Inactivation of Salmonella Enteritidis on Hatchery and Table Eggs Using a Gas-phase Hydroxyl-Radical Process

Eggs represent a significant vehicle for Salmonella Enteritidis with the pathogen being transferred to chicks in the hatchery, or to consumers via table eggs. In the following, the efficacy of a gas-phase hydroxyl-radical process for decontaminating hatchery and table eggs was evaluated. Recovery of Salmonella was maximized through holding eggs in tryptic soy broth containing 20% w/v glycerol for 1 h prior to plating. By using this technique, it was possible to recover 63% of the theoretical Salmonella inoculated onto eggs. The continuous hydroxyl-radical reactor consisted of a bank of UV-C lamps (254 nm) that generated hydroxyl-radicals from the degradation of hydrogen peroxide (H2O2) mist and ozone gas. The optimal treatment was defined as that which supports a 5 log CFU/egg reduction of Salmonella without negatively affecting egg quality or leaving H2O2 residues. A process of 2% v/v H2O2 delivered at 30 mL/min with a UV-C dose of 19 mJ/cm2 and ozone (20 ppm) with a total treatment time of 10s was selected. The egg quality metrics (Haugh value, yolk index, albumin pH, yolk pH) did not negatively differ over a 35-day shelf-life at 4 or 25℃ compared to washed eggs or nontreated controls. The cuticle layer of eggs remained intact following hydroxyl-radical treatment. Fertilized eggs (n = 61) treated with the hydroxyl-radicals exhibited the same hatchery rate (75%) as nontreated controls (71-79%) with no defects (unhealed navels or red hocks) being observed. The same hydroxyl-radical treatment could be applied to table eggs to support >5 log CFU/egg reduction of Salmonella and was compatible with egg washing regimes practiced in industry. In comparison, the egg washing process based on sodium hydroxide and chlorine supported a 2.76 ± 0.38 log CFU/egg reduction of Salmonella. The hydroxyl-radical treatment represents a preventative control step to reduce the carriage of Salmonella on hatchery and table eggs.

The effects of using UV light instead of formaldehyde in disinfection of hatching eggs on shell microbial load, embryo development, hatchability, and chick characteristics

In this study, it was aimed to determine the effects of using UV light instead of formaldehyde in disinfection of hatching eggs on the microbial load, shell and yolk compositions, embryo development, hatching results and chick characteristics. 552 hatching eggs were divided into formaldehyde fumigation and disinfection with UV groups. After disinfection, bacteriological growth was not observed in groups. While the difference between the groups in terms of hatching results was insignificant, it was determined that the incubation period in the UV group was shorter than that of formaldehyde group. On the hatching day, relative chick weight and weight of bursa Fabricus were found to be higher in the UV group  . UV light can be used as an alternative to formaldehyde as disinfection of hatching eggs because it is easy to use and does not cause any negative effects on egg shell structure, embryo development, hatching results and chick characteristics.

Sodium dichloroisocyanurate: improving broiler health by reducing harmful microbial levels in the waterline

Sodium dichloroisocyanurate (NaDCC) is commonly used for treating drinking water, industrial water, and wastewater. This study aimed to investigate the potential effects of NaDCC-treated waterline drinking water on the growth of AA+ broilers by reducing microbial levels in the waterline. A total of 480 healthy 1-day-old AA+ broilers (46.77 ± 0.50 g) were selected for the experiment and randomly divided into four groups with six replicates of 20 birds each. The control group received regular drinking water, while the test groups received drinking water with NaDCC concentrations of 10, 30, and 50 mg/L. The test groups consumed the treated water on specific days throughout the 42-day experimental period. Results showed that NaDCC treatment significantly reduced the levels of E. coli, Salmonella, S. aureus and Moulds in the drinking water at the waterline (p < 0.05). Drinking water with NaDCC also led to reduced broiler fecal emissions of NH3 and H2S, as well as reduced counts of E. coli, Salmonella, S. aureus and Moulds (p < 0.05), particularly at 30 mg/L and 50 mg/L concentrations. Broilers consuming NaDCC at 50 mg/L exhibited a significant increase in ADG from days 1-42 (p < 0.05). The levels of E. coli, Salmonella, S. aureus and Moulds in the drinking water at the waterline were significantly and positively correlated with the bacterial count in the feces (p < 0.05, R > 0.6). Additionally, bacterial levels in drinking water and broiler feces were negatively correlated with broiler production performance indicators, including ADG, ADFI, F/G and AWC. In conclusion, NaDCC can indirectly enhance broiler performance by reducing the levels of harmful bacteria in the waterline without affecting normal drinking water. The addition of 30 mg/L or 50 mg/L of NaDCC to the waterline in poultry production can effectively control harmful microorganisms and improve poultry health. Based on the experiment's results, it is recommended to preferentially use 30 mg/L NaDCC in the waterline to reduce farming costs.

