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1.
Rabbits of 19 rabbitries were examined for the presence of Staphylococcus aureus in nine different body sites. Seven rabbitries experienced epidemically spreading signs of staphylococcosis while the other 12 rabbitries did not. S. aureus was isolated in all seven flocks that suffered from chronic problems of staphylococcosis and in 11 of the 12 clinically healthy flocks. The mean percentage of infected animals in these two groups was 90 and 43.3%, respectively. S. aureus was isolated from all body sites examined, but the ear and the perineum were often more intensely colonized. The number of animals colonized with S. aureus and the mean number of positive body sites in S. aureus positive rabbits were significantly higher in rabbitries with chronic staphylococcosis. This indicates that colonization capacity of S. aureus plays a role in epidemically spreading disease in rabbits. S. aureus isolates belonged to five different biotypes and 23 different phage types. Several different types simultaneously circulated in contaminated rabbitries and even simultaneously infected individual rabbits. Strains that belonged to the biotype-phage type combination mixed CV-C, 3A/3C/55/71 only occurred in rabbitries chronically dealing with signs of staphylococcosis. This may indicate a relationship between phenotypic strain properties and virulence of S. aureus.  相似文献   

2.
Four groups of 12 rabbits each were inoculated in the nose with strains with suspected differences in virulence. In the two groups infected with strains from severe outbreaks, belonging to a rabbit-pathogenic biotype-phage type combination, 6-12 rabbits were found positive at the successive bacteriological samplings over a period of 28 days. In the two other groups, infected with strains obtained from rabbitries without a history of staphylococcosis, the number of Staphylococcus aureus positive animals quickly became negative but increased again after 1 week to 1-5 positive animals until the end of the experiment. Two rabbits in each group inoculated with a high virulence strain developed purulent skin lesions, while in the groups inoculated with low virulence strains, all animals remained clinically healthy. Results indicate that colonisation capacity is an important virulence determinant in rabbit staphylococcosis.  相似文献   

3.
High virulence rabbit Staphylococcus aureus strains, which are clonal in origin, are responsible for the spread of chronic staphylococcosis at the rabbit flock level. The aim of the present study was to develop a multiplex PCR assay that can be used for the identification of these high virulence strains. Two targets of the assay were the bbp and the selm genes, which have recently been shown to occur specifically in high virulence isolates. A third target was a sequence designated "flank", which was derived from a previously generated high virulence specific RAPD pattern. Furthermore, the femA gene, which is specific for S. aureus, was incorporated in order to avoid false negative results due to insufficient DNA preparation. The multiplex PCR was successful at differentiating the 26 typical high virulence and 50 low virulence rabbit S. aureus strains incorporated in the present study. Therefore it is useful for the initial screening of newly acquired breeding stock, in order to prevent the intake of high virulence strains in rabbitries.  相似文献   

4.
Staphylococcus aureus infections are a major problem in rabbitries. The main manifestations are subcutaneous abscesses, mastitis, pododermatitis and septicaemia. Two patterns of infection can be distinguished. In the first type, clinical signs remain limited to a small number of rabbits in a flock. This type has little economic importance and is caused by low-virulence S. aureus strains. In the second type, the disease shows an epidemic spread. Consequences are poor production results, infertility and death. This leads to chronic problems and a subsequent decline in production. The latter type is caused by high-virulence strains. Biotyping, phage typing and RAPD typing contribute to the characterisation of high-virulence S. aureus strains. Administration of antibiotics, disinfection of the environment and vaccination are not able to solve the problems. Therefore, the only effective measure is to cull the entire flock and to restart with a new rabbit population after thorough disinfection. Limiting the introduction of new rabbits in existing rabbitries and reducing contacts between rabbitries to an absolute minimum are currently the only way to face this most difficult problem.  相似文献   

5.
Randomly amplified polymorphic DNA (RAPD) analysis was performed on 95 pigeon S. gallolyticus strains of different virulence and belonging to different biotypes and different culture supernatant phenotypes as determined by SDS-PAGE. Four distinct RAPD patterns, designated A, B, C and D, were distinguished using primer OPM6 (5'CTGGGCAACT). All 76 strains generating RAPD pattern A or B were designated highly virulent on the basis of their SDS-PAGE pattern. Five of seven strains generating RAPD pattern C and 11 of 12 strains generating RAPD pattern D belonged to the moderately virulent and low virulent culture supernatant phenotype groups, respectively. Only one RAPD group C strain belonged to a highly virulent culture supernatant phenotype group. There was a correlation between biotype and RAPD patterns. These findings indicate that there is a high correlation between RAPD pattern and virulence for pigeons. Therefore, RAPD typing seems a rapid, reliable method to distinguish pigeon S. gallolyticus strains of high, moderate and low virulence.  相似文献   

