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1.
Y H Schukken D Van de Geer F J Grommers J A Smit A Brand 《The Veterinary record》1989,125(15):393-396
Ten herds with low somatic cell counts in bulk milk had an incidence of clinical mastitis of only 2.2 per 100 cows whereas 10 other herds with similarly low cell counts had an incidence of 53.6 per 100 cows. The major pathogens in the herds with a high incidence were Escherichia coli, Streptococcus uberis, Staphylococcus aureus and the coagulase-negative staphylococci. The percentage of uninfected quarters in the herds with a high incidence of clinical mastitis was 21.4 per cent compared with 12.2 per cent in the herds with a low incidence of clinical mastitis. The prevalence of coagulase-negative staphylococci, Corynebacterium bovis and Micrococcus species was higher in the herds with a low incidence of clinical mastitis. There was a significant linear relationship between the percentage of uninfected quarters and the incidence of clinical mastitis in the herds with a high incidence of clinical mastitis. In herds with a low incidence of clinical mastitis significantly less teat disinfection after milking was practised. The results suggest that infections with minor pathogens tend to protect cows against mastitis, and that teat disinfection after milking may increase the percentage of uninfected quarters and lead to an increased risk of clinical mastitis in herds with low somatic cell counts in bulk milk. 相似文献
2.
A survey of clinical and subclinical mastitis was carried out on 97 dairy farms in England and Wales, selected at random from members of a national milk recording scheme. The farmers were asked to collect aseptic milk samples from five consecutive cases of clinical mastitis and from five quarters with high somatic cell counts using a defined protocol, and they completed a questionnaire that included information on the cows sampled, the herd and the history of mastitis in the herd. The samples were collected throughout the year. The mean incidence of clinical mastitis was 47 cases per 100 cows per year (estimated from historic farm records) and 71 cases per 100 cows per year (estimated from the samples collected). Streptococcus uberis and Escherichia coli were isolated in pure culture from 23.5 per cent and 19.8 per cent, respectively, of the clinical samples; 26.5 per cent of the clinical samples produced no growth. The most common isolates from the samples with high cell counts were coagulase-negative staphylococci (15 per cent), S uberis (14 per cent) and Corynebacterium species (10 per cent). Staphylococcus aureus and coagulase-positive staphylococci together accounted for 10 per cent of the samples with high somatic cell counts; 39 per cent produced no bacterial growth. 相似文献
3.
Green MJ Green LE Bradley AJ Burton PR Schukken YH Medley GF 《The Veterinary record》2005,156(3):71-77
To assess the prevalence and patterns of bacterial isolates, cultures were made from the dry mammary glands of dairy cows in six commercial dairy herds in the UK. Milk samples were taken from all four quarters of 480 cows at drying off and at weekly intervals from 14 days before to seven days after calving. A major mastitis pathogen was isolated from at least one quarter of 220 (45.8 per cent) of the cows and from more than one quarter of 90 (18.8 per cent) of them. During the late dry to calving period, of the 957 quarters with three culture results, a major mastitis pathogen was cultured from 236 (24.7 per cent) quarters of 186 (38.8 [corrected] per cent) cows. The most commonly isolated major pathogen was Escherichia coli, followed by Streptococcus uberis and coagulase-positive staphylococci. There were significant differences between the patterns of isolates from different farms and in different calving months, suggesting that the rate of infection was partially dependent on external conditions. The isolation of E. coli, S. uberis or coagulase-positive staphylococci from a cow during the late dry/periparturient period was associated with an increased risk of that cow being culled in the next lactation. Bayesian general linear mixed models were used to assess the associations between the different bacterial species. The probability of isolating either E. coli or S. uberis was significantly greater when the other organism was cultured in a milk sample; this was also true of coagulase-positive staphylococci and S. uberis. When Corynebacterium species were isolated from a milk sample, the probability of isolating coagulase-positive staphylococci or S. uberis decreased significantly, and when coagulase-negative staphylococci were isolated the probability of isolating coagulase-positive staphylococci was reduced. 相似文献
4.
