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1.
Vaccination-challenge experiments were conducted in colostrum-deprived calves to evaluate the efficacy of Pasteurella bacterins and vaccines against experimental pneumonic pasteurellosis. Calves were vaccinated with formalin-killed bacterins and live vaccines, then challenge exposed intratracheally with P. haemolytica or P. multocida. Infectious bovine rhinotracheitis virus was inoculated intranasally three to four days prior to P. haemolytica challenge-exposure. All calves were examined for macroscopic and microscopic lesions after being found dead or following euthanasia four to seven days after challenge exposure with the bacterial pathogen. Clinical, hematological, and pathological responses to challenge exposure in aluminum hydroxide absorbed P. haemolytica and P. multocida bacterin-treated calves were consistent with the pneumonic lesions of pulmonary pasteurellosis in the control calves. An oil-adjuvanted P. haemolytica bacterin limited clinical and pathological responses in the affected calves whereas a P. multocida oil-adjuvanted bacterin did not. Both clinical and pathological responses to challenge exposure in calves vaccinated with live Pasteurella vaccines were less severe than those of the control calves. Vaccine effectiveness appeared to be dose dependent.  相似文献   

2.
Twelve Pasteurella-free Holstein-Friesian calves were used in a study to test the efficacy of a live streptomycin-dependent Pasteurella multocida A:3 and streptomycin-dependent Pasteurella haemolytica A1 vaccine. The calves were inoculated intramuscularly twice at 14-day intervals with either the streptomycin-dependent vaccine, containing 1 X 10(6) colony forming units/mL P. multocida and 4 X 10(8) colony forming units/mL P. haemolytica, commercial bacterin, or phosphate buffered saline. Two weeks following the second vaccination, all calves were challenged by intranasal inoculation of 10(8) TCID50/4.0 mL infectious bovine rhinotracheitis virus followed three days later by intratracheal injection with 2.3 X 10(7) colony forming units/mL of a 16 hour culture of P. multocida A:3 and 2.6 X 10(8) colony forming units/mL of an 8 hour culture of P. haemolytica A1. Seven days after challenge with Pasteurella, calves were killed for collection of tissues at necropsy. Each calf was given a score based on macroscopic and microscopic lesions. The scores for the calves receiving live vaccines were significantly lower (p less than 0.025) than those for the controls. Also, the calves receiving live vaccines had a significant (p less than 0.05) increase in the level of serum antibody to P. haemolytica. The results of this preliminary study showed that the streptomycin-dependent vaccine offered better protection than the commercial bacterin against a virulent homologous challenge.  相似文献   

3.
The effectiveness of an oil adjuvant vaccine (OAV) incorporating locally isolated strains of Pasteurella haemolytica type 7 and Pasteurella multocida types A and D was compared with that of Carovax (Wellcome Laboratories) in imported cross-bred lambs. The criterion of efficacy was the ability of the vaccines to reduce the extent of pneumonic lesions in vaccinated as against unvaccinated control lambs. The OAV produced at this Institute significantly reduced the lung lesions at P less than 0.05 level compared with its control group when challenged with P. haemolytica alone. However, the vaccine was unsatisfactory against P. multocida or combined P. multocida P. haemolytica challenge. Carovax did not produce any significant reduction in the lung lesions caused by P. haemolytica and/or P. multocida.  相似文献   

4.
The results of antimicrobial susceptibility testing on 262 strains of Pasteurella multocida and 141 strains of Pasteurella haemolytica isolated from cattle and swine from 1971 to 1974 were analyzed for patterns of resistance to streptomycin, penicillin, tetracycline, and chloramphenicol, using a modified Kirby-Bauer procedure. Resistance was recorded for 80.5% of the isolants of P multocida and 92.2% of those of P haemolytica. Resistance to streptomycin was most frequent, followed by resistance to penicillin and tetracycline. Most cultures of P multocida and P haemolytica were susceptible to chloramphenicol. There were 9 patterns of resistance with the aforementioned antibiotics. The combinations, streptomycin and penicillin and streptomycin and tetracycline, each accounted for approximately 10% of the resistance patterns of P multocida. Approximately half of the 14 isolants of P haemolytica were resistant to the combination of streptomycin, penicillin, and tetracycline. These observations underscore the need for antimicrobial susceptibility testing of clinical isolants of P multocida and P haemolytica.  相似文献   

