Immunogenicity of Streptococcus equi subsp. equi recombinant SeM protein and bacterin in mice / Imunogenicidade da proteína recombinante SeM de Streptococcus equi subsp. equi e da bacterina em camundongos

The infection caused by Streptococcus equi, known as strangles, affects the respiratory system of horses, causing high morbidity and rapid spread among the herd. Bacterin vaccines, composed of inactivated whole cells of S. equi, have variable efficacy and duration. Infected animals produce specific antibodies against SeM, the immunodominant antigen of S. equi. This makes it a promising target for vaccine development. In this context, the objective of this work was to evaluate a vaccine combining S. equi bacterin and recombinant SeM protein. Mice were vaccinated with bacterin (S. equi ~1.2 × 108CFU/ml); rSeM protein (20μg); bacterin-rSeM combination; or PBS (Control Group) and challenged with a suspension of S. equi, containing 10 × LD50. All vaccinated mice survived the challenge and produced anti-rSeM and anti-S. equi antibodies, which were assessed by indirect ELISA. The Control Group reached endpoint criteria 96 h after infection. These results demonstrate that a vaccine combining the S. equi bacterin with rSeM protein protects mice against strangles. This combination vaccine could potentially protect horses and overcome the limitations of currently available strangle vaccines.(AU)

A infecção causada por Streptococcus equi, denominada adenite, atinge o sistema respiratório de equinos, causando alta morbidade e rápida disseminação entre o rebanho. Vacinas bacterinas, compostas de células inteiras inativadas de S. equi apresentam eficácia e duração variáveis. Animais infectados apresentam anticorpos específicos à proteína SeM, antígeno imunodominante de S. equi, o que a torna um alvo promissor para o desenvolvimento de vacinas. Neste contexto, o objetivo deste trabalho foi avaliar uma vacina baseada na administração simultânea da bacterina e da proteína SeM recombinante. Camundongos foram vacinados com a bacterina (S. equi ~1.2 × 108CFU/ml); a proteína rSeM (20μg); a bacterina e rSeM simultaneamente; ou PBS (Grupo Controle) e, posteriormente, foram desafiados com uma suspensão de S. equi contendo 10 × LD50. Todos os animais vacinados apresentaram anticorpos anti-rSeM e contra S. equi, avaliados através de ELISA indireto, e mantiveram-se e sobreviveram ao desafio letal. O Grupo Controle atingiu critérios de endpoint 96 h após a infecção. Estes resultados demonstram que uma vacina constituída de células inteiras de S. equi com rSeM protege camundongos contra adenite, sugerindo a capacidade de proteção a equinos e, possivelmente, superando as limitações das vacinas contra adenite atualmente disponíveis.(AU)

Immunogenicity of Streptococcus equi subsp. equi recombinant SeM protein and bacterin in mice / Imunogenicidade da proteína recombinante SeM de Streptococcus equi subsp. equi e da bacterina em camundongos

The infection caused by Streptococcus equi, known as strangles, affects the respiratory system of horses, causing high morbidity and rapid spread among the herd. Bacterin vaccines, composed of inactivated whole cells of S. equi, have variable efficacy and duration. Infected animals produce specific antibodies against SeM, the immunodominant antigen of S. equi. This makes it a promising target for vaccine development. In this context, the objective of this work was to evaluate a vaccine combining S. equi bacterin and recombinant SeM protein. Mice were vaccinated with bacterin (S. equi ~1.2 × 108CFU/ml); rSeM protein (20μg); bacterin-rSeM combination; or PBS (Control Group) and challenged with a suspension of S. equi, containing 10 × LD50. All vaccinated mice survived the challenge and produced anti-rSeM and anti-S. equi antibodies, which were assessed by indirect ELISA. The Control Group reached endpoint criteria 96 h after infection. These results demonstrate that a vaccine combining the S. equi bacterin with rSeM protein protects mice against strangles. This combination vaccine could potentially protect horses and overcome the limitations of currently available strangle vaccines.(AU)

