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1.
In a study of 4 sheep herds, 1 apparently healthy and 3 having respiratory problems, lesions typical of subacute or chronic pneumonia were found in 3–36 % of slaughtered lambs. Occurrence appeared to be related to certain environmental factors such as pasture, whereas moderate lungworm invasion was not found to contribute to subacute or chronic pneumonia. Relation between pneumonia and low carcass weight was established only in 1 herd.Lungs were subjected to microbiological examination. Mycoplasma ovipneumoniae was isolated from both normal and pneumonic lungs from all 4 herds. The prevalence was far higher in pneumonic (98 %) than in normal ones (28 %). Bacteria, mostly Pasteurella haemolytica, were also found in both pneumonic (49 %) and normal (18 %) lungs from all 4 herds. These results confirm the conclusions of a previous study that M. ovipneumoniae is of etiological significance in subacute or chronic pneumonia, whereas bacteria mainly occur as secondary invaders. M. ovipneumoniae appears, however, only to be a potential pathogen. Examinations for Mycoplasma arginini and virus were negative and these agents are considered to be of less significance in subacute or chronic pneumonia under Norwegian conditions.  相似文献   

2.
Lungs from 191 slaughter pigs with gross lesions indicative of enzootic pneumonia of pigs (EPP) and 80 grossly normal lungs, all originating from 9 different herds, were subjected to microbiological and pathological examinations. The microbiological studies included both bacterial and mycoplasmal culture and also testing for Mycoplasma hyopneumoniae antigen in tissue by indirect immunofluorescent technique. M. hyopneumoniae, Pasteurella multocida and Mycoplasma hyorhinis were detected in 83%, 43% and 37% of the pneumonic lungs, respectively. Mycoplasma flocculare was the most frequently isolated organism in the non-pneumonic lungs. The greatest amounts of macroscopic pneumonia (25.2%) were recorded in lungs with all the three agents M. hyopneumoniae, P. multocida and M. hyorhinis present. The amounts of pneumonia in lungs with M. hyopneumoniae alone and in concurrence with P. multocida, were 9.3% and 15.6%, respectively. M. hyorhinis was also, in this study, associated with higher frequency of diffuse pleuritis. These findings indicate that M. hyorhinis might be involved in the pathogenesis of pneumonia in slaughter pigs. Ninety-six per cent of the isolates of P. multocida from pneumonic lungs could be characterized as type A. In the herds which had the most severe pneumonia problems, toxin production was detected in 83% of the P. multocida strains while only 28% were toxigenic in herds with subclinical to moderate pneumonia problems.  相似文献   

3.
In order to study the occurrence of mycoplasmas among Norwegian sheep, lungs from a great number of different herds were collected at 3 abattoirs in Southern Norway. The presence of fermenting mycoplasmas and bacteria was examined in both normal and pneumonic lungs to determine whether recovery of these agents could be related to pneumonic changes. Pneumonic lungs demonstrated lesions typical of the condition described as subacute or chronic pneumonia.Mycoplasma ovipneumoniae was found in 87 % of the 126 pneumonic lungs and in 6 % of the 83 normal lungs. Bacteria, mostly Pasteurella haemolytica, were less frequently encountered in the pneumonic lungs, and usually in combination with M. ovipneumoniae. It is concluded that M. ovipneumoniae is widespread among sheep in Southern Norway and can be considered to have etiological significance in subacute or chronic pneumonia, whereas bacteria probably occur mainly as secondary invaders. Changes resulting from moderate invasion by lungworm were found in about half of the lungs, but just as frequently in normal as in pneumonic lungs, and accordingly did not appear to contribute to the pneumonia investigated.  相似文献   

4.
The virulence of isolates of Mycoplasma ovipneumoniae and M. arginini from pneumonic and unaffected ovine lungs was compared in a mouse mammary gland model. The isolates varied in their ability to induce a neutrophilic response in the mammary gland. A moderate to severe form of mastitis was induced by 3 M. ovipneumoniae isolates recovered from pneumonic lungs, while the remaining M. ovipneumoniae isolates from pneumonic lungs and those from unaffected lungs induced a very mild histopathological response. The severity of the mastitis could not be increased by the simultaneous inoculation of a mixture of 5 mycoplasma isolates. Mycoplasma arginini isolates induced only a very mild histopathological response despite having been isolated from pneumonic lungs. The finding that the 3 most virulent M. ovipneumoniae isolates were initially recovered from pneumonic ovine lungs suggested that these virulent isolates may contribute to ovine pneumonia. However, the isolation of M. ovipneumoniae from pneumonic ovine lungs does not necessarily imply that these organisms are the causal agents, since M. ovipneumoniae isolates may vary in virulence.  相似文献   