5.
Seventeen Holstein-Friesian calves weighing an average of 139.8 +/- 13.5 (mean +/- standard deviation) kg were used in a study to determine the efficacy of a live vaccine containing of Pasteurella multocida A:3 and Pasteurella haemolytica A:1. Eleven calves received the vaccine by intramuscular injection in the right shoulder, whereas six calves received vaccine diluent and served as non-vaccinated controls. Fourteen days following vaccination (Day 15) all calves were inoculated deep intranasally with 3.6 X 10(7) TCID50 bovine herpes virus-1. On Day 16, calves were stressed by transports, and on Day 17 calves were challenged intratracheally with P. multocida A:3. On Day 22 calves were euthanized and necropsied, and tissues were collected for pathological and microbiological evaluations. Scores were assigned to each calf based on the severity of observed clinical signs. Macroscopic lung lesions were expressed as percentage of tissue involved relative to the total lung tissue of a calf. Plasma fibrinogen concentration, rectal temperature, serum antibody level, microscopic appearance of lung, and microbiologic results were also recorded for analyses. The control calves had significantly higher clinical-sign scores (P less than 0.05) and more severe gross lesions (P less than 0.05) than the vaccinated calves. Although the vaccinated calves had a slight increase of immunoglobulins M and G classes, the differences were not statistically significant (P greater than 0.05, P greater than 0.05). The results of the study indicate that the live Pasteurella vaccine is effective against experimental P. multocida infection in calves.  相似文献   

6.
Five experiments were conducted that compared aerosol immunization of calves with live Pasteurella haemolytica from logarithmic (6 hour) or stationary (20 to 22 hour) phase cultures. Calves were challenge exposed by transthoracic injection with P haemolytica. In 4 experiments, calves inoculated with 6-hour cultures had slightly lower mean lesion scores (indicating greater resistance to challenge exposure) than those inoculated with 20- to 22-hour cultures. High antibody titers, as detected by a quantitative fluorometric immunoassay or the indirect hemagglutination test, correlated directly with lung resistance (based on lesion scores) regardless of the age of the culture used as the immunogen.  相似文献   

7.
Mild clinical disease was produced in conventionally reared calves by the intranasal inoculation of 18-hour cultures of Pasteurella haemolytica simultaneously with Mycoplasma bovis; at necropsy seven days later moderate pneumonic consolidation was observed in two of four calves. Additional intratracheal injection of these organisms did not increase the severity of disease. In contrast, inoculation of six-hour cultures of P haemolytica with M bovis produced more severe disease and more extensive pneumonic consolidation. The most severe disease and greatest degree of pneumonic consolidation was induced by intranasal and intratracheal inoculation of six-hour cultures of P haemolytica one day after the intranasal inoculation of M bovis. Omitting the intranasal injection of P haemolytica reduced the severity and consolidation only slightly. Studies in gnotobiotic calves revealed that more severe disease and more extensive pneumonic consolidation resulted when M bovis was inoculated before P haemolytic rather than vice versa.  相似文献   

