In vitro effects of alginate lyase SG4 + produced by Paenibacillus lautus alone and combined with antibiotics on biofilm formation by mucoid Pseudomonas aeruginosa.

Alginate is a major extra polymeric substance in the biofilm formed by mucoid Pseudomonas aeruginosa. It is the main proven perpetrator of lung infections in patients suffering from cystic fibrosis. Alginate lyases are very important in the treatment of cystic fibrosis. This study evaluated the role of standalone and in conjugation, effect of alginate lyase of SG4 + isolated from Paenibacillus lautus in enhancing in vitro bactericidal activity of gentamicin and amikacin on mucoid P. aeruginosa. Using Response Surface Methodology (RSM) alginate lyase SG4 + production was optimized in shake flask and there 8.49-fold enhancement in enzyme production. In fermenter, maximum growth (10.15 mg/ml) and alginate lyase (1.46 International Units) production, 1.71-fold was increased using Central Composite Design (CCD). Further, fermentation time was reduced from 48 to 20 h. To the best of our knowledge this is the first report in which CCD was used for fermenter studies to optimize alginate lyase production. The Km and Vmax of purified enzyme were found to be 2.7 mg/ml and 0.84 mol/ml-min, respectively. The half-life (t 1/2) of purified alginate lyase SG4 + at 37 °C was 180 min. Alginate lyase SG4 + in combination with gentamicin and amikacin eradiated 48.4- 52.3% and 58- 64.6%, alginate biofilm formed by P. aeruginosa strains, respectively. The study proves that alginate lyase SG4 + has excellent exopolysaccharide disintegrating ability and may be useful in development of potent therapeutic agent to treat P. aeruginosa biofilms.

Lignin Analysis by HPLC and FTIR: Spectra Deconvolution and S/G Ratio Determination.

Fourier transform infrared spectroscopy (FTIR) is a simple nondestructive technique that allows the user to obtain quick and accurate information about the structure of the constituents of wood. Spectra deconvolution is a computational technique, complementary to FTIR analysis, which improves the resolution of overlapped or unobserved bands in the raw spectra. High performance liquid chromatography (HPLC) is an analytical technique useful to determine the ratio of the lignin monomers obtained by the alkaline nitrobenzene oxidation method. Furthermore, lignin content has been commonly determined by wet chemical methods; Klason lignin determination is a quick and accessible method. Here, we detail the procedures for chemical analysis of the wood lignin using these techniques. Additionally, the deconvolution process of FTIR spectra for the determination of the S/G ratio, in lignin isolated by this or other methods, is explained in detail.

La prueba de figuras enmascaradas en la versión SaWa sobre figuras Gottschaldt ­presentación e indicadores psicométricos / The Embedded Figures Test in the SaWa Version on Gottschaldt Figures ­Presentation and Psychometric Indicators­ / O teste de figuras mascaradas na versão SaWa em figuras de Gottschaldt ­Apresentação e indicadores psicométricos­

El artículo presenta la versión de la prueba EfT desarrollada por Sawa sobre las figuras Gottschaldt, como indicador de la capacidad de reestructuración perceptual y del estilo cognitivo en la dimensión de independencia- dependencia de campo. Se examina la consistencia interna del instrumento, su validez estructural y de constructo a partir de los datos recogidos en cuatro diferentes estudios en los que ha sido aplicado (n = 6.530). Los resultados indican altos niveles de consistencia interna y adecuados niveles de validez estructural del instrumento. La validez de constructo se determina mediante el examen de los comportamientos de la prueba frente al sexo y el grado/edad. Los resultados demuestran que el instrumento se comporta de acuerdo con lo esperado en el constructo. Por último, se presentan los baremos del instrumento

This paper presents the version of the Embedded Figures Test (EfT) that Sawa developed using Gottschaldt's figures. The test indicates the perceptual restructur- ing ability and the field dependence-independence dimension of cognitive style. The instrument's internal consistency and its structural and construct validity are examined using data collected in four previous studies in which the test was administered (n = 6.530). Results show high levels of internal consistency and adequate levels of structural validity. The construct validity was determined by examining the instrument's behavior regarding sex and grade/age. Results indicate that the test behaves as expected considering the construct. Finally, the instrument's norms are presented

