Assessing antibiotic residues in piglet liver and kidney samples: How to manage the results obtained

Microbiological approaches for mycotoxin decontamination in foods and feeds to enhance food security: a review

Mycotoxins are a major food safety concern due to their impact on human health and the economy. Traditional methods for managing mycotoxin contamination in food are insufficient, particularly when faced with the challenges of co-occurring, modified, and emerging mycotoxins. This review investigates the potential of microbiological decontamination techniques with an emphasis on recent developments in molecular biology, nanotechnology, and artificial intelligence (AI). Investigating mycotoxin-degrading microbes, including their metabolic pathways and enzymatic mechanisms, is key to developing effective strategies against mycotoxin contamination. Advanced technologies like next-generation sequencing, clustered regularly interspaced short palindromic repeats associated protein 9 (CRISPR/Cas9), and nanotechnology enable the engineering, optimization, and validation of crucial decontamination parameters. Furthermore, AI algorithms can predict mycotoxin presence, identify ideal microbial agents, and optimize control conditions. This interdisciplinary approach offers transformative potential for improving mycotoxin decontamination and mitigating its risks in food and feed. The convergence of emerging technologies, such as advancements in molecular biology, nanotechnology, and AI, with microbiological decontamination methods holds immense promise for developing more sustainable and effective approaches to address mycotoxin contamination in the future. This review explores the future of mycotoxin decontamination, emphasizing the need for innovative agricultural practices to ensure food safety and security.

Occurrence, fate and control strategies of heavy metals and antibiotics in livestock manure compost land application: A review

Composting is a sustainable method for managing livestock manure, but the residual heavy metals and antibiotics in the compost pose can pose environmental risks when applied to land. Although many studies focus on occurrence and risk mitigation of heavy metals and antibiotics in manure compost land application, there is a lack of systematic analysis covering the entire chain from source to process and final disposal. Given this, this article provides a comprehensive review of the sources, migration, fate, risk assessment, and risk reduction of heavy metals and antibiotics contamination in land application of livestock manure compost for the first time. The main pollutants of concern are heavy metals, particularly Cu and Zn, and antibiotics such as quinolones, tetracyclines, and sulfonamides. The coexistence of these contaminants can easily trigger co-contamination, threatening soil ecosystems and human health. Risk reduction strategies, emphasizing the use of additives during composting and phytoremediation after land application, are discussed. Challenges remain in understanding the interactions between heavy metals and antibiotics and developing effective strategies for mitigating co-contamination. Furthermore, the paper proposes the future prospects on the interactions study and the simultaneous control strategy of heavy metals and antibiotics contamination. It is expected to promote the whole process management of livestock manure and the control of heavy metal-antibiotic co-contamination in the future.

Copper and Antimicrobial Residues in the Liver and Kidney-Antimicrobial Resistance and Cu Tolerance Unrelated in Escherichia coli from Piglets' Faeces

Antimicrobials, widely used in livestock, have induced the emergence of antimicrobial-resistant bacteria, prompting farmers to explore alternatives like copper. This study aims to determine antimicrobial residues and Cu concentrations in the liver and kidney of piglets and to investigate the correlation between Cu and antimicrobial use and the resistance to Cu and antimicrobials of Escherichia coli isolated from piglets' faeces. Antimicrobial residues were quantified by UHPLC-ToF-MS; Cu was quantified using FAAS; microbiological methods were used for E. coli isolation, CuSO4 minimal inhibitory concentration (MIC), and antimicrobial susceptibility; and to detect genes, Real-Time PCR was used. Cu concentrations and antimicrobial residues in piglet livers and kidneys revealed no significant differences. Antimicrobial residues were detected in a significant number of livers and kidneys. While Cu concentrations in the liver were within adequate ranges, those in the kidney exceeded the recommended levels. E. coli isolates from piglet faeces exhibited high antimicrobial drug resistance (AMR), with no clear link to Cu exposure. The genes copA, pcoA, and pcoD, associated with Cu tolerance, were predominantly found in isolates with a CuSO4 MIC of 8 mM. Cu was not used excessively, suggesting that Cu did not replace antimicrobials. E. coli was mostly resistant to antimicrobials and it was not possible to demonstrate that Cu was the trigger for this resistance. There was no relationship between Cu tolerance and AMR in E. coli isolates. This study highlights the need for further research on the complex interplay between metals, antimicrobials, and bacterial resistance in livestock, impacting 'One Health'.