5.
Chronic bronchopneumonia in lambs, also known as 'atypical' or 'chronic, non-progressive' pneumonia is a common, frequently sub-clinical disease affecting animals under 12-months-old in intensive production systems. Infection with both Mycoplasma ovipneumoniae and Mannheimia haemolytica have been implicated in the aetiology of this condition and a variety of pulmonary lesions can result. In this study, detailed laboratory examination of 30 abattoir-derived lungs with the characteristic gross features of atypical pneumonia (AP) was carried out with a view to refining and correlating the histopathological and microbiological criteria required for the diagnosis of this disease. For the first time a broad range of laboratory detection techniques including bacterial and virus isolation, fluorescent antibody tests and immunohistochemistry were used in parallel to identify potential causative pathogens such as M. ovipneumoniae, M. haemolytica, parainfluenza type-3 (PI3) virus and respiratory syncytial virus (RSV) in AP lesions. The most consistent finding was the association of gross AP lesions with M. ovipneumoniae, identified by either culture or immunohistochemistry in 27 (90%) of the 30 cases. However the presence M. ovipneumoniae organisms or antigen did not consistently correlate with particular histopathological changes. Furthermore, peri-airway lymphoid hyperplasia, intra-alveolar exudation and nodular 'hyaline scars', which are all previously reported microscopic lesions of AP, were not identified in 12 (40%) of the cases and isolation of M. haemolytica was over-represented in lungs exhibiting suppurative lesions. These findings illustrate the complex aetiopathogenesis of this disease and highlight the requirement to use a combination of diagnostic criteria in its laboratory diagnosis.  相似文献   

6.
The heterogeneity of Mycoplasma ovipneumoniae isolates from the lungs of sheep with chronic non-progressive pneumonia (CNP) from the same flock raised the possibility that multiple isolates derived from one lung were not all identical. To test this hypothesis, thirty isolates were obtained from each of six pneumonic sheep lungs at slaughter. Four lungs had relatively severe lesions and from each of these, three or four strains of M. ovipneumonia, distinguishable by REA and in most cases by SDS-PAGE, were detected. From the lungs of each of two sheep with mild lesions, two strains of M. ovipneumoniae were detected. Four isolates from one lung were further examined by restriction endonuclease analysis (REA) using many restriction endonucleases. Those which differed with EcoRI also differed when other restriction endonucleases were used. However, partial digests occurred mainly with those restriction endonucleases which recognise cytosine-rich sequences. The presence of multiple strains of one species of microorganism in individual lesions is an unusual concept which may not be limited to one disease or to one host.  相似文献   

7.
Blood samples from 777 pigs, originating from 9 different herds, were collected at slaughter and examined for antibodies to Mycoplasma hyopneumoniae and Actinobacillus (Haemophilus) pleuropneumoniae by the indirect hemagglutination assay (IHA) and the complement fixation (CF) test, respectively. Results were compared to pathological and microbiological findings. Antibodies to M. hyopneumoniae in positive titers of 1/80 or higher were found in 62% of the samples. The relationship between positive IHA titers to M. hyopneumoniae and gross findings indicative of enzootic pneumonia of pigs (EPP), histological findings indicative of EPP, the isolation of M. hyopneumoniae and the demonstration of M. hyopneumoniae by indirect immunofluorescent testing ranged from 64% to 68%. No correlation was noted between positive IHA titers and the isolation of Mycoplasma flocculare. Positive antibody titers to A. pleuropneumoniae of 1/10 or higher were detected in 5% to 85% of the samples from individual herds. Positive titers to A. pleuropneumoniae serotype 2 were found in 71% to 79% of the sampled animals from herds with high frequencies of pneumonic lesions indicative of pleuropneumonia. In herds with low frequencies of pleuropneumonia, positive titers were recorded in from 0 to 4% of the tested pigs. However, no statistical association was found between pleuropneumonia and positive titers to A. pleuropneumoniae serotype 2 in individual animals. Twenty-one per cent of samples with positive CF titers to A. pleuropneumoniae showed antibodies to more than one serotype.  相似文献   

