Final report for GNE22-297
Project Information
Salmonella Enteritidis (SE) is a leading foodborne pathogen in the US, with many outbreaks traced back to eggs. Although SE can be vertically transmitted, once laid there are multiple routes by which the pathogen can contaminate eggs. Therefore, decontamination of eggs is critical to promote food safety. One of the simplest on-farm approaches to reduce egg contamination is the prompt collection and refrigeration of eggs. Besides refrigeration, eggs are routinely washed in disinfectant containing water prior to shipping. Despite these strategies, there is a lack of decline in Salmonella outbreaks. Therefore, poultry producers are looking for effective strategies to promote egg safety. In this regard, probiotics are commonly used in poultry production for growth promotion and pre-harvest control of SE. In addition to probiotics, postbiotics (probiotic metabolites) also provide a novel antimicrobial alternative to the control of foodborne pathogens. However, to our knowledge, neither probiotics nor postbiotics have been studied for their ability to control SE on eggs. Hence, we proposed the incorporation of probiotics and postbiotics in wash water to reduce SE contamination on eggs either as a conventional dip or electrostatic spray (ES) application. We expect that the results of the study will help identify different antimicrobial regimens and application modalities that can be tailored to specific production needs to promote the egg industry and public health. The study concluded that both ES and dip applications of coated probiotic and postbiotic washes significantly reduced SE populations on the egg surface and inner shell compared to traditional chlorine treatments. Specifically, coated probiotics applied via ES or dip washing and postbiotics applied as a dip were highly effective in limiting SE trans-shell migration and contamination of the internal contents. Additionally, these treatments-maintained egg quality, as they did not adversely affect weight loss, Haugh unit, shell thickness, or cuticle integrity. The project offers poultry producers a validated, consumer-friendly alternative to chemical washes, enhancing both food safety and product appeal. Overall, it is anticipated that these interventions could be used as part of a multi-hurdle on-farm approach for different farm scales to provide sustained antimicrobial activity against foodborne pathogens on eggs.
The overall objective of the proposed study is to determine the antimicrobial efficacy of select probiotics and postbiotics as an egg wash for controlling SE on eggs. As an alternative to washing eggs using the conventional dip method, our study will also investigate the spray application of probiotics/postbiotics to improve egg safety. Egg washing is a method to reduce pathogen contamination on eggs. However, specific requirements such as warm wash water and warm sanitizing rinse are required according to the USDA egg washing standards. In this regard, probiotic and postbiotic spray application avoids increases in egg temperature that can happen when using warm washes. This treatment would also be a more economical processing method since it would eliminate the cost to heat the wash water or decontaminate the wash water prior to its disposal. Further, probiotic/postbiotic spray has the potential to be an environmentally friendly option and can help reduce water usage on the farm (Russell, 2003). Specifically, in this study, we will use an electrostatic spray applicator to ensure uniform product deposition on the egg surface (Muyyarikkandy and Amalaradjou, 2017). Further, to ensure sustained probiotic viability in significant numbers, probiotic wash solutions will be prepared incorporating protectants, namely gum acacia and inulin.
Our specific objectives for the proposed study are as follows:
- To determine the efficacy of incorporating probiotics in wash water to control SE on shell eggs when applied as an electrostatic spray and conventional dip solution.
- To determine the efficacy of incorporating postbiotics in wash water to control SE on shell eggs when applied as an electrostatic spray and conventional dip solution.
- To determine the effect of the different treatments and treatment modalities on egg quality and cuticle coverage.
References
- Russell SM. The effect of electrolyzed oxidative water applied using electrostatic spraying on pathogenic and indicator bacteria on the surface of eggs. Poultry science. 2003;82(1):158-162. doi: 10.1093/ps/82.1.158.
- Muyyarikkandy MS, Amalaradjou MA. Lactobacillus bulgaricus, Lactobacillus rhamnosus and Lactobacillus paracasei attenuate Salmonella Enteritidis, Salmonella Heidelberg and Salmonella Typhimurium colonization and virulence gene expression in vitro. International journal of molecular sciences. 2017;18(11):2381. doi: 10.3390/ijms18112381.