Antibiotic Residues and Zinc Concentrations in the Livers and Kidneys of Portuguese Piglets-Relationship to Antibiotic and Zinc Resistance in Intestinal Escherichia coli

Metal ions such as zinc and copper have been used as alternatives to antibiotics, to improve animal health and growth rates in pig farming. This study aims to determine antibiotic residues and Zn concentration in piglets' livers (n = 56) and kidneys (n = 60); and to examine the correlation between the use of Zn and antibiotics, and resistance to Zn and antibiotics of Escherichia coli isolated from piglets' faeces (n = 60). Samples were collected from randomly selected healthy piglets (n = 60); antibiotic residues were quantified by ultra-high-performance-liquid-chromatography time-of-flight mass spectrometry (UHPLC-ToF-MS); Zn was quantified using flame atomic absorption spectrometry (FAAS); microbiological methods were used for E. coli isolation, antibiotic susceptibility, and Zn minimal inhibitory concentration; and Real-Time PCR was used for gene detection. The presence of antibiotic residues and Zn concentrations in the liver was found to be negatively correlated, whilst no significant difference was observed in the kidney. In E. coli isolated from piglet faeces considered to be susceptible or multi-drug-resistant, no significant difference was found between Zn concentrations in the liver and in the kidney, which appears to indicate that Zn accumulated in the liver and in the kidney does not promote resistance to antibiotics in E. coli. The isolates showed tolerance to Zn which would suggest that antibiotic resistance and phenotypic tolerance to Zn in these isolates are not related. The genes zitB and zntA associated to Zn tolerance, were predominantly found in the more resistant Zn isolates. The findings provide insights on how Zn use in pig production maintains antibiotic resistance and metal tolerance in bacteria, with implications for One Health.

Highly sensitive and selective detection of amoxicillin using molecularly imprinted ratiometric fluorescent nanosensor based on quantum dots

A dual-emission ratiometric fluorescence sensor (CDs@CdTe@MIP) with a self-calibration function was successfully constructed for AMO detection. In the CDs@CdTe@MIP system, non-imprinted polymer-coated CDs and molecule-imprinted polymer-coated CdTe quantum dots were used as the reference signal and response elements, respectively. The added AMO quenched the fluorescence of the CdTe quantum dots, whereas the fluorescence intensity of the CDs remained almost unchanged. The AMO concentration was monitored using the fluorescence intensity ratio (log(I647/I465)0/(I647/I465)) to reduce interference from the testing environment. The sensor with a low detection limit of 0.15 μg/L enabled detection of the AMO concentration within 6 min. The ratiometric fluorescence sensor was used to detect AMO in spiked pork samples; it exhibited a high recovery efficiency and relative standard deviation (RSD) of 97.94-103.70% and 3.77-4.37%, respectively. The proposed highly sensitive and selective platform opens avenues for sensitive, reliable, and rapid determination of pharmaceuticals in the environment and food safety monitoring using ratiometric sensors.

Tannic acid alleviates ETEC K88-induced intestinal damage through regulating the p62-keap1-Nrf2 and TLR4-NF-κB-NLRP3 pathway in IPEC-J2 cells

BACKGROUND

Tannic acid (TA), a naturally occurring polyphenol, has shown diverse potential in preventing intestinal damage in piglet diarrhea induced by Enterotoxigenic Escherichia coli (ETEC) K88. However, the protective effect of TA on ETEC k88 infection-induced post-weaning diarrhea and its potential mechanism has not been well elucidated. Therefore, an animal trial was carried out to investigate the effects of dietary supplementation with TA on the intestinal diarrhea of weaned piglets challenged with ETEC K88. In addition, porcine intestinal epithelial cells were used as an in vitro model to explore the mechanism through which TA alleviates intestinal oxidative damage and inflammation.

RESULTS

The results indicated that TA supplementation (2 and 4 g kg-1) reduced diarrhea rate, enzyme activity (diamine oxidase [DAO] and Malondialdehyde [MAD]) and serum inflammatory cytokines concentration (TNF-α and IL-1β) (P < 0.05) compared to the Infection group (IG), group in vivo. In vitro, TA treatment effectively alleviated ETEC-induced cytotoxicity, increased the expression of ZO-1, occludin and claudin-1 at both mRNA and protein levels. Moreover, TA pre-treatment increased the activity of antioxidant enzymes (such as T-SOD) and decreased serum cytokine levels (TNF-α and IL-1β). Furthermore, TA increased cellular antioxidant capacity by activating the Nrf2 signaling pathway and decreased inflammatory response by down-regulating the expression of TLR4, MyD88, NF-kB and NLRP3.

CONCLUSION

The present study showed that TA reduced the diarrhea rate of weaned piglets by restoring the intestinal mucosal mechanical barrier function, alleviating oxidative stress and inflammation. The underlying mechanism was achieved by modulating the p62-keap1-Nrf2 and TLR4-NF-κB-NLRP3 pathway. © 2024 Society of Chemical Industry.

Therapeutic effects of lincomycin and level of drug degradation in broiler tissues after treatment

Background and Aim

Lincomycin is an antibiotic used in broiler farming and is commonly combined with other substances to achieve synergistic and complementary effects on the antibacterial spectrum and mechanism. We developed a specific high-performance liquid chromatography (HPLC) method to measure lincomycin levels in broiler tissues. This study aimed to determine the lincomycin level in tissues and compare it with the minimum inhibitory concentration (MIC) and maximum residue limit (MRL) of certain pathogenic bacteria.

Materials and Methods

Three groups of broiler chickens were involved in the study (n = 20 in each group): A control group without lincomycin treatment and two groups (each further divided into two sub-groups) that received oral lincomycin at a dose of 1 g/10 kg of body weight daily for 7 and 14 consecutive days. Tissue samples were collected from each group 1 day and 1 week after lincomycin administration (ALA). This study validated the development of a technique for analyzing drug level degradation in tissues using HPLC. Descriptive and statistical analyses were performed for drug levels to assess their therapeutic value and safety based on lincomycin MIC of certain pathogenic bacteria and MRL.

