Viscosity of egg white from hens of different strains fed with commercial and natural additives

Yolk color and egg white (albumen) cleanliness and viscosity are important parameters by which consumers judge the quality of eggs. This study aimed to investigate changes in albumen viscosity during storage of eggs for up to 36 days from two different commercial laying hen strains (Carijo Barbada and Isa Brown) fed a diet containing annatto (1.5 and 2.0%) or a synthetic additive without synthetic colorants (control). Analyses of humidity, albumen height, pH, viscosity, foam formation, and stability were carried out on eggs. Carijo Barbada strain had smaller albumen, lower humidity and higher egg white viscosity than Isa Brown strain; however, with storage, viscosity lowered significantly on both strains. Initially, the addition of 2.0% of annatto or a synthetic additive increased viscosity in both strains, but with storage only the control maintained longer viscosity. Lower viscosity did not change foam density and stability.

Evaluating methods for the isolation of marine-derived fungal strains and production of bioactive secondary metabolites

In the present investigation we evaluate methods for the isolation and growth of marine-derived fungal strains in artificial media for the production of secondary metabolites. Inoculation of marine macroorganisms fragments in Petri dishes proved to be the most convenient procedure for the isolation of the largest number of strains. Among the growth media used, 3% malt extract showed the best result for strains isolation and growth, and yielded the largest number of strains from marine macroorganisms. The percentage of strains isolated using each of the growth media which yielded cytotoxic and/or antibiotic extracts was in the range of 23-35%, regardless of the growth media used. Further investigation of extracts obtained from different marine-derived fungal strains yielded several bioactive secondary metabolites, among which (E)-4-methoxy-5-(3-methoxybut-1-enyl)-6-methyl-2H-pyran-2-one is a new metabolite isolated from the Penicillium paxilli strain Ma(G)K.

Trypanocidal activity of Brazilian plants against epimastigote forms from Y and Bolivia strains of Trypanosoma cruzi

Chagas disease is one of the main public health problems in Latin America. Since the available treatments for this disease are not effective in providing cure, the screening of potential antiprotozoal agents is essential, mainly of those obtained from natural sources. This study aimed to provide an evaluation of the trypanocidal activity of 92 ethanol extracts from species belonging to the families Annonaceae, Apiaceae, Cucurbitaceae, Lamiaceae, Lauraceae, Moraceae, Nyctaginaceae, and Verbenaceae against the Y and Bolivia strains of Trypanosoma cruzi. Additionally, cytotoxic activity on LLCMK2 fibroblasts was evaluated. Both the trypanocidal activity and cytotoxicity were evaluated using the MTT method, in the following concentrations: 500, 350, 250, and 100 µg/mL. Benznidazole was used for positive control. The best results among the 92 samples evaluated were obtained with ethanol extracts of Ocotea paranapiacabensis (Am93) and Aegiphila lhotzkiana (Am160). Am93 showed trypanocidal activity against epimastigote forms of the Bolivia strain and was moderately toxic to LLCMK2 cells, its Selectivity Index (SI) being 14.56, while Am160 showed moderate trypanocidal activity against the Bolivia strain and moderate toxicicity, its SI being equal to 1.15. The screening of Brazilian plants has indicated the potential effect of ethanol extracts obtained from Ocotea paranapiacabensis and Aegiphila lhotzkiana against Chagas disease.

Bioactive extracts and chemical constituents of two endophytic strains of Fusarium oxysporum

Ethyl acetate extracts of cultures grown in liquid Czapek and on solid rice media of the fungal endophyte Fusarium oxysporum SS46 isolated from the medicinal plant Smallanthus sonchifolius (Poepp.) H. Rob., Asteraceae, exhibited considerable cytotoxic activity when tested in vitro against human cancer cells. Chromatographic separation yielded anhydrofusarubin (1) and beauvericin (2) that were identified based on their ¹H and 13C NMR data. Compounds 1 and 2 showed the strongest cytotoxic activity against different cancer cell lines. Compound 2 also showed promising activity against Leishmania braziliensis. Hexanic extract of F. oxysporum SS50 grown on solid rice media also afforded a mixture of compounds that displayed cytotoxic activity against different cancer cell lines. Chemical analysis of the mixture of compounds, investigated by gas chromatography-mass spectrometry (GC-MS), showed that there was a predominance of methyl esters of fatty acids and alkanes.

Bands of respiratory rate and cloacal temperature for different broiler chicken strains

The objective of this investigation was to estimate ideal bands of respiratory rate and cloacal temperature for broiler chicken strains during the rearing period and to evaluate the influence of time of exposure on bird physiological variables under different thermal stress conditions. The research was conducted in a climatic chamber during the six weeks of the rearing period, with Avian and Cobb strains exposed to two climatic conditions (comfort and stress), in three distinct times of exposure, in three conditions (before going to the chamber; at the end of exposure time; 30 minutes after the end of exposure), in four treatments: comfort with 60 minutes of exposure; stress with 30 minutes of exposure; stress with 60 minutes of exposure; stress with 90 minutes of exposure. Bands of respiratory rate and cloacal temperature were elaborated for both strains, for each one of the weeks of the rearing period. Strains differed, regardless of treatments and conditions adopted in the research on the third, fifth and sixth weeks of life in relation to the cloacal temperature. The Cobb strain is more tolerant to thermal stress in comparison with the Avian. There was difference for both variables between comfort and stress, but time of exposure to stress did not influence the physiological response of birds, except for cloacal temperature on the second week of life.

