共查询到20条相似文献，搜索用时 46 毫秒
1.
During 1970, 93 abomasa from cattle in Ontario were examined, and from 63 of these abomasa nematode species of the genera Ostertagia, Haemonchus and/or Trichostrongylus axei were recovered. The abomasa were from cattle six months to two years of age and were collected either from the postmortem room at the Ontario Veterinary College or from two abattoirs near Guelph. The numbers of worms per abomasum were estimated and their genera were identified from a one-twentieth volume of the washings and contents. The prevalence of Ostertagia species was estimated by examining random samples of adult male worms. Morphological variations in the species of the genera Ostertagia and Haemonchus were estimated by examining random samples of adult females. The predominant nematode was Ostertagia ostertagi. Other Ostertagia species recovered were O. trifurcata, O. lyrata and O. circumcincta. The numbers of nematodes recovered were generally low. Adult Ostertagia females had well-developed vulvar flaps. However, in abomasa where adult male O. trifurcata and O. lyrata were found, some adult female Ostertagia worms had reduced or no vulvar flaps. In two abomasa, adult Haemonchus females had large pendulous or “linguiform” vulvar flaps, and adult males had mean spicule lengths of 517 and 512 μ and were, therefore, unlike any of the recognized Haemonchus species. 相似文献
2.
A total of 959 faecal samples were obtained from dogs in 12 native communities in Northern Saskatchewan, Central and Northern Alberta and the Northwest Territories. All samples were examined using a flotation technique. Samples from an area of endemic human amoebic infections were also examined by a formol-ether sedimentation method. Eighteen necropsies were performed. Entamoeba histolytica cysts were recovered from dog faeces at Loon Lake, Saskatchewan. Toxocara canis had low incidence in Saskatchewan and Central Alberta, and appeared to be almost non-existent further North. Toxascaris leonina was found in all areas surveyed. Canine hookworm infections were plentiful in all areas, the highest incidence being recorded from Northern Alberta and Northwest Territories. Many Taenia (or Echinococcus) infections were found consistently in all areas. Only one infection with Dipylidium caninum was discovered. Metorchis conjunctus infections were found to be common in the Saskatchewan reserves. Infections with Diphyllobothrium sp. were found in all communities with access to good fishing. One specimen of Dioctophyma renale was recovered at necropsy. Infections with parasites of no known zoonotic importance such as Trichuris, Alaria and Isospora species were also recorded. 相似文献
3.
A brain heart infusion agar supplemented with 16.7% rabbit serum (BHIR) was found the most suitable for the culturing of ruminant mycoplasma. Gourlay medium and Perreau medium (4, 5) were not suitable for growth of Mycoplasma mycoides var. mycoides or M. agalactiae, but were satisfactory for M. mycoides var. capri.Four strains of M. mycoides var. mycoides, three strains of M. agalactiae and three strains of M. mycoides var. capri were grown in our laboratory. 相似文献
4.
Using a modified aerosol generator, white mice and calves were exposed to aerosols of viable Staphylococcus aureus and Pasteurella haemolytica and the clearance of the inhaled organisms by the lungs of the experimental animals was measured. Fifty-seven percent of inhaled S. aureus were cleared in two hours by the mouse lungs, 79% were cleared in four hours and 93% were cleared in eight hours. Fifty-six percent of inhaled P. haemolytica were cleared in two hours by the mouse lungs, 76% were cleared in four hours and 93% were cleared in eight hours. Seventy percent of inhaled S. aureus were cleared in two hours by the calf lungs, 90% were cleared in four hours and 95% were cleared in eight hours. Seventy-five percent of inhaled P.haemolytica were cleared in two hours by the calf lungs, 90% were cleared in four hours and 92% were cleared in eight hours. 相似文献
5.
In rats, rabbits, sheep, and goats experimentally infected with several strains of Trypanosoma brucei, the trypanosomes were observed to localise extravascularly in connective tissues. Focal inflammatory reactions were associated with the localisation of the parasites. Trypanosoma congolense in the same species of animals and T. vivax in sheep and goats, were not observed to localise outside blood vessels. On the basis of these observations it appears that the pathogenesis of the disease caused by T. brucei differs from that caused by T. congolense and T. vivax. 相似文献
6.
