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1.
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 × 109 colony‐forming units (CFU)/ml of Staphylococcus aureus. Goats in group 2 were inoculated intratracheally with 4 ml of inoculum containing 9.5 × 108 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   

2.
Pneumonia is a leading cause of loss to ruminants throughout the world. Mannheimia (Pasteurella) haemolytica is one of the most important etiological agent of pneumonia in cattle, sheep, and goats. This study was carried out to determine the incidence of M.haemolytica antigens using immunohistochemistry labelling of formalin-fixed, paraffin-embedded tissues in pneumonic lungs of goats slaughtered at abattoir, and then to compare these immunohistochemistry results with the results of bacterial isolation. For these objectives, a total of 1505 goat lungs slaughtered in slaughterhouse were grossly examined and pneumonia was detected in 74 cases (4.91%). Of these, with the exception of verminous pneumonia observed in 32 cases, on 42 pneumonic lungs immunohistochemical examinations were performed. Formalin-fixed and paraffin-embedded lung tissue samples were immunohistochemically stained by the avidin-biotin-peroxidase complex (ABC) procedure using polyclonal antibodies to detect M.haemolytica antigens. Pneumonic lesions were more frequently encountered in cranioventral lobes than caudal lobes, and characterized by irregular lobular foci of atelectasis or lobar pneumonia. The presence of M.haemolytica antigens was detected in 19 (45%) out of 42 pneumonic lungs. Bacterial antigens were found most frequently in the cytoplasm of bronchial and bronchiolar epithelial cells, in the swirling degenerating leukocytes in the alveoli, and in the degenerating leukocytes in the area of coagulation necrosis, less frequently in the epithelial cells of bronchial glands, and lymphoid cells. Conclusionly, immunohistochemical detection of M.haemolytica antigens in pneumonic lungs appear to be more reliable compared to bacterial isolation.  相似文献   

3.
Pasteurella haemolytica leukotoxin is a pore-forming cytolysin which acts as a virulence factor in pasteurellosis of domestic ruminants. Leukocytes from cattle, sheep and goats are susceptible to leukotoxin-induced lysis; however, leukocytes from non-ruminant species so far tested are resistant to leukotoxin-induced lysis. Neutrophils obtained from three white-tailed deer, four Saiga antelope, an Addra gazelle, a Grant's gazelle and a Sable antelope were tested for susceptibility to the lytic effects of P. haemolytica leukotoxin using lactate dehydrogenase release. Results were compared to those obtained using neutrophils from a steer and cultured bovine lymphoma cells. Neutrophils obtained from all these ruminants, except the Addra gazelle, were susceptible to P. haemolytica leukotoxin. Individual variation among the Saiga and the deer did not appear to be due to the percentages of neutrophils or the percentage of contaminating erythrocytes in the cell preparations.  相似文献   

4.
In a field disease outbreak, 60 female goats died over a 2–3 week period. Necropsies of seven of these does revealed that six had an acute exudative necrotising broncho-pneumonia, and moderate to high numbers of Pasteurella haemolytica were isolated from their lungs. Caprine herpesvirus, identified as Bovid herpesvirus type 6, was isolated from the lungs of two of these does, including one with pneumonia, and from nasal swabs of in-contact goats. Clinical disease was only observed in does, and deaths began 3 weeks after the introduction of a mob of goat hoggets from another farm.  相似文献   

5.
Pasteurella haemolytica in the Tracheal Air of Calves   总被引：2，自引：2，他引：0       下载免费PDF全文
Pasteurella haemolytica was shown to be present in the tracheal air of calves and was likely transported in droplet nuclei formed in the nasal passages. The number of colonies of P. haemolytica found in the tracheal air of the calves ranged from 1.9 to 12.5 colonies per cu ft of air. As long as P. haemolytica colonized the nasal passage in numbers detectable in nasal swabs it could be found in the tracheal air but there was no direct correlation between the numbers in the nasal flora and the numbers found in the tracheal air. Of the P. haemolytica which travel via the tracheal air 47.8% were in droplets of the aerodynamic size of from less than one to five microns, the size range which is considered hazardous for lung penetration in man.

The technique used demonstrated the presence of P. haemolytica in the tracheal air of calves and provides a useful tool for monitoring and determining the phase in the colonization of the respiratory tract in which the majority of the potential pathogen P. haemolytica pass from the nose to the tracheal air and presumably to the lung.

