共查询到20条相似文献，搜索用时 828 毫秒
1.
V R?zicková 《Veterinární medicína》1991,36(7):393-399
A detailed analysis of biotypes of Staphylococcus aureus, as related to their origin and enterotoxigenicity, was performed, using 432 strains isolated from bulk milk, milking machines, quarter milk samples collected from mastitic cows, and cowherds and milkers. All strains coagulated rabbit blood plasma and produced thermonuclease (Tab. I). Human strains differed from bovine ones mostly in the production of alpha-haemolysin (94%) and fibrinolysin (66%). Biotypes C1 (35%) and C2 (38%) dominated clearly among the strains isolated from quarter milk samples. The findings of 13% of biotype A and 8% of biotype D suggest that other sources of udder infections than mastitic cows were involved. Almost 19% of human strains and two strains isolated from quarter milk samples were identified as the recently defined type G. The production of enterotoxins (Tab. III) of was associated mostly with strains of human origin (69%) and with biotypes G (35%) and A (31%). Three enterotoxigenic strains belonged to the biotype B and one strain was not classifiable. 相似文献
2.
Blum S Heller ED Krifucks O Sela S Hammer-Muntz O Leitner G 《Veterinary microbiology》2008,132(1-2):135-148
Eleven Escherichia coli isolates from clinical bovine mastitis cases (mastitic strains) and 11 from the cowshed environment (environmental strains) were compared, to determine if the former were a subset of the latter. The mastitic and environmental strains could not be distinguished according to O antigen and antibiotic sensitivity. All mastitic isolates showed significantly (P<0.0001) faster growth in milk and faster lactose fermentation than most (approximately 64%) environmental strains, but growth rates in nutrient broth did not differ. The rates of lactose fermentation and growth in milk were positively correlated. Adhesion and phagocytosis of mastitic strains by bovine PMN were significantly (P<0.0001) lower than those of environmental strains, and correlated negatively with growth in milk and lactose fermentation. The average percentages of killing by bovine leukocytes in the two sources were not statistically different. All mastitic strains were serum sensitive, whereas most ( approximately 72%) environmental ones were resistant. Finally, pulse-field gel electrophoresis revealed two main pulse type clusters, sharing a similarity coefficient of 79%. Cluster 1 comprised only environmental strains, whereas cluster 2 comprised mostly mastitic strains and only three environmental ones. Four mastitic strains shared a similarity coefficient of less than 74% with the other strains and were not included in the clusters. Our results suggest that clinical bovine mastitis E. coli isolates may form a subset of the general environmental E. coli population; they seem better able to multiply in the udder medium and to evade the host cellular innate immune response, and are genetically distinct from most environmental strains. 相似文献
3.
Coliform organisms were isolated from bedding, udders of cows exhibiting acute or chronic mastitis, and milk of cows tested for udder pathogens. The bactericidal activity of standard bovine serum was tested on 362 isolates, of which 2.4% were killed at a serum dilution of less than 1:5; 2.7% were killed at a dilution of 1.5; 3.0% were killed at a dilution of 1:12.5; and 4.4% were sensitive to a dilution of 1:25. Organisms isolated from mastitic udders were not killed by serum. Sensitivity to agglutination in 1:500 solution of acriflavine was tested on 157 isolates, and only 54 had any degree of agglutination. Of these 54, only 4 organisms had any susceptibility to killing by serum. Results suggest that most organisms in the environment of the cow are resistant to serum, few serum-sensitive coliforms cause mastitis, and agglutination in acriflavine (indicating organisms in the rough phase) does not correlate with sensitibity to serum. 相似文献
4.
5.
Phagocytosis of serum-resistant and serum-sensitive coliform bacteria (Klebsiella) by bovine neutrophils from blood and mastitic milk 总被引：1，自引：0，他引：1
Phagocytic activity of neutrophil leukocytes from bovine blood and mastitic milk was determined for 2 strains of Klebsiella, 1 resistant and the other sensitive to serum bactericidal activity. Both strains were easily phagocytized in the presence of an opsonic agent, but milk neutrophils seemed to be less efficient than blood neutrophils in this respect. Phagocytosis was maximal after incubation for 60 minutes at 37 C and decreased markedly with reduction in incubation temperature. The opsonic activity of mastitic milk was considerably higher than that of normal milk and approached that of fresh bovine serum. Precolostral calf serum was deficient in opsonic activity and anti-bovine leukocyte serum was antiphagocytic. 相似文献
6.
