Salmonella Typhimurium ST313 isolated in Brazil revealed to be more invasive and inflammatory in murine colon compared to ST19 strains.

Salmonella Typhimurium (ST313) has caused an epidemic of invasive disease in sub-Saharan Africa and has been recently identified in Brazil. As the virulence of this ST is poorly understood, the present study aimed to (i) perform the RNA-seq in vitro of S. Typhimurium STm30 (ST313) grown in Luria-Bertani medium at 37°C; (ii) compare it with the RNA-seq of the S. Typhimurium SL1344 (ST19) and S. Typhimurium STm11 (ST19) strains under the same growing conditions; and (iii) examine the colonization capacity and expression of virulence genes and cytokines in murine colon. The STm30 (ST313) strain exhibited stronger virulence and was associated with a more inflammatory profile than the strains SL1344 (ST19) and STm11 (ST19), as demonstrated by transcriptome and in vivo assay. The expression levels of the hilA, sopD2, pipB, and ssaS virulence genes, other Salmonella pathogenicity islands SPI-1 and SPI-2 genes or effectors, and genes of the cytokines IL-1ß, IFN-γ, TNF-α, IL-6, IL-17, IL-22, and IL-12 were increased during ST313 infection in C57BL/6J mice. In conclusion, S. Typhimurium STm30 (ST313) isolated from human feces in Brazil express higher levels of pathogenesis-related genes at 37°C and has stronger colonization and invasion capacity in murine colon due to its high expression levels of virulence genes, when compared with the S. Typhimurium SL1344 (ST19) and STm11 (ST19) strains. STm30 (ST313) also induces stronger expression of pro-inflammatory cytokines in this organ, suggesting that it causes more extensive tissue damage.

Probiotic Bacteria and Their Cell Walls Induce Th1-Type Immunity Against Salmonella Typhimurium Challenge.

Probiotics have been associated with a variety of health benefits. They can act as adjuvant to enhance specific immune response. Bacterial cell wall (CW) molecules are key structures that interact with host receptors promoting probiotic effects. The adjuvant capacity underlying this sub-cellular fraction purified from Lactobacillus casei CRL431 and L. paracasei CNCMI-1518 remains to be characterized. We interrogated the molecular and cellular events after oral feeding with probiotic-derived CW in addition to heat-inactivated Salmonella Typhimurium and their subsequent protective capacity against S. Typhimurium challenge. Intact probiotic bacteria were orally administered for comparison. We find that previous oral feeding with probiotics or their sub-cellular fraction reduce bacterial burden in spleen and liver after Salmonella challenge. Antibody responses after pathogen challenge were negligible, characterized by not major changes in the antibody-mediated phagocytic activity, and in the levels of total and Salmonella-specific intestinal sIgA and serum IgG, respectively. Conversely, the beneficial effect of probiotic-derived CW after S. Typhimurium challenge were ascribed to a Th1-type cell-mediated immunity which was characterized by augmentation of the delayed-type hypersensitivity response. The cell-mediated immunity associated with the oral feeding with probiotic-derived CW was accompanied with a Th1-cell polarizing cytokines, distinguished by increase IFN-γ/IL-4 ratio. Similar results were observed with the intact probiotics. Our study identified molecular events associated with the oral administration of sub-cellular structures derived from probiotics and their adjuvant capacity to exert immune modulatory function.

Perspectives for the use of latex peptidases from Calotropis procera for control of inflammation derived from Salmonella infections.

