Therapeutic Effect Of Fermented Chinese Herbal Medicine Instead Of Antibiotics On Chicks Infected With Salmonella Enteritidis

Salmonella enteritidis,a class of foodborne pathogenic bacteria,often spreads among humans,poultry,and wildlife.Salmonella enteritidis infection not only causes human and other animal intestinal infections,sepsis,meningitis,and other diseases,but also predisposes to outbreaks of foodborne disease and persistent infection in animals.Salmonella enteritidis can spread horizontally and vertically in poultry,resulting in reduced immune performance and growth,increased mortality,and contamination of poultryderived foods such as eggs and meat,posing a great threat to human food safety and the modernization of poultry farming.Nowadays,poultry farming tends to be more intensive and large-scale,which creates great opportunities for the spread of Salmonella enteritidis and poses a huge problem for the prevention and control of Salmonella enteritidis.Antibiotics are commonly used in poultry farming and play a very important role in preventing and controlling pathogenic infections and enhancing growth performance of poultry.However,in recent years,the emergence of problems such as drug residues of antibiotics and drugresistant bacteria,the development of alternative antibiotic products has gradually attracted attention.And Fermented Chinese herbal medicine(FCM)have better potential for antibiotic substitution due to their prebiotic efficacy of probiotics and pharmacological effects of Chinese herbs.In this study,we firstly screened 3 safe and high quality probiotics strains from 10 Bacillus strains and 10 Lactobacillus strains.These 3 Bacillus strains have high cellulase activity and xylanase activity,and no hemolytic activity,toxicological genes,less drug resistance and better safety;the 3 Bacillus strains can have good survival rate in the gastrointestinal environment,and have antibacterial activity against Salmonella enteritidis,and the FCM liquid has very sensitive antibacterial activity to Salmonella enteritidis.The results showed that the best conditions for the FCM was to ferment the medium with12.5% herbal medicine addition p H 6 and 4% seed solution,with inoculum for 60 h.After fermentation,the active ingredients of herbal medicine were tested,and the results showed that the increasement of extraction of bitter ginseng alkaloids,chlorogenic acid,baicalin,total flavonoids,protein and total sugar in herbal medicine were 46.51%,76.48% and 18.39%,respectively.76.48%,18.39%,95.91%,507.94% and 197.36%,respectively.The active ingredients in the herbs had better enhancement after fermentation,and the fermentation promoted the release of pharmacological components in the herbs.Using 1-day-old Wuliang Black-bone chicks as experimental animals,the salmonella enteritidis infection model was constructed.The LD50 was used as the infection dose,and FCM and antibiotic ciprofloxacin were used as therapeutic drugs,to investigate the effects of treatment on growth performance,immune performance,serum antioxidant activity,intestinal tissue morphology and intestinal flora of chicks.The results showed that FCM and the antibiotic ciprofloxacin,for the treatment of chicks infected with Salmonella enterica,were able to reduce mortality after infection.By increasing average daily gain(ADG)and average daily feed intake(ADFI),reducing the feed-to-weight ratio(F/G)and mitigating the adverse effects of Salmonella enteritidis infection on the liver,kidneys and lungs,the growth performance of chicks was improved.The immune performance of infected chicks was improved by increasing the activity of superoxide dismutase(SOD)and glutathione peroxidase(GSH-PX)in serum,decreasing the activity of malondialdehyde(MDA)and increasing the index of immune organs.By reducing the abundance of Salmonella enteritidis in the intestinal tract of infected chicks,the damage to the tissue structure of infected chicks could be alleviated.However,the use of antibiotics can reduce the diversity and abundance of bacterial communities in the intestinal tract of chicks,and it can also have a negative impact on the kidney and lung development of chicks.The probiotic efficacy and pharmacological activity of FCM can promote the digestion and absorption capacity and immune performance of chicks,increase the abundance of beneficial bacteria in the intestinal tract,and improve the intestinal health of chicks.In vitro antibacterial experiments and animal experiments showed that FCM have good therapeutic effects on Salmonella enteritidis infection,and it has great potential and feasibility in replacing antibiotics in the treatment of Salmonella enteritidis infection.