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1.
Between 1997 and 2000, a total of 150 healthy cattle and 238 animals with respiratory disease were examined for six Mycoplasma species. Attempts were made to detect Mycoplasma canis, Mycoplasma dispar and Ureaplasma diversum in calves with recurrent disease, and all three of these species were identified in calves with recurrent disease and in healthy lungs. In healthy calves, 84 per cent of bronchoalveolar lavage fluids were mycoplasma free; when cultures were positive, Mycoplasma bovirhinis was the only species isolated. Mycoplasmas were isolated from 78 per cent of animals suffering recurrent respiratory disease and from 65 per cent of acute respiratory cases. Mycoplasma bovis was isolated from bronchoalveolar lavages from 35 per cent of calves suffering recurrent respiratory disease, and from 50 per cent of acute cases, and from 20 per cent of pneumonic cases examined postmortem. M bovis was associated with other Mycoplasma species in 44 per cent of cases. M dispar was also isolated from 45.5 per cent of calves suffering recurrent respiratory disease, often in association with M bovis. M canis was identified for the first time in diseased Belgian cattle. Other mycoplasmas, including Mycoplasma arginini, Mycoplasma alkalescens and U diversum, were isolated less frequently. Associations between mycoplasmas and other pathogens were often observed. Among lungs infected with Pasteurella and/or Mannheimia species, more than 50 per cent were mixed infections with M bovis.  相似文献   

2.
Mycoplasmas isolated from bovine mastitis in California were classified into five distinct species. These included Mycoplasma bovis, M. bovigenitalium, M. alkalescens, M. canadenfe, and an unidentified strain, ST-6. Strains frequently recovered from the nose of young calves proved to be M. arginini, M. bovirhinis was recovered from the respiratory tract but was not a common finding.  相似文献   

3.
A retrospective study of Mycoplasma otitis in California calves submitted for necropsy between 1993 and 2002 was conducted to characterize the demographic features of the disease and the pathologic findings associated with infection. Sixty-one confirmed cases of Mycoplasma otitis were identified among 20,525 necropsied cattle. All affected animals were calves, ranging in age from 2 weeks to 4 months and with a median age of 1.5 months. Ninety-two percent of the cases were dairy breeds. A higher percent of necropsied calves with Mycoplasma otitis were males (0.45%) than females (0.23%). The proportion of cases that had Mycoplasma otitis increased from 1993 to 2002, and there was a significant (P < 0.05) seasonal distribution, with the highest proportion in the spring and the lowest in the summer months. Infections involved both the middle and inner ear and were characterized by a suppurative inflammatory response with extensive bony involvement. Three species of Mycoplasma were isolated from the ears: M. bovis, M. bovirhinis, and M. alkalescens. Concurrent pneumonia occurred in 47 cases (77%), and Mycoplasma was isolated from the lungs of 30 of those cases. The increasing proportion of Mycoplasma otitis cases in the past 10 years emphasizes the importance of identifying risk factors that could be modified to lower the incidence of this disease in calves.  相似文献   

4.
Prevalence of mycoplasmas in the respiratory tracts of pneumonic calves.   总被引：2，自引：0，他引：2  
The prevalence of mycoplasmas in the respiratory tracts of 148 pneumonic calves originating from 25 herds in the Netherlands is reported. Four types of culture media were used to isolate mycoplasmas: solid modified Edward medium, 2 types of Friis media, and A7B differential agar medium. Mycoplasmas were isolated both from nasal swab specimens and lung lavage fluids collected from live calves and from nasal mucosa and lung tissue specimens collected post mortem. All of the mycoplasma strains isolated could be identified as either Ureaplasma diversum (isolated from 80% of 25 herds), Mycoplasma dispar (92%), M. bovirhinis (88%), M. bovis (20%), M. bovigenitalium (4%), M. arginini (16%), or M. canis (12%). Isolation rates of M. dispar and U. diversum were considerably higher from lung lavage fluids than from nasal swab specimens. M. bovis was detected only in fattening herds and not in dairy herds. The respiratory tracts of 75% of the calves examined contained at least 2 mycoplasma species. In total, 25 different combinations of mycoplasma species were detected in specimens collected from noses and lungs. The pathogenic species U. diversum and M. dispar had not been isolated before in the Netherlands.  相似文献   