BACKGROUND: Anti-inflammatory properties have been attributed to latex proteins of the medicinal plant Calotropis procera. PURPOSE: A mixture of cysteine peptidases (LPp2) from C. procera latex was investigated for control of inflammatory mediators and inflammation in a mouse model of Salmonella infection. METHODS: LPp2 peptidase activity was confirmed by the BANA assay. Cytotoxicity assays were conducted with immortalized macrophages. Peritoneal macrophages (pMØ) from Swiss mice were stimulated with lipopolysaccharide (LPS) in 96-well plates and then cultured with nontoxic concentrations of LPp2. Swiss mice intravenously received LPp2 (10 mg/kg) and then were challenged intraperitoneally with virulent Salmonella enterica Ser. Typhimurium. RESULTS: LPp2 was not toxic at dosages lower than 62.2 µg/mL. LPp2 treatments of pMØ stimulated with LPS impaired mRNA expression of pro-inflammatory cytokines IL-1ß, TNF-α, IL-6 and IL-10. LPp2 increased the intracellular bacterial killing in infected pMØ. Mice given LPp2 had a lower number of leukocytes in the peritoneal cavity in comparison to control groups 6 h after infection. The bacterial burden and histological damage were widespread in target organs of mice receiving LPp2. CONCLUSION: We conclude that LPp2 contains peptidases with strong anti-inflammatory properties, which may render mice more susceptible to early disseminated infection caused by Salmonella.

Comparison of cell invasion, macrophage survival and inflammatory cytokines profiles between Salmonella enterica serovars Enteritidis and Dublin from Brazil.

AIMS: This study compared the capacity of strains of Salmonella enterica serovars Enteritidis and Dublin isolated in Brazil to invade epithelial cells, to be internalized by and survive within macrophages, and to stimulate cytokine release in vitro. METHODS AND RESULTS: Both serovars infected 75 and 73% Caco-2 (human) and MDBK (bovine) epithelial cells respectively. Salmonella Dublin and S. Enteritidis (i) were internalized at the respective rates of 79·6 and 65·0% (P ≤ 0·05) by U937 (human) macrophages, and 70·4 and 66·9% by HD11 (chicken) macrophages; and (ii) multiplied at the respective rates of 3·2- and 2·7-fold within U937 cells, and 1·9- and 1·1-fold (P ≤ 0·05) within HD11 cells respectively. Seventy per cent of 10 S. Dublin strains stimulated IL-8 production, while 70% of S. Enteritidis strains enhanced production of IL-1ß, IL-6, IL-8, IL-10, IL-12p70 and TNF in Caco-2 cells. CONCLUSIONS: Compared with S. Enteritidis, S. Dublin had stronger ability to survive within macrophages and induced weak cytokine production, which may explain the higher incidence of invasive diseases caused by S. Dublin in humans. SIGNIFICANCE AND IMPACT OF THE STUDY: This study compared S. enterica serovars Enteritidis and Dublin to provide comparative data about the profile of the two serovars in cells from humans, the common host and their respective natural animal hosts and vice versa in order to check the differences between these two phylogenetically closely related serovars that share antigenic properties but present different phenotypic behaviours.

Fermentable Fibers Enhance Aspects of Innate and Adaptive Immunity in Piglets infected with Salmonella Typhimurium.

OBJECTIVE: To test the hypothesis that fermentable fiber prevents Salmonella typhimurium infection-associated symptoms by enhancing innate and adaptive immune system in neonatal pigs. METHODS: Two-d-old piglets (n=120) were randomized to receive either a nutritionally complete sow milk replacer formula (CON), or supplemented with methylcellulose (MCEL-non-fermentable), soy polysaccharides (SPS-moderately fermentable), or fructooligosaccharides (FOS-highly fermentable). On d7, piglets received an oral gavage of S. typhimurium-798, and continued receiving the same diets up to 48h post-infection. Ileal mucosal samples were obtained for further analyses. RESULTS: A reduction in chloride secretion was observed in FOS when compared to other diets (p<0.0003). The number of ileal sulfo-acidomucins was higher (p<0.05) in FOS before infection compared with other diets. NFkB was inhibited in FOS following infection (p<0.05), when compared with CON. IL-1ß expression was increased at 4h post-infection (p<0.05) in CON; however, this response was attenuated in the fiber groups. IL-6 expression was higher (p<0.05) in CON post- infection, higher in SPS at 24h (p<0.05), but unchanged in MCEL and FOS when compared to pre-infection values. FOS had a higher expression of neutrophil-chemoattractant IL-8 before infection (p<0.05) compared to other groups. CONCLUSION: The reduction in chloride secretion, proinflammatory cytokines expression and NFkB activation, and increased number of sulfo-acidomucins, and IL-8 expression in the fiber groups, indicates that the degree of fermentability impacts the innate and adaptive immune system, and could be the mechanisms by which dietary fibers reduce S. typhimurium infection-associated-symptoms in neonatal pigs and apply these results to infants.