Comparison of the herpesviruses of cattle by DNA restriction endonuclease analysis and serologic analysis 总被引：1，自引：0，他引：1
F A Osorio D E Reed M J Van der Maaten C A Metz 《American journal of veterinary research》1985,46(10):2104-2109
Reference strains and field isolates of herpesviruses recovered from cattle in the United States were compared by restriction endonuclease (RE) analysis and the indirect fluorescent antibody test. As a result of these comparisons, 5 major biotypes of bovine herpesvirus (BHV) were defined. These types were (i) infectious bovine rhinotracheitis virus (BHV-1), (ii) bovine herpes mammillitis virus (BHV-2), (iii) malignant catarrhal fever (MCF) virus (herpesvirus alcelaphinae), (iv) the group of slow-growth isolates represented by the prototype strain Movar 33/63 (bovine cytomegalovirus candidate), and (v) the syncytia-forming Pennsylvania 47 strain. Bovine herpesvirus-1 and BHV-2 did not cross-react serologically with any other type of BHV tested. A low, but consistent level of serologic cross-reactivity was detected among MCF virus, the Movar group, and Pennsylvania 47. Several nonsyncytial, slow-growth strains, which were recovered from dissimilar clinical syndromes and were serologically related to Movar 33/63, exhibited similar DNA RE cleavage patterns, confirming their identity as members of a single type. There was no isolate from American domestic cattle similar to the African MCF virus, which has been sporadically isolated from exotic ruminants in the United States. The African MCF virus isolated during a MCF epizootic in a United States zoo exhibited some DNA RE cleavage differences in comparison with the MCF virus world prototype strain WC 11, indicating that strain diversity exists within this biotype. 相似文献
7.
The minimum inhibitory concentration (MIC) of ten antimicrobial drugs for 287 S. aureus strains recently isolated from bovine mastitic milk in different herds all over Sweden was determined. The minimum bactericidal concentration (MBC) of benzylpenicillin for 20 strains was determined. Thirty strains (10%) produced beta-lactamase. All strains were susceptible to oxacillin and neomycin, and more than 90% to streptomycin, trimethoprim-sulphamethoxazole chloramphenicol, erythromycin and tetracycline, whereas all were resistant to sulphamethoxazole. None of 20 strains investigated was tolerant to benzylpenicillin. However, S. aureus strains, isolated from bovine milk, should be tested for beta-lactamase production prior to treating mastitic cases with beta-lactam drugs. 相似文献
8.
The expression of capsule in serum-soft agar by Staphylococcus aureus isolated from bovine mastitis 总被引：8，自引：0，他引：8
Strains of Staphylococcus aureus were isolated from bovine mastitis, subcultured and maintained in the laboratory for up to 3 years. Encapsulation was assessed by production of a diffuse colony in serum-soft agar. Eight (4%) of 200 strains were encapsulated. Three rapid passages of the remaining 192 strains through either brain-heart infusion broth containing 30% serum or modified 110 medium retrieved the capsule in 75%, but this was rapidly lost after subculture on blood agar. The stimulation of capsule production was studied in 18 of these strains by addition of various components to the passaging medium. Heat-labile factors in serum, milk and mastitic milk enhanced capsule production while bovine serum albumin, an extract of polymorphonuclear leucocytes, NaCl and immunoglobulins had minimal effect. The results indicate that encapsulation is common in bovine staphylococci and while it is lost on subculture, may be retrieved under appropriate conditions. 相似文献
9.