O artigo apresenta a versão do teste EfT, desenvol- vida por Sawa sobre as figuras de Gottchaldt, como indicador da capacidade de reestruturação perceptiva e, do estilo cognitivo na dimensão independência- -dependência do campo. A consistência interna do instrumento, sua validade estrutural e sua validade de construto são examinadas a partir dos dados co- letados em quatro diferentes estudos em que o teste foi aplicado (n = 6.530). Os resultados indicam altos níveis de consistência interna e níveis adequados de validade estrutural do instrumento. A validade de cons- truto é determinada examinando os comportamentos de teste em relação ao gênero e nível de escolaridade/ idade. Os resultados indicam que o instrumento se comporta conforme o esperado no construto. Por fim, são apresentadas as escalas do instrumento.

Cellular immune response after vaccination with Salmonella Gallinarum 9R in laying hens and addition of aflatoxin and absorbent in the feed.

Salmonella Gallinarum greatly impacts commercial flocks and vaccination with S. Gallinarum 9R (SG9R) is one of the most effective control strategies in some countries. However, mycotoxins can affect immunization success. Herein, we measured the cellular immune response in SG9R-vaccinated hens, quantified the impact of aflatoxins on the immune response, and determined whether the anti-mycotoxin additive (adsorbent) influences immunity after vaccination. One-day-old chicks of commercial laying hens were raised until 49 days of age and were assigned to six groups. T1 (control group): control diet (no detectable concentration of aflatoxin), no vaccine or adsorbent. T2: vaccine SG-9R at day 28, aflatoxins 2.5 ppm from day 1 to day 49, and adsorbent 2.5 Kg/ton. T3: control diet and vaccine. T4: aflatoxins and vaccine. T5: control diet and aflatoxins. T6: aflatoxins and adsorbent. Body weights were evaluated on days 1, 31, and 41. Cellular immune response was evaluated by flow cytometry at 31, 41, and 49 days of age. T lymphocytes, B lymphocytes, monocytes, phagocytic monocytes and heterophils were evaluated. Aflatoxins suppressed peripheral and mucosal helper T lymphocytes, and mucosal cytotoxic T lymphocytes in vaccinated birds (T2 and T4). However, inclusion of the adsorbent in the feed of vaccinated birds neutralized the effects of aflatoxin (T6). The concentration of immune cells may show differences after SG9R vaccination, particularly an increase in the monocyte concentration. The SG9R vaccine reduced the concentration of activated cytotoxic T lymphocytes, making this marker a good parameter to analyze before and three weeks after immunization.

Neuropsychiatric and sleep study in autosomal dominant dopa-responsive dystonia.

Introduction: Although the diurnal fluctuation of motor dysfunction, reversible with small doses of dopamine, is a cornerstone for the phenotype of the autosomal dominant Segawa syndrome, the non-motor symptoms of this neurotransmitter deficiency have still received limited attention. Objective: This study aims to evaluate non-motor symptoms of this dopa-responsive dystonia through an intrafamilial comparative cross-sectional study. Methods: Seventeen individuals with a c.IVS5 + 3insT (c.626 + 3insT) variation in the GTP cyclohydrolase-1 gene (GCH1, HGNC: 4193) and 34 intrafamilial controls were studied using the Beck Depression Inventory-II, the Wiener Matrizen Test 2, the Epworth Sleepiness Scale, the Pittsburgh Sleep Quality Index, the MINI/MINI PLUS Questionnaires, the World Health Organization Quality of Life - BREF Instrument and a drug use assessment questionnaire. Results: No significant difference was found between the groups in the prevalence of sleep disorders and in cognitive function. Nevertheless, generalized anxiety disorder (p = 0.050) and attention-deficit/hyperactivity disorder in childhood (p = 0.011) were observed only in individuals without the molecular variation. The group with the GCH1 variation presented a worse perception about how safe they feel in their daily lives (p = 0.034), less satisfaction with themselves (p = 0.049) and with their relationships (p = 0.029), and a higher prevalence of past major depressive episodes before use of L-Dopa (p = 0.046). Conclusion: Low dopamine could have been protective against generalized anxiety disorder and attention-deficit/hyperactivity disorder in childhood in Segawa group individuals. The prevalence of depression was higher in individuals with the molecular variant prior to the L-Dopa treatment. Considering it, the penetrance estimates for the variant carriers increased from 58.8% to up to 88% in this large studied family. Additionally, neuropsychiatric tests of all individuals with a molecular diagnosis in an affected family are a valuable instrument for its clinical management.