Latex proteins downregulate inflammation and restores blood-coagulation homeostasis in acute Salmonella infection.

BACKGROUND: Calotropis procera latex protein fraction (LP) was previously shown to protect animals from septic shock. Further investigations showed that LP modulate nitric oxide and cytokines levels. OBJECTIVES: To evaluate whether the protective effects of LP, against lethal bacterial infection, is observed in its subfractions (LPPII and LPPIII). METHODS: Subfractions (5 and 10 mg/kg) were tested by i.p. administration, 24 h before challenging with lethal injection (i.p.) of Salmonella Typhimurium. LPPIII (5 mg/kg) which showed higher survival rate was assayed to evaluate bacterial clearance, histopathology, leukocyte recruitment, plasma coagulation time, cytokines and NO levels. FINDINGS: LPPIII protected 70% of animals of death. The animals given LPPIII exhibited reduced bacterial load in blood and peritoneal fluid after 24 h compared to the control. LPPIII promoted macrophage infiltration in spleen and liver. LPPIII restored the coagulation time of infected animals, increased IL-10 and reduced NO in blood. MAIN CONCLUSIONS: LPPIII recruited macrophages to the target organs of bacterial infection. This addressed inflammatory stimulus seems to reduce bacterial colonisation in spleen and liver, down regulate bacterial spread and contribute to avoid septic shock.

Effect of enzymatic treatment of citrus by-products on bacterial growth, adhesion and cytokine production by Caco-2 cells.

Citrus by-products are inexpensive sources of polyphenols, important bioactive compounds with wide pharmaceutical and food applications. This study aimed to investigate the effect of enzymatic treatment of citrus by-products on the polyphenolic profile of extracts and assess the influence of extracts on the growth and adhesion of probiotics and foodborne pathogenic bacteria and on the inflammatory response of epithelial cells. Enzyme-assisted extraction altered the polyphenolic profile (as assessed by HPLC-DAD), increasing the content of aglycone flavanones (naringenin and hesperetin). Enzymatic extracts and aglycone flavanones exhibited higher antibacterial and prebiotic activities than non-enzymatic extracts and glycoside flavanones. However, a higher content of aglycones was not associated with higher anti-adhesion activity. Citrus extracts significantly (P ≤ 0.05) decreased the inflammatory response of Caco-2 cells to Salmonella Typhimurium adhesion. These results support the sustainable reuse of citrus agroindustrial wastes and indicate the potential of citrus extracts in preventing infection by foodborne pathogenic bacteria and inducing proliferation of probiotics in foods and the gut environment.

Milk Fermented by Lactobacillus paracasei NCC 2461 (ST11) Modulates the Immune Response and Microbiota to Exert its Protective Effects Against Salmonella typhimurium Infection in Mice.

Probiotics form a promising strategy to maintain intestinal health. Milks fermented with probiotic strains, such as the Lactobacillus paracasei ST11, are largely commercialized in Brazil and form a low-cost alternative to probiotic pharmaceutical formulations. In this study, we assessed the probiotic effects of milk fermented by L. paracasei ST11 (administered through fermented milk) in a Salmonella typhimurium infection model in BALB/c mice. We observed in this murine model that the applied probiotic conferred protective effects against S. typhimurium infection, since its administration reduced mortality, weight loss, translocation to target organs (liver and spleen) and ileum injury. Moreover, a reduction in the mRNA expression of pro-inflammatory cytokines such as IFN-γ, IL-6, TNF-α and IL-17 in animals that received the probiotic before challenge was observed. Additionally, the ileum microbiota was better preserved in these animals. The present study highlights a multifactorial protective aspect of this commercial probiotic strain against a common gastrointestinal pathogen.