Jha VC Morita Y Dhakal M Besnet B Sato T Nagai A Kato M Kozawa K Yamamoto S Kimura H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(8):819-825
In Nepal, mycobacterial isolates obtained from the milk and feces of buffaloes and cattle that were positive for the single intradermal cervical tuberculin (SICT) tests were genetically identified. A total of 36 mycobacterial strains were isolated from 39% of the buffaloes (14 of 36) and 34% of the cattle (11 of 32). Of the 36 strains, 13 were identified as M. bovis, and these strains were isolated from 17% of the buffaloes (6 of 36) and 16% of the cattle (5 of 32). M. bovis was isolated from both the milk and feces of one buffalo and one cattle, the milk alone of three buffaloes and three cattle, and the feces alone of two buffaloes and one cattle. These results suggest that milking buffaloes and cattle infected with M. bovis exist in Nepal. The remaining 23 strains were atypical mycobacteria. A program for the elimination of bovine tuberculosis should be implemented as soon as possible, and the public health education and proper hygienic practices may be required. 相似文献
10.
In vitro methods were used to test the hypothesis that Escherichia coli from bovine mastitis are essentially no different from isolates from bovine feces. Fifty E. coli isolates from bovine mastitic milk, 50 from feces of mastitic cows and 50 from feces of healthy cows were compared with respect to biochemical properties and certain potential virulence factors. There were no significant differences among the groups in tests for biotype; production of colicins, colicin V, or Vero cell cytotocity; and growth in 90% gnotobiotic calf serum or 90% normal milk whey. Resistance to killing in 90% gnotobiotic calf serum varied from 66 to 84%. Most isolates grew in normal whey: the percentage in a group varied from 86 to 96. Mastitic milk isolates were significantly different from the fecal isolates in adonitol fermentation (P0.006), production of aerobactin (P0.026), and ability to grow in 90% mastitic whey (P0.00004). However, only 40% of mastitis E. coli fermented adonitol and only 20% produced aerobactin. Ninety-six percent of mastitic milk E. coli grew in mastitic whey, whereas 64% and 60%, respectively, of mastitic fecal and normal fecal isolates grew in this medium. It is concluded that none of the properties that were investigated constitute potential virulence factors or markers for ability to induce mastitis; the data are consistent with the hypothesis that mastitic E. coli are simply opportunistic pathogens. 相似文献
11.
12.
肺炎克雷伯氏菌为革兰氏阴性菌,是重要的条件性致病菌和医源性感染菌之一,也是引起奶牛乳房炎的重要病原菌。本研究对30份奶牛乳房炎乳样进行了病原菌的分离鉴定,并对分离菌进行药物敏感试验;结果表明,本次共分离肺炎克雷伯氏菌3株,遗传进化树关系显示分离菌株KP1、KP3与CP031810株、CP031562株、CP032185株亲缘关系较近,分离株KP2则相对较远。药物敏感试验结果显示,3株分离株均对阿莫西林、头孢他啶、头孢曲松耐药,对链霉素、庆大霉素表现敏感,分离菌株KP1和KP3对青霉素表现中度敏感,菌株KP2则表现耐药。本研究为奶牛场针对该菌的防控提供了基础数据。 相似文献
13.
奶牛隐性乳房炎的病原检测与小白鼠致病性研究 总被引：3，自引：1，他引：2
本研究以新疆乌鲁木齐地区的2个奶牛场隐性乳房炎患牛为试验对象,共分离鉴定出21种91株引起奶牛乳房炎的主要病原菌,其中葡萄球菌28株（30.78%）,链球菌21株（23.07%）,杆菌25株（27.48%）,其他细菌17株（18.67%）。对主要病原菌通过动物试验确定致病力较强的菌为金黄色葡萄球菌、克雷伯氏菌和大肠杆菌。同时对17大类主要病原菌共30种药物的药敏试验结果表明,在奶牛隐性乳房炎中应用较多的青霉素、四环素等抗生素对常见致病菌几乎无效,而左氧氟沙星、呋喃妥因、头孢噻肟、阿米卡星则显示出较好的抑菌作用。 相似文献
14.
M M Garcia B W Brooks G M Ruckerbauer C E Rigby L B Forbes 《Canadian journal of veterinary research》1988,52(3):338-342
Brucella abortus strains were isolated from bovine tissue and milk samples from seven Ontario herds. The isolates were characterized by colonial morphology, requirement of CO2 for growth, lysis by Tbilisi phage, biochemical tests and agglutination in monospecific sera. They resembled B. abortus biotype 2 (on the basis of sensitivity to thionin and basic fuchsin) and biotype 4 (on the basis of agglutination with anti-Brucella "M" but not anti-Brucella "A" absorbed sera). Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of these isolates and B. abortus biotypes 1, 2 and 4 showed similar profiles. Immunoblots with anti-A and anti-M absorbed sera showed different antigenic regions reacting with the specific sera and also confirmed that the atypical B. abortus isolates were serologically similar to biotype 4. 相似文献
15.