8.
Chronic non-progressive pneumonia (CNP) is a common disease which affects lambs in New Zealand during late summer and autumn. Mycoplasma ovipneumoniae can be recovered from a high proportion of lesions but it is also present in some normal lungs. Bacteria, especially Pasteurella haemolytica, can also be recovered from more than half the lungs of affected animals. Isolates of M. ovipneumoniae are genetically heterogeneous, as demonstrated by examination of their DNA or total cellular proteins, and are serologically heterogeneous as shown by metabolic inhibition tests. The number of strains present in New Zealand is large and several distinguishable strains can be recovered from each affected lung. Mycoplasma ovipneumoniae has pathogenic potential as indicated by its ability to produce hydrogen peroxide, cause ciliostasis and by its possession of a capsule. Chronic non-progressive pneumonia can be transmitted consistently to over 50% of lambs by inoculation of pooled pneumonic lung homogenate and transmission can be suppressed by broad spectrum antibiotics. In contrast, penicillin does not prevent the development of lesions but diminishes their severity. Pooled lung homogenate treated with digitonin, which inactivates mycoplasmas, has failed to transmit CNP. Pure cultures of M. ovipneumoniae produce only mild lesions in some animals, whereas inoculation with pooled lung homogenate (from which no viruses were isolated) containing mixed strains of M. ovipneumoniae and free from bacteria, is more effective in producing lesions. Research work to date suggests that CNP may be initiated by colonisation of the lung by M. ovipneumoniae which causes ciliostasis and elicits an exudate allowing colonisation of the lungs by bacteria especially M. haemolytica and by other strains of M. ovipneumoniae. The immune response to the initial strain of M. ovipneumoniae may inhibit its replication but would be less effective in inhibiting heterologous strains of the organism allowing their sequential replication. Eventually production of a broad immune response to M. ovipneumoniae would lead to its elimination which in turn would facilitate the elimination of other microorganisms and the resolution of lesions. As natural immunity to CNP occurs within the first year, it may be possible to develop an effective and useful vaccine. Such a vaccine may need to include multiple strains of M. ovipneumoniae.  相似文献   

9.
Mycoplasma ovipneumoniae and Mycoplasma arginini were the species of Mollicutes most commonly isolated from 175 goats with respiratory disease in Ontario. The pathogenicity of M. ovipneumoniae, strain B321B and M. arginini, strain D53e, was assessed in goats following endobronchial inoculation. One out of three two year old goats developed fever after inoculation with a pure culture of strain B321B, and it had extensive subacute fibrinous pleuritis when necropsied three weeks later. Neither of the remaining goats had lesions in the respiratory tract. Mycoplasma ovipneumoniae was recovered from one of the animals four days after inoculation, but not at necropsy from any of the goats, at which time a marked humoral immune response with growth inhibiting antibodies was detected. In a second experiment three four to five week old goats were inoculated with the same strain and three other goats were given placebo treatment. One experimental goat developed fever and coughing, and it had extensive subacute fibrinous pleuritis in the right side and pneumonia. Another goat had focal pneumonia in the left diaphragmatic lobe. Microscopically there was subacute hyperplastic suppurative bronchiolitis, atelectasis and nonsuppurative alveolitis. The infected animals did not clear the mycoplasma and not all of them produced antibodies. Mycoplasma arginini, strain D53e, did not induce lesions in any of four goat kids within 14 days after inoculation but did cause transient elevations in rectal temperature, circulating monocytes, circulating neutrophils and blood fibrinogen. Mycoplasma arginini was infective and immunogenic for all inoculated animals and showed a particular affinity for the tonsil. Thus, this study provides the first evidence that M. ovipneumoniae is pathogenic for goats causing pneumonia and pleuritis.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

10.
Extensive pneumonic lesions were present in 42 out of 43 calves obtained for post mortem examination from 34 outbreaks of respiratory disease in Northern Ireland. Bronchiolitis and alveolitis with necrosis of bronchiolar mucosa which progressed to bronchiolitis obliterans and peribronchiolar fibrosis were prominent histopathological features in the lungs of calves obtained live. The majority of calves which died within the first two months of these outbreaks had severe exudative bronchopneumonia with marked vascular damage and necrosis of pulmonary parenchyma. Pasteurella spp, Mycoplasma spp and P13 virus were the organisms most frequently recovered from the pneumonic lungs.  相似文献   