Latex proteins downregulate inflammation and restores blood-coagulation homeostasis in acute Salmonella infection

BACKGROUND Calotropis procera latex protein fraction (LP) was previously shown to protect animals from septic shock. Further investigations showed that LP modulate nitric oxide and cytokines levels. OBJECTIVES To evaluate whether the protective effects of LP, against lethal bacterial infection, is observed in its subfractions (LPPII and LPPIII). METHODS Subfractions (5 and 10 mg/kg) were tested by i.p. administration, 24 h before challenging with lethal injection (i.p.) of Salmonella Typhimurium. LPPIII (5 mg/kg) which showed higher survival rate was assayed to evaluate bacterial clearance, histopathology, leukocyte recruitment, plasma coagulation time, cytokines and NO levels. FINDINGS LPPIII protected 70% of animals of death. The animals given LPPIII exhibited reduced bacterial load in blood and peritoneal fluid after 24 h compared to the control. LPPIII promoted macrophage infiltration in spleen and liver. LPPIII restored the coagulation time of infected animals, increased IL-10 and reduced NO in blood. MAIN CONCLUSIONS LPPIII recruited macrophages to the target organs of bacterial infection. This addressed inflammatory stimulus seems to reduce bacterial colonisation in spleen and liver, down regulate bacterial spread and contribute to avoid septic shock.

Cancer Immunotherapy: Priming the Host Immune Response with Live Attenuated Salmonella enterica.

In recent years, cancer immunotherapy has undergone great advances because of our understanding of the immune response and the mechanisms through which tumor cells evade it. A century after the first immunotherapy attempt based on bacterial products described by William Coley, the use of live attenuated bacterial vectors has become a promising alternative in the fight against cancer. This review describes the role of live attenuated Salmonella enterica as an oncolytic and immunotherapeutic agent, due to its high affinity for tumor tissue and its ability to activate innate and adaptive antitumor immune response. Furthermore, its potential use as delivery system of tumor antigens and immunomodulatory molecules that induce tumor regression is also reviewed.

Diet-induced obese mice exhibit altered immune responses to early Salmonella Typhimurium oral infection.

Obesity is a chronic disease associated with different metabolic diseases as well as alterations in immune cell function. It is characterized by a chronic systemic low grade inflammation. There are several studies demonstrating the influence of obesity on the impaired immune response to infection. However, it is not completely clear whether the obese environment influences the development or maintenance of the immune response against infections. The aim of this study was to determine how obesity induced by a high-fat diet affects the immune response to an early oral Salmonella infection. Four groups of mice were kept in separate cages. Two of these designated as controls, fed with a normal diet; whereas other two groups were fed with a high fat diet for 10 weeks. Some mice were used for Salmonella oral infection. After 7 days of oral infection with S. Thypimurium the proportions of spleen cell subsets expressing activation markers in normal diet and HFD obese mice were stained with monoclonal antibodies and analyzed by flow cytometry. Also, mRNA levels of different cytokines were quantified by RT-PCR. It was found that obesity affects the function of the immune system against an early oral Salmonella infection, decreasing NK cells, altering the expression of activation molecules as well as cytokines mRNA levels. Interestingly, the expression some activation molecules on T lymphocytes was reestablished after Salmonella infection, but not the CD25 expression. Immune alterations could lead to immunosuppression or increased susceptibility to infections in HFD obese mice.

Integrin αDß2 (CD11d/CD18) Modulates Leukocyte Accumulation, Pathogen Clearance, and Pyroptosis in Experimental Salmonella Typhimurium Infection.