Holistic Strategies to Control Salmonella Infantis: An Emerging Challenge in the European Broiler Sector

Salmonella spp. has been globally recognized as one of the leading causes of acute human bacterial gastroenteritis resulting from the consumption of animal-derived products. Salmonella Enteritidis, S. Typhimurium, and its monophasic variant are the main serovars responsible for human disease. However, a serovar known as S. Infantis has emerged as the fourth most prevalent serovar associated with human disease. A total of 95% of isolated S. Infantis serovars originate from broilers and their derived products. This serovar is strongly associated with an elevated antimicrobial (AMR) and multidrug resistance, a resistance to disinfectants, an increased tolerance to environmental mercury, a heightened virulence, and an enhanced ability to form biofilms and attach to host cells. Furthermore, this serovar harbors genes that confer resistance to colistin, a last-resort antibiotic in human medicine, and it has the potential to acquire additional transferable AMR against other critically important antimicrobials, posing a new and significant challenge to global public health. This review provides an overview of the current status of the S. Infantis serovar in the poultry sector, focusing on its key virulence factors, including its virulence genes, antimicrobial resistance, and biofilm formation. Additionally, novel holistic strategies for controlling S. Infantis along the entire food chain are presented in this review.

Effects of Sanitizers on Microbiological Control of Hatching Eggshells and Poultry Health during Embryogenesis and Early Stages after Hatching in the Last Decade

Simple Summary

Poultry systems, especially conventional comprehensive production systems to meet the global demand for eggs and meat, are constantly challenged by pathogens, requiring intense sanitary practices. Operations, including the sanitization of hatching eggs, can employ synthetic chemical sanitizers as well as natural plant extracts to minimize the microbial challenge. As the application of formaldehyde sanitizer in hatching eggs cannot be justified in terms of safety for embryonic and human health, studies are underway to assist the industry in adopting new alternative sanitizers. This review aims to evaluate the effects of different sanitizers on the microbiological quality of hatching eggshells and poultry health during embryogenesis and early stages after hatching.

Abstract

The sanitization of hatching eggs is the backbone of the hygienic–sanitary management of eggs on farms and extends to the hatchery. Poultry production gains depend on the benefits of sanitizers. Obtaining the maximum yield from incubation free of toxic sanitizers is a trend in poultry farming, closely following the concerns imposed through scientific research. The toxic characteristics of formaldehyde, the primary sanitizer for hatching eggs, are disappointing, but it is a cheap, practical and widely used antimicrobial. To overcome this shortcoming, multiple synthetic and natural chemical sanitizers have been, and continue to be, tested on hatching eggs. This review aims to evaluate the effects of different sanitizers on the microbiological quality of hatching eggshells and poultry health during embryogenesis and early stages after hatching.

Efficiency of ultraviolet light for disinfection of fertile broiler eggs

ABSTRACT This study aimed to evaluate the effectiveness of ultraviolet light in reducing bacterial load of eggshells and the impact of experimental disinfection on hatching, embryo mortality, and time-borne distribution using broiler breeder hens of different ages (38, 42, and 48 weeks old). Fertile eggs were subjected to different exposure periods (5, 7, and 9 minutes) of UV light (UV-C) with a 254 nm wavelength. For controls, eggs disinfected with paraformaldehyde (5.3 g/m3) and eggs not disinfected (NC). After subjection to disinfection protocols, the eggs were placed into sterile plastic bags containing 20 mL of peptone saline solution (0.1% m:v) and massaged for 1 minute to release the bacterial load. Aliquots of this solution were incubated in specific medium for bacterial growth for 48 hours at 37ºC for subsequent CFU counts. To evaluate the effects of disinfection on production, eggs previously disinfected by UV-C (9 min) and paraformaldehyde and NC eggs were candled between incubation days 10 and 13 and at the end of the incubation period to assess embryonic mortality. Hatchability distribution was performed every 8 hours. The 9 minutes 254nm UV-C light exposure was able to disinfect viable eggs and matched the effectiveness of the paraformaldehyde technique.