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6.
Objective To perform a comprehensive phenotypic characterisation of 35 isolates of bacteria previously identified as haemolytic Pasteurella‐Actinobacillus and obtained from cattle and sheep. Design The 35 isolates that had been obtained from Australian animals, 30 from cattle and five from sheep, were compared with reference strains of the five recognised species of the genus Mannheimia ‐ M haemolytica, M glucosida, M granulomatis, M ruminalis and M varigena. Results Thirty‐four of the isolates could be confidently assigned to three species of the genus Mannheimia. Twenty‐nine were M haemolytica, with 25 being isolated from cattle and four from sheep. All but three of the bovine M haemolytica were isolated from pneumonic lungs. Of the three remaining bovine M haemolytica isolates, one was obtained in pure culture from a bovine milk sample and the other two as part of a mixed flora associated with a middle ear infection of a calf suffering mucosal disease. Of the four ovine M haemolytica isolates, two were isolated in pure culture from milk and two, also in pure culture, from pneumonic lungs. Three bovine isolates were identified as M granulomatis ‐ one from a tongue abscess, one from a jaw abscess and one from a lung showing suppurative bronchopneumonia. Two bovine isolates were identified as M varigena‐ one coming from an udder and the other from a spleen. The available diagnostic records provided no information on whether these isolates were associated with a disease process. The remaining isolate was obtained from an ovine tongue abscess and could not be assigned to a recognised species within the genus Mannheimia. Conclusion The study represents the first time that M haemolytica, M granulomatis and M varigena have been recognised as being present in cattle and sheep in Australia. Veterinary laboratories that encounter Pasteurella‐Actinobacillus‐like organisms from cattle and sheep should attempt as complete a characterisation as possible to help improve our knowledge of the disease potential of these organsims.  相似文献   

7.
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8.
Groups of lambs were either slaughtered at weekly intervals between November and June, or regularly sampled over this period. The number of isolations of Pasteurella haemolytica and Mycoplasma sp. from the lungs increased during the later part of two seasons, as did the incidence of lesions typical of enzootic pneumonia. P. haemolytica was frequently isolated after February from nasal swabs in spite of the presence of serum antibody titres against this organism. Serum antibody titre to two adenoviruses were found to fall to a low level, one in January, the other in May, and then to rise again. Virus isolations were made at the time the homologous antibody titres were lowest.  相似文献   

9.
Coxiella burnetii is a zoonotic pathogen typically associated with clinical and asymptomatic infection in ruminant livestock. A re‐emerging pathogen of significant public health importance, C. burnetii has caused recent epidemics in the United States and Europe, and public livestock exhibitions are increasingly scrutinized as a potential source of C. burnetii exposure. Although C. burnetii prevalence data among North American domestic ruminants are extremely limited, contemporary studies suggest that this pathogen is both geographically widespread and highly prevalent on a herd basis, especially in dairy cattle and goat populations. We utilized a real‐time PCR assay to detect C. burnetii faecal shedding by clinically normal, non‐periparturient beef cattle, meat goats and sheep exhibited at Iowa agricultural fairs. Individual faecal samples were collected from beef cattle, meat goats and sheep exhibited at twelve Iowa county fairs during the summer of 2009. The sample pool was blocked by species and fair, and ten samples from each block were randomly selected for the diagnostic assay; this test pool is considered sufficient to identify with 95% confidence a shedding animal in a population prevalence of 2.85% (cattle and sheep) and 6.25% (goats). Detection of C. burnetii DNA was determined through use of a real‐time PCR assay validated for use in bovine, ovine and caprine faeces; threshold of detection is one DNA copy per PCR (sensitivity 95.8%, specificity 100%). All tested samples were negative for C. burnetii DNA. We conclude that non‐dairy, non‐periparturient ruminants exhibited at Iowa fairs are unlikely to shed C. burnetii in their faeces and that this population should not be considered to be a significant exposure risk to other livestock or fair attendees.  相似文献   

10.
An outbreak of severe respiratory disease in a goat herd was associated with Mycoplasma ovipneumoniae, Mycoplasma arginini, Mannheimia haemolytica and Pasteurella multocida with mortality rates exceeding 20% in kids. Post mortem features in affected kids included severe pleuropneumonia, lung consolidation, large quantities of pleural fluid and pericarditis. This is the first report of atypical proliferative pneumonia in goats in Portugal.  相似文献   