ß2 integrins are critical in host defense responses to invading pathogens and inflammation. Previously, we reported that genetic deficiency of integrin αDß2 in mice altered outcomes in experimental systemic infections including accelerated mortality in animals infected with Salmonella enterica serovar Typhimurium. Here, we show that deficiency of αDß2 results in impaired accumulation of leukocytes in response to peritoneal infection by S. Typhimurium, impaired pathogen clearance in vivo, defective bacterial elimination by cultured peritoneal macrophages, and enhanced pyroptosis, a cell death process triggered by Salmonella. Salmonella-infected animals deficient in αDß2 had increased levels of peritoneal cytokines in addition to other markers of pyroptosis, which may contribute to inflammatory injury and increased mortality in the context of impaired bacterial killing. These observations indicate important contributions of leukocyte integrins to the host response in experimental Salmonella infection and reveal previous activities of αDß2 in bacterial infection.

Persistent Salmonella enterica serovar Typhimurium Infection Increases the Susceptibility of Mice to Develop Intestinal Inflammation.

Chronic intestinal inflammations are triggered by genetic and environmental components. However, it remains unclear how specific changes in the microbiota, host immunity, or pathogen exposure could promote the onset and exacerbation of these diseases. Here, we evaluated whether Salmonella enterica serovar Typhimurium (S. Typhimurium) infection increases the susceptibility to develop intestinal inflammation in mice. Two mouse models were used to evaluate the impact of S. Typhimurium infection: the chemical induction of colitis by dextran sulfate sodium (DSS) and interleukin (IL)-10-/- mice, which develop spontaneous intestinal inflammation. We observed that S. Typhimurium infection makes DSS-treated and IL-10-/- mice more susceptible to develop intestinal inflammation. Importantly, this increased susceptibility is associated to the ability of S. Typhimurium to persist in liver and spleen of infected mice, which depends on the virulence proteins secreted by Salmonella Pathogenicity Island 2-encoded type three secretion system (TTSS-2). Although immunization with a live attenuated vaccine resulted in a moderate reduction of the IL-10-/- mice susceptibility to develop intestinal inflammation due to previous S. Typhimurium infection, it did not prevent bacterial persistence. Our results suggest that persistent S. Typhimurium infection may increase the susceptibility of mice to develop inflammation in the intestine, which could be associated with virulence proteins secreted by TTSS-2.

The cytosolic sensor STING is required for intestinal homeostasis and control of inflammation.

STING (stimulator of interferon genes) is a cytosolic sensor for cyclic dinucleotides and also an adaptor molecule for intracellular DNA receptors. Although STING has important functions in the host defense against pathogens and in autoimmune diseases, its physiological relevance in intestinal homeostasis is largely unknown. In this study, we show that STING-/- mice presented defective protective mechanisms of intestinal mucosa, including decreased number of goblet cells, diminished mucus production, and lower levels of secretory IgA, when compared with wild-type (WT) mice. Fecal content and microbiota DNA could activate STING, indicating a role of this molecule in gut. Microbiota composition was altered in STING-/- mice toward a more inflammatory profile, evidencing a reduction in the Allobacolum and Bifidobacterium groups along with increase in Disulfovibrio bacteria. Absence of STING lead to decrease in induced intraepithelial lymphocytes (IEL) and to increase in group 1 innate lymphoid cell (ILC1) as well as ILC3 frequencies and decrease in ILC2 in the colon. Development and function of Foxp3+ and LAP+ regulatory T cells were also compromised in STING-/- mice. Moreover, these mice were highly susceptible to dextran sodium sulfate-induced colitis, T-cell-induced colitis, and enteric Salmonella typhimurium infection when compared with WT animals. Therefore, our results identify an important role of STING in maintaining gut homeostasis and also a protective effect in controlling gut inflammation.

Immune Response Against Salmonella Enteritidis Is Unsettled by HIV Infection.

