and Concentrations of Residues of Tetracyclines, Polyether Ionophores, and Anthelmintics in Livers of Chickens Sold in the Informal Market in Gauteng Province, South Africa

ABSTRACT

The occurrence, concentrations, and variables associated with tetracycline, polyether ionophore, and anthelmintic residues in the livers of chickens sold in the informal market in South Africa were determined. Ultrahigh-performance liquid chromatography-tandem mass spectrometry was used to simultaneously analyze for four tetracyclines, five polyether ionophores, and six anthelmintic residues. The study determined the presence of residues in liver samples at both the limit of quantifications (LOQ) and concentrations over the maximum residue limit (MRL), i.e., noncompliant. Doxycycline (tetracycline group) was detected in 24 (24.5%) of 98 chicken livers, and 15 (15.3%) of the 98 were noncompliant. Mean ± standard deviation (SD) concentrations of 919.04 ± 1,081.30 ppb (LOQ) and 1,410.57 ± 108.89 ppb (MRL) were obtained. Maduramicin was detected in 27 (27.6%) of 98 chicken livers, and 19 (19.4%) of 98 were noncompliant. The mean ± SD for LOQ was 117.96 ± 84.56 ppb, and MRL was 153.21 ± 76.29 ppb. The concentrations of residues of doxycycline and maduramicin in chicken livers varied significantly across townships. Lasalocid was found in 31 (31.6%) of 98 samples, of which 5 (5.1%) had concentrations above the MRL. The mean ± SD concentration of lasalocid was 62.90 ± 170.84 ppb for samples in which lasalocid was quantified and 310.16 ± 356.68 ppb for noncompliant samples. Detectable concentrations of praziquantel, closantel, and rafoxanide (anthelmintics) residues were found in 3 (3.1%), 1 (1.0%), and 2 (2.0%) of 98 chicken livers, respectively. The presence of residues of three classes of veterinary drugs in chicken livers poses food safety implications to consumers and indicates a need for enhanced regulatory enforcement in controlling these drugs in South Africa.

Detection of Bacterial Pathogens and Antibiotic Residues in Chicken Meat: A Review

Detection of pathogenic microbes as well as antibiotic residues in food animals, especially in chicken, has become a matter of food security worldwide. The association of various pathogenic bacteria in different diseases and selective pressure induced by accumulated antibiotic residue to develop antibiotic resistance is also emerging as the threat to human health. These challenges have made the containment of pathogenic bacteria and early detection of antibiotic residue highly crucial for robust and precise detection. However, the traditional culture-based approaches are well-comprehended for identifying microbes. Nevertheless, because they are inadequate, time-consuming and laborious, these conventional methods are not predominantly used. Therefore, it has become essential to explore alternatives for the easy and robust detection of pathogenic microbes and antibiotic residue in the food source. Presently, different monitoring, as well as detection techniques like PCR-based, assay (nucleic acid)-based, enzyme-linked immunosorbent assays (ELISA)-based, aptamer-based, biosensor-based, matrix-assisted laser desorption/ionization-time of flight mass spectrometry-based and electronic nose-based methods, have been developed for detecting the presence of bacterial contaminants and antibiotic residues. The current review intends to summarize the different techniques and underline the potential of every method used for the detection of bacterial pathogens and antibiotic residue in chicken meat.

Assessing Antibiotic Residues in Poultry Eggs from Backyard Production Systems in Chile, First Approach to a Non-Addressed Issue in Farm Animals

Eggs are the main product generated from backyard poultry production systems (BPS) because they can quickly be consumed and sold to meet essential family needs. Nevertheless, antimicrobial residues can accumulate in this product. The objective of this study was to evaluate the presence of antimicrobial residues in eggs produced by poultry kept in BPS in central Chile. To assess this, eggs were obtained from 83 BPS and analysed to evaluate the presence of antibiotic residues (families: tetracyclines, beta-lactams, aminoglycosides and macrolides), using a Four-Plate Test screening method for the detection, based on a bacterial growth inhibition method. Results show a lack of biosecurity procedures at BPS level, making these systems susceptible to the dissemination of antimicrobial residues. These include intensive animal production units in the proximity, and the presence of shared watercourses with other farms. Furthermore, 66% of the surveyed owners are indicated as giving pharmacological treatments to their chickens. Eggs from 61 BPS were positive for at least one antimicrobial. Fifty-three BPS were positive for more than one antimicrobial, and one BPS was positive for all four antimicrobials tested. Consequently, there is a risk that poultry eggs produced in BPS in central Chile carry residues of different families of antimicrobials.

Gold nanostars-enhanced Raman fingerprint strip for rapid detection of trace tetracycline in water samples

Rapid and accurate detection of antibiotics at trace levels in food represents a great challenge. Tetracycline (TC), as a sort of broad-spectrum antibiotic, has been extensively used in animal infection therapy and animal husbandry as growth promoters. Large amounts of TC residues in animal-derived foods affect food quality and safety, and cause undesirable side effects such as allergic reactions and bacterial antibiotic resistance. Here, a Raman fingerprint strip sensor was reported based on surface-enhanced Raman scattering technology and demonstrated for ultrasensitive detection of TC. In this approach, 4-aminothiophenol (4-ATP) modified gold nanostars (GNSs) were used as a strong Raman reporter, which was coated with anti-TC monoclonal antibody serving as a biorecognition to acquire both visual and Raman signals on the test line. To demonstrate the performance of this strip, TC standard solutions with concentrations ranging from 0.5 to 50 ng/mL was detected, the limit of the detection (LOD) for the Raman signal was 0.04 ng/mL, which was 100 times more sensitive than those of color intensity quantifications. The other analogues, oxytetracycline, and chlortetracycline were detected using this method, making them suitable for the samples with TC analogues screening.

Monitoring and risk assessment of tetracycline residues in foods of animal origin

A total of 450 samples consisting of red meat, poultry meat, aquatic product and raw milk were collected during winter 2016 and summer 2017. 22.2% (100/450) of collected meat and raw milk samples were found to be contaminated with antibiotic residues in the initial screening using Premi^®test. According to the enzyme linked immunosorbent assay (ELISA) results, the mean tetracyclines (TCs) concentration of meat samples determined as follows: chicken (155.41 µg/kg) > turkey (138.68 µg/kg) > quail (130.7 µg/kg) > cow (108.92 µg/kg) > calf (105.18 µg/kg) > goat (99.4 µg/kg) > sheep (95.22 µg/kg) > rainbow trout (35.62 µg/kg) > shrimp (31.80 µg/kg). The content of TCs in cow, goat and sheep milk samples were found to be ranged 45.6-163.5 µg/L, 72.4-101.1 µg/L and 65.5-98.9 µg/L, respectively. 5.7% (26/450) of samples had TCs confirmed the ELISA results using high performance liquid chromatography coupled with ultra-violet detection, although the concentration of TCs residues in samples was higher than that of ELISA.

Magnetic solid phase extraction based on graphene oxide/nanoscale zero-valent iron for the determination of tetracyclines in water and milk by using HPLC-MS/MS

A magnetic solid-phase extraction (MSPE) based on graphene oxide/nanoscale zero-valent iron (GO/nZVI) coupled with HPLC-MS/MS was proposed for the determination of trace tetracycline antibiotics (TCs) in water and milk.