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1.
Bovine mastitis due to unicellular, achlorophyllous algae of the genus Prototheca is a serious and complex ailment that accounts for high economic losses in the dairy industry. Bovine protothecal mastitis has been almost exclusively associated with only one species Prototheca zopfii. Recently, based on the 18S rDNA sequence analysis, P. zopfii has been divided into three genotypes (1-3), of which P. zopfii genotype 3 has been given the status of a new species Prototheca blaschkeae sp. nov. The aim of this study was to investigate the genotypic composition of the population of P. zopfii bovine mastitis isolates from Poland, according to that threefold classification. Of the 44 isolates tested, 43 (98%) were identified as P. zopfii genotype 2. Only one isolate was assigned to the newly established P. blaschkeae species. These findings clearly show the predominance of the P. zopfii genotype 2 in the etiology of bovine mammary protothecosis in Poland, but also underline the involvement of P. blaschkeae in the disease. The study is the first to provide molecular characterization of Polish P. zopfii mastitis isolates, collected from different regions of Poland.  相似文献   

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This study is the first investigation on Japanese isolates of Prototheca zopfii from bovine mastitis and the cow-barn surroundings by molecular characterization to clarify routes of infection for bovine protothecal mastitis. We performed isolation of Prototheca from cow-barn surroundings (drinking water, sewage and feces) and milk samples from cases of bovine mastitis. Genotypes of the 32 isolates of P. zopfii from cow-barn surroundings and 67 isolates from mastitis were analyzed by genotype-specific PCR assays and restriction fragment length polymorphism (RFLP) assays. All mastitis isolates were identified as P. zopfii genotype 2. Conversely, 29 isolates from cow-barn surroundings were identified as P. zopfii genotypes 1 and 3 isolates as genotype 2, respectively. Given these results, both genotypes of P. zopfii could exist in cow-barn surroundings, but no sites were identified as frequent sources of P. zopfii genotype 2. P. zopfii isolates should thus be further explored with regard to genotype to clarify the reservoir of etiological agents in bovine Prototheca mastitis.  相似文献   

4.
Bovine mastitis due to Prototheca zopfii leads to reduced milk production and is difficult to cure. Therefore, prevention is the best approach and this is best achieved through the use of effective disinfectants. The aim of this study was to evaluate the in vitro algaecide efficacy of conventional disinfectants against strains of P. zopfii genotype 1 and 2. The minimal algaecide concentration (MAC) of alkyldiaminoethylglycine hydrochloride, chlorhexidine, dioxide chlorine, povidone iodine and sodium hypochlorous acid against 10 isolates and the type strain (SAG2063(T)) of P. zopfii genotype 1 as well as 10 isolates and the type strain (SAG2021(T)) of P. zopfii genotype 2 were examined using the micro dilution method. This in vitro study indicated that alkyldiaminoethylglycine hydrochloride, chlorhexidine, povidone iodine and sodium hypochlorous acid, but not dioxide chlorine, are effective against both genotypes of P. zopfii.  相似文献   

5.
Antibacterial activity of bovine lactoferrin hydrolysates (LFH) on microorganisms isolated from bovine mastitis, and superoxide (O(2)(-)) production of bovine neutrophils were evaluated. Antibacterial effects of LFH were measured in vitro against Staphylococcus aureus, coagulase-negative staphylococci, Streptococci, Enterococci, Escherichia coli, Klebsiella pneumoniae, yeast-like fungi and Prototheca zopfii isolated from clinical cases of bovine mastitis. To compare susceptibilities against LFH, minimal inhibitory concentration (MIC) values were determined by a micro-plate assay method. Most organisms were sensitive to LFH. Prototheca zopfii was highly sensitive to LFH; the growth of the microorganism was inhibited completely even at 1 mug/ml. Staphylococcus aureus and Escherichia coli were resistant to LFH. The production of O(2)(-) by bovine neutrophils was used to evaluate the effect of LFH administration on functional activity. Increase in O(2)(-) production by bovine neutrophils occurred upon addition of LFH to neutrophils. These results demonstrate that LFH possesses antibacterial activity against pathogens that cause mastitis and activates neutrophil superoxide production.  相似文献   

6.
In the last 2 years 223 cases of bovine mastitis caused by Prototheca zopfii infection were identified in 32 large-scale dairy herds. All of these farms were in Hungary, which has a continental type, temperate zone climate. Both the sporadic and epidemic forms of P. zopfii mastitis were observed. All the herds affected by the epidemic form had poor hygienic conditions and suffered from several managerial faults, but no specific predisposing factors could be identified. In almost all of the cases, the type II variant of this pathogen was isolated; however, the type III variant was isolated from three cows. The cows had a higher chance of new infection in the early weeks of lactation and in the summer. The P. zopfii infection usually resulted in a chronic subclinical, or mild clinical, inflammatory process in the udder, and was followed by a dramatic loss in milk production and a permanent increase in somatic cell count. The histopathological findings could be characterized as a progressive interstitial mastitis associated with alveolar atrophy. The self-recovery rate was very low.  相似文献   