Hevea brasiliensis coniferaldehyde-5-hydroxylase (HbCAld5H) regulates xylogenesis, structure and lignin chemistry of xylem cell wall in Nicotiana tabacum.

KEY MESSAGE: The HbCAld5H1 gene cloned from Hevea brasiliensis regulates the cambial activity, xylem differentiation, syringyl-guaiacyl ratio, secondary wall structure, lignification pattern and xylan distribution in xylem fibres of transgenic tobacco plants. Molecular characterization of lignin biosynthesis gene coniferaldehyde-5-hydroxylase (CAld5H) from Hevea brasiliensis and its functional validation was performed. Both sense and antisense constructs of HbCAld5H1 gene were introduced into tobacco through Agrobacterium-mediated genetic transformation for over expression and down-regulation of this key enzyme to understand its role affecting structural and cell wall chemistry. The anatomical studies of transgenic tobacco plants revealed the increase of cambial activity leading to xylogenesis in sense lines and considerable reduction in antisense lines. The ultra-structural studies showed that the thickness of secondary wall (S2 layer) of fibre had been decreased with non-homogenous lignin distribution in antisense lines, while sense lines showed an increase in S2 layer thickness. Maule color reaction revealed that syringyl lignin distribution in the xylem elements was increased in sense and decreased in antisense lines. The immunoelectron microscopy revealed a reduction in LM 10 and LM 11 labelling in the secondary wall of antisense tobacco lines. Biochemical studies showed a radical increase in syringyl lignin in sense lines without any significant change in total lignin content, while S/G ratio decreased considerably in antisense lines. Our results suggest that CAld5H gene plays an important role in xylogenesis stages such as cambial cell division, secondary wall thickness, xylan and syringyl lignin distribution in tobacco. Therefore, CAld5H gene could be considered as a promising target for lignin modification essential for timber quality improvement in rubber.

FT-NIR spectroscopy and RP-HPLC combined with multivariate analysis reveals differences in plant cell suspension cultures of Thevetia peruviana treated with salicylic acid and methyl jasmonate.

Plant cell suspension culture of T. peruviana is a feasible biotechnological platform for the production of secondary metabolites with anti-proliferative/cytotoxic activity, as phenolic compounds (PC); however, different in in vitro growth conditions may affect the production, demanding strategies to increase the metabolite biosynthesis, as well as the development of sensitive and rapid analytical methods for metabolite monitoring. The Fourier transform near-infrared (FT-NIR) spectroscopy and Reversed-phase high-performance liquid chromatography (RP-HPLC) combined with Multivariate analysis (MVA) were used to detect significant differences in the PC production in cultures treated with two elicitors. The results suggest that the FT-NIR-MVA is useful for discriminating samples according to the treatment, showed significant influence of the PC signal. RP-HPLC-MVA showed that the elicitor effect occurs at 72 h post-elicitation. Detection of dihydroquercetin (maximum concentration = 12.59 mg/L), a flavonoid with anti-cancer properties, is highlighted. Future studies will be aimed at scaling this culture to increase the productivity of dihydroquercetin.

Hemato-biochemical profile of meat cattle submitted to different types of pre-loading handling and transport times.