6.
Western blot analysis was performed from the culture supernatant of 59 rabbit Staphylococcus aureus strains, classified as high and low virulence strains according to their epidemiological behaviour in commercial rabbitries, bio-, phage- and RAPD-type. Fourteen extracellular antigen bands (A-N) were recognised using sera of rabbits immunised with washed, viable high virulence S. aureus bacteria. Eleven of these bands were found in high virulence as well as in low virulence strains. The band A, approximately 78 kDa, was not seen in any of the 27 high virulence strains, except for one strain which was also typical in other aspects, was detected in all, but one of the low virulence strains. The M and N bands with molecular masses of approximately 29 and 27 kDa, respectively, were recognised in all high virulence strains except for the atypical strain, but in none of the low virulence strains. This indicates that the latter two antigens may be virulence-associated markers for S. aureus strains from rabbits.  相似文献   

7.
Fifty-six Staphylococcus aureus isolates recovered between 1998 and 2003 from 31 rabbit farms with and without problems of chronic staphylococcosis, were screened for resistance to enrofloxacin, erythromycin, gentamicin, lincomycin, neomycin, penicillin and tetracyclines using the agar dilution test. For penicillin, a disk diffusion test was also performed. The detection of tetP(B), tet(K), tet(L), tet(M), tet(O), tet(T), tet(W), erm(A), erm(B), erm(C) and mec(A) genes was done via a PCR assay. Four isolates showed resistance to erythromycin and lincomycin. These isolates were positive for the erm(C) gene in the PCR. Eleven strains were resistant to tetracyclines and all harboured the tet(K) gene. In the agar dilution test, five isolates showed resistance to penicillin, whereas in the disk diffusion test 12 isolates showed resistance. None of these 12 resistant isolates carried the mec(A) gene. Only one strain showed resistance to gentamicin, and all strains were susceptible to enrofloxacin and neomycin. This study demonstrates that resistance to antimicrobial agents in S. aureus isolates originating from rabbits is relatively rare compared to resistance in S. aureus isolates originating from other animals and humans.  相似文献   

8.
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9.
Two Staphylococcus epidermidis isolates from turkeys were used as interfering agents to help control staphylococcosis. Both isolates adhered to tissues of the turkeys' respiratory tract, interfered with attachment of virulent S. aureus, produced bacteriocins bacteriocidal to S. aureus, and were avirulent for turkeys. About 200,000 turkeys in commercial flocks were exposed to aerosols of these interfering isolates between 1 and 6 weeks of age, and many became colonized with these bacteria. The aerosol-treated turkeys had lower levels of colonization with S. aureus and had a 3% higher gross survival rate than untreated control turkeys.  相似文献   

10.
Previous studies indicated that Staphylococcus epidermidis strain 115 might be an effective interfering agent in reducing the rate of staphylococcosis in turkeys. In the present study, strain 115 was avirulent when administered to 3-day-old chicks by oral, aerosol, or intravenous route. Strain 115 adhered specifically to tracheal, lung, air-sac, and liver cells in vitro and interfered with subsequent colonization by virulent Staphylococcus aureus. In vivo colonization of lungs and livers of young chicks occurred following exposure to aerosols of strain 115. Strain 115 interfered with the in vivo colonization of lungs and livers by virulent S. aureus.  相似文献   

11.
An epidemiological survey was carried out to investigate the distribution of the VP7 and VP4 specificities of lapine rotaviruses (LRVs) in rabbitries from different geographical regions of Italy. Almost all the strains were characterized as P[22],G3, confirming the presence of the newly-recognized rotavirus P[22] VP4 allele in Italian rabbits. Only one P[14],G3 LRV strain was identified and two samples contained a mixed (P[14] + [22],G3) rotavirus infection. All the LRV strains analyzed exhibited a genogroup I VP6 specificity and a long dsRNA electropherotype. However, one of the P[14],G3 strains possessed a super-short pattern. Altogether, these data highlight the epidemiological relevance of the P[22] LRVs in Italian rabbitries.  相似文献   