The overall goal of this study was to develop a probiotic-based, natural and user-friendly strategy to reduce Salmonella contamination and improve egg safety.
Salmonella is a leading food pathogen in the US, with many outbreaks in humans attributed to eggs. In effect, source attribution studies have shown that 53% of all food-borne salmonellosis between 1985 and 2002 were attributed to contaminated eggs (Whiley and Ross, 2015). Further, approximately 35% of these Salmonella outbreaks involved the Northeast (Sher et al., 2021). With specific reference to shell eggs, the outbreak in 2018 led to a recall of 206 million eggs (CDC NORS, 2018). Such incidents lead to huge losses for the egg industry. Thus, the poultry industry is under increasing consumer and regulatory pressure to guarantee food safety (Patterson et al., 2014). Among the different serovars of Salmonella enterica, Salmonella enterica serovar Enteritidis (SE) is the most frequently isolated Salmonella from layer flocks and is most associated with outbreaks traced back to the consumption of shell eggs (Patterson et al., 2014; Denagamage et al., 2015).
Salmonella contamination of eggs can occur via vertical and/or horizontal transmission. In the former instance SE colonization of the hen’s reproductive tract results in egg contamination during its formation (Denagamage et al., 2015). Additionally, once laid, eggs can get contaminated by SE from various environmental sources. Therefore, decontamination of eggs is critical to promote its food safety (Galiş et al., 2013). Hence several physical and chemical methods were evaluated to help control SE on eggs. One of the commonly employed interventions involves egg washing in water containing chemical disinfectants (Al-Ajeeli et al., 2016). However, chemicals tend to damage the cuticle layer of the eggshell which acts as a barrier for pathogens thereby making the egg susceptible to subsequent SE contamination (Gole et al., 2014). In addition, current antimicrobial interventions do not exert sustained protection against contamination that can occur later such as during egg handling, shipping and storage (Whiley and Ross, 2015). Moreover, as reported by the CDC, there is a lack of decline in Salmonella outbreaks associated with eggs (CDC NORS, 2018; Patterson et al., 2014). Thus, there is a need for effective, user friendly and environmentally safe antimicrobial strategies that can be applied by the egg industry.
In this regard, probiotics including lactic acid bacteria (LAB) are ideal candidates to control SE since they occupy the same ecological niche, survive and thrive under similar environmental conditions and can competitively inhibit the pathogen (Kostrzynska and Bachand, 2006). Additionally, use of LAB would provide a protective buffer against contamination during the handling, processing, storage and distribution of eggs. In effect, probiotics are widely used in poultry industry to improve performance and reduce SE in birds (Vilà et al., 2009; Tellez et al., 2012; Tellez et al., 2001). Furthermore, the fermentates produced by probiotics (postbiotics) have been shown to exert antimicrobial properties (Shafipour Yordshahi et al., 2020; Rad et al., 2021). However, little is known about the ability of probiotics and postbiotics to inhibit pathogens on shell eggs. Therefore, we proposed the application of select LAB strains and postbiotics as an electrospray or dip wash to control SE on shell eggs. Overall, we expected that incorporation of probiotics and postbiotics in wash water will help provide a practical and user-friendly solution to the control of SE on eggs.
References
- Whiley H, Ross K. Salmonella and eggs: From production to plate. International journal of environmental research and public health. 2015;12(3):2543-2556. doi: 10.3390/ijerph120302543
- Sher AA, Mustafa BE, Grady SC, Gardiner JC, Saeed AM. Outbreaks of foodborne Salmonella Enteritidis in the United States between 1990 and 2015: An analysis of epidemiological and spatial-temporal trends. International journal of infectious diseases. 2021;105:54-61. doi: 10.1016/j.ijid.2021.02.022.
- CDC NORS. Multistate outbreak of SalmonellaBraenderup infections linked to Rose Acre Farms shell eggs. CDC NORS, 2018 https://www.cdc.gov/salmonella/braenderup-04-18/.
- Patterson PH, Venkitanarayanan K, Kariyawasam S. Introduction: Reducing Salmonella Enteritidis contamination of shell eggs. Journal of applied poultry research. 2014;23(2):323-329. doi: 10.3382/japr.2014-00940.
