1,720,974 research outputs found
Chlamydia psittaci infection in canaries heavily infested by Dermanyssus gallinae
Get PDFDermanyssus gallinae is a haematophagous ectoparasite responsible for anemia, weight loss, dermatitis and a decrease in egg production. Dermanyssus gallinae may play a role in the modulation of the host immune system, maybe predisposing the host to some bacterial infections such as chlamydiosis. This is an important zoonosis. Humans are exposed to Chlamydia psittaci through inhalation of the agent dispersed from the infected birds. In this study, a syndrome observed in an aviary of canaries was investigated. A heavy infestation by D. gallinae was reported. Simultaneously, a C. psittaci infection was molecularly confirmed in the canaries. Combined therapy was applied successfully. The association of C. psittaci with the examined mites has been confirmed. Therefore, we think that D. gallinae have played a role in the spreading of C. psittaci infection among the canaries. Moreover, D. gallinae could have played an important role predisposing the canaries to the development of chlamydiosis, by inducing anemia and debilitation. The control of mites in the aviaries may represent a crucial step for the prevention of important infection such as chlamydiosis in birds and humans
Dermanyssus gallinae in layer farms in Kosovo: a high risk for salmonella prevalence
Get PDFBackground
The poultry red mite (PRM), Dermanyssus gallinae (D.g.) is a serious ectoparasitic pest of poultry and potential pathogen vector. The prevalence of D. g. and the prevalence of Salmonella spp. within mites on infested laying poultry farms were investigated in Kosovo.
Findings
In total, 14 populated layer farms located in the Southern Kosovo were assessed for D. g. presence. Another two farms in this region were investigated 6 months after depopulation. Investigated flocks were all maintained in cages, a common housing system in Kosovo. A total of eight farms were found to be infested with D. g. (50%) at varying levels, including the two depopulated farms. The detection of Salmonella spp. from D. g. was carried out using PCR. Out of the eight layer farms infested with D. g., Salmonella spp. was present in mites on three farms (37.5%).
Conclusions
This study confirms the high prevalence of D. g. in layer flocks in Kosovo and demonstrates the link between this mite and the presence of Salmonella spp. on infested farms
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Investigation into the presence of acaricide residues in laying hens naturally infected by red mite Dermanyssus gallinae.
No full textSurvey on the presence of Salmonella gallinarum in Dermanyssus gallinae in intensive poultry farms
No full textSalmonella enterica subsp. enterica ser Gallinarum is the causative agent of fowl typhoid. The disease
represents a major concern among industrial poultry farms, causing heavy economic losses due to its
detrimental effects on productivity and animal welfare. The pathogen is highly persistent and its eradication
from an infected farm is often difficult. A possible cause of its survival may be the association with parasites,
such as the poultry red mite Dermanyssus gallinae. The latter is widespread among European poultry farm,
with infestation rates raising up to 90%.
This study is aimed to evaluate the association among D. gallinae and S. gallinarum in the Italian intensive
poultry farms.
Seventy-four samples of mites were collected from 62 intensive poultry farms. Up to 100 mites per
sample underwent to homogenization and DNA extraction. The extracted DNA was used as template in a
seminested-PCR-based protocol, already proved to be sensitive and specific.
Four samples out of 74 (5.41%) resulted positive for the presence of S. gallinarum. Three positive samples
came from different laying hen farms, while the other came from a broiler parent farm.
Such data confirm the association between D. gallinae and S. gallinarum, once again evidencing the
potential vectorial role of the mite for the bacterial pathogen. Furthermore, they suggest that D. gallinae
may act as a reservoir of S. gallinarum, as it could be hosted by the mite even during the sanitary breaks,
which are carried out in order to eradicate fowl typhoid from an infected poultry far
Characterization of Dermanyssus gallinae (Acarina: Dermanissydae) by sequence analysis of the ribosomal internal transcribed spacer regions
No full textIn the present work mites previously identified as Dermanyssus gallinae De Geer (Acari, Mesostigmata) using morphological keys were investigated by molecular tools. The complete internal transcribed spacer 1 (ITS1), 5.8S ribosomal DNA, and ITS2 region of the ribosomal DNA from mites were amplified and sequenced to examine the level of sequence variations and to explore the feasibility of using this region in the identification of this mite. Conserved primers located at the 3’end of 18S and at the 5’start of 28S rRNA genes were used first, and amplified fragments were sequenced. Sequence analyses showed no variation in 5.8S and ITS2 region while slight intraspecific variations involving substitutions as well as deletions concentrated in the ITS1 region. Based on the sequence analyses a nested PCR of the ITS2 region followed by RFLP analyses has been set up in the attempt to provide a rapid molecular diagnostic tool of D. gallina
Evaluation of the poultry red mite (Dermanyssus gallinae, Acarina: Dermanyssidae) susceptibility to some acaricides in field populations from Italy
No full textVariations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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