The bacterial causes of subclinical mastitis were determined in samples of milk taken from one half of the udders of 159 goats in three different herds. The mean prevalence of subclinical infection was 33 percent, with prevalences of 26 percent, 39 percent and 42 percent in the three herds. Staphylococcus aureus was isolated from seven (13 percent) of the 53 infected halves, coagulase-negative staphylococci accounted for 47 percent, Corynebacterium species for 31 percent and alpha-haemolytic streptococci for 6 percent of the infected samples. The mean somatic cell count of the uninfected milk samples was 428,000 cells/ml, and 93 percent of uninfected samples had counts less than 1,000,000 cells/ml; the mean cell count of the infected samples was 2,785,000 cells/ml. 相似文献
5.
W D Hueston N R Hartwig J K Judy 《Journal of the American Veterinary Medical Association》1986,188(5):522-524
The overall sensitivity of the California mastitis test (CMT) for detecting intramammary infection (the likelihood of a positive CMT score in the presence of intramammary infection) was 69.3%. The specificity of the CMT (likelihood of a negative test in the absence of intramammary infection) was 76.5%. When only infections by major ovine mastitis pathogens were considered, the sensitivity increased to 100% and the specificity decreased to 71.1%. Bacterial cultural examination and CMT scores were recorded for 526 samples of milk obtained from 106 brood ewes. Positive CMT scores were recorded for all samples from udder halves infected with major ovine mastitis pathogens (coagulase-positive staphylococci, Escherichia coli, and Pasteurella haemolytica). The CMT scores for samples from udder halves infected with coagulase-negative staphylococci were variable. 相似文献
6.
This study was carried out to determine the prevalence of coagulase-negative staphylococci in clinical and subclinical mastitis in commercial and small-scale farms in Zimbabwe. Thirty five quarter milk samples from clinical mastitis cases and 371 quarter milk samples from cows with subclinical mastitis were cultured for bacterial pathogens. The most frequent pathogens isolated in clinical mastitis were the enteric bacteria (31.4%), followed by coagulase negative staphylococci (22.9%) and then Staphylococcus aureus (17.1%), whereas in subclinical mastitis S. aureus (34.2%) and coagulase-negative staphylococci were (33.2%) the most common. Bacillus species were only isolated in milk samples from subclinical mastitis. Coagulase-negative staphylococci were observed in mixed infections with other bacteria in only 2.2 of the 406 milk samples from clinical and subclinical mastitis where they were isolated together with Bacillus species in 6 of the 9 mixed infection cases. About 95% of the milk samples from which 131 coagulase-negative staphylococci were isolated had correspondingly high somatic cell counts. The coagulase-negative staphylococci isolated most frequently were S. chromogenes (7.9%), S. epidermidis (7.4%) and S. hominis (5.9%). They were all associated with high somatic cell counts. All the coagulase-negative staphylococci isolates were susceptible to cloxacillin and erythromycin, and more than 90% of the isolates were susceptible to neomycin, penicillin and streptomycin. The highest resistance was to tetracycline (17.6%), followed by lincomycin (13.7%). About 8% of the isolates were resistant to both penicillin and streptomycin. 相似文献
7.
Somatic cell counts, the bacteriological condition of the milk and antibodies against caprine arthritis encephalitis virus (CAEV) were measured monthly throughout lactation in 121 lactating goats of the Murcia-Granada breed in four commercial dairy goat herds. The prevalence of bacterial intramammary infection was 5.6 per cent and the prevalence of CAEV infection was 20.6 per cent. An analysis of variance revealed a significant effect of herd, intramammary infection and the interaction between intramammary infection and CAEV on the somatic cell count. In udder halves free of intramammary infection, the somatic cell counts were significantly lower in seronegative goats than in seropositive goats (P<0.05), but the difference was not significant in udder halves persistently infected by bacteria. There was a significant increase in somatic cell counts due to bacterial intramammary infection (P<0.01) in the seronegative goats, but this effect was not present in the seropositive animals. 相似文献
8.
