376 research outputs found
Aerobic and microaerophilic bacteria isolated from Psoroptes cuniculi.
No full textThe bacterial flora of Psoroptes cuniculi removed from nine naturally infested rabbits was investigated. Mites were collected in sterile glass tubes; half of the mites were surface sterilised, the others were not. All mites were crushed using sterile glass pestles, placed in Buffered Peptone Broth, smeared on to several culture media, by glass rods, and incubated at 37 degrees C for 48 hours, aerobically and/or in 5% CO2. Representative colonies were removed and streaked on to several selective media. Different colour changes of the selective media used, macro and microscopic morphology, ability to grow aerobically, Gram staining, and several biochemical tests evaluated with API test strips, were used for bacterial identification. Staphylococcus aureus, Serratia marcescens and S. odorifera were the bacteria isolated from surface sterilised mites
Relationship between Psoroptes cuniculi and the internal bacterium Serratia marcescens.
No full textThe bacterium Serratia marcescens isolated from surface-sterilised Psoroptes cuniculi was found sensitive to the antibiotic Amikacin. Mites placed in this antibiotic for 48-72 h and then washed by centrifugation were found to be alive and S. marcescens-free. Two experimental infestations were undertaken in order to verify the ability of the S. marcescens-free mites to infect and to give ear skin lesions in healthy rabbits and to evaluate the differential ability of the S. marcescens-free and S. marcescens-infected mites to give ear skin lesions. All rabbits were found to be infested, but only rabbits infested with S. marcescens-free mites presented crusts in their ears, whereas mites and/or eggs were only detected in the ear cerumen of all rabbits infested with S. marcescens-infected mites. S. marcescens was isolated only from P. cuniculi mites taken from these latter rabbits. Results indicate that P. cuniculi mites do not need S. marcescens to live and to be able to infest a healthy rabbit. In addition, S. marcescens was not isolated from eggs and newly born larvae of S. marcescens-infected P. cuniculi, demonstrating that in a population of P. cuniculi this bacterium is not transmitted transovarially
Isospora atrata (Apicomplexa, Eimeridae): a new coccidium isolated from Carduelis atrata (Passeriformes, Fringillidae)
No full textLarge numbers of coccidian oocysts belonging to the genus Isospora were obtained from the intestinal contents of 98 Carduelis atrata imported into Italy from South America during the months of August through December 1994. The oocysts are subspherical and average 21 X 20.3 mu m (19.4-23.5 mu m X 18.5-22 mu m), have a bilayered wail, and an oval polar granule (rarely two). The sporocysts are elliptical and measure 18.8 mu m X 10.3 mu m (17.5-18.94 mu m X 9.5-11.0 mu m). The Stieda body protrudes slightly from the end of the sporocyst. A large sporocyst residuum is present, consisting of many granules that may be in a compact mass or scattered. Since this Isospora sp.does not resemble any other species of Isospora previously described from birds of the genus Carduelis, it has been named Isospora atrata n. sp. after the host. Disseminated asexual stages were found in mononuclear cells derived from formalin-fixed post mortem material, suggesting this coccidian may represent an Atoxoplasma-like parasite. Four coccidia-free Serinus canarius L. cohabitated for a lone period (4 mo) with infected C. atrata but oocysts were never found in the stool of these birds
Formazione on line: Coerenza interna e validità convergente della scala del senso di comunità in corsi online
No full textIl Senso di Comunità (SdC), ovvero la percezione di similarità e interdipendenza che si
sviluppa tra i membri di un gruppo, è considerato nella formazione on line uno dei
fattori che contribuiscono significativamente alla qualità dell’apprendimento e alla
soddisfazione degli studenti. La sua valutazione può essere indicata anche per
identificare le condizioni organizzative che possono effettivamente supportare il SdC,
come ad esempio la modalità di interazione (asincrona vs. asincrona e sincrona) e le
caratteristiche del contesto del corso (ad. es. totalmente on-line vs. blended). In accordo
al modello di McMillan e Chavis (1986), è stata recentemente predisposta la Scala del
SdC in Corsi on line (SSCC; Perrucci et al., 2008, 2009). Con la presente indagine si è
voluto verificarne coerenza interna e validità convergente-divergente rispetto a test che
misurano il SdC e costrutti affini ma distinti.
Duecentottantasei frequentanti di corsi on line, casualmente suddivisi in due sub-gruppi
(1 e 2) entro ogni corso, hanno compilato l’SSCC e altri due questionari già validati e
opportunamente adattati dagli Autori della presente indagine al contesto della
formazione on line: Scala Italiana del Senso di Comunità (Prezza et al., 1999) e Scala
Multidimensionale del Sostegno Sociale Percepito (Zimet et al., 1988), sub-gruppo 1;
Classroom Community Scale (Rovai, 2002) e Questionario sull’Identità Sociale
(Cameron, 2004), sub-gruppo 2.
Il coefficiente di alfa di Cronbach e i pattern di correlazioni tra l’SSCC e le altre scale
permettono di affermare che l’SSCC è attendibile nel misurare il SdC in corsi on line e
valido nel discriminarlo da costrutti simili. Ulteriori indagini sulle proprietà
psicometriche consentiranno di verificare se la struttura fattoriale dell’SSCC è in
accordo con le dimensioni ipotizzate dal modello di McMillan e Chavis (1986)
Immunocytochemistry of Psoroptes cuniculi stained by sera from naive and infested rabbits: preliminary results.
No full textImmunocytochemistry was used to identify possible target antigens in the digestive system of Psoroptes cuniculi. Sera from three recently acutely infested rabbits, from rabbits with a mild long lasting infestation, and from a rabbit with repeated mite infestations and no longer able to maintain a population of P. cuniculi were used to determine any antibody specificity to the mite digestive system. The reactivity of these sera was compared with sera from three un-infested animals. The different pool of sera targeted different mite antigens; in particular, sera from the resistant rabbit and the chronically infested rabbits reacted with gut cells, faecal material and cuticle, while sera from the recently infested rabbits reacted with gut contents, faecal material and cuticle of the parasites but not with gut cells. Finally, sera from un-infested rabbits did not demonstrate any specificity to P cuniculi antigens reacting only with mite gut contents in a weak manner. These preliminary data suggest the presence of antibodies induced in the host blood by infection, which act against the parasite by binding to antigen at the surface of its gut
Isospora tibetana (Apicomplexa,Eimeridae): a new coccidium isolated from Serinus (Carduelis) thibetanus (Passeriformes, Fringillidae)
No full text- …
