Budgerigar

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C Venturini - One of the best experts on this subject based on the ideXlab platform.

  • characterization of sarcocystis falcatula isolates from the argentinian opossum didelphis albiventris
    Journal of Eukaryotic Microbiology, 2000
    Co-Authors: L Venturini, C Venturini
    Abstract:

    Two isolates of Sarcocystis falcatula were obtained from the lungs of Budgerigars (Melopsittacus undulatus) fed sporocysts from two naturally-infected South American opossums (Didelphis albiventris). The two isolates were designated SF-1A and SF-2A. Both isolates induced fatal infections in Budgerigars. Both isolates underwent schizogony in African green monkey kidney cells. The structure of schizonts in the lungs of Budgerigars was more variable than that observed in cell culture. The two isolates were identified as S. falcatula by the two species-specific Hinf 1 restriction fragments dervied from digestion of a PCR amplification using primers JNB33/JNB54. Thus, the South American opossum, D. albiventris, is a definitive host for S. falcatula.

  • isolation of sarcocystis falcatula from the south american opossum didelphis albiventris from argentina
    Veterinary Parasitology, 1999
    Co-Authors: L Venturini, C Venturini, W Basso, Juan Manuel Unzaga
    Abstract:

    Abstract Sarcocystis sporocysts from the intestines of four opossums (Didelphis albiventris) from Argentina were identified as Sarcocystis falcatula based on schizogonic stages and pathogenicity to Budgerigars (Melopsittacus undulatus). Seven Budgerigars fed sporocysts from the opossum feces died of acute sarcocystosis 8, 9, 11, 12, and 14 days after inoculation. Schizonts and merozoites found in the lungs and other organs of the Budgerigars were identified as S. falcatula based on structure and immunoreactivity with S. falcatula-specific antibody. Sarcocystis falcatula was also isolated in bovine monocyte cell cultures inoculated with lung tissue from a Budgerigar that died nine days after ingesting sporocysts. Two Budgerigars inoculated subcutaneously with 1 000 000 culture-derived S. falcatula died 11 and 12 days post-inoculation. This is the first report of S. falcatula infection in South America.

Yoshihiro Sakoda - One of the best experts on this subject based on the ideXlab platform.

L Venturini - One of the best experts on this subject based on the ideXlab platform.

  • characterization of sarcocystis falcatula isolates from the argentinian opossum didelphis albiventris
    Journal of Eukaryotic Microbiology, 2000
    Co-Authors: L Venturini, C Venturini
    Abstract:

    Two isolates of Sarcocystis falcatula were obtained from the lungs of Budgerigars (Melopsittacus undulatus) fed sporocysts from two naturally-infected South American opossums (Didelphis albiventris). The two isolates were designated SF-1A and SF-2A. Both isolates induced fatal infections in Budgerigars. Both isolates underwent schizogony in African green monkey kidney cells. The structure of schizonts in the lungs of Budgerigars was more variable than that observed in cell culture. The two isolates were identified as S. falcatula by the two species-specific Hinf 1 restriction fragments dervied from digestion of a PCR amplification using primers JNB33/JNB54. Thus, the South American opossum, D. albiventris, is a definitive host for S. falcatula.

  • isolation of sarcocystis falcatula from the south american opossum didelphis albiventris from argentina
    Veterinary Parasitology, 1999
    Co-Authors: L Venturini, C Venturini, W Basso, Juan Manuel Unzaga
    Abstract:

    Abstract Sarcocystis sporocysts from the intestines of four opossums (Didelphis albiventris) from Argentina were identified as Sarcocystis falcatula based on schizogonic stages and pathogenicity to Budgerigars (Melopsittacus undulatus). Seven Budgerigars fed sporocysts from the opossum feces died of acute sarcocystosis 8, 9, 11, 12, and 14 days after inoculation. Schizonts and merozoites found in the lungs and other organs of the Budgerigars were identified as S. falcatula based on structure and immunoreactivity with S. falcatula-specific antibody. Sarcocystis falcatula was also isolated in bovine monocyte cell cultures inoculated with lung tissue from a Budgerigar that died nine days after ingesting sporocysts. Two Budgerigars inoculated subcutaneously with 1 000 000 culture-derived S. falcatula died 11 and 12 days post-inoculation. This is the first report of S. falcatula infection in South America.

Almut Kelber - One of the best experts on this subject based on the ideXlab platform.

  • luminance dependence of spatial vision in Budgerigars melopsittacus undulatus and bourke s parrots neopsephotus bourkii
    Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology, 2012
    Co-Authors: Olle Lind, Tony Sunesson, Mindaugas Mitkus, Almut Kelber
    Abstract:

    Budgerigars (Melopsittacus undulatus) and Bourke's parrots (Neopsephotus bourkii) are closely related birds with different activity patterns. Budgerigars are strictly diurnal while Bourke's parrots are active in dim twilight. Earlier studies show that the intensity threshold of colour vision is similar in both species while Bourke's parrots have larger eyes with a higher density of rods than Budgerigars. In this study, we investigate whether this could be an adaptation for better spatial vision in dim light. We used two alternative forced-choice experiments to determine the spatial acuity of both species at light intensities ranging from 0.08 to 73 cd/m(2). We also determined the spatial contrast sensitivity function (CSF) for bright light in Bourke's parrots and compare it to existing data for Budgerigars. The spatial acuity of Bourke's parrots was found to be similar to that of Budgerigars at all light levels. Also the CSF of Bourke's parrots is similar to that of Budgerigars with a sensitivity peak located between 2.1 and 2.6 cycles/degree. Our findings do not support the hypothesis that Bourke's parrots have superior spatial acuity in dim light compared to Budgerigars and the adaptive value of the relatively rod-rich and large eyes of Bourke's parrots remains unclear.