The objective of this study was to determine the frequency of different mastitis pathogens in 1255 milk samples collected from 368 lactating cows on 24 dairy farms in Korea during 2008. The proportion of cows and quarter milk samples having SCC ? 200,000 cells/ml, an indicator of udder infection, was 54.3% (200/368 cows) and 35.5% (446/1255 samples), respectively. Of the 446 milk samples subjected to bacteriological examination, 16.5% (74) showed no bacterial growth and 3.5% (16) were contaminated. In total, 356 of 1255 (28.3%) samples were bacteriologically positive, from which 415 bacteria were isolated. The most frequently isolated pathogen was coagulase-negative staphylococci (40.7%), followed by Gram-negative bacteria (19.5%) other than Escherichia coli, Staphylococcus aureus (12.2%), Streptococcus uberis (5.3%), Enterococcus spp. (4.8%), E. coli (4.5%), and environmental streptococci (3.1%) other than S. uberis. This study demonstrates that environmental pathogens were the vast majority of bacteria isolated from mastitic bovine milk samples in Korea. 相似文献
16.
O Skardová 《Veterinární medicína》1989,34(5):257-266
Four strains of nutritionally variant streptococci (NVS) were isolated from the milk of mastitic cows and one strain from the lungs of a laboratory Norway rat which died from suppurative pneumonia. In primary cultivation NVS grew aerobically and anaerobically within 48-hour incubation at a temperature of 37 degrees C as minute nonhemolytic satellite colonies around a previously overlaid S. aureus strain or around other gram-positive and gram-negative bacteria. In the first subcultures NVS were growing in nutrient media enriched with 10% bovine serum and 5% staphylococcal filtrate, or 0.02% to 0.002% pyridoxal hydrochloride. All isolates did not grow in presence of 10%, 40% bile, and 6.5% of sodium chloride, neither did they grow at a temperature of 45 degrees C, they did not hydrolyze sodium hippurate, esculin, arginine, they did not produce levane and dextran from saccharose, they produced acid from mannitol, sorbitol, inulin, lactose, raffinose, trehalose, glucose, saccharose and maltose. Two strains produced acid from xylose and four strains from salicin. The strains isolated from mastitis did not have different biochemical properties from those isolated from a laboratory Norway rat with pneumonia. All strains of NVS were sensitive to chloramphenicol, ampicillin, gentamycin, lincomycin and cephalothin, four strains were sensitive to erythromycin and tyrosine, two to penicillin and one to streptomycin, oxytetracycline, chlortetracycline and novobiocin. All strains were resistant to neomycin, tetracycline, oxacillin and sulphonamides. The antigen prepared from the isolated strains by the method of Fuller did not react with any streptococcal group serum A-Z. 相似文献
17.
Corynebacterium pseudotuberculosis infection in an Israeli dairy cattle herd is described. The disease was characterized by ulcerative granulomatous lesions, which occurred in an epidemic form. Thirty-two cows and two heifers were affected, the ratio of the number affected to number at risk being 17.5 : 1 and 9.5 : 1, respectively. The culling rate was 50% of the affected animals. Most of the affected animals were cows (91.2%), with one first-calving cow (2.9%) and two heifers (5.9%) also affected. The infection occurred during the summer to autumn months (August-December), and lasted 118 days. The incubation period is about 2 months. The disease appeared in two clinical forms - cutaneous and mastitic - or as a mixed form. C. pseudotuberculosis organisms that were isolated from the ulcerative granulomatous lesions and from milk samples failed to reduce nitrate. A decrease in milk production (4%) and an increase in the bulk-milk somatic cell count from a herd mean of 240 x 10(3) mL(-1) to 460 x 10(3) mL(-1) were noted during the morbidity period. The organism was isolated from milk samples of eight animals (25%). Clinical, epizootiological and microbiological aspects of the infection are described. 相似文献
18.