Phenotypical characterization and adhesin identification in Escherichia coli strains isolated from dogs with urinary tract infections

Pathogenic strains of Escherichia coli are the most common bacteria associated with urinary tract infections in both humans and companion animals. Standard biochemical tests may be useful in demonstrating detailed phenotypical characteristics of these strains. Thirteen strains of E. coli isolated from dogs with UTIs were submitted to biochemical tests, serotyping for O and H antigens and antimicrobial resistance testing. Furthermore, the presence of papC, sfa, and afa genes was evaluated by PCR, and genetic relationships were established using enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). The antimicrobial that showed the highest resistance rate among the isolates was nalidixic acid (76.9%), followed by cephalotin (69.2%), sulfamethoxazole + trimethoprim (61.5%), tetracycline (61.5%), streptomycin (53.8%), ciprofloxacin (53.8%), ampicillin (46.2%), gentamicin (30.8%) and chloramphenicol (23.1%). No isolate was resistant either to meropenem or nitrofurantoin. Among the five clusters that were identified using ERIC-PCR, one cluster (A) had only one strain, which belonged to a serotype with zoonotic potential (O6:H31) and showed the genes papC+, sfa+, afa-. Strains with the genes papC-, sfa+, afa- were found in two other clusters (C and D), whereas all strains in clusters B and E possessed papC-, sfa-, afa- genes. Sucrose and raffinose phenotypic tests showed some ability in discriminating clusters A, B and C from clusters D and E.

Isolation of Microsporum gypseum in soil samples from different geographical regions of Brazil, evaluation of the extracellular proteolytic enzymes activities (keratinase and elastase) and molecular sequencing of selected strains

A survey of Microsporum gypseum was conducted in soil samples in different geographical regions of Brazil. The isolation of dermatophyte from soil samples was performed by hair baiting technique and the species were identified by morphology studies. We analyzed 692 soil samples and the recuperating rate was 19.2%. The activities of keratinase and elastase were quantitatively performed in 138 samples. The sequencing of the ITS region of rDNA was performed in representatives samples. M. gypseum isolates showed significant quantitative differences in the expression of both keratinase and elastase, but no significant correlation was observed between these enzymes. The sequencing of the representative samples revealed the presence of two teleomorphic species of M. gypseum (Arthroderma gypseum and A. incurvatum). The enzymatic activities may play an important role in the pathogenicity and a probable adaptation of this fungus to the animal parasitism. Using the phenotypical and molecular analysis, the Microsporum identification and their teleomorphic states will provide a useful and reliable identification system.

Genomic mosaicism in two strains of Dengue virus type 3

Recombination is a significant factor driving genomic evolution, but it is not well understood in Dengue virus. We used phylogenetic methods to search for recombination in 636 Dengue virus type 3 (DENV-3) genomes and unveiled complex recombination patterns in two strains, which appear to be the outcome of recombination between genotype II and genotype I parental DENV-3 lineages. Our findings of genomic mosaic structures suggest that strand switching during RNA synthesis may be involved in the generation of genetic diversity in dengue viruses.

Pathogenicity of Nc-Bahia and Nc-1 strains of Neospora caninum in experimentally infected cows and buffaloes in early pregnancy

Neospora caninum is a protozoan parasite known as an important cause of bovine abortion worldwide. Little is currently known about how different strains of N. caninum vary in their pathogenicity. In this study, we compared a Brazilian strain, Nc-Bahia, with the first isolate of this coccidian, Nc-1. Eight cows and seven buffaloes were submitted to fixed-time artificial insemination protocols for a better control of pregnancy. Group 1 was inoculated with Nc-Bahia (n=8; five cows and three buffaloes), and Group 2 was inoculated with Nc-1 (n=5; two cows and three buffaloes). One nonpregnant female of each species was left uninfected as sentinel controls for potential environmental infection. All inoculated animals received 5×108 tachyzoites of N. caninum, by intravenous route, on the 70th day of gestation. Uninfected animals remained seronegative throughout the experiment, indicating no exogenous infection, whereas all inoculated animals became seropositive to N. caninum. In Group 1, abortion was found in only one cow on 42 days postinfection (dpi; frequency of abortion=12.5 %), whilst all animals from Group 2 aborted on 35 dpi (frequency of abortion= 100 %). Parasite DNA was detected by seminested PCR in maternal, foetal and placental tissues, confirming vertical transmission in Groups 1 and 2, although histological lesions had different frequencies and degrees of severity between the groups. There was evidence of lower pathogenicity of Nc- Bahia compared to Nc-1 when used in experimental infection, as it caused fewer abortions, as well as less frequent and milder histological lesions. This was the first time Nc-Bahia has been used for experimental infection.