29 research outputs found
Pathogenicity and chemotherapy of Plasmodium durae in experimentally infected domestic turkeys
Only 3 out of 8 South African isolates of Plasmodium durae used in 524 turkeys in 161 passages caused
approximately 50% mortality, a further 3 produced approximately 10% mortality while 2 were found to
be apathogenic. Exoerythrocytic schizonts were the main pathogenic stage. In most survivors the effect
on mass gains was minimal.
Twelve drugs currently available for use in poultry, as well as chloroquin phosphate, were tested for their
activity against experimental infections with Plasmodium durae in domestic turkeys. While chloroquin
phosphate showed a certain degree of effectivity, Amprolium, Amprolium + Ethopabate, Maduramycin,
Toltrazuril, Metronidazole, Furazolidone, Enrofloxacin and Sulfamethoxypyridazine + Trimethoprim were
ineffective. Halofuginone and Penta-Sulfa at a high dose had some protective effect. At high doses
Sulfachloropyrazine protected from mortality without affecting the parasitaemia, while Sulfamonomethoxine
suppressed parasitaemia without entirely protecting from mortality. From these data it is concluded that
Halofuginone has a potential as possible chemoprophylactic. While a combination of Sulfamonomethoxine
and Sulfachloropyrazine could be used in the treatment of outbreaks in the field.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
A host-parasite list of the haematozoa of domestic poultry in sub-Saharan Africa and the isolation of Plasmodium durae Herman from turkeys and francolins in South Africa
An annotated host-parasite list of the blood parasites of domestic poultry in sub-Saharan Africa is
presented. This list contains the haematozoa found in domestic waterfowl (ducks, geese and muscovies)
and phasianids (turkey, fowl and peafowl).
In South Africa Plasmodium durae was isolated from 4 out of 8 backyard turkeys, from 3 out of 26
Swainson's francolins and from 1 redwing francolin, but not from 20 helmeted guineafowls and 9
greywing francolins. This points at Swainson's and redwing francolins as being the main natural hosts
of P. durae in South Africa.
The increase in the period of prepatency after intramuscular subinoculation as compared with the
intravenous route was found to correspond to that of a 1 000 fold dilution of an intravenous inoculum of
parasitized blood. This delay was not due to an intervening cycle of exoerythrocytic schizogony, but to
large numbers of the injected erythrocytes apparently not finding their way into the circulation of the
new host.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
Host range, survival in dead hosts, cryopreservation, periodicity and morphology of Plasmodium durae Herman in experimental infections
In experimental infections, fowl , duck, guineafowl and canary were refractory to Plasmodium durae,
which in Japanese quail produced low and transient infections, but a high and long-lasting parasitaemia
in a Lady Amherst pheasant. Heart, blood and brain of dead hosts injected into turkeys, allowed
the recovery and further passaging of the live parasite. This technique could be useful for the recovery
of malaria parasites from suspect postmortem material. Intravenous infection produced parasitaemias
in chicken and turkey embryos, while attempts at allantoic-sac infections of chicken embryos were unsuccessful.
A certain degree of periodicity of schizogony was demonstrated. The South African isolates
of P. durae had smaller schizonts than those described from East and West Africa, with 2-14
merozoites (mostly four) .
Some strains did not produce mature gametocytes in the experimental hosts. Exoerythrocytic schizonts
of P. durae are depicted in this paper for the first time.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
Avian pulmonary hypertension syndrome. IV. Increased right ventricular mass in turkeys experimentally infected with Plasmodium durae
Infection of young turkeys with Plasmodium durae produced a significant increase in the mean relative right ventricular mass from 0,172 in the controls to 0,208 in the infected group. Although turkeys react less strongly to hypoxia than broiler chickens, the similarity of this finding to that previously reported in broilers infected with Aegyptianella pullorum suggests that the hypoxic effect of the anaemia produced by these blood parasites causes the pulmonary hypertension and subsequent right ventricular hypertrophy.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201
Broiler ascites : a review of the ascites work done at the poultry section of the Onderstepoort Veterinary Institute 1981-1990
Broiler ascites, first seen in the form of a high altitude disease, has increased in
importance world-wide in direct proportion to the improvement in growth
performance of modern broilers. At the same time, the incidence has spread
gradually from high altitude (above 2000 m) down to sea level, which gave rise
to proposals of alternative causes including infections, toxins and metabolic
disorders. Our work centred on anatomical and physiological aspects and
included hypoxia models, chemotherapy and selection for genetic resistance. The
latter led to the development of ascites-resistant lines, which allowed resistant stock
to become commercially available in South Africa.