- Denagamage T, Jayarao B, Patterson P, Wallner-Pendleton E, Kariyawasam S. Risk factors associated with Salmonella in laying hen farms: Systematic review of observational studies. Avian diseases. 2015;59(2):291-302. doi: 10.1637/10997-120214-Reg.
- Galiş AM, Marcq C, Marlier D, et al. Control of Salmonella contamination of shell eggs—Preharvest and postharvest methods: A review. Comprehensive reviews in food science and food safety. 2013;12(2):155-182. doi: 10.1111/1541-4337.12007.
- Al-Ajeeli MN, Taylor TM, Alvarado CZ, Coufal CD. Comparison of eggshell surface sanitization technologies and impacts on consumer acceptability. Poultry science. 2016;95(5):1191-1197. doi: 10.3382/ps/pew014.
- Gole VC, Chousalkar KK, Roberts JR, et al. Effect of egg washing and correlation between eggshell characteristics and egg penetration by various Salmonella Typhimurium strains. PLoS ONE. 2014;9(3):e90987. doi: 10.1371/journal.pone.0090987.
- Kostrzynska M, Bachand A. Use of microbial antagonism to reduce pathogen levels on produce and meat products: A review. Canadian journal of microbiology. 2006;52(11):1017-1026. doi: 10.1139/w06-058.
- Vilà B, Fontgibell A, Badiola I, et al. Reduction of Salmonella enterica Enteritidis colonization and invasion by Bacillus cereus var. toyoi inclusion in poultry feeds. Poultry science. 2009;88(5):975-979. doi: 10.3382/ps.2008-00483.
- Tellez G, Pixley C, Wolfenden RE, Layton SL, Hargis BM. Probiotics/direct fed microbials for Salmonella control in poultry. Food research international. 2012;45(2):628-633. doi: 10.1016/j.foodres.2011.03.047.
- Tellez G, Petrone VM, Escorcia M, Morishita TY, Cobb CW, Villasenor L. Evaluation of avian-specific probiotic and Salmonella Enteritidis, Salmonella Typhimurium, and Salmonella Heidelberg-specific antibodies on cecal colonization and organ invasion of Salmonella Enteritidis in broilers. Journal of food protection. 2001;64(3):287-291. doi: 10.4315/0362-028X-64.3.287.
- Shafipour Yordshahi A, Moradi M, Tajik H, Molaei R. Design and preparation of antimicrobial meat wrapping nanopaper with bacterial cellulose and postbiotics of lactic acid bacteria. International journal of food microbiology. 2020;321:108561. doi: 10.1016/j.ijfoodmicro.2020.108561.
- Rad AH, Hosseini S, Pourjafar H. Postbiotics as dynamic biological molecules for antimicrobial activity: A mini review. Biointerface research in applied chemistry. 2021;12(5):6543-6556. doi: 10.33263/BRIAC125.65436556.
Research
Power analysis: A power analysis was conducted to determine the number of samples required to detect a statistically significant difference in pathogen populations between treatments and controls using the PROC-POWER procedure of SAS version 9.3.