Pre-loading handling and conditions of transport are related to welfare, disease risk and product quality of production animals. These steps continue to be one of the major animal management problems in Brazil. This study evaluated the effects of different types of pre-loading handling and road transport times on the haematological and biochemical traits of cattle. Eighteen male cattle were submitted to three travel times (24, 48 and 72 h) in a truck soon after load using different types of pre-loading handling: traditional (rough handling), training (gentle handling) and use of flags to movement cattle. Haematological traits, blood biochemical measures as well as blood and faecal cortisol were analysed in order to assess animal welfare and physiological status. The traditional management showed to be more stressful, also had animals with a greater number of neutrophils and lower numbers of lymphocytes than handling with flags, showing that animals submitted to more stressful situations can have compromised immune system. Serum aspartate aminotransferase concentrations were within the reference levels and when taken together with increased creatine kinase patterns observed indicate muscle damage in traditional management. Decrease in glucose concentrations over time from traditional management to flag management was observed, while fructosamine was increased in traditional management with 72 h of travel. When taken together, all reported factors, immune, enzymatic, energetic and hormonal, indicate that the quality of pre-loading handling and time of transport were determinant for animal welfare, its homeostatic balance and sanitary conditions.

Lignin-induced growth inhibition in soybean exposed to iron oxide nanoparticles.

Plants are occasionally exposed to environmental perturbations that limit their growth. One of these perturbations is the exposure to and interaction with various nanoparticles (NPs) that are discarded continuously into the environment. Hitherto, no study has been carried out evaluating the effects of iron oxide (γ-Fe2O3) NPs on soybean growth and lignin formation, as proposed herein. For comparative purposes, we also submitted soybean plants to non-nanoparticulate iron (FeCl3). Exposure of the plants to γ-Fe2O3 NPs increased cell wall-bound peroxidase (POD) activity but decreased phenylalanine ammonia lyase (PAL) activity due, probably, to the negative feedback of accumulated phenolic compounds. In contrast, FeCl3 decreased cell wall-bound POD activity. Both γ-Fe2O3 NPs and FeCl3 increased the lignin content of roots and stems. However, significant lignin-induced growth inhibition was noted only in stems after exposure to NPs, possibly due to changes in lignin monomer composition. In this case, γ-Fe2O3 NPs decreased the guaiacyl monomer content of roots but increased that of stems. The high levels of monomer guaiacyl in stems resulting from the action of γ-Fe2O3 NPs decreased syringyl/guaiacyl ratios, generating more highly cross-linked lignin followed by the stiffening of the cell wall and growth inhibition. In contrast, FeCl3 increased the contents of monomers p-hydroxyphenyl and syringyl in roots. The observed increase in the syringyl/guaiacyl ratio in plant roots submitted to FeCl3 agrees with the lack of effect on growth, due to the formation of a less condensed lignin. In brief, we here describe that γ-Fe2O3 NPs and FeCl3 act differently in soybean plants.

Decaffeinated coffee improves insulin sensitivity in healthy men.

Epidemiological studies have found coffee consumption is associated with a lower risk for type 2 diabetes mellitus, but the underlying mechanisms remain unclear. Thus, the aim of this randomised, cross-over single-blind study was to investigate the effects of regular coffee, regular coffee with sugar and decaffeinated coffee consumption on glucose metabolism and incretin hormones. Seventeen healthy men participated in five trials each, during which they consumed coffee (decaffeinated, regular (containing caffeine) or regular with sugar) or water (with or without sugar). After 1 h of each intervention, they received an oral glucose tolerance test with one intravenous dose of [1-13C]glucose. The Oral Dose Intravenous Label Experiment was applied and glucose and insulin levels were interpreted using a stable isotope two-compartment minimal model. A mixed-model procedure (PROC MIXED), with subject as random effect and time as repeated measure, was used to compare the effects of the beverages on glucose metabolism and incretin parameters (glucose-dependent insulinotropic peptide (GIP)) and glucagon-like peptide-1 (GLP-1)). Insulin sensitivity was higher with decaffeinated coffee than with water (P<0·05). Regular coffee with sugar did not significantly affect glucose, insulin, C-peptide and incretin hormones, compared with water with sugar. Glucose, insulin, C-peptide, GLP-1 and GIP levels were not statistically different after regular and decaffeinated coffee compared with water. Our findings demonstrated that the consumption of decaffeinated coffee improves insulin sensitivity without changing incretin hormones levels. There was no short-term adverse effect on glucose homoeostasis, after an oral glucose challenge, attributable to the consumption of regular coffee with sugar.

