Abstract DNA vaccines have been evaluated as an option to prevent several diseases. In this study, the capacity of the xanthan biopolymer to improve the DNA vaccines immune response, administered intramuscularly, was evaluated. The experimental vaccines consisted of genes encoding fragments of the proteins LigA and LigB of Leptospira interrogans serogroup Icterohaemorrhagiae serovar Copenhageni strain Fiocruz L1-130. The humoral immune response was evaluated by indirect ELISA. Cytokine expression levels were determined by RT-qPCR. Compared to the control group, the IgG antibody levels of animals immunized with pTARGET/ligAni and pTARGET/ligBrep plasmids associated with xanthan biopolymer were significantly higher than the control group. Additionally, there was a significant increase in IL-17 expression in animals vaccinated with pTARGET/ligBrep and xanthan.

Abstract Recombinant proteins are a suggested alternative for the diagnosis of toxocariasis. The current Escherichia coli recombinant protein overexpression system usually produces insoluble products. As an alternative, yeast such as Pichia pastoris have secretory mechanisms, which could diminish the cost and time for production. This study aimed to produce recombinant proteins in Pichia pastoris and verify their sensibility and specificity in an indirect ELISA assay. Two sequences (rTES-30 and rTES-120) of Toxocara canis excretory-secretory antigens were cloned in a pPICZαB vector and expressed in P. pastoris KM71H. Sera samples collected from human adults infected by Toxocara spp. were tested by indirect ELISA using rTES-30 and rTES-120 as antigens. Recombinant proteins were detected at 72 hours after induction, in the supernatant, as pure bands between 60~70 kDa with hyperglycosylation. Regarding diagnosis potential, recombinant antigens had high specificity (95.6%); however, sensitivity was 55.6% for rTES-30 and 68.9% for rTES-120. Further deglycosylation of the P. pastoris antigens did not seem to affect ELISA performance (p>0.05). The low sensitivity in the serodiagnosis diminished any advantage that P. pastoris expression could have. Therefore, we do not recommend P. pastoris recombinant TES production as an alternative for the diagnosis of toxocariasis.

BACKGROUND The B subunit of Escherichia coli heat-labile enterotoxin (LTB) is a potent mucosal immune adjuvant. However, there is little information about LTB's potential as a parenteral adjuvant. OBJECTIVES We aimed at evaluating and better understanding rLTB's potential as a parenteral adjuvant using the fused R1 repeat of Mycoplasma hyopneumoniae P97 adhesin as an antigen to characterise the humoral immune response induced by this construct and comparing it to that generated when aluminium hydroxide is used as adjuvant instead. METHODS BALB/c mice were immunised intraperitoneally with either rLTBR1 or recombinant R1 adsorbed onto aluminium hydroxide. The levels of systemic anti-rR1 antibodies (total Ig, IgG1, IgG2a, and IgA) were assessed by enzyme-linked immunosorbent assay (ELISA). The ratio of IgG1 and IgG2a was used to characterise a Th1, Th2, or mixed Th1/Th2 immune response. FINDINGS Western blot confirmed rR1, either alone or fused to LTB, remained antigenic; anti-cholera toxin ELISA confirmed that LTB retained its activity when expressed in a heterologous system. Mice immunised with the rLTBR1 fusion protein produced approximately twice as much anti-rR1 immunoglobulins as mice vaccinated with rR1 adsorbed onto aluminium hydroxide. Animals vaccinated with either rLTBR1 or rR1 adsorbed onto aluminium hydroxide presented a mixed Th1/Th2 immune response. We speculate this might be a result of rR1 immune modulation rather than adjuvant modulation. Mice immunised with rLTBR1 produced approximately 1.5-fold more serum IgA than animals immunised with rR1 and aluminium hydroxide. MAIN CONCLUSIONS The results suggest that rLTB is a more powerful parenteral adjuvant than aluminium hydroxide when administered intraperitoneally as it induced higher antibody titres. Therefore, we recommend that rLTB be considered an alternative adjuvant, even if different administration routes are employed.

Diagnosis of leptospirosis by PCR is hampered due to the presence of substances on biological fluids. Here, we report an immunomagnetic separation step prior to PCR which improved the detection of Leptospira spp. in blood and urine samples from dogs. It resulted in a significant improvement on sensitivity for diagnosis of canine leptospirosis.

A Enterite Necrótica Aviária (ENA) é uma enterotoxemia aguda que aparece subitamente e provoca morte rápida, afetando principalmente animais jovens. Embora seu impacto negativo na produção, devido ao aumento da conversão alimentar e da condenação de carcaças seja já conhecido, questões relacionadas à etiologia, à patogenia e ao controle desta importante enfermidade necessitam de maiores esclarecimentos. Nos últimos anos, o controle da ENA baseou-se na aplicação de antibióticos na ração animal, prática banida pelo mercado consumidor, que exigiu o desenvolvimento de novas estratégias de controle. Esta revisão aborda informações sobre a etiologia, a epizootiologia, a patogenia, o diagnóstico e o controle da doença, em especial a utilização de probióticos e vacinas como alternativas de controle da ENA.