A infecção causada por Streptococcus equi, denominada adenite, atinge o sistema respiratório de equinos, causando alta morbidade e rápida disseminação entre o rebanho. Vacinas bacterinas, compostas de células inteiras inativadas de S. equi apresentam eficácia e duração variáveis. Animais infectados apresentam anticorpos específicos à proteína SeM, antígeno imunodominante de S. equi, o que a torna um alvo promissor para o desenvolvimento de vacinas. Neste contexto, o objetivo deste trabalho foi avaliar uma vacina baseada na administração simultânea da bacterina e da proteína SeM recombinante. Camundongos foram vacinados com a bacterina (S. equi ~1.2 × 108CFU/ml); a proteína rSeM (20μg); a bacterina e rSeM simultaneamente; ou PBS (Grupo Controle) e, posteriormente, foram desafiados com uma suspensão de S. equi contendo 10 × LD50. Todos os animais vacinados apresentaram anticorpos anti-rSeM e contra S. equi, avaliados através de ELISA indireto, e mantiveram-se e sobreviveram ao desafio letal. O Grupo Controle atingiu critérios de endpoint 96 h após a infecção. Estes resultados demonstram que uma vacina constituída de células inteiras de S. equi com rSeM protege camundongos contra adenite, sugerindo a capacidade de proteção a equinos e, possivelmente, superando as limitações das vacinas contra adenite atualmente disponíveis.(AU)

Establishment of a pathogenicity index for mice to Pasteurella multocida strains isolated from poultry and swine

Fowl cholera is a contagious disease that results from infection by the bacterium Pasteurella multocida. This microorganism is extensively distributed among animal species, but little is known regarding its pathogenesis and specificity to various hosts. Many studies using pathogenicity evaluation methods are subjective and difficult to quantify because they are often only involved in the observation of the lethal capacity of the agent in experimental inoculation. Due to a lack of more consistent data, this study aimed to establish a classification model of P. multocida pathogenicity in mice using strains isolated from poultry and swine. A total of 94 strains of P. multocida isolated from clinical cases of FC and from lungs of swine were tested. A volume of 0.1 mL of bacterial suspension was obtained from the concentration of 106 CFU/mL and inoculated by an intraperitoneal route in five mice. The animals were observed every six hours over seven days. In addition to the mortality observed, the time of death and gross lesions were also analyzed. The Pathogenicity Indexes obtained showed significant differences (p<0.05) according to the origin of the strains. Likewise, the number of gross lesions and isolation percentages were also varied (p<0.05) among strains isolated from poultry and swine. From the observed ratios, the isolates were grouped into three pathogenicity classes: high, medium and low. This study proposed a consistent measurement and classification of P. multocida pathogenicity. The obtained results will be used to generate other adjusted models, as well as to form the basis for disease diagnosis.(AU)

Establishment of a pathogenicity index for mice to Pasteurella multocida strains isolated from poultry and swine

Fowl cholera is a contagious disease that results from infection by the bacterium Pasteurella multocida. This microorganism is extensively distributed among animal species, but little is known regarding it’s pathogenesis and specificity to various hosts. Many studies using pathogenicity evaluation methods are subjective and difficult to quantify because they are often only involved in the observation of the lethal capacity of the agent in experimental inoculation. Due to a lack of more consistent data, this study aimed to establish a classification model of P. multocida pathogenicity in mice using strains isolated from poultry and swine. A total of 94 strains of P. multocida isolated from clinical cases of FC and from lungs of swine were tested. A volume of 0.1 mL of bacterial suspension was obtained from the concentration of 106 CFU/mL and inoculated by an intraperitoneal route in five mice. The animals were observed every six hours over seven days. In addition to the mortality observed, the time of death and gross lesions were also analyzed. The Pathogenicity Indexes obtained showed significant differences (p<0.05) according to the origin of the strains. Likewise, the number of gross lesions and isolation percentages were also varied (p<0.05) among strains isolated from poultry and swine. From the observed ratios, the isolates were grouped into three pathogenicity classes: high, medium and low. This study proposed a consistent measurement and classification of P. multocida pathogenicity. The obtained results will be used to generate other adjusted models, as well as to form the basis for disease diagnosis.