12.
Staphylococcus aureus and various coagulase-negative staphylococci were isolated from turkeys with staphylococcosis. Virulent S. aureus adhered well (averaged more than 100 bacteria per tissue cell) in vitro to cells from tissues of the respiratory tract but did not adhere well (averaged fewer than 12 bacteria per tissue cell) to cells from tissues of the alimentary tract. Some avirulent coagulase-negative staphylococci also adhered well to cells from the respiratory tissues. Lungs and livers of turkeys became colonized with virulent S. aureus following experimental aerosol exposure. Tracheas, livers, and hock joints of some market-age turkeys were naturally colonized with S. aureus and various species of coagulase-negative staphylococci.  相似文献   

13.
为建立评价金黄色葡萄球菌毒力和用于筛选免疫保护性菌株的技术方法,选取小鼠腹腔攻毒方法确定的强毒力和弱毒力菌株各3株,经小鼠后腿肌肉注射不同剂量,比较20 d的临床病变差异,确定小鼠后腿内侧肌肉注射0.25 mL、OD600=0.6的剂量可以评价不同金黄色葡萄球菌的毒力。利用该方法比较了6株强毒力菌株的毒力差异,并用于2株免疫保护性菌株的筛选。结果证明建立的金黄色葡萄球菌毒力评价方法可以精确、客观比较不同菌株毒力差异,并可用于免疫保护性菌株的筛选。  相似文献   

14.
利用16S rRNA保守序列对引起贵州地区奶牛乳房炎的金黄色葡萄球菌进行分离鉴定,建立随机多态性扩增体系对金黄色葡萄球菌分离株进行基因分型研究。结果表明,69份奶样中共分离出金黄色葡萄球菌37株,DNA随机多态性扩增（random amplified polymorphic DNA,RAPD）结果显示这37株金黄色葡萄球菌扩增产物在1～7条带之间,产物大小为400～4500 bp。菌株可分为7个基因型,其中Ⅰ型7株（18.9%）、Ⅱ型2株（5.4%）、Ⅲ型2株（5.4%）、Ⅳ型1株（2.7%）、Ⅴ型19株（51.4%）、Ⅵ型1株（2.7%）、Ⅶ型5株（13.5%）,Ⅴ型为该地区的流行优势菌群。地理和气候环境对病原菌流行传播的影响是病原菌基因型分布差异的重要原因。  相似文献   

15.
Prevalence and some properties of Pasteurella multocida in rabbits kept at laboratory animal facilities and commercial rabbitries, and in their environment were investigated. A total of 1,147 nasal swab samples from 1,147 rabbits and 126 samples from their environment were subjected to the isolation of P. multocida. The bacteria were isolated from 199 (29.8%) of 668 rabbits in laboratory animal facilities and from 1 (0.2%) of 479 rabbits in the rabbitries. Isolation rate of P. multocida was low (0.9%) or high (44.9%) in the facilities with or without the monitoring for the presence of the bacteria, respectively. The highest rate of the isolation from rabbits was recorded at 10 to 12 months of their housing time. Thirty-nine cultures (31.0%) of air and the surfaces of floors, tips of water bottles, and cages were positive for P. multocida and isolation rate of the bacteria was high (78.6%) in the air. Biological and biochemical properties of the isolates were identical except for indole production and raffinose fermentation. The isolates were susceptible to antibiotics tested except for clindamycin, serologically similar in the gel-diffusion precipitin test and weakly virulent for mice. The present results suggested that these P. multocida isolates were the causal agent of rabbits rhinitis (snuffles) in Japan.  相似文献   

16.
甘肃地区牛源金黄色葡萄球菌分子鉴定及RAPD分型   总被引：1，自引：0，他引：1  
本研究目的是分离鉴定引起甘肃地区奶牛乳房炎的金黄色葡萄球菌,掌握其基因型情况。利用16S、23SrRNA保守序列PCR扩增对乳房炎奶样中的金黄色葡萄球菌进行鉴定,并进行RAPD基因分型。结果表明,310份奶样中共分离出金黄色葡萄球菌100株,RAPD结果显示这100株金黄色葡萄球菌均可得到清晰的RAPD指纹图谱,扩增产物在2～7条带之间,具有多种带型组成。通过聚类分析100株菌产生11个基因型,其中Ⅰ型4株,Ⅱ型4株,Ⅲ型10株,Ⅳ型13株,Ⅴ型7株,Ⅵ型24株,Ⅶ型16株,Ⅷ型6株,Ⅸ型4株,Ⅹ型10株,Ⅺ型2株。Ⅵ型为该地区的流行优势菌群,不同牛场各基因型菌株分布有明显差异。本研究说明牛场的环境与养殖条件对病原菌流行传播有明显的影响,这一结果对地区性奶牛乳房炎的防治提供了可靠的理论依据。  相似文献   

