Maristela Lovato Flôres

Fixação de nitrogênio e produção de ácido indolacético in vitro por bactérias diazotróficas endofíticas

O objetivo deste trabalho foi isolar e quantificar bacterias diazotroficas associadas a raizes de arroz, e avaliar a producao de acido indolacetico e o potencial de fixacao biologica de nitrogenio dessas bacterias, a fim de selecionar isolados promissores para inoculacao em plantas. Bacterias fixadoras de nitrogenio, habitantes do interior das raizes de cultivares de arroz do Rio Grande do Sul, foram isoladas e quantificadas em nove cultivares. Raizes de arroz superficialmente esterilizadas foram maceradas e introduzidas em meios de crescimento, elaborados sem fonte de nitrogenio e em condicoes semi-solidas. Entre os 58 isolados nos meios NFb, LGI e LGI-P, foram escolhidos UFSM-BD-02-06, UFSM-BD-08-06, UFSM-BD-14-06, UFSM-BD-20-06, UFSM-BD-26-06, UFSM-BD-31-06, UFSM-BD-36-06, UFSM-BD-42-06, UFSM-BD-48-06, UFSM-BD-54-06. Avaliaram-se a fixacao biologica de nitrogenio e a producao de acido indolacetico in vitro, pelos metodos Kjeldahl e colorimetrico, respectivamente. Azospirillum brasilense e A. lipoferum apresentam maiores valores para N total, 41,08 e 46,82 µg mL-1, respectivamente. A. brasilense e UFSM-BD-31-06 sao os maiores produtores de acido indolacetico, 41,09 mg mL-1 e 13,47 µg mL-1, respectivamente.

Polymerase chain reaction (PCR) for the detection of Salmonella in artificially inoculated chicken meat

The aim of this study was to develop a polymerase chain reaction (PCR) protocol for the detection of Salmonella in artificially contaminated chicken meat. Tests were performed with different dilutions of Salmonella Typhimurium or Salmonella Enteritidis cells (10(-7), 10(-8) or 10(-9) CFU/mL) inoculated in chicken meat samples, in order to establish the limits of detection, incubation times (0, 6, 8 and 24 hours of pre-enrichment in PBW 1%) and three DNA extraction protocols (phenol-chloroform, thermal treatment and thermal treatment and Sephaglass). The assay was able to detect until 10(-9) CFU/mL of initial dilution of Salmonella cells inoculated in chicken meat, which allows detection of Salmonella within 48 hours, including 24 hours of pre-enrichment and using the phenol-chloroform DNA extraction protocol. As the results are obtained in a shorter time period than that of microbiological culture, this procedure will be useful in the methodology for detection of Salmonella in chicken.

Pulmonary aspergillosis outbreak in Rhea americana in Southern Brazil

Commercial raising of rheas is currently in expansion in the south of Brazil,and many diseases previously restricted to other avian species are currentlyemerging on rhea farms, especially as a result of careless management of theseanimals. The objective of the present article is to report a pulmonary aspergillosisoutbreak that occurred in great rhea (Rhea americana) in the south of Brazil.About 50 birds aged 30 to 60 days died suddenly and one of them was submittedto autopsy which revealed the presence of white caseous nodules 0.5 mm in diameter occupying 95% of the lung area. One lung was sent to the FederalUniversity of Santa Maria for histopathological and mycological analyses.Histopathological analysis revealed multifocal areas with necrosis and inflammatoryinfiltrates and the presence of fungal hyphae, giant cells and fibrous tissue proliferationat the periphery. Aspergillus fumigatus was recovered as pure culture from all culture media. This appears to be the first report of aspergillosis among great rheain Brazil and the second in the world.