The germ levels of 2,182 milk samples obtained from udder quarters with subclinical mastitis were compared to milk sampled from 2,061 udder quarters with physiological cell counts or conductivity values. Three cattle herds were involved in the test programme. No germ growth was established from 9.5 per cent of all samples taken from udder quarters with increased cell counts and conductivities and from 4.1 per cent of those samples taken from intact udder quarters. Samples taken from udder quarters with subclinical mastitis exhibited the following rises in bacteria, as compared to samples from intact quarters: staphylococci by 3.1 per cent, staphylocci in germ mixtures by 3.0 per cent, CAMP-positive streptococci by 2.2 per cent, alpha-haemolytic CAMP-negative streptococci by 0.8 per cent, anhaemolytic streptococci in germ mixtures by 0.4 per cent, beta-haemolytic streptococci by 0.5 per cent, and Pseudomonas aeruginosa by 1.4 per cent. Other germ species and mixtures exhibited declining trends along with growing subclinical affection of udder quarters. All findings so far obtained in the presence of subclinical mastitis are likely to suggest that 11.4 per cent of detected bacteria were of pathogenicity to udders. However, attempts to localise those 11.4 per cent were unsuccessful, since no significant difference could be calculated by comparison of intact with affected udder quarters. Reference is made in the discussion to primary and secondary germ levels of milk samples and their relevance to the problem and its elucidation. 相似文献
9.
Six hundred and thirty clinically-normal milk samples from dairy goat flocks comprising a mixed population of German Alpine, Toggenburg, Saanen and Galla crosses were examined over a 3-month period to determine the prevalence of bacterial organisms. Bacteria were isolated in 28.7% of the milk samples (181/630) either singly (92.8%) or in combination (7.2%). The most prevalent bacterial organisms were Staphylococcus spp. (60.3%), followed by Micrococcus spp. (17.7%), Acinetobacter spp. (5%), Actinomyces spp. (5%) and Streptococcus spp. (1.1%). The Staphylococcus spp. were mainly coagulase negative (64.3%). Coagulase-negative staphylococci and coagulase-positive staphylococci accounted for 37.5% and 22.7% respectively of the total bacteria isolated. The isolation of bacteria, some of which are important in clinical and subclinical mastitis, in apparently normal caprine milk, indicates that particular attention should be given to the management of these dairy goat flocks in order to avoid the development of cases of clinical mastitis. 相似文献
10.
R N González D E Jasper T B Farver R B Bushnell C E Franti 《Journal of the American Veterinary Medical Association》1988,193(3):323-328
The California mastitis test (CMT) and bacteriologic culture were performed on samples of bulk-tank milk and cow-composite milk (n = 23,138 cows) from 50 California dairies, 19 of the 50 with known mastitis problems. Thirty-eight (76.0%) bulk-tank milk samples and 12,334 (53.3%) cows were positive by results of the CMT. Potential mastitis agents were isolated from 5,085 (22%) cows. Staphylococcus aureus was isolated from all 50 herds, Streptococcus agalactiae was isolated from 47 herds, and Mycoplasma sp was isolated from 24 herds. For cow-composite milk samples, the prevalences were 9.3% for Str agalactiae, 9.1% for S aureus, 0.9% for Mycoplasma sp, 1.2% for coliform bacteria, 0.9% for other streptococci, 0.8% for coagulase-negative staphylococci, and 1.3% for other organisms. The relative sensitivity and the relative specificity of the CMT performed on cow-composite milk samples were 83.4% and 55.2%, respectively, and the predictive value of positive CMT results was 34.2%. 相似文献
11.