17.
从山东地区发病鸭中分离到一株新城疫病毒(SDLP09),经测定,其鸡胚半数致死量(ELD50)、鸡胚平均死亡时间(MDT)、1日龄雏鸡脑内接种致病指数(ICPI)、6周龄鸡静脉接种致病指数(IVPI)分别为107.84/0.1 mL、48.5 h、1.80、2.36,表明该新城疫病毒为强毒.通过分析其融合蛋白(F)发现,F蛋白多肽裂解位点为112RRQKRF117,符合NDV强毒株裂解位点氨基酸序列.F基因分型及氨基酸同源性比较发现,SDLP09株属于基因Ⅶ型,与野鸭源强毒NDV同源性更高,提示着该毒株可能来源于野鸭.  相似文献   

18.
Here we describe the application of a random amplified polymorphic DNA (RAPD) analysis for molecular genetic typing avian pathogenic Escherichia coli (APEC) strains. The RAPD technique was shown to be highly reproducible. Stable banding patterns with a high discriminatory capacity were obtained using two different primers. Overall, 55 E. coli strains were analyzed with a RAPD technique. The RAPD analysis showed that the E. coli strains isolated from poultry in Thailand and Sweden could be grouped into 50 of RAPD types by using these two different primer sets. Most of these different E. coli RAPD types were not geographically restricted. There was, as expected, a tendency of higher genetic relationship among E. coli strains isolated from the same farm. It is suggested that the RAPD technique may provide a rapid, low cost, simple and powerful tool to study the clonal epidemiology of avian E. coli infections.  相似文献   

19.
High virulence rabbit Staphylococcus aureus strains cause chronic and spreading problems of mastitis, pododermatitis and subcutaneous abscesses on rabbit flock level, whereas infections with low virulence strains are limited to individual rabbits. In the present report, 13 high virulence rabbit S. aureus strains, selected out of a large collection of strains isolated in five European countries between 1983 and 2004, were genotyped using pulsed-field gel electrophoresis, spa typing, multilocus sequence typing (MLST) and accessory gene regulator (agr) group typing. Two low virulence rabbit S. aureus strains were also included in the study. The results indicate the clonal origin of high virulence rabbit S. aureus strains present in Europe. Furthermore, the results of MLST and spa typing form a basis for international epidemiology of rabbit S. aureus strains, as these DNA sequence-based typing techniques can easily be used for intercentre comparisons.  相似文献   

20.
Fifty strains of Staphylococcus spp. isolated from bovine mastitis cases in several herds from different Argentinian provinces were screened for antimicrobial substances. Twelve strains exhibited a high antagonistic activity against the indicator strain (Corynebacterium fimi) and were chosen for further characterisation. The antimicrobial substances were sensitive to proteolytic enzymes suggesting that they might be bacteriocins (Bac). These strains were identified as S. aureus by the amplification of the femA gene. Plasmid profile analysis of these strains revealed the presence of at least one plasmid. Eleven strains carried a plasmid with a size similar to that of pRJ6 (8.0kb), which encodes aureocin A70, a bacteriocin produced by the Brazilian S. aureus strain A70 isolated from commercial milk. The other strain harboured a much larger plasmid. PCR experiments, using specific primers for amplification of the bacteriocin operon found in pRJ6, showed that all strains had the expected 525bp amplicon, suggesting that the bacteriocin produced may be related to aureocin A70. The genomic DNA of all Bac(+) strains was then analysed by pulsed-field gel electrophoresis (PFGE) in order to investigate clonal relationships amongst strains. Based on the results of PFGE experiments, 10 out of the 12 Bac(+) strains belonged to the same clone. The remaining two strains are possibly related to the prevalent clone. The aureocin A70 producer-strain belonged to a distinct clone.  相似文献   

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