Contributo para o estudo das plantas vasculares endémicas da Ilha das Flores (Açores).

IV Expedição Científica do Departamento de Biologia – Flores 1989.Conforme mostra MALATO-BELIZ (1988), o número de taxa vasculares endémicos nas ilhas dos Açores varia entre um máximo de 62 taxa (ilha de S. Miguel) e um mínimo de 11 taxa endémicos na ilha Graciosa. A pequena ilha das Flores com 51 taxa endémicos ultrapassa claramente neste particular as ilhas Graciosa (11), S. Maria (35) e Corvo (37) e quase iguala em número de espécies endémicas ilhas bastante maiores como a Terceira (55) e o Faial (55). Não admira pois que em termos da relação "nº taxa endémicos/unidade de superfície (Km2)" a ilha das Flores com 0,357 end./Km2, apenas seja ultrapassada por S. Maria (0,360 end./ Km2) e pelo Corvo (2,126 end./Km2), 0 valor médio para o arquipélago situa-se apenas nos 0,184 end./Km2. A explicação para esta relativa riqueza em espécies endémicas da ilha das Flores fica sem dúvida a dever-se à grande diversidade de biótopos que ela possui e à existência de algumas manchas vegetais menos alteradas pelo homem

Prevalence of Avian Pathogenic Escherichia coli (APEC) Clone Harboring sfa Gene in Brazil

Escherichia coli sfa+ strains isolated from poultry were serotyped and characterized by polymerase chain reaction (PCR) and amplified fragment length polymorphism (AFLP). Isolates collected from 12 Brazilian poultry farms mostly belonged to serogroup O6, followed by serogroups O2, O8, O21, O46, O78, O88, O106, O111, and O143. Virulence genes associated were: iuc 90%, fim 86% neuS 60%, hly 34%, tsh 28%, crl/csg 26%, iss 26%, pap 18%, and 14% cnf. Strains from the same farm presented more than one genotypic pattern belonging to different profiles in AFLP. AFLP showed a clonal relation between Escherichia coli sfa+ serogroup O6. The virulence genes found in these strains reveal some similarity with extraintestinal E. coli (ExPEC), thus alerting for potential zoonotic risk

Current perspectives in avian salmonellosis: Vaccines and immune mechanisms of protection

Salmonellosis is one of the most prevalent foodborne diseases worldwide. Food animals have been identified as reservoirs for nontyphoid Salmonella infections. in poultry, host-specific Salmonella infections cause fowl typhoid and pullorum diseases that produce economic losses in different parts of the world. Several measures have been used to prevent and control Salmonella infections in poultry, and vaccination is the most practical measure because it avoids contamination of poultry products and by-products and prevents disease in humans. Salmonella vaccines can decrease public health risk by reducing colonization and organ invasion, including invasion of reproductive tissues, and by diminishing fecal shedding and environmental contamination. We review available information on the host-specific and non-host-specific Salmonella serotypes found in poultry and the improved understanding of the pathogenesis of and immune responses to infection. We also include some approaches based on updated publications regarding killed and live attenuated vaccines and their immune mechanisms of protection.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), BrazilFAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, Sao Paulo, Brazil) [07/53046-7

Distribution of virulence genes sefC, pefA and spvC in Salmonella Enteritidis phage type 4 strains isolated in Brazil Distribuição de genes de virulência sefC, pefA e spvC em cepas de Salmonella Enteritidis fago tipo 4 isoladas no Brasil

The distribution of virulence genes, sefC, pefA and spvC, was investigated in 110 Salmonella Enteritidis phage type 4 strains by polymerase chain reaction. Their influence in the caecal colonization and invasion of liver and spleen of one-day-old chickens was studied. Eight isolates were negative for the spvC gene, three for the pefA gene and one, for the sefC gene. These results allowed grouping the strains into four genotypes. Presence of these genes did not influence bacteria invasion in the liver and spleen of the chickens ten days after infection, although the presence of more than one fimbrial gene can be related to caecal colonization.<br>A distribuição dos genes de virulência sefC, pefA e spvC foi investigada em 110 amostras de Salmonella Enteritidis pertencentes ao fagotipo 4 através da reação em cadeia da polimerase. A influência destes genes na colonização do ceco e invasão do fígado e baço em pintinhos de um dia de idade foi avaliada. Oito amostras foram negativas para o gene spvC, três para o gene pefA e uma amostra para o gene sefC. Estes resultados permitiram a classificação das amostras em quatro genótipos. A presença destes genes não influenciou a invasão da bactéria no fígado e baço das aves dez dias após a infecção, entretanto, a presença de mais de um gene fimbrial pode ter relação com a colonização cecal

