Whole genome sequence analysis of multi-drug resistant and biofilm-forming Staphylococcus haemolyticus isolated from bovine milk

Assessing antibiotic residue presence in Turkey meat: insights from a four-box method analysis

Contemporary poultry farming involves extensive antibiotic use, which could potentially pose health risks to consumers through antibiotic residues in animal-derived food products, especially meat. Recent decisions, particularly the ban on nearly all antibiotic feed additives utilized as growth promoters, have resulted in a decrease in their usage. Nonetheless, their essential role in therapy and their economic value are indisputable. This study evaluated the presence of antibiotic residues in marketed turkey meat using the four-box method. The analyses indicated that, of the 400 samples examined, the overall prevalence of contamination was 65.75%. Among the different types of antibiotics identified in the samples, β-lactam/tetracycline residues were the highest, with a prevalence of 41.44%. The analysis of different sample types revealed significant contamination rates in turkey organs, particularly the liver, with a contamination prevalence of approximately 83.75%, and the wing muscle, 78.75%. Two antibiotic families, β-lactam and tetracycline, were identified in the wing muscle and liver at frequencies of 44.44% and 43.28%, respectively. Regarding cross-contamination, positive samples exhibited contamination concurrently by a specific type of residue, with a notable rate of 58.19%. All analyzed organs exhibited contamination by multiple residue types, with varying contaminants present in different organs. The findings indicated varying detection rates of antibiotic residues in consumed turkey meat. These highlight the excessive use of antibiotics in the poultry industry, increasing consumer exposure to these residues'associated risks. Therefore, it is essential to implement stricter measures and monitoring systems regarding the use of antibiotics in poultry farming.

The change of long tail fibers expanded the host range of a T5-like Salmonella phage and its application in milk

We engineered novel T5-like bacteriophage (phage) with extended host ranges by editing the long-tail fibers (PB3 and PB4) to combat Salmonella Enteritidis. By replacing the long-tail fibers PB3 and PB4 regions of phage PH204 with those from phage SP76, we created phages RPA1 - 3 and RPB1 - 3, which exhibited expanded host ranges, lysing 54 strains compared to the original 30 strains. These phages retained the biological characteristics of PH204, including temperature, pH stability and adsorption rate. In milk, RPA1 - 3 and RPB1 - 3 inhibited Salmonella ZWSA605 growth, reducing bacterial counts to 1.51 log10 CFU/mL and 2.18 log10 CFU/mL after 8 h, respectively. Although the bacteriolytic activity of recombinant phages is lower than that of the parent phage, our findings suggest that these phages hold promise as candidates for future phage biocontrol applications in food.