Results

The method validation resulted in linear regression and coefficient of determination for tissues with r2 > 0.99, with a recovery rate of 90%-110%, precision as the coefficient of variation 15%, and specificity with no peak overlap for lincomycin. The limits of detection for the liver and kidney were 0.01 μg/g, 0.05 μg/g, and 0.1 μg/g for the breast muscle and all tissues. Administration of lincomycin for 7 and 14 days resulted in therapeutic value concentrations. Lincomycin levels in the liver and kidney of ALA exceeded the MRL, whereas breast muscles were below the MRL for a week of ALA treatment.

Conclusion

Administration of lincomycin for 7 and 14 consecutive days resulted in therapeutic value; however, after a week, most tissues showed high drug concentrations that exceeded the MRL. It is necessary to carefully consider the prolonged therapeutic dose of lincomycin in broilers. Antibiotic therapy must be guided in such a way as to protect the product from harmful residues.

Tissue residue distribution and withdrawal time estimation of trimethoprim and sulfachloropyridazine in Yugan black-bone fowl (Gallus gallus domesticus Brisson)

Black-bone fowl are different from ordinary broilers in appearance and are considered to have rich nutritional properties. However, the metabolism of therapeutic drugs in black-bone fowl remains unclear. This study aimed to determine the tissue residue depletion kinetics of trimethoprim and sulfachloropyridazine in Yugan black-bone fowl, after daily oral administrations for 5 days at 4 mg/kg bw/day trimethoprim and 20 mg/kg bw/day sulfachloropyridazine, and to calculate the withdrawal times. After consecutive oral administrations, the tissues (liver, kidney, muscle and skin/fat) were collected at each of the following time points (0.16, 1, 3, 5, 7, 9, 20, 30 and 40 days). A newly-devised LC-MS/MS method was used to analyse the concentrations of trimethoprim and sulfachlorpyridazine in target tissues. The results showed that sulfachloropyridazine was rapidly metabolised in broilers, and there was no residue in all tissues 3 days post-administration. The concentration of trimethoprim in black-bone fowl skin/fat is the highest, and its metabolism rate is low. After 40 days, the concentration of trimethoprim in skin/fat is still as high as 140.1 ± 58.0 μg/kg, exceeding the maximum residue limit. In order to protect consumers' health, it is suggested that the withdrawal time of TMP in Yugan black-bone fowl is 69 days.

Hermetia illucens L. larvae-associated intestinal microbes reduce the transmission risk of zoonotic pathogens in pig manure

Black soldier fly (BSF) larvae are considered a promising biological reactor to convert organic waste and reduce the impact of zoonotic pathogens on the environment. We analysed the effects of BSF larvae on Staphylococcus aureus and Salmonella spp. populations in pig manure (PM), which showed that BSF larvae can significantly reduce the counts of the associated S. aureus and Salmonella spp. Then, using a sterile BSF larval system, we validated the function of BSF larval intestinal microbiota in vivo to suppress pathogens, and lastly, we isolated eight bacterial strains from the BSF larval gut that inhibit S. aureus. Results indicated that functional microbes are essential for BSF larvae to antagonise S. aureus. Moreover, the analysis results of the relationship between the intestinal microbiota and S. aureus and Salmonella spp. showed that Myroides, Tissierella, Oblitimonas, Paenalcalignes, Terrisporobacter, Clostridium, Fastidiosipila, Pseudomonas, Ignatzschineria, Savagea, Moheibacter and Sphingobacterium were negatively correlated with S. aureus and Salmonella. Overall, these results suggested that the potential ability of BSF larvae to inhibit S. aureus and Salmonella spp. present in PM is accomplished primarily by gut‐associated microorganisms.

Occurrence of heavy metals, antibiotics, and antibiotic resistance genes in different kinds of land-applied manure in China

Various pollutants remaining in the livestock and poultry manures pose potential threat to the soil ecosystem during land application, whose impact should be appreciated. The occurrence of heavy metals, antibiotics, and antibiotic resistance genes (ARGs) in swine manure (SM), chicken manure (CM), and the SM organic fertilizer (OF) were investigated. The order of total concentrations of antibiotics detected in manures was as follows: SM > CM > OF. The amount of ciprofloxacin (CIP) in SM reached up to 6.61 mg/kg, which only occupied 1% of the antibiotic concentration reported in the past years. The total concentration of thirteen ARGs in CM ranked first, reaching 7.35 × 10¹¹ copies/g, among which the strB gene was detected with the highest concentration. It was worth noting that the qnr ARGs were persistent in OF with the absence of corresponding antibiotics, indicating ARGs were harder to remove than antibiotics during manure composting. Zn and Cu (46.5-843 mg/kg) were obviously higher than other seven heavy metals, and significantly correlated with most ARGs (p < 0.01). This study provided the basic data of the pollution in animal manures that will be land-applied, illuminating the original source of potential risk in soil ecosystem.