Sarcoma de mediastino. Serie de casos y revisión de la literatura. Departamento de Oncología Torácica. Instituto Nacional de Cancerología. INCan / Mediastinal sarcoma. Literature review and a series of cases. Department of Thoracic Oncology. National Institute of Cancerology. INCan

Resumen El sarcoma de mediastino es un raro tumor que representa menos del 10% de los tumores del mediastino y alrededor del 1-2% de todas las neoplasias malignas en general. Debe abordarse en centros de referencia, donde se evalué multidisciplinariamente y se tengan opciones de manejo multimodal, infraestructura que permita la resección y reconstrucción quirúrgica mayor y estricto seguimiento, teniendo en cuenta la alta recurrencia local, cercana al 30%. Exponemos una serie de casos presentados a lo largo de 20 años de experiencia con la participación de varios departamentos, ajustándonos a la definición y manejo con la literatura actual.

Abstract Mediastinum sarcoma is a rare tumor that represents less than 10% of mediastinal tumors and about 1-2% of all malignancies in general. It should be approached in reference centers with multidisciplinary evaluation and multimodal management options, with an infrastructure that allows surgical resection and reconstruction and strict follow-up, taking into account the high local recurrence that is close to 30%. Therefore, we present a series of cases in 20 years of experience with the participation of several departments and adjusting the definition and management with the current literature.

α-Tocopherol in breast milk of women with preterm delivery after a single postpartum oral dose of vitamin E.

We evaluated the effect of maternal vitamin E supplementation on the α-tocopherol concentrations of colostrum, transitional milk and mature milk of women who had given birth prematurely. This longitudinal randomised-controlled trial divided eighty-nine women into two groups: a control group and a supplemented group. Blood and breast milk were collected from all the participants after delivery. Next, each woman in the supplemented group received 400 IU of RRR-α-tocopheryl acetate. Further breast milk samples were collected 24 h after the first collection, as well as 7 and 30 d after delivery. α-Tocopherol concentrations were determined by HPLC. The baseline α-tocopherol concentrations in the maternal serum of the two groups were similar: 1159·8 (sd 292·4) µg/dl (27·0 (SD 6·8) µmol/l) for the control group and 1128·3 (sd 407·2) µg/dl (26·2 (SD 9·5) µmol/l) for the supplemented group. None of the women was vitamin E deficient. Breast milk α-tocopherol concentrations increased by 60 % 24 h after supplementation in the intervention group and did not increase at all in the control group. α-Tocopherol concentration of the transitional milk in the supplemented group was 35 % higher compared with the control group. α-Tocopherol concentrations of the mature milk in both groups were similar. Maternal supplementation with 400 IU of RRR-α-tocopherol increased the vitamin E concentrations of the colostrum and transitional milk, but not of the mature milk. This study presents relevant information for the design of strategies to prevent and combat vitamin E deficiency in the risk group of preterm infants.

Predictors of urinary bisphenol A and phthalate metabolite concentrations in Mexican children.

Exposure to endocrine disrupting chemicals such as bisphenol A (BPA) and phthalates is prevalent among children and adolescents, but little is known regarding important sources of exposure at these sensitive life stages. In this study, we measured urinary concentrations of BPA and nine phthalate metabolites in 108 Mexican children aged 8-13 years. Associations of age, time of day, and questionnaire items on external environment, water use, and food container use with specific gravity-corrected urinary concentrations were assessed, as were questionnaire items concerning the use of 17 personal care products in the past 48-h. As a secondary aim, third trimester urinary concentrations were measured in 99 mothers of these children, and the relationship between specific gravity-corrected urinary concentrations at these two time points was explored. After adjusting for potential confounding by other personal care product use in the past 48-h, there were statistically significant (p<0.05) positive associations in boys for cologne/perfume use and monoethyl phthalate (MEP), mono(3-carboxypropyl) phthalate (MCPP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and in girls for colored cosmetics use and mono-n-butyl phthalate (MBP), mono(2-ethylhexyl) phthalate (MEHP), MEHHP, MEOHP, and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), conditioner use and MEP, deodorant use and MEP, and other hair products use and MBP. There was a statistically significant positive trend for the number of personal care products used in the past 48-h and log-MEP in girls. However, there were no statistically significant associations between the analytes and the other questionnaire items and there were no strong correlations between the analytes measured during the third trimester and at 8-13 years of age. We demonstrated that personal care product use is associated with exposure to multiple phthalates in children. Due to rapid development, children may be susceptible to impacts from exposure to endocrine disrupting chemicals; thus, reduced or delayed use of certain personal care products among children may be warranted.