8.
A luminol-dependent chemiluminescence (LDCL) assay was used to evaluate the response of bovine polymorphonuclear leukocytes; (neutrophils [PMN]) to living and heat-killed Escherichia coli, Pasteurella multocida (type A, serotype 3), and P haemolytica (biotype A, serotype 1), and to heat-killed P haemolytica and sterile culture supernatant from living P haemolytica. Control cultures containing PMN that had not been phagocytically stimulated with bacteria had a modest increase in LDCL during the initial 10 minutes of incubation, followed by a gradual decline throughout the 120-minute incubation period. Bovine PMN emitted LDCL more efficiently when the cells were exposed to living E coli or P multocida than when they were exposed to the same bacteria killed by heat. The mean LDCL values for reaction mixtures containing living E coli or P multocida peaked at 30 minutes of incubation and remained above values for mixtures containing the same heat-killed bacteria. Kinetics of the LDCL response of bovine PMN to heat-killed P haemolytica were similar (although reduced in amplitude) to that observed with killed E coli or P multocida. The LDCL response of bovine PMN to living P haemolytica was not like that for E coli or P multocida, and was characterized by the development of a peak response at 10 minutes followed by a precipitous decrease in responsiveness and a subsequent complete cessation of LDCL. Addition of sterile culture supernatant from living P haemolytica to test samples containing heat-killed P haemolytica induced a response similar to that obtained with the living microorganism.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

9.
The present study was aimed at elucidating the role of heterophil granulocytes during the initial infection with Pasteurella multocida subsp. multocida in chickens. Chickens (17 and 19 wk old) were depleted of their heterophil granulocytes by 5-fluorouracil treatment. When the heterophil blood counts were significantly reduced, the birds were inoculated intratracheally with 1.8-4.3 x 10(4) colony-forming units of P. multocida. Twelve, 24, or 48 hr postinoculation, the birds were euthanatized and examined for macroscopic and histologic lesions in the lungs. Bacterial invasion was determined by culture of P. multocida from the spleen. Recruitment of heterophils into the respiratory tract during infection was found to contribute considerably to the lung lesions in chickens and was found to mediate tissue damage, possibly allowing a more rapid systemic spread of P. multocida. However, during progression of the infection, the heterophil-mediated necrosis in chickens seemed to stimulate giant cell demarcation of infected lung tissue, which coincided with the clearance of P. multocida from the spleen, thus hampering further invasion. Consequently, heterophil activation plays a dual role for the outcome of a P. multocida infection in chickens, where it initially seems to promote invasion and systemic spread but subsequently helps limit the infection by giant cell formation and bacterial clearance.  相似文献   

10.
Pasteurella multocida was isolated from the lungs of calves that died on a farm in the south of England. This organism was inoculated experimentally into 13 calves by the intratracheal route: in all but two of the calves mild clinical disease resulted and at necropsy, three or four days later, pneumonic consolidation involving up to 22 per cent of the lung was observed. P multocida was isolated from all but two of the lungs. Of two calves inoculated intravenously with P multocida, one showed mild clinical disease and slight pneumonic consolidation at necropsy and the other remained normal. Control calves inoculated intratracheally and intravenously with sterile broth showed no signs of illness and no pneumonic consolidation. Histologically the lung lesions comprised a fibrinous bronchopneumonia with variable sized areas of coagulative necrosis, extensive deposition of fibrin and massive dilatation and oedema of the interlobular and pleural lymphatics. It is concluded that P multocida should receive more recognition as a primary pathogen.  相似文献   

11.
A survey of antibody to Pasteurella haemolytica and P multocida, using a fluorometric immunoassay, was conducted on sera collected from 264 dairy cattle from 3 herds. Serum antibody titers to P haemolytica were 0 to 270 with low titers (less than 25) seen in 48.1% of the cows and heifers. Serum antibody titers to P multocida were 0 to 380 and the frequency of distribution of these titers were more even than for P haemolytica. Mean serum antibody titers to P haemolytica were significantly (P less than 0.005) higher in cattle from an open dairy herd when compared with those from 2 closed herds. Antibody titers to these organisms was determined in 7 colostrum samples. Pasteurella haemolytica antibody titers varied, depending on the whey separation technique used. Passive transfer of colostrum-derived antibody in 5 neonatal calves resulted in a maximum mean serum antibody titer at 20 hours after birth for P haemolytica and at 8 hours after birth for P multocida. Serum titers were higher overall for P multocida than for P haemolytica. Serum titers for P haemolytica declined rapidly. A significant (P less than 0.05) increase in antibody to P multocida was observed at 5 days of age.  相似文献   

