Liliana Longo Borges & Melina Bonato (P&D, ICC Brazil)

In these past years, the concept of Food Safety has become increasingly more evident in the food production, mainly when it is related with the export of products of animal origin, which is a huge challenge to the industries to ensure food safety.

Establishing a link between good quality, nutritional value and food safety is a task that has demanded a lot of research on the part of the industries to ensure public health. Brazil is one the major world producers of meats, exporting to diverse countries, and it is also one of its major consumers, which shows the efficacy of the sanitary standards that act from the field up to the final product.

According to the World Health Organization (WHO), about 600 million, or almost 1 in every 10 people in the world, get sick after consuming contaminated foods. Of these, 420 thousand people die, including 125 thousand children of less than 5 years of age. In Brazil from 2007 to June 2016, 90.5% of the cases of food transmitted diseases were provoked by bacteria, and the most frequently found serotypes were Salmonella ssp (7.5%), followed by Escherichia coli (7.2%) and Staphylococcus aureus (5.8%). It is pertinent to emphasize that the real number of cases may be higher, since the symptoms can be poorly diagnosed and the identification of the etiological agent is not always possible.

Salmonella is one of the primary causes of food intoxications in the world, and salmonellosis is considered a relevant public health problem. Outbreaks are generally associated with the consumption of contaminated meats or eggs. Therefore, offering Salmonella-free foods to end consumers is one of the greater objectives of the food production industry.

Sanitary standards of the MAPA (Ministry of Agriculture, Livestock and Food Supply) for control and monitoring of Salmonella, whose Normative Instruction no. 20 revised and updated in October 2016 increases the pressure on control and inspection by responsible agencies of chickens and turkeys in commercial establishments.  This covers areas from production in the field to cold storage units, with the objective of reducing the predominance of this agent and establishing an adequate level of protection for the consumer. The standard requires laboratory tests that prove the presence of absence of Salmonella spp., Salmonella enteritidis; Salmonella typhimurium; Salmonella gallinarum; Salmonella pullorum, among others.

These actions are of extreme importance for the marketing of products of animal origin because they involve all links of the productive chain ensuring a final quality product.

With the use of antibiotic-free diets and the reduction of use of antibiotic growth promoters,  the implementation of a strict sanitary plan is indispensable because transmission can take place through feed, environment, or even vertical (from the breeder to the chicken / egg-layer), for this reason inadequate management helps in this transmission. There are alternatives to control of Salmonella, like attenuated live vaccines (which generally act on the Salmonella gallinuram and Salmonella typhimurium, which also acts on Salmonella enteritidis), products that act on the feed such as antimicrobial bactericides (normally composed of organic acids), and products that act in the animal organism.

There is a large list of probiotics, organic acids, plant extracts, prebiotics, etc which will act directly on Salmonella or, indirectly, modulating the microbiota and the immune system response, improving intestinal integrity, etc. The yeast cell wall (Saccharomyces cerevisiae) is one of the solutions that can help in the Salmonella control program because it is a natural solution that helps in the reduction of contamination and prevention of the problem.

ICC, which for years has been investing in scientific research for yeast-based solutions and product development, believes that food safety starts from the products used in the field, such as those that comprise the animal diets. Based on this concept, ImmunoWall® standouts among the other products because it is composed of dense cell wall of Saccharomyces cerevisiae with high concentrations of β-Glucans and MOS, resulting in an additive with assurance of results and excellent cost / benefit ratio.

Supplementation with ImmunoWall® ensures that poultry maintain the balance of the intestinal microbiota and show improved immune system response, resulting in the decrease of contamination and transmission of pathogenic bacteria to other body organs. In the study published by Hofacre et al. (2017), for the first time in an in vivo experiment, the efficacy of a yeast derived product was proven in reducing the colonization and presence of Salmonella enteritis (SE) in the ovary and cecum of commercial hens. In table 1, observe that commercial hens contaminated by SE at high dosage and supplemented with ImmunoWall® (0.5 kg/ton) had a reduction of intestinal and ovarian colonization by SE when compared with the control group (at 7 and 14 days after the challenge).

Table 1. Summary of results of the study of Hofacre et al. (2017) on the reduction of contamination of Salmonella enteritidis¹ in commercial hens fed with ImmunoWall®²

Days after challenge	Organ	Control	ImmunoWall®	Reductions
	Ovary
7	Presence SE	41.7%	33.3%	-20%
	MPN/g3	101	100	-90%
14	Presence SE	4.2%	2.1%	-50%
	Cecum
7	Presence SE	97.9%	93.8%	-4.2%
	MPN/g3.4	103 b	102 a	-90%
14	Presence SE	53.2%	47.9%	-10%

¹Infection by Salmonella Enteritidis at 16 weeks of age of chickens (orally, 3.0 x 10⁹ CFU/nalidixic acid-resistant SE chicken). ²ImmunoWall® supplemented since 10 weeks of age at 0.5/ton. ³MPN – most probable number (g of the organ). ⁴Means followed by different letters on the same line, are different between each other through the Mann-Whitney test (P<0.05).