Bacterial cultures: A four-strain mix of Salmonella Enteritidis (SE) consisting of SE-12, SE-21, SE-28, and SE-31 was pre-induced for resistance to 50µg/ml of Nalidixic acid (NA) using standard protocols. Each strain was cultured in 10 mL of tryptic soy broth (TSB) with 50 µg/mL NA (TSB-NA) for 24 h at 37°C. To make the four-strain cocktail (inoculum; 9 log CFU/ml), equal amounts of washed bacterial culture from each strain were combined. The bacterial population in the cocktail was determined by plating appropriate dilutions on Xylose Lysine Dextrose agar with NA (XLD-NA) followed by incubation at 37°C for 24h. For the preparation of coated probiotics, Lactobacillus rhamnosus NRRL-B-442 (LR) and L. paracasei DUP 13076 (LR) were cultured separately in de Mann Rogosa Sharpe broth (MRS), incubated at 37°C for 24h. The overnight cultures were centrifuged at 4,500 X g for 15 mins. Briefly, to prepare coated probiotic wash treatments, the probiotic pellets were reconstituted in sterile potable water (~9 log CFU/ml) containing protectants namely gum acacia (GA) or inulin (IN) for application as an electrostatic spray (ES) or dip wash. The different treatments employed as egg wash consisted of:
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Experimental groups |
Treatments |
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Control |
Water wash |
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Chlorine |
Water containing 200 ppm chlorine |
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Coating control 1 |
Water containing 5% w/v GA (GA) |
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Coating control 2 |
Water containing 5% w/v IN (IN) |
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Coated probiotic 1 |
Water containing LP coated with GA (LPG) |
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Coated probiotic 2 |
Water containing LP coated with IN (LPI) |
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Coated probiotic 3 |
Water containing LR coated with GA (LRG) |
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Coated probiotic 4 |
Water containing LR coated with IN (LRI) |
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Preparation of postbiotics and treatment solutions: Briefly, overnight cultures of LP and LR were centrifuged at 4,500 X g for 15 mins. The supernatant was filter sterilized using a 0.22µm Millipore filter to obtain the postbiotics. The wash treatments included control (just water), MRS control (MRSC – water with 40% v/v MRS), 200 ppm chlorine, water with 40% v/v LP postbiotic (LP) and water with 40% v/v LR postbiotic (LR).
Egg inoculation: Fresh table eggs were procured from the UConn commercial poultry farm. The eggs were spot inoculated with 200 µl of SE cocktail (~8 log CFU/egg). The inoculum was placed evenly on the egg surface and air dried for 2 h at 23°C in a biosafety cabinet. Ten eggs were randomly sampled after air drying to determine the efficiency of inoculation.
Electrostatic spraying/Dipping: Inoculated eggs were subjected to either dip washing or electrospray (ES) washing in a biosafety cabinet. In the spray method, an electrostatic sprayer was used to apply a fine mist of the different treatments (200 µl per egg) onto eggs placed on a tray. The electrostatic charge from the ES sprayer ensures even coverage of treatments across all egg surfaces. In the dip method each inoculated egg was placed in a stomacher bag containing 50 ml of the treatment solutions and placed in a water bath held at 42°C for 3 min. The eggs were allowed to dry for 15 min prior to microbiological analysis and/or stored at 4°C to simulate refrigerated storage. Salmonella and probiotic populations (for the coated probiotic treatments) were enumerated on day 0 (immediately after treatment) and days 3, 7, 14 and 21 of refrigerated storage. Three eggs from each treatment were sampled at each timepoint and the study was repeated three times.
Microbiological analysis: At each sampling time, an egg was individually transferred to a sterile stomacher bag containing 10 ml of neutralizing buffer and hand-rubbed for 1 minute. Appropriate dilutions of the buffer were plated on XLD+NA to enumerate surviving Salmonella populations on the outer shell surface. Similarly, samples were also plated on MRS agar to enumerate probiotic populations. If colonies were not detected by direct plating, the sample was enriched in selenite cysteine broth for 48 h at 37°C, followed by streaking on XLD-NA plates. For the egg contents, the eggs that were washed in the neutralizing broth were disinfected with 70% ethanol for 30 seconds, dried, and cracked open aseptically, and the broken shell and internal contents (yolk + albumen) were collected into separate stomacher bags containing selenite cysteine broth with NA. The bags with the internal contents or shells were homogenized for 1 min in a stomacher. Broken shell samples were processed to enumerate surviving probiotic and Salmonella populations. With the internal contents, homogenized samples were enriched to detect presence/absence of Salmonella in the samples.
Egg quality determination: Three uninoculated eggs from each treatment were sampled at each timepoint (day 0, 7, 14 and 21) and the study was repeated three times. Weight loss (%) of eggs during storage was calculated using the formula [{initial egg weight (g) – egg weight after storage (g)}/initial egg weight (g)] X 100. Haugh unit was calculated using the formula HU=100×log (H+7.57–1.7W0.37), where H is the albumen height (mm), and W is the egg weight (g). Shell thickness was measured at the large end, equatorial region and small end using vernier calipers.