Effects of oregano juice on eggshell microbial load, layer embryo development, hatching results, and growth at the first 2 weeks after hatch

One of the factors affecting the hatching results and chick quality is the implementation of an appropriate disinfection program with effective disinfectants. This study was carried out to evaluate the effectiveness of oregano juice as a disinfection of hatching layer eggs as an alternative to formaldehyde. In the study, 1800 eggs collected from 48-week old Akbay white layer breeders were used. Eggs were divided into 3 equal disinfection groups (fumigation with formaldehyde, 50% oregano juice, and 100% oregano juice). In the study, the characteristics of the eggshell, microbial load, embryo development, egg weight loss, hatching results, chick weight and quality, and performance in the first 2 weeks were determined. No differences were observed among the disinfection groups in egg shell characteristics, microbial load in the shell, hatchability of fertile and set eggs, embryonic deaths, and body weight, body weight gain, and feed conversion ratio in female chicks. Egg weight loss was higher (P < 0.001) in the 50% oregano juice group (13.75%) compared to the formaldehyde fumigation group (12.11%). Chick quality score was found to be lower in the formaldehyde fumigation group (96.44) compared to the other two oregano juice groups (P < 0.001). The chicks hatched from the eggs in the formaldehyde fumigation group consumed more feed (119 g/week) in the first 2 weeks (P < 0.001). The use of 50% oregano juice in the disinfection of hatching eggs did not have any negative effects compared to the fumigation process with formaldehyde. Therefore, it is concluded that disinfection with 50% oregano juice was effective in reducing the microbial load in the egg shell as much as formaldehyde fumigation, and even it was superior in chick quality score.

Use of electron irradiation versus formaldehyde fumigation as hatching egg disinfectants - efficacy and impact on hatchability and broiler performance

OBJECTIVE

The use of low-energy electron irradiation for hatching egg disinfection was compared to formaldehyde fumigation.

MATERIAL AND METHODS

To assess the efficacy, eggshells were examined for bacteria before and after disinfection. During incubation, hatching and fattening of 1400 Ross 308 broilers per group candling data, hatching rate, mortality rate and body mass development were recorded to evaluate the impact on health and performance. Additionally, data from the slaughter house and histological evaluation of organ samples were included in the health screening.

RESULTS

Regarding the efficacy, irradiation and formaldehyde significantly reduced the number of bacteria compared to non-disinfected eggs. However, no significant difference was recorded between both treatments. The irradiated group performed better than the reference group concerning the number of infertile eggs, early and late dead embryos and fertile eggs. The performance during fattening was nearly identical in both groups, while mortality differed slightly between the irradiated group and the group treated with formaldehyde. Upon slaughter, there were minor variations concerning the distribution of findings between the groups, but the number of anomalies was not higher than reference values suggest.

CONCLUSION

In both groups no health problems were observed during rearing and the fattening performance met the targets of the manufacturer Aviagen for the used broiler line Ross 308.

CLINICAL RELEVANCE

Lower-energy electron irradiation proves to be an efficient and well-tolerated hatching egg disinfection procedure. Further field trials are necessary to establish low-energy electron irradiation as an alternative to formaldehyde fumigation.

Efficacy of six disinfection methods against extended-spectrum beta-lactamase (ESBL) producing E. coli on eggshells in vitro

The presence of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli on poultry products is an important issue for veterinary and human health due to the zoonotic infection risk for producers and consumers. The present study focuses on testing the efficacy of six different disinfection methods on eggshell samples, aiming to reduce ESBL producing E. coli contamination on the hatching egg. Sterile eggshell cutouts were artificially contaminated with 10⁸ cfu/ml CTX-M-1 producing E. coli and used as a carrier model to analyze the efficacy of six disinfection methods. The contaminated samples were separated into two groups; 1) contaminated and disinfected, 2) contaminated and non-disinfected. Six independent disinfection protocols were performed following product specifications and protocols. Each eggshell sample was separately crushed, and the total viable bacterial count was calculated to determine the disinfection efficacy. Five out of six tested methods (formaldehyde gassing, hydrogen peroxide + alcohol spray, essential oils spray, peracetic acid foam, and low energetic electron radiation) demonstrated a reduction or completely eliminated the initial ESBL producing E. coli contamination. One method (essential oils as cold fog) only partly reached the expected efficacy threshold (reduction of >10² cfu/ml) and the result differed significantly when compared to the reference method i.e. formaldehyde gassing.