11.
The prevalence and pathomorphology of gross lung lesions were studied in 855 slaughter weight pigs from 9 selected herds in south-eastern Norway. Pneumonic or pleuritic lesions were found in 84% of the lungs, ranging from 37% in the least affected herd to 97% in the one most affected. Bronchopneumonia indicative of a primary Mycoplasma hyopneumoniae infection was found in 70% of the lungs, ranging from 9% to 82% in the individual herds. The amount of bronchopneumonic lesions in individual lungs ranged from 0 to 69%, with an average of 7.8%. Pleuropneumonia indicative of Actinobacillus (Haemophilus) pleuropneumoniae infection was found in 29% of the lungs ranging from 0 in the least affected herd to 58% in the most affected. Diffuse pleuritis was found in 41% of the lungs and the prevalence ranged from 4% to 63%.  相似文献   

12.
Attempts were made to recover and serologically identify mycoplasmas from the lungs of 50 pigs with mycoplasmal pneumonia and from 50 lungs without gross evidence of pneumonia. Mycoplasma hyopneumoniae and M. hyorhinis were respectively cultured from 30% and 50% of pneumonic lungs and the former species was also recovered from 12% of non-pneumonic lungs. Three other isolates (one from pneumonic and two from non-pneumonic lungs) differed in colonial morphology from M. hyopneumoniae and M. hyorhinis. The viability of these isolates could not be maintained on subculture and they were not identified serologically. The indirect immunofluorescence test was found to be highly specific for the identification and differentiation of M. hyopneumoniae and M. hyorhinis.  相似文献   

13.
The degree to which histopathological lesions correlated with the numbers of M. ovipneumoniae and bacteria was studied in sixty 6 to 9 month-old lambs with chronic and subacute pneumonia slaughtered at a local meatworks. Large numbers of M. ovipneumoniae were associated with chronic proliferative changes such as peribronchiolar fibrosis and alveolar interstitial thickening. The combined effect of large numbers of M. ovipneumoniae and bacteria were associated with neutrophilic exudation and epithelial hyperplasia. However, lymphoid hyperplasia and excess mucus production were associated with low bacterial titres. There was no direct correlation between the numbers of M. ovipneumoniae and bacteria present in the pneumonic lungs.  相似文献   

14.
Mycoplasma bovis is an important cause of calf pneumonia worldwide. In this study, we examined 140 cattle at slaughter comprising 70 veal calves and 70 beef cattle; 115 animals with pneumonic lesions and 25 without. Lung samples were submitted for bacteriological, histological, and M. bovis-immunohistochemical analyses. Serology for M. bovis was positive in 76% of beef cattle and 100% of veal calves. M. bovis was isolated only from veal calves in 16 out of 64 pneumonic cases. M. bovis was detected by immunohistochemistry in seven bacteriologically positive cases. M. bovis antigen was associated with bronchogenic necrosuppurative or fibrinonecrotizing lesions. Bacteriologically positive and immunohistochemical negative cases were associated with catarrhal bronchointerstitial pneumonia. Results suggest that M. bovis infection may develop into a severe necrosuppurative bronchopneumonia or fibrinonecrotizing pneumonia when associated with a high number of intralesional organisms or, conversely, into a mild catarrhal bronchointerstitial pneumonia when associated with a low number of organisms.  相似文献   

15.
Between 1990 and 2000, more than 1600 mycoplasmas and the related acholeplasmas were identified from ruminant animals by the Mycoplasma Group at the Veterinary Laboratories Agency--Weybridge. Mycoplasma bovis was the most commonly identified pathogen, mostly from pneumonic calves but occasionally from cattle with mastitis and arthritis. Mycoplasma canis was first isolated in Britain in 1995 from pneumonic calves and the number of isolates increased to 18 per cent of the total mycoplasmas isolated from cattle in 1999. The ELISA for antibodies to M. bovis detected 1971 positive samples (22 per cent) among 8959 serum samples, mainly from pneumonic cattle. Other mycoplasmas identified included Mycoplasma dispar from the lungs of cattle with respiratory disease, and Mycoplasma bovigenitalium from the reproductive tract of cows with vulvovaginitis and infertility. Mycoplasma bovirhinis and Acholeplasma species were found commonly but are thought to be more opportunistic than pathogenic. In sheep and goats, the majority of Mycoplasma species isolated were identified as Mycoplasma ovipneumoniae from pneumonic sheep, Mycoplasma conjunctivae from sheep with keratoconjunctivitis, and the ubiquitous Mycoplasma arginini.  相似文献   