5.
This report describes the incidence of Mycoplasma dispar, ureaplasma and conventional (large colony) mycoplasma isolated from the pneumonic lungs of groups of young calves and the identification to species level of mycoplasmas in mixed populations with the aid of the indirect fluorescent antibody test. Pneumonic lung tissue yielded one or more mycoplasma species from 88% of the 153 calves cultured. The mycoplasmas identified and percent of the calves with lungs positive for each species were: M. dispar (56%), ureaplasma (44%), Mycoplasma bovis (37%), Mycoplasma arginini (33%) and Mycoplasma bovirhinis (23%). Conventional mycoplasmas isolated from two calves (1%) could not be identified using the antisera available.  相似文献   

6.
Serial nasopharyngeal swab and bronchoalveolar lavage cultures were used to estimate changes in the bacterial flora of the respiratory tracts of calves during the first month after arrival in the feedlot. Bronchoalveolar lavage (BAL) differential cell counts served to evaluate pulmonary inflammatory changes during this period. Two groups of calves were studied, one consisting of clinically normal controls (n = 60), the other, of cases (n = 59) which received treatment for respiratory disease (penicillin +/- trimethoprimsulfadoxine). A variety of organisms, including Pasteurella multocida, Pasteurella haemolytica, Haemophilus somnus, Mycoplasma bovis and Mycoplasma bovirhinis, were present in the upper and lower airways of both groups during the postarrival period. With the exception of M. bovis, an overall decline in the prevalence of these organisms was observed during the course of the study. In cases, there was a marked decrease in the number of Pasteurella spp. and H. somnus isolates immediately following treatment. For the Pasteurella spp., however, this effect was shortlived as they often appeared to recolonize the respiratory tract within eight days of terminating antimicrobial therapy. Treatment did not appear to affect the frequency of isolating M. bovis. Its prevalence, in both groups of calves, increased to levels approaching 100% during the course of the study. All Pasteurella spp. isolates were tested for susceptibility to several commonly used antimicrobials. Resistance was only evident among P. haemolytica isolated from cases and in every instance this was to a combination of penicillin, ampicillin and tetracycline. Significantly more isolates were resistant after treatment than before. There were BAL differential cell count abnormalities indicative of inflammation in both cases and controls.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

7.
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   

8.
Mycoplasma alkalescens, M. bovigenitalium, M. bovirhinis and M. bovis were directly detected from milk specimens by a polymerase chain reaction (PCR) when milk specimens were centrifuged and treated with mycoplasmal lysis buffer. The sensitivity of this PCR method was 110 to 1,400 colony forming units (CFU). This method was useful for the detection of mycoplasmas in milk specimens from cows at an early stage of mycoplasmal mastitis since a small amount of mycoplasma could be detect in milk without culture. The results were available within 12 hr, which is faster than conventional culture techniques. M. bovirhinis was detected in more than 70% of mastitic milk specimens when mycoplasmas were detected in milk specimens from 30 cows with mastitis by this PCR method.  相似文献   

9.
本研究旨在调查新疆喀什某规模化奶牛场的犊牛死亡原因,并确定病原体.无菌采集3份因肺炎死亡的犊牛肺脏病料样品.采用牛支原体专用液体培养基和1.0%牛支原体琼脂固体筛选培养基从3份病死犊牛肺脏病料中分离得到2株牛支原体(Mycoplasma bovis,M.bovis),分别命名为M.bovis-NJ-1和M.bovis-NJ-2.通过菌落形态学观察、特异性PCR和oppF测序比对对分离株进行鉴定.结果显示,2个分离株在固体培养基上的菌落呈现典型的"煎蛋状",且Dienes染色特点符合牛支原体菌落着色特征,中心呈深蓝色;PCR能扩增出牛支原体特异的448 bp目的片段;2个分离株的oppF基因序列与牛支原体国际标准株PG45的同源性分别为96.7%和95.3%.结果表明,引起犊牛发病死亡的病原是牛支原体,本研究为犊牛支原体肺炎的快速诊断和防制提供依据.  相似文献   