Evaluation of cuticle coverage: For this assay, 1 cm2 eggshell pieces around the equator of the egg were cut and mounted on a 9 mm diameter aluminum stub, sputter coated and examined under a scanning electron microscope. Scoring of the cuticle was done using the following criteria: cuticle score 1 = 90 to 100% cuticle cover, score 2 = 60 to 90% cuticle cover, score 3 = 20 to 60% cuticle cover and score 4 = 0 to 10% cuticle cover.
Electrospray washing with coated probiotics significantly reduced SE population on eggs: Throughout the study, we did not observe any influence of the coatings themselves on SE populations on eggs. SE populations recovered from eggs sprayed with the coating controls (GA and IN) were not significantly different from the control. On day 0, following ES washing we recovered ~4.8 log CFU/egg, ~3.6 log CFU/egg and ~4 log CFU/egg of SE from the egg surface in the control, chlorine and coated probiotic groups, respectively. Although on day 0 ES washing with chlorine was the most effective treatment, we did not observe any significant difference between control and chlorine treated samples through refrigerated storage. However, initial ES washing with coated probiotics led to a sustained reduction in SE populations on egg surface. Especially, with the surface counts, ES application of LPG and LPI reduced SE populations to below detection limit (< 2 log CFU/egg) by day 7 of storage. A similar reduction in SE populations was observed with the internal shell surface. This is significant since SE is well known to translocate into the egg making it unamenable to most antimicrobial treatments. As seen with the egg surface, chlorine treatment was found to be less effective in controlling SE populations beyond day 0. For instance, in the coated probiotic groups (LPG, LPI, LRG, and LRI), SE load on the inner shell surface was ~3 log CFU/egg, ~2.6 log CFU/egg and below detection limits (positive by enrichment) on day 0, 3 and 7, respectively (p ≤0.05). Whereas, with both control and chlorine, we recovered ~4 log, ~3.2 log and ~2.8 log CFU/egg of SE on day 0, 3 and 7, respectively. In both GA and IN groups we recovered ~3.4 log, ~3 log, and ~2.6 log CFU/egg on SE on day 0, 3 and 7, respectively. Further, we did not recover any SE from the internal contents of eggs spray-washed with coated probiotics. Overall, when applied as an ES wash, coated probiotics effectively reduced SE populations on the outer surface, inner shell membrane and in the internal contents when compared to control, chlorine, and coating controls. Besides SE counts, our study also revealed that the coated probiotics LR and LP were able to survive on both outer and inner shell surface at ~3 log CFU/egg throughout the study.
Dip washing with coated probiotics significantly reduced Salmonella populations on eggs: Immediately following dip washing (day 0), we recovered ~5 log CFU/egg and ~4 log CFU/egg of SE from the outer egg surface in the control and chlorine groups, respectively. On the other hand, dip application with coated probiotic containing wash water (LPG/LPI/LRG/LRI) resulted in an initial reduction of ~0.7 - 1 log CFU/egg in surface SE counts compared control (p ≤0.05). On day 3, eggs treated with coated probiotics had significantly lower SE populations, at approximately 2.9 log CFU/egg, compared to eggs treated with chlorine, control, GA, and IN, which had SE populations between ~3.7 to 4.1 log CFU/egg (p ≤0.05). By day 7, SE populations on the egg surface were below detection limits in the coated probiotic groups (LPG/LPI/LRG/LRI) with pathogen recovery observed only after sample enrichment. In contrast, on day 7 of refrigerated storage, eggs in the GA, IN, chlorine, and control groups had surface SE levels of approximately 2.7, 2.8, 2.6, and 2.9 log CFU/egg, respectively (p ≤ 0.05). With reference to SE translocation, we observed significant trans-shell migration of SE into the inner shell surface. For instance, on day 0, we recovered ~3.5 log CFU/egg of SE in the coated probiotic groups, while control, chlorine, GA, and IN groups showed significantly higher SE populations at around 4 log CFU/egg (p ≤0.05). With coated probiotics, as seen with the outer surface counts, we observed significant reductions in SE populations on the inner shell surface through the refrigerated storage period (p ≤0.05). On day 3 and day 7, coated probiotics resulted in ~1 – 0.5 log reduction in SE counts when compared to control, chlorine, GA and IN (p ≤0.05). Further, coated probiotics not only reduced SE populations on the outer and inner shell surfaces but also effectively reduced SE contamination in the internal contents compared to the control, chlorine, and coating controls. Also, as seen with the ES spray, coated probiotics survived in significant numbers on the outer and inner shell surface throughout the study.