12.
Four male dairy calves, ages 1-9 months, were inoculated intratracheally (IT), with log dilutions (1.5 X 10(3)-1.5 X 10(6)) of an isolate of P. haemolytica A-1. Doses of bacteria varied according to ages of the calves, older calves receiving the larger doses. All four calves became severely ill within 24 h after inoculation and antibiotic treatment was considered essential. Two months later the four calves remained healthy after IT injection of P. haemolytica, again given in log dilution (2.8 X 10(2)-2.8 X 10(5)). The control calf, given a dilution of only 28 viable P. haemolytica (plate count), developed severe respiratory infection 9 days post inoculation. Antibiotic treatment was given to this calf for 7 days, at which time recovery was evident. All five calves developed direct bacterial agglutination titers to P. haemolytica. Persistent leukocyte migration inhibition indexes of all calves were decreased by greater than or equal to 20% compared to their controls. Although the initial doses administered were low, the calves became ill. Most reports refer to massive doses necessary to produce primary disease and significant agglutination titers.  相似文献   

13.
Pneumonic lesions in calves were induced with Pasteurella haemolytica or P multocida. The inoculum, consisting of a suspension of either organism, was administered by transthoracic intrapulmonic injection to 23 calves. Three died of septicemia; the 20 remaining, killed 96 hours after inoculation, had an expanding unifocal pneumonia qualitatively comparable with that of acute pneumonic pasteurellosis (shipping fever). The concentration of bacteria that consistently produced a lesion was a 5-ml volume containing 10(9) colony-forming units of bacteria; a concentration of 10(6) colony-forming units inconsistently produced lesions. Bacteria, except in calves that developed septicemia and died, remained localized at the injection site. The inflammatory process spread within the lungs, not only through airways, but through the interlobular and interalveolar septa as well.  相似文献   

14.
An experiment was designed to study the in vivo effect of Pasteurella haemolytica A2 infection on the phagocytosis activity of caprine broncho-alveolar macrophages and the extent of pneumonic lesions. Twelve healthy local Kacang goats, about 7 months of age, were divided into two groups of six. Goats in group 1 were inoculated intratracheally with 4 ml inoculum containing 2.8 x 10(9) colony-forming units (CFU)/ml of Staphylococcus aureus. Goats in group 2 were inoculated intratracheally with 4 ml of inoculum containing 9.5 x 10(8) CFU/ml of Pasteurella haemolytica A2 isolated earlier from pneumonic lungs of goat. At intervals of 3 and 7 days post-challenge five goats from each group were killed and the lungs were washed with sterile phosphate-buffered saline. Smears were prepared from the lung washing fluid and the number of macrophages with phagocytic activity was determined. At day 3 post-infection, goats of both groups showed a similar pattern of pneumonic lesion. The lung washing fluid of goats in group 2 was found to contain numerous neutrophils and macrophages. Goats in group 2 showed significantly (P < 0.05) higher extent of lung lesions than group 1. Similarly, the average extent of lung lesions was significantly (P < 0.05) more severe in group 2 at day 7 post-infection. The lung washing fluid contained mostly macrophages. The phagocytic activity following S. aureus infection was more efficient and significantly (P < 0.01) higher compared with infection by P. haemolytica A2. There were weak correlations between the extent of pneumonic lesion and the phagocytic activity. Thus, goats with poor phagocytic activity were likely to develop more extensive lung lesions.  相似文献   

15.
In three experiments subcutaneous vaccination of calves with adjuvanted bacteria-free leukotoxic culture supernatant from log phase cultures of Pasteurella haemolytica A1 (toxin 1) was shown to induce some protection against intrabronchial challenge with live P. haemolytica A1. This toxin 1 vaccine was as effective as a whole cell bacterin in stimulating agglutinating antibody to P. haemolytica. Induction of leukotoxin neutralizing activity was variable; in some cases vaccination only primed the animal to produce an anamnestic response after challenge, whereas in other instances antitoxic activity increased in response to immunization. Two doses of vaccine were shown to be more effective than a single immunization. Vaccination with leukotoxic culture supernatant from the nonpathogenic P. haemolytica serotype 11 was as effective as vaccination with toxin 1 in stimulating antitoxic activity but was not protective. This implies that both serospecific agglutinating activity and an antitoxic response are needed for immunity.  相似文献   