Progress in controlling mastitis in England and Wales 总被引：1，自引：0，他引：1
J M Booth 《The Veterinary record》1988,122(13):299-302
Mastitis in England and Wales has been controlled over the past 20 years while the average size of dairy herds has doubled to 65 cows. The incidence of clinical mastitis has been reduced from approximately 120 to 150 cases per 100 cows to less than 50 cases. The limited data on the prevalence of subclinical mastitis indicate that it has been reduced from over 50 per cent of cows infected to less than half this level. The application of the major mastitis control measures on the farm has doubled over the period 1973 to 1983 and had reached 66 to 90 per cent for individual measures by 1983. The national mean cell count in milk has been reduced from 573,000 to 352,000 cells/ml between 1971 and 1986, and the proportion of herds having annual mean cell counts below 300,000 cells/ml has increased from 15.7 per cent to 40.7 per cent in the last eight years. 相似文献
12.
Gianneechini R Concha C Rivero R Delucci I Moreno López J 《Acta veterinaria Scandinavica》2002,43(4):221-230
Twenty-nine dairy farms were selected to determine the incidence of clinical mastitis, prevalence of sub-clinical mastitis and bacterial aetiology in the West Littoral Region of Uruguay. In samples taken by the owner and frozen at -20 degrees C during a week the incidence rate of clinical mastitis was determined as 1.2 cases per 100 cow-months at risk. Staphylococcus aureus was the most common isolated pathogen in 37.5% of 40 milk samples from clinical cases obtained in 1 month. No bacteria grew in the 32.5% of the total samples. A sub-sample including 1077 dairy cows from randomly selected farms was used to determine the prevalence of sub-clinical mastitis. These samples were taken on one visit to each farm. The prevalence was 52.4% on a cow basis and 26.7% on an udder quarter basis. In 55.1% of the quarters of the selected animals with more than 300,000 cells/ml there was no growth. The isolated pathogens from sub-clinical cases and their relative frequencies were: Staphylococcus aureus 62.8%, Streptococcus agalactiae 11.3%, Enterococcus sp. 8%, coagulase-negative staphylococci 7.4%, Streptococus uberis 6.4%, Streptococcus dysgalactiae 1.8%, Escherichia coli 1.5% and Staphylococcus hyicus coagulase-positive 0.6%. 相似文献
13.
Extract Sir:- Immunisation with staphylococcal vaccines is a potential means of increasing the resistance to bacterial invasion of the udder. However, the development of an effective vaccine for control of staphylococcal mastitis in ruminants has proved to be an elusive goal. There have been numerous attempts to develop vaccines against coagulase-positive Staphylococcus aureus mastitis, but very few attempts to develop vaccines using coagulase-negative staphylococci. Development of a vaccine against coagulase-negative staphylococci may help control the sub-clinical mastitis caused by these organisms and assist in the search for an effective vaccine against mastitis caused by the more pathogenic coagulase-positive S. aureus.We describe here an experiment in which ewes were immunised with live coagulase-negative staphylococcal vaccine and challenged during lactation by intramammary infusion of a homologous strain. 相似文献
14.
A series of least-squares analytical models were developed in a cross-sectional epidemiologic study of the observed variability in within-herd high somatic cell count (SCC) prevalence, a measure of mastitis prevalence in dairy herds. The dependent variable, high SCC prevalence, was calculated as the 12-month rolling herd average percentage of lactating cows with milk SCC in excess of 283 000 cells ml−1.
The first analysis involved the results of a bacteriologic survey of bulk-tank milk samples for the presence of Streptococcus agalactiae and coagulase-positive staphylococci, the two most common contagious intramammary pathogens. The presence of either pathogen in bulk-tank samples was associated with significantly higher high SCC prevalence.
The second analysis involved responses to a questionnaire concerning management and mastitis control practices. Both the practices of post-milking teat dopping and dry-cow antibiotic therapy were associated with significantly lower high SCC prevalence.
The third analysis combined the data collected for the first two analyses so that the independent variables included both bulk-tank bacteriologic results and management and mastitis control practices. This model was able to explain a greater proportion of the variability in high SCC prevalence than either of the other two models. There were three variables associated with significant decreases in high SCC prevalence namely the absence of Streptococcus agalactiae in the bulk tank milk, the adoption of post-milking teat dipping and the practice of dry-cow antibiotic therapy of all cows.