7.
Protothecosis is a severe form of mastitis in dairy cows caused by colorless algae of the genus Prototheca. Since P. zopfii is highly resistant to all known chemotherapeutics, infected cows must be removed from the herd. Eradication measures are difficult since many chronically infected cows may become intermittent shedders. Therefore, cultural methods are insufficient for control measures. In order to eradicate Prototheca zopfii-mastitis in dairy cattle herds, two isotype specific indirect ELISA for detection of IgA and IgG1 in whey were used in a dairy herd highly affected with protothecal mastitis. All cows (n = 313) were tested four times in intervals of six months. Milk specimens were examined in parallel by cultivation and serologically using two indirect ELISA systems for specific IgA and IgG1 in whey. Cows tested Prototheca positive were consequently separated from the herd and slaughtered. At the first examination, 15.6% of the animals were found positive by culture, and 23.3% were positive in at least one of the ELISA systems. Within two years, protothecal prevalence and incidence decreased to zero indicating that the eradication strategy used was successful. In summary, serological identification of P. zopfii-infected lactating cows is an useful tool to eradicate protothecal bovine mastitis in infected herds.  相似文献   

8.
目前已有12个国家报道无绿藻性奶牛乳房炎,造成严重的经济损失并对公共安全存在潜在的危害.2010年春季,北京地区某奶牛场暴发中型无绿藻引起的临床型乳房炎.从患有临床型乳房炎的10头奶牛的11个乳区分离到8株酵母样微生物,鉴定为中型无绿藻.用16种抗生素药敏纸片进行药敏试验,结果显示中型无绿藻仅对庆大霉素、链霉素和阿米卡星等氨基糖苷类抗生素敏感.同化试验证明该分离株能发酵葡萄糖和丙三醇.本试验在我国首次报道了中型无绿藻能引起奶牛临床型乳房炎.  相似文献   

9.
In order to clarify the epidemiology of bovine protothecal mastitis, 30 Prototheca zopfii mastitis isolates were genetically investigated. Based on the 18S rDNA, which allows a differentiation of the former species P. zopfii in two distinct P. zopfii genotypes and Prototheca blaschkeae sp. nov., newly developed genotype-specific PCR-assays as well as RFLP-assays were applied.

All mastitis isolates investigated could be assigned to P. zopfii genotype 2 suggesting that this genotype is the aetiological agent of bovine Prototheca mastitis.  相似文献   


10.
Development of an appropriate Staphylococcus aureus vaccine for bovine mastitis has eluded researchers for decades. The ability of S. aureus to form a protective exopolysaccharide capsule has posed a major obstacle because of the multiple serotypes and the poor immune response elicited by exopolysaccharides. This study characterized S. aureus serotypes isolated from cases of bovine mastitis obtained from veterinary diagnostic laboratories that service 44% of the dairy cattle in the United States. Major milk producing areas of the northeast, north central, Pacific coast and southwest were proportionately represented. Sub-samples of mastitic milk that contained S. aureus were frozen and sent to our laboratory for strain serotyping. The only other regional serotyping of S. aureus from bovine mastitis to date was done in France. The primary serotypes found were types 5 (51%) and 8 (18%) and 31% were non-typeable. In the current study, serotype 5 accounted for 18% of the isolates and serotype 8 for 23%. More importantly 59% of the isolates were not typeable with either type 5 or 8 antisera. These data indicate that S. aureus vaccines employing serotypes 5 and 8 would only be marginally effective in the United States. These data also suggest that development of a S. aureus vaccine for bovine mastitis should take into account regional variation in S. aureus serotypes.  相似文献   

11.
Sources of Prototheca spp in a dairy herd environment   总被引:1,自引:0,他引:1  
A source of Prototheca spp causing mastitis in a herd of 263 milking cows in North Carolina was investigated. Of 38 samples from the dairy environment, 18 (47%) contained Prototheca spp. Isolation sites included cattle drinking water; a feed trough; mud, dirt, and excreted feces from a dirt lounging area; water, sludge, mud, and vegetation from a creek in the lounging area; and the floor of a freestall barn. Samples were collected from 5 additional dairies, including one dairy with and 4 dairies without a history of protothecal mastitis. Prototheca spp were isolated from 48 (25%) of 190 samples from various sites on all 6 dairies. Isolates were P zopfii (45; 94%) and P wickerhamii (3; 6%). Isolation frequency ranged from 4 to 47% of samples/dairy. There was no apparent difference in the isolation frequency of Prototheca spp from samples from dairies with or without a history of protothecal mastitis. Sites characterized by wetness and the presence of organic matter most commonly yielded Prototheca spp. Because Prototheca spp appear to be common in the dairy environment, factors in addition to presence in the environment may be important in development of protothecal mastitis.  相似文献   