16.
A group of Caesarian-derived, colostrum-deprived lambs was inoculated intranasally and intratracheally with a virulent Mycoplasma ovipneumoniae isolate selected from ovine mammary studies and propagated in an ovine mammary gland. Other groups of lambs were inoculated with M. ovipneumoniae in combination with Pasteurella haemolytica type Al or P. haemolytica alone. The M. ovipneumoniae isolate alone did not induce any specific pneumonic lesions in the lambs and when combined with P. haemolytica type Al did not increase the severity of the P. haemolytica-type lesions. Fifty percent of lambs inoculated with P. haemolytica developed a purulent and exudative bronchopneumonia with pleurisy and high titres of P. haemolytica were recovered from these lesions.  相似文献   

17.
Pasteurella multocida, serovar A: 3, selected by pathogenicity in mice from among 10 strains isolated from pneumonic lesions of calves, was adjusted to 10(7), 10(8) and 10(10) colony-forming units (CFU), and inoculated intratracheally into four calves. All calves showed pyrexia and had lungs with congestion and hepatization. Inoculation with 10(10) CFU of bacteria produced respiratory symptoms and abscesses in lungs. This information will aid elucidation of the pathogenicity of P. multocida and the development of vaccines.  相似文献   

18.
Calves immunised with different Pasteurella antigens (inactivated whole cells, sodium chloride extract) where challenged two weeks after the second immunization with the homologous strain. The intracutaneous application of whole cells of P. haemolytica A1 and P. multocida A was effective. The incidence of pneumonia was reduced and the pneumonic lesions were less severe. The sodium chloride extract was not effective.  相似文献   

19.
The role of neutrophils in the development of peracute lung lesions of bovine pneumonic pasteurellosis was investigated. Eight calves were divided into two groups of four calves each. Group I was treated with intravenous phosphate-buffered saline and served as the neutrophil sufficient calves. Group II was treated with intravenous hydroxyurea which produced a state of neutropenia. When peripheral blood neutrophil numbers dropped below 300 cells/microL in group II, all calves were challenged with an intrabronchial bolus of Pasteurella haemolytica in the log phase of growth. An acute inflammatory process occurred in both groups of calves indicated by a rise in body temperature. While pulmonary lesions occurred in both groups by six hours postinoculation, they varied in pathological characteristics. Pulmonary lesions in the neutrophil sufficient calves consisted of fibrinopurulent alveolitis-bronchiolitis with associated alveolar septal necrosis, interlobular edema, and intravascular thrombi. The neutrophil deficient calves had extensive intra-alveolar edema, interlobular edema, intraalveolar hemorrhage, atelectasis, and focal areas of alveolar septal necrosis. These results show that P. haemolytica can induce severe pulmonary tissue damage through both neutrophil dependent and neutrophil independent mechanisms.  相似文献   

20.
A model for the induction of pneumonia caused by Pasteurella multocida type-A was developed. Anesthetized pigs were dosed intratracheally with 10(10) colony forming units of P. multocida type-A suspended in a total dose of saline based on the pig's body weight (8 mL/kg). A severe bronchopneumonia was present when the treated pigs were euthanized seven days postinfection. The mean percentage of pneumonic lesions in the treated pigs, as determined by morphometric measurement, was 14.03 +/- 7.01 (X +/- SD). In contrast, in the control pigs, the mean percentage of pneumonic lesions was 0.59 +/- 0.52. For the treated pigs during the period following induction of pneumonia, weight gain and feed intake were reduced significantly (p less than 0.05) compared to the controls. It was shown that severe pneumonia could be induced without the use of other infectious agents, which could potentially confound the experimental model.  相似文献   

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