Effects of a dry hydrogen peroxide disinfection system used in an egg cooler on hatchability and chick quality

A sanitation method that could continually clean and disinfect the air and surfaces in a hatchery could provide a second layer of microbial reduction on top of routine cleaning and disinfection. A gaseous dry hydrogen peroxide (DHP) system has been used in other facilities for this purpose and could have potential for use in chicken hatcheries. Because the DHP is a true gas and can permeate through the entire hatchery space, contact with eggs during storage and incubation could potentially interfere with normal hatching processes. Therefore, the aim of this study was to evaluate the effects of the DHP system on hatching parameters and chick quality. A total of 3,960 hatching eggs were collected from an ∼40-week-old Ross 308 broiler breeder flock and distributed in 2 treatments: treated and nontreated. For the treated group, the egg cooler was cleaned, and 1 DHP generator was placed inside. Two other DHP generators were placed in the common area outside as well. Both areas were treated for 7 D before placement of eggs, and then eggs were collected and placed inside the cooler over a 4-day period. Eggs were then stored for an additional 3 D after the last collection. Dry hydrogen peroxide levels were recorded each day during storage. For the nontreated group, all DHP machines were removed from the cooler and external room, and the egg cooler was cleaned. Eggs were collected in the same way for the control group as the treated group. After storage, eggs were placed into a single stage Natureform incubator. The eggs exposed to DHP showed higher (P < 0.05) hatchability of fertile eggs and lower (P < 0.05) early embryonic dead than eggs from the nontreated group. No other parameters evaluated were different between groups. Based on this work, the DHP treatment of fertile eggs had no detrimental effect on any performance parameter, with potential positive effects seen on hatch of fertile eggs and early embryonic dead embryos.

Preliminary study: Health and performance assessment in broiler chicks following application of six different hatching egg disinfection protocols

As part of a Germany-wide project that evaluates strategies for the reduction of multi-resistant bacteria along the poultry production chain, the impact of different hatching egg disinfectants on hatchability and health of the broiler chicks was evaluated. Animal trials were conducted with extended-spectrum beta-lactamase- (ESBL) producing Escherichia (E.) coli contaminated hatching eggs and six disinfection protocols that used formaldehyde, hydrogen peroxide, low-energy electron irradiation, peracetic acid and an essential oil preparation. Each protocol was tested on a group of 50 chicks. Equally sized positive and negative control groups were carried along for each trial. Hatchability, mortality and body weight were recorded as performance parameters. During necropsy of half of the animals in each group on day 7 and 14 respectively, macroscopic abnormalities, body weight, weights of liver and gut convolute were recorded and a range of tissue samples for histological examination were collected as part of the health assessment. A decrease in hatchability was recorded for spray application of essential oils. Body weight development was overall comparable, in several groups even superior, to the Ross308 performance objectives, but a reduced performance was seen in the hydrogen peroxide group. Histologically, lymphoid follicles were regularly seen in all sampled organs and no consistent differences were observed between contaminated and non-contaminated groups. Significances were infrequently and inconsistently seen. In conclusion, remarkable findings were a decrease in hatchability caused by the essential oils spray application and a reduced body weight development in the hydrogen peroxide group. Therefore, the essential oils preparation as spray application was deemed inappropriate in practice, while the application of hydrogen peroxide was considered in need of further research. The other trial results indicate that the tested hatching egg disinfectants present a possible alternative to formaldehyde.

Preliminary evaluation of application of a 3-dimensional network structure of siloxanes Dergall preparation on chick embryo development and microbiological status of eggshells

The spatial network structure of Dergall is based on substances nontoxic to humans and the environment which, when applied on solid surfaces, creates a coating that reduces bacterial cell adhesion. The bacteriostatic properties of siloxanes are based on a purely physical action mechanism which excludes development of drug-resistant microorganisms. The aims of the present study were to 1) evaluate a Dergall layer formed on the eggshell surface regarding the potential harmful effects on the chick embryo; 2) evaluate antimicrobial activity and estimate the prolongation time of Dergall's potential antimicrobial activity. Dergall at a concentration of 0.6% formed a layer on the eggshell surface. In vitro testing of the potential harmful effects of Dergall by means of a hen embryo test of the chorioallantoic membrane showed no irritation reaction at a concentration of 3% and lower. The hatchability of the groups sprayed with a Dergall water solution with a concentration of 0 to 5% was 89.1 to 93.8% for fertilized eggs (P > 0.05) but decreased to 63.7% (P < 0.05) in the group sprayed with a 6% concentration of the solution. This phenomenon was caused by embryo mortality in the first week of incubation. At the concentration of 0.6%, Dergall exhibited strong antibacterial properties against bacteria such as Staphylococcus aureus, Escherichia coli, Shigella dysenteriae, Shigella flexneri, and Salmonella typhimurium. For Streptococcus pyogenes, the highest antibacterial activity of Dergall was reported in the concentrations of 100 and 50%. For Pseudomonas aeruginosa, no antibacterial activity of Dergall was generally observed, but in vivo testing showed a strong decrease of all gram-negative bacteria growth. Moreover, a prolonged antimicrobial effect lasting until 3 D after disinfection was observed, which makes Dergall a safe and efficient disinfectant.