The human immunodeficiency virus (HIV) is responsible for more than 2 million new infections per year and opportunistic infections such as Salmonella spp. Gastroenteritis is an important cause of mortality and morbidity in developing countries. Monocytes and macrophages play a critical role in the innate immune response against bacterial infections. However during HIV infection the virus can infect these cells and although they are more resistant to the cytopathic effects, they represent an important viral reservoir in these patients. Our aim was to evaluate the monocyte functions from HIV-1 infected patients after in vitro exposition to Salmonella Enteritidis. Our results suggest impairment of monocytes phagocytic and microbicidal activity in HIV-1 non-treated patients, which was more evident in women, if compared with men. Moreover, monocytes from HIV-1 infected and non-treated patients after stimulation with the bacteria, produced more pro-inflammatory cytokines than monocytes from HIV-treated patients, suggesting that HIV-1 infected patients have their functions unbalanced, once in the presence of an opportunistic infection in vitro.

Relationship between clinical symptomatology on the isolation of Salmonella Gallinarum of japanese quail (Coturnix coturnix) / Relação entre a sintomatologia clínica no isolamento de Salmonella Gallinarum de codornas japonesas (Coturnix coturnix)

Salmonella Gallinarum is capable of causing high mortality in birds of the order Galliformes. This study aimed to relate the presence of clinical signs with the recovery of Salmonella Gallinarum from organs and c loacal swabs of Japanese quails (Coturnix coturnix) experimentally infected. A total of 70 female quails were housed in a pair per cage and divided in two groups (IG: quails inoculated with 1.5x106 CFU of Salmonella Gallinarum Nalr/mL and CG: control group). After the inoculation, birds were evaluated three times a day to verify the presence of clinical signs. Birds that presented ruffled feathers, eyes closed and remained quiet in the cage were removed for euthanasia, as well as the same number of birds from the inoculated groups that presented no clinical signs and from the control group. Cloacal swabbing was performed following euthanasia for the sampling of liver, spleen, caeca, ovarian follicles and lung for microbiological procedure. Quails with clinical signs and quails found dead presented positivity of 100%. While inoculated quails with no clinical signs presented a lower positivity (38.5%). Therefore, quails with septicemia caused by SG present clinical signs of the disease and the pathogen can be isolated and quantified in the organs.(AU)

Salmonella Gallinarum pode causar alta mortalidade em aves da ordem Galliformes. Objetivou-se neste estudo relacionar a presença de sinais clínicos com a recuperação de Salmonella Gallinarum de órgãos e swabs cloacais de codornas japonesas (Coturnix coturnix) experimentalmente infectadas. Um total de 70 codornas fêmeas foram alojadas em par por gaiola e divididas em dois grupos (IG: codornas inoculadas com 1,5x106 UFC de Salmonella Gallinarum Nalr / mL e CG: grupo controle). Após a inoculação, as aves foram avaliadas três vezes ao dia para se verificar a presença de sinais clínicos. As aves que se apresentaram com penas eriçadas, olhos fechados e permaneciam imóveis na gaiola foram removidas para a eutanásia, assim como o mesmo número de aves dos grupos inoculados que não apresentaram sinais clínicos e do grupo controle. O swab cloacal foi realizado após a eutanásia para a amostragem de fígado, baço, ceco, folículos ovarianos e pulmão para procedimento microbiológico. As codornas com sinais clínicos e as encontradas mortas apresentaram positividade de 100%, enquanto as codornas inoculadas sem sinais clínicos apresentaram menor positividade (38,5%). Portanto, codornas com septicemia causada por SG apresentam sinais clínicos da doença e o patógeno pode ser isolado e quantificado em diversos órgãos.(AU)

Relationship between clinical symptomatology on the isolation of Salmonella Gallinarum of japanese quail (Coturnix coturnix) / Relação entre a sintomatologia clínica no isolamento de Salmonella Gallinarum de codornas japonesas (Coturnix coturnix)