11.
Nigerian strain of Peste des Petit Ruminant (PPR) virus and Mannheimia haemolytica (MH) biotype A serotype 2, was used successfully to reproduce a concurrent disease in West African Dwarf goats. The development of the various pathological features were studied at regular intervals following infection. The acute inflammatory reaction which had developed by day 3 after initial infection was characterised by flooding of the alveoli by neutrophils, oedema, hemorrhage and syncytial cells together with a moderate bronchial and bronchiolar epithelial necrosis. This progressed to a milder acute broncho interstitial pneumonia with giant cells. At this stage, the mucosal immunity were well developed especially the aggregate form of NALT and more of nodular forms of BALT. The organisms were demonstrated with strong immunostaining in the necrotic center, necrotic alveolar wall, fibrin, serous exudate, and degenerated leukocyte in the alveoli and respiratory airways. The bacterial antigens were observed as a strong immunostaining in the blood vessels of the nasal septum, sinusoid in the liver and interstium of the kidney, cytoplasm of alveolar macrophages, pneumocytes, bronchial and bronchiolar epithelium, in the monocytes in the blood vessels. These findings confirmed the enhancement of MH tropism especially in the respiratory tract, liver and kidney. It also showed that West african dwarf goats are highly susceptible to the intratracheal combined infection of PPR virus and MH. The fact that the infection induces strong mucosal responses, this phenomenon can be explored in Africa with the use of combined PPR virus and MH intranasal vaccines to curtail the menace of pneumonia associated with the combined infection on field.  相似文献   

12.
Seven yearling bulls were treated with stressful exercise and intrabronchial Pasteurella haemolytica A1. Group 1 bulls (nos. 1–4) underwent treadmill exercise and, 24 days later, intrabronchial instillation of P. haemolytica A1. Group 2 bulls (nos. 5–7) underwent treadmill exercise, followed 30 min later by intrabronchial P. haemolytica A1. Blood lactic acid values were raised (p<0.05) by treadmill exercise only, but plasma cortisol was raised (p<0.05) by treadmill exercise and by P. haemolytica A1 infection. Neutrophils in bronchoalveolar lavage (BAL) differed from control values 24 h after treadmill exercise, and 1 h and 4 h after P. haemolytica A1 infection.Respiratory disease was more severe and the gross lung lesions were larger in group 2 bulls than in group 1 bulls. P. haemolytica A1 was recovered from the livers, spleens and mesenteric lymph nodes of group 2 but not group 1 bulls, suggesting that group 2 bulls had experienced bacteraemia. Decreased neutrophils in BAL fluid from group 2 bulls at 1 h and 4 h after infection suggests that exercise transiently inhibited neutrophil egress from the blood to the alveoli; BAL neutrophils peaked at 1 h and 4 h after infection in group 1 bulls but declined at 24 h. We conclude that group 2 bulls were made more susceptible to experimental pneumonic pasteurellosis by stressful exercise.Abbreviations ADCC antibody dependent, cell-mediated cytotoxicity - AM alveolar macrophages - BAL bronchoalveolar lavage - CFU conlony-forming units  相似文献   