The study conducted by Korver et al. (2015, University of Alberta, Canada – unpublished data), tested in vitro (with content of cecum of healthy roosters) the capacity of ImmunoWall® (0.5 kg/ton) to inhibit SE after 24 and 48 hours from inoculation. The results show that ImmunoWall® was capable of inhibiting 99.99% of the SE after 48 hours when compared to the control group.

The reduction of colonization in the cecum is a critical factor in relation to food safety because it will decrease fecal contamination on the surface of the eggs. After an egg is laid, cooling is started and the bacteria on the surface of the egg penetrate through the shell’s pores; that is, the lesser the contamination of the surface with SE, lesser will be the contamination inside the egg.

A study in broiler chickens by Ferreira et al. (2014) with 3-day old chicks infected with Salmonella heidelberg (SH) showed the efficacy in the reduction of the presence of SH in the groups supplemented with ImmunoWall® (0.5 kg/ton up to 35 days and then dose increase, 2 kg/tom, in the termination diet). SH resulted in high prevalence in the litter during the entire assessed period (100% of samples); however, there was a 50% reduction in SH contamination in the crop and 12.5% reduction in the cecum, when compared with the contaminated control group (Table 2). This reduction in SH contamination in the crop and cecum is important to prevent contamination of the carcass in the processing plants since these organs can break during the process.

Table 2. Summary of results of the study of Ferreira et al. (2014) on the reduction of contamination of Salmonella heidelberg¹ in broiler chickens fed diets with ImmunoWall®²

Re-isolation3	Control	ImmunoWall®4	Reduction
Litter3	91.7%	91.7%	—-
Cecum3	43%	38%	12.5%
Crop3	51%	24%	52.6%

¹Infection by Salmonella hieldeberg at 3 days of age (orally, 3×10⁵ CFU/SH chicken). ²ImmunoWall®® from 11 to 35 days of age at 0.5 kg/ton and from 36 to 42 days at 2 kg/ton). ³Weekly SH re-isolation in the litter, crop and cecum. ⁴Means of weekly re-isolations for presence in the collected samples.

Although intensive poultry production may be a highly challenging environment, producers are the first link of the productive chain, and they must be committed about public health and make food safety a concept related with control and not with combat.  Thus, the concern with the quality of ingredients and additives used in animal feed is a global and irreversible trend, considering that the end consumer is becoming more aware of the relation between “nutrition and health.” ImmunoWall®, aside from being a natural additive, has proven to be a viable solution in low dosages for improving intestinal health and food safety, resulting in an excellent cost / benefit ratio.

References

Almeida, R. Food Safety Brazil. Surtos por Salmonella: dados estatísticos, sintomas e prevenção. [Salmonella outbreaks: statistical data, symptoms and prevention] 2015. Available at:  http://foodsafetybrazil.org/surtos-por-salmonella-dados-estatisticos-sintomas-e-prevencoes/#ixzz4cOfqbQi2

Diário Oficial da União [Brazilian Federal Official Gazette]. Ministério da Agricultura, Pecuária e Abastecimento [Ministry of Agriculture, Livestock and Food Supply]. Secretaria de Defesa Agropecuária, Instrução Normativa No – 20, De 21 de Outubro de 2016. [Secretariat of Agricultural and Livestock Defense, Normative Instruction No. 20, dated October 21, 2016] Seção 1. [Section 1] Page 13. 2016.

Ferreira, A.J.P, et al. Uso da associação de levedura e fonte de nucleotídeos na redução da colonização entérica por Salmonella Hiedelberg em frangos. [Use of combination of yeast and nucleotide source in the reduction of Salmonella Heidelberg enteric colonization in chickens] In: Conferência FACTA 2014 de Ciência e Tecnologia Avícolas, Atibaia. Proceedings…. 2014.

Hofacre, C., et al. Use of a yeast cell wall product in commercial layer feed to reduce S.E. colonization. Proceedings of 66^th Western Poultry Disease Conference, March 2017, Sacramento, CA, p. 76-78, 2017.

Korver,D. et al. Effect of dietary prebiotics on intestinal microbial profiles of laying hens, University of Alberta, Canada, 2015 (unpublished data).

Lobos, F. Conselho Regional de Medicina Veterinária de Alagoas. [Regional Council of Veterinary Medicine of Alagoas] Mapa publica novas regras para controle e monitoria da Salmonella. [MAPA published new rules for control and monitoring of Salmonella] 2016. Available at: http://www.crmv-al.org.br/site/mostraconteudo.aspx?c=388

Ministério da Saúde. [Ministry of Health] Surtos de Doenças Transmitidas por Alimentos no Brasil. [Outbreaks of Food Transmitted Diseases in Brazil] 2016. Available at: http://portalarquivos.saude.gov.br/images/pdf/2016/junho/08/Apresenta—-o-Surtos-DTA-2016.pdf

World Health Organization – WHO. Media Centre, News release. WHO’s first ever global estimates of food borne diseases find children under 5 account for almost one third of deaths. 2015. Available at: http://www.who.int/mediacentre/news/releases/2015/foodborne-disease-estimates/en/