Salmonella Gallinarum is capable of causing high mortality in birds of the order Galliformes. This study aimed to relate the presence of clinical signs with the recovery of Salmonella Gallinarum from organs and c loacal swabs of Japanese quails (Coturnix coturnix) experimentally infected. A total of 70 female quails were housed in a pair per cage and divided in two groups (IG: quails inoculated with 1.5x106 CFU of Salmonella Gallinarum Nalr/mL and CG: control group). After the inoculation, birds were evaluated three times a day to verify the presence of clinical signs. Birds that presented ruffled feathers, eyes closed and remained quiet in the cage were removed for euthanasia, as well as the same number of birds from the inoculated groups that presented no clinical signs and from the control group. Cloacal swabbing was performed following euthanasia for the sampling of liver, spleen, caeca, ovarian follicles and lung for microbiological procedure. Quails with clinical signs and quails found dead presented positivity of 100%. While inoculated quails with no clinical signs presented a lower positivity (38.5%). Therefore, quails with septicemia caused by SG present clinical signs of the disease and the pathogen can be isolated and quantified in the organs.(AU)

Salmonella Gallinarum pode causar alta mortalidade em aves da ordem Galliformes. Objetivou-se neste estudo relacionar a presença de sinais clínicos com a recuperação de Salmonella Gallinarum de órgãos e swabs cloacais de codornas japonesas (Coturnix coturnix) experimentalmente infectadas. Um total de 70 codornas fêmeas foram alojadas em par por gaiola e divididas em dois grupos (IG: codornas inoculadas com 1,5x106 UFC de Salmonella Gallinarum Nalr / mL e CG: grupo controle). Após a inoculação, as aves foram avaliadas três vezes ao dia para se verificar a presença de sinais clínicos. As aves que se apresentaram com penas eriçadas, olhos fechados e permaneciam imóveis na gaiola foram removidas para a eutanásia, assim como o mesmo número de aves dos grupos inoculados que não apresentaram sinais clínicos e do grupo controle. O swab cloacal foi realizado após a eutanásia para a amostragem de fígado, baço, ceco, folículos ovarianos e pulmão para procedimento microbiológico. As codornas com sinais clínicos e as encontradas mortas apresentaram positividade de 100%, enquanto as codornas inoculadas sem sinais clínicos apresentaram menor positividade (38,5%). Portanto, codornas com septicemia causada por SG apresentam sinais clínicos da doença e o patógeno pode ser isolado e quantificado em diversos órgãos.(AU)

Influence of Technological Treatments on the Functionality of Bifidobacterium lactis INL1, a Breast Milk-Derived Probiotic.

The aim of this study is to evaluate the influence of the technological processing on the functionality of the human breast milk probiotic strain Bifidobacterium lactis INL1. In vitro antagonistic activity of B. lactis INL1 was detected for Gram-positive and Gram-negative pathogens. B. lactis INL1 was administered to mice as fresh (F), frozen (Z), spray-dried (S), or lyophilized (L) culture. Immune parameters (IgA, IL-10, and IFN-γ) were determined and histological analysis was performed to assess functionality and protection capacity against Salmonella. In BALB/c mice, F and S cultures induced an increase in the number of IgA-producing cells in the small intestine and IL-10 levels were increased for L culture in the large intestine. In Swiss mice, B. lactis INL1 increased secretory-IgA levels in the small intestine before and after Salmonella infection, both as F or dehydrated culture. Also, an attenuation of damage in the intestinal epithelium and less inflammatory infiltrates were observed in animals that received F and S cultures, whereas in liver only F showed some effect. The anti-inflammatory effect was confirmed in both tissues by myeloperoxidase activity and by IFN-γ levels in the intestinal content. B. lactis INL1 showed inhibitory activity against pathogens and confirmed its probiotic potential in animal models. Technological processing of the probiotic strain affected its functionality. PRACTICAL APPLICATION: This work provides evidence about the influence of technology on the functionality of probiotics, which may help probiotics and functional food manufacturers to take processing into consideration when assessing the functionality of new strains.

Milk fermented by Lactobacillus species from Brazilian artisanal cheese protect germ-free-mice against Salmonella Typhimurium infection.