Nematode populations is stabled ewes of the Rimouski region were studied by means of fecal worm egg counts, fecal culture of larvae, and worm counts at necropsy. It was found that during the winter strongyle egg counts were low, Trichostrongylus eggs being most numerous, The stronglye egg counts increased following lambing and reached peak in June. Ostertagia spp was the principal contributor to this “spring-rise”, with substantial contribution from Trichostrongylus and Haemonchus contortus. The bulk of adult worm populations in winter, however, was made up of Trichostrongylus, whereas the great majority of the populations of Ostertagia spp, H. contortus and Nematodirus spp were inhibited in development at the fourth larval stage. All the worms recovered at necropsy in spring were adults, coinciding with the “spring-rise”. 相似文献
7.
Experiments were conducted to compare the efficacy of several media to isolate Br. abortus, Br. suis, and Br. melitensis from infected animal tissues. Greater differences among media were observed when infected tissues were the source of organisms than when in vitro propagated strains were used. All basal, enriched, and selective media used were adequate for isolation in most instances. However, enrichment of media with serum was necessary for maximum isolation of all strains of Brucella. Due to Brucella species and strain differences, employment of more than one medium was advantageous. 相似文献
8.
Thirty cases of respiratory infections in adult dogs were treated with colistimethate sodium. E. coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Paracolobactrum sp., and Aerobacter aerogenes responded to therapy, whereas Proteus sp., Streptococcus faecalis, Streptococcus pyogenes, and Staphylococcus aureus were resistant to treatment. 相似文献
9.
Saskatchewan, in the summer of 1962, was the scene of an extensive outbreak of western equine encephalomyelitis (WEE) in horses. The results of mosquito survey work showed Culiseta inornata and Culex tarsalis respectively to be the two most abundant mosquito species during midsummer. These species are those reported to be most commonly associated with outbreaks of WEE. Five hundred and sixty-four pools of mosquitoes were examined for the presence of WEE virus. Six pools, three of C. tarsalis and one each of C. inornata, Aedes flavescens and Aedes dorsalis, yielded WEE virus. Positive mosquitoes were from St. Walburg (C. inornata), Saskatoon (C. tarsalis — two, A. dorsalis — one), Outlook (C. tarsalis) and Kisbey (A. flavescens). 相似文献
10.
Studies on the site of proliferation of Pasteurella haemolytica in the bovine nasal cavity have been carried out. P.haemolytica were isolated from 15 selected major anatomical areas of the nasal cavity in calves with high numbers of P.haemolytica following shipment from Western Canada. When the organisms were present in the nasal cavity of live animals in low numbers, they were isolated from many, but not all, areas. P.haemolytica was isolated post mortem from one or more selected areas of several nasal cavities in spite of negative antemortem cultures. By the direct fluorescent antibody technique, P.haemolytica was demonstrated at the surface of nasal epithelial cells. Organisms were not seen in or between epithelial cells nor in the ducts nor alveoli of glands. The findings were similar when high and low numbers of P.haemolytica were present in the nasal cavity. 相似文献
11.
Four Salmonella strains were used. With two, S. canada and S. enteritidis, establishment of infection in pigs was poor. Although improved establishment was achieved with two strains of S. typhimurium, no infections were extensive. No significant difference was detected between excretion of infecting strains by pigs receiving chlortetracycline at levels of ten gm per ton of feed and that by control counterparts. Comparable establishment of S. typhimurium S192 was achieved in pigs receiving 20 or 40 gm of chlortetracycline per ton. Resistant variants were isolated from some animals in all experiments using S. typhimurium S192. Almost without exception such variants were isolated only after specimen enrichment. The numbers of specimens from test animals yielding resistant variants were more than twice those of control counterparts. Numbers of such variants in material from the former were much greater. In vitro transfer of resistance to S. typhimurium S192 was demonstrated both in waters from drinking troughs and during specimen enrichment. The former, indicating the risk of transfer in pigs' environments and packing houses, has disturbing implications for public health. The latter emphasizes the difficulties of determining antibiotic sensitivity of pathogens as they occur in the animal body. 相似文献
12.
Fortnightly treatment of susceptible calves with 1-tetramisole during the first two months of continuous exposure to pastures residually heavily-infected with Ostertagia ostertagi, Cooperia oncophora and Nematodirus helvetianus did not prevent the development of clinical parasitic gastroenteritis, although the infections were not as severe as in nontreated calves. Development of resistance in treated calves was manifested by significantly smaller numbers of Cooperia eggs in utero (which were reflected by reduced fecal egg counts) and by significantly smaller Nematodirus worm burdens than in susceptible calves that commenced grazing coincident with cessation of treatment. The findings also indicated that resistance to Nematodirus helvetianus was slower in developing in treated than in nontreated infected calves. 相似文献
13.
