Campylobacter is a major cause of bacterial foodborne diarrhea worldwide. Consumption of raw or undercooked chicken meat contaminated with Campylobacter is the most common causative agent of human infections. Given the high prevalence of contamination in poultry meat and the recent rise of multi -drug -resistant (MDR) Campylobacter strains, an effective intervention method of reducing bird colonization is needed. In this study, the Campylobacter-specific lytic phage CP6 was isolated from chicken feces. Phage CP6 exhibited a broad host range against different MDR Campylobacter isolates (97.4% of strains were infected). Some biological characteristics were observed, such as a good pH (3-9) stability and moderate temperature tolerance (<50 degree celsius). The com plete genome sequence revealed a linear double -stranded DNA (178,350 bp, group II Campylobacter phage) with 27.51% GC content, including 209 predicted open reading frames, among which only 54 were annotated with known functions. Phylogenetic analysis of the phage major capsid protein demonstrated that phage CP6 was closely related to Campylobacter phage CPt10, CP21, CP20, IBB35, and CP220. CP6 phage exerted good antimicrobial effects on MDR Campylobacter in vitro culture and reduced CFUs of the host cells by up to 1 -log compared with the control in artificially contaminated chicken breast meat. Our findings suggested the potential of CP6 phage as a promising antimicrobial agent for combating MDR Campylobacter in food processing.

The interactions between nucleic acids and nanomaterials have been often utilized to design the electrochemical biosensor due to easy preparation, adsorptive tunability and high sensitivity. In this study, we have prepared a new electrochemical biosensor for Pb2+ detection based on GR5 DNAzyme/Ti3C2Tx Mxenes modified glassy carbon electrode (GR5 DNAzyme/Ti3C2Tx Mxenes-GCE). GR5 DNAzyme is an RNA-cleavage-type DNAzyme that shows high specificity towards Pb2+. With the presence of Pb2+, the cleavage of GR5 DNAzyme is activated at a ribo-adenine (rA) site in the substrate stranded DNA, leading to the unwinding of double-helix structure. This can enhance the adsorptive property of Ti3C2Tx Mxenes toward GR5 DNAzyme, which favors the ion intercalation into the Ti3C2Tx Mxenes and induces the increase of oxidation peak current. Therefore, we have successfully applied GR5 DNAzyme/Ti3C2Tx Mxenes-GCE to detect Pb2+ with a linear range from 0.5 to 32 nM and a detection limit of 0.1 nM. This electrochemical biosensor is simple, sensitive and selective for Pb2+ determination that it should find some potential applications in food safety inspection and environmental monitoring.

BACKGROUND: Free gossypol (FG) and cyclopropenoid fatty acids (CPFAs) are two main natural toxins in cottonseed meal(CSM). The increased yolk elasticity under cold storage conditions is related to the excessive CSM in the feed. However, which toxin caused the increased yolk elasticity is still not clear. RESULTS: Our results show that the addition of FG or CPFA to the diet significantly reduced the egg production and feed conversion ratio. Besides, FG also resulted in a decrease in egg weight. The storage of eggs at 4 °C for four weeks resulted in a significant increase in elasticity and a decrease in the concentration of iron and calcium in the boiled yolks of CPFA and CSM groups when compared to the control. CPFA and CSM supplemented groups also showed an increase in pH and content of water in the yolk. Scanning electron microscopy (SEM) images from the CPFA and CSM groups revealed that the morphology of the vitelline membrane of eggs was characterized by different-sized holes. Furthermore, after four weeks of cold storage, the morphology of the vitelline granules in the CPFA and CSM supplemented groups were damaged; however, there were no significant alterations found in the FG group. CONCLUSION: The main cause of the “sponge-bob egg” effect was the presence of CPFA in cottonseed meal, which causes an increase in permeability of the vitelline membrane in eggs.

This study evaluated the genetic diversity and origin of Daweishan Mini chickens using mtDNA sequence polymorphism. Blood samples from 30 Daweishan Mini chickens were collected. The complete D-loop was PCR amplified, sequenced and compared with the DNA data of five Red Junglefowl (Gallus gallus) subspecies. Eighteen variable sites that defined six haplotypes were observed. The six haplotypes were clustered into four clades (A, B, D and E), of which clade A and B were dominant. Clades Aand B were clustered with G.g. spadiceus, indicating these two clades may have originated from this subspecies. These results show there is diversity in the middle of the mtDNA D-loop, and indicate there are multiple maternal origins for Daweishan Mini chickens. It appears that G.g. spadiceus contributed more to the evolution of the Daweishan Mini chickens breed than the other four subspecies tested here.