Electrospray washing of eggs with postbiotics significantly reduced Salmonella populations on eggs: There was no notable difference in SE reduction following ES washing with water (control) and MRSC. Whereas ES application of postbiotic treatments (LP and LR) significantly reduced SE populations on the eggs surface to ~3.6 log CFU/egg when compared to the control ~5.6 log CFU/egg (p ≤0.05). This reduction in SE was sustained, and by day 7 of refrigerated storage pathogen populations in eggs treated with LP and LR postbiotics were below detection limits (p ≤0.05). However, the control and chlorine groups still had SE recovery of ~2.5 log CFU/egg and ~2.7 log CFU/egg, respectively, on day 7 of refrigerated storage. As with the outer surface, ES washing with postbiotics also led to significant reduction in trans-shell migration of SE into the inner shell surface (p ≤0.05). For instance, with the inner shell surface, control and chlorine treated samples had higher SE population on day 0 with ~3.9 log CFU/egg compared to ~2.8 log CFU/egg recovered from the postbiotic groups (p ≤0.05). By day 7, ES washing with postbiotic reduced SE populations to below detection limits with samples being positive for SE only following enrichment. We also observed a similar reduction in SE populations in the internal contents when compared to control, chlorine and MRSC.
Dip washing with postbiotics significantly reduced Salmonella populations on eggs: On day 0, the control and chlorine-treated groups had ~6 log CFU/egg and ~5 log CFU/egg of SE on the outer egg surface, respectively, while postbiotic treatment reduced SE populations by > 5 log CFU/egg with SE being detected only following sample enrichment (p ≤0.05). Further, we did not recover any SE from the postbiotic-treated samples throughout storage. On the other hand, on day 7, we recovered ~4 log CFU/egg and ~3 log CFU/egg of SE from the control and chlorine groups, respectively (p ≤0.05). Moreover, we continued to recover SE positive samples from the control and chlorine groups until the end of the study. These findings suggest that dipping eggs with postbiotic wash water effectively decreases SE contamination on the outer shell surface (p ≤0.05). Beyond surface decontamination, we also enumerated SE populations in the inner shell surface and internal contents. As with the outer surface, postbiotic dip wash also led to significant reduction in SE populations in the inner shell surface (p ≤0.05). By day 7, SE counts were below detection limits but enrichment positive in both the LP and LR groups, while there was still a recovery of ~3 log CFU/egg of SE in the control and chlorine washed eggs (p ≤0.05). By day 21, we did not recover any Salmonella (negative by enrichment) from the postbiotic treated eggs while control and chlorine continued to test positive for pathogen presence in the internal egg surface. Beyond the outer and inner shell surface, postbiotic dip was also reduced SE presence in the internal contents thereby improving egg safety.
Application of coated probiotics and postbiotics as a dip wash or ES wash did not impact egg quality: Egg quality analysis was conducted to evaluate the potential effects of coated probiotic and postbiotics dip/ES wash treatments on egg quality. The weight loss percentage, which is a critical indicator of egg freshness, was evaluated, with a lower weight loss typically indicating fresher eggs. Shell thickness, an important industrial measure, was evaluated due to its role in preventing bacterial penetration and maintaining egg integrity. The Haugh unit (HU), based on albumen height and egg weight, served as a comprehensive measure of internal egg quality. Higher HU values are usually indicative of thicker albumen and fresher eggs, which corresponds to better egg quality. These parameters collectively provide insights into whether coated probiotic and postbiotics wash treatments lead to improvement, deterioration, or maintenance of overall egg quality. Following evaluation of the different egg quality parameters we observed that application of coated probiotics or postbiotics as a dip/ES wash on eggs did not differ significantly from the control throughout refrigerated storage.