16.
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   

17.
Microbiological and serological studies on caprine pneumonias in Oman   总被引：9，自引：0，他引：9  
Eight of 10 typical cases of contagious caprine pleuro-pneumonia in Oman yielded strain F38-like mycoplasmas from the lungs in high titre, but no other mycoplasmas: both negative animals had been treated with tylosin shortly before death. Among 21 other lungs examined three of six cases of acute pneumonia yielded Mycoplasma ovipneumoniae; one also yielded M capricolum. M ovipneumoniae was also isolated from all eight cases of chronic pneumonia sampled from an abattoir, and from the lungs of three animals which died without overt signs of pneumonia. A single isolate of M arginini and three of unidentified mycoplasmas were also obtained from goats with and without pneumonia. Various bacterial species were isolated, none of which predominated. Antibodies to M mycoides subspecies capri (M m capri) and strain F38 were detected in sera from eight different sources. Assuming titres of 1 in 40 or more as positive in the indirect haemagglutination test used, 29 per cent of 422 serum samples had antibodies to M m capri alone, 2.6 per cent to strain F38 alone and 3.6 per cent to both organisms. These results confirm the presence of F38-like mycoplasmas in Oman, and indicate also widespread infection with M m capri. The role of the latter in caprine pneumonias in Oman requires elucidation.  相似文献   

18.
BITSCH, V., N. F. FRIIS and H. V. KROGH: A microbiological study of pneumonic calf lungs. Acta vet. scand. 1976, 17, 32–42.–Fifty pneumonic calf lungs were subjected to microbiologic screening with regard to bacteria, mycoplasmas, and viruses.Of bacteria the species most commonly found were Pasteurella multocida (eight lungs), Pasteurella hemolytica (eight lungs), and Corynebacterium pyogenes (13 lungs). Of special interest was the demonstration of Neisseria spp. in five lungs. Mycoplasma dispar was found in 31 lungs, Mycoplasma bovirhinis in 16 lungs, and Urea-plasma in 26 lungs. Cytopathogenic agents were demonstrated in 14 lungs. Four isolates were found to be bovine respiratory syncytial virus, three were bovine viral diarrhea virus, and two were bovine parainfluenza 3 virus. The remaining five cytopathogenic agents were not identified.  相似文献   

19.
Mycoplasma bovis is perceived as an emerging cause of mortality in feedlot beef cattle. This study examined the lesions and infectious agents in naturally occurring M. bovis-associated bronchopneumonia and arthritis and the relationship of this condition with bovine viral diarrhea virus (BVDV) infection. Standardized pathologic, immunohistochemical, and microbiologic investigations were conducted on 99 calves that died or were euthanized within 60 days after arrival in 72 feedlots. Cranioventral bronchopneumonia with multiple foci of caseous necrosis was identified in 54 of 99 calves, including 30 with concurrent fibrinosuppurative bronchopneumonia typical of pneumonic pasteurellosis. Mycoplasma bovis was consistently identified in these lesions by culture and immunohistochemistry, but also commonly in healthy lungs and those with pneumonia of other causes. Focal lesions of coagulation necrosis, typical of pneumonic pasteurellosis, were often infected with both Mannheimia haemolytica and M. bovis. Arthritis was present in 25 of 54 (46%) calves with M. bovis pneumonia, and all calves with arthritis had pneumonia. BVDV infection was more common in calves with lesions of bacterial pneumonia than in those dying of other causes, but BVDV infection was not more common in calves with caseonecrotic bronchopneumonia than those with fibrinosuppurative bronchopneumonia. Retrospective analysis identified cases of M. bovis pneumonia in the early 1980s that had milder lesions than the current cases. The findings suggest that, in at least some calves, M. bovis induces caseonecrotic bronchopneumonia within the lesions of pneumonic pasteurellosis.  相似文献   

20.
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   

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