13.
Summary An investigation of the tick-borne diseases of sheep and goats in the northern regions of the Somali Democratic Republic during the years 1970–72 revealed that Nairobi Sheep disease (NSD), not previously reported in the area, was prevalent. Secondary pneumonia caused byPasteurella haemolytica, was relatively common in sheep suffering from NSD. Heartwater and babesiosis were sporadic and more localised in distribution.
Resumen La investigación de enfermedades transmitidas por garrapatas en ovinos y caprinos en las regiones del norte de la República Democrática de Somalia durante los a?os 1970–1972 reveló la prevalencia de la Enfermedad Ovina de Nairobi (EON), la cual no había sido reportada anteriormente. La neumonía secundaria causada porPasteurella haemolytica, fue común en ovinos que sufrían de EON. La distribución de la enfermedad del hidropericardio “Heartwater” y la babesiosis fue más localizada.
Résumé Une enquête sur les maladies transmises par les tiques aux moutons et chèvres de la Somalie du Nord, faite en 1970–1972, a montré que la Maladie de Nairobi (N.S.D.) qui n'avait pas encore été signalée dans ces régions y accusait une influence considérable. Une pneumonie causée parPasteurella haemolytica a été aussi constatée commune surtout chez les moutons atteints de N.S.D. Rickettsioses et Babesioses sont sporadiques et davantage localisées quant à leur distribution.
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14.
The prevalence and serotypic diversity of Mannheimia [Pasteurella] haemolytica and Pasteurella trehalosi from nasal swabs, sera and abattoir specimens from sheep in the highlands of Wollo, North East Ethiopia was investigated. Prevalence rates of 83% and 75% of these microorganisms were found in the serum samples and nasal swabs, respectively, from apparently healthy sheep. In a local abattoir, 205 lungs were investigated, 34% of which showed pneumonia, from which samples were collected from 51 lungs and the same number of corresponding tonsils. Mannheimia and Pasteurella species were isolated from 59% of these pneumonic lungs and 69% of the respective tonsils. M. haemolytica serotypes accounted for 41 (59%) and P. trehalosi for 11 (32%) of the isolates from the abattoir specimens. The majority (67%) of isolates from nasal swabs were P. trehalosi, M. haemolytica being isolated f rom 4 (13%) of the swabs. M. glucosida was isolated only from the tonsils. The predominant serotypes of the isolates from both the nasal swabs and the abattoir specimens were M. haemolytica A1 (17%) and P. trehalosi T4 (16%) and T3 (13%). P. trehalosi T15 was less commonly encountered, while M. haemolytica A9 and A13 were not isolated. Studies on sera from 100 sheep indicated that antibodies against M. haemolytica serotype A1 (14%) were most common, followed by A5 and A8 (each 10%) and A9 and P. trehalosi T3 (each 9%) and T4 (8%). Antibodies against M. glucosida or serotype A11 occurred in 2% of the sera. Multiple serotypes were common in all types of samples. The importance of including in vaccines the most prevalent serotypes involved in the pneumonia of sheep in the area is discussed.  相似文献   

15.
Light microscope observations on oat cells in the ovine pneumonia-pleurisy complex are presented. This study is based on the experimental production of the disease by viruses and Pasteurella haemolytica. Oat cells appeared only in necrotic lesions associated with large numbers of P. haemolytica in thi pneumonic lung. It is suggested that oat cells originate from blood monocytes, which transform into the oat shape when developing in the necrotic, hypoxic environment created by P. haemolytica. They were not, however, observed to be phagocytic. Oat cells are characteristic of pneumonic pasteurellosis but are not pathognomonic because they can also be found in extrapulmonary locations and in other pathological conditions of the lungs.  相似文献   

16.
Abstract

AIMS: To quantify the number of cells infected with Mannheimia haemolytica and expressing interleukin (IL)-1β, tumour necrosis factor alpha (TNFα) and IL-8 using immunohistochemistry, and to measure the immunoreactivity of cytokines in pulmonary tissue extracts using ELISA, in the lung of lambs experimentally infected with M. haemolytica, and to compare the patterns of expression of cytokines in airways at different times post-infection (p.i.).

METHODS: Twenty 3-month-old lambs of both sexes were randomly assigned to two groups, viz infected (n=15), and uninfected controls (n=5). Each lamb in the infected group was inoculated with 1.5 x 109 cfu M. haemolytica in 5 mL sterile nutrient broth, control lambs were inoculated with 5 mL sterile nutrient broth and clinical signs were monitored. Infected and control animals were killed at 1, 3, 5, 7, and 15 days p.i. Histopathology and immunohistochemistry were conducted to determine the number of immunolabelled cells in pneumonic lungs, and study the pattern of expression of IL-1β, TNFα and IL-8 in lung extracts using ELISA.

RESULTS: Lesions in bronchi and bronchioles ranged from epithelial desquamation to bronchiolitis obliterans and necrosis. The alveoli had areas of seroproteinaceous fluid, fibrin and bacterial aggregates that evolved to foci of pyogranulomatous inflammation with clustered inflammatory cells, referred to as ‘oat cells’. M. haemolytica antigen was observed in the cytoplasm of inflammatory cells. Labelling of IL-1β, TNFα and IL-8 was observed in bronchial and bronchiolar epithelial cells, alveolar exudate, and in interstitial inflammatory infiltrate, with increased expression on 1 and 3 days p.i. for IL-1β and TNFα, and 1, 3, and 5 days p.i. for IL-8. In lung tissue extracts, peak concentrations of IL-1β (55 (SD 5) ng/mL), TNFα (92 (SD 6) pg/mL) and IL-8 (8 [SD 2] μg/mL) occurred at 3 days p.i.