Kids, 6-28 weeks of age, infected with 200-1000 infective larvae of meningeal worm ( Pneumostrongylus tenuis) of white-tailed deer (Odocoileus virginianus), developed colitis and peritonitis. Bacteroides sp., Bacillus sp., Escherichia coli, Proteus sp. and Enterococcus sp. were found in the peritoneal cavity. Most kids were moribund or dead 4-11 days after infection and frequently the colon had ruptured. Only two kids (of 11) in which the disease was allowed to run its course survived colitis and peritonitis but these two animals developed severe neurologic signs 18 and 38 days after infection. Numerous developing worms and various traumatic and other lesions were found in the central nervous system of kids which developed neurologic signs. 相似文献
14.
A complement-fixation (CF) antigen which has been prepared from Theileria infected erythrocytes is capable of reacting to specific serum antibodies of deer acutely infected with Theileria.No sera from 17 deer known to be free of Theileria infection reacted positively to the CF test. Of 35 tests on sera from 12 infected deer having a parasitemia of 2% or less and no accompanying anemia, only 10 (29%) were positive, 2 (6%) were suspicious, and 23 (66%) were negative. Of 65 tests on 8 acutely infected deer, 49 (75%) were positive, 4 (6%) were suspicious and 12 (18%) were negative. Of the 8 deer in which acute theileriasis occurred all reacted to Theileria antigen at one time or another. A significant correlation was found between CF titers and the degree of parasitemia in acute infections. Rabbits were hyperimmunized using erythrocytes from either normal or Theileria infected deer. Reciprocal absorption of the hyperimmune sera with Theileria and normal erythrocytic antigens demonstrated the presence of antibodies specific for Theileria. 相似文献
15.
Four month-old foals were infected orally with 75 mL of a suspension of 5.0 × 10 8 Corynebacterium equi per mL. Two foals were killed after ten days and had scanty number of C. equi in the caeco-colic lymph nodes. No C. equi were recovered from the other two foals, killed 20 days after infection. No gross pathological change was detected in these four foals, although mild microscopic lesions were seen in the ileum of one foal. Results of lymphocyte blastogenesis using peripheral blood lymphocytes and C. equi antigens showed, however, that lymphocytes became sensitized to C. equi following this challenge. In a second experiment four month-old foals were given orally the same dose of organisms but on five consecutive days. Two foals were killed ten days after infection and showed mild histological changes in the large bowel mucosa and C. equi could be recovered from all intestinal lymph nodes cultured. In one of these foals moderate numbers of C. equi were present in the bronchial lymph node. Of the other two foals, one died after 22 days with severe ulcerative enterocolitis and intestinal lymphadenitis. Only one small pulmonary abscess was detected despite large numbers of C. equi in the lungs. The other foal developed similar intestinal changes and was euthanized 25 days after infection. No C. equi were detected in the lungs or bronchial lymph node. Lymphocyte blastogenesis in these animals showed a rapid rise in response to C. equi antigens. These studies suggest that C. equi pneumonia in foals does not always arise from an intestinal infection, that minor intestinal infection causes a cellular immune response and that massive exposure of the bowel over a sustained period is necessary to induce intestinal lesions. 相似文献
16.
Gross changes in the lungs of Ascaris suum- infected calves consisted of atelectasis and hemorrhagic foci, edema and emphysema, frequently with bullae. Prominent microscopic lung lesions were edema and emphysema of the interlobular septa with large numbers of eosinophils within and around lymphatics, peribronchiolar lymphoid nodules and parasitic granulomas. Many of the microscopic features were consistent with those found in atypical interstitial pneumonia. Changes in the alveoli were atelectasis, the exudation of plasma proteins, mononuclear cells and eosinophils, and alveolar wall thickening. Lesions found later included fibrosis and fetalization of the alveolar walls. Plasma cells and neutrophils were not common. Challenge with Toxocara canis after sensitization with A. suum resulted in the lungs developing a few areas of atelectasis. Migration of T. canis to lungs of calves is slower than A. suum. A. suum larvae were always found in bronchi, bronchioles and alveoli of calves that died. Lesions were observed in the liver but not the kidney of A. suum infected calves; both lung and liver lesions tended to resolve with time. 相似文献
17.