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Background: Bovine mastitis is the most common and costly disease of lactating cattle worldwide. Apart from milk somatic cell count(SCC) and somatic cell score(SCS), serum cytokines such as interleukin-17(IL-17) and interleukin-4(IL-4) may also be potential indicators for bovine mastitis. The present study was designed to investigate the effects of single nucleotide polymorphisms(SNPs) in bovine IL-17 F and IL-17 A genes on SCC, SCS and serum cytokines in Chinese Holstein and Inner-Mongolia Sanhe cattle, and to compare the m RNA expression variations of the cows with different genotypes.Results: A total of 464 lactating cows(337 Holstein and 127 Inner-Mongolia Sanhe cattle) were screened for SNPs identification and the data were analyzed using fixed effects of herd, parity, season and year of calving by general linear model procedure. The results revealed that SNP g.24392436 C T in IL-17 F and SNP g.24345410 A G in IL-17 A showed significant effects on SCC and IL-4 in Holstein(n = 337) and on IL-17 and IL-4 in Sanhe cattle(n = 127). The homozygous GG genotype of SNP g.24345410 A G had significantly higher m RNA expression compared with the heterozygous AG genotype.Conclusions: The results indicate that IL-17 F and IL-17 A could be powerful candidate genes of mastitis resistance and the significant SNPs might be useful genetic markers against mastitis in both dairy and dual purpose cattle.  相似文献   

14.
An outbreak of contagious mastitis occurred among cattle on a farm, and bovine herpesviruses were isolated from the affected mammary tissues, scabs and abscess discharge of the cattle. A bovine herpesvirus type 4 (BoHV-4)-specific fragment was amplified from the isolates by polymerase chain reaction (PCR). Restriction endonuclease analyses demonstrated that the isolates were related to Movar-like European type BoHV-4. To determine the ratio of BoHV-4 subclinical infection in the cattle, a genomic survey was performed by PCR for cattle that were moved to the animal hygiene service station in Ibaraki prefecture. The BoHV-4 genome was occasionally detected in peripheral blood leukocytes, lymph nodes and nervous tissues. The rate of BoHV-4 subclinical infection was relatively high in the cattle.  相似文献   

15.
Molecular and biological characterisation of Cryptosporidium in pigs   总被引:1,自引:0,他引:1  
OBJECTIVE: Genetic and biological characterisation of 12 isolates of Cryptosporidium from pigs and comparing them with Cryptosporidium isolates from humans and cattle. DESIGN: Cryptosporidium isolates from pigs were compared with those obtained from human and cattle using rDNA sequence analysis. The infectivity of two of the porcine isolates was determined in neonatal mice and the clinical history of the infected pigs recorded. RESULTS: Pig-derived isolates of Cryptosporidium exhibited two distinct genotypes; a porcine genotype and a bovine genotype, which is common to cattle and other livestock. The porcine genotype did not produce any infection in neonatal mice whereas the bovine genotype did. CONCLUSION: Two distinct genetically and biologically differing strains of Cryptosporidium appeared to be associated with acute diarrhoea in pigs. Whether Cryptosporidium was a primary or secondary pathogen is unclear but warrants further investigation. As the bovine genotype is known to infect humans, the results suggest that pigs can act as reservoirs of cryptosporidial infections for humans and other live-stock. The zoonotic potential of the pig-adapted genotype is uncertain and requires further study.  相似文献   

16.
Prototheca zopfii has been considered one of the most important causes of environmental mastitis in Brazil. These algae are refractory to conventional therapy and cause great damage to the mammary gland. The present study evaluated the in vitro algaecide effect of sodium hypochlorite and iodine based antiseptics on 27 P. zopfii strains isolated from the milk of cattle. Low concentrations of sodium hypochlorite (0.0390625-0.15625%) and iodine (0.15625-0.625%) were effective against the isolates. These antiseptics may be recommended for hygiene routines, pre and postdipping and cauterization of bovine mammary glands infected by P. zopfii.  相似文献   