Acute heat stress impairs performance parameters and induces mild intestinal enteritis in broiler chickens: Role of acute hypothalamic-pituitary-adrenal axis activation

Studies on the environmental consequences of stress are relevant for economic and animal welfare reasons. We recently reported that long-term heat stressors (31 +/- 1 degrees C and 36 +/- 1 degrees C for 10 h/d) applied to broiler chickens (Gallus gallus domesticus) from d 35 to 42 of life increased serum corticosterone concentrations, decreased performance variables and the macrophage oxidative burst, and produced mild, multifocal acute enteritis. Being cognizant of the relevance of acute heat stress on tropical and subtropical poultry production, we designed the current experiment to analyze, from a neuroimmune perspective, the effects of an acute heat stress (31 +/- 1 degrees C for 10 h on d 35 of life) on serum corticosterone, performance variables, intestinal histology, and peritoneal macrophage activity in chickens. We demonstrated that the acute heat stress increased serum corticosterone concentrations and mortality and decreased food intake, BW gain, and feed conversion (P < 0.05). We did not find changes in the relative weights of the spleen, thymus, and bursa of Fabricius (P > 0.05). Increases in the basal and the Staphylococcus aureus-induced macrophage oxidative bursts and a decrease in the percentage of macrophages performing phagocytosis were also observed. Finally, mild, multifocal acute enteritis, characterized by the increased presence of lymphocytes and plasmocytes within the lamina propria of the jejunum, was also observed. We found that the stress-induced hypothalamic-pituitary-adrenal axis activation was responsible for the negative effects observed on chicken performance and immune function as well as for the changes in the intestinal mucosa. The data presented here corroborate with those presented in other studies in the field of neuroimmunomodulation and open new avenues for the improvement of broiler chicken welfare and production performance.FAPESP Foundation [09/51886-3]CNPq [470776/2009-9]PIBIC-CAPES [1345/2008

Overcrowding stress decreases macrophage activity and increases Salmonella Enteritidis invasion in broiler chickens

Overcrowding stress is a reality in the poultry industry. It is known that chickens exposed to long-term stressful situations present a reduction of welfare and immunosuppression. We designed this experiment to analyze the effects from overcrowding stress (Ov) of 16 animals/m2 on performance parameters, corticosterone serum levels, the relative weight of the bursa of Fabricius, IgA and IgG plasma levels, intestinal integrity, macrophage activity and experimental Salmonella Enteritidis invasion. The results of this study indicate that overcrowding stress decreased performance parameters, induced enteritis and decreased macrophage activity and the relative bursa weight in broiler chickens. When the chickens were similarly stressed and infected with Salmonella Enteritidis, there was an increase of feed conversion and a decrease of IgG plasma levels in the stressed and Salmonella-infected birds. We observed moderate enteritis throughout the duodenum of chickens stressed and infected with Salmonella. The overcrowding stress decreased the macrophage phagocytosis intensity and increased Salmonella Enteritidis counts in the livers of animals challenged with the pathogenic bacterium. Overcrowding stress via the HPA (hypothalamic pituitary adrenal) axis which is associated with an increase in corticosterone and enteritis might influence the quality of the intestinal immune barrier and the integrity of the small intestine. This effect allowed pathogenic bacteria to migrate through the intestinal mucosa, resulting in inflammatory infiltration and decreased nutrient absorption. The data strengthens the hypothesis that control of the welfare of the chickens and avoidance of stress from overcrowding in poultry production are relevant factors for the maintenance of intestinal integrity, performance and decreased susceptibility to Salmonella infection.This study was financially supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, #09/51886-3 and #09/53532-4) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, #470776/2009-9), to whom the authors wish to express their gratitude