Bacteriological examination of faeces and swabs from fourteen species of reptiles predominantly constrictors, yielded six serotypes of Salmonella as well as Arizona hinshawii, Proteus species, Citrobacter freundii and Enterobacter species. Organisms isolated were identified using conventional bacteriological methods and yielded two serotypes of salmonellae not previously identified in Canada: Salmonella nima and Salmonella 58:a. 相似文献
18.
Strains of hemolytic E. coli are implicated in edema disease and enteritis of swine. Immunological experiments were conducted to determine the specific role played by hemolytic E. coli in the etiology of these diseases. When cell-free extracts prepared from a frequently isolated E. coli — 0139:K82(B) were injected 48 hours apart into a healthy pig, symptoms of edema disease were produced on both occasions. Similar symptoms were produced when this extract was injected into a colostrum-deprived pig raised in isolation. The Schultz-Dale reaction revealed no difference between the contractions of the ilea of sensitized and non-sensitized guinea-pigs. In vitro treatment of a single non-sensitized guinea-pig uterus with extracts of five different strains of hemolytic E. coli produced sharp contractions in every trial. A similar treatment with extracts of four non-hemolytic E. coli strains also stimulated the non-sensitized guinea-pig uterus but the magnitude of the contractions was much less. These studies indicated that the cell-free extracts of hemolytic E. coli produced a marked nonspecific toxic reaction. 相似文献
19.
Strains of enterobacteria (nine Escherichia coli and two Salmonella) isolated from primary or secondary infections in the dog, cat, pig, calf and kangaroo were studied for the presence of extrachromosomal drug resistance factors (R factors). Seven strains of E. coli and two strains of Salmonella transferred resistance involving the following antibiotics: streptomycin, ampicillin, chloramphenicol, neomycin and tetracycline. All strains harboring R factors transferred streptomycin resistance and the identified resistance patterns were as follows: Sm Am, Sm Te, Sm Neo, Sm Am Te, Sm CI Neo and Sm Am CI Te. The levels of resistance observed were comparable for all donor strains and their converted recipients. Strains of E. coli harboring R factors were isolated from three dogs that had died of either otitis (followed by a generalized infection), enteritis or bronchopneumonia — secondary to distemper. The bacteria isolated from cats were recovered at the necropsy of animals that had died of purulent pleuresy and feline panleukopenia. The other strains (two Salmonella and one E. coli were isolated from fatal enteric diseases in the pig, calf and kangaroo. 相似文献
20.
Twenty-nine caesarian derived colostrum deprived germfree pigs were reared in isolators in groups of three to four per isolator. At seven days of age each group was inoculated intranasally with one of four strains of Bordetella bronchiseptica (designated B, J, L and 55B), or Pseudomonas aeruginosa or a mucoid strain of Escherichia coli, all previously isolated from nasal mucus of pigs affected with clinical atrophic rhinitis. Another group was inoculated simultaneously with B. bronchiseptica B and Pasteurella multocida. The animals were observed for clinical signs of atrophic rhinitis and monitored bacteriologically at weekly intervals for seven weeks. Then they were bled for serology and killed and their respiratory organs examined for gross and histopathological lesions. All of the pigs inoculated with the Bordetellae had inflammation of the nasal mucosa and developed positive serum antibody titers against all four of the Bordetella strains used in this study. Strain J caused sneezing and turbinate atrophy in three of four pigs. One of the three pigs inoculated with strain L died in ten days from bronchopneumonia and pericarditis and had turbinate atrophy. Strains B and B55 caused no turbinate atrophy, but two out of three pigs inoculated with both B. bronchiseptica B and P. multocida had turbinate atrophy. No nasal lesions were observed in the pigs inoculated with E. coli or P. aeruginosa or in the noninoculated germfree controls. The results indicate a variation in the ability of different strains of B. bronchiseptica to cause turbinate atrophy in pigs and demonstrate that nasal infections by these organisms stimulate serum antibody response. Presence of P. multocida appears to increase the severity of the lesions. As the E. coli and Pseudomonas failed to produce atrophic rhinitis, they are probably of no significance as primary etiological agents in the atrophic rhinitis syndrome in swine. 相似文献
|
下载免费PDF全文