10.
Cloned cultures of 16 strains, representing nine different species of Mycoplasma and Acholeplasma, were inoculated intratracheally into gnotobiotic calves. Strains of M bovirhinis, M canadense, M verecundum, A axanthum and A modicum did not produce visible pneumonic lesions and were not reisolated from the lungs. Strains of M alkalescens and M arginini colonised the lower respiratory tract but failed to produce visible pneumonia. M bovigenitalium (strain M991/70) and M dispar (strain Gri226) both colonised the respiratory tract and induced pneumonic lesions estimated to involve up to 8 per cent (M bovigenitalium) and 17 per cent (M dispar) of the lung. Histologically M bovigenitalium produced a cuffing pneumonia and M dispar produced a interstitial alveolitis.  相似文献   

11.
A total of 247 mycoplasma strains was isolated from 435 lungs, tracheobronchial secretions and nasal swabs originating from cattle with symptoms of bronchopneumonia. Mycoplasma (M.) bovis was found 89 times (36%) and was the most common mycoplasma species in the lungs. M. bovirhinis, M. bovigenitalium, M. spec. and Acholeplasma (A.) laidlawii were isolated 158 times (64%). Among these mycoplasmas M. bovirhinis was the most widespread species (114 isolations). In 55 cases (62%) M. bovis was associated with Pasteurella or Actinomyces (A.) pyogenes. The other mycoplasma species were found in 67 cases (42%) together with these bacteria. Without mycoplasmas Pasteurella and A. pyogenes occurred in 33 of the probes investigated (21%). Beside mycoplasmas Haemophilus (H.) somnus was isolated from 16 of 162 tracheobronchial secretions investigated. The results confirm earlier suppositions that in most of the cases bronchopneumonia of cattle is a multifactorial event, frequently associated with mycoplasmas--especially M. bovis.  相似文献   

12.
The population under study included young calves with pneumonia (group A, n = 13) and their controls (group B, n = 9), as well as older calves from which the lungs with (group C, n = 90) or without (group D, n = 10) lesions were collected after slaughter. Arcanobacterium pyogenes was the organism most commonly isolated from calves in group A (46%), followed by Haemophilus somnus (23%), Mannheimia haemolytica (15%), Streptococcus suis and Pasteurella multocida (7.7% each). Only S. suis (22%) and P. multocida (11%) were found in group B. P. multocida was isolated from 32% group C calves, H. somnus from 11%, A. pyogenes from 7.8%, M. haemolytica from 2.2% and S. suis from 1.1%. No specific pathogens were isolated in group D. Prevalence of Mycoplasma bovis infection was 69% in group A and 37% in group C. Ninety-eight strains were tested for resistAnce to antibiotics. Resistance to penicillin and ampicillin was present only in M. haemolytica (46%). High percentages of resistant strains were observed for streptomycin (48-100%), tetracycline (15-43%), sulfonamides alone (14-100%) or in combination with trimethoprim (0-100%). Therapeutic approaches to bacterial calf pneumonia in the area under study should be modified according to the isolated bacterial population, the observed antimicrobial resistances and the growing importance of Mycoplasma bovis.  相似文献   

13.
Mycoplasma alkalescens-induced arthritis in dairy calves   总被引：1，自引：0，他引：1  
Mycoplasma alkalescens was isolated from 6 of 7 synovial fluid samples taken by arthrocentesis from 3-week- to 4-month-old Holstein-Friesian calves with severe arthritis (tibiotarsal or carpal joints). Approximately 30 of 215 calves in the herd were affected. In one 6-week-old calf, M alkalescens was isolated from the liver, right tibiotarsal joint, right and left popliteal lymph nodes, and an exposed umbilical artery. Intraarticular inoculations of broth cultures of M alkalescens initially induced a febrile response and then severe fibrinopurulent arthritis. Intravenous inoculation of M alkalescens induced only a febrile response. The natural disease may have been a complication of umbilical exposure to M alkalescens, causing omphaloarteritis and subsequent arthritis. Before and during the arthritis problem, the umbilicus of newborn calves was dipped in an organic iodine product with 10% glycerin, marketed as a postmilking teat dip. After the cause of the arthritis was determined, the umbilicus of each newborn calf was treated with 7% tincture of iodine and no new cases of arthritis occurred.  相似文献   

14.
The clinical pattern as well as the pathologico-anatomic or histological changes due to mycoplasma mastitis are neither specific nor pathognomic. Mastitis pathogens so far described included M. bovis, M. bovigenitalium, A. laidlawii, A. axanthum, M. alkalescens, M. canadense, M. dispar, M. bovirhinis, strains of Group 7 according to Leach, strain ST 6, and ureaplasma strains. In the GDR, enzootic mastitis has been confined to A. laidlawii and A. axanthum.  相似文献   

15.
Identification of Mycoplasmatales in pneumonic calf lungs   总被引：3，自引：0，他引：3  
Lungs from 153 calves with clinical signs of pneumonia were examined post-mortem (PM) for the presence of mycoplasmas and ureaplasmas during a 38-month period. Sixty-two percent of the cases were submitted during the months when wide fluctuations in climatic conditions occur. Using indirect fluorescent antibody tests (IFAT) and culture, mycoplasmas and/or ureaplasmas were detected in 63% of the lungs examined. Mycoplasma dispar was detected in 39%, M. bovis in 36%, Ureaplasma spp. in 22% and M. bovirhinis in 8.5% of the lungs. Thirty percent of the lungs were infected with more than one species; the most frequent combination was M. bovis, M. dispar and Ureaplasma spp. (10.5%). M. arginini, M. bovigenitalium and acholeplasmas were not cultured. M. dispar was shown to remain viable for up to 15 days PM in apical and cardiac lobes held at 4 degrees C and also was detected by IFAT in the same tissues for 49 days.  相似文献   

16.
A comparison of the persistence of mycoplasmas in animals was carried out. When inoculated into liquid media, strains of Mycoplasma bovis, M. arginini, Acholeplasma laidlawii, and A. axanthum persisted for 59-185 days post-inoculation. The survival periods were not significantly influenced by temperature (4, 30, 37 degrees C, and room temperature). The survival periods for M. bovigenitalium, M. gallisepticum, M. bovirhinis, and M. gateae ranged from <7 to 185 days depending on medium components and temperature. Further, it was determined that strains of M. bovigenitalium, M. bovis, M. bovirhinis, M. arginini, and A. laidlawii persisted in a dry paper disc for at most 28, 126, 154, 56 and over >168 days at 4 degrees C, respectively. At 4 degrees C, strains of M. gallisepticum, M. columborale, M. edwardii, M. felis, and M. gateae survived for at most 28, 21, 42, 28, 28 and 70 days, respectively. At 30 degrees C, strains of M. bovis, M. bovirhinis, M. arginini, A. laidlawii, and M. gallisepticum persisted for at most 28, 84, 56, >168 and 14 days, respectively, but strains of M. gallisepticum, M. columborale, M. edwardii, M. felis, M. gateae, and U. diversum did not survive for more than 14 days. In an outdoor environment, strains of M. bovirhinis and A. laidlawii survived for at most 28 and 14 days, respectively. Finally, it was found that 14 isolates of M. gallisepticum persisted for periods similar to those of the reference strains. The results under dry conditions at a variety of temperatures presented contribute to understanding the epizootiology of mycoplasmal infections in the field.  相似文献   

17.
The purpose of this study was to 1) estimate the herd prevalence of contagious mastitis pathogens in bulk milk from Prince Edward Island (PEI) dairy farms, 2) determine the association between bulk milk culture results and mean bulk milk somatic cell count (BMSCC), and 3) investigate the agreement of repeated bulk milk cultures. Three consecutive bulk milk samples were obtained at weekly intervals from all 258 PEI dairy herds and were cultured using routine laboratory methods. Cumulative prevalence of Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma spp. (M. bovis and M. alkalescens) was 74%, 1.6%, and 1.9%, respectively. Bulk milk somatic cell count of Staph. aureus-positive herds was higher than that of negative herds. Agreement for Staph. aureus isolation between 3 consecutive tests was moderate (kappa = 0.46). Mycoplasma bovis and M. alkalescens in bulk milk are being reported for the 1st time in PEI ever and in Canada since 1972.  相似文献   

18.
The nasal mycoplasmal flora of healthy calves and cows.   总被引：1，自引：0，他引：1  
The nasal mycoplasmal flora of 270 healthy cows from 27 herds in the Netherlands and 35 healthy calves from 7 of these herds was examined. Various methods for isolating mycoplasmas were compared. The prevalence of the various species was as follows: Ureaplasma diversum in 3 (9%) calves; Mycoplasma dispar in 14 (40%) calves; M. bovis in 1 (3%) calf; M. bovirhinis in 23 (66%) calves and 16 (6%) cows; M. bovoculi in 8 (23%) calves and 53 (20%) cows; M. canis in 1 (3%) calf; M. equirhinis in 2 (1%) cows; M. conjunctivae in 2 (1%) cows; Acholeplasma laidlawii in 1 (3%) calf and 3 (1%) cows; and A. axanthum in 7 (3%) cows. The noses of healthy calves were less frequently colonized by the pathogenic species U. diversum and contained fewer U. diversum and M. dispar organisms than the noses of pneumonic calves. We concluded that the mycoplasmal flora of calves and healthy cows was quite different and also that cows play only a minor role in the epidemiology of pathogenic mycoplasma species of calves in the Netherlands.  相似文献   

19.
Mycoplasma bovis is known to be responsible for pneumonia and arthritis in calves, as well as mastitis in dairy cows. Despite clear evidence of its pathogenic potential, little is known about mechanisms of cytadherence and the molecular factors involved. The purpose of this work was to compare adherence rates of M. bovis field strains to different host cell lines and study the effects of cloning and sub-culturing M. bovis strains on their adherence properties. Eighteen metabolically labeled M. bovis strains isolated from different pathological backgrounds were examined in adherence trials using four different host cell lines, i.e. embryonic bovine lung (EBL), embryonic bovine trachea (EBTr), Madin Darby bovine kidney (MDBK) and rabbit kidney (RK) cells. Although large interstrain variations in adherence rates (3.4-19.1%) were measured they could not be correlated to the pathological background (pneumonia, arthritis or mastitis). Adherence rates to the fibroblast cell line (EBTr) were significantly lower than those to the three epithelial cell lines (EBL, MDBK and RK). The only non-pathogenic strain (221/89) exhibited lower adherence rates than three isolates from clinical mastitis. Interestingly, adherence rates were significantly reduced after in vitro passaging. In contrast, no effect of single cloning of strains on adherence was observed. There was no general correlation between expression of variable surface proteins (Vsps) as monitored by immunoblotting and adherence rates, although alterations in Vsp expression profiles were seen as a consequence of passaging. As there is probably a large number of adhesins, variable and non-variable, on the surface of M. bovis cells the issue is very complex, and the most active components have yet to be identified.  相似文献   

20.
In studies to determine whether there were antigenic differences between strains (isolates) of Moraxella bovis, the sera from vaccinated calves were tested with isolates of M bovis while the calves were experiencing epizootics of infectious bovine keratoconjunctivitis (IBK). Before the epizootics of IBK, the calves were intramuscularly vaccinated with a formalin-killed autogenous M bovis bacterin. During the epizootics, the eyes were examined by cultural technique, and isolates which were obtained were categorized by catalase activity, source (diseased or nondiseased eyes), and reactivity with the various sera. The serum reactivity of the isolates was compared with that of the vaccinal strain. The vaccinal strain and 8 of the 1 5 selected isolates obtained during the 1974 epizootic were catalase negative. Seven of the 15 isolates from the 1974 epizootic and all of the selected isolates from the 1975 epizootic were catalase positive. A significantly higher (P less than 0.01) percentage of calf sera were serologically reactive with the vaccinal strain and other catalase-negative isolates (45.0%) than with catalase-positive isolates (34.8%). The results, although not definitive, suggest that there may be antigenic differences among strains of M bovis. These differences should be considered when cattle are vaccinated against IBK under natural conditions of exposure.  相似文献   

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