Specific pathogen-free(SPF)chickens are widely used in the research of avian diseases and vaccines.Vertically transmissible diseases are transmitted to chickens through vertical transmission,seriously affecting their survival rate,increasing production costs,and causing significant economic losses to the poultry industry,while severely impacting the breeding and use of SPF chickens.Therefore,it is crucial for researchers and managers to enhance their understanding of vertically transmissible pathogens in chickens and to develop effective monitoring measures.Quality monitoring is an important part of ensuring the quality of SPF chickens,with pathogen detection being the primary step.Based on this,it is necessary to cultivate qualified SPF chickens through purification methods and biosecurity measures.This paper reviews the major vertically transmissible pathogens in chickens,including viral pathogens,bacterial pathogens and mycoplasmas,as well as their detection methods.This study compares the differences in microbiological testing items and methods for SPF chickens between the U.S.corporate standard and the Chinese national standard.Analysis of the results shows that in both standards,vertically transmissible pathogens such as Escherichia coli,Proteus mirabilis,Salmonella,and avian leukosis are not included in the microbiological testing items for SPF chickens.Instead,these pathogens are characterized by mixed infections,and outbreaks can seriously affect flock health.To produce higher-quality SPF chickens,it is necessary to include these pathogens in the mandatory testing items.The aim of this paper is to help readers understand the relevant standards for microbiological monitoring of SPF chickens,the hazards of vertically transmissible pathogens,and prevention and control strategies,so as to provide a reference for the detection and purification of pathogens in SPF chickens.

OBJECTIVES: To investigate the synergistic inhibitory effects of AKBA and doxorubicin on malignant phenotype of triple-negative breast cancer (TNBC) MDA-MB-231 cells. METHODS: CCK-8 assay was used to determine the 48-h IC₅₀ of AKBA and doxorubicin in MDA-MB-231 cells, and SynergyFinder was employed to calculate the synergistic index and the optimal concentrations of the two agents. MDA-MB-231 cells treated with AKBA (22.5 μmol/L), doxorubicin (0.84 μmol/L) or their combination were examined for changes in cell proliferation, migration, invasion and apoptosis using Transwell migration, scratch assay, clone generation, RT-qPCR and Western blotting. Network pharmacology analysis was conducted to identify the downstream targets of AKBA in TNBC. In nude mouse models bearing subcutaneous MDA-MB-231 cell xenografts, the effects of normal saline, AKBA (50 mg/kg), doxorubicin (2.5 mg/kg), and AKBA combined with doxorubicin on xenograft growth and histopathology were observed. RESULTS: The IC₅₀ of AKBA and doxorubicin in MDA-MB-231 cells at 48 h was 45.15±0.97 μmol/L and 0.42±0.99 μmol/L, respectively. SynergyFinder confirmed the synergistic effect of AKBA and ADR with a ZIP>10. The combined treatment with AKBA and doxorubicin significantly inhibited the proliferation, migration and invasion, promoted apoptosis of MDA-MB-231 cells, and effectively suppressed xenograft growth in nude mice. Network pharmacology analysis predicted that AKBA affects the progression of TNBC through its downstream target AKBA. CONCLUSIONS AKBA combined with doxorubicin inhibits proliferation, migration and invasion, promotes apoptosis of MDA-MB-231 cells and suppresses MDA-MB-231 cell xenograft growth in nude mice. The combined use of AKBA can attenuate the toxic effects of doxorubicin in nude mice.
Animals ; Doxorubicin/pharmacology* ; Triple Negative Breast Neoplasms/pathology* ; Mice, Nude ; Mice ; Cell Proliferation/drug effects* ; Cell Line, Tumor ; Humans ; Female ; Apoptosis/drug effects* ; Cell Movement/drug effects* ; Xenograft Model Antitumor Assays ; Drug Synergism ; MDA-MB-231 Cells