Milk somatic cell counting is now widely accepted and practiced in many countries, and individual-cow SCC data are available from large numbers of herds at a minimal expense. By corroborating the role of post-milking teat dipping and dry-cow antibiotic therapy in mastitis control programs, this study establishes the usefulness of high SCC prevalence data for epidemiologic studies of mastitis control practices. 相似文献
15.
M C Smith M Roguinsky 《Journal of the American Veterinary Medical Association》1977,171(12):1241-1248
Udder problems of modern dairy goats are similar to those seen in dairy cows. Anomalies of the goat's udder and teats are common, and many may be hereditary. Skin diseases of the udder include viral infections, mange, sunburn, wounds, and staphylococcal dermatitis. There are numerous known causes of caprine mastitis. These include streptococci, hemolytic and nonhemolytic staphylococci, corynebacteria, and mycoplasmas. Diagnosis of mastitis in goats is often difficult, as the udder secretion may remain grossly normal and somatic cell counts in nonmastitic goats are higher than the recognized normal range for cows. The importance of nonhemolytic staphylococcal cultures remains uncertain. Nonhemolytic staphylococci were isolated at the New York State Mastitis Laboratory from 30% of normal halves and from 22% of halves of udders from goats with assorted clinical problems. Treatment and prophylaxis of caprine mastitis closely parallel the standard technique recommended for bovine mastitis. 相似文献
16.
The results of a mastitis control programme operated in south west England for three years are given. Farmers participating in the full mastitis control group agreed to treat each cow at drying off with 500 mg benzathine cloxacillin in each quarter, to have their milking machines tested and to correct any faults, and to practise teat dipping. Data covering cell counts, milk production, milk quality and clinical mastitis, were assessed from herds taking part in the programme. Cell counts were analysed from all 507 herds taking part in the programme. Milk production records for the full mastitis control group (188 herds) over a three year period are discussed, and these results compared with milk production figures from Milk Marketing Board records from herds in the south west of England which were carrying out no specific mastitis control programme. The milk quality data compare the findings in 159 herds in the full mastitis control programme with those in 247 herds in the partial and no mastitis control groups. Cases of clinical mastitis during the three year period were recorded in 73 herds in the full mastitis control group. The problems of applying the control routines are presented with observations on clinical mastitis, bulk milk cell count, milk production and milk quality. After three years, herds in the programme had on average increased milk production by 75 gallons a cow, achieved a 14.6 per cent reduction in the incidence of clinical mastitis, and improved the milk total solids percentage by one milk quality payment class. 相似文献
17.
Data derived from 340 dairy herds, mainly in southern England, between April 1998 and March 1999, showed that the average total culling rate was 22.1 per cent, with 5.6 per cent for infertility, 3.6 per cent for mastitis, 1.7 per cent for lameness, 2.0 per cent for poor milk yield, 3.7 per cent for age and 5.5 per cent for miscellaneous reasons which included death. The average annual rate of assisted calvings was 8.7 per cent, of injury 0.9 per cent, digestive disease 1.3 per cent ketosis 0.4 per cent, hypomagnesaemia 0.7 per cent, hypocalcaemia 5.3 per cent, mastitis 36.6 per cent, and lameness 23.7 per cent. There was a significant association (P<0.001) between higher rates of mastitis in cows housed in straw yards as opposed to cubicles and also between higher rates of lameness in cows housed in cubicles as opposed to yards (P<0.015). However, there were farms with low rates of mastitis in cows kept in straw yards and low rates of lameness in cows kept in cubicles. Larger herds tended to have more problems with lameness and higher bulk milk somatic cell counts (BMSCC). There was a positive association between BMSCC and mastitis rate. 相似文献
18.