Parasitic and fungal infections in synanthropic rodents in an area of urban expansion, Aracaju, Sergipe State, Brazil / Infecções parasitárias e fúngicas em roedores sinantrópicos coletados em área de expansão urbana, Aracaju, Estado do Sergipe, Brasil

This study analysed the prevalence of parasitic and fungal infections in rodents in an area of urban expansion, Aracaju, Brazil. Traps were placed in the area from December 2011 to January 2013. Blood samples, faeces and hair were collected from the animals. We collected a total of 47 rodents; 44 were Rattus rattus, and 3 were Mus musculus. Parasitological evaluation revealed the cestode Hymenolepis diminuta infection in both rodent species. The nematodes Aspiculuris tetraptera and Syphacia obvelata were found in M. musculus, and the commensal Entamoeba coli was found in R. rattus. We observed that 69.2% of the R. rattus and 33.3% of the M. musculus were infected with the haemoparasite Babesia sp. The differential leukocyte count revealed normal (72.3%), neutrophilic (15.9%) and lymphocytic (11.4%) profiles. The evaluation showed the following species of fungi in the rodents: Aspergillus sp. (77.1%), Penicillium sp. (28.6%), Cladosporium sp. (14.3%), Mucor sp. (14.3%), Curvularia sp. (8.6%), Acremonium sp. (8.6%), Chrysosporium sp. (2.9%), Syncephalostrum sp. (2.9%), Alternaria sp. (2.9%), Trichophyton sp. (2.9%) and Scopulariopsis sp. (2.9%). The parasites and fungi found in rodents are potentially zoonotic, and the presence of these household animals demonstrates their potential role as reservoirs and disseminators of fungal and parasitic infections.(AU)

Este estudo objetivou analisar a prevalência de infecções parasitárias e fúngicas em roedores em área de expansão de Aracaju, Brasil. Foram colocadas armadilhas com iscas no período de dezembro de 2011 a janeiro de 2013. Os animais coletados foram submetidos à coleta de amostras sanguíneas, fecais e de pelos. Foram coletados 47 roedores sendo 44 Rattus rattus e três Mus musculus e a avaliação parasitológica revelou infecção pelo cestódeo Hymenolepis diminuta em ambas as espécies, pelos nematódeos Aspiculuris tetraptera e Syphacia obvelata em M. musculus e pelo enterocomensal Entamoeba coli em R. rattus. Observou-se também que 69,2% de R. rattus e 33,3% de M. musculus estavam infectados pelo hemoparasita Babesia sp. A contagem diferencial dos leucócitos revelou perfil normal (72,3%), neutrofílico (15,9%) e linfocitário (11,4%). A avaliação micológica apresentou variabilidade qualitativa de fungos: Aspergillus sp. (77,1%), Penicillium sp. (28,6%), Cladosporium sp. (14,3%), Mucor sp. (14,3%), Curvularia sp. (8,6%), Acremonium sp. (8,6%), Chrysosporium sp. (2,9%), Syncephalostrum sp. (2,9%), Alternaria sp. (2,9%), Trichophyton sp. (2,9%) e Scopulariopsis sp. (2,9%). Os parasitas e fungos encontrados nos roedores são potencialmente zoonóticos sendo que a presença destes animais no peridomicílio evidencia o seu papel como reservatórios e disseminadores de infecções parasitárias e fúngicas.(AU)

Infection of sparrows (Passer domesticus) and different mice strains with Lawsonia intracellularis / Infecção de pardais (Passer domesticus) e diferentes linhagens de camundongos com Lawsonia intracellularis

