Microfabricated Probiotic Formulation for Inhibition of Salmonella in Poultry

• Author / Creator

  Chopra, Manika

• Salmonella is a major pathogenic bacteria found in both animals and humans. It leads to one of the most common foodborne diseases and is often transmitted to humans through the consumption of animal products. Antibiotics have long been used in the agriculture industry to prevent and treat Salmonella infections, but their use has come under major scrutiny with the recent emergence of antibiotic-resistant bacteria. This has increased the awareness of the benefits of probiotics, especially with regards to their antimicrobial activity. Furthermore, their acceptance as an alternative treatment option to antibiotics is largely due to their natural occurrence in the microbiota of hosts. In this context, and according to current definitions, probiotics must be delivered as “live” cells, which is a significant concern in pharmaceutical industries due to the inherent loss of cells as a result of the harsh conditions of the digestive tract. Often times, formulations will contain larger amounts of cells than effective dose requirements to make up for cells lost during administration, making the process inefficient and increasing costs for manufacturing. In this study, we successfully demonstrated the formulation of a delivery system that protected the viability of the probiotic Lactobacillus acidophilus for application in poultry feed to inhibit Salmonella.
  Micromilling was used to design a delivery system, and micro-mold casting technology was incorporated to fabricate a solid formulation. Process parameters and procedures – such as encapsulation formulation, drying time, and spray coating thickness – were optimized using Sulforhodamine B as a model drug. The protective efficacy and release characteristics of the system with EUDRAGIT® S 100 polymer was determined by conducting in vitro digestive tests using Sulforhodamine B dye. The release rate of encapsulated Sulforhodamine B dye in the optimized system was measured to be 0.251%/ min of exposure to simulated gastric fluid. Only 10 ± 8 % of dye was leaked during incubation in simulated gastric fluid. Successful release of the encapsulated agent was observed upon addition to neutral simulated intestinal fluid, showing the pH responsive abilities of the system. The protein concentration contained in a single patch encapsulating L. acidophilus was determined to be 34.2 ± 13.2 µg. The formulation and S100 polymer showed no negative effects on viability of encapsulated L. acidophilus cells and proved to protect the cells during in vitro tests. More specifically, the cell viability after exposure to harsh digestive conditions was 5.2 times higher, and the inhibition zone against Salmonella was 9.5 % larger with the application of the S100 spray coated polymer. Short term environmental stability tests showed minimal degradation of cells and the protective abilities of the polymer and formulation were once again observed during in vitro studies. Additionally, the S100 polymer likely protected the cells from hydrolytic degradation due to humidity, which could be applied during commercialization stages to fulfill packaging requirements.
  
  This work is the starting point for future developments in micro-fabricated oral drug delivery systems. The unique structure of this system can be further investigated for co-delivery of other agents. Additionally, the formulation could also be optimized to limit the degradation of L. acidophilus cells during long-term storage to improve the efficacy of probiotics and ensure successful commercialization of the system.

• Subjects / Keywords

  • Probiotic

• Graduation date

  Fall 2020

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-2k0t-8n60

• License

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