Prenatal urinary phthalate metabolites levels and neurodevelopment in children at two and three years of age.

BACKGROUND: Previous studies suggest that prenatal phthalate exposure affects neurodevelopment and behavior during the first years of life. OBJECTIVES: To evaluate the effect of maternal urinary concentrations of phthalate metabolites during pregnancy on mental and psychomotor development in children 24-36 months of age. METHODS: This analysis was conducted on the first three years of life among a subsample of 136 mother-child pairs from the ELEMENT cohort studies conducted in Mexico City. Maternal urine samples collected during the third trimester of pregnancy were analyzed for 9 phthalate metabolites: Mono-ethyl phthalate (MEP), Mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), mono-benzyl phthalate (MBzP), Mono-3-carboxypropyl phthalate (MCPP), and four di-2-ethylhexyl phthalate (DEHP) metabolites [mono-2-ethylhexyl-phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP)]. Among the 136 children, 135 (99.3%) completed the study period. Child neurodevelopment was assessed using mental and psychomotor development indexes (MDI and PDI) from a Bayley (BSID II) test at 24, 30, and 36 months of age. The effect of prenatal phthalate exposure on neurodevelopment was estimated using linear regression models for longitudinal data clustered at the individual level. RESULTS: No significant associations were observed among all children combined, but differential effects by gender were found. Among girls, there was a negative association between MDI and DEHP metabolites MEHP (ß=-2.11 [95% CI: -3.73, -0.49]), MEHHP (ß=-1.89 [95% CI: -3.64, -0.15]), MEOHP (ß=-1.80 [95% CI: -3.58, -0.03]) MECPP (ß=-2.52 [95% CI: -4.44, -0.61]), and ΣDEHP (ß=-3.41 [95% CI: -5.26, -1.55]); there was no significant effect among boys. Male PDI was positively related to MBzP (ß=1.79 [95% CI: 0.14, 3.45]) and MCPP (ß=1.64 [95% CI: 0.15, 3.12]); there was no significant effect on PDI among girls. CONCLUSION: This study demonstrates that sex plays a role of an effect modifier in the association between prenatal phthalate exposure and neurodevelopment.

Reversion to virulence evaluation of a 9R vaccine strain of Salmonella enterica serovar gallinarum in commercial brown layers