The susceptibility of sparrows (Passer domesticus) and strains of mice (Swiss, BALB/c, C-57 and DB-A) to Lawsonia intracellularis infection was studied. Thirty-two sparrows were inoculated with pure culture of L. intracellularis and eleven received sham inoculum. Feces were collected on -1, 7, 14 and 21 days post infection (dpi) for detection of L. intracellularis by PCR. After 21 days, all sparrows were euthanized and the tissues processed for histology and immunohistochemistry (IHC). One hundred sixty mice of four different strains (n=40, per strain) were used. For each mouse strain, 16 animals received mucosa homogenate from a pig infected with L. intracellularis, 16 received pure culture of L. intracellularis and eight animals received sham inoculum. Two control and four inoculated mice from each group were euthanized on 7, 14, 21 and 28 dpi. Sections of intestine were collected for histologic analysis and IHC and pooled feces were collected for L. intracellularis PCR. None of the sparrows had any histologic lesions characteristic of proliferative enteropathy or antigen labeling by IHC. All sparrow fecal samples were negative by PCR. All mice strains studied had histopathological lesions typical of PE and IHC labeling consistent with L. intracellularis infection, especially those animals inoculated with pure culture. The most severe lesions were observed in DB-A and Swiss mice. Fecal shedding was detected in all mice strains, with peak at 14 dpi. We conclude that sparrows do not seem to be relevant in the epidemiology of L. intracellularis. The results showed variations in the lesions among the four mice strains used.(AU)

A susceptibilidade de pardais (Passer domesticus) e linhagens de camundongos (Swiss, BALB / C, C-57 e DB-A) à infecção por L. intracellularis foi testada. Trinta e dois pardais foram inoculados com cultura pura de L. intracellularis e onze receberam placebo. As fezes foram coletadas nos dias -1, 7, 14 e 21 após a infecção (dpi) para a detecção de Lawsonia intracellularis por PCR. Após 21 dias, todos os pardais foram eutanasiados e os tecidos processados para a realização da histologia e imuno-histoquímica (IHQ). Cento e sessenta camundongos de quatro linhagens diferentes (n=40, por linhagem) foram utilizados. Para cada linhagem de camundongo, 16 receberam homogeneizado de mucosa preparado a partir de um suíno infectado com L. intracellularis, 16 receberam cultura pura de L. intracellularis e oito animais receberam placebo. Dois camundongos controle e quatro camundongos inoculados de cada grupo foram sacrificados aos 7, 14, 21 e 28 dpi. Seções de intestino foram coletadas para análise histológica e IHQ e amostras de fezes foram coletadas para a realização da PCR para detecção de L. Intracellularis. Nenhum dos pardais apresentou lesões histológicas características da enteropatia proliferativa ou marcação positiva por meio da IHQ. As amostras de fezes dos pardais foram negativas na PCR. Todas as linhagens de camundongos estudadas tinham lesões histopatológicas típicas de enterite proliferativa e IHQ positiva para a infecção por L. intracellularis, especialmente aqueles animais inoculados com a cultura pura. As lesões mais graves foram observadas em camundongos DB-A e Swiss. A eliminação fecal foi detectada em todas as linhagens de camundongos, com pico 14 dpi. Conclui-se que os pardais não são relevantes na disseminação da L. intracellularis. Os resultados mostraram variações nas lesões entre as quatro linhagens de camundongos utilizadas, indicando o potencial risco que os camundongos representam na transmissão de L. Intracellularis.(AU)

Detecção de Proteus mirabilis nas fezes de camundongos spf / /Detection of Proteus mirabilis in specifc pathogen free mice feces