  • the intensity threshold of colour vision in two species of parrot
    The Journal of Experimental Biology, 2009
    Co-Authors: Olle Lind, Almut Kelber
    Abstract:

    We have used behavioural tests to determine the intensity thresholds of colour vision in Bourke's parrots (Neopsephotus bourkii) and Budgerigars (Melopsittacus undulatus). We have also examined the relationship between these thresholds and the optical sensitivities of single photoreceptors using morphological methods. Bourke's parrots lose colour vision in brighter light (0.4 cd m(-2)) than Budgerigars (0.1 cd m(-2)) and both birds lose colour vision in brighter light ('end of civil twilight') than humans (0.02 cd m(-2),. moonlight'). The optical sensitivities of single cones are similar in both birds (Budgerigar 0.27 mu m(2) sr, Bourke's parrot 0.25 mu m(2)sr) but Bourke's parrots have more (cone to rod ratio, 1.2:1.0), thinner (2.8 mu m) and longer rods (18.5 mu m) than Budgerigars (2.1:1.0, 3.4 mu m, 13.3 mu m). Bourke's parrots thus have an eye type that, with a flexible pooling mechanism, allows for high resolution or high absolute sensitivity depending on the light conditions. The results nicely agree with the activity patterns of the birds, Bourke's parrots being active during the day and in twilight while Budgerigars are not normally active before sunrise and after sunset. However, Bourke's parrots have fewer cones than Budgerigars, which implies that a smaller number of cones are pooled within each retinal integration area. That could explain why Bourke's parrots have a higher intensity threshold of colour vision than Budgerigars. Furthermore, the study emphasises the need to expand the sensitivity measure so that photoreceptor integration units are used rather than single receptors. (Less)

Edward P Rybicki - One of the best experts on this subject based on the ideXlab platform.

  • global genetic diversity and geographical and host species distribution of beak and feather disease virus isolates
    Journal of General Virology, 2011
    Co-Authors: Arvind Varsani, Guy L Regnard, R R Bragg, Inga I Hitzeroth, Edward P Rybicki
    Abstract:

    Psittacine beak and feather disease (PBFD) has a broad host range and is widespread in wild and captive psittacine populations in Asia, Africa, the Americas, Europe and Australasia. Beak and feather disease circovirus (BFDV) is the causative agent. BFDV has an ∼2 kb single stranded circular DNA genome encoding just two proteins (Rep and CP). In this study we provide support for demarcation of BFDV strains by phylogenetic analysis of 65 complete genomes from databases and 22 new BFDV sequences isolated from infected psittacines in South Africa. We propose 94% genome-wide sequence identity as a strain demarcation threshold, with isolates sharing >94% identity belonging to the same strain, and strain subtypes sharing >98% identity. Currently, BFDV diversity falls within 14 strains, with five highly divergent isolates from Budgerigars probably representing a new species of circovirus with three strains (Budgerigar circovirus; BCV-A, -B and -C). The geographical distribution of BFDV and BCV strains is strongly linked to the international trade in exotic birds; strains with more than one host are generally located in the same geographical area. Lastly, we examined BFDV and BCV sequences for evidence of recombination, and determined that recombination had occurred in most BFDV and BCV strains. We established that there were two globally significant recombination hotspots in the viral genome: the first is along the entire intergenic region and the second is in the C-terminal portion of the CP ORF. The implications of our results for the taxonomy and classification of circoviruses are discussed.

  • A unique isolate of beak and feather disease virus isolated from Budgerigars (Melopsittacus undulatus) in South Africa
    Archives of Virology, 2010
    Co-Authors: Arvind Varsani, Guy L Regnard, Inga I Hitzeroth, Gillian K. Villiers, Robert R. Bragg, Kulsum Kondiah, Edward P Rybicki
    Abstract:

    Beak and feather disease virus (BFDV), the causative agent of psittacine beak and feather disease (PBFD) infects psittaciformes worldwide. We provide an annotated sequence record of three full-length unique genomes of BFDV isolates from Budgerigars ( Melopsittacus undulatus ) from a breeding farm in South Africa. The isolates share >99% nucleotide sequence identity with each other and ~96% nucleotide sequence identity to two recent isolates ( Melopsittacus undulatus ) from Thailand but only between 91.6 and 86.6% identity with all other full-length BFDV sequences. Maximum-likelihood analysis and recombination analysis suggest that the South African Budgerigar BFDV isolates are unique to Budgerigars, are non-recombinant in origin, and represent a new genotype of BFDV.

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