Controle da infecção por Salmonella Enteritidis em frangos de corte com ácidos orgânicos e mananoligossacarídeo

The objective of this study was to evaluate the effect of two organic acids (formic acid and propionic acid) and of one mannanoligosaccharide added to the diet to control the intestinal infection caused by Salmonella Enteritidis (SE) in broilers. In this study of 39 days 150 birds were used, with one day of age, of the Cobb lineage, both sexes and free of SE. They were divided in 6 different treatments (T) with 25 birds each, where: T1 (no infection), T2 (organic acids + no infection), T3 (organic acids + mannanoligosaccharide and no infection), T4 (organic acids and infection with SE) T5 (organic acids + mannanoligosaccharide + and infection with SE) T6 (infection with SE). After housing, the chicken litter was instilled on the 4th day with SE and every seven days, five birds from each group were euthanized through cervical dislocation. The necropsy was performed and also the bacteriological exams to detect SE, using the feces collected over the chicken litter of the groups, bacteriological analysis of the cecal tonsils was done as well. On the 18th day only 60% of birds were infected in treatments T4 and T5; on the 25th day, 40% of birds in T4 and 20% in the T5 were infected; on the 32nd day, 100% of tested samples were negative in both treatments. The T6 group was 100% positive until the 32nd day, but on the 39th day, it got reduced in 20% of the number of infected animals. In the experimental conditions of this study, the organic acids and the mannanoligosaccharide added to the diet contributed to control the infection caused by SE.

Microbiota cloacal aeróbia de cracídeos cativos no Rio Grande do Sul e sua susceptibilidade a antimicrobianos

Cracids are wildlife Galliformes which inhabits the Americas tropical forests. Fifty one cloacal swabs were collected from 10 different species of captive cracids from the Rio Grande do Sul State during 2007. The cloacal swab samples were submitted to bacterial isolation, identification and, subsequently; antimicrobial susceptibility testing. Ninety three bacterial isolates were obtained from the cracid population examined. The most prevalent among the isolates were Escherichia coli, and bacteria from the Staphylococcus and Streptococcus genera. All samples tested in this study were negative for Salmonella spp. The antimicrobial susceptibility tests showed that none of the 93 strains presented resistance to the antimicrobial imipinem. In addition, the lower percentages of resistance were observed against cloranfenicol and ciprofloxacine. The bacteria genus and species with the highest percentage of resistance to the different antimicrobials examined were E. coli, Serratia marcescens, Staphylococcus spp. and Streptococcus spp. In conclusion, the data presented in this article demonstrate that the cloacal microbiota of the reported cracid population is composed of several bacterial genera and species and multi-drug resistance may be a problem for the future, since some strains showed elevated percentage of resistance against several different antimicrobials.

Prevalência de anticorpos para Toxoplasma gondii em emas (Rhea americana) em diferentes criatórios do Estado do Rio Grande do Sul

Neste trabalho foram analisados 74 amostras de soro de emas provenientes de dez criatorios diferentes localizados no Estado do Rio Grande do Sul. O exame sorologico realizado foi hemaglutinacao indireta, de acordo com as normas preconizadas pelo fabricante do Kit utilizado, para deteccao e quantificacao de anticorpos contra Toxoplasma gondii. A titulacao minima considerada foi a diluicao maior ou igual a 1/8. A analise dos resultados demonstrou que uma pequena quantidade (8,10%) destes animais estava infectada pelo parasita, no entanto 40% das propriedades onde as amostras foram obtidas apresentaram animais reagentes. Esses resultados salientam a importância de um estudo mais aprofundado sobre a susceptibilidade imunologica destas ratitas ao agente da toxoplasmose.