The closure of the Poultry Section of the Onderstepoort Veterinary Institute
brought ongoing ascites research to an abrupt end and some of the completed
work was never published. This review of completed, ongoing and planned
ascites work was at the time compiled as final report to the Director of the
Institute in 1990. It came to light again recently and has been edited for
publication. It also includes a new hypothesis on the reasons for the susceptibility
of the domestic fowl and particularly broilers to hypoxic ascites.http://journals.cambridge.org/WP
Pentastomid parasites of the family Sebekidae Fain, 1961 in West African dwarf crocodiles Osteolaemus tetraspis Cope, 1851 from the Congo, with a description of Alofia parva n. sp
The lungs and viscera of 23 dwarf crocodiles (Osteolaemus tetraspis) obtained from markets in Brazzaville,
were examined for pentastomid infection. Twenty-one animals were infected and harboured a
total of 82 pentastomids, all belonging to the family Sebekidae and representing at least two genera
and three species. Sebekia okavangoensis Riley & Huchzermeyer, was present in the body cavity and
lungs; the other two species were restricted to the lungs. Alofia parva n. sp. (14 female; 10 male) was unusual
in that the fulcrum supporting the anterior hooks carried a cowl-like extension. The remaining species,
provisionally allocated to the genus Sebekia, could not be classified to the generic level with certainty.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
Multifactorial mortality in bongos and other wild ungulates in the north of the Congo Republic
Wildlife mortality involving bongos, Tragelaphus eurycerus, and other
ungulates was investigated in the north of the Congo Republic in 1997.
Four bongos, one forest buffalo, Syncerus caffer nanus, and one domestic
sheep were examined and sampled. Although an outbreak of rinderpest had
been suspected, it was found that the animals, which had been weakened
by an Elaeophora sagitta infection and possibly also by adverse
climatic conditions, had been exsanguinated and driven to exhaustion by
an unusual plague of Stomoxys omega.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.FAO.mn201
A host-parasite catalogue of the haematozoa of the sub-Saharan birds
The prevalence of avian haematozoa in 826 species of birds representing 73 families of sub-Saharan
birds as recorded in the literature or in the files of the International Reference Centre for Avian
Haematozoa and the Veterinary Research Institute is presented. The most commonly occurring blood
parasites were members of the genus Haemoproteus which were represented by 63 species which occurred in 19,1% of the sample. Twenty-five species of Leucocytozoon were recorded in 8,3% of the
birds and represented the second most frequently encountered group of haematozoa. Species of Plasmodium, Trypanosoma, and filarioids (as microfilariae) occurred in 3,5%, 2,5% and 2,8% respectively of the birds sampled; species of Aegyptianella, Atoxoplasma, Babesia and Hepatozoon were infrequently
seen.
An annotated list of the birds examined for haematozoa is presented and brief descriptions of the species of Haemoproteus and Leucocytozoon in birds of the sub-Saharan zone are included.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Foundation for Research Development. Natural Sciences and Engineering Research Council of Canada.mn201
Aerobic intestinal flora of wild-caught African dwarf crocodiles Osteolaemus tetraspis
Intestinal contents were collected from wild-caught African dwarf crocodiles (Osteolaemus tetraspis)
in 1993 and 1995 which were slaughtered at urban markets in the Congo Republic. The samples were
kept frozen and brought back to Onderstepoort for aerobic culture. Out of 29 specimens, 33 species
of bacteria and 20 species of fungi were isolated. The bacteria included three isolates of Salmonella
and eight isolates of Escherichia coli, most of the latter being rough strains. The flora of individual
specimens contained 1-5 bacterial and 0-5 fungal species. Neither Aeromonas hydrophila nor
Edwardsiella tarda were isolated from any of the samples.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
Broiler pulmonary hypertension syndrome. III. Commercial broiler strains differ in their susceptibility
Broilers of 4 different commercial strains were kept during winter at an altitude of 1 350m. The birds were slaughtered at weekly intervals and their relative right ventricular mass (pulmonary arterial pressure index = API values) determined. In addition, the incidence of ascites was recorded. Two of the strains suffered high losses from ascites, while the other 2 showed a certain degree of resistance. The former 2 groups had a higher mean API and a greater percentage of high API values in clinically normal birds than the other 2 groups. The group with the lowest incidence of ascites achieved the highest mean live mass at 51 days. There was also a decrease in mean API with age in clinically normal birds. There was no difference in the incidence of ascites between males and females.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu201