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1.
Mycoplasmal bovine mastitis is potentially a highly contagious disease that can cause severe economic problems in affected herds. The purchase of replacement heifers and cows are frequently the origin of mycoplasmal mastitis outbreaks in previously Mycoplasma-free herds. Purchased cows and heifers should be quarantined and tested for mycoplasmal mastitis before admission to the regular herd. Detection of Mycoplasma-infected cows by culture of milk is straightforward, although there are problems of sensitivity for its detection in milk samples that are inherent to the nature of the disease and laboratory procedures. After detection of infected cows, the best way to protect the herd is to culture all cows in the herd, cows with clinical mastitis, and all heifers and cows after calving and before entering the milking herd. Control of mycoplasmal mastitis requires test and culling from the herd of Mycoplasma-positive cows if possible. When a large number of cows are infected, strict segregation with adequate management is an option; however, animals in this group should never re-enter the Mycoplama-free herd. The functioning of the milking equipment and milking procedures should be evaluated carefully and any flaws corrected. There is no treatment for mycoplasmal mastitis, and vaccination has not proven to be efficacious to prevent, decrease the incidence, or ameliorate the clinical signs of mycoplasmal mastitis. Waste milk should not be fed to calves without pasteurization. M bovis may cause several other pathologies in animals of different ages on a farm, including pneumonia, arthritis, and ear infections. The survival of mycoplasmas in different farm microenvironments needs to be further investigated for its impact on the epidemiology of the disease.  相似文献   

2.
Enzootic mycoplasmal mastitis in a large dairy during an eight-year period   总被引：1，自引：0，他引：1  
During an 8-year period, a study was conducted in a large dairy in the Sacramento Valley of California, to define factors associated with the introduction and spread of mycoplasmal mastitis. To identify cows in which mycoplasmal infection appeared in 22 of 25 (88%) periods of new infection, milk samples were collected weekly from freshened cows and from hospitalized cows with clinical mastitis. The disease first appeared in freshened cows in at least 36% of the periods of new cases of mycoplasmal mastitis, which indicated that special attention must be paid to freshening cows in an attempt to control spread of the disease. New cases of mycoplasmal mastitis were recorded more often in January through April than during the rest of the year. Rates of mastitis infection caused by other pathogens (contagious and environmental organisms) increased during months when new cases of mycoplasmal mastitis were recorded. Sanitation on the farm during udder infusion and milking was a major factor in controlling the introduction and spread of mycoplasmal mastitis.  相似文献   

3.
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   

4.
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   

5.
The California Dairy Herd Improvement Association records of 29 California dairies which experienced clinical mycoplasmal mastitis between January 1975 and December 1977 were examined and compared to the records of selected control herds. A 15-fold greater risk of clinical mycoplasmal mastitis was found among large herds as compared to small herds. On average, herds with clinical mycoplasmal mastitis culled 5 % more cows than did control herds (33 % vs 28 %). No difference was found in average milk production. These findings compare closely with the findings of a previous report where infected herds were identified by the presence of pathogenic mycoplasma in bulk tank milk. The similarity of results support the use of frequent bacteriologic culture of bulk tank milk as a routine surveillance strategy for mycoplasmal mastitis in endemic areas. The similarity of results also supports the use of routine clinical diagnostic data in the study of the epidemiology of diseases of veterinary importance.  相似文献   

6.
Mycoplasmas are an important and economically significant cause of mastitis in dairy cows in various parts of the world. The organisms are highly contagious, with the main reservoir of infection originating from cows with subclinical mastitis. In 1998 the 1st cases of bovine mastitis due to Mycoplasma bovis were diagnosed in Ardabil State, Iran. An investigation was carried out with the aim of establishing the extent of mycoplasma infections in dairy cows in Ardabil State. Milk samples obtained from 80 cows with clinical mastitis were cultured in the laboratory for the presence of mycoplasmas. Similarly, 48 bulk-tank milk samples were examined for the presence of mycoplasmas. A modified Hayflick broth was used to isolate the mycoplasmas and an immunoperoxidase test used for the species identification of the isolates. Mycoplasma bovis was isolated from 39 (48.75%) of the clinical mastitis samples and from 48 of the bulk-tank milk samples tested. This indicated that mycoplasma udder infections were more prevalent in dairy cows in Ardabil State than previously thought.  相似文献   

7.
Detection of the antibodies to the species Mycoplasma bovis in the serum and milk of dairy cows coming from a mastitis-infected herd is a good example of utilization of the ELISA immunoenzymologic method in the mycoplasmology. Examining the samples from 75 dairy cows and applying the indirect hemagglutination test, good correlation of the results of the two tests was determined. The antibodies to the species Ureaplasma diversum were demonstrated by the ELISA method both in the bovine serum and in the milk of dairy cows infected slightly with mastitis. We chosen that strain which detected the maximum titres in the selected samples of the sera out of four antigens prepared from various strains of U. diversum. Rabbit sera hyperimmune to 26 strains of the mycoplasmas of various species were used to identify two antigens (after removing the antibodies to the components of the media). Specific reaction was obtained with the antisera to M. hyorhinis and M. arginini.  相似文献   

8.
Milk and faeces samples from cows with clinical symptoms of paratuberculosis were examined for the presence of Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) by culture and PCR. M. paratuberculosis was cultivated in variable numbers from faeces or intestinal mucosa in eight of 11 animals. In milk from five cows (all faeces culture positive), we cultivated a few colonies of M. paratuberculosis (<100 CFU per ml). Milk samples from two cows were PCR positive (both animals were faeces culture positive, and one cow was milk culture positive). One cow was culture negative on intestinal mucosa, but culture positive in milk, and two cows were negative in culture and PCR from both faeces and milk. In conclusion, the presence of M. paratuberculosis could be detected in raw milk by PCR, but cultivation of milk was more sensitive.  相似文献   

9.
Mycoplasma bovis (M. bovis) is a highly infectious pathogen of cattle causing pneumonia, polyarthritis, otitis, and less frequently, subcutaneous abscesses, abortions and meningitis. Ineffective drugs treatments, culling of infected cows and loss of milk production can lead to significant economic loss on dairy farms. The early detection of cows excreting M. bovis bacteria to prevent mastitis outbreaks is warranted. Reports suggest that the risk of M. bovis mastitis is higher in larger dairy herds. The objective of this study is to estimate the herd-level prevalence of M. bovis in Flanders, Belgium by culturing bulk tank milk samples taken from dairy farms. Three bulk tank milk samples per dairy herd were taken over four weeks, with collection intervals of two weeks. Culturing was done after pre-incubation using modified Hayflicks media to increase the chances of recovery of bacteria. For the identification of M. bovis, tDNA intergenic spacer PCR was used. In three herds (1.5%) of the 200 herds sampled, M. bovis was isolated from one of the three consecutive bulk tank milk samples. We conclude that in Flanders in 2009 at least 1.5% of the dairy herds had one or more cows excreting M. bovis in the milk. The frequent monitoring of bulk tank milk to detect the presence of M. bovis, especially in expanding herds on farms that often purchase replacement animals, should be encouraged in order to detect the presence of M. bovis and to monitor the success of control procedures following an outbreak of mycoplasmal mastitis in the herd.  相似文献   

10.
A highly sensitive and specific PCR (MB-PCR) was used in preliminary studies to detect M. bovis in milk samples to investigate its association with high somatic cell count (SCC), an indicator of subclinical mastitis and one of the factors in down grading the quality of milk. A total of 186 and 167 herds were tested with 43% and 62% of herds positive for M. bovis in Victoria and North Queensland, respectively. The quarter milks from 52 cows with persistently high SCC were tested by MB-PCR and culture to investigate the association of M. bovis with major mastitis pathogens (MMP). M. Bovis was detected in 77% of cows of which 19% alone had M. bovis without any other bacteria, 17% had M. bovis in combination with major mastitis pathogens and 40% had M. bovis in combination with non-major mastitis pathogens. We believe that M. bovis is widespread in dairy cattle and has the potential to produce disease alone or to predispose the udder to disease caused by major mastitis and environmental pathogens. These studies have revealed a hitherto unrecognised high prevalence of M. bovis in dairy cattle in North Queensland and Victoria in Australia. These initial studies also give a clear association between M. bovis and elevated somatic cell counts.  相似文献   

11.
A polymerase chain reaction (PCR) test was compared with culture for the detection and diagnosis of bovine Mycoplasma intramammary infection. The PCR test was applied to 24-hour Mycoplasma enrichment cultures of milk from cows with suspected mastitis and from bulk tank milk. In comparison to culture, the sensitivity and specificity of the PCR method were 96.2% and 99.1% for individual cow milk and 100% and 99.8% for the bulk tank milk, respectively. However, in discrepant cases where PCR was positive and culture was negative, the PCR test was correct; subsequent PCR tests and culturing of the individual cow's milk yielded positive results. The PCR test simultaneously detected and differentiated among 11 bovine Mycoplasma species.  相似文献   

12.
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13.
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   

14.
A cross-sectional study was carried out on 200 randomly selected farms in each of the Iringa and Tanga regions of Tanzania to estimate the prevalence and risk factors for subclinical mastitis in dairy cows kept by smallholders. Subclinical mastitis was assessed using the California mastitis test (cmt), and by the bacteriological culture of 1500 milk samples collected from 434 clinically normal cows. The percentages of the cows (and quarters) with subclinical mastitis were 75.9 per cent (46.2 per cent) when assessed by the cmt and 43.8 per cent (24.3 per cent) when assessed by culture. Factors significantly associated with an increased risk of a cmt-positive quarter were Boran breed (odds radio [or]=3.51), a brought-in cow (rather than homebred) (or=2.39), peak milk yield, and age. The stripping method of hand milking was associated with a significantly lower prevalence of cmt-positive quarters (or=0.51). The cmt-positive cows were more likely to be culture positive (or=4.51), as were brought-in (or=2.10) and older cows.  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.
Mycoplasma bovigenitalium was isolated from milk samples from 16 of 99 cows on one farm during a 15-week period in the summer of 1986. One cow was severely affected, four cows had relatively mild signs of mastitis, and three had only altered dry-cow udder secretions. Eleven of the infected cows were dry and three had been calved less than 48 hours. The abrupt method of drying-off and improvements in cleaning of the milking equipment were introduced, but no other control measures were instituted to eradicate the mycoplasma infections. After this mild outbreak of mastitis the herd was monitored for the next 17 months. In total 19 cows had a mycoplasma isolated from udder secretions. Acholeplasmas were isolated from 14 cows but were not associated with clinical mastitis. The udder infections with mycoplasmas apparently resolved without resorting to the segregation and culling of infected animals.  相似文献   