Dip or ES washing of eggs with coated probiotics/postbiotics does not impact cuticle coverage: Adequate cuticle coverage is shown to reduce trans-shell migration of bacteria including Salmonella, thereby reducing the risk for contamination. Hence, in this study, we evaluated the impact of different egg washing methods and treatments on cuticle integrity. Our findings demonstrated that neither dip washing (90% – 99% cuticle coverage), nor ES washing (82% – 93% cuticle coverage) had a significant effect on the cuticle score across all treatment groups (p ≥0.05). This result suggests that the egg-washing methods and treatments (coated probiotics/postbiotics) used in this study did not affect the protective cuticle layer, maintaining its ability to serve as a barrier against bacteria.
Conclusion: This study demonstrated that both electrostatic spray (ES) and dip application of coated probiotic and postbiotic washes significantly reduced Salmonella Enteritidis populations on the egg surface and inner shell surface compared to control and chlorine treatments. Probiotic and postbiotic treatments were particularly effective in limiting trans-shell migration of SE and contamination of the internal contents. Specifically, we observed the coated probiotics were effective when applied either as a dip or electrospray while postbiotics were most effective when applied as a dip wash. Furthermore, neither the washing procedures nor the treatments influenced egg quality parameters, and cuticle coverage. The research indicates that probiotic and postbiotic washes provide a safe and effective method for decreasing SE contamination on eggs while maintaining overall egg quality.
Education & Outreach Activities and Participation Summary
Participation Summary:
The graduate student will worked with Dr. Indu Upadhyaya in conducting the outreach component of the study. The target audience for the outreach objective were poultry producers, researchers, scientists, and poultry extension professionals. A poultry outreach program was organized in CT on April 26, 2023, to share project results and obtain feedback from poultry producers in the state. Topics related to sustainable poultry production, poultry diseases, beneficial bacteria in improving egg safety and future of sustainable poultry production were discussed. A follow-up presentation is planned for the upcoming IPPE annual meeting on January 28-30, 2025, to share project results with extension educators, regulators, industry and academics.
Project Outcomes
Our research addressed the economic, environmental, and social aspects of agricultural sustainability with its application to the control of Salmonella Enteritidis on shell eggs by the use of probiotics and postbiotics.
Economic Benefits: By reducing the need for chemicals like chlorine to decontaminate eggs, the project offers natural alternatives. The potential decrease in Salmonella outbreaks can lead to fewer product recalls and foodborne illnesses, thereby minimizing financial losses for farmers and producers.
Environmental Benefits: The project's reliance on probiotics reduces the environmental footprint associated with chemical disinfectants, which often contribute to environmental pollution. The project encourages the adoption of safe, biodegradable microbial treatments, which reduce toxic byproducts and support more ecologically friendly agriculture practices.
Social Benefits: The adoption of natural treatments aligns with growing consumer demand for clean, chemical-free food products, enhancing trust in food safety and sustainability. For farmers, adopting these innovative interventions improves food safety on farms. Furthermore, reducing the risk of foodborne illness helps protect public health, strengthening the relationship between farmers and consumers.
In conclusion, the project's outcomes contribute to a sustainable agricultural system by offering scalable, eco-friendly, and economically viable alternatives to traditional chemicals, benefiting farmers and the broader food production community.
This project investigated the application of probiotics and postbiotics to enhance food safety by mitigating Salmonella Enteritidis on eggshells. This topic is significant because of consumer demands and regulatory pressures affecting the egg industry. The initiative employs new techniques such as electrostatic spraying to enhance the efficacy of antimicrobial treatments.
This research enhanced our understanding of how coated probiotics and postbiotics might reduce the reliance on chemicals such as chlorine in food safety. This strategy aligns with sustainable agricultural methods, harmonizing consumer safety with the protection of the environment. The project facilitated the acquisition of practical skills in utilizing new technology and performing food safety evaluations.
This study highlights the significance of sustainable measures in egg safety that safeguard public health while preserving the environment. It may impact future careers or investigations in microbiology, food safety, or agricultural sustainability. It may result in increased efforts towards natural biocontrol measures or the application of microbial technologies in food systems.
My research and career goals center on improving sustainable agriculture and food safety, especially with the use of natural approaches like probiotics and postbiotics. I aim to contribute to sustainable food systems by reducing reliance on chemicals in both human and animal food production. With my background in food microbiology and veterinary science, I envision pursuing roles in research and development within the food industry or continuing academic research in sustainable agriculture.