17.
Staphylococcus aureus is a major pathogen for cattle, causing various forms of subclinical and clinical mastitis. Two groups of virulence factors (leukotoxins and superantigens) are supposed to play an important role in the initiation and/or the exacerbation of this disease. In order to detect all known and putative members of leukotoxins and SAgs (superantigens), we tested secreted factors of different S. aureus isolates in flow cytometry-based assays.Isolates were sampled from 68 cows of different farms and cultured for 24h in vitro. Supernatants were then coincubated with purified polymorphonuclear granulocytes (PMN) or combinations of blood mononuclear cells (MNC) and PMN. Viable PMN and MNC were determined by quantitative flow cytometry. In addition, we recorded the proliferation-inducing potential of isolate supernatants for bovine MNC. Based on these criteria, the supernatants of S. aureus isolates fell in three groups. The first group (n=32), termed LT-SNs (leukotoxin-containing supernatants), killed purified granulocytes (neutrophils and eosinophils) in vitro. The second group of supernatants (n=20), termed SAg-SN (superantigen-containing supernatants), induced activation and proliferation of mononuclear cells (MNC) and, only in the presence of MNC, resulted in a selective depletion of neutrophils after 24h in vitro. The third group of supernatants (n=16) contained neither LTs or SAgs. Functionally, SAg-SNs behaved like purified staphylococcal enterotoxin A (SEA) or SEB tested in parallel. The absence of SAg-like activity in LT-SNs was confirmed by heat treatment of LT-SNs, which destroyed the leukocytotoxic activity, but did not reveal any MNC-activating potential. This study, therefore, suggests, that pathogenic S. aureus isolates either produce leukotoxins or superantigens and that both groups of virulence factors can easily be differentiated by the functional assays described.The prevalence of leukotoxin- or superantigen-producing isolates was comparable among cattle with subclinical (LT=41%; SAg=30.8%) mastitis. The higher frequency of LT-producing isolates in cases of clinical mastitis (LT=55.2%; SAg=27.6%) was not significant. At least, these findings argue against the dominant role of superantigens or leukotoxins in S. aureus-induced bovine mastitis.  相似文献   

18.
为研究奶牛乳房炎金黄色葡萄球菌(Staphylococcus aureus,SA)主要毒力因子的分布情况,本试验利用PCR对70株临床型乳房炎、55株隐性乳房炎金黄色葡萄球菌的8种主要毒力基因进行检测。结果显示,nuc、ClfA、TSST-1、PVL、Hla、Hlb、FnBPA和FnBPB 8种毒力基因在临床型乳房炎SA菌株中的检出率分别为:100.0%(70株)、100.0%(70株)、0(0株)、5.7%(4株)、100.0%(70株)、11.4%(8株)、97.1%(68株)和100.0%(70株);在隐性乳房炎SA菌株中的检出率分别为:100.0%(55株)、100.0%(55株)、0(0株)、70.9%(39株)、98.2%(54株)、9.1%(5株)、100.0%(55株)和100.0%(55株)。结果表明,nuc、ClfA、Hla、Hlb和FnBPA 5种毒力基因是引起奶牛乳房炎的SA的最主要毒力基因;PVL基因可能是引起隐性乳房炎的重要致病基因。  相似文献   

19.
奶牛临床型乳房炎病原菌的分离与鉴定   总被引:1,自引:1,他引:1  
奶牛乳房炎是奶牛常见病和多发病之一,其病因复杂,难以防制,给奶牛饲养业带来了巨大的经济损失。作者通过对某奶牛场的奶牛临床型乳房炎病原菌进行分离、鉴定,从105份样品中共分离出76株细菌,经培养特性、染色镜检、生化鉴定等试验,鉴定出无乳链球菌58株,占分离菌的76.32%;大肠杆菌18株,占分离菌的23.68%。本试验结果表明,无乳链球菌是奶牛临床型乳房炎的主要病原菌,其次是大肠杆菌。这为奶牛乳房炎的防制提供了重要依据。  相似文献   

20.
A total of 5,142 kidney tissue samples and 5,111 serum samples from mature cattle in 49 states and Puerto Rico were collected at slaughter. Age of cattle ranged from 1 to 16 years (mean, 6.6 years). Leptospires were isolated from 88 (1.7%) kidney tissues, and 2,493 (49%) sera contained antibodies against 1 or more of 12 Leptospira interrogans serovars. Leptospires were observed by immunofluorescence in 41 (0.8%) kidney tissues. Using agglutinin-absorption tests, 73 (83%) isolates were identified as serovar hardjo, 11 (12.5%) as serovar pomona, and 4 (4.5%) as serovar grippotyphosa. By use of restriction endonuclease analysis studies of chromosomal DNA, all isolates differed from reference serovars but were identical to strains previously isolated from cattle or swine in the United States. Of the serovar hardjo isolates, 85% were identical to restriction endonuclease analysis type (genotype) hardjo-bovis A and 11 (15%) were identical to genotype hardjo-bovis B. Serovar pomona isolates were identical to genotypes kennewicki A (64%) or kennewicki B (36%), and serovar grippotyphosa isolates were identical to the RM 52 strain. Isolation rates were significantly (P less than 0.001) higher for beef cattle than for dairy cattle and were higher (P less than 0.001) for bulls than for cows. Combined culture and immunofluorescence results indicated that 2% of mature cattle were renal carriers of leptospires.  相似文献   

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