O presente estudo teve como objetivo apresentar os resultados de pesquisa de positividade do microorganismo Proteus mirabilis em camundongos das linhagens C57BL/6, BALB/c e BALB/c Nude, originários do setor de criação de camundongos livres de patógenos específicos (SPF) do Centro de Bioterismo da Faculdade de Medicina da USP e relatar a importância do isolamento deste microorganismo em colônias de animais. Para tanto, amostras de fezes de 71 camundongos da linhagem C57BL/6, 48 camundongos da linhagem BALB/c e 26 camundongos da linhagem BALB/c Nude, foram semeadas em meios específicos para bactérias gram negativas e diagnosticado no Enterokit B da Probac do Brasil. Nossos resultados mostraram que, as linhagens de camundongos C57BL/6, BALB/c e BALB/c Nude apresentaram P.mirabilis nas fezes, nas porcentagens de 80,3%, 62,5% e 73,1% respectivamente, sendo inadequadas para utilização em protocolos experimentais das áreas de radiobiologia, imunologia, oncologia e cirurgias experimentais invasivas, por interferirem potencialmente nos resultados destas áreas. CEUA nº 251/11.

This study aimed to present the positive results of Proteus mirabilis research from strains inbred mice C57BL/6, BALB/c and BALB/c Nude, originating from the sector of Specific Pathogen Free (SPF) mice - Animal Facilities of Faculdade de Medicina (USP – University of São Paulo) and report the importance of isolation of this microorganism in colonies of animals. For this, stool samples from: 71 C57BL/6, 48 BALB/c and 26 BALB /c Nude inbred mice, were inoculated in cultural bacteria specific media and diagnosed in the B Enterokit Probac-Brasil. Our results showed that the strains of C57BL/6, BALB/c and BALB/c Nude presented P.mirabilis in stool, percentages of 80.3%, 62.5% and 73.1% respectively, being unsuitable for use in experimental protocols in the fields of radiobiology, immunology, oncology, and experimental invasive surgeries by interfering mainly on the results of these areas. CEUA No. 251/11.

Detecção de Proteus mirabilis nas fezes de camundongos spf / /Detection of Proteus mirabilis in specifc pathogen free mice feces

O presente estudo teve como objetivo apresentar os resultados de pesquisa de positividade do microorganismo Proteus mirabilis em camundongos das linhagens C57BL/6, BALB/c e BALB/c Nude, originários do setor de criação de camundongos livres de patógenos específicos (SPF) do Centro de Bioterismo da Faculdade de Medicina da USP e relatar a importância do isolamento deste microorganismo em colônias de animais. Para tanto, amostras de fezes de 71 camundongos da linhagem C57BL/6, 48 camundongos da linhagem BALB/c e 26 camundongos da linhagem BALB/c Nude, foram semeadas em meios específicos para bactérias gram negativas e diagnosticado no Enterokit B da Probac do Brasil. Nossos resultados mostraram que, as linhagens de camundongos C57BL/6, BALB/c e BALB/c Nude apresentaram P.mirabilis nas fezes, nas porcentagens de 80,3%, 62,5% e 73,1% respectivamente, sendo inadequadas para utilização em protocolos experimentais das áreas de radiobiologia, imunologia, oncologia e cirurgias experimentais invasivas, por interferirem potencialmente nos resultados destas áreas. CEUA nº 251/11.(AU)

This study aimed to present the positive results of Proteus mirabilis research from strains inbred mice C57BL/6, BALB/c and BALB/c Nude, originating from the sector of Specific Pathogen Free (SPF) mice - Animal Facilities of Faculdade de Medicina (USP University of São Paulo) and report the importance of isolation of this microorganism in colonies of animals. For this, stool samples from: 71 C57BL/6, 48 BALB/c and 26 BALB /c Nude inbred mice, were inoculated in cultural bacteria specific media and diagnosed in the B Enterokit Probac-Brasil. Our results showed that the strains of C57BL/6, BALB/c and BALB/c Nude presented P.mirabilis in stool, percentages of 80.3%, 62.5% and 73.1% respectively, being unsuitable for use in experimental protocols in the fields of radiobiology, immunology, oncology, and experimental invasive surgeries by interfering mainly on the results of these areas. CEUA No. 251/11.(AU)