An Alternative Approach Using Nano-garlic Emulsion and its Synergy with Antibiotics for Controlling Biofilm-Producing Multidrug-Resistant Salmonella in Chicken.

Surface-growing antibiotic-resistant pathogenic Salmonella is emerging as a global health challenge due to its high economic loss in the poultry industry. Their pathogenesis, increasing antimicrobial resistance, and biofilm formation make them challenging to treat with traditional therapy. The identification of antimicrobial herbal ingredients may provide valuable solutions to solve this problem. Therefore, our aim is to evaluate the potency of nano garlic as the  alternative of choice against multidrug-resistant (MDR) Salmonella isolates using disc diffusion and microdilution assays. Then, checkerboard titration in trays was applied, and FIC was measured to identify the type of interaction between the two antimicrobials. A disc diffusion assay revealed that neomycin was the drug of choice. The range of nano garlic MIC was 12.5-25 µg/ml, while the neomycin MIC range was 32-64 µg/ml. The FIC index established a synergistic association between the two tested drugs in 85% of isolates. An experimental model was used including nano garlic and neomycin alone and in combination against Salmonella infection. The combination therapy significantly improved body productivity and inhibited biofilm formation by more than 50% down regulating the CsgBAD, motB, and sipA operons, which are responsible for curli fimbriae production and biofilm formation in Salmonella serotypes.

Modulatory Effect of Competitive Exclusion on the Transmission of ESBL E. coli in Chickens.

The extensive use of antimicrobial agents in broiler farms causes the emergence of antimicrobial resistance of E. coli producing severe economic losses to the poultry industry; therefore, monitoring the transmission of ESBL E. coli is of great significance throughout broiler farms. For this reason, we investigated the efficiency of competitive exclusion (CE) products to control the excretion and transmission of ESBL-producing E. coli in broiler chickens. Three hundred samples from 100 broiler chickens were screened for the incidence of E. coli by standard microbiological techniques. The overall isolation percentage was 39% and differentiated serologically into ten different serotypes: O158, O128, O125, O124, O91, O78, O55, O44, O2, and O1. The isolates represented absolute resistance to ampicillin, cefotaxime, and cephalexin. The effectiveness of CE (commercial probiotic product; Gro2MAX) on ESBL-producing E. coli (O78) isolate transmission and excretion was studied in vivo. The results showed that the CE product has interesting properties, making it an excellent candidate for targeted drug delivery by inhibiting bacterial growth and downregulating biofilm, adhesins, and toxin-associated genes loci. The histopathological findings demonstrated the capability of CE in repairing internal organ tissues. Our outcomes suggested that the administration of CE (probiotic products) in broiler farms could be a safe and alternative approach to control the transmission of ESBL-producing virulent E. coli in broiler chickens.