During recent years the prevalence of coagulase-negative staphylococci in milk samples from Dutch dairy cows has increased. In 1999 16.2% of the bacteria isolated from milk collected from cows with subclinical mastitis were coagulase-negative staphylococci. In 2004 this proportion was 42.2%. The proportion of coagulase-negative staphylococci of the bacteria isolated from milk samples from cows with clinical mastitis was 7.3% in 1999 and 14.1% in 2004. In this study, the susceptibility of 108 coagulase-negative staphylococci to oxacillin, cefquinome, streptomycin, neomycin, penicillin, and the combination of nafcillin, penicillin, and streptomycin was tested. The isolates were cultured from milk collected from cows with mastitis and typed using the Api-Staph system. Eight species were identified. Staphylococcus chromogenes was the predominant species (41.7%), followed by Staphylococcus xylosus (15.7%) and Staphylococcus simulans (10.2%). With the agar dilution method all strains proved to be sensitive to cefquinome and 90% to oxacillin. Three isolates (2.8%) were mecA-positive. Despite the agar dilution results, these three isolates should be considered resistant to all beta-lactam antibiotics (penicillins, penicillins combined with a beta-lactamase inhibitor and all generations of cephalosporins). In the agar diffusion test, all isolates proved to be sensitive to the combination of nafcillin-penicillin-streptomycin, 99% were sensitive to neomycin and 1% intermediate sensitive, and 95% were sensitive to streptomycin, 4% resistant, and 1% intermediate sensitive. The coagulase-negative staphylococci were highly resistant to penicillin (37.4%), although the level of resistance varied between species, from 0% for Staphylococcus simulans to 100% for Staphylococcus saprophyticus. Because coagulase-negative staphylococci are resistant to several antibiotics, sensitivity testing is important for targeted treatment of mastitis. 相似文献
19.
Clinical mastitis was monitored in six Somerset dairy herds for one year. The herds all had three-month geometric mean bulk milk somatic cell counts of less than 250,000 cells/ml. Escherichia coli was the predominant pathogen isolated on all the farms and in all months of the year. Environmental pathogens accounted for 61.4 per cent of all cases of clinical mastitis and for 79.3 per cent of the mastitis cases in which an aetiological agent was identified. The mean annual incidence was 41.6 cases per 100 cows (range 14 to 75). Affected cows suffered a mean of 1.5 cases and 16.4 per cent of quarters suffered at least one repeat case. Mastitis due to E. coli was more severe than mastitis due to other causes and it tended to be more severe in early lactation and during the housing period. Mastitis was significantly more severe (grades 2 and 3) in the herd with the lowest bulk milk somatic cell count and in the herd which was kept indoors throughout the year than in the other four herds. Mastitis was fatal in 2.2 per cent of cases and resulted in the death of 0.6 per cent of the lactating cows. 相似文献
20.
Patterns of nonclinical intramammary infection in a ewe flock 总被引：1，自引：0，他引：1
W D Hueston N R Hartwig J K Judy 《Journal of the American Veterinary Medical Association》1986,188(2):170-172
Coagulase-negative staphylococci were the most frequent bacterial isolates from nonclinical intramammary infections (NIMI) in a ewe flock. The prevalence of NIMI was 22.9% of the udder halves at lambing and decreased to 12.5% or less between week 2 and week 6 of lactation. The decrease was due mainly to the elimination of infections involving coagulase-negative staphylococci. The frequency of new NIMI in the first 6 weeks of lactation was less than 1% of the noninfected udder halves per week. The prevalence of NIMI increased steadily from 16.1% of the udder halves at the time of weaning the lambs to 29% at postweaning week 3. The new infection rate averaged 9.7% per week during the postweaning 3 weeks. The principal bacterial isolate in the new NIMI was coagulase-negative staphylococcus. Nonclinical intramammary infection in a ewe flock was monitored by bacteriologic cultural examinations of milk samples obtained from both udder halves of 24 ewes during early lactation and of 31 ewes in the same flock during the early postweaning period. The patterns of NIMI were similar to the patterns reported in cattle. 相似文献