Ingestion of milks fermented by Lactobacillus strains showing probiotic properties is an important tool to maintain gastrointestinal health. In this study, Lactobacillus rhamnosus D1 and Lactobacillus plantarum B7, isolated from Brazilian artisanal cheese, were used as starters for the functional fermented milks to assess their probiotic properties in a gnotobiotic animal model. Male germ-free Swiss mice received a single oral dose of milk fermented by each sample, and were challenged with Salmonella Typhimurium five days afterwards. Milk fermented by both Lactobacillus strains maintained counts above 108 cfu/ml during cold storage. Lactobacillus strains colonised the gut of the germ-free-mice, maintaining their antagonistic effect. This colonisation led to a protective effect against Salmonella challenge, as demonstrated by reduced pathogen translocation and histological lesions, when compared to control group, especially for Lactobacillus rhamnosus D1. Additionally, mRNA expression of inflammatory (interferon gamma, interleukin (IL)-6, tumour necrosis factor alpha) and anti-inflammatory (transforming growth factor ß1) cytokines was augmented in animals previously colonised and then challenged, when compared to other experimental groups. Lactobacillus plantarum B7 colonisation also promoted higher expression of IL-17, showing a proper maturation of colonised germ-free-mice immune system. IL-5 was stimulated by both strains' colonisation and not by S. Typhimurium challenge.

Costs of biosecurity measures in Brazilian laying hens farms in response to policies against Avian Influenza, Newcastle Disease and Salmonellosis / Custos das medidas de biosseguridade na produção brasileira de galinhas poedeiras em resposta às políticas sanitárias contra a gripe aviária, doença de Newcastle e Salmonelose

The objective of this study was to estimate costs for egg production and for implementation of biosecurity measures described by Normative Instructions No. 56/2007, No. 59/2009, No. 36/2012 and No. 10/2013 on production costs in these establishments. To attend the “National Avian Health Program” and the “National Plan for the Prevention of Avian Influenza and Control and Prevention of Newcastle Disease”, the Brazilian Ministry of Agriculture published a series of legal acts to establish the “Procedures for Register, Inspection and Control of Breeding and Commercial Avian Establishments” intensifying the measures for prevention of high economic impact illnesses in avian flocks of the country. The adaptations comprise items of structure and biosecurity procedures that aim to increase the level of isolation of the birds to maintain them with the best health status as possible. These adaptations can result in more expenses and dedication from the producers. Thus, production costs were obtained through personal interviews with 10 voluntary commercial farmers of laying hens in Limeira region, Sao Paulo State, Brazil, between June and July, 2013. The result of this study suggests that the implementation of biosecurity measures has relatively low costs when compared to the possible risks of diseases outbreaks and the consequent economic losses that justify the adoption of these practices.(AU)

O objetivo com este trabalho foi estimar os custos para produção de ovos, bem como os impactos da implementação das normas de biosseguridade descritas pelas normativas de número 56/2007, 59/2009, 36/2012, 10/2013. Visando o atendimento ao “Programa Nacional de Sanidade Avícola” e ao “Plano Nacional de Prevenção da Influenza Aviária e de Controle e Prevenção da Doença de Newcastle”, o Ministério da Agricultura publicou uma série de atos legais para estabelecer os “Procedimentos para Registro, Fiscalização e Controle de Estabelecimentos Avícolas de Reprodução e Comerciais”, intensificando as medidas para prevenção da ocorrência de enfermidades de grande impacto econômico no plantel avícola do país. As adequações englobam itens de estrutura e procedimentos de biosseguridade que visam aumentar o nível de isolamento das aves, para mantê-las com o melhor status sanitário possível. Essas exigências podem resultar em mais despesas e dedicação por parte dos produtores. Desta forma, custos de produção foram obtidos por meio de entrevistas pessoais com 10 produtores de fazendas comerciais de avicultura de postura na região de Limeira, Estado de São Paulo, Brasil, entre junho e julho de 2013. O resultado deste estudo sugere que a implantação da biosseguridade tem custo relativamente baixo frente aos possíveis riscos de enfermidades e dos prejuízos econômicos que essas enfermidades podem causar, o que justifica a adoção destas práticas.(AU)