Hisaeda K Hagiwara K Eguchi J Yamanaka H Kirisawa R Iwai H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(9):1009-1011
Concentrations of interferon-gamma (lFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) were determined in serum and whey samples from cattle with naturally occurring coliform mastitis for two weeks after onset using bovine INF-gamma and TNF-alpha-specific ELISA. In serum and whey samples from healthy cows. IFN-gamma was almost undetectable and TNF-alpha was detected at low levels. At the onset of illness, INF-gamma in sera and whey and TNF-alpha in whey from the mastitic cows were significantly higher than their respective values in healthy cows. Concentrations of IFN-gamma and TNF-alpha in whey from mastitic cattle decreased significantly as the cows recovered. 相似文献
19.
Optimal milk penicillin levels for the treatment of experimentally induced mastitis in cows. 
下载免费PDF全文
下载免费PDF全文 Infection of the mammary gland (mastitis) was produced by infusing ten quarters 2/cow x 5 cows) with Staphylococcus aureus strain 305. Mastitic and normal quarters were then infused with a preparation containing two levels of penicillin G (100,000 and 200,000 IU) in 10 mL of 3% aluminum monostearate and peanut oil. Milk penicillin levels were determined prior to treatment and twice daily for eight milkings after treatment. Normal and mastitic quarters infused with 200,000 IU had higher peak levels than those infused with 100,000 IU. Milk penicillin levels were similar in mastitic and normal quarters for the first three milkings after treatment. However, residues persisted for a longer time in milk from mastitic quarters. Penicillin was not detected in milk from the untreated control quarters nor in serum samples assayed during the experiment. The in vitro penicillin G sensitivity of the udder pathogen (MIC=0.039 and MBC=0.078 IU) was well below the milk penicillin levels for the first five milkings in all cases. However, infection recurred in two of the ten quarters (one receiving 100,000 IU and one receiving 200,000 IU). 相似文献
20.
Mycobacterium avium subsp. paratuberculosis from free-ranging deer and rabbits surrounding Minnesota dairy herds 下载免费PDF全文
下载免费PDF全文 Eran A. Raizman Scott J. Wells Peter A. Jordan Glenn D. DelGiudice Russell R. Bey 《Canadian journal of veterinary research》2005,69(1):32-38
The objectives of this study were to estimate the prevalence of Mycobacterium avium subsp. paratuberculosis (MAP) among deer and rabbits surrounding infected and noninfected Minnesota dairy farms using fecal culture, and to describe the frequency that farm management practices were used that could potentially lead to transmission of infection between these species. Fecal samples from cows and the cow environment were collected from 108 Minnesota dairy herds, and fecal pellets from free-ranging white-tailed deer and eastern cottontail rabbits were collected from locations surrounding 114 farms; all samples were tested using bacterial culture. In addition, a questionnaire was administered to 114 herd owners. Sixty-two percent of the dairy herds had at least 1 positive fecal pool or environmental sample. A total of 218 rabbit samples were collected from 90% of the herds, and 309 deer samples were collected from 47% of the herds. On 2 (4%) of the farms sampled, 1 deer fecal sample was MAP positive. Both farms had samples from the cow fecal pool and cow environment that were positive by culture. On 2 (2%) other farms, 1 rabbit fecal sample was positive by culture to MAP, with one of these farms having positive cow fecal pools and cow environmental samples. Pasture was used on 79% of the study farms as a grazing area for cattle, mainly for dry cows (75%) and bred or prebred heifers (87%). Of the 114 farms, 88 (77%) provided access to drylot for their cattle, mainly for milking cows (77/88; 88%) and bred heifers (87%). Of all study farms, 90 (79%) used some solid manure broadcasting on their crop fields. Of all 114 farms, the estimated probability of daily physical contact between cattle manure and deer or rabbits was 20% and 25%, respectively. Possible contact between cattle manure and deer or rabbits was estimated to occur primarily from March through December. The frequency of pasture or drylot use and manure spreading on crop fields may be important risk factors for transmission of MAP among dairy cattle, deer, and rabbits. Although the MAP prevalence among rabbits and deer is low, their role as MAP reservoirs should be considered. 相似文献