The live vaccine Cevac S. Gallinarum, made from a rough strain of Salmonella enterica subspecies enterica serotype Gallinarum is used for preventing fowl typhoid, a disease that still causes considerable economic losses in countries with a developing poultry industry. The objective of this paper was to evaluate a possible reversion to virulence of the strain used in a vaccine in commercial brown layers. Only Salmonella-free chicks were utilized. One hundred twenty (120) 12-day-old Dekalb brown layers divided in two trials were used. The first trial had six groups of 15 birds each. Birds of group 1 were vaccinated with 10 doses of Cevac S. Gallinarum subcutaneously and 10 doses orally, in a total of 20 doses of vaccine. Then the birds of groups 2, 3, 4, and 5 received inocula that contained feces and a pool of organs with fragments of liver, heart, spleen, and cecal tonsils obtained from the immediately previous group. The second trial had three groups with 10 birds each. Birds in group 7 received inocula containing a pool of organs from birds of group 5 from trial 1, whilst the birds in group 8 were vaccinated subcutaneously with one dose of vaccine. Both trials included negative control groups (6 and 9). Throughout the experimental period, birds were monitored for reactions to the vaccination on the site of administration, clinical signs, and post-mortem lesions. In each passage, in addition to the birds euthanized to provide the inocula material, two birds from each group were euthanized for assessment of possible lesions, and their organs (liver, heart, spleen and cecal tonsils) were cultured in an attempt to isolate the vaccine strain. Except for one bird from group 1, that had a local reaction on the site of vaccination - a small vesicle with less that 0.5 mm that persisted until the third day post vaccination -, no other bird had any local reaction to the vaccine or any visible clinical alteration. Birds in group 8 did not present any reaction or clinical alteration because of the vaccine. We only managed to re-isolate the vaccine strain in the inocula made from organs of birds in group 1. We confirmed the isolation by means of biochemical tests, serology, and acriflavine agglutination test. All other cultures made from organs or feces, from all the other experimental groups did not show any growth of the vaccine strain or any other Salmonella serovar, suggesting that the vaccinated birds did not shed the SG9R vaccine strain. No bird presented any clinical symptoms or died during the trials, and no gross lesions were observed in the post-mortem examinations. Under the controlled conditions and time-frame of the present experiment, it was possible to conclude that the rough 9R strain of Salmonella Gallinarum present in the vaccine Cevac S. Gallinarum (Ceva Campinas Ltda. - Campinas, SP - Brazil) did not revert to virulence.

Reversion to virulence evaluation of a 9R vaccine strain of Salmonella enterica serovar gallinarum in commercial brown layers

The live vaccine Cevac S. Gallinarum, made from a rough strain of Salmonella enterica subspecies enterica serotype Gallinarum is used for preventing fowl typhoid, a disease that still causes considerable economic losses in countries with a developing poultry industry. The objective of this paper was to evaluate a possible reversion to virulence of the strain used in a vaccine in commercial brown layers. Only Salmonella-free chicks were utilized. One hundred twenty (120) 12-day-old Dekalb brown layers divided in two trials were used. The first trial had six groups of 15 birds each. Birds of group 1 were vaccinated with 10 doses of Cevac S. Gallinarum subcutaneously and 10 doses orally, in a total of 20 doses of vaccine. Then the birds of groups 2, 3, 4, and 5 received inocula that contained feces and a pool of organs with fragments of liver, heart, spleen, and cecal tonsils obtained from the immediately previous group. The second trial had three groups with 10 birds each. Birds in group 7 received inocula containing a pool of organs from birds of group 5 from trial 1, whilst the birds in group 8 were vaccinated subcutaneously with one dose of vaccine. Both trials included negative control groups (6 and 9). Throughout the experimental period, birds were monitored for reactions to the vaccination on the site of administration, clinical signs, and post-mortem lesions. In each passage, in addition to the birds euthanized to provide the inocula material, two birds from each group were euthanized for assessment of possible lesions, and their organs (liver, heart, spleen and cecal tonsils) were cultured in an attempt to isolate the vaccine strain. Except for one bird from group 1, that had a local reaction on the site of vaccination - a small vesicle with less that 0.5 mm that persisted until the third day post vaccination -, no other bird had any local reaction to the vaccine or any visible clinical alteration. Birds in group 8 did not present any reaction or clinical alteration because of the vaccine. We only managed to re-isolate the vaccine strain in the inocula made from organs of birds in group 1. We confirmed the isolation by means of biochemical tests, serology, and acriflavine agglutination test. All other cultures made from organs or feces, from all the other experimental groups did not show any growth of the vaccine strain or any other Salmonella serovar, suggesting that the vaccinated birds did not shed the SG9R vaccine strain. No bird presented any clinical symptoms or died during the trials, and no gross lesions were observed in the post-mortem examinations. Under the controlled conditions and time-frame of the present experiment, it was possible to conclude that the rough 9R strain of Salmonella Gallinarum present in the vaccine Cevac S. Gallinarum (Ceva Campinas Ltda. - Campinas, SP - Brazil) did not revert to virulence.