Análise da contaminação por Salmonella em ovos do tipo colonial através da reação em cadeia da polimerase

The identification of salmonella infection in commercial poultry has been one of the strong points of prophylaxis and consequent reduction of salmonellosis outbreaks in humans associated to consumption of eggs, considering that the analysis of the eggs can be one more point of detection of infection, which for many times appear without clinical signs. The Polymerase Chain Reaction (PCR) seems to be a useful strategy for Salmonella detection, because various authors have used the PCR to verify the presence of bacteria in meat, feces, tissues, blood, milk and eggs, with different methods of manipulation of samples. We have analyzed 360 eggs from ten farms, producers of free range-eggs, in the district of Camobi, in Santa Maria n RS n Brasil. The eggs were grouped in pools of six, totaling sixty samples. The bacteriological exam was done in compliance with the method preconized by the technical rules and the method for extraction of DNA was by phenol-chloroform. The PCR was performed for the amplification of a 284 bp DNA fragment. The analysis of the results do not show significant difference between the PCR and the bacteriological exam. All positive samples in the

Cryptosporidium sp. em intestinos, bursa de Fabricius e traquéia de frangos (Gallus gallus sp)

Parasites of the gennus Cryptosporidium infect several animal species.The disease resultant is the criptosporidiosis, an important zoonosis spreaded worldwide. In poultry, the infection has been reported in several species. This study goal was to identify the parasite presence in 208 bursa of Fabricius samples, 208 intestine and 208 of trachea, collected at chicks (Gallus gallus sp) of different ages, killed at three farms in Santa Maria city, Rio Grande do Sul State, Brazil. Three printings of each sample were done,on glass slides colored through the Ziehl Neelsen technique modified with Dimetil Sulfoxido (DMSO), Ziehl Neelsen modifed by Henriksen and Pohlens (HP), Ziehl Neelsen (ZN) and Kinyoun (K), completing 1872 printings analyzed in optical microscopy (1000 x). At this final number, at the different colorations done, oocysts of the parasite Cryptosporidium sp. were viewed in 18 trachea printings, 42 of bursa de Fabricius and 29 of intestine, resulting positive, 89 printings. From these 89, 44 were identified through the technique DMSO, 32 through HP, three through ZN and 10 through K. Cryptosporidium sp. parasites oocysts were found with more frequency from printings of bursa the Fabricius. The coloration method, of those utilized, was the one which had the better visualization of the oocysts was the DMSO.

Anticorpos contra vírus em galinhas de terreiro do Estado do Rio Grande do Sul, Brasil

The backyard poultry are not included in the biosecurity system applied in commercial flocks in Brazil. To investigate the presence of antibodies to specific viral pathogens in this population, blood samples were collected from 867 non-vaccinated birds, from 60 flocks in 22 counties of the Rio Grande do Sul State, Brazil. The samples were tested to detect antibodies against infectious bronchitis virus (IBV), avian reovirus (ARV) and infectious bursal disease virus (IBDV), through the virus neutralization test. Antibodies to IBV were detected in 65% (564/867), against ARV in 21.6% (187/867), and against IBDV in 80.2% (695/867) of the samples. All the flocks had chickens positive to IBV and IBDV antibodies, and 88.3% of them harbored antibodies to ARV. The results show the presence of these viruses in backyard poultry from the central region of the State. It also indicates the need for additional studies aimed to evaluate the real importance of these infections for this type of flocks.

Eletroforese das proteínas plasmáticas em emas (Rhea americana) de diferentes faixas etárias

Breeding of rheas has been growing throughout Brazil. However, there is still lack of information about this species and of professionals specialized in the area. This study was aimed at verifing the differences in plasmatic electrophoresis (agarosis gel) at different ages of rheas (Rhea americana). Fourty-five rheas were separated into 4 groups: group 1: (n=10), 15 day old animals; group 2: (n=10), 30 day old animals; group 3: (n=10), 45 day old animals; group 4: (n=15), 1 year old animals. The electrophoretic values analyzed presented homogeneity within each age group. There were differences between different age groups in the values of total plasmatic protein, albumin, globulins and the albumin/globulin relation. There was also a difference between age groups for fractions a1, a2, s and g. These results demonstrated that the electrophoretic profile of rheas undergoes variations according to the age analyzed. Therefore, more attention, is needed by the professionals in the interpretation of this type of examination. The parameters obtained from this study show a divergence of values, when compared to from those obtained from other avian species, showing up the importance of understanding these values in this species.