Avian Necrotic Enteritis is an acute enterotoxaemia that appears suddenly producing rapid deaths, affecting mainly young animals. Although its negative impact in poultry production is already known, factors related to etiology, pathogenesis and control of this important disease need better clarifications. For a long time its control was based on the use of antibiotics in poultry feed, whose the use was banned by several consumer markets, requiring the development of new control strategies. Informations on the etiology, epizootiology, pathogenesis, diagnosis and control are reviewed, emphasizing the role of probiotics and vaccines as control alternatives.

A Pneumonia Enzoótica Suína (PES), causada pela bactéria fastidiosa Mycoplasma hyopneumoniae, é a doença respiratória mais importante dos suínos, responsável por enormes prejuízos à suinocultura brasileira e mundial. A elevada prevalência e o fato de pré-dispor os suínos à patógenos oportunistas tornam esta doença o alvo central de um programa de saúde de rebanho para doenças respiratórias. O conhecimento das características do agente etiológico bem como dos seus fatores de patogenicidade pode ajudar na elaboração de novas estratégias de controle da PES. O objetivo desta revisão foi discutir alguns aspectos da etiopatogenia da PES que têm implicação na imunoprofilaxia da doença e os principais resultados obtidos com vacinas de última geração avaliadas experimentalmente.

Swine Enzootic Pneumonia (SEP), caused by fastidious bacterium Mycoplasma hyopneumoniae, is the most important respiratory disease of swines, responsible for high losses to Brazilian and worldwide swine breeding. The high prevalence and the fact to predis-pose the swines to secondary pathogens make this disease the central target of a herd health program to respiratory diseases. The knowledge of the characteristics and pathogenicity factors of etiologic agent could help in the development of new strategies to control SEP. The aim of this review was to discuss some aspects of the etiopathogenesis of the SEP that have implications in the immunoprofilaxis of disease and the main results obtained with new generation vaccines evaluated experimentally.

O cumprimento da legislação que regulamenta a comercialização de alimentos e ingredientes contendo Organismos Geneticamente Modificados (OGMs) é totalmente dependente da sensibilidade e confiabilidade dos métodos de detecção e quantificação de OGMs. Na presente revisão, foram discutidos os métodos mais relevantes para tais fins, especialmente aqueles que se baseiam na detecção da proteína ou do DNA recombinante, destacando as suas principais propriedades, limitações e vantagens. A regulamentação e algumas sugestões de métodos alternativos para a detecção de OGMs também são abordadas.

The enforcement of legislation that regulates the presence of genetically modified organisms (GMOs) in food and food ingredients is totally dependent on the sensitivity and reliability of the GMO testing methods. In this review, the most relevant methods such as recombinant proteins or DNA-based methods were discussed, emphasizing their main properties, limitations and advantages. The regulamentation and some suggestions of alternative methods for the detection of GMOs were also discussed.

A susceptibilidade a antimicrobianos de trinta cepas de Moraxella bovis recuperadas entre 1974 e 2001 em surtos de Ceratoconjuntivite Infecciosa Bovina (CIB) ocorridos na Argentina, Brasil e Uruguai foi determinada pelos métodos de Kirby-Bauer e Concentração Inibitória Mínima. Nossos resultados indicam que a maioria das cepas é susceptível aos antibióticos utilizados no tratamento da CIB e que a susceptibilidade antimicrobiana da M. bovis variou conforme a região geográfica e período de recuperação.

Antibiotic susceptibility of thirty Moraxella bovis strains recovered from outbreaks of Infectious Bovine Keratoconjunctivitis (IBK) in Argentina, Brazil and Uruguay between 1974 and 2001 was determined using the Kirby-Bauer and the Minimal Inhibitory Concentration (MIC) methods. Our results suggest that most strains were susceptible to the antibiotics used in the treatment of IBK, and that the antibiotic susceptibility of M. bovis varied with the geographical region and period of recovery.

A Ceratoconjuntivite Infecciosa Bovina (CIB) continua sendo a mais importante enfermidade ocular dos bovinos da região do MERCOSUL. O agente etiológico da CIB, a bactéria Moraxella bovis, apresenta diferenças genéticas que determinam variações antigênicas e de susceptibilidade aos fármacos, que dificultam seu controle. São discutidos, neste trabalho, resultados de estudos moleculares, antigênicos e de susceptibilidade a antimicrobianos realizados com cepas isoladas durante os últimos vinte anos na região e comparados com os de outras regiões.

Infectious Bovine Keratoconjunctivitis (IBK) is still the most important ocular disease of cattle in the MERCOSUL region. The etiologic agent of IBK, the bacterium Moraxella bovis, has genetic differences responsible for antigenic and antibiotic susceptibility variability that interfere in its control. In this review, molecular, antigenic and antimicrobial susceptibility studies of strains recovered during the last 20 years in our region are discussed and compared with results obtained abroad.