CONCLUSIONS: The results of this study suggested that the inflammatory cytokines IL-1β, TNFα and IL-8 may play an important role in enhancing the biological response to M. haemolytica, and contribute to the development of lesions in the lung in pulmonary pasteurellosis in sheep. Given that the expression of IL-8 in lung was much greater than that of IL-1β and TNFα, anti-cytokine agents directed at this mediator could be useful in the prevention and treatment of this disease.  相似文献   

17.
Distribution of erythromycin into subcutaneous tissue chambers was characterised pharmacokinetically and the effect of Pasteurella haemolytica infection on the extent of penetration was studied. Thermoplastic tissue chambers were implanted subcutaneously in the paralumbar fossae of six calves. Thirty-five days after implantation, the tissue chamber distribution of intramuscularly administered erythromycin (30 mg kg−1) was studied. Chambers were then inoculated with P haemolytica and the tissue chamber pharmacokinetics of erythromycin were again studied. Diffusion of erythromycin into tissue chambers was best described using a two-compartment model with tissue chambers representing a relatively inaccessible compartment. Despite changes in chamber fluid pH, the extent of erythromycin penetration into chambers was not affected by P haemolytica inoculation. Comparison of computer simulated concentration-time curves resulting from different routes of administration revealed that penetration of erythromycin into less accessible sites was more likely to be higher after intravenous administration than after intramuscular administration.  相似文献   

18.
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19.
A flock of New Zealand Romney lambs on a property in Hawkes Bay was examined from August 1978 to June 1979. In November, the lambs in the flock were allocated to groups as follows: 600 lambs from which groups were selected for slaughter by commercial criteria each month (selected groups); 700 lambs which were subdivided into 8 groups (random groups), one of which was sent for slaughter each month; and 25 lambs to monitor serological responses to viral infections (surveillance group). At slaughter, lesions in the anterior lobes of the lungs were classified into small, large or mottled lesions while those in the posterior regions of the diaphragmatic lobes comprised a separate group. The prevalence of the pneumonic and pleural lesions was recorded in all groups of lambs. Pneumonic lesions in lambs from the random groups were further classified after microscopic examination. The prevalence of infections with parainfluenza virus type 3, adenoviruses, Mycoplasma spp., and Pasteurella haemolytica was also recorded in the random groups. Average carcase weights of all groups of lambs were also recorded.

The prevalence of large lesions in the anterior lobes, pleural lesions and devaluation of carcases due to pleural lesions was significantly lower in the selected than in the random groups.

In the random groups, the prevalence of small lesions in the anterior lobes of the lungs was high and was not always associated with infections with the viruses, P. haemolytica or Mycoplasma spp. Microscopically, these lesions could he divided into four types as previously described. The prevalence of large lesions in the anterior lobes was low in November but increased to peak levels in February and March and then declined to intermediate levels. The prevalence of large lesions was associated with that of infections with the micro-organisms and significantly more large lesions contained P. haemolytica and Mycoplasma spp. than did small lesions or normal lungs. The prevalence of large lesions also appeared to be inversely related to the average carcase weights of the lambs. Most large lesions were similar on microscopy to those of “enzootic” or “atypical” pneumonia but were divided into four types on the basis of exudative and proliferative features. The prevalence of mottled lesions in the anterior lobes was low throughout the period of observation but peaks were observed in January and May. The peaks were associated with adenovirus infection and elevated prevalence of infection with P. haemolytica and Mycoplasma spp. Significantly more mottled lesions contained P. haemolytica than did small lesions or normal lungs. Microscopically, most mottled lesions were similar to exudative large lesions.

Lesions in the posterior diaphragmatic lobes were most numerous in November and from April to June. Their prevalence appeared to be related to anthelminthic treatment and environmental conditions. Microscopically, these lesions were typical of those following infection with Dictyocaulus filaria.  相似文献   

20.
Summary

The minimal inhititory concentration (MIC) of tilmicosin and oxytetracycline was dertermined for Pasteurella haemolytica isolated from Dutch cattle in 1991. The agar dilution method was used. Of the Pasteurella haemolytica strains examined, 96% (24) had a MIC for tilmicosin of 2 μg/ml or lower; in one strain the MIC was 8 μg/ml. The MIC for oxytetracycline was equal to or higher than 64 μg/ml in 19 strains (76%), whereas for 5 strains the MIC was 1 μg/ml and for 1 strain 2 μg/ml.  相似文献   

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