17.
CASE DESCRIPTION: 9 first-lactation dairy cows in a closed dairy herd had swelling in the forelimbs and forelimb lameness. Mycoplasmal arthritis and mastitis were diagnosed. CLINICAL FINDINGS: Swelling of the carpal joint, diffuse subcutaneous edema from the carpal to metacarpophalangeal joints, and forelimb lameness were evident in 9 first-lactation cows 7 to 21 days after parturition. Diagnostic testing revealed that 3 of 3 bulk-tank milk samples, 3 milk samples from cows with clinical mastitis, 2 fluid samples obtained from arthritic joints, and samples from the lungs and spleen of a cow that had died yielded positive results for Mycoplasma spp. Nucleic acid sequence analysis performed by use of a PCR assay on the joint fluid and lung tissues confirmed infection with Mycoplasma bovis. TREATMENT AND OUTCOME: Affected cows were treated by IM administration of flunixin meglumine and dexamethasone for 3 days. All cows were nonresponsive to treatment (3 cows died, and the other 6 were culled). Follow-up culture for Mycoplasma spp of milk samples from the bulk tank and from all lactating cows was recommended to screen for chronic subclinical carriers. CLINICAL RELEVANCE: Mycoplasmal infections may cause unusual initial clinical signs or an atypical history. When dairy cattle, including those residing in closed herds, have lameness, swelling of the carpal or metacarpophalangeal joints, edema of the distal portions of the forelimbs, or polyarthritis, infection with Mycoplasma spp should be investigated. Delay in diagnosis of mycoplasmal infections in dairy herds can result in substantial financial loss and the establishment of chronic subclinical carriers.  相似文献   

18.
Six cows were inoculated into the mammary gland with eight mycoplasma strains isolated from the genital tract of bulls and two type strains. The milk of cows infected with Mycoplasma bovigenitalium strains isolated from the genital tracts of bulls showed a change in the appearance and contained large quantities of mycoplasmas and specific antibodies. The mastitis was most intense in about 9 days and began to subside in 17 days infection. The type strain of M. bovigenitalium PG11 failed to produce mastitis. On the other hand, the type strain of M. bovis PG45 produced severe mastitis after a 14-day latency period, with the infection spreading to the uninoculated quarters, causing atrophy of the mammary gland, and persisting till slaughter. The sera of all cows that developed mastitis after experimental infection contained high titres of specific antibodies. The two infecting mycoplasma species were recovered from the inner organs and mammary glands of these cows after slaughter.  相似文献   

19.
Mycoplasma bovis was detected in 18/219 (8.2%) quarter milk samples collected from cases of bovine clinical mastitis in Northern Greece between November 1997 and March 1999. The cases occurred in 2/37 (5.4%) of the herds examined. The micro-organism was isolated from bulk milk samples (BTS) from the two positive herds but was not isolated from 111 composite milk samples collected from clinically healthy cows from all 37 herds. Isolates were identified as M. bovis by polymerase chain reaction (PCR) assay. Other micro-organisms were also isolated from the M. bovis positive samples. The M. bovis-positive cows had all been imported into Greece from other European countries.  相似文献   

20.
In October 1985, mycoplasmas were isolated from bulk tank milk samples in a large Florida dairy (greater than 1,400 lactating cows). At that time, measures to isolate and control the spread of infection were instituted. In an initial screening test, Mycoplasma bovis was isolated from 21 of 153 milking string samples (milk from all quarters of 10 cows/string). Composite quarter milk samples from all quarters of every individual lactating cow in the herd were obtained for culture in November 1985 and December 1985. In October, 88 of 1,535 (5.7%) cows were identified as Mycoplasma-positive. An additional 31 Mycoplasma-infected cows were identified in December. The dairy elected to maintain the infected cows in a separate Mycoplasma-positive subherd, which would be milked at the end of each milking session. Seven additional Mycoplasma-positive cows were identified at initiation of lactation. All newly identified infected cows were transferred to the Mycoplasma-positive subherd. After segregation of Mycoplasma-positive cows, bulk tank milk samples obtained routinely from the main herd remained culture negative throughout the study. From February 1986 to October 1986, quarter milk samples were obtained monthly from cows in the Mycoplasma-positive subherd. Any cow that developed clinical mastitis or substantial decrease in milk production was, at the discretion of the herdsman, culled. Of the 126 cows in the subherd, 22 (17.5%) were culled for mastitis, 35 (27.8%) were culled for low production, and 9 (7.1%) were culled for other reasons. Of the remaining 60 cows, 16 (12.7% of the 126 cows) were Mycoplasma-positive on the basis of results from one or more samples obtained after February 1986.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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